Chapter 19: Ophthalmology

Accommodation: Change in the shape of the lens to compensate for changes in focal length. The term is also used more generally to mean the adjustment of the eye in general to compensate for focusing on objects at different distances.

Amblyopia: Poor, uncorrectable monocular (and rarely binocular) vision that is cortical in nature and not attributable to a structural abnormality of the eye or visual pathway. This may be a result of strabismus, high uncorrected refractive error, or visual deprivation during the critical period of cortical visual development during childhood.

Esotropia: Deviation of the eyes inward when compared with normal alignment.

Exotropia: Deviation of the eyes outward when compared with normal alignment.

Relative afferent pupillary defect (RAPD): The "swinging flashlight test" in a darkened room is used to test for a RAPD. The pupillary response should be equal in both eyes. A RAPD is detected when there is a relative difference in the pupillary response to a direct and consensual light stimulus between the two eyes. An eye with a RAPD will (abnormally) dilate with direct light to the eye but constrict normally in response to light shined in the fellow eye. A RAPD is seen when there is optic nerve damage or significant retinal disease (e.g., large retinal detachment, retinal artery occlusion, optic neuritis). One will not get a RAPD in refractive errors, vitreous bleeds, etc.

Strabismus: A general term that refers to a misalignment of the eyes. Esotropia, exotropia, and hypertropia (one eye deviated upward) are all examples of strabismus. The term strabismus says nothing about etiology, which can be congenital, neurologic, or muscular.

A mother presents with her healthy, 2-month-old male infant. She reports that for the past week his eyes have been noticeably crossed. He appears to fixate with either the right or left eye. She feels that aside from being cross-eyed, he seems to see well. On examination, his eyes are very crossed. When either eye is covered, he fixes and follows with the fellow eye and appears to have normal motility.

Question 19.1.1 The most likely diagnosis in this patient is:

A) Pseudoesotropia

B) Congenital esotropia

C) Accommodative esotropia

D) Sixth nerve palsy

Answer 19.1.1 The correct answer is "B." Esotropia is more common than exotropia. Congenital esotropia is generally found in children younger than 6 months. "C," accommodative esotropia, is the most common cause of esotropia in childhood and develops between age 6 months and 7 years. It is rare for accommodative esotropia to develop before 4 months or after 8 years of age. Pseudoesotropia is common in infants due to their flat nasal bridges and medial epicanthal folds, giving an appearance of esotropia. A simple way to assess children for a true strabismus is to shine a penlight in their eyes and evaluate the corneal reflection of your light. The light reflex will be in the same location bilaterally for pseudoesotropia but in different parts of the eye with true esotropia or other forms of strabismus (see Fig. 19-1).

FIGURE 19-1. Congenital esotropia. Note the large deviation with abnormal corneal light reflexes. The corneal light reflex of the left eye appears more temporal than that of the right eye. Therefore, the eye is deviated inward.

Question 19.1.2 Which of the following statements is FALSE?

A) Congenital esotropia is nearly always present at birth

B) Alternating fixation (e.g., the ability to fix on an object with either eye) is characteristic of congenital esotropia

C) Patients with congenital esotropia generally have normal amounts of hyperopia (farsightedness) for their age

D) Patients with a high degree of uncorrected hyperopia (farsightedness) can develop an accommodative esotropia

Answer 19.1.2 The correct answer (and the false statement) is "A." Congenital esotropia presents by the age of 6 months but is rarely present at birth. If true esotropia is observed at birth, it may be due to another neurologic disorder and further evaluation is indicated. Any form of strabismus may result in vision loss, and for this reason, it is important to treat strabismus early in life. The rest of the answers are true. Option "B": since patients have two eyes with equal vision, neither is preferred, so they will use both eyes to focus on objects (although not at the same time, of course!). Option "C": patients with congenital esotropia do have a normal degree of hyperopia for their age. "D" is also a true statement (see Fig. 19-2).

FIGURE 19-2. Accommodative esotropia improves when vision is corrected. Adaptation for near vision consists of accommodation (change in lens shape), miosis (constriction of the pupil), and convergence. This can eventually lead to an accommodative esotropia, which can easily be corrected with glasses. After glasses, the patient no longer uses the near response of accommodation and convergence, since the glasses are now providing the correction so the eyes resume normal alignment.

Question 19.1.3 Which of the following is NOT an appropriate treatment for strabismus?

A) Surgical correction if correction of refractive errors with full hyperopic spectacle does not resolve the strabismus

B) Patching the strabismic (misaligned) eye

C) Atropine drops or patching the nonstrabismic eye without surgery

D) Atropine drops or patching the non-strabismic eye plus surgery

Answer 19.1.3 The correct answer is "B." The goal of the treatment of strabismus is to prevent amblyopia. Amblyopia is commonly caused by strabismus (ocular misalignment), significant uncorrected refractive error, or disorders that distort images from the eye to the brain (i.e., congenital cataracts). In amblyopia, the brain "turns off" or suppresses the vision in the affected eye, thus allowing the unaffected eye to work unimpeded. In addition to surgical treatment (realignment, removal of cataract, etc.), amblyopia therapy and prevention is accomplished by blurring or impeding the vision in the unaffected (good) eye to strengthen the affected (bad) eye. This can be done by physically patching the good eye (not the strabismic eye as noted in "B") or by pharmacologic "patching" of the good eye using atropine drops if compliance with a patch is an issue (although eye patches remind kids of pirates and pirates are cool—aargh, matey!). NOTE: Terms such as "bad eye" and "good eye" are frequently confusing, so strabismic or deviated eye often replaces "bad eye" as no eye is truly bad, but rather a product of its environment, and "good eye" is usually reserved as a popular greeting in Australia (just say it like Russell Crowe would!).

Question 19.1.4 In which of the following situations would neuroimaging be necessary?

A) A 6-month-old with longstanding esotropia and equal visual acuity bilaterally

B) A 5-year-old with recent onset esotropia correctable by glasses

C) A 12-year-old with normal refraction and acute onset esotropia with diplopia

D) A newborn with a unilateral congenital cataract and an esotropia

Answer 19.1.4 The correct answer is "C." ANY unexplained new onset strabismus mandates an evaluation. A 12-year-old with acute esotropia and diplopia and no evidence of hyperopia requires neuroimaging to rule out any underlying neurological disorder. The age of the patient is older than that seen with congenital, acquired, or accommodative esotropia. The refraction is normal, so this does not fit with accommodative esotropia. Diplopia also suggests acute onset. Further workup is therefore necessary. "A" is incorrect because this is a classic history for congenital esotropia. "B" is incorrect because it is consistent with accommodative esotropia. Fixing uncorrected refractive error would be the appropriate first step here. Note that farsightedness (hyperopia) is a much more common cause of accommodative esotropia compared to nearsightedness (myopia). "D" is incorrect because we have reason for the esotropia—a congenital cataract is causing poor binocular fusion and coordination.

Objectives: Did you learn to…

• Describe the nomenclature of strabismus?

• Determine the underlying causes of esotropia?

• Recognize some unusual cases of strabismus that require further workup?

• Describe the risk and treatment of amblyopia?

A 50-year-old Asian female presents to the emergency department (ED) with severe nausea, vomiting, right eye pain, and blurry vision. She reports the symptoms began only a few hours earlier. She has no significant past medical history. On gross examination, her visual acuity is OD 20/200, her right eye is injected, and her right pupil is larger than her left. There does NOT appear to be a relative afferent pupillary defect (RAPD).

Question 19.2.1 With regard to this patient's presentation, which of the following would NOT be considered in the differential diagnosis?

A) Trauma secondary to blunt injury from a softball

B) Central retinal artery occlusion

C) Contact lens associated bacterial keratitis

D) Acute angle closure glaucoma

E) Anterior uveitis

Answer 19.2.1 The correct answer is "B." Among these choices, only central retinal artery occlusion would be painless and also associated with a RAPD (from diffuse retinal ischemia). All of the others will present with pain and WITHOUT a RAPD. "A," blunt injuries, may result in decreased vision secondary to corneal abrasions or edema, intraocular inflammation, hyphema, or retinal injuries. Injury can also cause injection and a traumatic mydriasis (dilation of the pupil). Direct and consensual pupillary reflexes would be normal (no RAPD) unless there was an associated traumatic optic neuropathy or significant retinal damage. "D," acute angle closure glaucoma, would cause diffuse injection with a mid-dilated pupil and no RAPD. "E," anterior uveitis, would also cause injection—but often only ciliary flush—and no RAPD. There is often asymmetry of the pupils in chronic anterior uveitis secondary to central posterior synechiae (adhesions between the iris and lens).

Question 19.2.2 Which of the following is required in order to diagnose acute angle closure glaucoma?

A) Slit lamp

B) Tonometer

C) Fluorescein and appropriate UV light

D) Snellen eye chart

E) A and B

Answer 19.2.2 The correct answer is "B." The most important examination technique used to diagnose acute glaucoma is intraocular pressure measurement. This could be achieved by Tonopen, Goldmann applanation tonometry at the slit lamp, Schiotz tonometer (anyone remember this antique?), assessed via digital palpation, etc. "A" is incorrect. A slit lamp is useful for diagnosing structural problems, iritis, etc. "C," fluorescein, is used to diagnose corneal injuries (de-epithelized cornea will take up fluorescein). "D," a Snellen eye chart, is used to determine visual acuity but is not necessary for diagnosing glaucoma. It is always a good idea to check vision in each eye in every patient with eye complaints; think of checking visual acuity as taking "vital signs" for the eye (see Fig. 19-3).

FIGURE 19-3. Acute angle closure glaucoma. Note the injection, hazy corneal reflex, and mid-dilated pupil.

Question 19.2.3 Which of the following is NOT a risk factor for acute angle closure glaucoma?

A) Hyperopia (farsightedness)

B) Asian descent

C) Male gender

D) Pharmacologic dilation

E) Increasing age

Answer 19.2.3 The correct answer is "C." Associated risk factors for acute angle closure glaucoma are hyperopia, Asian ancestry, female gender, and older age. Patients with hyperopia have smaller eyes and more shallow anterior chambers. Females and people of Asian descent also tend to have smaller eyes. As people age, cataracts may develop, become thicker, and crowd the anterior chamber, increasing the likelihood of developing pupillary block leading to glaucoma.

Question 19.2.4 Which of the following is NOT a presentation of acute closed-angle glaucoma?

A) Headache

B) Abdominal pain

C) Vomiting

D) Limitation of extraocular motion

E) Halos around light

Answer 19.2.4 The correct answer is "D." Patients with acute closed-angle glaucoma can present with all of the above findings except for the limitation of extraocular motion. Severe eye pain and blurred vision are commonly noted due to corneal edema and clouding secondary to the increased intraocular pressure.

You call your local ophthalmologist or optometrist to see this patient with suspected acute angle glaucoma. She is going to be delayed because of traffic—it's Iowa, so she's likely stuck behind a big tractor … we don't have "rush hour," only "rush minute."

Question 19.2.5 Which of the following drugs is NOT appropriate to use as a temporizing measure?

A) Topical carbonic anhydrase inhibitors

B) Topical β-blockers

C) Topical glycerin

D) Topical atropine drops

E) Topical prostaglandin analog drops

Answer 19.2.5 The correct answer is "D." Atropine is contraindicated in acute glaucoma since it will dilate the eye, exacerbating the problem. Topical β-blockers ("B") and topical ("A") or oral carbonic anhydrase inhibitors (e.g., acetazolamide) reduce aqueous production and thereby reduce intraocular pressure. In addition to the medications noted above, a topical α-adrenergic agonist (e.g., brimonidine, apraclonidine) also lowers eye pressure by selectively affecting the α-2 receptors and decreasing aqueous production. Topical glycerin ("C") is used to clear the corneal edema. Prostaglandin analogs ("E", e.g., latanoprost, etc.) increase aqueous outflow, thereby also decreasing intraocular pressure. It is generally third line after iridotomy for acute closed-angle glaucoma.

An ophthalmologist makes it to the hospital and recommends surgery.

Question 19.2.6 What is the definitive treatment of choice for acute angle closure glaucoma?

A) Laser peripheral iridotomy

B) Tapping of the anterior chamber to lower intraocular pressure

C) Aqueous suppressant therapy

D) Surgical iridectomy

E) Chiropractic manipulation of the iris

Answer 19.2.6 The correct answer is "A." The treatment goal is to allow the free flow of aqueous so that it does not accumulate behind the iris to push it forward to obstruct the trabecular meshwork. A laser peripheral iridotomy creates a small hole in the peripheral iris that allows aqueous flow to improve and thereby decreases intraocular pressure. As long as this hole remains patent, the patient is no longer at risk for an attack of angle closure glaucoma, and it is unusual for the hole to close unless there is a history of intraocular inflammation. "B," tapping the anterior chamber, can be used before laser therapy in order to clear the cornea so that visualization is better for the procedure. However, it is adjunctive and not a treatment of choice. Also, topical glycerin works well and can accomplish the same goal without being invasive. "C," aqueous suppressant therapy, is discussed in the previous question. "D," a surgical iridectomy, is performed for patients who are unable to sit still for the laser procedure (i.e., children, intellectually disabled). As to "E" … nothing against chiropractors, but this might not be the right time.

Question 19.2.7 Which is FALSE regarding closed- and open-angle glaucoma?

A) The main difference is that the drainage angle (trabecular meshwork) is closed in angle closure glaucoma and open in open-angle glaucoma

B) Scopolamine and other agents with anticholinergic properties are contraindicated in open-angle glaucoma but not in closed angle

C) Acute angle closure glaucoma usually occurs in hyperopic individuals while myopia is associated with open-angle glaucoma

D) The majority of people diagnosed with glaucoma have primary open-angle glaucoma

Answer 19.2.7 The correct answer (and false statement) is "B." Scopolamine and agents with anticholinergic properties, which would cause dilation of the pupil, are actually contraindicated in those with closed-angle glaucoma (and those with narrow angles who may not yet have obstructed). Once peripheral iridotomy is performed, anticholinergics are no longer an issue since the patient is no longer at risk. All of the rest of the statements are correct.

Question 19.2.8 Which of the following does NOT increase a patient's risk for primary open-angle glaucoma?

A) Family history

B) Caucasian race

C) Elevated intraocular pressure (>21 mm Hg)

D) Age >40

Answer 19.2.8 The correct answer is "B." Patients of African heritage are much more likely to develop open-angle glaucoma than are Caucasians and are also more likely to suffer vision loss from glaucoma. Family history, high intraocular pressures, and thin corneas are all risk factors for the development of open-angle glaucoma. High intraocular pressures lead to optic nerve damage. Minor risk factors include diabetes and myopia (nearsightedness). All patients should be screened for glaucoma as part of their routine eye examination. This is usually done by assessing intraocular pressure, examining the optic nerve and corneal thickness, and performing any ancillary diagnostic tests such as peripheral visual field analysis.

Question 19.2.9 Which of the following is typical of early open-angle glaucoma?

A) Central vision loss

B) Peripheral vision loss

C) Lack of symptoms

D) Decreased contrast

E) Blurring of vision

Answer 10.2.9 The correct answer is "C." Most people with early open-angle glaucoma are asymptomatic. This is why screening is important. A significant number of the approximately one million axons of the optic nerve may be damaged before this manifests itself as visual field loss. Examination of the optic nerve for abnormalities is the best way to diagnose early glaucoma. Later symptoms involve loss of peripheral or central vision.

Question 19.2.10 Which of the following is necessary to diagnose a patient with open-angle glaucoma?

A) Optic nerve head cupping or irregularity with corresponding visual field loss

B) Thin corneas

C) Elevated intraocular pressure

D) Narrow but open drainage angle

Answer 19.2.10 The correct answer is "A." Cupping of the optic nerve head is caused by thinning of the neural rim secondary to damage from high intraocular pressure. There should be a corresponding visual field defect consistent with the appearance of optic nerve cupping to diagnose a patient with glaucoma. In open-angle glaucoma, the mechanism of injury to the optic nerve is thought to be direct mechanical compression. Note that elevated intraocular pressure is not diagnostic of open-angle glaucoma. Glaucoma describes the changes to the optic nerve that are often secondary to ocular hypertension. Elevated intraocular pressure by itself is considered a risk factor for glaucoma. When not accompanied by cupping or visual field loss, it is considered ocular hypertension. Patients with ocular hypertension still need to be monitored and treated to prevent the development of open-angle glaucoma. Conversely, some patients with glaucoma never develop high intraocular pressure indicating that glaucoma may, in fact, be due to optic nerve damage arising from a variety of etiologies, the most common being elevated intraocular pressure. Thinner corneas ("B") increase the risk of glaucoma but are not required for diagnosis. "D" is incorrect. The drainage angle must be widely open—thus the name "open-angle glaucoma."

Question 19.2.11 Which of the following statements regarding glaucoma is true?

A) If treated early enough, normalizing the intraocular pressure can reverse the process of glaucoma and restore sight

B) The funduscopic examination in patients with glaucoma will generally show small retinal hemorrhages in addition to optic nerve cupping

C) Papilledema is seen with glaucoma as a result of increased pressure on the optic nerve

D) There are no identified genetic markers that correlate to development of glaucoma

E) None of the above

Answer 19.2.11 The correct answer is "E." So, wrong, wrong, wrong … and wrong. Once there is visual loss, it cannot be restored ("A"). Optic nerve hemorrhages, and not retinal hemorrhages, are seen in glaucoma ("B"). Retinal hemorrhages are typically seen with diabetic or hypertensive retinopathies. Papilledema results from increased intracranial—not intraocular—pressure ("C"). There are multiple genes that have been identified that contribute to the development of glaucoma ("D"). See Figure 19-4 for images of normal-appearing optic nerves, and compare these with Figure 19-5, which shows optic nerve findings in patients with glaucoma.

FIGURE 19-4. Normal optic nerve.

FIGURE 19-5. Glaucomatous optic nerve. Observe the cupping of the optic nerve head. The cup (central depression, seen as the bright part of the disc) of the optic nerve, which represents the axons diving down into the optic nerve, is larger compared with normal. A cup >50% of the disc width is indicative of glaucoma. Cupping represents damage to the optic nerve and fewer axons are present.

Objectives: Did you learn to…

• Recognize the signs and symptoms of acute angle closure glaucoma?

• Identify risk factors associated with acute angle closure glaucoma?

• Describe the pathology and basis for treatment for glaucoma?

• Differentiate between angle closure and open-angle glaucoma?

• Describe optic nerve findings in glaucoma?

Topical β-blockers lower intraocular pressure by decreasing aqueous production.

Which of the following is NOT considered a systemic side effect of these medications?

A) Bronchospasm

B) Bradycardia

C) Worsening of congestive heart failure

D) Increased low-density lipoprotein (LDL)

The correct answer is "D." β-Blockers do not increase LDL. The take-home message here is that topical β-blockers can have systemic effects including congestive heart failure and bradycardia. Be aware of this, especially in the elderly. Conversely, systemic medications such as steroids or β-blockers can also affect intraocular pressure.

A 70-year-old white female presents with sudden loss of the upper half of her vision in the left eye. She reports no pain. Her past medical history is significant for hypertension and type 2 diabetes.

Which of the following is the LEAST likely diagnosis given this history?

A) Retinal detachment

B) Branch retinal artery/vein occlusion

C) Optic neuritis

D) Anterior ischemic optic neuropathy

The correct answer is "C." Retinal detachment, branch retinal artery/vein occlusion, and anterior ischemic optic neuropathy all cause painless sectorial loss of vision in this age group. Optic neuritis usually occurs in a younger age group and is associated with pain and a central scotoma (blind spot).

Ischemic optic neuropathy is the most common cause of optic nerve lesions with visual loss in patients older than 50 years. It is referred to as "anterior" when it affects parts of the optic nerve behind the optic disc. It generally results from ischemia of the optic disc (sort of makes sense since it is called "anterior ischemic optic neuropathy").

Which of the following is CORRECT regarding nonarteritic (not related to temporal arteritis) anterior ischemic optic neuropathy (NA-AION)?

A) It is not associated with diabetes

B) Women are affected five times as often as men

C) As with giant cell arteritis, it responds quickly and dramatically to systemic corticosteroids

D) Avoiding nocturnal hypotension is an important aspect of treatment

The correct answer is "D." It is important to avoid nocturnal hypotension. Most eye specialists, therefore, recommend avoiding anti-hypertensive administration at bedtime. Occasionally, midodrine needs to be prescribed to support the blood pressure at night. The remaining statements are incorrect. Think of NA-AION as being equivalent to peripheral vascular disease: it is associated with hypertension, smoking, diabetes, etc. Males and females are equally affected. While the age of patients with NA-AION overlaps with that of patients with giant cell arteritis, the patients with NA-AION tend to be younger and NA-AION is painless. Unlike giant cell arteritis, steroids are not the treatment of choice.

A 65-year-old white male complains of "seeing wavy lines" or "window blinds" when looking at the doorway with his right eye. He has no pain or other ocular symptoms. His past medical history is significant for hypertension. He has a 40-pack-year smoking history. On examination, his visual acuity is 20/400 in the right eye. He has no RAPD and slit-lamp examination reveals that his anterior segment is normal. Examination of his right fundus reveals a subretinal hemorrhage involving his fovea.

Question 19.3.1 Which of the following is the most likely cause of this patient's vision loss?

A) Age-related macular degeneration (AMD)

B) Acute angle closure glaucoma

C) Cataract

D) Diabetic retinopathy

E) Malingering

Answer 19.3.1 The correct answer is "A." This is a typical presentation for AMD (continue to the next question for more information). "B" is incorrect because acute angle closure glaucoma presents with pain. "C" is incorrect since cataracts cause slowly progressive vision loss. "D" is incorrect: this would be an unusual presentation for diabetic retinopathy, and the patient has no known history of diabetes. Save "E" for the psychiatry chapter.

Question 19.3.2 Which of the following statements is FALSE?

A) AMD is the leading cause of severe central vision loss in persons older than 50 years in the United States

B) Smoking has been shown to be a risk factor in the development of wet AMD

C) AMD is less common in Caucasians when compared with other populations

D) The Age-Related Eye Disease Study Part 2 (AREDS2) has shown a beneficial effect of vitamin E, vitamin C, lutein, zeaxanthin, zinc, and copper in delaying the progression to wet AMD

E) The main presenting complaint of wet AMD is metamorphopsia, which is distortion or waviness centrally in the visual field

Answer 19.3.2 The correct answer is "C." AMD occurs more commonly in Caucasian populations. "A" is correct as AMD is the leading cause of central vision loss in patients older than 50 years. "B" is correct. Smoking is a significant risk factor in the progression to wet AMD; therefore smoking cessation is highly recommended in any individual with early AMD findings or with a strong family history of AMD. As to "D," the listed micronutrients are beneficial in delaying the progression from dry to wet AMD according to the AREDS2 results. "E" is also correct. Patients with AMD complain of distortion and/or waviness in the central visual field.

Objectives: Did you learn to…

• Recognize the signs and symptoms of AMD?

• Differentiate between dry and wet AMD?

• Recognize treatment modalities for wet AMD?

A 55-year-old white male with a history of newly diagnosed type 2 diabetes mellitus presents for routine evaluation. He has no complaints, including vision. On non-dilated direct ophthalmoscopic examination, both fundi appear to be normal.

Question 19.4.1 When should this patient be referred for formal ophthalmologic examination?

A) Immediately upon diagnosis

B) Within 3 months

C) Within 6 months

D) Within 1 year

E) When he develops visual symptoms, maybe 2 days before he goes blind

Answer 19.4.1 The correct answer is "A." Patient with type 2 diabetes should be referred for a dilated examination immediately upon diagnosis since they may have been undiagnosed for a long time period and may already have a degree of retinopathy. For type 1 diabetic patients, the recommendation is to refer within 5 years of diagnosis.

Question 19.4.2 What are the common findings seen on direct ophthalmoscopic examination in nonproliferative diabetic retinopathy?

A) Exudates

B) Cotton wool spots

C) Dot-blot hemorrhages

D) Microaneurysms

E) All of the above

Answer 19.4.2 The correct answer is "E." Direct ophthalmoscopic examination may reveal all these findings in nonproliferative diabetic retinopathy. These are caused by the increased fragility of capillaries and arterioles of the retina with diabetes. While hemorrhages and microaneurysms are unmistakably red, exudates and cotton-wool spots are white and fluffy in appearance.

Question 19.4.3 What is the main cause of vision loss in nonproliferative diabetic retinopathy?

A) Dot-blot hemorrhages

B) Macular edema

C) Cataract

D) Neovascularization

Answer 19.4.3 The correct answer is "B." Nonproliferative diabetic retinopathy by definition has no neovascularization (new, fragile blood vessel growth secondary to microvascular disease). The main source of decreased vision is macular edema. Treatment of focal macular edema consists of focal laser to leaking microaneurysms. If the patient has diffuse macular edema, a more extensive ("grid laser") pattern is used. Increasingly, treatment of nonproliferative diabetic macular edema may include intravitreal injection of antivascular endothelial growth factor (anti-VEGF); intravitreal triamcinolone acetonide is used rarely.

Question 19.4.4 What is the main cause of vision loss in proliferative diabetic retinopathy?

A) Cataract

B) Macular edema

C) Vitreous hemorrhage

D) Neovascular glaucoma

Answer 19.4.4 The correct answer is "C." Vision loss in proliferative retinopathy occurs when friable neovascular vessels break open and bleed (vitreous hemorrhage). Vision loss can also occur if the neovascular vessels grow over the drainage angle of the eye, causing glaucoma, although this is far less common than vitreous hemorrhage. See Figure 19-6 for an image of neovascularization.

FIGURE 19-6. Proliferative diabetic retinopathy. Neovascularization of the optic nerve.

The treatment of proliferative diabetic retinopathy consists of panretinal photocoagulation, which involves lasering the peripheral retina, thereby decreasing the ischemic drive for neovascularization. Treatment of vitreous hemorrhage includes observation with the head of bed elevated until the hemorrhage settles out and clears enough for laser treatment. Vitreous hemorrhages may be caused by other things, such as retinal detachments, so ultrasound is usually performed acutely, since one will not be able to adequately examine the retina after a significant hemorrhage.

Objectives: Did you learn to…

• Identify when to refer patients for formal ophthalmologic examination in type 1 and type 2 diabetes?

• Recognize the signs of diabetic retinopathy on direct ophthalmoscopic examination?

• Understand the causes of vision loss in those with nonproliferative and proliferative diabetic retinopathy?

• Describe the basis for treatment of both nonproliferative and proliferative diabetic retinopathy?

A 20-year-old male presents to the ED, complaining of a "bloody eye." He was in a fight earlier in the evening and was hit in the eye ("… but you should see the other guy!" … and with your luck, you probably will). You examine him and discover the findings in Figure 19-7. His visual acuity in the affected eye is hand motions only. He also has moderate edema of the lids but is able to open his eyes. On slit-lamp examination, the pupil appears normal. His motility is full and there is no diplopia.

FIGURE 19-7.

Question 19.5.1 What is the single most important first step in evaluation of this patient?

A) Detection of a RAPD

B) Patching until the heme clears

C) Evaluation for possible open globe

D) Immediate CT scanning to evaluate for an orbital fracture

E) Surgical anterior chamber washout of the heme

Answer 19.5.1 The correct answer is "C." This is a hyphema, with blood filling about one-third of the anterior chamber in Figure 19-7. More important is the history of trauma. The first, and most important, step in ocular trauma is to look for evidence of an open or ruptured globe. There should be no pressure placed on the eye until an open globe is ruled out. Signs of ruptured globe would be 360 degrees of conjunctival chemosis (conjunctival swelling), a shallow anterior chamber, an irregular or "peaked" pupil, or low intraocular pressure. However, a normal globe pressure does not rule out a ruptured globe. The leak may be small or may be plugged with choroid. NOTE: Intraocular pressure measurements should not be taken until an open globe is ruled out. If there is any doubt about whether there is an open globe, consult an ophthalmologist or optometrist. "D" is incorrect and deserves special mention: CT is not sensitive enough to rule out an open globe, even with thin cuts through the globe.

Question 19.5.2 Which is NOT a complication of hyphema (bleeding into the anterior chamber)?

A) Corneal blood staining

B) Glaucoma

C) Rebleeding

D) Iris heterochromia

Answer 19.5.2 The correct answer is "D." Complications of hyphema include rebleeding, which is most common in the first 3 to 5 days after injury. The hyphema may also stain the corneal endothelium, which may take months to clear. Glaucoma may also occur because of clogging of the trabecular meshwork by red blood cells, leading to a rise in intraocular pressure. "D," iris heterochromia, describes difference in iris coloring (e.g., one blue eye and one brown) and can be caused by a retained foreign body (e.g., iron) but is more often due to an underlying condition (e.g., neurofibromatosis) or designer contact lenses that can also be used at Halloween to look really freaky.

You rule out ruptured globe and orbital fracture. He's seen by the ophthalmologist on call who recommends treatment.

Question 19.5.3 Which of the following is the most appropriate treatment for this patient?

A) Treat at home with topical steroids

B) Hospital admission and IV steroids

C) Hospital admission and IV antibiotics

D) Hospital admission and topical antibiotics

E) Treat at home with topical antibiotics

Answer 19.5.3 The correct answer is "A." This patient has a hyphema, which is blood in the anterior chamber, usually due to direct trauma. While the party line in the past was that all of these patients require admission, sending a patient home with instructions to avoid further trauma and vigorous activities is sufficient in reliable patients with limited disease. However, an ophthalmologist or optometrist should be involved in this decision. In addition to topical steroids, other potential treatments include cycloplegic agents and perhaps antifibrinolytic agents such as aminocaproic acid.

OK. Time for a joke. What is the definition of a double-blind study? Two orthopedic surgeons reading an electrocardiogram.

Objectives: Did you learn to…

• Recognize the complications of ocular trauma?

• Examine a patient at risk for open globe?

• Identify the complications of hyphema?

• Initiate management of a patient with hyphema?

A 27-year-old male presents with irritation and redness of his right eye after hammering on an old iron fence. He was not wearing safety glasses at the time (they aren't very cool looking and he was hoping his attractive neighbor would be out gardening). He's now 3 days out from his injury. On examination, his visual acuity is 20/200. His right eye is injected, and his pupil is irregularly peaked to one side upon gross inspection. Slit-lamp examination reveals a laceration of his cornea extending to the limbus with a wick of iris occluding the laceration site. You place a Fox shield on the eye to prevent any pressure on the globe, update the patient's tetanus vaccine, and start antibiotics.

Question 19.6.1 What would be the next step in the evaluation and treatment of this patient?

A) Imaging for an intraocular foreign body by orbital CT scanning

B) Evaluation for an intraocular foreign body by orbital ultrasound

C) Try to remove the foreign body from the posterior chamber with a magnet

D) Complete ocular examination, including intraocular pressure and dilated funduscopic examination

Answer 19.6.1 The correct answer is "A." Given his history, the patient needs to be evaluated for a possible intraocular foreign body. The best imaging modality is with orbital CT scanning. Orbital ultrasound ("B") would also be appropriate, but for surgical planning CT scanning is preferred. "C" is incorrect because it is likely to cause more damage. This type of foreign-body removal is best left to a specialist in the OR. Finally, it would be best to defer intraocular pressure measurements until the extent of the laceration is evaluated since no pressure should ever be placed on a potential open globe.

The patient undergoes an orbital CT. There appears to be a piece of metal within his vitreous cavity.

Question 19.6.2 Which of the following are inert intraocular foreign bodies?

A) Iron

B) Copper

C) Glass

D) Aluminum

E) C and D

Answer 19.6.2 The correct answer is "C." Iron, copper, and aluminum are all reactive species and must be removed from the eye. Glass is inert and may be left in place, depending on the situation and the risk of surgery.

Question 19.6.3 Which is NOT a sign of a retained iron intraocular foreign body?

A) Iris heterochromia

B) Mydriasis

C) Glaucoma

D) Retinal degeneration

E) High refractive error

Answer 19.6.3 The correct answer is "E," also known as severe myopia or nearsightedness. Although, the patient in this case may have been extremely nearsighted in his decision to not wear safety glasses, we mean that metaphorically, and the retained iron foreign body has nothing to do with nearsightedness. All of the rest are signs of siderosis caused by a retained iron intraocular foreign body. Given the toxicity to the eye, the foreign body must be removed surgically.

Objectives: Did you learn to…

• Recognize the signs of a corneoscleral laceration?

• Manage a corneoscleral laceration in the emergency setting?

• Appreciate the effects of intraocular foreign bodies?

• Manage an intraocular foreign body in the emergency setting?

A 55-year-old farmer presents to the ED complaining of ocular pain and irritation. He reports accidentally splashing ammonia in both eyes. (In Iowa, this is usually from cooking meth—but not by farmers. Ammonia is used to produce meth, so meth cookers drill into tanks of anhydrous ammonia and problems occasionally ensue when they don't follow proper OSHA handling regulations. See all the fun things we are learning?) He attempted to rinse his eyes with water prior to coming to the ED. His visual acuity is OD 20/100 and OS 20/80. Both eyes are injected with corneal edema.

Question 19.7.1 What is the immediate first step in the treatment of chemical injuries to the eye?

A) Complete ocular examination, including dilated funduscopic examination

B) Manual removal of particulate material followed immediately by irrigation with saline until the pH is 7.0

C) Application of topical glycerin to clear the corneal edema

D) Topical anesthetic with debridement of surface epithelium

E) Build rapport by making small talk, asking about his tractor, etc.

Answer 19.7.1 The correct answer is "B." Step one: clean out the chemical. Any particulate matter should be removed prior to irrigation if it is a reactive substance (e.g., ammonium hydroxide crystals) since fluid may dissolve these causing more injury. The upper lid should be everted to check for any particulate matter. A moistened cotton swab may be used to sweep the superior/inferior fornices to remove any residual debris. Then, immediate irrigation with normal saline (or water—if saline is unavailable) is the next step even before completing the examination. A lid speculum should be placed and topical anesthesia applied. Irrigation may be administered by a handheld bottle or through IV tubing with an irrigation lens. The pH should be checked with a pH strip and irrigation discontinued when the pH reaches 7.0.

Question 19.7.2 Which of the following is a complication of chemical injuries to the eye?

A) Corneal ulceration

B) Inflammation

C) De-epithelialization of the cornea

D) All of the above

E) None of the above

Answer 19.7.2 The correct answer is "D." All of these are complications of chemical injuries to the eye. If you chose "E," you should take a break now. You are tired.

Objectives: Did you learn to…

• Describe the difference between acid and alkali injuries to the eye?

• Treat a chemical eye exposure in the emergency setting?

• Recognize the complications of chemical eye injuries?

A 25-year-old college student complains of redness, sensitivity to light, and tearing of her right eye for the past day. She lives in the dorm but reports no exposure to others with a red eye. For the past few days, she has had a sore throat and slight cough. You suspect she may have the dreaded "pink eye" (conjunctivitis).

Question 19.8.1 Regarding conjunctivitis, which of the following is FALSE?

A) Gonococcal conjunctivitis presents with severe hyperacute purulent discharge

B) Adenoviral conjunctivitis generally begins in one eye and spreads to the other eye

C) An enlarged preauricular node is a sign of allergic conjunctivitis

D) Toxic conjunctivitis has been associated with the use of topical antibiotics, antivirals, and preservatives

Answer 19.8.1 The correct answer (and FALSE one) is "C." There is no enlargement of preauricular nodes with allergic conjunctivitis. An enlarged preauricular node is a prominent feature of adenoviral conjunctivitis—which is extremely contagious (and no matter what the school says, does not respond to antibiotic eye drops). Allergic conjunctivitis tends to itch and affect both eyes. All other statements are true.

Your patient has no purulent drainage. On examination, her visual acuity is 20/40. Her right eye is diffusely injected and tearing; the left eye appears normal to inspection. She has a slightly tender right preauricular lymph node about 1 cm in size.

Question 19.8.2 What do you recommend as the initial treatment of this patient's conjunctivitis?

A) Symptomatic treatment with artificial tears four to eight times per day, cool compresses, and strict hygiene to prevent spread to the other eye or to other individuals

B) Treatment with topical vasoconstrictors/antihistamines QID for 1 to 2 weeks

C) Topical antibiotic treatment for 1 week so she can go back to class

D) Administration of topical steroids, artificial tears, and cool compresses

Answer 19.8.2 The correct answer is "A." This patient appears to have viral conjunctivitis, which is treated symptomatically. There is no need to treat with topical vasoconstrictors and/or antihistamines unless there is a significant itching component. It's not bacterial, so no antibiotics are needed. Additionally, prophylactic antibiotics are not necessary since there is rarely a secondary bacterial infection. Occasionally, corneal subepithelial infiltrates will develop that reduce vision and cause a foreign-body sensation. In these cases, topical steroids may be used, after other etiologies such as herpetic lesions have been ruled out, for 1 week then tapered to prevent significant scarring. However, this is rare. See Figure 19-8 for an image of hemorrhagic viral conjunctivitis generally from adenovirus, enterovirus and coxsackie virus. It is highly contagious.

FIGURE 19-8. Viral conjunctivitis. Note the follicles that are round collection of lymphocytes in the inferior fornix.

Question 19.8.3 If your patient is a part-time nursing assistant at a care facility, how long should she stay away from patient care?

A) Two days

B) Two weeks

C) Until her eyes are clear

D) Until she has taken antibiotics for 24 hours

Answer 19.8.3 The correct answer is "C." Viral conjunctivitis is highly contagious and is thought to be infectious as long as the eye is red and producing discharge. Promote good hand hygiene and avoidance of contact with others until the eye clears. In many instances, complete removal from school and/or work is not feasible, but patient education regarding the highly contagious nature of viral and bacterial conjunctivitis remains important.

Question 19.8.4 Which of the following is appropriate in the management of acute gonococcal conjunctivitis?

A) Conjunctival Gram stain and culture

B) Ceftriaxone IM/IV

C) Saline irrigation

D) All of the above

E) None of the above

Answer 19.8.4 The correct answer is "D." The hallmark of acute gonococcal conjunctivitis is severe purulent discharge, which occurs within 12 to 24 hours of infection. Preauricular adenopathy may also be seen. Management consists of Gram stain and culture of the purulent material to document gonococcus, administration of ceftriaxone (or spectinomycin if cephalosporin allergic) IM/IV plus azithromycin (for possible concurrent chlamydia infection), and eye irrigation. Fluoroquinolones are no longer recommended as initial therapy. See Figure 19-9 for an image of bacterial conjunctivitis and Figure 19-10 for an image Of Gonococcal ophthalmia neonatorum.

FIGURE 19-9. Bacterial conjunctivitis. Note the mucopurulent discharge.

FIGURE 19-10. Ophthalmia neonatorum. Note the severe mucopurulent discharge.

Question 19.8.5 Which of the following is NOT indicated in the treatment of allergic conjunctivitis?

A) Cool compresses

B) Artificial tears

C) Chronic topical vasoconstrictors/antihistamines

D) Short-term topical steroids

E) Diphenhydramine

Answer 19.8.5 The correct answer is "C." Given the possibility of rebound hyperemia with prolonged use, chronic vasoconstrictors/antihistamines are never indicated. Topical steroids should be reserved for severe cases and tapered over 1 to 2 weeks. Topical NSAIDs (ketorolac) and antihistamines or mast cell stabilizers (levocabastine or olopatadine) may be used to alleviate intense itching but are very expensive. Ketotifen is an effective and inexpensive OTC mast cell stabilizer and H1-antihistamine that, when used routinely, greatly decreases allergic conjunctivitis symptoms.

Objectives: Did you learn to…

• Differentiate among viral, bacterial, and allergic conjunctivitis?

• Not prescribe ophthalmic antibiotics for viral conjunctivitis—you got that, right?

• Choose appropriate treatments modalities for the various causes of conjunctivitis?

A patient complains of possible foreign body in her eye. She was scraping barnacles off the bottom of her multi-million dollar yacht currently dry-docked right next to one of Donald Trump's (Could she be a radiologist? Maybe a plastic surgeon?). She felt something fly into her eye and had immediate pain.

Question 19.9.1 Which of the following is FALSE regarding the use of topical fluorescein, which is used to highlight epithelial defects of the cornea?

A) Fluorescein is a nontoxic, water-soluble dye

B) It fluoresces under a cobalt blue filter

C) It exhibits positive staining of epithelial defects

D) Fluorescein does not penetrate the cornea

Answer 19.9.1 The correct answer is "D." Fluorescein does diffuse through the corneal stroma and causes a green flare in the anterior chamber. Rapid staining of the anterior chamber after the removal of a corneal foreign body suggests a large, deep corneal injury.

During your complete examination, you notice a small fleck of what looks like paint on the cornea. After successfully removing the piece of paint, you plan to discharge the patient.

Question 19.9.2 Which of the following is NOT an appropriate treatment for corneal abrasions?

A) Observation alone

B) Topical antibiotics

C) Cycloplegics

D) Topical steroids

E) Patching

Answer 19.9.2 The correct answer is "D." In uncomplicated corneal abrasions in non-contact lens wearers, observation alone is often adequate. Antibiotics should be used for all contact lens–related abrasions (or in non-wearers if you are particularly worried about the wound). Topical broad-spectrum antibiotics, such as polymyxin B/trimethoprim, are good first-line choices in those without contact lenses. A topical fluoroquinolone can be used in contact lens wearers. The patients should also be advised to withhold contact lens use until the abrasion is healed and should be evaluated by their contact lens prescribing provider. In many cases a bandage contact lens may be utilized by the patient's eye care provider to improve comfort and aid in healing. Patching may also be used for patient comfort but is unnecessary and may actually increase pain and prolong healing time. Topical steroids may inhibit epithelial healing and promote infection and should be avoided. "C" deserves special mention. Use of a long-acting cycloplegic is acceptable for discomfort related to severe photophobia and blepharospasm secondary to corneal abrasions. However, there is no data supporting (or refuting) their use in the treatment of corneal abrasions themselves.

As you already know, most corneal abrasion should heal within 24 to 48 hours. You ask the patient to follow up the next day to make sure that things are going well. On arrival (the fact that she followed up at all rules out the possibility that she is a physician … maybe an investment banker?), she notes increased pain in the eye with increased injection and photosensitivity. You place anesthetic drops in her eye but the pain does not resolve. The corneal abrasion seems to be healed.

Question 19.9.3 What do you expect to see on slit-lamp examination in her anterior chamber?

A) Cells and flare

B) Opacity of the lens

C) Foreign bodies of Schlemm

D) A tear of the anterior lens capsule

Answer 19.9.3 The correct answer is "A." This patient is presenting with typical posttraumatic iritis. Findings would be "cell and flare" in the anterior chamber. "B" and "D" are obviously not going to be a result of a superficial corneal abrasion. "C" is something we made up, but "Canal of Schlemm" is part of the eye and one of our favorite names in medicine—it is just humorous (humorous, get it? …ah, poor Schlemm).

Question 19.9.4 Appropriate treatment for this patient with post-traumatic iritis includes which of the following?

A) Topical antibiotics

B) Cycloplegic agents

C) Topical steroids

D) A, B, and C

E) B and C only

Answer 19.9.4 The correct answer is "E." Post-traumatic iritis is generally treated with topical steroids and cycloplegic agents. Again, we usually do this in consultation with an eye care provider. Of special note is "C." While we all worry about promoting infection with topical steroids, they can also increase intraocular pressure, and when used chronically, can cause glaucoma, which is generally more of a concern. So, these patients require close follow-up.

Assume that this patient was presenting de novo with iritis and it is not post-traumatic.

Question 19.9.5 Which of the following do you NOT have to worry about as an etiology of iritis?

A) Rheumatoid arthritis

B) Diabetes mellitus

C) Syphilis

D) Sarcoid

E) Lyme disease

Answer 19.9.5 The correct answer is "B." Iritis is an inflammatory process that can be caused by multiple underlying illnesses including ankylosing spondylitis, lupus (rarely), Behcet disease, syphilis, sarcoid, TB, Reiter syndrome, toxoplasmosis (common, even in non-immunosuppressed), juvenile idiopathic arthritis, and many others.

Objectives: Did you learn to…

• Remove a corneal foreign body?

• Use topical fluorescein in corneal abrasions?

• Manage uncomplicated corneal abrasions?

• Recognize iritis and its causes?

A 65-year-old white male with a history of hypertension, adult-onset diabetes, rheumatoid arthritis, and rosacea presents with chronic complaints of redness, tearing, and irritation OU. He sometimes also has "a film over his vision" that comes and goes. His ocular examination appears normal. He does, however, have an oily tear film with rapid breakup of his tears over his ocular surface. There is evidence of capped meibomian glands (sebaceous glands along his lid margins), but the eyelids are otherwise normal in appearance.

Question 19.10.1 Which of the following is the most likely diagnosis?

A) Meibomian gland dysfunction

B) Staphylococcal blepharitis

C) Hordeolum

D) Chalazion

E) Seborrheic blepharitis

Answer 19.10.1 The correct answer is "A." Meibomian glands are the sebaceous glands of the upper and lower eyelids, which are located along the posterior lid margin behind the lashes. These are punctate openings along the lid margin, which become clogged with thick secretions. When coupled with chronic inflammation of the lid margin, this eventually leads to an unstable tear film, creating symptoms of burning, redness, foreign-body sensation, and filmy vision. It is considered a form of blepharitis (inflammation of the eyelids). "B" and "E" are incorrect. Staphylococcal and seborrheic blepharitis have similar symptoms but involve the anterior eyelid margin at the base of the lashes (not the meibomian glands as noted in this case). Both typically have predominant signs of crusting or mattering. Seborrheic blepharitis often has crusting of an oily or greasy consistency. "C" and "D" are inflammatory processes, commonly but incorrectly grouped together as "styes." A hordeolum affects the anterior lid margin glands, which become acutely plugged and inflamed. A chalazion affects the posterior lid margin glands, which become plugged and chronically inflamed. "Stye" is typically synonymous with hordeolum; however, both hordeolum and chalazion grossly appear similar on examination.

Question 19.10.2 What part of his past medical history is associated with meibomian gland dysfunction?

A) Hypertension

B) Diabetes

C) Rheumatoid arthritis

D) Rosacea

Answer 19.10.2 The correct answer is "D." Meibomian gland dysfunction is associated with rosacea. Typical findings of rosacea include facial papules, pustules, telangiectasia, erythema, and rhinophyma.

Question 19.10.3 What treatment do you prescribe for this patient?

A) Observation and reassurance

B) Daily warm compresses, lid scrubs with dilute baby shampoo, and oral doxycycline, minocycline, or metronidazole

C) Erythromycin ophthalmic ointment PRN

D) Daily warm compresses, topical steroids, and frequent use of artificial tears

Answer 19.10.3 The correct answer is "B." The treatment of meibomian gland dysfunction consists of lid hygiene and doxycycline or minocycline 50 to 100 mg daily to BID for 3 to 6 weeks (which will also help treat the rosacea). The dosage may then be tapered according to symptoms. Gastrointestinal upset and photosensitivity are common side effects of doxycycline.

Seborrheic blepharitis is often treated with aggressive lid hygiene. Topical steroids are only used for short duration if there is significant inflammation present and should generally be prescribed by an ophthalmologist or optometrist for this condition. Topical therapies such as cyclosporine emulsion are aimed at lubrication and addressing chronic inflammation and are now available by prescription but are expensive and not that effective. Over-the-counter lubricating artificial tears can improve comfort but generally don't resolve the underlying condition.

Question 19.10.4 Which of the following is a common complication of meibomian gland dysfunction?

A) Bacterial keratitis

B) Preseptal cellulitis

C) Chalazion

D) Scleritis

E) Chronic conjunctivitis

Answer 19.10.4 The correct answer is "C." Meibomian gland dysfunction can cause a chronic granuloma to form behind the plugged meibomian gland, which is called a chalazion. The inflammation is sterile—unlike a hordeolum ("stye"), which is a painful purulent abscess. Treatment of a chalazion involves frequent warm compresses and massage. Topical antibiotics are of little value since it is sterile. If these measures fail, an intralesional injection of steroids or incision and drainage is warranted. Hordeola (styes) often resolve spontaneously but warm compresses and massage are often helpful. If there is any evidence of cellulitis, systemic oral antibiotics are indicated. Drainage using a needle may also be helpful. Topical antibiotics are often not effective.

Objectives: Did you learn to…

• Recognize the signs and symptoms of blepharitis and meibomian gland dysfunction?

• Describe the etiologies of blepharitis and meibomian gland dysfunction?

• Differentiate among meibomian gland dysfunction and staphylococcal and seborrheic blepharitis?

• Determine appropriate treatment for blepharitis and meibomian gland dysfunction and the complications of hordeola and chalazion?

A 7-year-old female presents with painful swelling and redness of upper and lower lids of her right eye. She reports having a bug bite near her right eye a week ago, and it's been very itchy. Now, it has become more erythematous and painful (infected, one might even say). On examination, her right eyelids are extremely edematous with a well-demarcated area of erythema. Her ocular examination is normal, including normal vision. She has no RAPD, proptosis, or motility deficit.

Question 19.11.1 This presentation is most consistent with:

A) Orbital cellulitis

B) Preseptal cellulitis

C) Anaphylactoid reaction to the insect bite

D) Blepharitis

E) None of the above

Answer 19.11.1 The correct answer is "B." The presentation of this patient is consistent with preseptal cellulitis, which is defined as inflammation/infection anterior to the orbital septum. This is less dangerous than orbital cellulitis, which occurs posterior to the orbital septum and has the risk of spread of infection into adjacent structures. "A" is incorrect. Infection occurring posterior to the orbital septum is called orbital cellulitis. This is characterized by fever, proptosis, restriction of globe motility, chemosis, and pain on eye movements. Orbital cellulitis can be complicated by subperiosteal abscess, cavernous sinus thrombosis, meningitis, or intracranial abscesses. "C" is incorrect since an anaphylactoid reaction is systemic.

Question 19.11.2 Which of the following is TRUE?

A) The most common cause of preseptal cellulitis in children is sinusitis

B) The most common cause of preseptal cellulitis in teens and adults is sinusitis

C) Orbital cellulitis is most commonly caused by bacteremia from a secondary source, as opposed to direct spread from an adjacent structure

D) The most common secondary source for orbital cellulitis is otitis media

Answer 19.11.2 The correct answer is "A." The most common cause of preseptal cellulitis in children is sinusitis. In contrast, teens and adults usually have preseptal cellulitis from a superficial source, such as skin trauma with inoculation.

Question 19.11.3 The most common pathogen causing preseptal cellulitis from a skin trauma with inoculation is which of the following?

A) Staphylococcus epidermidis

B) Haemophilus influenzae

C) Staphylococcus aureus

D) Streptococcus pneumoniae

Answer 19.11.3 The correct answer is "C."S. aureus is the most common pathogen of preseptal cellulitis from skin trauma. Some may have chosen "B." Prior to the introduction of the HIB vaccine, children younger than 5 years often had preseptal cellulitis secondary to H. influenzae. However, this is no longer the most common pathogen. Most cases of preseptal and orbital cellulitis in children are caused by Gram-positive cocci. Orbital cellulitis in children is usually caused by a single organism. In contrast, adults with orbital cellulitis frequently have polymicrobial infections including Gram-positive cocci, H. influenzae, and anaerobes. Mucormycosis should be suspected in diabetic patients and immunocompromised individuals.

Objectives: Did you learn to…

• Differentiate between orbital and preseptal cellulitis?

• Recognize conditions that predispose patients to these processes?

A 67-year-old white man with a history of coronary artery disease, hypertension, and peripheral vascular disease presents with the sudden onset of painless loss of vision OD several hours ago. He states he was watching TV when "things went black" in his right eye. He notes that this happened a few times before, but his vision always returned to normal after a couple of minutes. On examination, he has light perception vision, the presence of a RAPD, and a normal anterior segment of the eye. Upon funduscopic examination, the fundus appears diffusely white with a reddish hue within the macula (see Fig. 19-11).

FIGURE 19-11. A central retinal artery occlusion. Note the cherry-red spot in the macula, which is the normal choroidal circulation amidst the ischemic retina.

Question 19.12.1 The patient's history and examination are most consistent with which of the following?

A) Central retinal vein occlusion

B) Anterior ischemic optic neuropathy

C) Central retinal artery occlusion

D) Choroidal ischemia

Answer 19.12.1 The correct answer is "C." A central retinal artery occlusion is characterized by acute painless loss of vision. The ischemia and edema of the retina cause diffuse whitening. There is a cherry-red spot in the macula, which is the normal choroidal circulation amidst the ischemic retina (see Figure 19-11). The extensive ischemia causes a RAPD and significant visual loss. His previous history of recurrent episodes of loss of vision that returned to normal is consistent with amaurosis fugax.

Question 19.12.2 In a patient with this history, irreversible retinal damage occurs after what time frame?

A) 10 minutes

B) 30 minutes

C) 90 minutes

D) 6 hours

Answer 19.12.2 The correct answer is "C." If central retinal artery occlusion is complete for more than 90 minutes, irreversible retinal damage and visual loss ensue. Patients should seek medical care immediately. Amaurosis fugax, or transient monocular blindness, is typically caused by carotid disease. It is often described as a curtain or shade coming over the vision. It lasts from a few seconds to 15 minutes. Patients with a history of amaurosis fugax should be evaluated for carotid and cardiac disease.

Question 19.12.3 Treatment for central retinal artery occlusion includes all of the following EXCEPT:

A) Thrombolytics

B) Digital compression/decompression of the globe

C) Oxygen

D) Increasing blood carbon dioxide levels (e.g., rebreathing)

E) Acetazolamide

Answer 19.12.3 The correct answer is "A." Therapy for central retinal artery occlusion is entirely aimed at dislodging the embolism, maintaining retinal viability, and reducing intraocular pressure (to increase the pressure gradient between the artery and the eye). This can be accomplished by digitally compressing (press hard!) then decompressing the eye with a finger (to dislodge the embolism), oxygen (which will increase oxygen delivery), increasing serum carbon dioxide levels by rebreathing (thus dilating intracranial arteries), and acetazolamide (to reduce intraocular pressure). To accomplish the goals of increasing oxygen and carbon dioxide, try using a nonrebreather facemask with supplemental oxygen.

Question 19.12.4 Comparing central retinal artery occlusion to central retinal vein occlusion, which of the following is TRUE?

A) Central retinal artery occlusion is more likely to be associated with giant cell arteritis

B) The main feature of both is retinal whitening with a cherry red spot

C) Central retinal vein occlusion usually results from atherosclerotic thrombosis, while central retinal artery occlusion results from hyperviscosity syndromes and hypercoagulable states

D) A RAPD is characteristic of central retinal artery occlusion but is not seen with central retinal vein occlusion

Answer 19.12.4 The correct answer is "A." Giant cell arteritis is seen in 1% to 2% of central retinal artery occlusion. However, a more limited anterior ischemic retinopathy is generally seen with giant cell arteritis. If a patient presents with symptoms of central retinal artery occlusion, but no embolus is visualized, he/she should be asked about symptoms of giant cell arteritis. "B" is incorrect because only central retinal artery occlusion is associated with retinal whitening and a cherry red spot. The appearance of a central retinal vein occlusion is one of tortuous dilated veins, optic nerve edema, and intraretinal hemorrhages/edema (the so-called "blood and thunder" appearance of the fundus—although since thunder is a sound, having something look like thunder makes no sense to us, but maybe we are just too literal.) "C" is incorrect because central retinal artery occlusion is usually caused by atherosclerotic thrombosis or emboli, while central retinal vein occlusion is associated more with hyperviscosity syndromes (e.g., polycythemia) and hypercoagulable states (e.g., protein C deficiency). In older patients with central retinal vein occlusion, the main risk factors include vasculopathic states such as hypertension and diabetes. "D" is incorrect because a RAPD can be seen with either syndrome. There is always an RAPD with a central retinal artery occlusion due to the diffuse distribution of ischemia. A RAPD may or may not be seen with a central retinal vein occlusion depending on the level of ischemia.

FIGURE 19-12. Central retinal vein occlusion. Note the dilated tortuous veins, optic disc edema, and retinal hemorrhage/edema.

Question 19.12.5 Further evaluation and treatment of a central retinal artery occlusion includes all of the following EXCEPT:

A) Topical timolol

B) ESR/CRP

C) Carotid doppler

D) Orbital MRI/MRA

E) Echocardiogram

Answer 19.12.5 The correct answer is "D." There is no need for orbital imaging in the management of a central retinal artery occlusion. All of the other choices are important management steps. In addition, blood pressure, fasting blood sugar or glycosylated hemoglobin, CBC, and PT/PTT should be done. If there is a suspicion of giant cell arteritis, an ESR/CRP should be checked. Other tests might include a rheumatoid factor, syphilis serology, serum protein electrophoresis, and antiphospholipid antibodies. A similar workup is warranted in central retinal vein occlusion, except there is no need to search for an embolic source with a carotid doppler and echocardiogram.

Objectives: Did you learn to…

• Recognize the symptoms of vascular disorders of the eye?

• Differentiate between central retinal artery and vein occlusions?

• Describe some causes of ocular vascular occlusions?

• Determine the appropriate systemic workup for artery and vein occlusions?

A 40-year-old white female presents to your ED complaining of seeing "little floating black spots" in her vision in the left eye. She also notes little sparks of light in the temporal periphery of the left eye. She noted this while shopping today at Wal-Mart. First, you think this may be the revenge of the gods for shopping at Wal-Mart instead of buying locally. But then, you gather your wits about you. On examination, there is no RAPD (she has normal direct and consensual pupillary reflexes). Confrontation visual fields demonstrate peripheral vision loss in the left eye. Dilated peripheral retinal examination reveals billowing gray folds. The macula appears normal, and her vision is 20/20 in that eye.

Question 19.13.1 Which of the following is the most appropriate step in the management of this patient?

A) Place a patch over the left eye

B) Refer to an ophthalmologist immediately

C) Lower blood pressure acutely with IV labetalol

D) Apply timolol solution to the affected eye

E) Offer reassurance

Answer 19.13.1 The correct answer is "B." This patient is presenting with urgent ophthalmologic disease. She has classic symptoms of retinal detachment—flashing lights, visual field disruption, and floaters. Also, the majority of her vision is still intact. In her current state, she has a high likelihood of retaining good vision. None of the other treatments offered do anything for retinal detachment. Specifically, "A" does nothing, "C" is treatment for hypertensive retinopathy, "D" is for glaucoma, and "E" is just plain nuts in this case.

Question 19.13.2 Risk factors for retinal detachment include all of the following EXCEPT:

A) Glaucoma

B) Aphakia (surgical removal of the lens, such as in cataract surgery)

C) Myopia

D) Trauma

E) Prior ocular surgery

Answer 19.13.2 The correct answer is "A." Glaucoma is not a risk factor for retinal detachment. Both myopia (nearsightedness) and aphakia (surgical removal of lens) are risk factors. Trauma and previous surgery also predispose to retinal detachments. Most persons with retinal detachment are older than 50 years. As patients age, the vitreous liquifies and contracts, and this vitreoretinal traction or tugging can cause a tear, detaching the retina from the posterior wall of the eye.

Objectives: Did you learn to…

• Suspect retinal detachment in patients presenting with "floaters" and "flashes?"

• Identify patients who are at risk for retinal detachment?

A 55-year-old white male complains of a gradual decrease in vision in both eyes. He notes glare with oncoming headlights while night driving. Despite this, he feels that he is able to read better without his bifocals.

Question 19.14.1 Based on the history given, which of the following is the most likely cause of this patient's complaints?

A) Retinal detachment

B) Cataracts

C) Glaucoma

D) Diabetic retinopathy

E) Presbyopia

Answer 19.14.1 The correct answer is "B." Progressive visual loss and glare from oncoming headlights while driving at night are common complaints caused by cataracts. The eye examination can confirm the diagnosis, as most significant cataracts are easily visualized. The red reflex is diminished bilaterally, and a haze of gray is observed over the lens. Symptoms of retinal detachment ("A") are more acute. Glaucoma ("C") and diabetic retinopathy ("D") are less likely, but could also be present. Intraocular pressures and a dilated eye examination should be completed to adequately assess and diagnose the patient's condition.

Question 19.14.2 All of the following conditions/medications are risk factors for cataract formation EXCEPT:

A) Corticosteroids

B) Trauma

C) Radiation

D) Calcium channel blockers

E) Diabetes mellitus

Answer 19.14.2 The correct answer is "D." All of the other choices are associated with cataract formation. Other risk factors include age, tobacco, alcohol, and sunlight (so, wear your UV blocking shades!).

Question 19.14.3 Of all of the patients with cataracts below, which one has an indication for cataract surgery?

A) A patient with no visual complaints with a visual acuity of 20/50

B) A patient with complaints of glare and inability to drive at night with a visual acuity of 20/40

C) An older patient with a history of monocular congenital cataract and best-corrected visual acuity of 20/100 in that eye

D) A patient with right monocular diplopia that resolves with new spectacle correction

Answer 19.14.3 The correct answer is "B." There is no strict visual acuity that determines the appropriate timing of cataract surgery. It is really a functional definition. If there are significant lifestyle limitations secondary to visual disability from a cataract, then cataract surgery is (potentially) indicated. "C" is incorrect. An older person with a history of congenital cataracts and poor best-corrected visual acuity most likely suffered from amblyopia; therefore, cataract surgery is unlikely to benefit such a patient. "D" is incorrect. Monocular diplopia (double vision from one eye only) is an indication for cataract surgery, but if new spectacle correction improves the diplopia, then cataract surgery is not necessary.

Question 19.14.4 Complications of cataract surgery include all of the following EXCEPT:

A) Endophthalmitis

B) Retinal detachment

C) Glaucoma

D) Hemorrhage

E) Meibomian gland dysfunction

Answer 19.14.4 The correct answer is "E." Meibomian gland dysfunction is a chronic condition as discussed previously in this chapter. Modern day cataract surgery is typically done by phacoemulsification with an intraocular lens implant. Phacoemulsification is an ultrasound method of fragmenting and aspirating the cataract. Although associated with fewer complications than older large incision cataract surgery techniques, the potential complications mentioned above still exist. Additional complications include: wound leaks, uveitis, macular edema, retained lens material, and vitreous loss.

Objectives: Did you learn to…

• Identify patients at risk for cataract development?

• Describe indications for cataract surgery?

• Recognize the symptoms and visual disability in those with progressive cataracts?

A patient presents to your clinic without vision symptoms but complains of a growth on the colored part of his eye (Fig. 19-13). The growth is painless and has been present for several years but is now getting to the point that it is pretty obvious. Strangers tend to stare. Children run the other way when they see him coming. He cries himself to sleep every night because of this.

FIGURE 19-13.

This growth is most likely due to:

A) Systemic inflammatory illness

B) Exposure to UV light and dust

C) Foreign-body granuloma

D) Trauma to the sclera and cornea with scarring

E) Any of the above can lead to this finding

The correct answer is "B." This is a pterygium, an overgrowth of conjunctival tissue, which is a result of recurrent exposure to UV light and high winds with dust. It is of no clinical significance unless it encroaches on the visual field or causes cosmetic distress. It is characterized by involvement of the cornea nasally or temporally as opposed to a pinguecula, which has a similar appearance but does not infringe upon the cornea. Careful history taking often uncovers a patient history of outdoor lifestyle (farming, construction, boating, etc.) or residing in a region more equatorial and, thus, more pleasant in February than the 40 degrees north latitude and sub-zero temps we endure here in the Hawkeye state.

A 40-year-old patient presents with a painful, red area on the eye (Fig. 19-14). He notes the gradual onset of severe pain of a boring nature with pain in the periocular area as well. He has a history of rheumatoid arthritis.

FIGURE 19-14.

What is the diagnosis?

A) Episcleritis

B) Pterygium

C) Scleritis

D) Pinguecula

E) Epidemic hemorrhagic conjunctivitis

The correct answer is "C." This is scleritis. Note the erythema and inflammation, which differentiates it from a pterygium. Scleritis may also be nodular in nature or diffuse. Scleritis can be easily mistaken for episcleritis, which may appear similar. Episcleritis is inflammation of the tissues overlying the sclera. One thing that differentiates episcleritis from scleritis is that patients with episcleritis do not have the severity of pain noted with scleritis. A pinguecula appears as yellowish, slightly raised nodules that are found on the conjunctiva nasal or temporal to the cornea. A pinguecula generally appears in middle age, has similar risk factors as pterygium, and removal is rarely indicated.

Which of the following is NOT a common cause of scleritis?

A) Wegener granulomatosis