RT Book, Section A1 Knoop, Kevin J. A1 Palma, James K. A2 Knoop, Kevin J. A2 Stack, Lawrence B. A2 Storrow, Alan B. A2 Thurman, R. Jason SR Print(0) ID 1181039820 T1 Lens Dislocation T2 The Atlas of Emergency Medicine, 5e YR 2021 FD 2021 PB McGraw-Hill PP New York, NY SN 9781260134940 LK accessmedicine.mhmedical.com/content.aspx?aid=1181039820 RD 2024/03/28 AB Lens dislocation may result from blunt trauma to the globe. As the anterior surface of the eye is struck, there is compression in the anteroposterior dimension with resultant stretching of the globe along its equator in the medial-lateral plane. As this occurs, it stretches the zonule fibers, which suspend the lens in place, and they, along with the lens capsule, may become disrupted. The patient may experience symptoms of monocular diplopia or gross blurring of images, depending on the severity of the injury. Occasionally there can be dramatic visual fluctuations caused by the lens changing position with resultant phakic and aphakic vision. There is generally a lack of pain except if secondary angle closure glaucoma occurs from the lens causing pupillary block. On slit-lamp examination, the displaced crystalline lens appears as a crescent shape along its edge against a backdrop of the red reflex from the fundus. The edge of the subluxed lens may be visible only with pupillary dilatation. Use caution in dilating the pupil, as this may cause the lens to sublux into the anterior chamber, which occurs if all the zonule fibers are torn. Chronically, the lens may lodge in either the anterior chamber or the vitreous. Marfan syndrome, tertiary syphilis, and homocystinuria may be present and should be considered in patients presenting with lens dislocation.