FEATURE EWAP MARCH 2022 7 by Ellen Stodola Editorial Co-Director Negative dysphotopsia: How to explain it and management strategies Negative dysphotopsia is an issue that patients may face following cataract surgery. While it frequently resolves on its own, several physicians said it’s important to discuss it with patients and explain what’s going on. Jack Holladay, MD, highlighted risk factors that make a patient more likely to develop negative dysphotopsia, though he said you can’t definitively predict who will experience the complication. There are risk factors that can predispose it, but it’s difficult to predict when it will happen and to whom. Dr. Holladay noted primary risk factors from a paper he wrote,1 including a smaller photopic pupil, larger positive angle kappa, the shape of the IOL, smaller axial distance of the IOL behind the iris, nasal anterior capsule overlying anterior nasal IOL, higher dioptric power if equi-biconvex or plano-convex, and if the optic-haptic junction of the IOL is not horizontal. Secondary risk factors include the edge design of the IOL (if it’s truncated vs. rounded), the material of the IOL, and negative aspheric surfaces. Patients who have a small pupil (around 1.5–2 mm) are at higher risk for experiencing negative dysphotopsia when in bright light, Dr. Holladay said. This article originally appeared in the December 2021 issue of EyeWorld. It has been slightly modified and appears here with permission from the ASCRS Ophthalmic Services Corp. Dr. Holladay said he tries to stress to physicians how important these identifying measures are in helping to recognize high-risk patients preoperatively. Negative dysphotopsia is caused by a gap in rays that pass through the lens that miss the lens. There’s not a gap before surgery with the natural crystalline lens, Dr. Holladay said. “There are no rays that make it into the eye that can get between the crystalline lens and the iris,” Dr. Holladay explained. “That gap appears as a dark crescent or circle where the rays are missing on the retina. “What we showed in our paper is as you adjust the lens and make that gap bigger and various things in the eye different, you can make that crescent move more temporally, and you can make the thickness wider or thinner by how much larger that gap is between the rays that miss the lens and the rays that pass through the lens,” he said.1 Nicole Fram, MD, noted that this is a complication that can happen with any type of lens. The patient often has had perfect cataract surgery and is seeing 20/20. However, they may see a dark shadow off to the side temporally. “The first thing you want to do is reassure the patient that you know what it is,” she said, adding that it’s also important to rule out any retinal or neurological pathology such as a retinal tear or detachment. Contact information Fram: drfram@avceye.com Holladay: holladay@docholladay.com Olson: RandallJ.Olson@hsc.utah.edu Slit lamp photo of secondary reverse optic capture with the optic prolapsed over the nasal and temporal capsule and the haptics in the capsular bag. Source: Nicole Fram, MD
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