Eyeworld

EW CATARACT 28 August 2018 Dr. Devgan used the Ladas Super Formula at www.IOLcalc. com to determine that an IOL of +18.5 (using an A constant of 119.2) would provide an emmetropic post- op result. However, a higher power slit lamp magnification displayed a Presentation of a pseudoexfoliation case for cataract surgery round area of deposits of pseudoex- foliative material. Even higher detail showed a zone of clearance on the anterior lens capsule. That was the result of the iris margin clearing the surface of the anterior capsule to remove pseudoexfoliative deposits in the ring-shaped area. The pa- tient also had deposits in the center and periphery of the anterior lens capsule. Pseudoexfoliative material can be dispersed throughout the anterior segment on the anterior lens capsule in a target manner—as found in this case—over the zonules and ciliary processes, on the iris, and in the angle of the eye. Additionally, iridodonesis or phacodonesis found at the slit lamp was an indication of severe zonular weakness. Dr. Devgan also looks for a shal- low anterior chamber in patients with pseudoexfoliation because it usually means that the entire lens- iris diaphragm is loose and pushing forward, thereby shallowing the anterior chamber. "This patient had an anterior chamber depth of just 2 mm in the setting of a 24 mm axial length. This is a high risk for loose zonules," Dr. Devgan said. Due to the high association with glaucoma, Dr. Devgan said such patients should be screened for optic nerve damage and treated if an elevated IOP is detected. Because pseudoexfoliation pa- tients may be more prone to inflam- mation, they should receive preop topical nonsteroidal anti-inflam- matory drugs, which will also help prevent intraop miosis. Dr. Devgan begins with an NSAID or steroid for a day or two preop. "We know that using NSAIDs before cataract surgery helps prevent pupil constriction; it keeps the pupil bigger, which is what we want," Dr. Devgan said. Additionally, the use of stronger dilating drops in the surgery center may give additional dilation. Nor- mally, Dr. Devgan uses phenyleph- rine 2.5%, but a 10% version of the same drug is helpful in such cases. "That may be able to get the pupil a little bigger so you don't have to struggle quite as much," Dr. Devgan said. "The main challenges are that the pupil is smaller and that the zonular structures holding the cataract are weaker." Deposits of pseudoexfoliative material identified preop in a cataract patient Range of deposits of pseudoexfoliative material identified in a preop exam Use of bilateral choppers to manually and gently stretch the pupil A zone of clearance on the anterior lens capsule stemming from the iris margin clearing the surface of the anterior capsule to remove pseudoexfoliative deposits in the ring-shaped area Source: Uday Devgan, MD Overcoming continued from page 27

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