Eyeworld

91 September 2018 EW MEETING REPORTER Risk factors for negative dys- photopsia include both primary and secondary factors, Dr. Shimizu said. Primary factors are a smaller photopic pupil, larger positive angle kappa, the shape of IOL, nasal ante- rior capsule overlying anterior nasal IOL, high dioptric power if eqi-bi- convex or plano-convex, and the optic-haptic junction of the IOL not being horizontal. Secondary factors include edge design, material of the IOL, and negative aspheric surface. Dr. Shimizu said that to treat dysphotopsia, physicians can use IOL exchange, piggyback IOL im- plantation, or reverse optic capture. Liliana Werner, MD, PhD, Salt Lake City, discussed "Causes of IOL Opacification Requiring Explanta- tion." She spoke about hydrophilic acrylic lenses and noted that the leading cause of opacification is calcification. It may present on the surface of the lens. Dr. Werner shared a study she did looking at this problem in several different IOLs. She said that this is a multifactorial problem, and she highlighted the role of IOL packages with silicone compounds, phosphate-buffered ophthalmic vis- cosurgical device, local conditions of calcium/phosphate supersaturation in the vicinity of the IOL surfaces or within their substance, and condi- tions with chronic breakdown of the blood-aqueous barrier. You have to know how to make the diagnosis of calcification during slit lamp examination, Dr. Werner said. She added that further inves- tigation is necessary to determine if localized calcification is a result of direct contact between the IOL sur- face and exogenous gas/substance, metabolic change in the anterior chamber due to the presence of exogenous gas/substance, or exac- erbated inflammatory reaction after multiple surgical procedures. Gerd Auffarth, MD, Heidelberg, Germany, presented "Preloaded Systems: Ins and Outs." Dr. Auffarth discussed clinical ease of injection, complications of injector systems, injector force analysis, and damage to injector systems. He noted com- plications that could occur relating with a CTR, would not fixate the lens in the sulcus, and would not utilize it for pediatric cases. Liliana Werner, MD, PhD, Salt Lake City, presented on a possible new indication for the femtosecond laser: IOL power adjustment. This involves a laser-induced chemical reaction in a targeted area of the IOL optic substance, and it involves localized increase in hydrophilicity and decrease in refractive index. Simultaneously, the laser builds refractive index shaping lens within the targeted area. This technology was developed by Perfect Lens (Irvine, California) and uses green light, low energy levels, and can be used with com- mercially available IOLs. Dr. Werner said that the IOL power adjustment by femtosecond laser can be used with hydropho- bic or hydrophilic acrylic IOLs. It's noninvasive, fast, and can be done under topical anesthesia, and multi- ple adjustments are possible. Sunrise Lectures Kimiya Shimizu, MD, Tokyo, Japan, presented "How to Avoid Dyspho- topsia," and detailed a study he did to investigate risk factors for dysphotopsia after cataract surgery by a multivariate analysis. His study included 213 eyes of 213 patients. Inclusion criteria included postop CDVA of greater than or equal to 20/20, same IOL material for both eyes, and in-the-bag fixation. Exclu- sion criteria included patients with corneal or retinal disease, those who had undergone corneal refractive surgery, and multifocal IOL implan- tation, among others. Dr. Shimizu discussed a post- operative questionnaire used in his study to ask patients about their satisfaction after cataract surgery. He described the logistic re- gression analysis done to look at dysphotopsia. In the study, 26.8% of patients had dysphotopsia; 24.4% had positive and 4.2% had negative. He found that factors relating to all dysphotopsia were age and IOL material. Positive dysphotopsia was related to IOL material, and negative dysphotopsia was related to age, axial length, and IOL material. continued on page 92

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