EyeWorld India September 2018 Issue

correction. He stressed that compli- ance is one of the keys to success. Dr. Hengerer said that there may be some limitations with the LAL. For example, small pupils or corneal scars do not allow UV light to go into the LAL. He would not use it 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 pos- sible new indication for the fem- tosecond laser: IOL power adjust- ment. 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 re- fractive index. Simultaneously, the laser builds refractive index shap- ing 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 described two short- term studies with rabbit models using this technology and shared results following laser adjustment, mentioning slit lamp exam and postop posterior capsule opacifica- tion (PCO) rates. In conclusion, she said that the IOL power adjustment by femtosec- ond laser can be used with hydro- phobic or hydrophilic acrylic IOLs. It’s noninvasive, fast, and can be done under topical anesthesia, and multiple adjustments are possible. No special protective spectacles are required, Dr. Werner said, and this could be used in corneal and cataract procedures. ‘Sunrise Lectures’ highlight a variety of topics Kimiya Shimizu, MD , Tokyo, Japan, presented “How to Avoid Dysphotopsia,” and detailed a study he did to investigate risk fac- tors 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 mate- rial for both eyes, and in-the-bag fixation. Exclusion criteria included patients with corneal or retinal disease, those who had undergone corneal refractive surgery, and mul- tifocal IOL implantation, 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 regres- sion analysis done to look at dys- photopsia. In the study, 26.8% of patients had dysphotopsia; 24.4% had positive and 4.2% had nega- tive. He found that factors relating to all dysphotopsia were age and IOL material. Meanwhile, positive dysphotopsia was related to IOL material, and negative dysphotop- sia was related to age, axial length, and IOL material. Risk factors for negative dys- photopsia include both primary and secondary factors, Dr. Shimizu said. Primary factors are a smaller photopic pupil, larger positive an- gle kappa, the shape of IOL, nasal anterior capsule overlying anterior nasal IOL, high dioptric power if eqi-biconvex or plano-convex, and the optic-haptic junction of IOL not being horizontal. Meanwhile, 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 viscosurgical device, local con- ditions of calcium/phosphate supersaturation in the vicinity of the IOL surfaces or within their substance, and conditions 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 investi- gation 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 exacer- bated inflammatory reaction after multiple surgical procedures. Dr. Werner discussed opacifi- cation in silicone lenses and said that these could also calcify in eyes with asteroid hyalosis. She did a large study showing that this can happen with any type of silicone lens. Dr. Werner noted the impor- 31st APACRS – from page 65