S. C. Lin

Vascular effects on ciliary tissue from endoscopic versus trans-scleral cyclophotocoagulation

Aim: To determine the acute and chronic vascular effects of endoscopic cyclophotocoagulation (ECP) versus trans-scleral cyclophotocoagulation (TCP) in a rabbit model. Methods: 20 rabbits underwent ECP in one eye and another 20 rabbits had unilateral TCP. Five treated eyes from each group underwent endoscopic fluorescein angiography (EFA) of the treated ciliary processes at each of the following time points: immediate, 1 day, 1 week, and 1 month. Five untreated rabbits were used as controls. The NIH Image software program was used to trace ciliary processes in order to determine their mean intensity, as a measure of their perfusion. Histopathology was also performed on eyes from each time point. Results: Immediately and 1 day after laser, both TCP and ECP eyes demonstrated severely reduced or non-existent blood flow in the areas of treatment. TCP treated processes essentially remained non-perfused at the 1 week and 1 month time points. ECP treated processes showed some reperfusion at 1 week and greater reperfusion by 1 month. Histopathology confirmed the overall greater vascular occlusion seen with TCP. Conclusions: Chronic poor perfusion of the ciliary body after TCP may account, in part, for its efficacy, as well as the significant complications including hypotony and phthisis. Late reperfusion of this region after ECP may provide some insight into the differences in efficacy and complication rates compared to TCP.

Lens parameters as predictors of intraocular pressure changes after phacoemulsification.

PurposeTo evaluate intraocular pressure (IOP) change after cataract surgery in non-glaucomatous eyes with narrow and open angles (OAs) and its relation to novel lens parameters measured by anterior segment optical coherence tomography (AS-OCT).SettingUniversity affiliated hospital, Farabi Eye Hospital, Tehran, Iran.DesignProspective interventional case series.MethodsIn this prospective study, 85 non-glaucomatous eyes underwent phacoemulsification and lens implantation. Thirty-nine eyes had OAs and 46 eyes had narrow angles (NAs). IOP and biometric parameters were measured by AS-OCT preoperatively and 3 months after surgery. Change in IOP and its relation to biometric parameters, including lens vault (LV), anterior vault (AV), defined as the sum of the LV and the ACD, and relative LV (rLV), defined as the ratio of the LV to the AV, were evaluated. The main outcome measure was degree of IOP change after phacoemulsification.ResultsOf the 85 patients included in the analysis, 35 were male and 50 were female with an overall mean age of 62.2±8.9 years. The average IOP reduction was −4.95±2.26 mm Hg, from a preoperative mean of 17.12±2.47 mm Hg, at 3 months after cataract surgery. The amount of IOP reduction was significantly greater in the NA compared with the OA group. In multivariate linear regression analysis, preoperative IOP and AV were significantly associated with IOP decrease (all ≤0.03).ConclusionCataract surgery results in IOP reduction in both OA and NA eyes. The amount of IOP reduction is related to AV.