Incidence of vitreoretinal complications following cyclophotocoagulation

Abstract

Dear Editor, We present our data on the risk of vitreoretinal complications after cyclophotocoagulation (CPC). In CPC, the ciliary epithelium is coagulated typically by a transscleral approach [1]. There is intense discussion about uncontrollable hypotonia with the risk of phthisis bulbi as a severe complication of CPC [2, 3]. Little is known about retinal complications of the procedure that are possibly related to a post-operative prostaglandin burst [4, 5]. Our hypothesis is that CPC leads to vitreoretinal complications such as macula edema or epiretinal gliosis. We have retrospectively evaluated 850 consecutive patients who underwent transscleral contact CPC with a diode laser (810 nm) between March 2004 and June 2008, for severe vitreoretinal complications requiring vitreoretinal surgery. The electronic patient files were reviewed for the analysis. In the 850 patients, a total of 1,693 CPC treatments were performed. Of these patients, 20 (2.4% of the patients, 1.2% of the treatments) had to undergo surgery for vitreoretinal conditions after CPC treatment. The diagnoses that led to vitreoretinal surgery were: epiretinal membranes and vitreofoveal traction (12 cases), retinal detachment (four), macular edema (one), choroidal neovascularization (one), endophthalmitis (one) and vitreous haze (one). Age and gender were apparently not risk factors for severe vitreoretinal complications after CPC. The mean age of the 850 patients was 67.5±2.0 years, and in the vitreoretinal complications group 66.4±13.5 years. The male:female ratio was 382:468 (0.816) compared to 8:12 (0.667) respectively. The mean number of CPC treatments applied to all the patients was 2.0±1.4, and to the patients with vitreoretinal complications 1.8±1.1. The average time between the last CPC and the vitreoretinal surgery was 336±39 days. To obtain an indication of whether the number of CPCs influences the risk of severe vitreoretinal complications, a subgroup analysis was done. Table 1 shows the incidence of vitreoretinal surgery for each subgroup. The coefficient of correlation between percentage of vitreoretinal surgery after CPC and total amount of patients in this subgroup was 0.25 (p=0.68). Thus, the number of CPCs does not seem to impact the risk for severe vitreoretinal complications. We carefully reviewed the medical history of each patient who had to undergo vitreoretinal surgery, to determine whether there were other possible reasons for vitreoretinal issues. Without exception, each patient had a history of multiple previous surgeries, and presented with complex combinations of ocular diseases. All had undergone one or more of the following operations: cataract extraction (13 cases), YAG capsulotomy (one), secondary lens implantation (one), deep scelerctomy (eight), YAG goniopuncture (three), trabeculectomy (two), retinal lasercoagulation (four), retinal cryocoagulation (one), or argon laser trabeculoplasty (two). Indications for CPC were: primary open-angle glaucoma (14), PEX-glaucoma (two), traumatic glaucoma (one), neovascular glaucoma (one) and congenital glaucoma (two). In addition to the reasons for Graefes Arch Clin Exp Ophthalmol (2009) 247:1565–1566 DOI 10.1007/s00417-009-1115-5