Krypton Red Laser and Argon Green Laser Photocoagulation in the Treatment of Sick RPE Due to Age-Related Macular Degeneration

Abstract

Krypton red laser or argon green laser photocoagulation was carried out on 15 fellow eyes suffering from sick retinal pigment epithelium (RPE) due to age-related macular degeneration (AMD). All the eyes had an initial good visual acuily (no less than 6/24), but complained of declined visual acuity or visual quality. Patients were followed-up for 6–36 months. Visual acuity test, fundoscopy and fluorescein angiography were performed before treatment and periodically during the follow-up visits. Visual acuity remained unchanged in 10 eyes, improved in 1 eye and deteriorated in 4 eyes. In all the treated eyes visual acuity was better than in the nontreated first eye.Age-related macular degeneration (AMD) is the leading cause of new blindness in patients over 60 years old in the United States and other western countries (1,2,3), as well as in Israel. Today, there is a concept to treat AMD with laser photocoagulation only whenever there is a clear pathology such as elevation of the sensory retina due to focal leakage, detachment of the retinal pigment epithelium (RPED), or subretinal neovascularisation (SRNV) (4,5,6,7,8). Elderly patients who have lost central vision in one eye due to AMD may start to complain of visual decline in the fellow eye before a distinct lesion like RPED, central serous retinopathy-like or SRNV develops. This occurs in the presence of drusen and a typical fluorescein angiogram, which shows just a late diffuse staining of the posterior pole due to a late mild leakage through diseased RPE. This stage may be called “decompensated RPE” or “sick RPE”. There are no data concerning the rate of development of distinct AMD lesions from the sick RPE stage. However, most of sick RPE eyes later develope one or all of the above mentioned lesions, which ultimately lead to low vision or blindness also in that fellow eye. The incidence of developing a disciform lesion in the second eye in patients who had it in the first eye is quite high: Teeters and Bird in 1973 reported of 12% per year (9); Gass in 1973 reported of a 33% incidence in 4 years (2); Gragudas et al. reported an incidence of 30% during a follow up period of one to four years (10); Gregor and Bird’s results (11) suggested a constant risk of 12% per year of developing disciform lesion in the second eye during the first 5 years; Bressler et al. demonstated that exudative maculopathy developed in the second eye in 13% after one year, in 22% after 2 years and in 29% after 3 years (12). A lower incidence was presented by Strahlman et al., who showed a 3%–7% risk per year of exudative maculopathy developing in the second eye during the first three years (13).We present here 15 eyes that underwent laser photocoagulation for sick RPE when they were not yet harboring the previously mentioned distinct lesion of AMD.KeywordsRetinal Pigment EpitheliumMacular DegenerationLaser PhotocoagulationCystoid Macular EdemaFoveal Avascular ZoneThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.