Krypton red laser photocoagulation for subretinal neovascularization

Foveal ablation for subfoveal choroidal neovascularization

Untreated subfoveal choroidal neovascularization (SFCN) often progresses to destroy much central visual function. In this study, laser photocoagulation which included the entire foveal avascular zone was applied to SFCN in the second eye of 13 consecutive patients. Each patient had untreated SFCN in their first eye with visual acuity less than or equal to 20/400. Each second eye had SFCN of recent onset which was less than or equal to 1 disc diameter (DD) in size and visual acuity less than or equal to 20/200. In 10 of 13 (76.9%) treated eyes, SFCN was eliminated for 3 to 30 months. These eyes all retained strikingly better visual fields (Amsler or automated) than their fellow untreated eyes, markedly better subjective vision, and Snellen visual acuities of 20/70 to 20/400. Foveal photocoagulation may be useful in selected cases of SFCN with small neovascular nets and poor visual acuity.

Age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible severe visual loss in the United States in people over 50 years of age. The nonexudative stage includes hard drusen (associated with localized dysfunction of the retinal pigment epithelium [RPE]), soft drusen (associated with diffuse dysfunction of the RPE), and geographic (areolar) atrophy. These fundus changes may predispose the eye to develop the neovascular/exudative stages of AMD. Most patients who develop severe visual loss from AMD have this exudative stage. Treatment for AMD has been shown to be effective for only a small proportion of patients who have a well-defined choroidal neovascular membrane (CNVM) more than 200 microns from the foveal center. Even in successfully treated cases, severe visual loss is postponed only for about 18 months because of the high rate of recurrent CNVMs that extend into the fovea. Thus, despite recent breakthroughs in laser treatment for AMD, most patients who develop the exudative form of AMD will develop central visual impairment. At the present time, the only available treatments for the majority of patients who develop the exudative form of AMD are low vision aids. Investigators are currently evaluating whether treatment is effective for membranes within 200 microns of the foveal center. Future studies need to be directed toward further understanding of the pathogenesis, treatment and prevention of the blinding complications of AMD.

Subretinal neovascularization after focal argon laser for diabetic macular edema

The authors reviewed four cases of iatrogenic subretinal neovascularization after focal argon green photocoagulation for clinically significant diabetic macular edema. An inappropriate combination of small spot size with a high-power setting is the common feature in each case of iatrogenic subretinal neovascularization. Close follow-up with fluorescein angiography is used to identify iatrogenic subretinal neovascularization at an early, treatable stage. All four patients responded favorably to laser photocoagulation of the subretinal neovascular membrane.