Surgical removal of subfoveal choroidal neovascular membranes in high myopia

Background: A study was carried out to elucidate the anatomical and functio nal outcome after surgical excision of subfoveal choroidal neovascular memb ranes in high myopia. Methods: Sixty-five patients with high myopia (greate r than or equal to 6 dioptars), well-defined subfoveal neovascular membrane s on fluorescein angiography and preoperative visual acuity less than or eq ual to 20/100 were selected for surgery. A standardized surgical technique was used in all cases, by a single surgeon. The main outcomes assessed were Snellen visual acuity, surgical retinal pigment epithelium defect and post operative perfusion of the choriocapillaris. Multifactor analysis of varian ce and chi-square/Fisher's exact test statistics were used to assess the as sociation between patients' pre- and postoperative characteristics and outc ome measures. Results: Follow-up ranged from 6 to 48 months (mean 16 months ). Mean postoperative visual acuity (0.18) was significantly better than me an preoperative visual acuity (0.09). Visual acuity improved by at least tw o lines in 29 eyes (45%) and was unchanged in 24 (37%). Overall, 43 eyes (6 6%) had visual acuity of 20/200 or better and 15 (23%), 20/60 or better. Pr edictive factors with a significant effect on final visual acuity were mean visual acuity, preoperative status of retinal pigment epithelium and posto perative perfusion of the choriocapillaris. Postoperative perfusion was det ected in 31 (48%) of the total 65 eyes and in 12 (67%) of the 18 eyes with normal retinal pigment epithelium at baseline. The mean postoperative retin al pigment epithelium defect was 4.6 times larger than the original neovasc ular membrane. In selected patients, SLO macular scotometry showed areas of retained retinal sensitivity within the atrophic scar. Conclusion: The nat ural history of subfoveal neovascularization in high myopia is rarely visua lly restorative. By contrast, sur surgical excision of the membranes is fea sible and may restore visual acuity in selected patients. This therapeutic approach merits a formal multicenter clinical trial.