RESUMO
PURPOSE: To describe the natural course of Type 2 idiopathic macular telangiectasia in terms of visual outcomes, causes of visual loss, and incidence of subretinal neovascular membranes (SRNV). METHODS: This retrospective observational case series consisted of chart review of 104 outpatients (203 eyes; 66 women, 38 men) who were diagnosed to have Type 2 idiopathic macular telangiectasia by clinical examination and fluorescein angiography between January 2000 and December 2008. Visual and anatomic outcomes were analyzed during a minimum follow-up of 1 year. RESULTS: The mean age of the patients was 57 years (range, 40-74 years). Nineteen eyes (18 patients) presented with SRNV; the number increased to 29 eyes (14%; 23 patients) by the final visit (mean follow-up, 31 months). Diabetes was common (59%) though retinopathy was initially absent or mild to moderate in 99% patients. Mean logarithm of the minimum angle of resolution best-corrected visual acuity declined from 0.35 to 0.43 by the last visit (P < 0.0001) overall; final mean logarithm of the minimum angle of resolution best-corrected visual acuity was 0.61 (20/80) in the eyes with SRNV and 0.40 (20/50) in eyes without SRNV. The latter group started with better best-corrected visual acuity than SRNV group and remained better at 1-year, 2-year, and final follow-ups (P ≤ 0.0002). Overall, 30 eyes (15%; 24 patients) lost ≥ 2 Snellen lines, the main causes being SRNV and intraretinal pigment migration. Of 128 eyes (including SRNV) with best-corrected visual acuity ≥ 20/40 at baseline, 98 (77%) retained stable visual status; 74 (71%) patients retained best-corrected visual acuity of 20/40 or better at least in 1 eye. CONCLUSION: Over a follow-up of approximately 3 years, most eyes with Type 2 idiopathic macular telangiectasia starting with good vision were found to retain status quo; sight-threatening complications developed in a minority of eyes; most patients retained good vision at least in 1 eye.