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.