Abstract
Purpose:
The development of a subretinal neovascular complex constitutes a late vision threatening complication in Macular Telangiectasia (MacTel) type 2. Little is known as regards natural history of these lesions. In the present study we aim at identifying prevalence and baseline characteristics of neovascular complexes in patients with MacTel type 2 and assess progression over a two-year period.
Methods:
We evaluated morphological characteristics from fundus images and fluorecein angiograms (FA) of patients enrolled in the MacTel Study between 2005 and 2011 and had at least 2 years of follow-up. Patients at Gass Classification stage 5 of disease progression, defined as the presence of active neovascular complex and/or scar, were included in subsequent analysis. Reported findings included laterality, foveal involvement, presence of pigment or crystals, lesion size as well as their progression over 2 years.
Results:
62 eyes of 40 patients (out of a total of 970 eyes of 499 patients) were classified as stage 5 MacTel type 2, of which 22 patients had bilateral involvement. 44 eyes presented with inactive scars at baseline, while 18 had active NV. Of active lesions 4 were partially fibrosed. The fovea was affected in 38 cases, though only 6 out of 18 active NV complexes extended to the fovea. Lesion size evaluated on FA ranged between 0.25 and 4 disc diameters (DD) with a median of 1.5 DD. Pigment plaques were present in 50 (out of 62 eyes) and in 10 (out of 18) eyes with active NV. Crystals were identified in 8 eyes in total of which 3 in eyes with active NV. At 2 years 14 out of 18 cases of active NV at baseline had evolved into an inactive scar, of which 10 presented enlargement of lesion with a median difference in size of 0.5 DD. 5 eyes (out of 8) with active NV without pigment plaques had progressed to scarring with pigment at 2 years. Of 24 eyes with extrafoveal lesions, the fovea remained uninvolved in 23 cases at 2 years.
Conclusions:
The prevalence of stage 5 disease in MacTel 2 is low (6.4%). There is a low degree of symmetry in cases with bilateral involvement. Foveal involvement by scarred lesions is significant, though only one third of active NV extend to the fovea. Moreover the chance of extension to the fovea at two years is small. Presence of pigment plaques is common at baseline and becomes increasingly so both in size and number of affected eyes after 2 years.
Keywords: 461 clinical (human) or epidemiologic studies: natural history •
585 macula/fovea