Treatment for Macular Telangiectasia Type 2.

Macular telangiectasia (MacTel) type 2 is a bilateral disease of unknown cause with localized retinal degeneration and characteristic changes of the retinal vasculature. Funduscopic findings include reduced retinal transparency, crystalline deposits, ectatic capillaries, blunted venules, retinal pigment plaques, foveal atrophy and neovascular complexes. Leakage of telangiectatic macular capillaries is a characteristic finding on fluorescein angiography, and neurosensory atrophy may be present on optical coherence tomography images. Furthermore, there is a specific depletion of macular pigment in the central retina. Depending on the development of neovascular membranes, a nonproliferative and a proliferative (neovascular) disease stage may be distinguished. To date, there is no evidence for an effective treatment of nonproliferative MacTel type 2. Patients with proliferative MacTel type 2 and hence decreasing visual function may benefit from intravitreal application of vascular endothelial growth factor inhibitors. Early treatment and a small size of the neovascular membrane might be predictive factors for visual function outcome.

VERY EARLY DISEASE MANIFESTATIONS OF MACULAR TELANGIECTASIA TYPE 2.

BACKGROUND: To report very early morphologic and functional alterations in patients with macular telangiectasia type 2. METHODS: Patients with asymmetric disease manifestations, in whom retinal alterations characteristic for macular telangiectasia type 2 were present in one but not in the apparently unaffected fellow eye, underwent multimodal imaging and functional testing (microperimetry, visual acuity, reading ability, Amsler test). RESULTS: Fellow eyes not allowing the diagnosis of macular telangiectasia type 2 based on hitherto diagnostic standards consistently showed a severely reduced directional cone reflectance (Stiles-Crawford effect). Optical coherence tomography revealed an asymmetric configuration of the foveal pit with focal temporal thinning most pronounced at 1° eccentricity. Topographically related, macular pigment optical density was reduced in a small wedge-shaped temporal paracentral sector, resulting in an increased signal on fundus autofluorescence and fluorescein angiography imaging. No functional deficits were detectable in fellow eyes. Haidinger brushes were perceived in the fellow eye but not in the affected index eye with pronounced loss of macular pigment. CONCLUSION: Specific morphologic alterations precede vascular alterations and functional deficits in macular telangiectasia type 2. The described alterations indicate a primarily degenerative process with a secondary retinal vascular phenotype, and may be helpful for early identification of patients and affected family members.

POOR LONG-TERM OUTCOME OF ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY IN NONPROLIFERATIVE MACULAR TELANGIECTASIA TYPE 2.

PURPOSE: To investigate long-term effects after intravitreal inhibition of vascular endothelial growth factor in nonproliferative macular telangiectasia type 2. METHODS: Nine patients with macular telangiectasia type 2 treated with 12 monthly intravitreal ranibizumab injections in 1 eye were investigated again after a mean follow-up of 6.0 ± 0.4 years. Functional assessment included best-corrected visual acuity and microperimetry testing. Morphologic investigations included optical coherence tomography imaging and fluorescein angiography. RESULTS: Mean visual acuity at baseline was similar in treated and control eyes (both 20/50; range: 20/32-20/125 in the treated eyes and 20/25-20/100 in the untreated eyes). None of the eyes had a neovascular membrane or a paracentral scotoma. At the last follow-up, more eyes of the treatment group had lost 2 or more lines on best-corrected visual acuity testing (4 vs. 1) and more eyes had developed an absolute paracentral scotoma (7 vs. 2). A secondary neovascular membrane had formed in four of the treated and in none of the untreated eyes. CONCLUSION: Vascular endothelial growth factor inhibition with monthly dosing over 1 year had no beneficial effect 5 years after cessation of therapy. The worse outcome in the treated eyes may be due to selection bias, small sample size, or a potential adverse effect of vascular endothelial growth factor inhibition in a degenerative, primarily nonvascular disease as macular telangiectasia type 2.