Clinical features of macular telangiectasia type 2 and comparison of staging system in Taiwanese patients

The purpose of this study is to report the clinical characteristics of macular telangiectasia type 2 (MacTel 2) in Taiwan.

Retrospective analysis of patients diagnosed with MacTel 2 over a 7-year period in Changhua Christian Hospital. Best-corrected visual acuity (BCVA), fundus photography, fluorescein angiography, optical coherence tomography (OCT), and OCT angiography (OCTA) images were reviewed. Differences in BCVA and central macular thickness (CMT) were compared between the initial/baseline and final visits. The staging was performed according to the Gass and Blodi classification and OCTA.

There were 38 eyes in 19 patients were collected (Male: Female = 5:14). The mean age at diagnosis was 65.90 ± 8.26 years and the follow-up duration was 39.26 ± 28.31 months. All patients had both eyes affected, and eight of the 19 patients had a history of diabetes mellitus (DM). The mean initial logarithm of the minimum angle of resolution (logMAR) BCVA was 0.40 ± 0.31 and the mean final logMAR BCVA was 0.61 ± 0.53. Difference of BCVA equal or more than two lines between both eyes was noted in 63.1% (12 of 19) of patients at the initial visit and in 78.9% (15 of 19) of patients at the final follow-up. The mean CMT was 224.42 ± 38.50 μm at baseline and 222.05 ± 40.27 μm at the final visit. OCT illustrated macular hole in three eyes of three patients. At the final follow-up, retinal-choroidal anastomosis was noted in 17 eyes. Subretinal neovascularization (SRNV) was not present in any eye.

Bilateral involvement, asymmetrical BCVA in both eyes, low incidence of SRNV, and high prevalence of DM were characteristics of patients of MacTel 2 in Taiwan.