Swept source optical coherence tomography analysis of choroidal thickness in macular telangiectasia type 2: a case-control study

PurposeThere has been a recent interest in the association of macular telangiectasia (MacTel) type 2 with central serous choroidopathy and other pachychoroid disorders. This study was performed to assess the subfoveal choroidal thickness (SFCT) in patients with MacTel type 2 and compare it with healthy controls using swept source optical coherence tomography (SS-OCT).MethodsIt was a retrospective case-control study performed at a tertiary eye care center. The cases constituted patients with MacTel type 2 detected over the last 2years (April 2016 to March 2018). The controls were healthy adults with no posterior segment pathology. The patients were evaluated with color fundus photography, SS-OCT (Triton, Topcon Inc., Oakland, New Jersey, USA) and fundus fluorescein angiography. The cases were staged based on Gass and Blodi classification. SFCT was compared between the two groups.ResultsSixty-five eyes of 33 patients with MacTel were included. The controls consisted of 61 eyes of 33 healthy age-matched (p=0.81) and sex-matched (p=0.31) adults. The mean SFCT in cases (353.091.2m) was higher than controls (289.2 +/- 69.0m), and this difference was statistically significant (p=0.0001). The mean SFCT was different in various stages: 346.6 +/- 86.3m (stage 2), 334.6 +/- 90.2m (stage 3), 374.6 +/- 94.0m (stage 4), and 294.8 +/- 68.8m (stage 5), though this was not statistically significant (p=0.28).Conclusions The choroid in MacTel type 2 patients was significantly thickened as compared to controls. SFCT may vary as the structural changes worsen over time.