Longitudinal analysis of Optical Coherence Tomography Angiography in Macular Telangiectasia Type 2

Abstract

Purpose : To assess longitudinal optical coherence tomography angiography (OCT-A) findings and its prognostic value for disease progression in Macular Telangiectasia Type 2 (MacTel).

Methods : Participants underwent a comprehensive ophthalmologic examination and multimodal imaging including color fundus photography (CFP), fluorescein angiography, OCT and OCT-A. Eyes were classified according to the CFP-based staging system by Gass and Blodi. Automated quantitative analyses of vessel density (VD), skeleton density (SD) vessel diameter index (VDI) were performed in the superficial (SRL) and deep (DRL) retinal as well as the avascular layer (ARL). Choriocapillaris was assessed for non-perfused area (CCNPA). Linear mixed effects models (LMEM) correcting for age, sex and the nested data structure of two eyes within one patient were employed to assess for differences between stable and progressing eyes and to investigate the impact on disease progression of each parameter.

Results : A total of 122 eyes of 61 patients (35 female, mean age 62.33 ± 10.15 years) were included in this study. There was a trend towards reduced SRL VD, SRL SD, and DRL SD in eyes which experienced disease progression compared to eyes which remained stable (p = 0.058, p = 0.055, and p = 0.071, respectively) during the mean observation period of 23 months (± 7.83 months). No differences were present in VDI and CCNPA. In a LMEM baseline BCVA was prognostic for future disease stage progression (p < 0.001). Also, SRL VD may be prognostic for future disease stage progression, however no statistical significance could be reached (p = 0.051). Future central retinal thickness was best predicted by the presence/absence of EZ loss at baseline (p < 0.012).

Conclusions : Quantitative OCT-A parameters showed a trend towards reduction in eyes that progressed to a more severe MacTel stage. Baseline BCVA, EZ loss, and SRL VD could serve as prognostic imaging biomarkers for clinical monitoring and future interventional clinical trials in MacTel. Longitudinal studies on a larger sample size are warranted.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.