Optical coherence tomography angiography of macular telangiectasia type 1: Comparison with mild diabetic macular edema

Abstract

Objective: The present study aimed to investigate the characteristics of macular telangiectasia type 1 (Mac tel type 1) using spectral-domain optical coherence tomography angiography (OCTA) and compare them with the characteristics of mild diabetic macular edema (DME), to provide a new objective method for quick clinical diagnosis and treatment.

Methods: A retrospective comparative analysis of 9 Mac tel type 1, 15 DME, and 15 normal eyes was performed using fluorescein angiography, spectral-domain optical coherence tomography, and OCTA. The morphological changes, retinal vessel density, and nonperfused areas were evaluated using split-spectrum amplitude-decorrelation angiography algorithm.

Results: OCTA revealed obvious saccular capillary telangiectasia and loss of parafoveal vascular density of Mac tel type 1. However, a number of line segment hyperreflective signals around the macula and more distinct nonperfusion in DME were observed. The quantitative foveal avascular zone mean area in Mac tel type 1 was larger than that in the normal eyes (0.40 ± 0.06 mm² vs. 0.88 ± 0.19 mm² , P < 0.001). However, the area in DME (1.52 ± 0.38 mm² ) was larger than that in Mac tel type 1 (P < 0.001), and the foveal zone area in DME (1.127 ± 0.05 mm² ) was also lager than it in Mac tel (P < 0.05). The vascular density of the superficial layer reduced in both Mac tel type 1 and DME (compared with normal eyes). The difference between Mac tel type 1 (49.56 ± 5.23)% and DME(44.58 ± 3.82)% was significant in the superficial capillary layer (P < 0.01). The vascular density of the retinal deep layer also reduced in both Mac tel type 1 and DME (compared with normal eyes). The difference between Mac tel type 1 (53.78 ± 7.36)% and DME (53.64 ± 4.96)% was no significant in this layer (P > 0.05).

Conclusion: Morphological differences between Mac tel 1 and DME can be observed on OCTA. Superficial vascular density and non-perfusion area may serve as a quantitative method to identify them. Lasers Surg. Med. 49:225-232, 2017. © 2017 Wiley Periodicals, Inc.

Keywords: OCT angiography; macular telangiectasia type 1; mild diabetic macular edema; split-spectrum amplitude-decorrelation angiography; vascular density.