Relevance of Multicolor Imaging in Type 2 Macular Telangiectasia

Purpose: To report the imaging characteristics of various clinical features in idiopathic macular telangiectasia (MacTel 2) on multicolor imaging (MCI) and compare its accuracy vis‑à‑vis color fundus photograph (CFP) and fluorescein angiography (FA). Methods: In this retrospective observational study, 54 eyes of 27 patients with MacTel 2 were included after institutional review board approval. Multimodal imaging with CFP, optical coherence tomography (OCT), MCI, and FA was done. Images were analyzed to identify and describe the clinical findings in MacTel 2. Sensitivity, specificity, and positive and negative predictive values were computed for the various imaging modalities in MacTel 2. Results: In this study, the MCI identified all the different clinical features of MacTel 2 in 100% of cases. The confocal blue reflectance (BR) image was more sensitive than CFP (100% vs. 96.3%) in identifying the loss of retinal transparency in MacTel 2. For other clinical features such as right‑angled vessels, superficial retinal crystals, and retinal pigment epithelial hyperplasia/plaques, the sensitivity of BR, and green reflectance (GR) image, was comparable to that of CFP. Confocal infrared reflectance (IR) images showed poor sensitivity in identifying the non-proliferative features in MacTel 2 (P < 0.001). Loss of retinal transparency was not picked up on IR image. Other features such as right‑angled vessels, superficial retinal crystals, and pigment plaques were seen in 20%, 4.6%, and 26.3% of cases, respectively. However, confocal IR images were superior to FA (100% vs. 47%) and CFP (100% vs. 15%) in identifying the extent and location of subretinal neovascular membrane. The confocal BR and GR images were unable to identify the choroidal neovascular membrane (P < 0.001). Conclusion: MCI is a useful and non-invasive imaging modality to identify the clinical features in MacTel 2. MCI can be used as a complementary imaging tool to CFP, FA, and OCT.