[The value of blue light reflectance analysis in the multimodal diagnosis of macular telangiectasia].

Differentiating idiopathic macular telangiectasia (MacTel type 1) from secondary macular telangiectasias remains challenging, and available diagnostic methods such as blue light reflectance (BLR) analysis are still underused. This study presents the case of a 80-year-old man with a visual acuity of 20/800 in the right eye (OD). Multimodal imaging revealed perifoveolar telangiectasias, diffuse loss of the foveal reflex, and hyporeflective intraretinal cystoid spaces consistent with edema. The patient received 18 intravitreal injections of anti-VEGF agents (aflibercept, faricimab), with improvement to 20/40 and subsequent stabilization at 20/50 OD. One year later he was diagnosed with intraretinal cavitations in the inner retinal layers, disorganization of the inner retinal layers, and formation of a lamellar macular hole. BLR analysis demonstrated hyperreflectivity along the temporal vascular arcades, indicating vascular sclerosis characteristic of a branch retinal vein occlusion in the past and increasing the likelihood of secondary macular telangiectasia. BLR analysis is a noninvasive and widely available method that can reveal perivascular changes not evident on color fundus photography or OCT, thereby refining the differential diagnosis and management of macular telangiectasias.