TY - JOUR T1 - Reduced foveal cone density in early idiopathic macular telangiectasia JF - BMJ Open Ophthalmology JO - BMJ Open Ophth DO - 10.1136/bmjophth-2020-000603 VL - 6 IS - 1 SP - e000603 AU - Hongxin Song AU - Ethan A Rossi AU - David R Williams Y1 - 2021/01/01 UR - http://bmjophth.bmj.com/content/6/1/e000603.abstract N2 - Objective Idiopathic macular telangiectasia (MacTel) is considered primarily a vascular disease affecting juxtafoveal retinal capillaries. However, recent evidence suggests that neuronal changes may occur early in disease development. We used high-resolution adaptive optics retinal imaging to elucidate the foveal cone photoreceptor changes at a cellular level in patients with MacTel.Methods and analysis We used adaptive optics scanning light ophthalmoscopy (AOSLO) to evaluate the foveal cone photoreceptors in the less-affected eye of patients with asymmetric MacTel. AOSLO images of cone photoreceptors were obtained in a 4°×4° area centred on the foveola. Individual cone positions were identified within a 2°×2° area centred on the fovea, using semiautomatic cone marking software with manual correction, permitting calculation of a map of cone density.Results In all participants, one eye was affected with MacTel, the fellow eye was clinically normal or near normal, with visual acuity of 20/25 or better and subtle angiographic leakage. The foveal cone mosaics were continuous with tight packing and cones exhibited normal reflectivity. However, cone density was significantly lower for all participants (mean=80 733 cones/mm2) within 0.5° than the cone density previously reported for normal eyes.Conclusions Foveal cone density is lower than normal in the clinically less-affected eyes of patients with asymmetric MacTel. This suggests that cone photoreceptor loss may precede classic obvious vascular changes in idiopathic MacTel. ER -