Comparison of Cone Pathologic Changes in Idiopathic Macular Telangiectasia Types 1 and 2 Using Adaptive Optics Scanning Laser Ophthalmoscopy

Purpose To compare pathologic changes in the photoreceptors of eyes with idiopathic macular telangiectasia types 1 and 2 using adaptive optics scanning laser ophthalmoscopy (AO-SLO). Design Prospective cross-sectional study. Methods Eleven eyes with idiopathic macular telangiectasia type 1, 14 eyes with type 2, and 10 normal eyes underwent a full ophthalmologic examination, spectral-domain optical coherence tomography (SD-OCT), and imaging with an original prototype AO-SLO system. All eyes with idiopathic macular telangiectasia were examined with fluorescein angiography (FA), confocal blue reflectance, and microperimetry. Results Compared with normal eyes (29 017 ± 5507 cones/mm 2 ), those with idiopathic macular telangiectasia type 1 had significantly lower cone density on the temporal side (18 427 ± 4908 cones/mm 2 , P  = .010). The FA leakage area (5.90 ± 3.23 mm 2 ) was larger than the dark regions (2.45 ± 2.40 mm 2 ) on AO-SLO ( P  = .003)—which were observed only in the FA leakage area. Compared with normal eyes, those with idiopathic macular telangiectasia type 2 had significantly lower cone density in all areas ( P P  = .010; type 2: P Conclusions Idiopathic macular telangiectasia type-specific differences in the distribution of photoreceptor abnormalities were shown in the AO-SLO images. For both idiopathic macular telangiectasia types 1 and 2, visual impairment was associated with cone damage.