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

Abstract

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). Prospective cross-sectional study. 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), andimaging with an original prototype AO-SLO system. All eyes with idiopathic macular telangiectasia were examined with fluorescein angiography (FA), confocal blue reflectance, and microperimetry. 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 ± 3.23mm(2)) was larger than the dark regions (2.45 ± 2.40mm(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 < .05 for all). Patchy dark regions were also seen in areas without FA abnormalities in 12 eyes. Higher mean retinal sensitivity correlated with greater mean cone density 0.5mm from the center of the fovea (type 1: P= .010; type 2: P < .001). 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.