Abstract
Purpose :
To report clinical examples of directional variability of the reflectance of photoreceptors in macular diseases.
Methods :
We reviewed the imaging data of 12 patients with either acute macular neuroretinopathy (AMNR) (n=3), macular telangiectasia (n=2), resolved macular edema (n=6) or surgically reattached retinal detachment (n=1). Multiangle, multimodal imaging comprised infrared reflectance scanning laser ophthalmoscopy, optical coherence tomography (OCT, Spectralis, Heidelberg Engineering) and flood-illumination adaptive optics (FIAO, rtx1 camera, ImagineEye) imaging. Images were taken coaxially and off-axis in the cardinal directions (average excentricity 2°). Direction-related changes of the intensity of the reflectance of photoreceptor structures were analyzed in the three modalities.
Results :
When comparing coaxial and off-axis imaging, foci of directional variations of the reflectance of photoreceptors were detected under the form of adjacent areas showing directional alternation of hypo and hyperreflectivity. Among these cases, the most dramatic directional changes were observed in the AMNR case. Directional changes were consistent among the three imaging modalities. These areas were variably located: over the entire macula in the AMNR cases, as a ring around central atrophic lesions in MacTel cases, as parafoveal patches in resolved macular edema cases, and as a mix of disseminated patches and lines in the reattached retina case. Most of the directional variability seemed to originate from the COST line.
Conclusions :
Directional reflectance of cone outer segments may be observed in a variety of retinal diseases, the most striking being seen in AMNR. Most of the observed variability originated from the COST line. The fact that there were adjacent retinal areas showing clearly divergent peaks of reflectance suggests that there was locally loss of the parallelism of photoreceptor outer segment. We conclude that photoreceptor disarray is commonly observed in retinal diseases. This approach may help to document the contribution of photoreceptor disarray in visual loss.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.