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CELLULAR IMAGING OF THE TAPETAL-LIKE REFLEX IN CARRIERS OF RPGR-ASSOCIATED RETINOPATHY

Kalitzeos, Angelos, PhD*,†; Samra, Ranjit, MBChB*,†; Kasilian, Melissa, BA*,†; Tee, James J., L., FRCOphth*,†; Strampe, Margaret, BA‡,§; Langlo, Christopher, PhD; Webster, Andrew, R., FRCOphth*,†; Dubra, Alfredo, PhD; Carroll, Joseph, PhD‡,**; Michaelides, Michel, FRCOphth*,†

doi: 10.1097/IAE.0000000000001965
Original Study: PDF Only

Purpose: To examine the features of the tapetal-like reflex (TLR) in female carriers of RPGR-associated retinopathy by means of adaptive optics scanning light ophthalmoscopy (AOSLO) and spectral domain optical coherence tomography.

Methods: Nine molecularly confirmed RPGR carriers and three healthy controls underwent ocular examination and the following retinal imaging modalities: color photography, near-infrared reflectance, fundus autofluorescence, spectral domain optical coherence tomography, and AOSLO. After identifying TLR areas across all imaging modalities, normalized local contrast of outer retinal bands on spectral domain optical coherence tomography was calculated and AOSLO-acquired photoreceptor mosaic analysis was performed.

Results: Seven carriers had TLR areas, which colocalized with increased rod photoreceptor reflectivity on confocal AOSLO and reduced cone photoreceptor densities. Parafoveal TLR areas also exhibited reduced local contrast (i.e., increased reflectivity) of the outer retinal bands on spectral domain optical coherence tomography (inner segment ellipsoid zone and outer segment interdigitation zone). Healthy controls did not show TLR.

Conclusion: The cellular resolution provided by AOSLO affords the characterization of the photoreceptor mosaic in RPGR carriers with a TLR. Features revealed include reduced cone densities, increased cone inner segment diameters, and increased rod outer segment reflectivity.

This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Adaptive optics scanning laser ophthalmoscopy affords the characterization of the photoreceptor mosaic in RPGR carriers with a tapetal-like reflex. Features revealed include reduced cone densities, increased cone inner segment diameters, and increased rod outer segment reflectivity.

*Moorfields Eye Hospital, London, United Kingdom;

Institute of Ophthalmology, Department of Genetics, University College London, London, United Kingdom;

Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin;

§University of Minnesota Medical School, Minneapolis, Minnesota;

Department of Ophthalmology, Stanford University, Palo Alto, California; and

**Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin.

Reprint requests: Michel Michaelides, FRCOphth, UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, United Kingdom; e-mail: michel.michaelides@ucl.ac.uk

Research reported in this publication was supported by grants from the National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital National Health Service Foundation Trust and UCL Institute of Ophthalmology, National Eye Institute (NEI) of the National Institutes of Health (NIH) under award numbers R01EY017607, R01EY025231, P30EY001931, T32GM080202, T32EY014537, and U01EY025477, Fight For Sight (United Kingdom), Moorfields Eye Hospital Special Trustees (R140032A), Moorfields Eye Charity (MEC1512B), the Foundation Fighting Blindness, Retinitis Pigmentosa Fighting Blindness, Research to Prevent Blindness (RPB), and The Wellcome Trust (099173/Z/12/Z). M. Michaelides is supported by an FFB Career Development Award. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH or NIHR.

None of the authors has any conflicting interests to disclose.

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© 2018 by Ophthalmic Communications Society, Inc.