Quantitative analysis of hyperautofluorescent rings and progression in subjects with retinitis pigmentosa associated with retinitis pigmentosa GTPase regulator (RPGR) gene mutations.
Prospective observational study of 46 subjects. Ring area, horizontal and vertical diameter measurements taken from outer and inner ring borders. Intraobserver repeatability, baseline measurements, progression rates, interocular symmetry, and association with age and genotype were investigated.
Baseline ring area was 11.8 ± 13.4 mm2 and 11.4 ± 13.2 mm2 for right and left eyes, respectively, with very strong interocular correlation (r = 0.9398; P < 0.0001). Ring area constriction was 1.5 ± 2.0 mm2/year and 1.3 ± 1.9 mm2/year for right and left eyes, respectively, with very strong interocular correlation (r = 0.878, P < 0.0001). Baseline ring area and constriction rate correlated negatively with age (r = −0.767; P < 0.0001 and r = −0.644, P < 0.0001, respectively). Constriction rate correlated strongly with baseline area (r = 0.850, P < 0.0001). Age, but not genotype, exerted a significant effect on constriction rates (P < 0.0001), with greatest rates of progression seen in younger subjects. An exponential decline overall was found.
This study provides disease-specific baseline values and progression rates together with a repeatability assessment of fundus autofluorescence metrics. Our findings can guide future treatment trials and contribute to the clinical care of patients with RPGR-associated retinitis pigmentosa.
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.
*UCL Institute of Ophthalmology, University College London, London, United Kingdom;
†Moorfields Eye Hospital, London, United Kingdom; and
‡Queen's University Belfast, Belfast, United Kingdom.
Reprint requests: Michel Michaelides, MD, FRCOphth, UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, United Kingdom; e-mail: email@example.com
Supported by grants from the National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital National Health Service Foundation Trust and UCL Institute of Ophthalmology (United Kingdom), Fight For Sight (United Kingdom), Moorfields Eye Hospital Special Trustees (United Kingdom), Moorfields Eye Charity (United Kingdom), the Foundation Fighting Blindness (USA), Retinitis Pigmentosa Fighting Blindness (United Kingdom), and the Wellcome Trust (099173/Z/12/Z). M. Michaelides is supported by an FFB Career Development Award.
M. Michaelides consults for MeiraGTx and Astellas. The remaining authors have no conflicts of interest to disclose.