Bilateral Concordance of the Fundus Hyperautofluorescent Ring in Typical Retinitis Pigmentosa Patients

Abstract

Background: It has long been assumed that in retinitis pigmentosa, disease presentation and progression are symmetrical. This study investigated whether hyperautofluorescent ring size, one known marker of disease progression, is symmetrical in typical RP patients.

Materials and Methods: A total of 88 patients with typical retinitis pigmentosa were enrolled in the study. Each presented with a hyperautofluorescent ring when imaged at baseline with fundus autofluorescence (AF). Vertical and horizontal diameters were analyzed according to mode of inheritance and age group. Seven of 88 patients had data missing in one eye and were excluded from further analysis.

Results: There was no significant relationship between hyperautofluorescent ring diameter and inheritance mode. There was a tendency toward smaller ring size with age and 3.7% of subjects displayed marked asymmetry in ring size between right and left eyes, although their electroretinogram results did not differ. Overall, when patients were considered as a group, there was a high correlation between right and left eyes’ horizontal and vertical diameters (r = 0.99, p < 0.0001; r = 0.98, p < 0.0001). Comparing individual patients’ eyes, and accounting for measurement error, a smaller majority of patients displayed symmetry of the hyperautofluorescent ring in both dimensions (85.7% in the vertical dimension, 87.3% in the horizontal dimension).

Conclusion: This study confirmed the highly symmetrical nature of the hyperautofluorescent ring in RP patients, except in a small subgroup. AF results, which provide less variability per image, and are consistently interpreted between different observers, may be a more sensitive and reliable method for testing symmetry than many functional tests.

• Fundus autofluorescence
• hyperautofluorescent ring
• retinitis pigmentosa
• symmetry and asymmetry

Acknowledgements

We would like to acknowledge Jimmy Duong’s contributions to our statistical analysis.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Tharikarn Sujirakul was supported by Foundation Fighting Blindness grant CF-CL-0613-0614-COLU. The Edward and Shirlee Brown Glaucoma Laboratory is supported by NIH core grants 5P30CA013696 and P30EY019007, Research to Prevent Blindness (R01EY018213), the Research to Prevent Blindness Physician-Scientist Award, the Barbara and Donald Jonas Family Fund, the Schneeweiss Stem Cell Fund, New York State (N09G-302), the Foundation Fighting Blindness New York Regional Research Center Grant (C-NY05-0705-0312). Financial support for Sherry Shen was provided by NHLBI (5T35HL007616-3) and Fight for Sight.

S. H. Tsang is a Fellow of the Burroughs-Wellcome Program in Biomedical Sciences, and has been supported by the Bernard Becker Association of University Professors in Ophthalmology Research to Prevent Blindness Award, the Dennis W. Jahnigen Award of the American Geriatrics Society, the Joel Hoffman Fund, Gale and Richard Siegel Stem Cell Fund, Charles Culpeper Scholarship, Irma T. Hirschl Charitable Trust, Bernard and Anne Spitzer Stem Cell Fund, and Professor Gertrude Rothschild Stem Cell Foundation.