To quantify and correlate ellipsoid zone and photoreceptor outer segment changes with visual acuity in Stargardt disease.
An institutional review board–approved study of 32 eyes with Stargardt disease was performed. After spectral domain optical coherence tomography, the macular cube was exported into a novel analysis tool and volumetric assessment from the ellipsoid zone to the retinal pigment epithelium was performed. Using this information, mapping was completed with en face representation of the height between the ellipsoid zone and retinal pigment epithelium. This analysis provided quantification of ellipsoid zone and photoreceptor outer segments, including atrophy (ellipsoid zone to retinal pigment epithelium thickness = 0 μm) and attenuation (ellipsoid zone to retinal pigment epithelium thickness <20 μm). These parameters were compared with visual acuity and controls (n = 12 eyes).
Visual acuity ranged from 20/30 to 20/250. The central foveal B-scan area of ellipsoid and photoreceptor outer segments was significantly less than controls (0.13 ± 0.05 mm2 vs. 0.17 ± 0.03 mm2, respectively, P = 0.0074). The central foveal B-scan mean thickness measured 22.52 ± 9.0 μm in Stargardt versus 30.0 ± 5.08 μm (P = 0.0096). Atrophy and attenuation were significantly higher in Stargardt patients (22% vs. 1%, P = 0.005 and 43% vs. 1%, P = 0.0002). Visual acuity directly correlated with ellipsoid zone/outer segment volume (R = 0.57, P < 0.005) and inversely correlated with attenuation and atrophy (R = −0.53 and −0.57; P < 0.005 for all).
Eyes with Stargardt disease frequently have significant disruption of the ellipsoid zone and outer segments. This degenerative change was successfully quantified with a novel assessment platform and identified correlates with visual function. This software provides the opportunity for quantitative assessment and possible longitudinal surveillance.
A novel ellipsoid zone mapping tool allows for quantitative assessment and en face visualization of the ellipsoid zone and photoreceptor outer segment changes in Stargardt disease.
*Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio; and
†Ophthalmic Imaging Center, Cleveland Clinic, Cleveland, Ohio.
Reprint requests: Justis P. Ehlers, MD, Cole Eye Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue/i32, Cleveland, OH 44195; e-mail: firstname.lastname@example.org
Supported by NIH/NEI K23-EY022947-01A1 (J.P.E.); Ohio Department of Development TECH-13-059 (J.P.E.); and Research to Prevent Blindness (Cole Eye Institutional).
S. Arepalli has no conflicting interest to disclose. E. I. Traboulsi: Sanofi (consultant), Retrophin (consultant), and Sparks Therapeutics (consultant). J. P. Ehlers: Bioptigen (consultant, patent), Thrombogenics (consultant, research grant), Synergetics (patent), Genentech (research grant), Regeneron (research grant), Leica (consultant), Zeiss (consultant), Alcon (consultant, research grant), and Santen (consultant).
The funders had no role in the design and conduct of the study, in the collection, analysis and interpretation of the data, and in the preparation, review or approval of the manuscript. J. P. Ehlers has had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.