Symmetry of inherited eye disease

Abstract

Purpose : To investigate whether three inherited retinal diseases are symmetrical enough for untreated fellow-eyes to be used as controls in clinical trials of gene- and cell-based treatments.

Methods : We retrospectively evaluated Goldmann visual fields from patients over the age of 10 years with molecularly-confirmed MYO7A-associated Usher syndrome (n=7), ABCA4-associated Stargardt disease (n=172), and CHM-associated choroideremia (n=23). All patients provided informed consent in accordance with the tenets of the Declaration of Helsinki. TruthMarker (iOS) was used to digitally trace the isopters from scanned versions of each visual field, generating an XML file. Fields were excluded from the study if the perimetrist marked the field as unreliable, or if incomplete data were collected. Visual field volumes were calculated from the traced isopters Visual field volumes were calculated from the traced isopters using the field-area method of Weleber et al., (1986) multiplied by the target luminance values given of Christoforidis (2011). The resulting paired data (OS and OD) from each visit were evaluated for concordance using Pearson’s r.

Results : Fields from both eyes were digitally traced from 396 independent patient visits. The resulting data showed extremely high concordance of the visual field volumes between right and left eyes (r²=0.93; p<2.2x10^-16).

Conclusions : We have devised a method to capture quantitative functional measurements from historical, longitudinal visual field data. Our results demonstrate that the pattern of progression of these three diseases is highly symmetrical, supporting the use of fellow eyes as a control in gene- and cell-based treatment trials.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Correlation of visual field volumes between right and left eyes (R² = 0.93).