Abstract
Purpose :
To develop objective measures of retinal function for patient selection in gene therapy of hereditary retinal dystrophies(HRDs).We hypothesize that inner to total mean retinal reflectivity is an independent measure of retinal function
Methods :
We have performed a retrospective analysis of a genetically diagnosed RP patient cohort in a tertiary ophthalmological center with a dedicated HRDs service.Data analyzed included visual acuity(VA, ETDRS scale),intraocular pressure(IOP, mmHg),Optical Coherence Tomography imaging(OCT).A custom algorithm was implemented that measured the ratio of the mean reflectance of two areas of an OCT image in MATLAB.We have employed this algorithm to quantify the relative reflectance of the Retinal Nerve Fiber Layer(RNFL) to the retina.Correlation analysis was performed to estimate the interrelations between the different clinical and imaging parameters,Bonferonni corrected for multiple comparisons.All the statistical analyses were performed in MATLAB
Results :
We included 115 genetically diagnosed RP patients,with USH2A presenting as the most common genetic defect(23/115,20%).A preliminary analsysis of 60/115 patients is included.Our analysis has revealed a strong positive correlation between the OCT reflectivity ratio and VA in both eyes(OD:r=0.6269,p<0.0001,OS:r=0.5295,p=0.0001.Age was negatively correlated with VA in both eyes (OD:r=-0.3178,p=0.0245,OS:r =-0.4518,p=0.001).There was a weak trend towards negative correlation between age and the OCT reflectivity ratio for both eye(OD:r =-0.2840,OS:r=0.1857).Multiple regression analysis revealed both age and the OCT reflectivity ratio as independent predictors of visual acuity(p=0.0084)
Conclusions :
Preliminary results suggest the OCT reflectivity ratio between the RNFL and the retina serves as a predictor of retinal function in genetically diagnosed RP patients.The OCT reflectivity ratio value as computed here can be increased by either or a combination of higher mean reflectance of RNFL and/or lower mean reflectance of the retina.To the best of our knowledge,this is the first work correlating OCT reflectivity and visual function in RP patients.Such approaches can prove to be useful in RP and other HRDs when selecting candidates for gene therapy.Further analysis is needed to elucidate any possible correlation of the OCT reflectivity ratio and the standard analysis of retinal layers thickness by OCT
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.