Abstract
Purpose :
Hydroxychloroquine (HCQ) maculopathy can cause irreversible vision loss. Alteration of the parafoveal photoreceptors has been reported to be one of the earliest histopathological sign. The relationship between the ellipsoid zone reflectivity and cone density was recently demonstrated. The main objective of the study was to measure the outer retinal reflectivity in patients taking a HCQ regimen without proven toxicity on routine screening tests. The second objective was to investigate the relationship between the reflectivity measured and the screening tests outcomes.
Methods :
Consecutive patients visiting for HCQ toxicity screening in the Ophthalmology Department of the Besançon University Hospital (France) were included. All patients underwent a complete ophthalmic examination with a ten-degrees automated perimetry (with measurement of the foveal threshold and the mean 2-5 degrees), fundus autofluorescence, multifocal electroretinogram (with measurement of N1, P1 and N2 amplitudes in a 2-5° range) and spectral-domain optical coherence tomography with en-face reconstruction of the ellipsoid zone and the retinal pigment epithelium (with measurement of the absolute reflectivity expressed in greyscale in the 2-5° range).
Results :
Thirty-nine patients (76 eyes) were studied. None of them displayed a toxic maculopathy. The cumulative dose for HCQ ranged from 24 to 2400g (mean ±SD: 706g±620). Bivariate analysis showed a decreased in ellipsoid reflectivity with escalating cumulative doses of HCQ (linear regression, p<0.0001, r2 : 0,3). Reflectivity was also correlated with N1, P1 and N2 amplitudes (p<0.05). Finally, reflectivity was statistically correlated with 5 degrees threshold perimetry. (p<0.005).
Conclusions :
Parafoveolar ellipsoid reflectivity with en face OCT could be a rapid biomarker, repeatable and quantifiable to screen HCQ maculopathy at an early stage, a preclinical stage.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.