Backgrounds: To evaluate changes in the thickness of ganglion cell-inner plexiform layer and macular retinal nerve fiber layer using ocular coherence tomography in patients exposed to hydroxychloroquine .
Methods: This was a retrospective, cross-sectional study of patients on hydroxychloroquine therapy. Ocular coherence tomography images showing ganglion cell-inner plexiform cell layer and macular retinal nerve fiber layer thickness were obtained and compared to controls. The relationship between the thickness of ganglion cell-inner plexiform and macular retinal nerve fiber layer, duration and cumulative dose of hydroxychloroquine were evaluated.
Results: In all, 219 subjects were included. The Thickness of the ganglion cell-inner plexiform thickness was significantly less than controls (p = 0.006). The average macular RNFL thickness was less in the study compared to the control groups, but not statistically significant (p = 0.389). There was no significant correlation between ganglionic cell-inner plexiform and macular retinal nerve fiber layer with duration, daily dose, or cumulative dose of hydroxychloroquine.
Conclusion: Thinning of the ganglionic cell- inner plexiform layer could be an early indicator of retinal toxicity before the appearance of clinical retinopathy.