Abstract
Purpose :
To characterize functional and structural changes in hydroxychloroquine (HCQ) retinal toxicity after drug cessation.
Methods :
21 female patients (mean age 60 ± 11.4 years; mean time on HCQ 167.5 ± 90 months; mean dose 5.8 ± 1.9 mg/kg) with HCQ retinopathy were included. Patients were followed for 7-82 months after drug cessation with multimodal imaging (spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF)) and functional testing (visual acuity (VA), Humphrey Visual Field (HVF), and multi-focal electroretinogram (mfERG)). Study eyes were categorized into 1 of 4 severity stages by qualitative grading of SD-OCT foveal scan. Changes in outcome measures between time of drug cessation to time of last follow-up visit were computed and compared across severity stages.
Results :
Study eyes (n = 42) were classified on OCT criteria into: stage 1 (subtle changes confined to parafoveal region; n = 14), stage 2 (clear localized changes in parafovea; n = 15), stage 3 (extensive parafoveal changes; n = 7), and stage 4 (foveal involvement, n = 6). Mean VA across follow-up was stable in stages 1 and 2, but decreased significantly in stages 3 and 4. HVF measures were also stable for stages 1 and 2 but deteriorated in stage 3. mfERG testing demonstrated improvement in the R1/R2 ratio in stage 1 (mean change = -0.86), but did not demonstrate significant changes in other stages. Macular thickness analysis on SD-OCT showed retinal thinning in ≥1 of 9 ETDRS subfield for all stages, with stage 2 having the most subfields affected (6 of 9 subfields). In eyes for which an island of foveal ellipsoid zone (EZ) remained (7 stage 2 and 5 stage 3 eyes), progressive decrease in the foveal EZ band length was observed in 4 of 7 stage 2 eyes and 5 of 5 stage 3 eyes. Inspection of FAF images showed progression on a FAF grading scale for 16.7% of stage 1 eyes, 46% of stage 2 eyes, and 43% of stage 3 eyes.
Conclusions :
Following HCQ cessation, the structure and function of eyes with retinopathy were not static but demonstrated a range of changes during follow-up testing that correlate with retinopathy severity at time of cessation. Eyes with the least severe retinopathy (stage 1) show the least progression and have some evidence of functional improvement. These findings provide evidence for the clinical importance of early detection and prompt cessation to optimize long-term outcomes.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.