An objective method of diagnosing hydroxychloroquine maculopathy

Abstract

Background: Hydroxychloroquine (HCQ) maculopathy is irreversible; primary prevention is done by regular monitoring. Guidelines of the Royal College of Ophthalmologists identify definite toxicity as having abnormal results of two screening tests, we present a quantitative method for interpreting these guidelines. Methods: We obtained ocular coherence tomography (OCT) scans of 100 patients who have been on HCQ for 5 years or more (patients) and 70 age-matched controls. Both groups had 10'2 visual field (VF) test. We used linear regression to determine the cut-off points for each of the eight Early Treatment of Diabetic Retinopathy Study (ETDRS) macular sectors for the VF and OCT. We calculated the probability of developing maculopathy using logistic regression. Results: Mean patient age: 59.9 years, 85% females, no statistically significant age difference between the patients and the control groups. Diagnosis: 64% rheumatoid arthritis, 14% Sjogren's syndrome, 16% systemic lupus and 6% various other rheumatology conditions. Mean duration of use was 6.3 years. Logistic regression results show strong negative correlation between the outer nuclear layer (ONL) volume and probability of toxicity. Goodness of fit was tested using Hosmer and Lemeshow test that indicates a high significance with a high P-value of 1. Conclusions: Combining the ONL volume reduction and VF retinal sensitivity reduction per each of the eight ETDRS macular sectors provides an accurate and objective way of diagnosing HCQ maculopathy, this helps busy eye units establishing an optometrist-led or virtual service because it is independent of the assessor's level of experience.

Hydroxychloroquine retinopathy screening guidelines: a false positive

“…The SD-OCT showed ONL thinning in 2/8 ETDRS sectors (5/8 previously) in the right eye and 3/8 ETDRS sectors (4/8 previously) in the left eye, figure 3, 19 February 2021. This no longer reaches our threshold for a diagnosis of HCQ retinopathy 6. ETDRS sector 4 (outer temporal) remained abnormal on SD-OCT after YAG laser capsulotomy, but 10–2 VF sector 4 reverted to normal after YAG laser capsulotomy.…”

“…The 10–2 VF tests were reliable. Testing in the right eye showed 8/8 Early Treatment of Diabetic Retinopathy Study (ETDRS) sectors were below the normal threshold and 7/8 ETDRS sectors were below normal threshold in the left eye,6 figure 2. The SD-OCT revealed outer nuclear layer (ONL) thinning in 5/8 ETDRS sectors in the right eye and 4/8 ETDRS sectors in the left eye, figure 3 6.…”

“…Testing in the right eye showed 8/8 Early Treatment of Diabetic Retinopathy Study (ETDRS) sectors were below the normal threshold and 7/8 ETDRS sectors were below normal threshold in the left eye,6 figure 2. The SD-OCT revealed outer nuclear layer (ONL) thinning in 5/8 ETDRS sectors in the right eye and 4/8 ETDRS sectors in the left eye, figure 3 6. The patient was instructed to cease HCQ treatment until further follow-up in a joint rheumatology and ophthalmology clinic and was referred for multifocal electroretinogram (mfERG) at a tertiary centre.…”

Visual Field Sensitivity Prediction Using Optical Coherence Tomography Analysis in Hydroxychloroquine Toxicity

“…In these point-to-point structure-function analyses in patients treated with HCQ, we identify multiple OCT-derived quantitative metrics that exhibit correlation with visual field sensitivity. Previous analyses of HCQ toxicity using the Early Treatment Diabetic Retinopathy Study (ETDRS) grid have identified OCT-derived metrics such as EZ loss, thickness measures such as TRT and ORT, and intensity-based measures such as MinI as being relevant and correlated to visual field mean deviations measured across the retina 6 , 21 or to the visual field sensitivity in the ETDRS subfield. 21 Our analyses build upon these results to resolve what aspects of structural change are driving retinal function in each tested location.…”

Rapid Macular Thinning Is an Early Indicator of Hydroxychloroquine Retinal Toxicity

“…7e9 De Sisternes et al 8 showed with segmentation OCT topography that retinal thickness in hydroxychloroquine users generally remains stable until near the time when retinopathy becomes evident and that thinning associated with toxicity occurs primarily in the outer retina. Hasan et al 10 described a technique that combines quantitative data from OCT studies and 10-2 visual fields to identify patients with hydroxychloroquine maculopathy, but their approach compares one-time measurements to statistical norms, which vary widely. Recently, Marmor et al 11 performed a pilot study of patients followed until the appearance of conventional OCT and 10-2 signs of hydroxychloroquine retinopathy and showed that sequential macular thickness plots using routine Early Treatment Diabetic Retinopathy Study (ETDRS) data could identify an onset of rapid retinal thinning several years before the appearance of conventional signs of hydroxychloroquine retinopathy.…”