Macular Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer Thicknesses in Hydroxychloroquine Retinopathy.

OBJECTIVE

To investigate macular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (RNFL) thicknesses in patients with hydroxychloroquine retinopathy of differing severity.

DESIGN

Cross-sectional, case-control comparison study.

PARTICIPANTS

From patients screened for hydroxychloroquine retinopathy between January 2016 and October 2021 using swept-source optical coherence tomography (SS-OCT), fundus autofluorescence (FAF), and standard automated perimetry, 66 patients with retinopathy and 66 without retinopathy were included by 1:1 propensity score matching based on age, sex, systemic diseases, history of tamoxifen and pentosan use, and kidney disease.

METHODS

Eyes with hydroxychloroquine retinopathy were divided into early, moderate, and severe stages. Inner-retinal thickness parameters, including macular GCC (RNFL + ganglion cell layer + inner plexiform layer) and peripapillary RNFL thicknesses, were automatically obtained using SS-OCT (DRI-OCT Triton, Topcon Inc., Japan) and compared between patients with and without retinopathy and between severity subgroups. The structure-function relationships between GCC or peripapillary RNFL thicknesses and perimetric parameters including mean deviation (MD) and visual field index (VFI) of Humphrey 30-2 test were evaluated.

MAIN OUTCOME MEASURES

Macular GCC and peripapillary RNFL thickness parameters.

RESULTS

The average macular GCC and peripapillary RNFL thicknesses were significantly decreased in patients with hydroxychloroquine retinopathy relative to those without retinopathy. Macular GCC thicknesses in 4 of 6 macular sectors and peripapillary RNFL thicknesses in 9 of 12 clock-hour sectors were significantly different between the groups. The differences in the average and sectoral macular GCC parameters were statistically significant among the severity subgroups, particularly between severe and earlier stages. Average macular GCC and peripapillary RNFL thicknesses significantly correlated with MD and VFI in all patients (all P < .001).

CONCLUSIONS

Macular GCC and peripapillary RNFL thinning was more prominent in eyes with severe hydroxychloroquine retinopathy, as indicative of inner-retinal thinning in eyes with advanced-stage disease. Further, as inner-retinal thinning showed a significant correlation with worse perimetric function, cautious evaluation of the inner retina may be required for eyes with advanced hydroxychloroquine retinopathy.