Abstract
Purpose :
To evaluate the effects of hydroxychloroquine (HCQ) therapy on the retina by comparing the results of functional and structural measures.
Methods :
39 patients (10-79 years of age) on HCQ had a complete ophthalmologic examination and the following recommended screening tests for HCQ retinopathy: 10-2 automated visual fields (VFs: Humphrey CZM); spectral domain optical coherence tomography volume and high resolution horizontal line scans (OCT: Spectralis Heidelberg Eng); short-wavelength fundus autofluorescence (SW-AF) and mfERGs (Diagnosys LLC). (1) For the mfERG, a scaled103 hexagon array was used and response densities of the first order kernel were analyzed by grouping the 103 responses into six concentric rings and calculating ring ratios using the R5 ring response as the “ reference ring “ and dividing by all other ring response amplitudes (R1-R6). (2) The ratios of the R5 to each of the other rings were compared to 95% CIs from control eyes.
Results :
Of the 39 patients, 23 had been treated with HCQ for ≥ 5 years with a cumulative dose > 1000g. 14 of the patients had functional damage as seen by either mfERG and/or VF abnormalities. In particular, 11 of the patients had abnormal mfERG ring ratios and 10 had abnormal VFs. A comparison of the mfERG and VF results showed that of the 11 patients with abnormal ring ratios, 7 had partial or complete ring scotomas. These were more pronounced in the superior field. Fewer eyes showed structural damage. In particular, outer retinal abnormalities on OCT were observed in 8 patients and were associated with abnormal VFs. The outer retinal abnormalities ranged from disruption of the inner/outer segment junction and cone outer segment interdigitation zone in the parafoveal region, to thinning of the outer nuclear layer to atrophy of the retinal pigment epithelium in the central macular area. They were more prevalent in the inferior retinal scans. Only 5 of the 8 patients with outer retinal abnormalities showed signs of abnormal SW-AF in the central macula.
Conclusions :
With HCQ therapy, functional deficits were more frequent than structural or morphological deficits. Also the inferior retina, in addition to the pericentral region, appeared to be more vulnerable to the toxic effects of HCQ. 1. Marmor MF et al. Ophthalmology 2016. 2. Adam MK et al. BJO 2012.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.