Toxic Effects of Hydroxychloroquine on the Choroid

Abstract

Multimodal imaging demonstrates choriocapillaris degeneration in eyes with HCQ retinopathy, particularly those with severe retinopathy. The choroidal change was associated with outer retinal toxicity of HCQ.

Outer Nuclear Layer Damage for Detection of Early Retinal Toxicity of Hydroxychloroquine

“…Although the first results of this analysis showed no relationship between the thinning of GCIPL and HCQ retinopathy [10], recent results have led other researchers to hypothesize that GCIPL thinning could be an early indicator of it in screening use [11]. However, recent studies have located HCQ damage in the outer retina or the choroidal tissue, which is close to the findings of in vitro studies [12][13][14][15]. Some of these studies assessed the retina using OCT angiography.…”

“…However, one of its main side effects is HCQ retinopathy. This finding was first described in 1959 in patients that used chloroquine [3], and since then, HCQ retinopathy has been well documented in several papers [4][5][6][7][8][9][10][11][12][13][14][15], as early detection of it and drug discontinuation prevents the patient from developing established visual symptoms [13][14][15]. It is important to point out that the discontinuation of hydroxychloroquine does not prevent further macular deterioration.…”

“…Similarly, in patients with temporal VF defect, nasal ONL thinning was significant compared with temporal, superior, or inferior ONL values (p < 0.001). 1,5,9,10,11,13, and 14 (p = 0.046, p = 0.017, p = 0.014, p = 0.003, p = 0.047, p = 0.015, p = 0.024, and p = 0.046, respectively). No sector of GCL was correlated with the duration of HCQ treatment (p > 0.211).…”

“…The average retinal layer measurement of each 8 × 8 (3 • × 3 • ) sector, which made up the 64 sectors, was settled. As HCQ toxicity is located in the center of the macula [12][13][14], only 4 × 4 central grids were analyzed to expedite the study. These 16 sectors were numbered as shown in Figure 1.…”

“…Some of these studies assessed the retina using OCT angiography. This device allowed them to obtain en face images that could be analyzed by two investigators in a masked manner [13,15]. However, OCT segmentation could depict objective values of thickness of retinal layers.…”