Retinal damage in chloroquine maculopathy, revealed by high resolution imaging: a case report utilizing adaptive optics scanning laser ophthalmoscopy

Abstract

A 53-year-old Asian woman was treated with hydroxychloroquine and chloroquine for lupus erythematosus. Within a few years, she noticed circle-shaped shadows in her central vision. Upon examination, the patient's visual acuity was 20 / 25 in both eyes. Humphrey visual field (HVF) testing revealed a central visual defect, and fundoscopy showed a ring-shaped area of parafoveal retinal pigment epithelium depigmentation. Fundus autofluorescence imaging showed a hypofluorescent lesion consistent with bull's eye retinopathy. Adaptive optics scanning laser ophthalmoscope (AO-SLO) revealed patch cone mosaic lesions, in which cones were missing or lost. In addition, the remaining cones consisted of asymmetrical shapes and sizes that varied in brightness. Unlike previous studies employing deformable mirrors for wavefront aberration correction, our AO-SLO approach utilized dual liquid crystal on silicon spatial light modulators. Thus, by using AO-SLO, we were able to create a photographic montage consisting of high quality images. Disrupted cone AO-SLO images were matched with visual field test results and functional deficits were associated with a precise location on the montage, which allowed correlation of histological findings with functional changes determined by HVF. We also investigated whether adaptive optics imaging was more sensitive to anatomical changes compared with spectral-domain optical coherence tomography.

Keywords: Adaptive optics scanning laser ophthalmoscopy; Bull's eye maculopathy; Chloroquine maculopathy; Hydroxychloroquines; Photoreceptor.

Fig. 1

Photographs of the right (A) and left (B) eyes. Fundus autofluorescent (FAF) images of the right (C) and left (D) eyes are also shown. The FAF image shows a hypofluorescent lesion in the foveal and perifoveal areas consistent with bull's eye retinopathy. A prominent hypofluorescent lesion is visible in the left eye, indicating a marked atrophy of the retinal pigment epithelium layer. The bull's eye pattern of depigmentation is also evident on fundus photography and fundus autofluorescent images.

Fig. 2

Adaptive optics scanning laser ophthalmoscope (AO-SLO) montage (A,B) and spectral-domain optical coherence tomography (SD-OCT) (C,D) images of both eyes. The vertical SD-OCT images from both the right (A) and left (B) eyes show loss of photoreceptor inner segment/outer segment junctions (moth eaten appearance).

Fig. 3

Adaptive optics scanning laser ophthalmoscope (AO-SLO) montage from the left eye (A) matched with the corresponding red free image. Magnified AO-SLO images (B,C) are also shown. (B) shows the area indicated by the white box on the montage. For comparison, (C) shows an age-matched normal retina in the same location. As shown in (B), disruptions in the cone mosaic, where cones were missing or lost, is apparent. These disruptions were not present in the normal subject. Additionally, in (B), cones appear to be asymmetrical in shape and size with variable brightness. Scale bar in (B) and (C) = 25 µm.

Fig. 4

Correlation of structural and functional defects. Humphrey visual field (A) revealed a significant central defect. The adaptive optics scanning laser ophthalmoscope (AO-SLO) montage from the right eye (B) was matched with the infrared image. Images (C), (D), and (E) are magnified AO-SLO images of the locations of visual field defects (white boxes). Images (F), (G), and (H) are images in the same location from an age-matched normal retina. The location and cone density for each figure is shown. The AO-SLO images (C), (D), and (E), show the cone mosaic disruption and dark patchy lesions where cones are missing or lost. Image D had the lowest cone density, and was lower than observed in a normal subject (F,G,H). Cones in images (C), (D), and (E) were asymmetric in shape and size and exhibited variable brightness. Scale bar in (C), (D), and (E) = 25 µm. SR = superior retina; IR = inferior retina; NR = nasal retina.