HYDROXYCHLOROQUINE TREATMENT ALTERS RETINAL LAYERS AND CHOROID WITHOUT APPARENT TOXICITY IN OPTICAL COHERENCE TOMOGRAPHY

Optical coherence tomography angiography suggests different retinal pathologies in multiple sclerosis and Sjögren's syndrome

BACKGROUND

While retinal vessel changes are evident in the eyes of patients with relapsing-remitting multiple sclerosis (RRMS), changes in the vasculature of possible MS mimics such as primary Sjögren's syndrome (pSS) remain to be determined. We investigated the potential of retinal optical coherence tomography (OCT) angiography (OCTA) as diagnostic tool to differentiate between patients with RRMS and pSS.

METHODS

This cross-sectional study included patients with RRMS (n = 36), pSS (n = 36) and healthy controls (n = 30). Participants underwent clinical examination, assessment of visual acuity, retinal OCT, OCTA, and serum markers of glial and neuronal damage. We investigated the associations between OCTA parameters, visual functions, and serum markers. Eyes with a history of optic neuritis (ON) were excluded from analysis.

RESULTS

We observed a significant thinning of the combined ganglion cell and inner plexiform layer in the eyes of patients with RRMS but not with pSS, when compared to healthy controls. Retinal vessel densities of the superficial vascular complex (SVC) were reduced in both patients with RRMS and pSS. However, retinal vessel rarefication of the deep vascular complex (DVC) was only evident in patients with pSS but not RRMS. Using multivariate regression analysis, we found that DVC vessel loss in pSS patients was associated with worse visual acuity.

CONCLUSIONS

Compared to patients with RRMS, rarefication of deep retinal vessels is a unique characteristic of pSS and associated with worse visual function. Assuming a disease-specific retinal vessel pathology, these data are indicative of a differential affliction of the gliovascular complex in the retina of RRMS and pSS patients.

Choroidal thickness in eyes of rheumatoid arthritis patients measured using optical coherence tomography: A systematic review and meta-analysis

Rheumatoid arthritis (RA), an autoimmune disease, affects eyes in 25% of cases. Retinal alterations in RA can function as biomarkers as early risk indicators for developing sight-threatening conditions. Optical coherence tomography (OCT) provides high-resolution images of the retina and its component's thickness measures. The purpose of this review is to compare the choroidal thickness (CT) of RA patients and healthy controls. We examined the databases of PubMed, Scopus, and Embase. Depending on the heterogeneity, an appropriate model was used for the meta-analysis. Additionally, meta-regression, publication bias, subgroup analyses, and quality evaluation were carried out. We evaluated 8 studies involving 363 RA patients and 343 healthy controls. Our findings demonstrated that RA participants had significantly lower CT at 500 and 1500 µm nasal and temporal to the fovea compared to controls. The subfoveal, 1000 µm temporal and nasal to the fovea, and average CT, however, did not demonstrate statistical significance. The results of this study demonstrate that choroidal thickness is different in RA patients from healthy controls in several areas. OCT measurements may be related to both the visual acuity and the possibility of developing several rheumatic-ophthalmic problems. Future research is thus needed to get more firm findings.

Automated analysis of choroidal thickness in patients with systemic lupus erithematosus treated with hydroxychloroquine

PURPOSE

To evaluate the influence of hydroxychloroquine (HCQ) in choroidal thickness (CT) in patients with systemic lupus erythematous (SLE), considering the possible impact of disease activity on the choroid.

METHODS

Cross-sectional study comparing three groups: two groups of SLE patients treated with HCQ without HCQ-retinopathy (32 eyes/32 patients with < 5 years of HCQ (group 1) and 44 eyes/44 patients with > 5 years of HCQ (group 2)), and an age-matched healthy control group of 46 eyes/46 patients (group 3). A complete ophthalmic examination was performed, including swept-source optical coherence tomography (SS-OCT) Triton (Topcon). Data were correlated to systemic disease activity parameters.

RESULTS

CT was thicker in group 1 compared to group 3 in central, nasal, and superior sectors, and to group 2 in inner superior and outer inferior sectors (p < 0.05). In the correlation analysis, disease activity and CT were inversely correlated in most sectors (p < 0.05). In the regression analysis, HCQ was related to thinner CT in temporal and inferior sectors and disease activity with variations in nasal sectors (p < 0.05).

CONCLUSIONS

In SLE patients, HCQ is correlated to decreased CT, especially in the inferior and temporal areas. The choroid shows different responses to SLE activity and HCQ, and some sectors may be more sensitive than others.

Effects of hydroxychloroquine therapy on choroidal volume and choroidal vascularity index

PURPOSE

To determine changes in choroidal volume (CV) and choroidal vascularity index (CVI) in patients on hydroxychloroquine (HCQ) therapy.

METHODS

Retrospective analysis of patients on HCQ therapy. CV and CVI were assessed below the central foveal region on spectral-domain optical coherence tomography using an automatic denoising and localization algorithm. CV and CVI were compared with age-matched controls. Regression analyses were performed to generate associations between CV and CVI with demographics and HCQ treatment parameters. Associations were assessed using a generalized estimating equation model adjusted for intra-subject inter-eye correlations.

RESULTS

A total of 137 adult patients (23 males and 114 females) were included. Mean age was 45.6 ± 13.7 years and most patients identified as Caucasian (79%). Total duration of HCQ therapy ranged from 3 months to 20 years. Daily HCQ intake varied from 150-600 mg (mean = 304 mg), while cumulative doses ranged from 18-2,800 g. At presentation, the median CV was 0.51 (IQR:0.356-0.747) mm, and median CVI was 0.559 (IQR:0.528-0.578). Increased cumulative HCQ dose was associated with decreased CV (p = 0.006). Compared to age-matched controls, CV, CVI, and luminal area were significantly lower in the study group (p = 0.0003, 0.0001, and 0.0002).

CONCLUSION

In this study, we present a novel analysis of key biomarkers which predate the occurrence of HCQ retinopathy. Choroidal volume and vascularity index are significantly reduced in patients on HCQ therapy, especially at higher cumulative doses. These findings suggest new tools to guide medical decision-making for patients receiving HCQ therapy for rheumatologic diseases.

Review of Retinal Imaging Modalities for Hydroxychloroquine Retinopathy

This review provides an overview of conventional and novel retinal imaging modalities for hydroxychloroquine (HCQ) retinopathy. HCQ retinopathy is a form of toxic retinopathy resulting from HCQ use for a variety of autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Each imaging modality detects a different aspect of HCQ retinopathy and shows a unique complement of structural changes. Conventionally, spectral-domain optical coherence tomography (SD-OCT), which shows loss or attenuation of the outer retina and/or retinal pigment epithelium-Bruch's membrane complex, and fundus autofluorescence (FAF), which shows parafoveal or pericentral abnormalities, are used to assess HCQ retinopathy. Additionally, several variations of OCT (retinal and choroidal thickness measurements, choroidal vascularity index, widefield OCT, en face imaging, minimum intensity analysis, and artificial intelligence techniques) and FAF techniques (quantitative FAF, near-infrared FAF, fluorescence lifetime imaging ophthalmoscopy, and widefield FAF) have been applied to assess HCQ retinopathy. Other novel retinal imaging techniques that are being studied for early detection of HCQ retinopathy include OCT angiography, multicolour imaging, adaptive optics, and retromode imaging, although further testing is required for validation.