Pericentral Retinopathy and Racial Differences in Hydroxychloroquine Toxicity

High-dose hydroxychloroquine induces changes in low-frequency brain oscillations in electrocorticographic records not concurrent with alterations in cardiac, hepatic, and renal function in wistar rats

The toxicity of hydroxychloroquine (HCQ) can impact the function of vital organs, leading to ocular and cardiovascular damage. This study aims to evaluate the toxicity of HCQ through electrocorticographic evaluation and blood biochemical parameters in Wistar rats. The animals received a dose of HCQ of 350 mg/kg via gavage every 12 hours for periods of 24, 48, 72 and 96 hours, with each group consisting of n = 9. After treatment, the animals underwent surgery to implant electrodes in the motor cortex region and subsequently underwent bipolar electrocorticography. The electrodes for acquiring electrocardiographic recordings were fixed in the D II position and blood samples were analyzed for liver and kidney function. The results demonstrated that high doses of HCQ altered electrocorticographic features, decreased cardiac activity throughout treatment, and significantly elevated aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. However, assessment of renal function, as indicated by serum creatinine levels, revealed no significant changes. These results suggest that exposure to high doses of HCQ in rats may disrupt the structures and functions of vital organs.

Guidelines for the Diagnosis, Management, and Study of Autoimmune Retinopathy from the American Academy of Ophthalmology's Task Force

PURPOSE

The American Academy of Ophthalmology created a task force to advance the understanding of autoimmune retinopathy (AIR) and provide guidelines on the diagnosis and management of this complex disorder.

DESIGN

A search on PubMed and Google Scholar of English-language studies was conducted without date restrictions. The Task Force reviewed the current literature and formulated an expert consensus on the management of AIR as well as recommendations for future efforts to improve our understanding of this condition.

RESULTS

Key clinical and imaging features are discussed, and a new diagnostic framework is proposed based on likelihood of AIR (probable AIR, possible AIR, and unlikely AIR) to provide a more standardized approach for categorizing disease. Patients who possess all the following features can be categorized as having probable AIR: (1) signs of disease progression based on subjective symptoms and objective testing within six months, (2) examination with less than 1+ anterior chamber or vitreous cell/haze, (3) optical coherence tomography (OCT) with outer retinal disruption and loss of the external limiting membrane/outer retinal bands/ellipsoid zone often relatively sparing the fovea, (4) characteristic fundus autofluorescence (FAF) abnormalities, (5) full field ERG with reduction of both rod and cone responses, and (6) positive anti-retinal antibodies. Those with some but not all of these features, or with otherwise atypical presentations, can be classified as possible AIR. Features that would make AIR unlikely and should elicit strong suspicion for alternative diagnoses are: (1) slowly progressive symptoms or changes on testing taking place over years, (2) retinal examination with bone spicules, retinal vascular sheathing, or retinal hemorrhages, (3) examination with more than 1+ anterior chamber or vitreous cell/haze, (4) OCT changes predominantly at the level of the RPE or areas of focal/sharply delineated outer retinal/RPE atrophy, (5) fluorescein angiography with diffuse retinal vasculitis or large areas of non-perfusion, or (6) a normal full-field electroretinogram (even with an abnormal multifocal electroretinogram).

CONCLUSIONS

These criteria will allow for better classification of patients reported in the literature and improve communication between clinicians. Further study is necessary to optimize the approach for managing AIR and will require collaborative multi-center efforts.

Cost-effectiveness of hydroxychloroquine retinopathy screening: the current guideline versus no screening and reduced regimens

OBJECTIVE

Hydroxychloroquine (HCQ) effectively treats autoimmune diseases but prolonged use may lead to retinopathy and subsequent vision loss. Guidelines suggest annual follow-up after 5 years for low-risk and 1 year for high-risk patients. This study evaluates the cost-effectiveness of current screening guidelines and a reduced regimen in the Netherlands from a societal perspective.

METHODS

A Markov model assessed costs and quality-adjusted life-years (QALYs) for current and reduced screening regimens. The model included 359 HCQ-treated patients from Radboud University Medical Center. Cost-effectiveness was examined in the general population and patients using < 5.0 mg/kg, 5.0-6.0 mg/kg, or > 6.0 mg/kg HCQ per day for several reduced regimens.

RESULTS

Compared to no screening, the current screening guideline saves costs (i.e., €210 per patient), while gaining QALYs (i.e., 0.79 QALY per patient) over a lifetime in the Netherlands. However, in patients receiving < 5.0 mg/kg HCQ per day, a biennial screening regimen after 10 years using SD-OCT was more cost-effective. For those with 5.0-6.0 mg/kg and > 6.0 mg/kg per day, initiating annual screening with an SD-OCT after 5 years was more cost-effective than the current guideline.

CONCLUSIONS

Screening for HCQ retinopathy is cost-effective, but delayed initiation and a reduced frequency, using solely an SD-OCT, are more cost-effective. We recommend screening with an SD-OCT and a biennial regimen after 10 years for low-risk patients, an annual regimen after 5 years for intermediate- and high-risk patients.

HYDROXYCHLOROQUINE CAN BE RESUMED WITH CLOSE MONITORING AFTER RETINOPATHY HAS DEVELOPED, WITHOUT MAJOR VISUAL LOSS: CASE REPORT

PURPOSE

The aim of this study was to present a patient with systemic lupus erythematosus on longstanding hydroxychloroquine (HCQ) use for whom HCQ was stopped because of signs of toxicity and then resumed four years later because of dire systemic need.

METHODS

This is a long-term retrospective study. Humphrey visual fields (10-2 and 24-2), fundus autofluorescence imaging, and spectral domain optical coherence tomography (OCT) were used to follow progression over time.

RESULTS

The patient was on HCQ for 26 years, with a cumulative dose over 3,000 g. HCQ was stopped in 2011 because of macular toxicity. She remained off HCQ for four years, during which time she developed type 1 diabetes due to an immunologic attack on the pancreas and then JC (John Cunningham) viremia after a period of treatment with mycophenolate, which put her at risk for progressive multifocal leukoencephalopathy. Mycophenolate was discontinued, and HCQ was resumed with careful follow-up over the next 7 years. The toxic maculopathy showed only mild slow progression since HCQ was resumed.

CONCLUSION

Careful annual monitoring using Humphrey visual field 10-2 and spectral domain OCT imaging remains the standard of care for the patients on HCQ. However, it may be possible with close monitoring when there is compelling systemic need to resume HCQ after it has been stopped, with only slow progression of the retinopathy. This allowed the patient to have an improved quality of life and reduced the risk of severe morbidity and mortality.

Acupuncture Combined with Periocular Injection for Treatment of Hydroxychloroquine Retinopathy with Cystoid Macular Edema: A Case Report

CONCLUSION

For HCQ retinopathy with CME, acupuncture combined with periocular injection can be used to improve the CME and protect the central vision. Subsequent research endeavors involving a more extensive cohort and extended observation periods are warranted to evaluate the effectiveness and safety profile of the intervention.

Artificial intelligence for detection of retinal toxicity in chloroquine and hydroxychloroquine therapy using multifocal electroretinogram waveforms

Chloroquine and hydroxychloroquine, while effective in rheumatology, pose risks of retinal toxicity, necessitating regular screening to prevent visual disability. The gold standard for screening includes retinal imaging and automated perimetry, with multifocal electroretinography (mfERG) being a recognized but less accessible method. This study explores the efficacy of Artificial Intelligence (AI) algorithms for detecting retinal damage in patients undergoing (hydroxy-)chloroquine therapy. We analyze the mfERG data, comparing the performance of AI models that utilize raw mfERG time-series signals against models using conventional waveform parameters. Our classification models aimed to identify maculopathy, and regression models were developed to predict perimetric sensitivity. The findings reveal that while regression models were more adept at predicting non-disease-related variation, AI-based models, particularly those utilizing full mfERG traces, demonstrated superior predictive power for disease-related changes compared to linear models. This indicates a significant potential to improve diagnostic capabilities, although the unbalanced nature of the dataset may limit some applications.

Optical coherence tomography characteristics in hydroxychloroquine retinopathy and the correlations with visual deterioration in Taiwanese

PURPOSE

This study aimed to investigate optical coherence tomography (OCT) characteristics in hydroxychloroquine (HCQ) retinopathy and their correlation with visual acuity among Taiwanese patients.

MATERIALS AND METHODS

We retrospectively recruited patients undergoing long-term HCQ treatment who had received examinations of best-corrected visual acuity and OCT scans. We observed disruptions in the ellipsoid zone (EZ) and retinal pigment epithelium (RPE) across different retinal regions. Principal component analysis (PCA) was employed to identify the most significant factors associated with visual deterioration.

RESULTS

Among the 120 eyes included in the study, HCQ retinopathy was present in 42 eyes (35.0%). In patients with mild-to-moderate retinopathy, the pericentral pattern was predominant (75.0%), whereas no parafoveal pattern was observed. Serial examinations revealed that lesions typically progressed from pericentral to parafoveal and foveal regions. EZ disruption was observed in all affected cases, most frequently at the pericentral region (100%), followed by the perifoveal (87.4%), parafoveal (72.1%), and foveal (43.2%) regions. RPE disruption was noted in 59.5% of cases, with the highest prevalence at the pericentral (53.2%) and perifoveal (52.3%) regions, followed by the parafoveal (33.3%) and foveal (28.8%) regions. PCA identified RPE disruption at the fovea and parafoveal regions as the most strongly correlated factors for visual deterioration.

CONCLUSIONS

In Taiwanese patients, HCQ retinopathy predominantly manifests with pericentral lesions, while isolated parafoveal lesions are rare as an initial presentation. RPE disruption, rather than EZ disruption, appears to be the primary determinant for visual deterioration in this population.

Target in Sight: A Comprehensive Review of Hydroxychloroquine-Induced Bull's Eye Maculopathy

Purpose of Review

We review the latest screening and diagnostic techniques, and the most recent recommendations on the management of hydroxychloroquine retinopathy.

Recent Findings

Hydroxychloroquine (HCQ) has been shown to cause retinal toxicity in a dose-dependent fashion. Early diagnosis is critical as the resultant retinopathy is not reversible. New imaging modalities, such as adaptive optics (AO), microperimetry, and retro-mode imaging, may show promise in the timely diagnosis of HCQ retinopathy.

Summary

Automated visual fields and spectral-domain optical coherence tomography (SD-OCT) are the primary tests used in routine screening for HCQ retinopathy, but fundus autofluorescence (FAF) and multifocal electroretinogram (mfERG) have also been shown to be useful. A baseline ophthalmologic examination is recommended in all patients beginning long-term hydroxychloroquine therapy within the first year of starting therapy. Automated visual fields and SD-OCT should be included during this baseline exam in patients with pre-existing macular conditions. Afterwards, annual screening can be deferred for the first 5 years of HCQ treatment unless the patient has a major risk factor.

Classification of Hydroxychloroquine Retinopathy: A Literature Review and Proposal for Revision

Establishing universal standards for the nomenclature and classification of hydroxychloroquine retinopathy is essential. This review summarizes the classifications used for categorizing the patterns of hydroxychloroquine retinopathy and grading its severity in the literature, highlighting the limitations of these classifications based on recent findings. To overcome these limitations, I propose categorizing hydroxychloroquine retinopathy into four categories based on optical coherence tomography (OCT) findings: parafoveal (parafoveal damage only), pericentral (pericentral damage only), combined parafoveal and pericentral (both parafoveal and pericentral damage), and posterior polar (widespread damage over parafoveal, pericentral, and more peripheral areas), with or without foveal involvement. Alternatively, eyes can be categorized simply into parafoveal and pericentral retinopathy based on the most dominant area of damage, rather than the topographic distribution of overall retinal damage. Furthermore, I suggest a five-stage modified version of the current three-stage grading system of disease severity based on fundus autofluorescence (FAF) as follows: 0, no hyperautofluorescence (normal); 1, localized parafoveal or pericentral hyperautofluorescence on FAF; 2, hyperautofluorescence extending greater than 180° around the fovea; 3, combined retinal pigment epithelium (RPE) defects (hypoautofluorescence on FAF) without foveal involvement; and 4, fovea-involving hypoautofluorescence. These classification systems can better address the topographic characteristics of hydroxychloroquine retinopathy using disease patterns and assess the risk of vision-threatening retinopathy by stage, particularly with foveal involvement.

SCREENING PRACTICES AND LATE DIAGNOSIS OF HYDROXYCHLOROQUINE RETINOPATHY IN ASIAN PATIENTS

PURPOSE

To investigate the associations between screening practices and late diagnosis in Asian patients with hydroxychloroquine retinopathy.

METHODS

In total, 92 Korean patients with hydroxychloroquine retinopathy were included and separated into late diagnosis and earlier diagnosis groups according to the retinopathy stage at the time of diagnosis. Details of screening practices regarding timing and modalities for baseline and annual monitoring examinations were compared between the two groups. Adherence to the current American Academy of Ophthalmology guidelines was compared between the two groups.

RESULTS

Timing of baseline and initial monitoring examinations was appropriate as per the Academy of Ophthalmology guidelines in only 5.3% of patients with late diagnosis. There were significant differences in the proportions of patients receiving initial monitoring at 5 years of use and those receiving annual monitoring between the late and earlier diagnosis groups ( P = 0.003 and <0.001, respectively). The duration from the start date of hydroxychloroquine therapy to the first monitoring examination was significantly prolonged in the late diagnosis group ( P < 0.001). Multivariate logistic regression revealed significant association of the time duration with the first monitoring examination ( P = 0.042) and age ( P = 0.028) with late diagnosis.

CONCLUSION

Results of this study suggest that poor adherence to the Academy of Ophthalmology guideline, particularly delayed initial monitoring, may be associated with late diagnosis of hydroxychloroquine retinopathy.

Exome sequencing and genome-wide association analyses unveils the genetic predisposition in hydroxychloroquine retinopathy

OBJECTIVES

To unveil the candidate susceptibility genes in chloroquine/hydroxychloroquine (CQ/HCQ) retinopathy using whole exome sequencing (WES) and genome-wide association study (GWAS).

METHODS

Patients with a diagnosis of CQ/HCQ retinopathy based on the comprehensive demographic and ocular examination were included. The peripheral blood was extracted for WES and GWAS analyses. The Chinese Han Southern database from 1000 genomes was used as control group to compare the affected percentage. Multivariate logistic regression analysis adjusted for age, HCQ dose, duration and renal disease were used to analyze the correlation between genetic variants and visual outcome. A poor vision outcome was defined as visual acuity <6/12. An abnormal anatomical outcome was defined as disruption of ellipsoid zone in the fovea.

RESULTS

Twenty-nine patients with an average age of 60.9 ± 13.4 years, treatment duration of 12.1 ± 6.2 years, daily dose of 8.5 ± 4.1 mg/kg, and the cumulative dose of 1637.5 ± 772.5 g, were genotyped. Several candidate genes associated with CQ/HCQ retinopathy were found, including RP1L1, RPGR and RPE65, with a difference of affected percentage over 50% in mutation between the case and control groups. New foci in CCDC66: rs56616026 (OR = 63.43, p = 1.63 × 10-8) and rs56616023 (OR = 104.7, p = 5.02 × 10-10) were identified significantly associated with HCQ retinopathy. Multivariate analysis revealed increased genetic variants were significantly associated with poor functional (OR = 1.600, p = 0.004) and structural outcome (OR = 1.318, p = 0.043).

CONCLUSIONS

Several candidate susceptibility genes including RP1L1, RPGR, RPE65 and CCDC66 were identified to be associated with CQ/HCQ retinopathy. In addition to disease susceptibility, patients with increased genetic variants are more vulnerable to poor visual outcomes.

Atypical Presentations of Hydroxychloroquine Retinopathy: A Case Series Study

Background/Objective: Hydroxychloroquine retinopathy, traditionally characterized by parafoveal or pericentral outer retinal damage, is explored for atypical presentations in Asian patients. This challenges conventional beliefs regarding onset, retinopathy pattern, and associated visual field defects. Methods: Ninety-five patients diagnosed with hydroxychloroquine retinopathy at Hanyang University Hospital underwent screening from January 2010 to December 2023. Swept-source optical coherence tomography (SS-OCT), ultra-widefield fundus autofluorescence (UWF-FAF), and automated visual fields (VF) were employed for detailed structural and functional evaluations. Multifocal electroretinography was performed in selected cases requiring additional objective evidence of retinal toxicity. Results: Among 95 patients, 14 (14.7%) exhibited atypical presentations, including very early onset (n = 1), (far) peripheral-dominant damages (n = 4), perivascular involvement (n = 1), bitemporal hemianopsia due to nasal extensive lesions (n = 1), unilateral involvement (n = 2), and asymmetric involvement in retinopathy pattern or severity between the eyes (n = 7). These findings underscore the importance of utilizing expanded imaging techniques, such as ultra-widefield FAF imaging, to identify atypical presentations of retinal involvement. Conclusions: Screening physicians should consider these atypical presentations to ensure timely diagnosis and appropriate management in patients undergoing hydroxychloroquine treatment.

Skin and ophthalmic complications of chloroquine and hydroxychloroquine in patients with rheumatoid arthritis and systemic lupus erythematous

Immunosuppressive agents are routinely used to control autoimmunity. However, some adverse events are correlated to their clinical applications. The aim of this study was to study the clinical findings and ocular and cutaneous side effects of chloroquine (CQ) and hydroxychloroquine (HCQ), as current immunomodulators, in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). This descriptive study was performed on 360 individuals referred to the Rheumatology clinic during 2003-2020. Demographic characteristics and other information were collected from patients with RA and SLE. Skin and ocular complications were evaluated in patients who were on treatment with CQ and HCQ. Study populations consisted of 199 subjects with RA and 161 cases with SLE. The frequencies of skin and ocular complications in all patients treated with CQ and HCQ were 32 (17.65%) and 94 (51.9%), respectively. The prevalence of skin complications in patients with RA and SLE was 20 (10.05%) and 22 (13.66%), respectively. The frequencies of ocular complications in patients with RA and SLE were, respectively, 58 (29.4%) and 36 (22.5%). Multiple logistic regression analysis revealed that ophthalmic complications of CQ and HCQ in all patients were dependent on the effects of the duration of drug uses, disease duration, and cumulative doses (p < 0.05), unlike skin complications. Disease types had no effect on ocular complications. Based on these findings, treatment with CQ and HCQ participates in some skin and ocular complications in patients with RA and SLE which are largely associated with the duration of disease and treatment.

Risk Factors for Hydroxychloroquine Retinopathy and Its Subtypes

Importance

The major toxic effect of hydroxychloroquine is retinopathy. Thus, current guidelines recommend limiting the dose and screening annually for retinopathy among all long-term users, but individual patient factors may be associated with retinopathy risk.

Objective

To identify risk factors beyond hydroxychloroquine dose and duration of use for hydroxychloroquine retinopathy.

Design, Setting, and Participants

This cohort study of 4677 patients in the Kaiser Permanente Northern California integrated health network who initiated hydroxychloroquine, continued treatment, and underwent retinopathy screening after 5 years of use was conducted from July 1, 1997, to December 31, 2020, with up to 15 years of follow-up. Statistical analysis was performed in August 2023.

Exposure

Candidate risk factors included age at hydroxychloroquine initiation, sex, race and ethnicity, indications, chronic kidney disease (CKD), liver disease, diabetes, tamoxifen use, and medications that interact with hydroxychloroquine metabolism. Hydroxychloroquine dose was assessed from pharmacy dispensing records.

Main Outcome and Measures

Incident hydroxychloroquine retinopathy was adjudicated from masked review of guideline-recommended screening studies and classified as parafoveal or pericentral pattern. Multivariable Cox proportional hazards regression was used to assess potential risk factors for hydroxychloroquine retinopathy within 15 years of initiation.

Results

Of 4677 long-term hydroxychloroquine users (mean [SD] age at initiation, 52.4 [14.1] years; 3877 women [82.9%]), 125 patients developed hydroxychloroquine retinopathy within 15 years (102 parafoveal, 23 pericentral). Older age at time of hydroxychloroquine initiation was associated with retinopathy risk, with adjusted hazard ratios (HRs) of 2.48 (95% CI, 1.28-4.78) for those aged 45 to 54 years, 3.82 (95% CI, 2.05-7.14) for those aged 55 to 64 years, and 5.68 (95% CI, 2.99-10.79) for those aged 65 years or older compared with those younger than 45 years. The risk of retinopathy was higher among females than males (HR, 3.83 [95% CI, 1.86-7.89]), among patients with CKD stage 3 or greater (HR, 1.95 [95% CI, 1.25-3.04]), and among individuals with tamoxifen use (HR, 3.43 [95% CI, 1.08-10.89]). The likelihood of pericentral retinopathy was higher among Asian patients (HR, 15.02 [95% CI, 4.82-46.87]) and Black patients (HR, 5.51 [95% CI, 1.22-24.97]) compared with non-Hispanic White patients.

Conclusions and Relevance

This study suggests that increasing age, female sex, CKD stage 3 or greater, and tamoxifen use were associated with a higher risk of hydroxychloroquine retinopathy, whereas being younger than 45 years at hydroxychloroquine initiation and male sex were associated with a lower risk. Race and ethnicity were also associated with the pattern of retinopathy. These factors should be incorporated into hydroxychloroquine dosing decisions.

Demographic and clinical characteristics associated with screening practices for hydroxychloroquine retinopathy

In this nationwide population-based cohort study, we investigated the demographic and clinical characteristics associated with hydroxychloroquine retinopathy screening using the National Health Insurance Review and Assessment database in South Korea. This study included a total of 32,732 at-risk patients, identified based on having been prescribed hydroxychloroquine for at least 6 months, and 15,477 long-term (> 5 years) users between January 2010 and December 2020. Participants were categorized based on the performance of baseline examinations (within 1 year of hydroxychloroquine use) and monitoring examinations (after 5 years of hydroxychloroquine use). Demographic and clinical factors, including hospitals and medical specialties prescribing hydroxychloroquine, indications for hydroxychloroquine use, and prescription details, were compared between groups. Significant differences were found in sex, residence, departments and hospitals (primary vs. referral centers) where hydroxychloroquine was prescribed, diagnosis for hydroxychloroquine therapy, and mean daily dose between patients who did and did not undergo baseline or monitoring examinations (all P < 0.01). Patients who received hydroxychloroquine prescriptions from referral hospitals were more likely to undergo baseline and monitoring examinations compared to those from primary clinics (both P < 0.001). Additionally, patients who received hydroxychloroquine prescriptions from the rheumatology department and had systemic lupus erythematosus were more likely to undergo baseline and monitoring examinations compared to other patients (all P < 0.001). There were notable differences in the number of modalities used for retinopathy screening between primary and referral centers (P < 0.001). Our findings suggest that several clinical factors related to hydroxychloroquine prescription and screening centers are associated with retinopathy screening practices.

Causes and trends of late diagnosis in Korean patients with hydroxychloroquine retinopathy

Introduction

Late diagnosis of hydroxychloroquine retinopathy remains a major concern, with the potential for irreversible visual impairment. This study aimed to investigate the causes of late diagnosis in a hospital-based cohort of Korean patients with hydroxychloroquine retinopathy and assess the trend of late diagnosis from 2015 to 2022.

Methods

Thirty-eight patients with a late diagnosis (severe stage at diagnosis) among 94 patients with hydroxychloroquine retinopathy were included in the analysis. The causes of late diagnosis were categorized as referral-related, patient-related, and screening-related factors.

Results

The most prevalent cause was no or late referral to ophthalmologists, contributing to a significant gap in timely identification. Patient-related causes included delayed monitoring visits despite scheduled appointments and early-onset disease. Screening-related causes encompassed an insufficient number of sensitive tests, leading to inadequate evidence for diagnosis, and missed or wrong diagnoses by screening physicians. The proportion of late diagnoses decreased over time, indicating improvements in overall screening and detection. The decreasing proportions of screening-related causes suggest advancements in screening practices and the use of multiple sensitive tests for screening.

Discussion

Efforts to further reduce late diagnoses and improve screening and diagnostic processes are necessary. Our data emphasize the importance of timely referral to ophthalmologists for early detection and management.

Implementation of a pilot teleretinal screening protocol for hydroxychloroquine retinopathy in a Los Angeles County safety net clinic

INTRODUCTION

This study aimed to determine whether teleretinal screening for hydroxychloroquine retinopathy (HCQR) improves clinical efficiency and adherence to recommended screening guidelines compared to face-to-face screening among patients in a large safety net medical system.

METHODS

In this retrospective cohort study of a consecutive sample of 590 adult patients with active HCQ prescriptions seen in the outpatient ophthalmology clinic at Los Angeles County + University of Southern California Medical Center from 1 September 2018 to 25 November 2019, 203 patients underwent technician-only tele-HCQR screening (THRS), and 387 patients underwent screening with traditional face-to-face visits (F2FV) with an eye-care provider. Data on clinic efficiency measures (appointment wait time and encounter duration) and adherence to recommended screening guidelines were collected and compared between the two cohorts.

RESULTS

Compared to F2FV, the THRS cohort experienced significantly shorter median (interquartile range) time to appointment (2.5 (1.5-4.6) vs. 5.1 (2.9-8.4) months; p < 0.0001), shorter median encounter duration (1 (0.8-1.4) vs. 3.7 (2.5-5.2) hours; p < 0.0001) and higher proportion of complete baseline screening (102/104 (98.1%) vs. 68/141 (48.2%); p < 0.001) and complete chronic screening (98/99 (99%) vs. 144/246 (58.5%); p < 0.001).

DISCUSSION

A pilot THRS protocol was successfully implemented at a major safety net eye clinic in Los Angeles County, resulting in a 50.9% reduction in wait times for screening, 72.9% reduction in encounter duration and 49.9% and 40.5% increases in proportions of complete baseline and chronic screening, respectively. Tele-HCQ retinal screening protocols may improve timeliness to care and screening adherence for HCQR in the safety net setting.

Novel Therapeutics for Malaria

Malaria is a potentially fatal disease caused by protozoan parasites of the genus Plasmodium. It is responsible for significant morbidity and mortality in endemic countries of the tropical and subtropical world, particularly in Africa, Southeast Asia, and South America. It is estimated that 247 million malaria cases and 619,000 deaths occurred in 2021 alone. The World Health Organization's (WHO) global initiative aims to reduce the burden of disease but has been massively challenged by the emergence of parasitic strains resistant to traditional and emerging antimalarial therapy. Therefore, development of new antimalarial drugs with novel mechanisms of action that overcome resistance in a safe and efficacious manner is urgently needed. Based on the evolving understanding of the physiology of Plasmodium, identification of potential targets for drug intervention has been made in recent years, resulting in more than 10 unique potential anti-malaria drugs added to the pipeline for clinical development. This review article will focus on current therapies as well as novel targets and therapeutics against malaria.

Hydroxychloroquine-induced Retinal Toxicity

Long-term use of hydroxychloroquine can cause retinopathy, which may result in severe and progressive visual loss. In the past decade, hydroxychloroquine use has markedly increased and modern retinal imaging techniques have enabled the detection of early, pre-symptomatic disease. As a consequence, the prevalence of retinal toxicity in long-term hydroxychloroquine users is known to be higher than was previously estimated. The pathophysiology of the retinopathy is incompletely characterised, although significant advances have been made in understanding the disease from clinical imaging studies. Hydroxychloroquine retinopathy elicits sufficient public health concern to justify the implementation of retinopathy screening programs for patients at risk. Here, we describe the historical background of hydroxychloroquine retinopathy and summarize its current understanding. We review the utility and limitations of each of the mainstream diagnostic tests used to detect hydroxychloroquine retinopathy. The key considerations towards a consensus on the definition of hydroxychloroquine retinopathy are outlined in the context of what is known of the natural history of the disease. We compare the current screening recommendations for hydroxychloroquine retinopathy, identifying where additional evidence is required, and the management of proven cases of toxicity. Finally, we highlight the areas for further investigation, which may further reduce the risk of visual loss in hydroxychloroquine users.

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.

Practice Patterns of Screening for Hydroxychloroquine Retinopathy in South Korea

Importance

Practice patterns of hydroxychloroquine retinopathy screening have not yet been reported at a national level in South Korea.

Objective

To investigate the practice patterns of timing and modality for hydroxychloroquine retinopathy screening in South Korea.

Design, Setting, and Participants

This nationwide population-based cohort study of patients in South Korea used data from the national Health Insurance Review and Assessment database. Patients at risk were identified as those who had initiated hydroxychloroquine therapy between January 1, 2009, and December 31, 2020, and used it for 6 months or more. Patients were excluded if they underwent any of the 4 screening modalities recommended by the American Academy of Ophthalmology (AAO) for other ophthalmic diseases prior to hydroxychloroquine use. The timing and modalities of screening used in baseline and monitoring examinations were assessed between January 1, 2015, and December 31, 2021, among patients at risk and long-term (≥5 years) users.

Exposure

Adherence of baseline screening practices to the 2016 AAO recommendations (fundus examination within 1 year of drug use) was evaluated; adherence of monitoring examinations in year 5 was classified as appropriate (≥2 tests recommended by the AAO), unscreened (no test performed), and underscreened (insufficient number of tests).

Main Outcomes and Measures

Timing of screening and modalities used at baseline and monitoring examinations.

Results

A total of 65 406 patients at risk (mean [SD] age, 53.0 [15.5] years; 50 622 women [77.4%]) were included; 29 776 patients were long-term users (mean [SD] age, 50.1 [14.7] years; 24 898 women [83.6%]). Baseline screening was performed for 20.8% of the patients within 1 year, with a gradual increase from 16.6% in 2015 to 25.6% in 2021. Monitoring examinations, mostly using optical coherence tomography and/or visual field tests, were performed for only 13.5% of the long-term users in year 5 and for 31.6% of the long-term users after 5 years. Appropriate monitoring was performed for less than 10% of long-term users each year from 2015 to 2021; however, the percentage gradually increased over time. The percentage of patients undergoing any monitoring examination in year 5 was 2.3 times greater for those who had received baseline screening than for those who did not (27.4% vs 11.9%; P < .001).

Conclusions and Relevance

This study suggests there is an improving trend in retinopathy screening among hydroxychloroquine users in South Korea; however, most long-term users remained unscreened after 5 years of use. Baseline screening may be useful in reducing the number of unscreened long-term users.

Outcomes of screening for hydroxychloroquine retinopathy at the Manchester Royal Eye Hospital: 2 years' audit

BACKGROUND

The Royal College of Ophthalmologists has produced guidelines for screening for hydroxychloroquine retinopathy. New imaging modalities had suggested an increased prevalence of retinopathy compared with previous reports. The aim of this study is to identify the real-life prevalence of hydroxychloroquine retinopathy in patients attending Manchester Royal Eye Hospital screening service over a 2-year period using The RCOphth diagnostic criteria.

METHODS

Data were collected prospectively from all patients attending Manchester Royal Eye Hospital hydroxychloroquine screening service over the audit period. Results of Humphrey visual field tests, spectral-domain optical coherence tomography and fundus autofluorescence were collected as well as data on dose, indication, duration of treatment, and additional risk factors. Cases were identified as having definite, possible, or no retinopathy based on the 2018 RCOphth criteria. The data are not publicly available due to information that could compromise research participant privacy and confidentiality but are available upon request from the corresponding author.

RESULTS

910 patients attended for screening. 566 were identified as being at risk of retinopathy (543 had been on treatment >5 years, 10 had renal impairment, 12 were on doses of >5 mg/kg/day, and one was concurrently on tamoxifen). The prevalence of HCQ retinopathy was 10/910 (1.09%) of all those screened, and 1.76% of those at risk (10/566). Six patients of those deemed at risk were identified as having definite hydroxychloroquine retinopathy, while four had possible retinopathy.

CONCLUSIONS

Our results show a prevalence of retinopathy largely consistent with reports from regional audits yet reveal a far lower estimate compared to previously reported figures.

How toxic is an old friend? A review of the safety of hydroxychloroquine in clinical practice

Hydroxychloroquine (HCQ) and its close relative chloroquine (CQ) were initially used as antimalarial agents but are now widely prescribed in rheumatology, dermatology and immunology for the management of autoimmune diseases. HCQ is considered to have a better long-term safety profile than CQ and is therefore more commonly used. HCQ has a key role in the treatment of connective tissue diseases including systemic lupus erythematosus (SLE), where it provides beneficial immunomodulation without clinically significant immunosuppression. HCQ can also assist in managing inflammatory arthritis, including rheumatoid arthritis (RA). Debate around toxicity of HCQ in COVID-19 has challenged those who regularly prescribe HCQ to discuss its potential toxicities. Accordingly, we have reviewed the adverse effect profile of HCQ to provide guidance about this therapeutic agent in clinical practice.

Hydroxychloroquine Dose and Risk for Incident Retinopathy : A Cohort Study

BACKGROUND

Hydroxychloroquine is recommended for all patients with systemic lupus erythematosus and is often used for other inflammatory conditions, but a critical long-term adverse effect is vision-threatening retinopathy.

OBJECTIVE

To characterize the long-term risk for incident hydroxychloroquine retinopathy and examine the degree to which average hydroxychloroquine dose within the first 5 years of treatment predicts this risk.

DESIGN

Cohort study.

SETTING

U.S. integrated health network.

PARTICIPANTS

All patients aged 18 years or older who received hydroxychloroquine for 5 or more years between 2004 and 2020 and had guideline-recommended serial retinopathy screening.

MEASUREMENTS

Hydroxychloroquine dose was assessed from pharmacy dispensing records. Incident hydroxychloroquine retinopathy was assessed by central adjudication of spectral domain optical coherence tomography with severity assessment (mild, moderate, or severe). Risk for hydroxychloroquine retinopathy was estimated over 15 years of use according to hydroxychloroquine weight-based dose (>6, 5 to 6, or ≤5 mg/kg per day) using the Kaplan-Meier estimator.

RESULTS

Among 3325 patients in the primary study population, 81 developed hydroxychloroquine retinopathy (56 mild, 17 moderate, and 8 severe), with overall cumulative incidences of 2.5% and 8.6% at 10 and 15 years, respectively. The cumulative incidences of retinopathy at 15 years were 21.6% for higher than 6 mg/kg per day, 11.4% for 5 to 6 mg/kg per day, and 2.7% for 5 mg/kg per day or lower. The corresponding risks for moderate to severe retinopathy at 15 years were 5.9%, 2.4%, and 1.1%, respectively.

LIMITATION

Possible misclassifications of dose due to nonadherence to filled prescriptions.

CONCLUSION

In this large, contemporary cohort with active surveillance retinopathy screening, the overall risk for hydroxychloroquine retinopathy was 8.6% after 15 years, and most cases were mild. Higher hydroxychloroquine dose was associated with progressively greater risk for incident retinopathy.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Characteristics and Potential Risk Factors of Hydroxychloroquine Retinopathy in Patients with Systemic Lupus Erythematosus: Focusing on Asian Population

Purpose: Hydroxychloroquine (HCQ) would cause irreversible retinal damage, despite its pivotal role in treatment of systemic lupus erythematosus (SLE). This study aims to reassess the characteristics and risk factors of HCQ retinopathy. Methods: This study included patients with SLE who had used HCQ for >5 years and received ophthalmologic examinations during November 2017 to December 2020 in a tertiary hospital in Taiwan. Spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) were performed in all patients. Visual field assessment and/or multifocal electroretinography were done if suspicious findings were noted by SD-OCT or FAF. Clinical features and dosing details of HCQ were recorded by chart review. Results: Ninety-two patients were included, with the median duration of drug exposure of 11.2 years [interquartile range (IQR) 9.4-12.7 years], median daily dose of 6.9 mg/kg (IQR 6.1-7.7 mg/kg), and cumulative dose of 1,503.6 g (IQR 1,257.7-1,805.9 g). HCQ retinopathy was diagnosed in 10.9% of patients (10 of 92), and in 20.8% of patients (5 of 24) who complained about blurred vision. High myopia [odds ratio (OR) 5.03; 95% confidence interval (CI) 1.29-24.79; P = 0.03] and lower body weight (OR 0.88; 95% CI 0.78-0.97; P = 0.03) were significantly associated with HCQ retinopathy. Conclusions: Long-term HCQ users may suffer from retinal toxicity. Since there is no optimal substitute for HCQ, careful retinal evaluation is needed to avoid unnecessary drug discontinuation. In addition, an association between high myopia and HCQ retinopathy was noted. More investigation is needed to clarify this association.

Visual field examinations using different strategies in Asian patients taking hydroxychloroquine

In this study, we investigated the patterns of visual field (VF) defects and the diagnostic abilities of VF tests using different strategies in Asian patients with hydroxychloroquine retinopathy. Patients screened for hydroxychloroquine retinopathy using optical coherence tomography, fundus autofluorescence, VF, and/or multifocal electroretinography were included. The VF was performed using the Humphrey 30-2 and/or 10-2 strategy, and 2,107 eyes of 1,078 patients with reliable results, including 136 eyes of 68 patients with hydroxychloroquine retinopathy, were analyzed. The characteristics of VF findings were evaluated and the sensitivity and specificity were compared between the 30-2 and 10-2 tests in subgroups of retinopathy severity and pattern. The most common VF defect pattern was partial- or full-ring scotoma in both the 10-2 and 30-2 tests. Among the eyes with hydroxychloroquine retinopathy that underwent both tests, 14.2% showed a disparity between the two tests, almost all at the early stage. In overall and early pericentral retinopathy, the sensitivity of the 30-2 test was significantly higher than that of the 10-2 test (95.7% vs. 77.1% and 90.6% vs. 53.1%, respectively; P < 0.05). However, the specificity of the 10-2 test was significantly higher than that of the 30-2 test (89.6% vs. 84.8%, P < 0.001). Therefore, the pattern of retinopathy should be carefully considered when choosing a VF strategy for better detection of hydroxychloroquine retinopathy.

Medium-term impact of the SARS-CoV-2 mRNA vaccine against disease activity in patients with systemic lupus erythematosus

OBJECTIVES

Numerous case reports have referred to new onset or flare of SLE after SARS-CoV-2 messenger RNA (mRNA) vaccines. Several observational studies showed that the short-term flare rate of SLE after SARS-CoV-2 vaccination is low. However, well-controlled clinical surveys are unavailable and the medium-term impact of the SARS-CoV-2 mRNA vaccines against the flare of SLE is uncertain. Therefore, we aimed to analyse the association between vaccination and medium-term subjective and objective disease activities of SLE and flares using matched pair methods.

METHODS

Altogether, 150 patients with SLE from the Kyoto Lupus Cohort were included. Patients who received two doses of the SARS-CoV-2 mRNA vaccines were 1:1 matched with unvaccinated patients based on the first vaccination date. The outcome measures were the SLE Disease Activity Index-2000 (SLEDAI-2K), the Japanese version of the SLE Symptom Checklist Questionnaire (SSC-J) and the Safety of Estrogens in Lupus Erythematosus National Assessment-SLEDAI flare index at 30, 60 and 90 days after vaccination.

RESULTS

SLEDAI-2K levels were not significantly different in vaccinated and unvaccinated patients with SLE at 30, 60 and 90 days after the second vaccination (adjusted estimate (95% CI): 30 days: -0.46 (-1.48 to 0.56), p=0.39; 60 days: 0.38 (-0.64 to 1.40), p=0.47; 90 days: 0.40 (-0.54 to 1.34), p=0.41). Similar results were observed in the SSC-J score (adjusted estimate (95% CI), 30 days: 0.05 (-1.46 to 1.56), p=0.95; 60 days: -0.63 (-2.08 to 0.82), p=0.40; 90 days: 0.27 (-1.04 to 1.58), p=0.69) and flare index (adjusted OR (95% CI), 30 days: 0.81 (0.36 to 1.85), p=0.62; 60 days: 1.13 (0.50 to 2.54), p=0.77; 90 days: 0.85 (0.32 to 2.26), p=0.74).

CONCLUSION

SARS-CoV-2 vaccination did not significantly influence the medium-term subjective and objective disease activities or flares of SLE until 90 days after the second vaccination.

Extreme Interocular Asymmetry in an Atypical Case of a Hydroxychloroquine-Related Retinopathy

Background and Objectives: Long-term hydroxychloroquine (HCQ) therapy can lead to retinal toxicity. Typically, it is characterized by a bull’s eye maculopathy. More recently, a “pericentral” form of HCQ retinopathy that predominantly affects patients of Asian descent has been described. To our knowledge, this is the first reported case where such an asymmetry between the right and the left eye in the toxicity profile is observed. Case presentation: The patient presented with a 12-year exposure to HCQ at a daily dose of 4.35 mg/kg. She presented an inferior pericentral-only phenotype of HCQ toxicity on the right eye and a perifoveal-only toxicity on the left eye. Modest progression of toxicity was observed on both eyes over the seven years of follow-up, despite drug discontinuation. Conclusions: To our knowledge, this is the first time that two different phenotypes of HCQ-related retinopathy are found in the same patient, challenging our understanding of the pathophysiology of HCQ retinal toxicity.

Clock-hour topography and extent of outer retinal damage in hydroxychloroquine retinopathy

In this study, we investigated the clock-hour topographic characteristics and extent of photoreceptor and retinal pigment epithelium (RPE) damage and correlated the extent with functional defects in eyes with hydroxychloroquine retinopathy. A total of 146 eyes of 75 patients diagnosed with hydroxychloroquine retinopathy were included. The clock-hour topographic characteristics (relative to the fovea) and extent of the photoreceptor and RPE defects in the parafoveal and pericentral areas were evaluated by reviewing the radial-scan optical coherence tomography (OCT) and wide-field fundus autofluorescence (FAF) images. The extent of outer retinal damage in the parafoveal and pericentral areas were correlated with the perimetric parameters of the Humphrey 10–2 and 30–2 tests, respectively. Although the photoreceptor damage was most commonly noted at the temporal to inferior locations in both parafoveal and pericentral areas, the RPE damage in the pericentral eyes was most commonly noted in the nasal area and showed topographic discrepancies with photoreceptor damage. The extent of RPE damage was almost identical between OCT and FAF images, whereas photoreceptor defect extent was significantly greater on OCT images. The extent of parafoveal and pericentral photoreceptor damage on OCT images was significantly correlated with perimetric parameters of the 10–2 and 30–2 tests, respectively (all P < 0.05). Our findings on the detailed topographic characteristics using a clock-hour-based system and significant correlation between the structural extent and perimetric parameters suggest that this evaluation may facilitate more comprehensive descriptions of structural damage extent and predictions of visual function.

Genotypes Influence Clinical Progression in EYS-Associated Retinitis Pigmentosa

Purpose

The purpose of this study was to investigate the genetic and clinical characteristics of eyes shut homolog (EYS)-associated retinitis pigmentosa (RP).

Methods

This was a retrospective cross-sectional observational study of 36 patients with EYS-associated autosomal recessive RP (arRP).

Results

The gene sequencing results revealed that c.6416G>A (p.Cys2139Tyr) and c.7228+1G>A were the two most predominant variants in our cohort and that variants near the C-terminus, which contains alternating laminin and epidermal growth factor (EGF) domains, accounted for the majority of the allele counts (58 of a total of 72) and relative allele frequencies (81%). Over half of the patients presented with pericentral-type RP (n = 19, 60%), which frequently occurred in combination with macular lesions (n = 10, 52%). Patients having both variants within the alternating laminin and EGF domains near the C-terminus had a more severe disease progression (average 0.045 logMAR increase per year) than those having one variant in the N-terminus and the other in the C-terminus (average 0.001 logMAR increase per year).

Conclusions

Pericentral RP was the major phenotype in patients with EYS-associated arRP. There was also a statistically significant relationship between the location of the variants and the severity of the disease.

Translational Relevance

This study may aid patients with EYS-associated arRP to predict future vision acuity based on their genetic and clinical features.

Delayed Detection of Predominantly Pericentral Hydroxychloroquine Toxicity in a Dominican Patient

PURPOSE

To describe delayed detection of pericentral hydroxychloroquine (HCQ) toxicity.

METHODS

67-year-old Dominican woman with rheumatoid arthritis on HCQ presented for examination.

RESULTS

Spectral-domain optical coherence tomography (SD-OCT) demonstrated bilateral cystoid macular edema with parafoveal attenuation of the external limiting membrane (ELM) and the ellipsoid zone (EZ). ELM and EZ disruption was present in inferior macula. While subtle superior defects were present on 10-2 visual fields, superior pericentral defects were noted on 24-2 testing. Hyperautofluorescence along inferior arcades corresponded to SD-OCT and visual fields. Examination 2 years prior demonstrated nonspecific points of depression on 10-2 visual fields and normal central SD-OCT findings. EZ and ELM disruption was present in the perifoveal inferior macula.

CONCLUSIONS

Early pericentral distribution of HCQ toxicity is not limited to Asian patients. Detecting pericentral HCQ toxicity involves reviewing entire macular cube on OCT. When OCT changes are suspected on parafoveal OCT B-scans, visual field testing with 24-2 may be more sensitive than 10-2.

Rapid Macular Thinning is an Early Indicator of Hydroxychloroquine Retinal Toxicity

PURPOSE

To demonstrate rapid macular thinning as an early and objective sign of hydroxychloroquine (HCQ) retinopathy.

DESIGN

Retrospective case cohort.

SUBJECTS

Cohort of 301 long-term HCQ therapy patients at Kaiser Permanente Northern California who had a minimum of four optical coherence tomography (OCT) studies which included Early Treatment Diabetic Retinopathy Study (ETDRS) retinal thickness values over a minimum interval of four years.

METHODS

Creation of sequential retinal thickness plots to show the rate of change in macular thickness within ETDRS regions.

MAIN OUTCOME MEASURES

1) Identification of rapid macular thinning, 2) Comparison of patients with rapid thinning to those with stable macular thickness, and 3) Comparison of rapid thinning patients with and without conventional OCT or 10-2 visual field signs of HCQ toxicity.

RESULTS

Retina thinning in 219 stable patients on long-term HCQ therapy averaged 0.62 ± 0.45 (mean ± standard deviation) microns per year, while 82 patients showed a period of relatively linear rapid thinning with a loss of 3.75 ± 1.34 microns per year. Of the patients with rapid thinning, 38 eventually developed conventional OCT or 10-2 visual field signs of HCQ retinal toxicity. The cumulative retinal thinning in these patients was 25.1 ± 6.2 microns compared to 15.7 ± 4.0 microns in those without conventional toxicity (p < 0.01).

CONCLUSIONS

Retinal thickness remains stable for many years in most patients on long-term HCQ therapy, but after a critical point the retina may begin to thin rapidly. Sequential plots of inner and outer ETDRS ring macular thickness provide objective evidence of this early structural change several years before conventional signs appear. This approach can alert patients and prescribing physicians to potential retinal damage and uses readily available OCT measurements that could be automated by manufacturers for use in comprehensive eyecare settings.

Current challenges and nanotechnology-based pharmaceutical strategies for the treatment and control of malaria

Malaria is one of the prevalent tropical diseases caused by the parasitic protozoan of the genus Plasmodium spp. With an estimated 228 million cases, it is a major public health concern with high incidence of morbidity and mortality worldwide. The emergence of drug-resistant parasites, inadequate vector control measures, and the non-availability of effective vaccine(s) against malaria pose a serious challenge to malaria eradication especially in underdeveloped and developing countries. Malaria treatment and control comprehensively relies on chemical compounds, which encompass various complications, including severe toxic effects, emergence of drug resistance, and high cost of therapy. To overcome the clinical failures of anti-malarial chemotherapy, a new drug development is of an immediate need. However, the drug discovery and development process is expensive and time consuming. In such a scenario, nanotechnological strategies may offer promising alternative approach for the treatment and control of malaria, with improved efficacy and safety. Nanotechnology based formulations of existing anti-malarial chemotherapeutic agents prove to exceed the limitations of existing therapies in relation to optimum therapeutic benefits, safety, and cost effectiveness, which indeed advances the patient's compliance in treatment. In this review, the shortcomings of malaria therapeutics and necessity of nanotechnological strategies for treating malaria were discussed.

Pyridoxal Kinase of Disease-causing Human Parasites: Structural and Functional Insights to Understand its Role in Drug Discovery

Abstract:

Human parasites cause several diseased conditions with high morbidity and mortality in a large section of the population residing in various geographical areas. Nearly three billion people suffer from either one or many parasitic infections globally, with almost one million deaths annually. In spite of extensive research and advancement in the medical field, no effective vaccine is available against prominent human parasitic diseases that necessitate identification of novel targets for designing specific inhibitors. Vitamin B6 is an important ubiquitous co-enzyme that participates in several biological processes and plays an important role in scavenging ROS (reactive oxygen species) along with providing resistance to oxidative stress. Moreover, the absence of the de novo vitamin B6 biosynthetic pathway in human parasites makes this pathway indispensable for the survival of these pathogens. Pyridoxal kinase (PdxK) is a crucial enzyme for vitamin B6 salvage pathway and participates in the process of vitamers B6 phosphorylation. Since the parasites are dependent on pyridoxal kinase for their survival and infectivity to the respective hosts, it is considered a promising candidate for drug discovery. The detailed structural analysis of PdxK from disease-causing parasites has provided insights into the catalytic mechanism of this enzyme as well as significant differences from their human counterpart. Simultaneously, structure-based studies have identified small lead molecules that can be exploited for drug discovery against protozoan parasites. The present review provides structural and functional highlights of pyridoxal kinase for its implication in developing novel and potent therapeutics to combat fatal parasitic diseases.

RetINal Toxicity And HydroxyChloroquine Therapy (INTACT): protocol for a prospective population-based cohort study

PURPOSE

Hydroxychloroquine (HCQ) is an important medication for patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and other rheumatic diseases. Although it is well-tolerated and cost-effective, the risk of HCQ retinal toxicity is of increasing concern. The aim of this study is to re-examine the HCQ retinal toxicity incidence rate, risk factors and clinical course after discontinuation.

METHODS

We designed a prospective population-based cohort study in adult patients with SLE or RA, currently receiving HCQ for five or more years, who are residents of British Columbia (BC), Canada. Based on administrative data, we identified 5508 eligible participants (1346 SLE and 4162 RA). They will participate in annual or biannual retinal screening over 5 years in alignment with the recently revised American Academy of Ophthalmology guidelines. To standardise procedures for retinal screening, imaging, diagnostic criteria, severity staging and data transfer, a consensus meeting was convened in December 2019 with participation of BC retinal specialists and the research team. Agreement was attained on: use of spectral domain-optical coherence tomography as the primary objective screening modality; classification of images into categories of normal, equivocal or abnormal; and transferring the equivocal and abnormal images plus corresponding subjective test results via cloud-based server from each clinic to a reading centre. Confirmation of HCQ retinal toxicity diagnoses and severity staging will be performed by three independent and masked reviewers. The incidence of HCQ retinal toxicity will be calculated, accounting for the competing risk of death. Hazard ratios for each risk factor will be calculated for the risk of HCQ retinopathy, after adjusting for confounders. We will also estimate the risk of HCQ retinal toxicity progression over 5 years.

ETHICS AND DISSEMINATION

This study has received approval from the University of British Columbia Clinical Research Ethics Board (H20-00736) and the Vancouver Coastal Health Research Institute.

Novel imaging techniques for hydroxychloroquine retinopathy

Hydroxychloroquine retinopathy is an increasingly recognized cause of iatrogenic, irreversible visual impairment due to the expanding use of hydroxychloroquine in combination with improvements in disease detection following advances in retinal imaging techniques. The prevalence of disease is estimated to be greater than 5% amongst individuals who have used the drug for 5 years or more. In addition to conventional imaging modalities, such as spectral-domain optical coherence tomography (OCT) and fundus autofluorescence (FAF), novel retinal imaging techniques such as en face OCT, OCT angiography, fluorescence lifetime imaging ophthalmoscopy, quantitative autofluorescence, and retromode imaging are capable of detecting structural changes in the retina. These novel retinal imaging techniques have shown promise in detecting earlier disease than is possible with current mainstream imaging modalities. Moreover, these techniques may identify disease progression as well as enabling functional correlation. In the future, these novel imaging techniques may further reduce the risk of visual loss from hydroxychloroquine retinopathy through the earlier detection of pre-clinical disease.

Update on Retinal Drug Toxicities

Purpose of Review

This review aims to provide an update on the clinical presentations and diagnostic findings of drug-induced retinal toxicities.

Recent Findings

Several newly FDA-approved medications have been associated with acute retinal toxicities, including brolucizumab, MEK inhibitors, ulixertinib, and FGFR inhibitors. Additionally, as previously believed-to-be well-tolerated medications, such as pentosan sulfate sodium, anti-retroviral therapies, and certain intraoperative ocular medications, are used more frequently or for longer periods of time, associated toxic retinopathies and inflammatory reactions have been reported. Finally, advances in ocular imaging have revealed novel findings in hydroxychloroquine and tamoxifen maculopathies.

Summary

Discovery of new medications, increased frequency of use, and longer-term use have led to increased reports of retinal toxicities. Advances in retinal imaging have allowed for earlier detection of subclinical changes associated with these medications, which may help prevent progression of disease. However, more research is needed to determine the point at which vision loss becomes irreversible. Risks and benefits must be assessed prior to discontinuation of the offending, but potentially lifesaving, therapy.

Screening for Hydroxychloroquine Retinal Toxicity in Indian Patients

OBJECTIVE

Several studies have reported hydroxychloroquine (HCQ) retinal toxicity in East Asian patients. However, at present, there are limited data from Indian patients. The aim of this study was to investigate the prevalence and pattern of HCQ retinal toxicity in Indian population and to see if screening protocol for retinal toxicity in Indian patients should be any different to others.

METHODS

This was a cross-sectional study involving adult patients with autoimmune rheumatic diseases who had received HCQ for at least 5 years or a cumulative dose of at least 500 g. Retinal toxicity was evaluated using fundus examination, visual fields 10-2 and 30-2 protocol, and spectral domain optical coherence tomography.

RESULTS

Of 110 patients screened, retinal toxicity was found in 7 patients (6.36%). A parafoveal pattern was found in 4 patients, whereas a mixed parafoveal and perifoveal pattern was found in 3 patients. None of the patients had isolated perifoveal pattern. Except for the one patient, all the patients with retinal toxicity had more than 10 years (mean, 13 ± 4.89 years; range, 5-20 years) of HCQ usage with a mean cumulative dose of 1573.7 ± 771.5 g. The mean daily dose was 5 ± 1.6 mg/kg per day.

CONCLUSIONS

Hydroxychloroquine retinal toxicity is more common than previously recognized in patients who have used the drug for more than 5 years. The toxicity manifests as a parafoveal or a mixed parafoveal and perifoveal pattern in Indian patients.

Evaluating the Use of Hydroxychloroquine in Treating Patients With Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is one of the most common autoimmune diseases present today. Although treatment options may differ among clinicians, a commonly prescribed treatment is hydroxychloroquine (HCQ), alone or in combination with other medications. HCQ has been studied for its immunomodulatory effects as well as its role in treating adverse conditions associated with RA. This systematic review examined the use of HCQ therapy in RA patients. A systematic search for relevant literature through PubMed, National Institute of Informatics, Japan (CiNii), and Science Direct databases were carried out in August 2021. Literature directly related to HCQ therapy for RA patients, RA-associated chronic kidney disease, and cardiovascular disease (including lipid profile) was considered relevant. HCQ associated retinopathic adverse effects were also selected for this review. Thirty-eight articles were found to be relevant, passed quality assessment, and were included in this review. Nine articles discussed HCQ therapy in comparison with other therapies (mainly methotrexate and sulfasalazine), but were contradictory in their outcomes, as were the seven papers that reviewed kidney function in RA patients with and without HCQ. Five articles credited better cardiovascular outcomes to RA patients taking HCQ. Sixteen articles studied the relationship between HCQ and retinal toxicity, providing insights into the risks associated with HCQ therapy. HCQ therapy was found not only to be beneficial in slowing the disease progression in RA patients but enhanced the effects of methotrexate in treating RA as well. Data strongly associates HCQ therapy with the mitigation of RA-related cardiovascular and kidney conditions. However, if HCQ is prescribed, it is imperative to be aware of the possible (although rare) retinopathic adverse effects associated with this therapy.

Safety of long-term use of four common conventional disease modifying anti-rheumatic drugs in rheumatoid arthritis

Conventional disease-modifying antirheumatic drugs (DMARDs) have been used in the management of rheumatoid arthritis for a long time. Whereas methotrexate (MTX) is the anchor drug, leflunomide, hydroxychloroquine and sulfasalazine are used along with MTX either in combination or sequentially. Together these four drugs are the most commonly used DMARDs. They are also used in combination with biological DMARDs (bDMARDs) to enhance their efficacy and MTX in particular to reduce antibodies against anti-tumour necrosis factor. Despite their widespread use, concerns regarding their safety especially when used long-term hinder their optimum use in clinical medicine. In this narrative review we have critically appraised the available literature regarding the safety of these four DMARDs when used long-term.

Impact of Structural Changes on Multifocal Electroretinography in Patients With Use of Hydroxychloroquine

Purpose

To investigate the relationship between retinal structure and macular function in eyes screened for hydroxychloroquine (HCQ) toxicity.

Methods

Participants referred for hydroxychloroquine retinopathy screening with spectral domain optical coherence tomography (SD-OCT) and multifocal electroretinogram (mfERG) testing were included in the analysis. Amplitude and implicit time of mfERG N1 and P1 responses were included in the analysis. Ring ratios were computed for amplitude values as the ratio of rings 1–3:5 (R1–3:R5). A control group of healthy participants was included for comparison of SD-OCT metrics.

Results

Sixty-three eyes screened for HCQ retinopathy and 30 control eyes were analyzed. The outer nuclear layer (ONL) was significantly thinner in HCQ patients in the foveal (P = 0.008), parafoveal (P < 0.0001), and perifoveal (P < 0.0001) regions. The HCQ cohort was further divided into two subgroups according to the presence of structural clinically detectable retinopathy (i.e., structural damage as detected by multimodal imaging). HCQ eyes without retinopathy had a thinner ONL thickness in the foveal (P = 0.032), parafoveal (P < 0.0001), and perifoveal (P < 0.0001) regions and a thinner inner nuclear layer (INL) in the parafoveal region (P = 0.045 versus controls). Structural changes in HCQ patients without retinopathy were significantly associated with macular function as R2:R5 ring ratio of mfERG P1 amplitude was associated with INL (P = 0.002) and ONL (P = 0.044) thicknesses, and R3:R5 ring ratio of P1 amplitude was associated with ONL thickness (P = 0.004).

Conclusions

Our results suggest that structural alterations secondary to HCQ toxicity may occur in the absence of clinically detectable retinopathy, and this may reflect in an impaired macular function.

Fundus Autofluorescence and Clinical Applications

Fundus autofluorescence (FAF) has allowed in vivo mapping of retinal metabolic derangements and structural changes not possible with conventional color imaging. Incident light is absorbed by molecules in the fundus, which are excited and in turn emit photons of specific wavelengths that are captured and processed by a sensor to create a metabolic map of the fundus. Studies on the growing number of FAF platforms has shown each may be suited to certain clinical scenarios. Scanning laser ophthalmoscopes, fundus cameras, and modifications of these each have benefits and drawbacks that must be considered before and after imaging to properly interpret the images. Emerging clinical evidence has demonstrated the usefulness of FAF in diagnosis and management of an increasing number of chorioretinal conditions, such as age-related macular degeneration, central serous chorioretinopathy, retinal drug toxicities, and inherited retinal degenerations such as retinitis pigmentosa and Stargardt disease. This article reviews commercial imaging platforms, imaging techniques, and clinical applications of FAF.

An objective method of diagnosing hydroxychloroquine maculopathy

BACKGROUND

Hydroxychloroquine (HCQ) maculopathy is irreversible; primary prevention is done by regular monitoring. Guidelines of the Royal College of Ophthalmologists identify definite toxicity as having abnormal results of two screening tests, we present a quantitative method for interpreting these guidelines.

METHODS

We obtained ocular coherence tomography (OCT) scans of 100 patients who have been on HCQ for 5 years or more (patients) and 70 age-matched controls. Both groups had 10'2 visual field (VF) test. We used linear regression to determine the cut-off points for each of the eight Early Treatment of Diabetic Retinopathy Study (ETDRS) macular sectors for the VF and OCT. We calculated the probability of developing maculopathy using logistic regression.

RESULTS

Mean patient age: 59.9 years, 85% females, no statistically significant age difference between the patients and the control groups.

DIAGNOSIS

64% rheumatoid arthritis, 14% Sjogren's syndrome, 16% systemic lupus and 6% various other rheumatology conditions. Mean duration of use was 6.3 years. Logistic regression results show strong negative correlation between the outer nuclear layer (ONL) volume and probability of toxicity. Goodness of fit was tested using Hosmer and Lemeshow test that indicates a high significance with a high P-value of 1.

CONCLUSIONS

Combining the ONL volume reduction and VF retinal sensitivity reduction per each of the eight ETDRS macular sectors provides an accurate and objective way of diagnosing HCQ maculopathy, this helps busy eye units establishing an optometrist-led or virtual service because it is independent of the assessor's level of experience.

Ocular findings in Japanese patients with hydroxychloroquine retinopathy developing within 3 years of treatment

PURPOSE

To describe the characteristics of Japanese patients with hydroxychloroquine (HCQ) retinopathy developing within 3 years of treatment outset.

STUDY DESIGN

Retrospective case series METHODS: Three patients with HCQ retinopathy developing within 3 years of treatment outset have been identified in Japan since HCQ became available in 2015. Their medical charts, containing optical coherence tomography (OCT), fundus autofluorescence imaging, and visual field tests, were reviewed.

RESULTS

The treatment durations and cumulative doses until onset were 29-36 months and 182-326 g, respectively. The first patient had possible pre-existing maculopathy, although the abnormalities were ambiguous. The second and third patients had impaired renal function. The patients did not complain of severe visual disturbance at diagnosis, but visual field loss and disruption of the outer retinal segments consisting of a parafoveal pattern in the first case and a pericentral pattern (localized, 8 or more degrees from the center of the fovea) in the second and third cases were clearly observed on OCT. Even after HCQ discontinuation, their retinopathy showed slight progression on the visual field tests and OCT images. A blood sample was obtained from 1 patient on the day after HCQ discontinuation, and the whole blood level of HCQ was measured using validated liquid chromatography-tandem mass spectrometry. The HCQ level 27 h after the last dose was high, at 2240 ng/mL (suggested threshold > 1733 ng/mL).

CONCLUSION

Ophthalmologic screening from the initiation of HCQ treatment detected 3 cases of HCQ retinopathy developing within 3 years of treatment outset, including a patient with a high blood level of HCQ.

Therapeutic Potential of Exploiting Autophagy Cascade Against Coronavirus Infection

Since its emergence in December 2019 in Wuhan, China, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) created a worldwide pandemic of coronavirus disease (COVID-19) with nearly 136 million cases and approximately 3 million deaths. Recent studies indicate that like other coronaviruses, SARS-CoV-2 also hijacks or usurps various host cell machineries including autophagy for its replication and disease pathogenesis. Double membrane vesicles generated during initiation of autophagy cascade act as a scaffold for the assembly of viral replication complexes and facilitate RNA synthesis. The use of autophagy inhibitors - chloroquine and hydroxychloroquine initially appeared to be as a potential treatment strategy of COVID-19 patients but later remained at the center of debate due to high cytotoxic effects. In the absence of a specific drug or vaccine, there is an urgent need for a safe, potent as well as affordable drug to control the disease spread. Given the intricate connection between autophagy machinery and viral pathogenesis, the question arises whether targeting autophagy pathway might show a path to fight against SARS-CoV-2 infection. In this review we will discuss about our current knowledge linking autophagy to coronaviruses and how that is being utilized to repurpose autophagy modulators as potential COVID-19 treatment.

A novel KCNV2 mutation in a patient taking hydroxychloroquine associated with cone dystrophy with supernormal rod response

BACKGROUND

Cone dystrophy with supernormal rod response (CDSRR) is a rare inherited retinal degeneration. A patient superimposed with medical conditions requiring use of hydroxychloroquine (HCQ) may obscure accurate diagnosis of CDSRR. Herein, we report a referral case for HCQ retinopathy screening. Comprehensive ophthalmic examinations, however, guided the diagnosis of CDSRR from a novel mutation in potassium voltage-gated channel modifier subfamily V member 2 (KCNV2) gene.

MATERIALS AND METHODS

Comprehensive ophthalmic examinations were evaluated for two patients whose parents are first cousins. Direct sanger sequencing of KCNV2 was applied to confirm the mutation.

RESULTS

A 38-year-old male proband was referred for HCQ retinopathy screening after taking HCQ for systemic lupus erythematosus (SLE). Fundus examination showed bull's eye pattern, and photoreceptor loss in the foveal region of both eyes was noted on spectral domain-optical coherence tomography (SD-OCT). The full-field electroretinography (ffERG) revealed a disproportionate increase in scotopic maximal response with implicit time delay, as well as universal cone dysfunction. Proband's 24-year-old sister had similar ffERG pattern in both eyes. Direct sanger sequencing of KCNV2 gene revealed a novel homozygous mutation c.280_281 insG (p.Ala94GlyfsTer278), confirming a diagnosis of CDSRR.

CONCLUSIONS

We report a novel KCNV2 mutation in a consanguineous family. The unique ffERG features of CDSRR are pathognomonic and thus crucial in guiding clinicians toward genetic testing of the KCNV2 gene. Altogether, multimodal imaging, ffERG, and detailed history taking are important diagnostic tools for differentiating between acquired and inherited retinal disorders.

SEQUENTIAL RETINAL THICKNESS ANALYSIS SHOWS HYDROXYCHLOROQUINE DAMAGE BEFORE OTHER SCREENING TECHNIQUES

PURPOSE

We sought to determine the earliest diagnostic signs of hydroxychloroquine retinopathy up to the point of clinical recognition.

METHODS

Retrospective series of 6 patients (5 parafoveal disease; 1 pericentral disease) with at least 3 examinations over 3.5 years or more preceding diagnosis of HCQ retinopathy. Spectral domain optical coherence tomography (sdOCT) cross-sections, fundus autofluorescence (FAF) and visual fields were generated clinically. Stored sdOCT data were re-examined later to generate topographic ellipsoid zone (EZ) maps, minimum intensity (MI) analysis and sequential plots of regional retinal thickness. Retrospective series of six patients (5 parafoveal disease; one pericentral disease) with at least three examinations over 3.5 years or more preceding diagnosis of hydroxychloroquine retinopathy.

RESULTS

Spectral domain optical coherence tomography cross-sections and fields showed similar sensitivity; fundus autofluorescence was not helpful. In parafoveal cases, EZ topography and minimum intensity analysis were no more reliable. Sequential thickness plots from four parafoveal cases showed dramatic retinal thinning across the posterior pole beginning 4 years to 5 years before clinical diagnosis, with parafoveal regions thinning even faster. The pericentral case showed thinning only outside the central macula. Peripheral EZ loss was more dramatic with EZ topography than sdOCT cross-sections.

CONCLUSION

Sequential retinal thickness plots reveal definitive thinning years before current diagnostic procedures. We hope that OCT manufacturers will develop software to display such measurements. Ellipsoid zone topography was not more sensitive than sdOCT cross-sections, but important for recognizing pericentral disease.

American College of Rheumatology, American Academy of Dermatology, Rheumatologic Dermatology Society, and American Academy of Ophthalmology 2020 Joint Statement on Hydroxychloroquine Use With Respect to Retinal Toxicity

Four major medical societies involved with hydroxychloroquine (HCQ) therapy concur on the need for common principles and cooperation to minimize the risk of ocular toxicity. At a daily dosage of ≤5 mg/kg/day actual body weight, the risk of retinal toxicity from HCQ is <2% for usage up to 10 years. Widespread adoption of more sensitive testing techniques, such as optical coherence tomography and automated visual fields, by eye care providers will allow the detection of early toxicity and thus preserve the patient's visual function. Baseline testing is advised to rule out confounding disease when a patient is started on HCQ. Annual screening with sensitive tests should begin no more than 5 years after treatment initiation. Providers should be sensitive to the medical value of HCQ, and not stop the drug for uncertain indications. It is important to note that effective communication among prescribing physicians, patients, and eye care providers will optimize the utility and safety of HCQ.

Prevalence of hydroxychloroquine retinopathy with long-term use in a cohort of Indian patients with rheumatic diseases

The study aims to estimate the prevalence of hydroxychloroquine (HCQ) retinopathy in a cohort of Indian patients and analyse the associated factors. Adult patients with rheumatological disorders aged ≥ 18 years using HCQ for more than 5 years and/or having received a cumulative dose > 400 g were included. Demographic and clinical data were collected and all underwent ophthalmological tests which included Humphrey automated visual fields (AVF) and spectral domain optical coherence tomography (SD-OCT). The various clinical characteristics of the patients were compared. The study included 110 patients with a mean age of 43.5 ± 10.1 years and predominantly females. Eleven patients (10%) were diagnosed with definite HCQ retinopathy. The mean daily dose of HCQ (mg/kg of real body weight) was significantly different in the groups with and without retinopathy (5.7 ± 0.9 vs 5.1 ± 0.8, p = 0.04). Patients with retinopathy had significantly more colour vision abnormalities (odds of 16.9; confidence interval 4.1-69.1, p = 0.0001) and higher prevalence of both parafoveal and perifoveal thinning (p < 0.0001). Age, gender, duration of HCQ use, cumulative HCQ dose and body mass index were not found to be associated with retinopathy. Four out of 11 patients had abnormalities only on 30-2 protocol for AVF testing, two had abnormalities only on 10-2 protocol, whereas five patients had abnormalities on both protocols. SD-OCT abnormalities were present in all patients with retinopathy. Hydroxychloroquine retinopathy was prevalent in the study cohort and significantly associated with a higher daily dose of HCQ (mg/kg real body weight).