Hydroxychloroquine and chloroquine retinopathy: a systematic review evaluating the multifocal electroretinogram as a screening test

Factors associated with early hydroxychloroquine-induced retinal toxicity in patients with systemic lupus erythematosus

PURPOSE

Hydroxychloroquine is currently recommended for the treatment of systemic lupus erythematosus (SLE), but it can cause irreversible retinal toxicity. This study aimed to identify factors associated with early hydroxychloroquine-induced retinal toxicity in patients with SLE from a single centre for 20 years.

METHODS

SLE patients diagnosed between 1998 and 2017 and followed up for at least 1 year were included. Demographic, clinical, laboratory and therapeutic data were collected from the electronic medical records and retrospectively analysed. Early hydroxychloroquine-induced retinal toxicity was defined as the development of macular toxicity within the first 5 years of hydroxychloroquine treatment.

RESULTS

A total of 345 patients followed for a median of 15 years were analysed; 337 (97.7%) patients received hydroxychloroquine, 38 (11.3%) of them presented with retinal toxicity, and 10 (3%) developed early retinal toxicity. These patients had a mean treatment duration of 3.3 years with a mean cumulative dose of 241 g. Patients were diagnosed by visual field (VF) and fundoscopy, and two were also assessed using spectral domain optical coherence tomography (SD-OCT). The median (IQR) age of patients with early toxicity was 56 (51-66) years, and 80% were female. Factors independently associated with early hydroxychloroquine-induced retinal toxicity were lupus anticoagulant positivity (OR 4.2; 95% CI 1.2-15.5) and hypercholesterolaemia (OR 5.6; 95% CI 1.5-21.5).

CONCLUSION

Our results suggest that lupus anticoagulant positivity and hypercholesterolaemia among SLE patients may be risk factors for early hydroxychloroquine-induced retinal toxicity, regardless of the dose or duration of treatment.

New proposal for a multimodal imaging approach for the subclinical detection of hydroxychloroquine-induced retinal toxicity in patients with systemic lupus erythematosus

OBJECTIVE

To compare multimodal structural and functional diagnostic methods in patients with systemic lupus erythematosus (SLE) treated with hydroxychloroquine, to identify the best complementary approach for detecting subclinical retinal toxicity.

METHODS

A cross-sectional, unicentric study was conducted on patients with SLE treated with hydroxychloroquine. Each patient underwent a comprehensive ophthalmic evaluation, comprising structural tests (spectral-domain optical coherence tomography (SD-OCT), en face OCT, en face OCT angiography (OCTA), fundus autofluorescence (FAF)) and functional tests (automated perimetry for visual field (VF) testing, multifocal electroretinography (mfERG)). A diagnosis of macular toxicity required the presence of abnormalities in at least one structural and functional test. The Kappa Concordance Index was used to assess the concordance among the different tests in detecting potential macular toxicity-associated alterations.

RESULTS

Sixty-six patients with SLE (132 eyes) were consecutively enrolled. Four (6.1%) patients developed subclinical hydroxychloroquine-induced retinal toxicity without visual acuity impairment. The proportion of abnormal results was 24% for both en face OCT and en face OCTA. Regarding functional analysis, VF was less specific than mfERG in detecting subclinical retinal toxicity (VF specificity 47.5%). En face OCT and en face OCTA structural findings showed better concordance, with a kappa index >0.8, and both identified the same cases of toxicity as FAF.

CONCLUSION

Although structural OCT and VF are frequently used to screen for hydroxychloroquine-induced retinal toxicity, our findings suggest that a combination of mfERG, en face OCT and en face OCTA could improve the diagnostic accuracy for subclinical retinal damage. This study emphasises the importance of a multimodal imaging strategy to promptly detect signs of hydroxychloroquine-induced retinal toxicity.

Accelerated hydroxychloroquine toxic retinopathy

PURPOSE

To report a case series of patients with retinal toxicity due to hydroxychloroquine (HCQ) within a short span of treatment.

METHODS

A retrospective review of case records of patients with accelerated HCQ toxicity within 1 year of starting the treatment was done. Systemic co-morbidities, details of HCQ treatment, details of ocular examination, and results of multimodal investigations were noted.

RESULTS

Nine patients (1 male, 8 females) with age ranging from 40 to 73 years (mean 54.2 ± 13.4 years) who showed accelerated HCQ toxicity were included. None had systemic conditions or drug history predisposing to early HCQ toxicity. The treatment duration ranged from 2 to 11 months and the cumulative HCQ dose ranged from 18 to 120 g (mean 45.0 ± 33.0 g). The visual acuity was normal in 8 (88.9%) patients and retinal evaluation was normal in 4 (44.4%). Optical coherence tomography was abnormal in 4 (44.4%). Six (66.6%) cases had reduced sensitivity in the parafoveal point on visual field testing. All 9 cases had multifocal electroretinographic changes diagnostic of HCQ toxicity. The HCQ treatment was stopped in 8 and continued with reduced dose in 1 patient. The mean duration of follow-up was 11.2 ± 9.6 months during which 5 patients showed improved mfERG and 1 patient had a stable mfERG. Visual fields improvement was noted in 2 cases.

CONCLUSIONS

Patients on HCQ need to be kept on regular monitoring with more frequent follow-ups to detect signs of early onset toxicity and prevent permanent visual impairment. mfERG is an important diagnostic tool for HCQ toxicity.

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.

Hydroxychloroquine retinopathy screening guidelines: a false positive

Hydroxychloroquine sulphate (HCQ) is widely used for the treatment of a variety of rheumatological and dermatological conditions. Despite the advantages of HCQ as a treatment option, it is important to be aware of its potential retinal toxicity, which may be irreversible and progressive. In December 2020, The Royal College of Ophthalmologists published revised recommendations on monitoring HCQ retinopathy. Our case report highlights some of the shortcomings of blindly following their monitoring algorithm by presenting a case where apparent HCQ retinopathy resolved after Yttrium Aluminium Garnet (YAG) laser capsulotomy. The case reiterates the importance of thorough clinical examination. We suggest that while the acquisition of the spectral domain optical coherence tomography and fundus autofluorescence may be objective, their interpretation is subjective. Even with the use of artificial intelligence algorithms, false positives may be generated if the tests are confounded by copathology. There is no gold-standard test for detecting HCQ toxicity.

Use of Visual Electrophysiology to Monitor Retinal and Optic Nerve Toxicity of Medications

It is important for clinicians to consider exposure to toxic substances and nutritional deficiencies when diagnosing and managing cases of vision loss. In these cases, physiologic damage can alter the function of key components of the visual pathway before morphologic changes can be detected by traditional imaging methods. Electrophysiologic tests can aid in the early detection of such functional changes to visual pathway components, including the retina or optic nerve. This review provides an overview of various electrophysiologic techniques, including multifocal electroretinogram (mfERG), full-field ERG (ffERG), electrooculogram (EOG), pattern electroretinogram (PERG), and visual evoked potential (VEP) in monitoring the retinal and optic nerve toxicities of alcohol, amiodarone, cefuroxime, cisplatin, deferoxamine, digoxin, ethambutol, hydroxychloroquine, isotretinoin, ocular siderosis, pentosane, PDE5 inhibitors, phenothiazines (chlorpromazine and thioridazine), quinine, tamoxifen, topiramate, vigabatrin, and vitamin A deficiency.

A novel 5-ring multifocal electroretinography stimulus for detecting hydroxychloroquine retinal toxicity

Purpose

Multifocal electroretinogram (mfERG) shows great utility as a screening tool to detect early hydroxychloroquine (HCQ) retinopathy, but its widespread use is limited by the lack of accessibility and long test duration. In this study, we evaluated a novel concentric 5-ring mfERG stimulus to provide a simplified and rapid protocol for screening HCQ toxicity.

Methods

Patients referred for HCQ retinopathy screening were consented to this observational cross-sectional study. Patients with amblyopia, high refractive error (more than 8 diopters), other retinal diseases precluding appropriate evaluation or history of retinal surgery were excluded. The data were collected from patients undergoing HCQ screening at a single center from July 2019 to March 2020. Patients were tested with the new concentric 5-ring mfERG stimulus, standard 61-hexagon mfERG stimulus, spectral domain optical coherence tomography and automated 10-2 visual fields. For the main outcome, the 5-ring mfERG was compared to 61-hexagon stimulus to determine the time-to-test completion and assess the association between ring (R1–R5) amplitude and ring ratio compared against cumulative dose, dose by real body weight and duration of therapy using Pearson correlation.

Results

In total, 52 patients (104 eyes; 5 males and 47 females) were recruited with a mean age of 59 years (range 23–85 years). The 5-ring protocol was markedly quicker to perform (1.3 ± 0.2 min; mean (SD)) compared to the 61-hexagon protocol (5.2 ± 0.6 min), p < 0.0001; n = 10 patients. The new R2/R5 ring ratio showed a moderate correlation with daily dose (r = − 0.640), cumulative dose (r = − 0.581) and duration of therapy (r = − 0.417). Similar correlations were observed with the new R2/R4 ring ratio which were not significantly different from the new R2/R5 correlation coefficients. The new R2/R5 ring ratio demonstrated a stronger correlation with daily (p = 0.002) and cumulative dose (p = 0.0001) compared to the 61-hexagon stimulus.

Conclusions

In this exploratory study, our novel 5-ring mfERG protocol significantly shortened data acquisition time while providing comparable results to the standard 61-hexagon stimulus for detecting HCQ-induced electrophysiological changes that are correlated with HCQ dosages and treatment duration. Our protocol has the potential to be more clinically practical by simplifying routine screening.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10633-021-09858-4.

Effect of spatial averaging on the amplitude ring ratio in multifocal electroretinography

PURPOSE

The purpose of this study was to evaluate the effect of spatial averaging on the multifocal electroretinography (mfERG) amplitude ring ratios used in screening for hydroxychloroquine (HCQ) toxicity.

METHODS

This was a retrospective review of the records of patients screened for HCQ retinopathy at the USF Eye Institute (University of South Florida) during the period of 2015-2020. Patients were tested binocularly with Diagnosys mfERG system (Diagnosys LLC, Lowell, MA). Only the records of patients referred internally were used. The effects of the lowest level (level 1, or 8%) of spatial averaging on the P1 amplitude ring ratios used for screening of HCQ maculopathy: R1/R2, R2/R5, R5/R3 and R5/R4, were evaluated.

RESULTS

The records of 40 patients (4 males, 36 females) aged 54.4 ± 14.1 years were selected for analysis. The use of spatial averaging had a significant effect on P1 amplitudes, and on the ring ratios and this effect was correlated with the magnitude of the amplitudes and the ratios. Spatial averaging diminished P1 amplitude significantly in ring 1 (p < 0.0001) and increased it slightly in ring 4 (p < 0.05), while it had no effect on the amplitude of the other three rings. Although as a group spatial averaging had a moderate effect on the R1/R2 ratio (~ -15%), on an individual basis the range was wide, from -36 to 43%. The effect on the other ring ratios was similar: The average group effect was ~ -5%, ~ -3.4% and ~ -4% for R2/R5, R5/R3 and R5/R4 ratios, but individual effects ranged from 0.18% to -27.3%, 0.9% to -14.2% and 0.9% to -26.2%, respectively.

CONCLUSIONS

For all ring ratios used in this analysis, spatial averaging has a substantial effect on the ring ratio, which could affect the interpretation of the results. Therefore, use of spatial averaging should be avoided when analyzing mfERG results for HCQ screening.

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.

Evaluation of optical coherence tomography angiography parameters in patients treated with Hydroxychloroquine

Background

One of the major side effects of Hydroxychloroquine (HCQ) is retinopathy. The aim of this study was to evaluate the Optical coherence tomography angiography (OCTA) parameters in a group of patients who have Hydroxychloroquine-induced retinopathy based on Multifocal electroretinography (mfERG) with a group who do not have retinopathy.

Method

This is a Cross-Sectional Study. In this study, patients with Rheumatoid arthritis (RA) or Systemic lupus erythematosus (SLE) who had been taking Hydroxychloroquine for at least 7 years were included. MfERG and OCTA imaging were performed for all patients. Patients were divided into Normal mfERG and Abnormal mfERG groups based on mfERG results. OCTA parameters were studied in these two groups.

Result

Sixty-one patients (61 eyes) were included. Forty-one patients had SLE and 20 patients had RA. Forty patients (66.7%) had Abnormal mfERG. The mean vascular density (VD) in Superficial capillary plexus (SCP) layer was not significantly different between Normal mfERG and Abnormal mfERG groups (P-Value> 0.05). Mean VD in SCP layer was not significantly different between Normal mfERG and Abnormal mfERG groups (P-Value> 0.05). In RA subgroup, mean VD in SCP layer in PeriFovea region in Abnormal mfERG group was significantly lower than normal group (P-Value < 0.05). Mean VD in deep capillary plexus (DCP) layer in Whole Image, Superior Hemi, Inferior Hemi, PeriFovea area in Abnormal mfERG group was significantly lower than normal group (P-Value < 0.05). This discrepancy was also observed in the RA subgroup but not in the SLE subgroup. The mean of none of the parameters of foveal avascular zone (FAZ) (mm2), Flow Area of Outer Retina (mm2) and Flow Area of Choriocapillaris (mm2) were not statistically significant between the groups Abnormal mfERG and Normal mfERG. (p-value> 0.05).

Conclusion

VD in the DCP layer decreased in abnormal mfERG patients compared to patients with normal mfERG. But it seems that VD in SCP layer, FAZ Area and Flow Area are similar in both groups. OCTA may be used as a non-invasive tool in the diagnosis of early stages of HCQ-induced retinopathy, especially in RA patients, but further studies are needed.

Long-Term Progression of Pericentral Hydroxychloroquine Retinopathy

PURPOSE

To investigate the long-term progression of pericentral hydroxychloroquine retinopathy.

DESIGN

Multicenter, retrospective cohort study.

PARTICIPANTS

Eighty eyes (60 with pericentral pattern) of 41 Korean patients with hydroxychloroquine retinopathy followed up for 2 years or more after drug cessation.

METHODS

Patients were screened for hydroxychloroquine retinopathy using spectral-domain or swept-source OCT, fundus autofluorescence (FAF), and Humphrey visual field (VF) tests. Follow-up was divided into short-term (≤2 years) and subsequent periods, and progression was evaluated in each period and severity group. Retinopathy progression on OCT was defined as increased length of the ellipsoid zone defect, decreased distance from the fovea to the photoreceptor defects, or newly developed or enlarged retinal pigment epithelium defects. On FAF, progression was defined as an increase in the area of hyperautofluorescence or hypoautofluorescence. Functional progression was defined as a regression coefficient of less than 0 dB/year for mean deviation and more than 0 dB/year for pattern standard deviation, based on linear regression analysis of 3 or more VF tests. Structural and functional progression rates were calculated using the slopes of retinal thicknesses on the Early Treatment Diabetic Retinopathy Study grid and perimetric parameters over time, respectively.

MAIN OUTCOME MEASURES

Structural and functional progression of retinopathy.

RESULTS

Approximately one third of eyes with early pericentral retinopathy showed limited progression during the short-term period after drug cessation, but they subsequently showed stable or improved photoreceptors. Most eyes with moderate pericentral retinopathy showed continuous progression, particularly when converted to the severe stage. Severe eyes showed progressive damage throughout the follow-up period. In all severity groups, the rates of retinal thinning decreased over time. In eyes with pericentral retinopathy showing progression, circumferential enlargement of retinal damage was prominent in earlier stages, whereas centripetal enlargement of the ring-shaped lesion was noted in advanced stages. Functional progression, noted in 58.7% of the pericentral eyes, corresponded with structural progression.

CONCLUSIONS

Pericentral hydroxychloroquine retinopathy showed severity-dependent progression. Moderate pericentral retinopathy usually progressed, but centripetal progression threatening the fovea was remarkable mostly in severe retinopathy. Our results suggest that early detection of retinopathy may minimize the risk of progression to foveal involvement in pericentral retinopathy.

What can visual caregivers expect with patients treated for SARS-CoV-2? An analysis of ongoing clinical trials and ocular side effects

Within the COVID-19 pandemic context, the WHO has proposed a list of medicines to treat patients with severe acute respiratory syndrome (SARS-CoV-2). An analysis of their ocular side effects was performed. Only chloroquine and hydroxychloroquine were found to have an ocular impact in the medium and long-term. Detailed search strategies were performed in EMBASE, MEDLINE, SCOPUS and WOS Core Collection. Additionally, the worldwide ongoing clinical trials including chloroquine or hydroxychloroquine were evaluated, and their proposals of drug administration and exclusion criteria analyzed. In general, high maximum cumulative doses of chloroquine or hydroxychloroquine are being used for a short period in 135 currently underway clinical trials (to 21st April 2020). Typically, the doses were 2 to 5 times greater than the AAO recommendation (adjusted to weight) to avoid toxic retinopathy, the most undesirable ocular side effect. Maximum cumulative doses up to 12,000 mg for chloroquine and 18,000 mg for hydroxychloroquine were found. In prophylaxis clinical trials, 72,000 mg and 22,500 mg were the maximum cumulative doses for hydroxychloroquine and chloroquine respectively. Only 48% of the clinical trials considered retinal impairment as an exclusion criterion, and just one referred to an ophthalmic examination previous to study inclusion. How chloroquine and hydroxychloroquine treatment affect patients with a previous retinal condition is still poorly understood. A comprehensive ophthalmological examination 6 months after treatment is recommended in this subgroup. This review provides an overview of this topic and sheds light on the challenges visual caregivers may face regarding these repurposed drugs.

Is optical coherence tomography angiography a useful tool in the screening of hydroxychloroquine retinopathy?

PURPOSE

To detect the early changes in retinal vasculature via optical coherence tomography angiography (OCTA) by comparing the quantitative OCTA parameters in the group of patients who were using hydroxychloroquine (HCQ) or not.

METHODS

This was a cross-sectional, comparative, and observational study. The patients who were newly or previously prescribed HCQ for an autoimmune disease were included. OCTA imaging was performed via OCT RT XR Avanti with AngioVue software (Optivue Inc, Freemont, CA). The study group had two groups: a control group (patients newly diagnosed and who were not taking any medication) and a treatment group (patients who were receiving HCQ treatment). The main outcome measure was OCTA parameters.

RESULTS

A total of 102 eyes of 102 patients were included. There were 70 patients in the treatment group and 32 patients in the control group. All of the vascular density values were similar between the control and treatment groups (p > 0.05 for all). However, the superficial whole thickness, superficial parafoveal thickness, superficial perifoveal thickness, deep whole thickness, deep parafoveal thickness, and deep perifoveal thickness were thinner in the treatment group than the control group (p < 0.05 for all).

CONCLUSION

Vascular density parameters did not differ between the control and treatment groups. However, the retinal thickness values were lower in the treatment group.

Use of OCT Retinal Thickness Deviation Map for Hydroxychloroquine Retinopathy Screening

PURPOSE

To investigate the use of a retinal thickness deviation map generated from swept-source (SS) OCT images for hydroxychloroquine retinopathy screening.

DESIGN

Retrospective cohort study.

PARTICIPANTS

This study included 1192 Korean patients with a history of hydroxychloroquine treatment: 881 patients (1723 eyes) in the discovery set and 311 patients (591 eyes) in the validation set. Patients were screened for retinal toxicity using SS OCT, fundus autofluorescence, and standard automated perimetry.

METHODS

According to the 2016 American Academy of Ophthalmology guidelines, hydroxychloroquine retinopathy was diagnosed by the presence of abnormalities on ≥1 objective structural tests alongside corresponding visual field defects. The 12 × 9-mm² macular volume SS OCT scan was performed, and the retinal thickness deviation map was generated automatically using the built-in software. On this map, yellow (retinal thickness, <5% of the normative level) or red (<1% of the normative level) pixels were defined as abnormal. Abnormal findings were evaluated, and diagnostic criteria were developed based on the discovery set data; criteria were validated using the validation set data.

MAIN OUTCOME MEASURES

The rate and patterns of abnormalities on the retinal thickness deviation map and sensitivity and specificity of the diagnostic criteria.

RESULTS

The retinal thickness deviation map showed the following abnormal patterns in eyes with hydroxychloroquine retinopathy: pericentral (36.0%) or parafoveal (6.1%) ring, mixed-ring (34.2%), central island (13.2%), and whole macular thinning (10.5%). The criterion of ≥5 contiguous red pixels showing 1 of the 5 characteristic patterns in both eyes yielded the greatest diagnostic performance (sensitivity and specificity of 98.2% and 89.1% and of 100% and 87.5% in the discovery and validation set data, respectively). Moreover, the area of abnormal pixels on the map was correlated significantly with the mean deviation (P < 0.001) and pattern standard deviation (P < 0.001) on the Humphrey 30-2 test in eyes with hydroxychloroquine retinopathy.

CONCLUSIONS

The retinal thickness deviation map may facilitate the objective evaluation of hydroxychloroquine retinopathy because it does not require subjective, morphologic evaluation of the outer retinal layers. The map has the potential to enhance hydroxychloroquine retinopathy screening when used in conjunction with conventional screening methods.

MICROPERIMETRY AS A SCREENING TEST FOR HYDROXYCHLOROQUINE RETINOPATHY: The Hard-Risk-1 Study

PURPOSE

To assess the sensitivity and specificity of microperimetry as a screening test to detecting hydroxychloroquine retinopathy.

METHODS

Retrospective cohort study. Patients with history of hydroxychloroquine use for more than 5 years and with concomitant microperimetry and multifocal electroretinogram testing were retrospectively reviewed. Microperimetry was considered positive if there were three or more contiguous scotoma points in the parafoveal region. Multifocal electroretinogram was used as gold standard and was considered positive if there was an increased R1/R2 ring ratio (>2.5) or reduced R1 absolute amplitude (<9.0). Sensitivity, specificity, positive predictive value, and negative predictive value of microperimetry were calculated.

RESULTS

A total of 197 patients were reviewed. Hydroxychloroquine retinopathy was present in 22 (11%) patients. Their mean (SD) age was 54 (14) years, and 96% were women. Their mean (SD) daily dose was 5.7 (1.3) mg/kg, cumulative dose was 2041 (1,548) g, and duration of use was 15 (10) years. Sensitivity, specificity, positive predictive value, and negative predictive value of microperimetry were 73%, 93%, 53%, and 96%, respectively.

CONCLUSION

Microperimetry has inferior sensitivity but good specificity in detecting hydroxychloroquine retinopathy (compared with multifocal electroretinogram). As such, it may be a useful ancillary test to exclude retinopathy, especially in high-risk patients or those with conflicting results on different modalities.

Electrophysiological and SD-OCT findings in patients receiving chloroquine therapy in relation to cumulative dosage and duration of treatment

PURPOSE

Assessment of multifocal ERG (mfERG) changes in patients treated with chloroquine and their correlation with morphological abnormalities, detected by spectral-domain optical coherence tomography in relation to cumulative dosage.

METHODS

Data from 37 eyes of 20 patients were retrospectively collected, and one randomly selected eye per patient was considered for statistical analysis. Eyes were divided into three groups according to mfERG and visual acuity findings: normal, early and advanced maculopathy. Functional measures of the first three mfERG rings were compared with retinal thickness measures of the corresponding OCT ETDRS circles. Data on cumulative dose and duration of therapy were also evaluated.

RESULTS

The mean mfERG values progressively decreased according to the stage of the disease. In particular in the early maculopathy group, amplitudes were significantly reduced in all the three central rings. The mean ring ratio R1/R2 was abnormal only in the early maculopathy group. OCT thickness measures were significantly lower in all the three ETDRS circles in the advanced maculopathy group, and in the paracentral circle in the early maculopathy group. Considering all the eyes, there was a statistically significant correlation between functional and morphological values (p < 0.001). High chloroquine cumulative dosages were always associated with retinal toxic effects, whereas lower cumulative dosages generated different levels of toxicity.

CONCLUSIONS

This study shows a strong association between mfERG ring values and the corresponding OCT thickness measures; however, mfERG may enhance early detection of functional changes in patients treated with chloroquine, especially in ambiguous cases. At low chloroquine cumulative dosages, different subjects might have different susceptibilities to the drug.

The Diagnostic Utility of Multifocal Electroretinography in Detecting Chloroquine and Hydroxychloroquine Retinal Toxicity

PURPOSE

To evaluate multifocal electroretinography (mfERG) as a screening test for detecting hydroxychloroquine and chloroquine toxicity.

DESIGN

Diagnostic accuracy study.

METHODS

Patients referred to the University of Ottawa for hydroxychloroquine or chloroquine retinopathy screening during 2011-2014 underwent 10-2 automated visual field, spectral domain optical coherence tomography, and mfERG testing. Patients with amblyopia, high myopia or hyperopia, coexisting retinal disease, or prior surgery were excluded. Abnormalities in parafoveal ring amplitudes or ring ratios were considered a positive mfERG result. We used the definition for hydroxychloroquine and chloroquine toxicity provided by the 2016 American Academy of Ophthalmology recommendations. Area under the curve (AUC) for each mfERG parameter and the sensitivity and specificity of mfERG were calculated. Logistic regression was used to model the effect of covariates in receiver operating characteristic (ROC) analyses.

RESULTS

In total, 63 patients (47 female, 16 male) were included. Of 120 eyes, 16 (13.3%) had toxicity according to the American Academy of Ophthalmology guidelines, and 39 (32.5%) had positive mfERG findings. mfERG was found to have a sensitivity of 1.00 (95% CI 0.79-1.00) and a specificity of 0.78 (95% CI 0.69-0.85). Ring 2 amplitude had the best performance among all parameters (AUC 0.97, 95% CI 0.94-1.00). Ring 2 amplitude decreased linearly with increasing cumulative dose and daily dose.

CONCLUSIONS

The high sensitivity of parafoveal depression on mfERG and its relationship to cumulative and daily dose illustrates an important role for objective functional testing. The high false-positive rate suggests a potential period where physiologic dysfunction is detected objectively on mfERG before structural change on spectral domain optical coherence tomography.

Comparison of Fundus-Guided Microperimetry and Multifocal Electroretinography for Evaluating Hydroxychloroquine Maculopathy

Purpose

To compare retinal function by using fundus-guided microperimetry (MP) and multifocal electroretinography (mfERG) for detecting hydroxychloroquine (HCQ) maculopathy.

Methods

Forty-six eyes of 25 patients referred to our clinical practice for HCQ maculopathy assessment and 3 groups of normal control subjects were evaluated by mfERG and MP. Macular structure was assessed using spectral-domain optical coherence tomography (SD-OCT). Ring ratios from the three innermost mERG rings were compared with average sensitivity of each MP ring at approximately equivalent distances from the fovea. HCQ toxicity was defined as an mfERG ring ratio or mean MP ring sensitivity >2 standard deviations below the normal mean. The sensitivity and specificity of MP to detect HCQ toxicity relative to mfERG were evaluated.

Results

MP rings MR2 and MR3 were positively correlated with corresponding mfERG ring ratios (r = 0.52, P = 0.002 and r = 0.56, P < 0.001 respectively). Ring 2 and ring 3 measures of MP and mfERG were significantly worse in HCQ eyes than controls (P < 0.001). The sensitivity of MP to detect toxicity for MR1 through MR3 ranged from 33% to 88%, whereas specificity ranged from 72% to 85%. Through rings 1 to 3, the frequency of abnormal function ranged from 20% to 48% for MP, 11% to 35% for mfERG, and 41% to 45% for SD-OCT.

Conclusions

The frequency of detection of HCQ toxicity with MP was greater than with mfERG. MP showed an overall good sensitivity and moderate specificity in detecting HCQ-induced functional deficits.

Translational Relevance

Results from this study may allow clinicians to improve screening accuracy for HCQ toxicity by using the alternative modality of MP.

Swept source optical coherence tomography angiography in patients treated with hydroxychloroquine: correlation with morphological and functional tests

PURPOSE

To evaluate swept source optical coherence tomography angiography (SS-OCTA) in patients treated with hydroxychloroquine (HCQ) for more than 5 years and to compare results with the tests currently recommended for screening of HCQ retinopathy.

METHODS

In this controlled pilot study, consecutive patients treated with HCQ for more than 5 years underwent SS-OCTA, SS-OCT B-scan and en-face C-scan, fundus autofluorescence (FAF), 10-2 automated visual field (AVF) testing and multifocal electroretinography (mfERG). On SS-OCTA, evaluation of the retinal superficial capillary plexus, middle capillary plexus, and deep capillary plexus (DCP) and the choriocapillaris (CC) was obtained.

RESULTS

We included 10 patients under HCQ treatment (20 eyes, mean age 38.91±11.73 years) and 18 healthy control patients (36 eyes, mean age 38.87±8.6 years). Mean duration of HCQ treatment was 10.0±3.25 (5-15) years and HCQ cumulative dose/body weight was 15.86±5.56 g/kg. The HCQ group showed a reduction of the vessel density in the 1 mm central, in the nasal and temporal subfields of DCP and in the 1 mm central subfield of CC, an increased foveal avascular zone in the three capillary plexuses, a greater frequency of CC flow voids and a reduced foveal choroidal thickness (p<0.05). Best-corrected visual acuity (BCVA), mfERG, SS-OCT B-scan and C-scan, AVF and FAF were normal in 20/20 eyes (100%).

CONCLUSIONS

In patients treated with HCQ for more than 5 years, choroidal thinning and flow abnormalities at SS-OCTA in the retinal capillary plexuses and CC may be observed even if BCVA, FAF, mfERG, AVF and SS-OCT are normal.

Evaluation of Retromode Imaging for Use in Hydroxychloroquine Retinopathy

PURPOSE

To report on the application of retromode imaging using infrared lasers to eyes with hydroxychloroquine (HCQ) retinopathy, and to compare retromode images with those acquired via conventional objective screening imaging modalities-optical coherence tomography (OCT) and fundus autofluorescence (FAF).

DESIGN

Diagnostic validity assessment.

METHODS

Setting: Institutional.

PATIENT POPULATION

Sixty-two eyes of 31 patients with systemic lupus erythematosus or rheumatoid arthritis who were treated with HCQ and developed HCQ retinopathy (patient group), 270 eyes of 135 patients with the same diseases who were treated with HCQ but exhibit no retinopathy (HCQ-taking control group), and 162 eyes of 81 normal controls (normal control group).

OBSERVATION PROCEDURES

Diagnosis of HCQ retinopathy was performed with screening tests recommended by the American Academy of Ophthalmology, including OCT, FAF, and visual field examination. Retromode imaging, using confocal scanning laser ophthalmoscopy, was performed for the patient group and both control groups. The findings on retromode imaging were correlated with outer retinal changes on OCT B-scan images, then compared with the FAF findings. The sensitivity and specificity of retromode imaging were calculated.

MAIN OUTCOME MEASURES

Findings of retromode imaging and sensitivity/specificity of the imaging.

RESULTS

All patients with HCQ retinopathy showed a parafoveal or pericentral ring-shaped or round area of decreased reflectance with prominent deep choroidal vessels, resulting in 100% sensitivity for the detection of retinopathy. Specificity of the imaging was 73.0% and 76.4% in the HCQ-taking control group and both control groups, respectively. Compared to FAF, retromode imaging enabled the detection of photoreceptor defects with greater sensitivity, particularly in eyes with early retinopathy. However, FAF provided additional information on the status of the retinal pigment epithelium, which could not be discriminated from photoreceptor defects in retromode imaging.

CONCLUSIONS

Retromode imaging may be useful for detecting HCQ retinopathy. However, its excellent sensitivity but limited specificity is suggestive of a supplementary role in screening HCQ retinopathy, particularly for early detection.

Comparison between multifocal ERG and C-Scan SD-OCT ("en face" OCT) in patients with a suspicion of antimalarial retinal toxicity: preliminary results

PURPOSE

Pericentral visual field changes and disruption of the ellipsoid layer on spectral domain optical coherence tomography (SD-OCT) are the main features of antimalarial retinal toxicity. C-Scan OCT or "en face" enables a topographic frontal view of the changes observed within the different retinal layers in particular the ellipsoid layer. The aim of this prospective study was to compare multifocal ERG (mfERG) responses with the results of C-Scan OCT ("en face" OCT) in patients with abnormal visual field and to analyze relationships between the structural and functional abnormalities.

METHODS

In 354 consecutive patients screened for antimalarial toxicity between January 1, 2014 and December 31, 2016, central visual field, mfERG recording, C-Scan OCT and short-wavelength fundus autofluorescent imaging were performed.

RESULTS

Among the 17/354 patients with abnormal central visual field results, all presented with abnormalities on the mfERG at least in one eye. In 16/33 eyes, there was a good concordance between focal loss of the mfERG response and the disruption of the ellipsoid layer on C-Scan OCT. In one eye with characteristic changes in the ellipsoid layer on the C-Scan OCT, the mfERG was normal, whereas in three eyes the mfERG was abnormal in eyes with a normal C-Scan OCT.

CONCLUSIONS

The contribution of the C-Scan OCT changes remains difficult to establish as there is no strict concordance with the local ERG responses. Although C-Scan OCT technology provides a new approach in analyzing focal abnormalities in the photoreceptor-retinal pigment epithelium interface, the sensitivity of this method compared with mfERG and other tests (central visual field, B-Scan OCT) needs to be evaluated. This study is still ongoing on a larger cohort.

Choroidal Thinning Associated With Hydroxychloroquine Retinopathy

PURPOSE

To investigate choroidal thickness in patients using hydroxychloroquine (HCQ) and compare choroidal thickness between eyes with and without HCQ retinopathy.

DESIGN

Retrospective case series.

METHODS

Setting: Institutional.

PATIENTS

We included 124 patients with systemic lupus erythematosus or rheumatoid arthritis who were treated with HCQ. The patients were divided into an HCQ retinopathy group and a control group, according to the presence or absence of HCQ retinopathy.

OBSERVATION

Total choroidal thickness and choriocapillaris-equivalent thickness were measured manually by 2 independent investigators using swept-source optical coherence tomography (SS-OCT; DRI-OCT, Topcon Inc, Tokyo, Japan). These measurements were made at the fovea and at nasal and temporal locations 0.5, 1.5, and 3 mm from the fovea. Medium-to-large vessel layer thickness was calculated accordingly. The thicknesses were compared between the HCQ retinopathy and control groups. We performed correlation analyses between choroidal thicknesses and details regarding HCQ use.

MAIN OUTCOME MEASURES

Total choroidal thickness and choriocapillaris-equivalent thickness.

RESULTS

Choroidal thicknesses were significantly decreased (P < .05) in the HCQ retinopathy group compared to the control group, except at the temporal choroid 1.5 mm from the fovea. Choriocapillaris-equivalent thicknesses were significantly different in all choroidal locations between the groups. In contrast, the medium-to-large vessel layer thickness was only significantly different at a few locations. The cumulative dose/body weight was significantly correlated with subfoveal choroidal and choriocapillaris-equivalent thicknesses (both P = .001). The association between presence of HCQ retinopathy and choroidal thicknesses was also statistically significant after adjusting for age, diagnosis for HCQ use, refractive errors, and duration of HCQ use (P = .001 and P = .003 for subfoveal choroidal and choriocapillaris-equivalent thickness, respectively).

CONCLUSIONS

These results all suggest that HCQ retinopathy is associated with choroidal thinning, especially in the choriocapillaris. Our results may suggest choroidal involvement of HCQ toxicity.

Targeting Autophagy in Cancer: Update on Clinical Trials and Novel Inhibitors

Eukaryotes use autophagy as a mechanism for maintaining cellular homeostasis by degrading and recycling organelles and proteins. This process assists in the proliferation and survival of advanced cancers. There is mounting preclinical evidence that targeting autophagy can enhance the efficacy of many cancer therapies. Hydroxychloroquine (HCQ) is the only clinically-approved autophagy inhibitor, and this systematic review focuses on HCQ use in cancer clinical trials. Preclinical trials have shown that HCQ alone and in combination therapy leads to enhancement of tumor shrinkage. This has provided the base for multiple ongoing clinical trials involving HCQ alone and in combination with other treatments. However, due to its potency, there is still a need for more potent and specific autophagy inhibitors. There are multiple autophagy inhibitors in the pre-clinical stage at various stages of development. Additional studies on the mechanism of HCQ and other autophagy inhibitors are still required to answer questions surrounding how these agents will eventually be used in the clinic.

Hydroxychloroquine for treatment of rheumatoid arthritis: multifocal electroretinogram and laser flare-cell photometry study

Purpose

To evaluate early changes in multifocal electroretinogram (mfERG) and subclinical aqueous humor flare and cellularity in patients receiving hydroxychloroquine (HCQ) as treatment for rheumatoid arthritis.

Methods

Ten patients receiving treatment with HCQ and no ophthalmic symptoms were enrolled. After complete ocular examination, mfERG and laser flare-cell photometry were performed. Patients were also divided into two subgroups with HCQ cumulative dose (CD) higher or lower than 500 g. Results obtained were compared with a control group of ten healthy subjects and statistical analysis was performed.

Results

In patients receiving HCQ treatment, mfERG P1-wave in ring 2 showed a significant reduction in amplitude and a significant increase in latency compared to healthy control subjects, respectively resulting in 1.143 μV vs 1.316 μV (P=0.040) and 38.611 ms vs 36.334 ms (P=0.024). These changes are highly related to CD. Furthermore, when using the laser flare-cell photometry, a significant increase in aqueous humor flare and cellularity was shown in patients with CD higher than 500 g, resulting in a mean value of 14.4 ph/ms compared to 8.1 ph/ms in patients with CD lower than 500 g (P=0.0029). These reports appear highly related to CD (P=0.001). Receiver operating characteristic curve analysis showed mfERG P1-wave amplitude in ring 2 as the most sensitive value in detecting early HCQ-related retinopathy.

Conclusion

MfERG was shown to be a very sensitive test in detecting early retinal toxicity and should be used for the screening of patients receiving HCQ treatment. Although less sensitive, laser flare-cell photometry can provide further information to evaluate early toxic retinal cell damage.

Hydroxychloroquine retinopathy

Hydroxychloroquine (HCQ; Plaquenil) is used increasingly in the management of a variety of autoimmune disorders, with well established roles in dermatology and rheumatology and emerging roles in oncology. Hydroxychloroquine has demonstrated a survival benefit in patients with systemic lupus erythematosus; some clinicians advocate its use in all such patients. However, Hydroxychloroquine and chloroquine (CQ) have been associated with irreversible visual loss due to retinal toxicity. Hydroxychloroquine retinal toxicity is far more common than previously considered; an overall prevalence of 7.5% was identified in patients taking HCQ for greater than 5 years, rising to almost 20% after 20 years of treatment. This review aims to provide an update on HCQ/CQ retinopathy. We summarise emerging treatment indications and evidence of efficacy in systemic disease, risk factors for retinopathy, prevalence among HCQ users, diagnostic tests, and management of HCQ retinopathy. We highlight emerging risk factors such as tamoxifen use, and new guidance on safe dosing, reversing the previous recommendation to use ideal body weight, rather than actual body weight. We summarise uncertainties and the recommendations made by existing HCQ screening programmes. Asian patients with HCQ retinopathy may demonstrate an extramacular or pericentral pattern of disease; visual field testing and retinal imaging should include a wider field for screening in this group. HCQ is generally safe and effective for the treatment of systemic disease but because of the risk of HCQ retinal toxicity, modern screening methods and ideal dosing should be implemented. Guidelines regarding optimal dosing and screening regarding HCQ need to be more widely disseminated.

Ocular Involvement in Systemic Autoimmune Diseases

Eye involvement represents a common finding in patients with systemic autoimmune diseases, particularly rheumatoid arthritis, Sjogren syndrome, seronegative spondyloarthropathy, and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. The eye is a privileged immune site but commensal bacteria are found on the ocular surface. The eye injury may be inflammatory, vascular or infectious, as well as iatrogenic, as in the case of hydroxychloroquine, chloroquine, corticosteroids, and bisphosphonates. Manifestations may affect different components of the eye, with episcleritis involving the episclera, a thin layer of tissue covering the sclera; scleritis being an inflammation of the sclera potentially leading to blindness; keratitis, referring to corneal inflammation frequently associated with scleritis; and uveitis as the inflammation of the uvea, including the iris, ciliary body, and choroid, subdivided into anterior, posterior, or panuveitis. As blindness may result from the eye involvement, clinicians should be aware of the possible manifestations and their management also independent of the ophthalmologist opinion as the therapeutic approach generally points to the underlying diseases. In some cases, the eye involvement may have a diagnostic implication, as for episcleritis in rheumatoid arthritis, or acute anterior uveitis in seronegative spondyloarthritis. Nonetheless, some conditions lack specificity, as in the case of dry eye which affects nearly 30 % of the general population. The aim of this review is to elucidate to non-ophthalmologists the major ocular complications of rheumatic diseases and their specific management and treatment options.

The Role of Multifocal Electroretinography in the Assessment of Drug-Induced Retinopathy: A Review of the Literature

Multifocal electroretinography (mfERG) is an objective, noninvasive examination for the assessment of visual function. It enables the stimulation of multiple retinal areas simultaneously and recording of each response independently, providing a topographic measure of retinal electrophysiological activity in the central 40-50° of the retina. A clinical application of mfERG represents the assessment of retinal toxicity associated with systemic medications. Drug-induced retinopathy represents a disease that, although not common, requires early recognition: if not detected early, it may progress and cause irreversible retinal dysfunction with subsequent visual impairment. This review aims to evaluate the use of mfERG in the assessment of retinal dysfunction associated with various systemic pharmacological agents based on the currently available literature. The most commonly recognized systemic medications affecting retinal function are included, such as chloroquine and hydroxychloroquine, vigabatrin, deferoxamine, ethambutol, interferon-α, tamoxifen, digoxin, sildenafil, canthaxanthin, amiodarone and nefazodone. The role of mfERG in the early diagnosis of retinal toxicity and the evaluation of disease severity is reviewed, as well as its clinical value in monitoring disease progression or recovery after drug cessation.

Fixation stability and implication for multifocal electroretinography in patients with neovascular age-related macular degeneration after anti-VEGF treatment

PURPOSE

To quantify fixation stability in patients with neovascular age-related macular degeneration (nAMD) at baseline, 3 and 6 months after anti-vascular endothelial growth factor (anti-VEGF) treatment and furthermore asses the implications of an unsteady fixation for multifocal electroretinography (mfERG) measurements.

METHODS

Fifty eyes of 50 nAMD patients receiving intravitreal anti-VEGF treatment with either bevacizumab or ranibizumab and eight eyes of eight control subjects were included. Fixation stability measurements were performed with the Eye-Link eyetracking system and the retinal area in degrees² (deg²) containing the 68 % most frequently used fixation points (RAF68) was calculated. MfERG P1 amplitude and implicit time were analyzed in six concentric rings and as a summed response. Patients were examined at baseline, 3 and 6 months. Four different mfERG recordings were performed for the control subjects to mimic an involuntary unstable fixation: normal central fixation, 2.4°, 4.8°, and 7.1° fixation instability.

RESULTS

For control subjects, a fixation instability of 2.4° (corresponding to the central hexagon) did not reduce mfERG ring amplitudes significantly, whereas 4.8° and 7.1° fixation instability reduced the amplitudes significantly in rings 1 and 2 (p < 0.001) as well as in the peripheral rings in the 7.1° instability condition (p < 0.001). Fixation stability improved non-significantly for patients at 3 and 6 months. The size of the retinal area of fixation was at baseline, 3 and 6 months negatively correlated to visual acuity (VA) (r_baseline = -0.65, r_{3 months} = -0.60, and r_{6 months} = -0.66 respectively, p < 0.001) and mfERG amplitudes of the three innermost rings (r_baseline = -0.29, p = 0.042, r_3 months = -0.43, p = 0.003 and r_6 months = -0.31, p = 0.042). The VA cutoff for a fixation area less than 5 deg² (approximately the central hexagon) was 65, 77, and 68 ETDRS letters (corresponding a maximal Snellen equivalent of 0.31) at baseline, 3 and 6 months, respectively.

CONCLUSIONS

MfERG amplitudes in recordings of nAMD patients are at substantial risk of being reduced due to poor fixation as a large number of patients may use a fixation area of more than 5 deg². Fixation monitoring during recording as well as interpretation of results should be performed with care, especially in patients with poor visual acuity.

Chloroquine and beyond: exploring anti-rheumatic drugs to reduce immune hyperactivation in HIV/AIDS

The restoration of the immune system prompted by antiretroviral therapy (ART) has allowed drastically reducing the mortality and morbidity of HIV infection. However, one main source of clinical concern is the persistence of immune hyperactivation in individuals under ART. Chronically enhanced levels of T-cell activation are associated with several deleterious effects which lead to faster disease progression and slower CD4⁺ T-cell recovery during ART. In this article, we discuss the rationale, and review the results, of the use of antimalarial quinolines, such as chloroquine and its derivative hydroxychloroquine, to counteract immune activation in HIV infection. Despite the promising results of several pilot trials, the most recent clinical data indicate that antimalarial quinolines are unlikely to exert a marked beneficial effect on immune activation. Alternative approaches will likely be required to reproducibly decrease immune activation in the setting of HIV infection. If the quinoline-based strategies should nevertheless be pursued in future studies, particular care must be devoted to the dosage selection, in order to maximize the chances to obtain effective in vivo drug concentrations.

Multifocal ERG Guiding Therapy in a Case of Hydroxychloroquine Premaculopathy

We report the case of a 28-year-old female treated for systemic lupus erythematosus with hydroxychloroquine (200 mg/day) for 11 years. She was visually asymptomatic, with normal fundus appearance, normal colour vision testing findings, 20/20 visual acuity in both eyes, and only mild central bilateral defects on 10-2 perimetry. Multifocal electroretinography (mfERG) showed low density values for ring 1 in both eyes. Because the patient had not previously responded to alternative treatments and in consultation with her physician, the hydroxychloroquine dose was reduced to 200 mg four days/week. Four serial mfERGs performed at 4, 18, 25, and 34 months after dose reduction showed a progressive improvement in the definition and density of the responses until they were normalized at the third mfERG (25 months after hydroxychloroquine dose reduction). The fourth and final mfERG at 34 months confirmed the recovery in both eyes. Perimetry defects were mostly normalized. These results demonstrate the importance of mfERG for the safe management of patients under long-term hydroxychloroquine treatment.