Retinal nerve fibre layer thickness measurements in patients using chloroquine

The assessment of structural and functional test results for early detection of hydroxychloroquine macular toxicity

PURPOSE

To assess structural (optical coherence tomography, fundus autofluorescence) and functional (contrast sensitivity and visual field) test results which were used for detecting early retinal changes in patients using oral hydroxychloroquine.

METHODS

Patients using oral hydroxychloroquine for at least one year were divided into two groups according to the duration of drug use. Groups 1 and 2 consisted of patients with drug use for more than 5 years and 1-5 years, respectively. The drug-using groups were compared with the control group. The mean retinal nerve fiber layer (RNFL), central macular thickness (CMT), ganglion cell-inner plexiform layer (GC-IPL), static 10-2 visual field, fundus autofluorescence (FAF) imaging, and contrast sensitivity tests were performed and statistically compared between groups.

RESULTS

Median and temporal quadrant RNFL thicknesses were found to be statistically significantly lower in the drug groups. In the drug groups, the GC-IPL sectoral and mean thicknesses were found to be statistically lower in all quadrants. Central macular thickness was also found to be similar in all three groups. There was no significant difference between the groups in visual field parameters. Macular FAF images were significantly higher in the drug users, but there was no significant difference between the three groups in foveal FAF images. Contrast sensitivity measurements were significantly lower in the drug groups than in the control group at all spatial frequencies except 6 and 18 cycles/degree.

CONCLUSIONS

The combined use of structural and functional tests in patients using hydroxychloroquine provides useful information in detecting early retinal changes.

The Impact of Systemic Medications on Retinal Function

This study will provide a thorough review of systemic (and select intravitreal) medications, along with illicit drugs that are capable of causing various patterns of retinal toxicity. The diagnosis is established by taking a thorough medication and drug history, and then by pattern recognition of the clinical retinal changes and multimodal imaging features. Examples of all of these types of toxicity will be thoroughly reviewed, including agents that cause retinal pigment epithelial disruption (hydroxychloroquine, thioridazine, pentosan polysulfate sodium, dideoxyinosine), retinal vascular occlusion (quinine, oral contraceptives), cystoid macular edema/retinal edema (nicotinic acid, sulfa-containing medications, taxels, glitazones), crystalline deposition (tamoxifen, canthaxanthin, methoxyflurane), uveitis, miscellaneous, and subjective visual symptoms (digoxin, sildenafil). The impact of newer chemotherapeutics and immunotherapeutics (tyrosine kinase inhibitor, mitogen-activated protein kinase kinase, checkpoint, anaplastic lymphoma kinase, extracellular signal-regulated kinase inhibitors, and others), will also be thoroughly reviewed. The mechanism of action will be explored in detail when known. When applicable, preventive measures will be discussed, and treatment will be reviewed. Illicit drugs (cannabinoids, cocaine, heroin, methamphetamine, alkyl nitrite), will also be reviewed in terms of the potential impact on retinal function.

Macular Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer Thicknesses in Hydroxychloroquine Retinopathy

OBJECTIVE

To investigate macular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (RNFL) thicknesses in patients with hydroxychloroquine retinopathy of differing severity.

DESIGN

Cross-sectional, case-control comparison study.

PARTICIPANTS

From patients screened for hydroxychloroquine retinopathy between January 2016 and October 2021 using swept-source optical coherence tomography (SS-OCT), fundus autofluorescence (FAF), and standard automated perimetry, 66 patients with retinopathy and 66 without retinopathy were included by 1:1 propensity score matching based on age, sex, systemic diseases, history of tamoxifen and pentosan use, and kidney disease.

METHODS

Eyes with hydroxychloroquine retinopathy were divided into early, moderate, and severe stages. Inner-retinal thickness parameters, including macular GCC (RNFL + ganglion cell layer + inner plexiform layer) and peripapillary RNFL thicknesses, were automatically obtained using SS-OCT (DRI-OCT Triton, Topcon Inc., Japan) and compared between patients with and without retinopathy and between severity subgroups. The structure-function relationships between GCC or peripapillary RNFL thicknesses and perimetric parameters including mean deviation (MD) and visual field index (VFI) of Humphrey 30-2 test were evaluated.

MAIN OUTCOME MEASURES

Macular GCC and peripapillary RNFL thickness parameters.

RESULTS

The average macular GCC and peripapillary RNFL thicknesses were significantly decreased in patients with hydroxychloroquine retinopathy relative to those without retinopathy. Macular GCC thicknesses in 4 of 6 macular sectors and peripapillary RNFL thicknesses in 9 of 12 clock-hour sectors were significantly different between the groups. The differences in the average and sectoral macular GCC parameters were statistically significant among the severity subgroups, particularly between severe and earlier stages. Average macular GCC and peripapillary RNFL thicknesses significantly correlated with MD and VFI in all patients (all P < .001).

CONCLUSIONS

Macular GCC and peripapillary RNFL thinning was more prominent in eyes with severe hydroxychloroquine retinopathy, as indicative of inner-retinal thinning in eyes with advanced-stage disease. Further, as inner-retinal thinning showed a significant correlation with worse perimetric function, cautious evaluation of the inner retina may be required for eyes with advanced hydroxychloroquine retinopathy.

Systemic toxicity of chloroquine and hydroxychloroquine: prevalence, mechanisms, risk factors, prognostic and screening possibilities

Chloroquine (CQ) and its hydroxylated analog, hydroxychloroquine (HCQ), are 4-aminoquinoline initially used as an antimalarial treatment. CQ and HCQ (4-aminoquinoline, 4-AQ) are today used in rheumatology, especially to treat rheumatoid arthritis and systemic lupus erythematosus. Their mechanism of action revolves around a singular triptych: 4-AQ acts as alkalizing agents, ionized amphiphilic molecules, and by binding to numerous targets. 4-AQ have so pleiotropic and original mechanisms of action, providing them an effect at the heart of the regulation of several physiological functions. However, this broad spectrum of action is also at the origin of various and original side effects, notably a remarkable chronic systemic toxicity. We describe here the 4-AQ-induced lesions on the eye, the heart, muscle, the nerves, the inner ear, and the kidney. We also describe their prevalence, their pathophysiological mechanisms, their risk factors, their potential severity, and the means to detect them early. Most of these side effects are reversible if treatment is stopped promptly. This 4-AQ-induced toxicity must be known to prescribing physicians, to closely monitor its appearance and stop treatment in time if necessary.

Peripapillary Retinal Nerve Fiber Layer Thicknesses Did Not Change in Long-term Hydroxychloroquine Users

Purpose

To evaluate changes in the peripapillary retinal nerve fiber layer (RNFL) thicknesses using spectral-domain optical coherence tomography (SD-OCT) in hydroxychloroquine (HCQ) users.

Methods

The medical records of HCQ users were retrospectively reviewed. In these HCQ users, an automated perimetry, fundus autofluorescence photography, and SD-OCT with peripapillary RNFL thickness measurements were performed. The peripapillary RNFL thicknesses were compared between the HCQ users and the control groups. The relationships between the RNFL thicknesses and the duration or cumulative dosage of HCQ use were analyzed.

Results

This study included 77 HCQ users and 20 normal controls. The mean duration of HCQ usage was 63.6 ± 38.4 months, and the cumulative dose of HCQ was 528.1 ± 3.44 g. Six patients developed HCQ retinopathy. Global and six sectoral RNFL thicknesses of the HCQ users did not significantly decrease compared to those of the normal controls. No significant correlation was found between the RNFL thickness and the duration of use or cumulative dose. The eyes of those with HCQ retinopathy had temporal peripapillary RNFL thicknesses significantly greater than that of normal controls.

Conclusions

The peripapillary RNFL thicknesses did not change in the HCQ users and did not correlate with the duration of HCQ use or cumulative doses of HCQ. RNFL thickness is not a useful biomarker for the early detection of HCQ retinal toxicity.

Treating lupus patients with antimalarials: analysis of safety profile in a single-center cohort

This longitudinal retrospective study aims at describing the safety profile and the reasons for discontinuation of antimalarials in patients with systemic lupus erythematosus (SLE) and discoid lupus erythematosus (DLE), focusing on ocular toxicity. We analyzed the clinical data of 845 SLE and DLE patients; 59% of them were taking antimalarials: 1.4% chloroquine (CQ), 88.5% hydroxychloroquine (HCQ) and 10.1% both. The mean therapy duration was 82.5 ± 77.4 months. At least one side effect was reported by 19.4% of patients, leading to temporary or permanent withdrawal in 9.1% and 10.3% of cases, respectively; 19.3% of patients experienced side effects with HCQ and 8.6% with CQ. In 55.1% of cases, the adverse event was mild or moderate. Ophthalmological alterations were reported by 8.5% but were confirmed by the ophthalmological examination in 5.5% of cases. Retinal alterations were associated with age, disease duration and duration of the antimalarial therapy, but not to drug dose and comorbidities or lupus nephritis. This is the largest monocentric longitudinal study confirming the good safety profile of antimalarials in DLE and SLE patients. The main adverse events during the therapy were mild or moderate, but maculopathy—reported in a low percentage of patients—remains the main cause of treatment withdrawal.

Macular ganglion cell-inner plexiform layer thickness for detection of early retinal toxicity of hydroxychloroquine

PURPOSE

This study evaluated the macular ganglion cell-inner plexiform layer (GC-IPL) thickness using spectral-domain (SD) optical coherence tomography (OCT) in patients with chronic exposure to hydroxychloroquine (HCQ).

METHODS

A total of 90 patients (90 eyes) treated with HCQ for at least 5 years and normal controls were included in the study. A fundus examination, automated threshold perimetry, and GC-IPL thickness measurements using the Cirrus high-definition OCT ganglion cell analysis algorithm were performed in all patients treated with HCQ. Average, minimum, and sectorial macular GC-IPL thicknesses were compared between the patients and controls.

RESULTS

There was no statistically significant difference in age or sex between the groups. The anterior segment and fundoscopy were normal in all patients and controls. Visual field (VF) testing was normal in all patients. The average, minimum, and sectorial macular GC-IPL thicknesses were significantly lower in patients than those in control subjects.

CONCLUSIONS

There was significant thinning of the macular GC-IPL in the absence of clinically evident HCQ-related retinopathy and VF abnormalities. Measurements of the macular GC-IPL thickness using SD-OCT may therefore be useful in the early diagnosis and in monitoring the progression of retinal changes in patients receiving long-term HCQ therapy.

Analysis of Clinical Factors Associated with Retinal Morphological Changes in Patients with Primary Sjögren's Syndrome

Purpose

To investigate clinical factors associated with abnormal retinal morphologies in patients with primary Sjögren's syndrome (pSS).

Methods

One-hundred-thirty patients with pSS who underwent immunoserological tests, minor salivary gland biopsies, and optical coherence tomography examinations were retrospectively analyzed. Risk factors for abnormally reduced peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell–inner plexiform layer (mGCIPL) thicknesses were evaluated, as well as the correlation between clinical factors and pRNFL and mGCIPL thicknesses.

Results

Anti-Sjögren's syndrome type B (SSB) antibody positivity (P = 0.048) was identified as a risk factor associated with abnormally reduced pRNFL thickness, and anti-SSB positivity (P = 0.005) and erythrocyte sedimentation rate (ESR) level (P = 0.031) were identified as risk factors associated with an abnormally reduced mGCIPL thickness as revealed by multivariate logistic regression analysis. There was a significant negative correlation between anti-SSB antibody levels and the thickness of pRNFL and mGCIPL. The thicknesses of pRNFL and mGCIPL were significantly reduced in anti-SSB–positive eyes when compared to anti-SSB–negative eyes (P < 0.05). However, histopathologic grading was not associated with the pRNFL and mGCIPL thicknesses.

Conclusion

Anti-SSB antibody positivity and ESR levels may be useful for predicting an abnormally reduced pRNFL or mGCIPL thickness in patients with pSS. Our results may provide clinical evidence to substantiate the association between aberrant autoimmunity and inner retinal changes in patients with pSS.

Retinal functional changes measured by frequency-doubling technology in patients treated with hydroxychloroquine

BACKGROUND

Antimalarial drugs such as chloroquine (CQ) and hydroxychloroquine (HCQ) are mainly used in the treatment of rheumatologic diseases, and their use may be associated with irreversible retinal toxicity. Previous studies indicate early paracentral visual field loss (Humphrey 10-2) in patients taking HCQ". These paracentral defects appear before changes in other clinical parameters as visual acuity and fundoscopy. The mechanism of CQ toxicity remains unclear. It was reported that toxic doses of CQ administered for as long as 4.5 years to Rhesus monkeys caused an initial dramatic effect on ganglion cells, followed later by photoreceptors and RPE degeneration. The purpose of this study is to explore early retinal functional changes measured by frequency-doubling technology (FDT) in patients treated with hydroxychloroquine (HCQ).

METHODS

Forty-eight eyes of 48 subjects treated with hydroxychloroquine (HCQ), with no signs of retinal toxicity, and 36 eyes of 36 age and sex-matched healthy subjects were enrolled in this cross-sectional, prospective, observational, case control study. Functional testing included frequency-doubling Humphrey-matrix perimetry (FDP), white-on-white Humphrey visual field perimetry (HFA), using the 24-2 and 10-2 threshold programs, multifocal electroretinogram (mfERG, Veris 4.9) and low contrast sensitivity (CS) measurement.

RESULTS

FDP mean deviation (MD) was found to be significantly reduced in HCQ-treated patients compared to controls both in the 24-2 (-1.38 ± 2.41 dB vs 0.21 ± 1.83 dB, p < 0.01) and in the 10-2 program (-0.97 ± 2.88 dB vs 0.15 ± 1.72 dB, p < 0.01). FDP pattern standard deviation (PSD) was found to be significantly worse in HCQ-treated patients compared to controls both in the 24-2 (2.70 ± 0.65 dB vs 2.41 ± 0.31 dB, p < 0.01 and in the 10-2 program (2.86 ± 0.48 dB vs 2.48 ± 0.39 dB, p < 0.01). HFA PSD and CS was also significantly reduced in HCQ patients, while response amplitude densities (RAD) were similar between patients and controls. A statistically significant difference in the ratio of the 5°-10° RAD and the 0°-2.5° RAD (0.31 ± 0.08 vs 0.36 ± 0.07 respectively, p < 0.05) was found between groups.

CONCLUSION

Frequency doubling perimetry could be useful to detect early retinal impairment in patients treated with hydroxychloroquine.

Ocular fundus manifestation of two patients following long-term chloroquine therapy: a case report

This report describes the typical manifestations of chloroquine retinopathy with some advanced new technology. A series of examinations were performed on the patients, including the fundus fluorescein angiography, optical coherence tomography, GDxVCC Nerve Fiber Analyzer, full-field electroretinography, multifocal electroretinography and visual field examinations, to provide a better understanding of chloroquine retinopathy.

Characterization of the phospholipidogenic potential of 4(1H)-pyridone antimalarial derivatives

Drug-induced phospholipidosis (PLD) is characterized by the excessive accumulation of phospholipids in lysosomes. It is accompanied by intracellular retention of drug that could be associated with increased cytotoxicity. Drug-induced PLD is recognized as a significant challenge for drug development, depending on the severity of the effect it could be reversible or caused cell death. Therefore, the identification at early stages of drug discovery of the potential to induce PLD can be advantageous for selecting improved development candidates. PLD has commonly been associated with cationic amphiphilic drugs (CADs) composed by a hydrophobic ring structure and a hydrophilic side chain with a charged amine group. 4(1H)-pyridone derivatives are a family of antimalarial agents that act as potent selective inhibitors of Plasmodium falciparum mitochondrial function and according to their chemical structure might be considered to be CADs. In the present study, the potential of 4(1H)-pyridone derivatives to induce PLD in vitro and their general cytotoxicity properties were investigated. A cell-based fluorescence assay using the fluorescent phospholipid probe NBD-PE [N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine, triethylammonium salt] was established. Five PLD-inducing reference compounds and six negative reference compounds were evaluated in vitro in HepG2 cell line. The pyridones tested were ranked by using a chloroquine-equivalent scale (chloroquine constituting a well-known antimalarial drug that acts as a potent inducer of lysosomal storage of phospholipids in both cell cultures and in vivo studies). The present findings indicate that these novel chemical antimalarial compounds are not PLD inducers despite to be considered structurally as CADs. Furthermore, none of the compounds tested showed significant cytotoxicity at their maximum solubility.

Optical coherence tomography in a patient with chloroquine-induced maculopathy

We herein report the optical coherence tomography (OCT) findings in a case of chloroquine-induced macular toxicity, which to our knowledge, has so far not been reported. A 53- year-old lady on chloroquine for treatment of rheumatoid arthritis developed decrease in vision 36 months after initiation of the treatment. Clinical examination revealed evidence of retinal pigment epithelial (RPE) disturbances. Humphrey field analyzer (HFA), fundus fluorescein angiography (FFA) and OCT for retinal thickness and volume measurements at the parafoveal region were done. The HFA revealed bilateral superior paracentral scotomas, FFA demonstrated RPE loss and OCT revealed anatomical evidence of loss of ganglion cell layers, causing marked thinning of the macula and parafoveal region. Parafoveal retinal thickness and volume measurements may be early evidence of chloroquine toxicity, and OCT measurements as a part of chloroquine toxicity screening may be useful in early detection of chloroquine maculopathy.

Chloroquine retinopathy: lipofuscin- and melanin-related fundus autofluorescence, optical coherence tomography and multifocal electroretinography

PURPOSE

To evaluate melanin-related near-infrared fundus autofluorescence (NIA, excitation 787 nm, emission > 800 nm), lipofuscin-related fundus autofluorescence (FAF, excitation 488 nm, emission >500 nm), optical coherence tomography (OCT), and multifocal electroretinography (mfERG) in patients with chloroquine (CQ) retinopathy.

METHODS

Two patients with progressed CQ retinopathy underwent clinical examination, ISCEV mfERG evaluation, and FAF and NIA imaging using a confocal scanning laser ophthalmoscope (Heidelberg Retina Angiograph 2) with either a 30 degrees or wide-angle field-of-view. OCT3 imaging was performed in one of these patients.

RESULTS

In the foveola, FAF and NIA were relatively normal. Parafoveal loss of retinal pigment epithelium (RPE) was indicated by absent FAF and NIA. An area of reduced FAF and NIA surrounded the parafoveal region of RPE loss. In the adjacent area, FAF was increased and increased NIA marked the peripheral border of increased FAF. Wide-field imaging revealed increased FAF in association with retinal vessels. Retinal thickness was markedly reduced in the OCT predominantly in the parafoveal region. Visual field loss and mfERG amplitude reduction corresponded to areas with increased or reduced FAF and NIA.

CONCLUSION

Patterns of FAF and NIA indicate different stages of pathophysiologic processes involving lipofuscin and melanin in the RPE. Combined retinal imaging and functional testing provides further insights in the pathogenesis and development of retinal degenerative disease. An association of CQ retinopathy with retinal vessels architecture is hypothesized.