Retina in rheumatic diseases: Standard full field and multifocal electroretinography in hydroxychloroquine retinal dysfunction

Abstract

Background:The purpose of this study was to evaluate and compare full-field electroretinography (ERG) and multifocal electroretinography (mfERG) results in detecting retinal dysfunction in a large number of asymptomatic patients treated with hydroxychloroquine (Hy). Methods: Fifty eyes in 50 patients with rheumatic diseases who had been using Hy for a period of time ranging from 30 months to 15 years, and 25 eyes in 25 healthy controls, were evaluated. Receiver operator characteristic (ROC) curves were calculated to determine the sensitivity and specificity of abnormal values in patients compared to the normal controls. Results: Signal depression was observed on the mfERG of Hy-treated patients. The most prevalent pattern was pericentral loss (19 eyes, 54.3 per cent), followed by full-field loss (11 eyes, 31.4 per cent), and central loss (five eyes, 14.3 per cent). Conversely, depression of the amplitude responses to the full field ERG was observed in only 16 per cent of the cases. The areas under the ROC curves ranged from 0.4056 to 0.9012, with the mfERG values having the largest areas, whereas the full-field ERG curves had the smallest area. The mfERG responses yielded the greatest sensitivity and specificity. In particular, the P1-N1 wave amplitude (ring 2) and root mean square (RMS) amplitude (ring 1) had specificities of 76 and 88 per cent, respectively, at sensitivities of 90 and 86 per cent. Conclusion: A statistically significant retinal functional impairment was demonstrated by mfERG in the central two to 10 degrees in Hy-treated patients. Therefore, mfERG may provide an objective measurement of retinal dysfunction in patients receiving Hy therapy. Key words: electroretinography, hydroxychloroquine, multifocal electroretinography, retinal toxicity, rheumatic diseasesThe most common uses of hydroxychloroquine sulphate (Hy) are in the management and prophylaxis of malarial fever, rheumatoid arthritis, lupus erythematosus, Sjögren syndrome, systemic vasculitis, and mixed connective tissue disease.1-3 Hy is in a class of drugs called antimalarials and has a prolonged half-life of up to 30 days in plasma and can persist for months after therapy.3-5 Side-effects may include ocular, gastrointestinal, dermatological, auditory, cardio-circulatory, haematological and neuromuscular alterations. Hy has a high affinity for binding to melanin granules and therefore tends to accumulate in the iris, choroid, ciliary body and retinal pigment epithelium (RPE). Atrophic, pigmentary retinal changes of the periphery and the macula (bull's eye), attenuated retinal vessels and optic atrophy may be seen in rare cases of chronic retinal toxicity. The symptoms include difficulty in reading, photophobia, blurred distance vision, The purpose of this study was to investigate and compare the results of electroretinography (ERG) and mfERG in a large cohort of Hy treated patients. We also aimed to ascertain whether this relatively new test might be used as a screening examination for patients under prolonged treatment with Hy and to ...

Assessment of hydroxychloroquine maculopathy after cessation of treatment: an optical coherence tomography and multifocal electroretinography study

“…Treatment withdrawal seems to result in improved retinal responses, affecting mainly their amplitudes, as we have also mentioned 20. Moreover, the sensitivity and specificity of mfERG appear greater compared to visual acuity and color vision testing, Amsler grid, and full-field ERG, especially in evaluating cone dysfunction 21,22. Reduced central retinal responses could be helpful in differentiating hydroxychloroquine-induced maculopathy from other retinal diseases such as age-related macular degeneration 22.…”

Therapy and pharmacological properties of hydroxychloroquine and chloroquine in treatment of systemic lupus erythematosus, rheumatoid arthritis and related diseases

“…Based on information in McChesney (1983); McChesney and Fitch (1984); Finbloom et al (1985); Edstein et al (1986); Salton (1987); Rynes (1988Rynes ( , 1992Rynes ( , 1997; Easterbrook (1990); Parke (1993) In recent years, there have been instrumental procedures devised to improve the detection of early stages of retinopathy. These include full-field and multifocal electroretinography (Tzekov 2005;Nebbioso et al 2011) and microperimetry (Martínez-Costa et al 2013). The latter technique has been found to lead to sensitive detection of retinal changes in the elderly who seem to be more prone to retinopathy (Martínez-Costa et al 2013).…”

Statistical guidelines for the analysis of data obtained from one or both eyes

“…If measurements are included from both eyes without consideration of their mutual correlation, there may be a significant effect on the results of the experiment . Third, there may be an advantage in using both eyes in a study, especially in an experimental context, as one eye may be used as a control for the other, rather than recruiting a separate control population . An experimental treatment can be applied in healthy subjects to one eye, selected at random (the treated eye), the other acting as a control.…”

“…4,5 Third, there may be an advantage in using both eyes in a study, especially in an experimental context, as one eye may be used as a control for the other, rather than recruiting a separate control population. 6,7 An experimental treatment can be applied in healthy subjects to one eye, selected at random (the treated eye), the other acting as a control. In addition, in diseases which are essentially monocular and the fellow eye essentially healthy, one eye can be regarded as the 'diseased' eye and the other the control.…”