Abstract
Abstract: :
Purpose: to observe the chronic effects of hydroxychloroquine on retinal electrical activity by multifocal electroretinogram (mERG) and evaluate the regional variance of retinal dysfunction in hydroxychloroquine retinopathy. Methods: mERG with 103 hexagons stimulation was performed in 6 patients (12 eyes) treated for systemic lupus erythematosus or rheumatoid arthritis with hydroxychloroquine. The daily dosages were from 200 to 400 mg/day. The periods of treatment were from 0 year to 17 years. The lifetime dosages were from 0 to 2.482 kgs. The amplitudes and latencies of the first-order kernel of mERGs were analyzed ring by ring with different eccentricities from center to periphery. Results: Four patients (8 eyes) had normal mERG who had lifetime dosage from 0 to 2 kgs. Two patients (4 eyes) had abnormal mERG. In these 2 patients, one patient (2 eyes) had attenuated response densities in a ring area of 2.2 to 14 degrees in diameter (Figure), and her visual acuities were 20/40 (od) and 20/30 (os); another one (2 eyes) had attenuated response densities in the whole tested field (45 degrees in diameter), and her visual acuities were 20/30 (od) and 20/30 (os). The first patient had lifetime dosage of 1.095 kgs (7.5 years). The second patient had lifetime dosage of 2.482 kgs (17 years). These 2 patients had normal appearance of the fundus, normal fluorescent angiography and normal visual field. Conclusion: Only in a small number of patients who have used high lifetime dosage of hydroxychloroquine may develop hydroxychloroquine retinopathy. Hydroxychloroquine retinopathy presents characteristic variations in mERG. mERG responses may be more sensitive for retinal function changes compared to visual acuity, color vision testing, Amsler grid testing or perimetry. mERG is also an objective method to follow these patients over the long term. We suggest mERG testing in all patients with a large lifetime dose of the hydroxychloroquine.
Keywords: 393 electrophysiology: clinical • 554 retina