A comparative study of the usefulness of color vision, photostress recovery time, and visual evoked potential tests in early detection of ocular toxicity from hydroxychloroquine
ABSTRACT Ocular toxicity from hydroxychloroquine (HCQ) is rare, but its potential permanence and severity makes it imperative to employ measures and screening protocols to minimize its occurrence. This study was performed to assess the usefulness of color vision, photo stress recovery time (PSRT), and visual evoked potentials (VEP) in early detection of ocular toxicity of HCQ, in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). 86 patients were included in the study and divided into three groups: (1) with history of HCQ use: interventional 1 (Int.1) without fundoscopic changes and Int.2 with fundoscopic changes; and (2) without history of HCQ use, as control. Visual field, color vision, PSRT and VEP results were recorded for all patients and the effect of age, disease duration, treatment duration and cumulative dose of HCQ on each test was assessed in each group. There was a significant relationship among PSRT and age, treatment duration, cumulative dose of HCQ and disease duration (P<0.001 for all). Color vision was normal in all the cases. P100 amplitude was not different between the three groups (P=0.846), but P100 latency was significantly different (P=0.025) and for Int.2 it was greater than the others. The percentage of abnormal visual fields for Int.2 was more than Int.1 and control groups (P=0.002 and P=0.005 respectively), but Int.1 and control groups were not significantly different (P>0.50). In the early stages of maculopathy, P100 latencies of VEP and PSRT are useful predictors of HCQ ocular toxicity. In patients without ocular symptoms and fundoscopic changes, the P100 latency of VEP predicts more precisely than the others.
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ABSTRACT: To summarize current technique, indications, and pitfalls of electrophysiologic testing used in ophthalmology. Visual evoked potentials (VEPs) may be useful as an objective measurement of refractive error in complicated patients. VEP P100 latency was found superior to color vision and visual field in early stages of hydroxychloroquine maculopathy. VEP results can be predictive of visual recovery in traumatic optic neuropathy. Multifocal electroretinogram (ERG) or VEP can provide an objective assessment of visual field defects not yet present on automated perimetry in patients with glaucomatous and nonglaucomatous optic neuropathies. In patients with intraocular lymphoma, reduced amplitudes of all ERG components can be recorded, with the b-wave amplitude being most significantly affected. Various visual electrophysiologic tests are useful to the ophthalmologist, each with different indications. The flash ERG is most useful in diffuse retinal disorders, whereas the multifocal ERG is superior in localized retinal disease. VEPs can be valuable in diagnosing optic neuropathies, nonorganic visual loss, and assessing visual function in infants or children.Current opinion in ophthalmology 11/2012; 23(6):497-505. DOI:10.1097/ICU.0b013e328359045e · 2.64 Impact Factor