Retinal Evaluation Of Patients With Diffuse Unilateral Subacute Neuroretinitis Before And After Albendazole Therapy: Electrophysiology And Optical Coherence Tomography Findings

Abstract

Purpose: : To evaluate retinal morphology and electrophysiology in patients with diffuse unilateral subacute neuroretinitis (DUSN) before and after albendazole therapy.

Methods: : Five patients (8, 13, 19, 23, and 24 years old) diagnosed with DUSN based on fundus features were evaluated before and after treatment with albendazole. Patients with other possible causes of visual dysfunction were excluded. Treatment: albendazole 400 mg, 12/12 h, 10 days. Retinal morphology was analyzed using Optical Coherence Tomography (Stratus OCT - 3.0, Carl Zeiss Meditec) with scan type Fast Macular Thickness Map (6 mm). Retinal function was evaluated with full-field electroretinography (ffERG, scotopic and photopic protocols) and multifocal electroretinography (mfERG, 103 hexagons protocol) (VERIS). The healthy eye was used as the control for the electrophysiological analysis.

Results: : Before treatment, patients had signs of active disease: mild vitritis (+ / 4 +), pale optic disc, arteriolar narrowing, and several whitish spots in the retinal periphery. After treatment, patients showed signs of chronical disease: absence of vitritis, pale optic disc, arteriolar narrowing, and several dark spots of retinal pigment epithelial hypertrophy in the periphery. All patients showed improvement in visual acuity: logMAR, before treatment = 0.86 ± 0.4; after treatment = 0.35 ± 0.3. OCT showed decreased of retinal thickness and straightening of the foveal depression before albendazole treatment. Before treatment ffERG responses had statistical difference only to implicit time of scotopic b-wave, which was longer after treatment. mfERG showed no differences in N1 and P1 amplitudes and implicit times before and after treatment or in comparison with controls.

Conclusions: : The use of albendazole for DUSN treatment seems to improve visual acuity one month after medication, despite of morphological and scotopic implicit time changes in the retina.

Keywords: retinitis • electroretinography: clinical • antibiotics/antifungals/antiparasitics