Visual Impairment in Dengue Feber: PERG and VECP Findings

Abstract

Abstract: : Purpose:The dengue fever is a tropical disease caused by a Flaviviridae and is transmitted by Aedes aegypti. There have been reports of ocular manifestations during the acute phase of the disease. We evaluated visual impairment associated with dengue fever using PERG and VECP recordings and extensive ophthalmologic investigation. Methods:Two female patients (TNM041027, 26 years–old; MGF041028, 56 years–old) had been evaluated and diagnosed with dengue fever by clinical evaluation and specific IgM antibodies. Both patients were submitted to extensive ophthalmologic and electrophysiological evaluation. The MGF041028 was submitted to vitrectomy due vitreous hemorrhage. Pattern electrorretinogram (PERG) and visual evoked cortical potential (VECP) were recorded using the ISCEV (International Society of Clinical Electrophysiology of Vision) recommended standards. The stimuli were isoluminant pattern reversal checkerboards, having spatial frequency of 0.5 and 2 cycles/degree. We measured PERG and VECP amplitude and latency and compared them with age–matched controls. Both eyes were separately tested. Results:The visual acuity was low, vision blurred for TNM041027 left eye and MGF041028 right eye. Fluorescein angiography was normal for both patients. Humphrey computerized campimetry indicates central scotomata for both eyes of TNM041027 and normal left eye for MGF041028. It was not possible to evaluate the right eye visual field for MGF041028 due to the profound lack of sensitivity. For TNM041027, P50 and N95 PERG components had lower amplitudes than normals for both eyes; latency was in the normal range. There was no response at 2 cycles/degree. The P100 and N135 VECP components were in the normal range for 0.5 cycles/degree, but their amplitude was decreased at 2 cycles/degree. For MGF041028, there was a pronounced decreased in the P50 and N95 PERG components at 0.5 cycles/degree for the left eye and no PERG response for the right eye. There was no response at 2 cycles/degree for both eyes. The P100 and N135 VECP components were in the normal range for 0.5 cycles/degree both eyes and 2 cycles/degree left eye, but there was no VECP response for the right eye. Conclusions:PERG and VECP findings suggest that rare ocular complications associated with dengue fever may result in permanent visual impairment. The more severe PERG findings in comparison with VECP findings are compatible with macular damage.

Keywords: electrophysiology: clinical • electroretinography: clinical