Contrast sensitivity in benign intracranial hypertension

Abstract

A study was undertaken to assess contrast sensitivity impairment in patients with benign intracranial hypertension (BIH) and to determine if contrast sensitivity provides more information about visual dysfunction than Snellen visual acuity. A computer-based system was used to measure spatial contrast sensitivity for chromatic and luminance stimuli at 1,4, and 16 cycles per degree (c/deg). The results from 26 eyes of 15 patients with BIH were compared with those of a control group matched for age and visual acuity. The visual acuity in the BIH group was normal (6/6 or better) in 22 eyes (85%) and slightly reduced (6/9) in the remaining four eyes (15%). Contrast sensitivity was significantly reduced in the BIH group at all spatial frequencies both for chromatic and luminance measures. In addition, there was a significantly greater loss of luminance compared to chromatic contrast sensitivity at low spatial frequency (1 c/deg). Contrast sensitivity measures are more sensitive than Snellen visual acuity in assessing BIH-related visual loss and may be of value in the initial assessment and follow-up of these patients.

Key Words:

• Benign intracranial hypertension
• contrast sensitivity
• optic disc oedema
• visual acuity
• chromatic
• luminance