Comparison of optotype contrast sensitivity and visual evoked potentials in optic nerve disease

Abstract

A prospective study was undertaken to compare optotype contrast sensitivity (OCS) chart performance with standard Snellen optotype acuity, and with pattern-reversal visual evoked potentials (PRVEP), to determine relative sensitivity for detecting and quantitating optic nerve disease, principally optic neuritis. Twenty-one eyes of 18 patients were assessed, 14 eyes with corrected Snellen acuity of 20/25 or better. Three OCS charts (Regan type) were used: a 95% contrast chart, which correlated well with Snellen acuity; and a 9% and 3% contrast chart. The latter best discriminated between recovered optic neuritis and normal controls, with no false-negatives and only three false-positives. The 3% low contrast chart was as sensitive as PRVEP in detecting visual dysfunction in recovered optic neuritis with near-normal visual acuity.

Key Words:

• contrast sensitivity
• optotype
• Snellen visual acuity
• visual evoked potentials
• optic nerve disease
• optic neuritis