Contrast sensitivity in macular degeneration and the relation to subjective visual impairment

Contrast sensitivity was determined with electronic and computer equipment (Cadwell CTS 5000) and with optotype test charts (LH low contrast test) in 31 patients, aged 47-89, with macular degeneration, mostly of the age-related type. Values of maximal sensitivity and mean sensitivity in different spatial frequency bands were estimated. Visual acuity at distance and the magnification factor needed for reading were also determined. Each of these measures were correlated with a score obtained in a subjective evaluation of difficulties with visual discrimination and orientation. It was found that poor visual discrimination and orientation was better correlated with low contrast sensitivity than with low visual acuity. The outcome of the LH-test was a better predictor of orientation problems than the electronic test.