New instrument for objective density measurement of the crystalline lens nucleus: correlation of visual acuity with nuclear density

Objective evaluation of nuclear cataracts would facilitate clinical activities and research studies. This presentation describes a new device using a helium-neon laser beam configured as a sheet of light. Computerized equipment was used for imaging and objective analysis of the lens nucleus. Visual acuity and density measurements of the crystalline lens nucleus were compared in 262 eyes. These included normals and patients with nuclear sclerosis or nuclear cataracts without other visually significant pathology. The coefficient of correlation between acuity and mean nuclear density was 0.78. Thirty-two eyes were examined twice and had no change in visual acuity between the two visits. These paired density measurements had a correlation coefficient of 0.96. Fifteen patients who did have decreased acuity between the two examinations had a correlation between the two measurements of 0.33. The intensity of nuclear sclerosis or cataract, as well as density changes, can be objectively measured and correlated to visual acuity degradation with this instrument.