Measurement of glare sensitivity in cataract patients using low-contrast letter charts.
The Committee on Ophthalmic Procedures Assessment of the American Academy of Ophthalmology suggested using low-contrast visual acuity measured before and after adding a glare source as a test for assessing overall visual disability from immature cataracts. We have developed a test that follows the Committee's three principles of design, and we report that the effect of glare on visual acuity is considerably greater for recognizing low-contrast letters than for recognizing high-contrast letters. The effect of glare on visual acuity increases progressively as letter contrast is reduced in the stages 96%, 50%, 25%, 11% and 4%. The 25% chart (and possibly the 11% chart) gives the most suitable sensitivity for eyes with immature cataracts. Age-related brunescence and aging itself do not necessarily produce high sensitivity to glare. Sensitivity to glare was markedly different in eyes with different kinds of cataract.
Regan
D
D
Department of Ophthalmology, Toronto Hospital (Toronto Western Division), Ontario, Canada.
Giaschi
D E
DE
Fresco
B B
BB
D000368:Aged; D002386:Cataract / Q000503:physiopathology*; D015350:Contrast Sensitivity / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D012542:Scattering, Radiation; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology*