CONTRAST SENSITIVITY AND VISUAL-ACUITY IN PATIENTS WITH EARLY CATARACTS

In a population of 188 nondiabetic patients with early cataracts or nu clear brunescence, we assessed the degree to which contrast sensitivit y function (CSF) provided more information about a patient's visual di sability than high contrast visual acuity measurements. Data collected included LOCS II cataract classification, Bailey-Lovie visual acuity (LogMAR score), Lotmar interferometric visual acuity (LI VA), and dist ance contrast sensitivity function (CSF) using the Vistech 6500. Gener alized least squares regression models in which CS was the dependent v ariable and either LogMAR score or LI VA was among the independent var iables were used to ascertain whether CSF provided additional informat ion about visual disability to that provided by LogMAR score or LI VA. Contrast sensitivity function was decreased only by nuclear opalescen ce at high frequencies (1 2 to 18 cpd); for all other cataract types a nd nuclear color, CSF testing provided no more information about catar act-related visual loss than LI VA or LogMAR score. Measurement of CSF using the Vistech 6500 system in patients with early cataracts provid es information on visual dysfunction beyond that provided by LogMAR sc ore or LI VA only in patients with nuclear opalescence, and that may n ot be clinically significant.