Psychophysical impact and optical and morphological characteristics of symptomatic non-advanced cataract

Abstract

To investigate whether psychophysical, morphological, and/or optical characteristics of symptomatic non-advanced cataract are complementary to, or more appropriate than, visual acuity (VA) for the purposes of recording visual data that reflect subjective visual difficulty in patients with cataract that exhibit relative sparing of high contrast acuity (0.4 logarithm of minimal angle of resolution (logMAR) scale or better). Eighty-two patients with symptomatic non-advanced cataract and no other ocular pathology were asked to complete a validated questionnaire, and to perform a series of visual function assessments including: corrected distance VA (CDVA); photopic and mesopic contrast sensitivity; photopic and mesopic glare disability (GD); reading acuity and reading speed; stereoacuity; and retinal sensitivity. Optical and morphological characteristics of the cataract were evaluated by lens optical density and by the Lens Opacities Classification System III, respectively. Correlations between questionnaire score and each of these measures were calculated. Statistically significant negative correlations were observed between the Rasch-scaled questionnaire score and mesopic GD (at 3 and 6 cycles per degree (cpd); r=-0.396 (P<0.01) and -0.451 (P<0.05), respectively) and between the Rasch-scaled questionnaire score and photopic GD (at 3 and 6 cpd; r=-0.328 (P<0.01) and -0.440 (P<0.01), respectively). Symptomatic non-advanced cataract, in the presence of good CDVA, is associated with measurable subjective visual difficulty, best reflected in a decrease in mesopic and photopic GD (at medium spatial frequencies). CDVA does not reflect the patient's visual dissatisfaction in such cases.