Relative Afferent Pupillary Defect and Electroretinogram in Patients with Asymmetric Cataracts

ABSTRACT

PURPOSE: To investigate the incidence, associated factors, and the prognostic significance of relative afferent papillary defect (RAPD) in the eyes with less severe cataract and determine which mechanism of 'scattering' or 'dark adaptation' is more applicable, we evaluated 40 patients with asymmetric cataract (AC). METHODS: Forty patients of AC with the differences of three lines or more of visual acuity by Han's visual acuity chart underwent ophthalmic examinations including the 'swinging flashlight test' and electroretinogram before and after cataract surgery. RESULTS: There were nineteen patients who showed definite RAPD in the eyes with less severe cataract. The differences of log MAR between the two eyes were more than 1.55 or less than 0.73 in 17 patients (89.5%) with RAPD. Degree of posterior subcapsular opacity was marginally associated with RAPD in the eyes with less than 1.06 of log MAR differences. There was no association between the presence of RAPD and postoperative visual acuities. In the eyes with RAPD, b wave amplitudes tended to be smaller in the eyes with more severe cataract than those with less severe cataract before dark adaptation. However, after dark adaptation, b wave amplitudes tended to be larger in eyes with more severe cataract than those in the eyes with less severe cataract, and preoperatively than postoperatively. CONCLUSIONS: The incidence of RAPD of less severe cataract eye was significant (48%) but RAPD was not associated with visual acuity prognosis. The results of electroretinogram more favored 'scattering ' than 'dark adaptation' as the mechanism of RAPD phenomenon.