Grating Visual Acuity in phakic, aphakic, and pseudophakic Poodles.

Objective To compare the grating visual acuity (VA) measured by visual evoked potentials (VEP) in phakic, aphakic, and pseudophakic Poodles. Animals studied Thirty-six Poodle dogs aged from 4 to 14 years. Procedures Animals were allocated into three different groups according to their lens status: phakic group (n = 12), aphakic group (n = 12), and pseudophakic group (n = 12). Grating VA was measured in cycles/degree (cpd) in all animals using the electrodiagnosis system Roland RETIport(R)in a dark room without using any mydriatic, sedative, or anesthetic drugs. Results The mean grating VA in the phakic, aphakic, and pseudophakic groups was 5.9 +/- 1.0 cpd (20/102-Snellen equivalent), 2.6 +/- 0.7 cpd (20/231), and 5.2 +/- 1.1 cpd (20/116), respectively. The VA from aphakic eyes was significantly lower when compared to the phakic and pseudophakic eyes (P < .05). There was no significant difference in VA between phakic and pseudophakic eyes. Conclusions The VEP is a useful tool for the evaluation of grating visual acuity in canines. The study showed that IOL implantation following phacoemulsification results in improved VA as measured by VEP compared to that of the aphakic eye and resulted in VA that was similar to that of the normal eye.