Phacoemulsification and implantation of foldable +14 diopter intraocular lenses in five mature horses

Presently, intraocular lenses (IOLs) are not routinely implanted after equine cataract surgery. Subsequently, horses are visual but markedly farsighted (hyperopic). This report describes the surgical results and visual status after phacoemulsification and implantation of IOLs in mature horses with spontaneous cataracts. Six eyes of 5 mature horses underwent phacoemulsification and implantation of a +14 diopter (D) foldable IOL. Recheck ocular examinations were performed at 1, 4 and 24 weeks post operatively. Refractive error was recorded at 4 weeks post operatively. Visual status, refractive error and anterior chamber depth were recorded 24 weeks post operatively: 5 of 6 operated eyes remained visual and the average refractive error was +0.4 ± 1.1D. There was a significant difference between the 24 week post operative refractive error and the population mean of +10D (P<0.0001) for aphakic horses. The average post operative anterior chamber depth was 7.89 ± 1.55 mm. One globe was enucleated 2 months post operatively. Phacoemulsification with IOL implantation resulted in a significant reduction in post operative refractive error and restored vision to within 0.4D of emmetropia in 5 of 6 operated eyes. Implantation of a +14D IOL ameliorated the hyperopia documented in aphakic horses and improved the post operative visual acuity.