Determination of metric values and the ocular dioptric power of intraocular lens in capuchin (Cebus Apella)

Abstract

Cataract is an ophthalmic condition in several species and can be considered a major cause of visual impairment. Cataracts can be defined as the opacity of the lens or their capsule, due to changes in the lamellar architecture of fibers or capsule (BARNETT, 1985; JOHNSON & MILLER, 1990; GLOVER & CONSTANTINESCU, 1997; GELATT, 2007). Various causes have been implicated cataract, however, in most cases, this is still unknown (BARNETT, 1985). A cataract is an important ocular disease, whose treatment is surgery, but the loss of the lens results in sever hypermetropia with consequent impairment of vision (SAMPAIO et al, 2002). The correction of high hypermetropia and obtaining more accurate view are possible through the implantation of intraocular lens (IOL) to replace the extracted lens (GAIDDON et al., 1991). IOLs have their dioptric power calculated from the axial length eye and corneal curvature (keratometry) (MONTEIRO & ALLEMAN, 2001). The present study aims to determine the dimensions of the bulb of eye, the corneal curvature, and the lens dioptric power in monkeys (Cebus Apella) in order to characterize the metric of the visual system of this brazilian primate. Limited information from the literature urged to establish the physiological reference values, essential for calculating the dioptric power of intraocular lens to be implanted in this species, aiming at the correction of hypermetropia induced by removal of the lens with cataract; moreover, provide information for evaluating treatments intraocular lens or lens materials, to reduce the posterior capsule opacification, frequent surgical complication after cataract surgery in humans.