Refractive keratoplasty with hydrogel implants in primates.

Histological examination of primate corneas with hydrogel lenses implanted in intrastromal pockets showed the corneal lamella posterior to the implant protruding into the anterior chamber; these eyes had shown no increase in anterior corneal curvature. In an attempt to obtain a dioptric increase without removing a corneal lamella, relaxing incisions were made in Bowman's layer followed by intrastromal implantation of hydrogel lenses. However, no refractive increase resulted, although six of the seven eyes were optically clear eight months postoperatively.