Refractive keratoplasty: myopic keratomileusis in baboons.

We performed 8 myopic keratomileusis procedures in a baboon (Papio cynocephalus) model using the same instruments and techniques which are presently clinically employed. We requested 10 diopters of refractive correction and were able to achieve a mean keratometric correction of 5.5 diopters (range 2.4-8.4) in 6 eyes. Keratometric data in the two remaining eyes was not obtained, because of distortion of corneascope photographs. We did not encounter any technical problems at surgery or during the 2-1/2 to 6 month postoperative period of followup. Morphologic analysis demonstrated subclinical, focal breaks in Bowman's membrane in all specimens and keratocyte repopulation in 7 of 8 eyes. We did find a wide range in the central thickness of the excised corneas which can account for the undercorrections achieved. We consider the baboon model to be excellent for the evaluation of myopic keratomileusis.