Case reports of six patients having pre-existing corneal irregularities were prepared. They included patients with keratoconus, hexagonal keratotomy, corneal transplant, LASIK, ABMD and previous penetrating injury. Pre and postoperative refraction and topography were analyzed. All patients received biaspheric IOLs and some received corneal or limbal relaxing incisions at the time of the surgica...

PURPOSE To describe the presentation and clinical course of eyes with a history of radial keratotomy (RK) and varying degrees of endothelial degeneration. METHODS Retrospective case series were used. RESULTS Thirteen eyes (seven patients) were identified with clinical findings of significant guttata and a prior history of RK. The mean age of presentation for cornea evaluation was 54.3 years...

An experimental comparison of the ring-lens and the astigmatic techniques of generating a focus-error signal (FES) in optical disk systems reveals that the ring lens generates a FES curve over two times steeper than that produced by the astigmat. Partly because of this large slope and partly because of its diffraction-limited behavior, the ring-lens scheme exhibits superior performance characte...

PURPOSE To evaluate laser in situ keratomileusis (LASIK) for induced hyperopia after radial keratotomy. METHODS Twenty eyes had LASEK for induced hyperopia after radial keratotomy. All eyes were treated using the Nidek excimer laser (EC-5000) and the Hansatome microkeratome with a 905-mm ring and 180-mm plate. Hyperopic correction was done using a 5.5 to 7.5-mm ablation zone. RESULTS Mean p...