SUMMARYA prospective study of excimer laser photo refractive ker atectomy was performed with the aim of correcting a range of myopic errors between -1.00 and -10.00 dioptres . Corneal healing was monitored through the first post-operative year by serial assessments of refrac tion, contrast sensitivity, corneal haze, pachymetry and keratometry. Eighty-one patients were recruited for the study. At 12 months 81 % were within ± 1.00 dioptre of desired emmetropia and with unaided vision of 6/12.Contrast sensitivity was found by Pelli-Robson assess ment to be reduced throughout the 12 months and regres sion analysis predicted recovery by 2 years. At 12 months, however, only 15 % of patients �ere found to have lost a single line of best corrected Snellen acuity. Predictability of results was found to be greatest for initial errors less than -4.00 dioptres. No serious complications were observed during the follow-up period, but refraction had not stabilised in all cases and patients remain under review.

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Aimsibackground-This study evaluated contact lens fitting and the longer term response of the photorefractive keratectomy (PRK) cornea to lens wear.

Silicone rubber contact lenses (SRCLs) are infrequently used because of the risk of developing unpredictable lens tightening, their poor availability, and their expense. However, their high oxygen transmissibility and nonabsorption of water make them valuable as therapeutic lenses. SRCLs are routinely used in our management of severely dry eyes, decompensated or vascularised corneas, and conditions where the corneal shape is flat or irregular. The records of 48 consecutive patients fitted with SRCLs between January 1989 and June 1990 were studied. The clinical history, indications, complications, success, and duration of SRCL wear were analysed. Therapeutic goals, which included epithelial healing, sealing of corneal perforations, and improved comfort and vision, were achieved in 53 of 62 eyes. The best corrected acuity was attained using SRCLs in 58 of 62 eyes. Failure of lens wear was due to lens tightening (four eyes), spoilation (two), discomfort, fornix shortening, handling problems, and decentration (one each). Infective keratitis complicated one case, but SRCL wear was resumed after successful treatment. With adequate follow-up, SRCLs have a low complication rate and are well tolerated even in severely compromised eyes, for which conventional lenses may be contraindicated. Their continued use as therapeutic lenses is advocated in carefully selected cases.

Since the number of patients undergoing radial keratotomy has increased, more have required contact lens fitting to correct residual ametropia. A number of practitioners suggest that the postoperative changes stabilize after 12 months, so contact lens fitting on the unusual resultant corneal topography can begin. This paper discusses corneal and refractive changes that are revealed even when correctly fitting lenses are worn 1-5 years postoperatively. These changes indicate that lens wear may influence corneal topography and refraction even several years after radial keratotomy.