Holmium laser thermal keratoplasty for hyperopia and astigmatism after photorefractive keratectomy

PURPOSE: To report results of holmium laser thermal keratoplasty used to tr eat induced hyperopia and induced, as well as pre-existing astigmatism afte r photorefractive keratectomy. METHODS: Sixteen eyes of 16 patients were included in this study. Contact h olmium laser (Technomed Holmium 25) was used in 7 patients to correct hyper opia (8 spots at 8 or 9 mm) and in 9 patients to correct astigmatism (4 spo ts at 7, 8, or 9 mm). Follow-up evaluation was done after at least 6 months . The effectiveness, stability, and safety of the procedure were investigat ed. RESULTS: Spherical correction was ineffective (1.00 D or less) when applied at the 9-mm diameter treatment zone. Spherical correction applied at the 8 -mm diameter treatment zone was ineffective in 1 eye. Three eyes achieved 1 .00 to 2.00 D change, but 2 of these eyes showed an induced astigmatic chan ge as well. Correction of astigmatism at the 7-mm diameter treatment zone r esulted in a 0 to 4.00 D cylinder component change. Treatment at the 8-mm d iameter treatment zone showed a 0 to 1.50 D effect and at the 9-mm treatmen t zone, 0.25 to 1.50 D. All eyes that achieved significant improvement (1.0 0 D or more change in cylinder component) showed significant overcorrection in the first postoperative phase. There were no sight threatening complica tions. CONCLUSION: Holmium laser thermal keratoplasty can be useful for the treatm ent of overcorrection and induced as well as pre-existing astigmatism after photorefractive keratectomy. However, predictability is Low and astigmatis m can be induced with the attempted spherical correction.