CORRECTION OF HYPEROPIA WITH NONCONTACT HO-YAG LASER THERMAL KERATOPLASTY

PURPOSE: To assess the potential of non-contact holmium:YAG laser ther mal keratoplasty to safely and effectively correct hyperopia up to +5. 00 diopters(D). METHODS: Non-contact laser thermal keratoplasty with a holmium:YAG laser using energies ranging from 215 to 255 mJ with 6, 7 , and 8-mm ablation zone diameters, was applied to 57 sighted eyes of 42 hyperopic patients in a controlled study. All patients were followe d for 15 months after surgery RESULTS: Preoperative spectacle-correcte d visual acuity returned to baseline levels from 2 to 6 weeks after tr eatment. Regression of effect was evident in all eyes, and after 15 mo nths was total in 18 eyes (31.5%). The mean cycloplegic refraction bef ore surgery was +3.80 +/- 0.22 D (range, +1.50 to +5.00 D); after surg ery, it was +1.40 +/- 0.12 at 3 months, +1.69 +/- 0.19 D at 6 to 8 mon ths, and +1.73 +/- 0.16 D at 15 months. At the end of the study, 41 ey es (71.9%) had an uncorrected visual acuity of 20/40 or better. Thirty -two eyes (58.8%) were within +/- 1.00 D of the intended refraction. P atient age and central pachymetric values were significantly correlate d with regression (ANOVA, p less than .005). CONCLUSION: Regression of initial effect can be large with non-contact holmium:YAG laser therma l keratoplasty. We think the technique works best up to +3.00 D in old er individuals with central corneal thickness less than 525 mu m. Algo rithms to improve the final results should include an initial calculat ed overcorrection adjusted on variables that influence regression such as patient age and corneal thickness.