HYPEROPIA CORRECTION BY NONCONTACT HOLMIUM - YAG LASER THERMAL KERATOPLASTY - 5-PULSE TREATMENTS WITH 1-YEAR FOLLOW-UP

Background: Previous noncontact holmium (He): YAG laser thermal kerato plasty (LTK) studies on correction of low to moderate hyperopia have u sed treatment algorithms based on ten-pulse, variable-pulse-energy tre atment parameters. The purpose of this study was to evaluate the safet y, effectiveness, and stability of new five-pulse, constant pulse-ener gy treatment parameters for noncontact Ho:YAG LTK. Methods: Thirty-nin e hyperopic patient eyes [up to +4.75 diopters (D) refractive error] w ere treated using simultaneous noncontact delivery of Ho:YAG laser ene rgy (Sunrise) with two symmetrical octagonal rings of eight spots per ring and radial spot patterns on centerline diameters of 5 and 6 mm (g roup A), 6 and 7 mm (group B), or 6.5 and 7.5 mm (group C). Each ring of spots received five pulses of laser light at 5 Hz pulse repetition frequency and a fixed pulse energy of 240 mJ. Thirty of the 39 patient eyes (77%) had I-year follow-up exams. Results: At 1 year, the mean S nellen uncorrected distance visual acuity lines gained was 3.7 +/- 0.5 /6.8 +/- 2.7/5.3 +/- 3.3 for groups A, B, and C. The mean changes in s ubjective manifest refraction (spherical equivalent) were 2.08 +/- 1.1 3 D, -1.83 +/- 0.88 D, 1.22 +/- 0.88 D for groups A, B, and C respecti vely. None of the eyes lost two or more lines of spectacle-corrected d istance visual acuity. Then were no clinically significant complicatio ns in any patient. Conclusion: This clinical study indicates that five -pulse noncontact LTK treatments of low hyperopia are safe and effecti ve. The stability has to be confirmed with longer follow-up.