NONCONTACT HOLMIUM-YAG LASER THERMAL KERATOPLASTY TO CORRECT HYPEROPIA - 18-MONTH FOLLOW-UP

Purpose: To assess the safety and efficacy of noncontact holmium:yttri um aluminium garnet laser thermal keratoplasty (Ho:YAG LTK) for correc tion of low to moderate hyperopia. Methods: We performed noncontact Ho :YAG LTK on 1 eye each of 28 patients for correction of hyperopia up t o +3.88 dpt. Treatments were conducted with 1 or 2 symmetrical octagon al rings of 8 spots/ring with centerline diameters of 6 mm (1 ring) or 6 and 7 mm (2 rings), 10 pulses of laser light at 5 Hz pulse repetiti on frequency, variable pulse energy in the range of 208-242 mJ and a n ominal spot diameter between 615 and 623 mu m. Results: At 18 months a fter surgery, 20 of 22 (91%) treated patient eyes had improved uncorre cted distance visual acuity. The mean change in subjective manifest re fraction (spherical equivalent) was -0.52 +/- 0.35 dpt and -1.41 +/- 0 .53 dpt for 1- and 2-ring treatment groups, respectively, with good st ability in the refractive change after 6 months. The mean induced refr active astigmatism was small (0.30 +/- 0.37 dpt/0.25 +/- 0.29 dpt for 1-/2-ring treatments). None of the eyes lost 2 or more lines of specta cle-corrected distance visual acuity. There were no clinically signifi cant changes in glare and contrast sensitivity. Conclusions: Noncontac t LTK treatment of low hyperopia is safe and effective, and it is more stable and less prone to induce astigmatism than previously reported contact mode LTK treatments.