Diode Laser Thermal Keratoplasty to Correct Hyperopia

Abstract

We investigated long-term efficacy, predictability, stability, and safety of diode laser thermal keratoplasty (DTK) to correct hyperopia. DTK was performed on 24 eyes (18 patients). Eight eyes with high hyperopia (mean +4.75 +/- 0.63 D; range +3.50 to +5.50 D) received 12 pairs of coagulation spots at 6-mm and 7-mm treatment zone diameters; eight eyes with low hyperopia (mean +2.25 +/- 0.40 D; range +1.50 to +2.75 D) received eight coagulation spots at 8 mm, and eight eyes with low hyperopia (mean +1.50 +/- 0.46 D; range +1.25 to +2.25 D) were treated to induce mild myopia (-1.50 D) in the non-dominant eye for monovision using eight pairs of spots at 7 and 8-mm diameters. Minimum follow-up was 18 months. Mean decrease in cycloplegic refraction at 18 months was 5.00 +/- 0.38 D in the high hyperopia group, 1.75 +/- 0.19 D in the low hyperopia group, and 3.25 +/- 0.27 D in the presbyopia group. Mean increase in uncorrected visual acuity (UCVA) at 18 months was 8.125 +/- 2.1 Snellen lines in the high hyperopia group, 6.625 +/- 0.744 lines for low hyperopia; decrease of 1.00 +/- 1.85 line occurred in the presbyopia group. Near UCVA in the presbyopia group improved by 3.875 +/- 0.83 Jaeger lines. Best spectacle-corrected visual acuity (BSCVA) was restored by 3 months in all eyes. DTK was an effective and fairly safe procedure, with reasonable predictability and stability. Nomograms for laser energy level, treatment zone diameter, and number of spots need improvement.