RADIAL AND STAGGERED TREATMENT PATTERNS TO CORRECT HYPEROPIA USING NONCONTACT HOLMIUM-YAG LASER THERMAL KERATOPLASTY

Purpose: To compare the effects of two treatment patterns in the corre ction of hyperopia by noncontact holmium:YAG laser thermal keratoplast y (LTK). Setting: Divisione Oculistica, Ospedale S. Gerardo, Monza, It aly. Methods: Using two treatment patterns, we performed noncontact LT K in one session in 16 eyes of 8 patients with isometropic hyperopic r efractive errors; mean preoperative subjective cycloplegic refraction was +4.90 diopters(D) +/- 1.17 (SD). The treatment consisted of 24 spo ts in three concentric rings of eight spots each; ring diameters were 6.0, 7.0, and 8.0 mm, respectively Each spot received seven pulses of laser energy at 30 mJ/pulse. We treated one eye of each patient with a radial pattern (the spots of the three rings aligned on the eight sem imeridians) and the fellow eye with a staggered pattern (the spots of the contiguous rings at 22.5 degrees from each other). Follow-up at 1, 15, 30, 90, 180, and 360 days included subjective cycloplegic refract ion, uncorrected (UCVA) and spectacle-corrected visual acuity (SCVA), computerized videokeratography (CVK), and Scheimpflug camera examinati on. Results: One year postoperatively, the mean subjective cycloplegic refraction was +2.75 +/- 1.6 D in the eyes treated with the radial pa ttern and +3.40 +/- 1.6 D in those treated with the staggered pattern; the men change in subjective cycloplegic refraction was 2.15 and 1.50 D, respectively. Mean UC-VA improved by five lines in the radial grou p and by four lines in the staggered group. Mean SCVA returned to preo perative levels by day 15 in the radial group and at 1 year in the sta ggered group; at 1 year, SCVA improved by one line in the radial group and remained unchanged in the staggered group. NO eye lost one or mor e lines of SCVA. Refractive astigmatism was essentially unchanged in b oth groups. Scheimpflug photography and CVK indicated larger and more uniform corrected zones in the radial group. Conclusions: Radial and s taggered patterns effectively corrected low hyperopia, although both w ere subject to a certain amount of regression. The radial pattern prod uced faster postoperative recovery of SCVA and demonstrated greater re fractive stability.