BACKGROUND: The correction of hyperopia by excimer laser remains challenging because the procedure is followed by regression and loss of effect. We evaluated excimer laser in situ keratomileusis (LASIK) to correct hyperopia and hyperopic astigmatism using the NIDEK scanning slit excimer laser and a modified nomogram. METHODS: The study included the first consecutive 58 eyes treated for hyperopia and hyperopic astigmatism by one surgeon. All eyes were operated at the Alexandria Eye Center, Alexandria, Egypt using the Nidek excimer laser and the Chiron automated corneal shaper. Astigmatic correction was done first by myopic ablation using a 5.0 mm ablation zone and a 5.5 mm transition zone, followed by narrow hyperopic ablation using a 5.5 to 7.5 mm zone. RESULTS: Mean preoperative cycloplegic spherical equivalent refraction was +3.75 D (range, +1.00 to +6.00 D). Mean preoperative astigmatism was 2.75 D (range 0 to 4.00 D). After hyperopic LASIK, all eyes had a reduction in their hyperopia, but regression occurred gradually until the last follow-up examination. At 6 months follow-up, the mean cycloplegic refraction was +2.25 D (range, 0 to +3.25 D). The postoperative astigmatism had a mean of 1.25 D (range 0 to 2.75 D). Four eyes had a reduction in the quality of vision due to a decentered ablation and a small ablation zone, but no other vision threatening complications were reported. CONCLUSION: LASIK to correct hyperopia and hyperopic astigmatism is safe, effective, and repeatable. Predictability and long-term stability needs improvement. A better ablation profile and modified algorithm need to be provided by excimer laser manufacturers.
BACKGROUND: The correction of hyperopia by excimer laser remains challenging because the procedure is followed by regression and loss of effect. We evaluated excimer laser in situ keratomileusis (LASIK) to correct hyperopia and hyperopic astigmatism using the NIDEK scanning slit excimer laser and a modified nomogram. METHODS: The study included the first consecutive 58 eyes treated for hyperopia and hyperopic astigmatism by one surgeon. All eyes were operated at the Alexandria Eye Center, Alexandria, Egypt using the Nidek excimer laser and the Chiron automated corneal shaper. Astigmatic correction was done first by myopic ablation using a 5.0 mm ablation zone and a 5.5 mm transition zone, followed by narrow hyperopic ablation using a 5.5 to 7.5 mm zone. RESULTS: Mean preoperative cycloplegic spherical equivalent refraction was +3.75 D (range, +1.00 to +6.00 D). Mean preoperative astigmatism was 2.75 D (range 0 to 4.00 D). After hyperopic LASIK, all eyes had a reduction in their hyperopia, but regression occurred gradually until the last follow-up examination. At 6 months follow-up, the mean cycloplegic refraction was +2.25 D (range, 0 to +3.25 D). The postoperative astigmatism had a mean of 1.25 D (range 0 to 2.75 D). Four eyes had a reduction in the quality of vision due to a decentered ablation and a small ablation zone, but no other vision threatening complications were reported. CONCLUSION: LASIK to correct hyperopia and hyperopic astigmatism is safe, effective, and repeatable. Predictability and long-term stability needs improvement. A better ablation profile and modified algorithm need to be provided by excimer laser manufacturers.
Authors: R L Lindstrom; D R Hardten; D M Houtman; B Witte; N Preschel; Y R Chu; T W Samuelson; E J Linebarger Journal: Trans Am Ophthalmol Soc Date: 1999