Laser in situ keratomileusis for different degrees of myopia

Authors


Yi-Yu Tsai
Department of Ophthalmology
China Medical University Hospital
No. 2, Yuh-Der Road
Taichung 404
Taiwan
Tel: + 886 4 2205 2121 (ext. 1141)
Fax: + 886 4 2205 2121 (ext. 1139)
Email: yiyutsai@seed.net.tw

Abstract.

Purpose: To determine the efficacy, predictability, stability and safety of laser in situ keratomileusis (LASIK) in treating patients with different degrees of myopia.

Methods: We enrolled 386 eyes of 200 consecutive patients who underwent LASIK and divided them into four groups according to their degree of preoperative spherical equivalent (SE). Group 1 eyes ranged between − 1.00 and − 3.99 dioptres (D) (low myopia). Group 2 eyes ranged between − 4.00 and − 5.99 D (moderate myopia). Group 3 eyes ranged between − 6.00 and − 9.99 D (high myopia). Group 4 eyes were over − 9.99 D (extreme myopia). Follow-up was at 1 day, 1 week and 1, 3, 6, 12 and 18 months postoperatively.

Results: Our study included 386 eyes of 200 patients with SE ranging from − 3.00 to − 16.00 D (mean − 7.14 ± 2.87 D). All eyes were seen at 1 day postoperatively. A total of 360 eyes (93%) were examined at 1 week, 330 eyes (85%) at 1 month, 281 eyes (73%) at 3 months, 247 eyes (64%) at 6 months, 199 eyes (52%) at 12 months and 142 eyes (37%) at 18 months. The postoperative data from 1 day to 12 months were used because of the low follow-up rate at 18 months postoperatively. Group 1 consisted of 30 eyes. The mean SE was − 3.52 ± 0.43 D preoperatively and − 0.40 ± 0.58 D at 1 month, − 0.46 ± 0.60 D at 6 months and − 0.42 ± 0.50 D at 12 months postoperatively. Uncorrected visual acuity (UCVA) was 20/40 or better in 95% of eyes at 1 day and in 100% of eyes at 6 and 12 months postoperatively. Group 2 consisted of 151 eyes. The mean SE was − 5.36 ± 0.67 D preoperatively and − 0.54 ± 0.78 D at 1 month, − 0.56 ± 0.90 D at 6 months and − 0.55 ± 0.82 D at 12 months postoperatively. Uncorrected VA was 20/40 or better in 95% of eyes at 1 day and in 100% of eyes at 6 and 12 months postoperatively. Group 3 consisted of 167 eyes. The mean SE was − 8.15 ± 0.94 D preoperatively and − 0.58 ± 0.90 D at 1 month, − 0.67 ± 1.00 D at 6 months and − 0.64 ± 0.95 D at 12 months postoperatively. Uncorrected VA was 20/40 or better in 90% of eyes at 1 day and in 98% of eyes at 6 and 12 months postoperatively. Group 4 consisted of 38 eyes. The mean SE was − 11.09 ± 1.10 D preoperatively and − 1.25 ± 1.20 D at 1 month, − 1.13 ± 1.30 D at 6 months and − 1.20 ± 1.25 D at 12 months postoperatively. Uncorrected VA was 20/40 or better in 78% of eyes at 1 day, in 94% at 6 months and in 90% at 12 months postoperatively. Intraoperative complications (free cap) occurred in two eyes and postoperative complications were observed in three eyes, making the total complications rate 1.29% (5/386). Seven eyes lost one Snellen line of BCVA, five lost two lines and two lost more than two lines (total: 3.64%, 14/386).

Conclusion: In conclusion, LASIK is effective, predictable and safe for correcting myopia but is more accurate for correcting myopia up to −10.00 D. With more improvement in algorithms and ablation profile, we believe that LASIK can offer better results for higher myopia.

Ancillary