Emmetropia

Emmetropia And Eye Issues

Two-year data showed that both procedures were successful in achieving emmetropia in the vast majority of eyes. At this time, 85% of PRK eyes and 92% of LASIK eyes were within +1 D of emmetropia. However, visual recovery was faster in the LASIK eyes compared with those treated with PRK, and uncorrected vision levels were superior in the LASIK group.

At 3 months after surgery, 70% of LASIK eyes and 30% of PRK eyes had 20/20 or better uncorrected acuity. At the 2-year visit, 20/20 uncorrected vision was recorded for 61% of LASIK eyes but only 33% of PRK eyes. However, all eyes had uncorrected acuities of at least 20/40.

Median time to recovery of the preoperative level of corrected acuity, defined as recovery to within 1 line of baseline vision, was also markedly shorter in the LASIK eyes (6 days) compared with those treated with PRK (20 days). By 1 year, 93% of the eyes in both groups had either improved or remained within 1 line of preoperative best corrected vision, and at 2 years, none of the eyes showed any loss of best corrected vision. BAT testing at 1 year showed that 72% of LASIK and 76% of PRK eyes had 20/20 or better vision under glare.

Complication rates were relatively low for both procedures. Postoperative haze peaked at 3 months in the PRK eyes and by 1 year the mean haze rating was at a half trace level. At that time, 83% of eyes showed no haze or only trace levels. In the LASIK eyes, only one of 29 eyes examined at 2 years had trace interface haze. Other reported complications included flap displacement with debris or epithelium in the bed in two LASIK eyes and an epithelial defect in one PRK eye.

The results from patient satisfaction surveys indicated that PRK treatment was associated with mild to severe pain in all eyes at 1 day postsurgery, while 82% of LASIK eyes had no pain at this time. Surveys conducted at 2 years showed that complaints of glare, halos, or flare were slightly higher in the PRK eyes, 36%, than in the LASIK group, 26%, while approximately 80% of patients reported having no vision fluctuation during the day with either eye.

Overall satisfaction rates with uncorrected vision were markedly higher for LASIK after 1 year. However, the gap between the two procedures was closed after 2 years as the proportion of patients satisfied with their vision fell in the LASIK group and rose for PRK, and at this time both procedures were associated with high satisfaction rates.