PRK, LASIK show equal long-term results
January 5, 2009
LASIK is the most popular laser vision correction surgery worldwide — due largely because it involves little or no discomfort and many patients have excellent visual acuity within 24 to 48 hours after surgery.
PRK is preferred by some eye surgeons and patients because it eliminates the risk of flap complications during and after surgery. PRK is far less popular than LASIK, however, because vision recovery is slower and postoperative discomfort can be significant the first few days after surgery.
But how do the long-term visual outcomes of the two procedures compare?
PRK vs. LASIK over a 4-year period
In a recent Japanese study, researchers compared the visual acuity results of PRK and LASIK over a 4-year period.
PRK was performed on 22 eyes of 22 patients and LASIK was performed on 18 eyes of 18 patients. All patients were examined over a 4-year follow-up period.
The following criteria were evaluated for both groups throughout the 4-year study period:
- Uncorrected visual acuity (UCVA)
- Best spectacle-corrected visual acuity (BSCVA)
- Percentage of eyes within +/-0.50 diopter (D) of the intended target refraction
Results
The data gathered during the course of the study yielded these results:
- The average UCVA was significantly better in the LASIK group at 6 and 12 months after surgery, but there was no difference in the average UCVA between the two groups two years after surgery.
- The average BSCVA was significantly better in the LASIK group at 6, 12 and 24 months after surgery, but there was no difference in the average BSCVA between the LASIK and PRK groups three and four years after surgery.
- The percentage of eyes within ±0.5 D of the targeted refraction was not significantly different between the LASIK and PRK groups at any time.
Conclusions
The researchers concluded that though LASIK has short-term visual acuity advantages over PRK, these advantages were not retained four years after surgery.
They attributed this to a mild regression of myopia and corresponding decline in uncorrected visual acuity over time among the eyes treated with LASIK, while the visual results among the PRK showed no comparable degradation over time.