Comparison of the Change of Intraocular Pressure after Operation between LASIK and PRK

ABSTRACT

The authors compared the intraocular pressure(IOP) after excimer laser photorefractive keratectomy(PRK) and laser-assisted in situ keratomileusis(LASIK) and examined the factors that affected the intraocular pressure following the surgery. One hundred twenty-three patients(184 eyes) park of the cornea with microkeratome(SCMD, USA) and STAR laser(VISX, USA)and 55 patients*76 eyues) who underwent PRK with the sam laser were examied retrospectively. The IOP was meaured in the central part of the cornea with non contact tommeter(NCT, Topcon CT-20, Japan) at 7 day, 2, 6, and 12 months after PRK and LSSIK. the patiehts were divided into two groups PRK group and LASIK group. There was no difference bvwtween the proparative IOPs in the two groups(0.11). Each IOP measure 7 days, 2, 6, and 12 months after PRK and LASIK was significantly lower than that measured before operation(P<0.05). The IOP measured 7 days after PRK or LASIK was significantly lower tham that measured 2.6. and 12 months after PRK or LASIK and , respectively (P<0.05). There were no difference among the IOPs measured 2,6, and 12 month after PRK or LASIK, respectively(P<0.05). The postoperative Change of IOP between PRK and LASIK was significant at 2, 6, and 12 months(P<0.05) except 7 days after surgery(p=0.066). The difference between the properative IOP and the IOP at 6 months after the surgery had the low correlation with the changes of the spherical equivalents and keratomertry readings and total ablation depth in both groups. In conclusion, the decrease of IOP after LASIK was severer than that after PRK and so the IOP measurement is ought to be interpreted carefully after LASIK.