J Korean Ophthalmol Soc.  2004 Oct;45(10):1724-1730.

A Comparative Study for Mesopic Contrast Sensitivity between Keratectomy(PRK) and Laser in Situ Keratomileusis(LASIK)

• Jun JB
• Lee JE
• Lee JS

Abstract

PURPOSE
To compare the effect on visual performance of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) with mesopic contrast sensitivity using CSV-1000S in excimer laser refractive surgery using the broad beam type and manual microkeratome. METHODS: Postoperative visual performance for 40 eyes undergoing PRK and 40 eyes undergoing LASIK was compared with mesopic contrast sensitivity at 1, 3, and 6 months postoperatively using the CSV 1000 (VectorVision, Ohio, USA). Eyes were divided into two groups: less than 6.0 D and over 6.25 D. Mesopic contrast sensitivity was performed with the patient's uncorrected-visual acuity of 20/20 or better under photopic condition. RESULTS: Under mesopic conditions a significant decrease in contrast sensitivity for the postoperative PRK and LASIK group was obtained at all spatial frequencies compared to the preoperative baseline (p<0.05). At 6 months postoperatively, LASIK decreased mesopic contrast sensitivity significantly more than PRK in myopia below -6.0 D, especially at the middle and high spatial frequencies of 6, 12, and 18 cpd (p<0.05). However, there were not statistically significant differences in mesopic contrast sensitivity between PRK and LASIK in myopia above -6.25 D (p>0.05). CONCLUSIONS: In the broad beam excimer laser, in cases of myopia with below 6.0 D, PRK seemed to have a more significant effect on mesopic contrast sensitivity than LASIK using manual microkeratome at postoperative 6 months.

Keyword

Contrast sensitivity; LASIK; Mesopic condition; PRK

MeSH Terms

Contrast Sensitivity*
Keratomileusis, Laser In Situ
Lasers, Excimer
Myopia
Ohio
Photorefractive Keratectomy
Refractive Surgical Procedures