Yonsei Med J.  1998 Aug;39(4):317-321. 10.3349/ymj.1998.39.4.317.

Comparison of corneal centering in photorefractive keratectomy

• Kim EK
• Jang JW
• Lee JB
• Hong SB
• Lee YG
• Kim HB

• KMID: 711564
• DOI: http://doi.org/10.3349/ymj.1998.39.4.317

Abstract

The present study compares three centering methods for excimer laser photorefractive keratectomy (PRK. VISX 20/20) by analyzing the corneal topography. The subjects were grouped according to three different centering methods used in the procedure: an ablation using a light reflex from the patient's cornea pursued by both eyes of the surgeon (Group 1, n = 49); an ablation using a red light reflex from the patient's cornea pursued by the surgeon's left eye only while the right eye remained closed (Group 2, n = 27); an ablation using the patient's center of the pupil pursued by the surgeon's left eye only while the right eye remained closed (Group 3, n = 21). The mean distance from the center of ablation zone to the center of the pupil were; 0.69 +/- 0.45 mm for Group 1, 1.05 +/- 0.48 mm for Group 2 and 0.63 +/- 0.28 mm for Group 3. The degree of deviation in Group 2 was significantly greater than in Group 1 or Group 3. The deviation was greater in the right eyes than the left eyes in Group 2 only. The decentration of the right eye in Group 2 was due to angle Kappa with misalignment of the fixation light and viewing tube containing reticule.

Keyword

Centering method; photorefractive keratectomy; topography

MeSH Terms

Adult
Comparative Study
Female
Human
Keratectomy, Photorefractive, Excimer Laser/methods*
Male