Lower Energy to Make a Corneal Flap with a 60 kHz Femtosecond Laser Reduces Flap Inflammation and Corneal Stromal Cell Death But Weakens Flap Adhesion.
10.3341/kjo.2013.27.2.120
- Author:
Jae Yong KIM
1
;
Sung Woo JOO
;
Jung Hae SUNWOO
;
Eun Soon KIM
;
Myoung Joon KIM
;
Hungwon TCHAH
Author Information
1. Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. hwtchah@amc.seoul.kr
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
Apoptosis;
Femtosecond laser;
Flap inflammation;
Tissue adhesions
- MeSH:
Animals;
Cell Death;
Corneal Stroma/*pathology/*surgery;
Keratitis/*pathology/*prevention & control;
Laser Therapy/*methods;
Male;
Models, Animal;
Rabbits;
*Surgical Flaps;
Tissue Adhesions/pathology/surgery
- From:Korean Journal of Ophthalmology
2013;27(2):120-125
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: To compare corneal flaps created in rabbits with a 60 kHz femtosecond (FS) laser using different levels of raster energy and to measure early inflammation, corneal stromal cell death, and late postoperative adhesion strength. METHODS: Sixty rabbits were divided into three groups of 20 each. A flap 110 micrometer thick and 9.0 mm in diameter was made in one eye of each rabbit at raster energies of 0.7 microJ, 1.1 microJ, and 2.4 microJ. Histopathological evaluation for inflammation and apoptosis using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed at 4 and 24 hours after flap creation. The adhesion strength of the flaps was measured with a tension meter at 1 and 3 months. RESULTS: Twenty four hours after flap creation, the 2.4 microJ group had more inflammatory and CD11b-positive cells than the 0.7 and 1.1 microJ groups. The number of TUNEL-positive cells increased with raster energy at 4 and 24 hours. The grams of force (gf) needed to detach the flaps at 3 months was significantly higher in 2.4 microJ group (170 gf) than in 0.7 microJ group (97.5 gf) and 1.1 microJ group (100 gf, p = 0.03). CONCLUSIONS: Using raster energy lower than 1.1 microJ to make a flap with a 60 kHz FS laser decreases inflammatory cell infiltration and corneal stromal cell death in the central cornea but may result in a weaker flap than using higher raster energy (2.4 microJ).
