Immunohistochemical study of localization of extracellular matrix after holmium YAG laser irradiation in rat cornea.
OBJECTIVE
To better understand the corneal responses to holmium YAG (Ho:YAG) laser irradiation, we used immunofluorescent microscopy to examine changes in the localization of the extracellular matrix components, which play important roles in the maintenance of corneal morphology and functions.


METHODS
Rats were irradiated with a Ho:YAG laser. On days 1, 3, and 7 after irradiation, the eyes were enucleated and frozen. Cryosections were made with a cryostat and were stained with antibodies against type I collagen, fibronectin, type IV collagen, or laminin for immunohistochemical study.


RESULTS
One day after Ho:YAG laser irradiation, contraction of the stromal collagen fibrils was observed. Keratocytes could not be observed at the irradiated stromal region on day 1 after irradiation. One week later, however, keratocytes returned to the irradiated area. Although the stromal collagen fibrils had contracted, they were stained by an antibody against type I collagen. Dense fluorescence for fibronectin was observed at the margin of the stromal acellular zone. Both laminin and type IV collagen were observed at the basement membrane under the corneal epithelium, regardless of whether or not the corneas had been irradiated.


CONCLUSIONS
These results suggest that Ho:YAG laser irradiation might be useful for the collagen contraction of stroma, without causing serious damage to the corneal epithelium and the basement membrane.
Tanaka
T
T
Department of Ophthalmology, Yamaguchi University School of Medicine, Ube City, Yamaguchi, Japan.
Furutani-Miura
S
S
Nakamura
M
M
Nishida
T
T
D000818:Animals; D015415:Biomarkers; D003094:Collagen / Q000276:immunology / Q000378:metabolism; D003315:Cornea / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D003319:Corneal Stroma / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D003886:Descemet Membrane / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D019573:Epithelium, Corneal / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005353:Fibronectins / Q000276:immunology / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D007797:Laminin / Q000276:immunology / Q000378:metabolism; D007834:Lasers; D008297:Male; D008856:Microscopy, Fluorescence; D051381:Rats; D011921:Rats, Inbred WKY
D015415:Biomarkers; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D007797:Laminin; D003094:Collagen