Related Experiment Video
Updated: Jun 27, 2026
Ex Vivo and In Vivo Animal Models for Mechanical and Chemical Injuries of Corneal Epithelium
Published on: April 6, 2022
Haze development after photorefractive keratectomy: mechanical vs ethanol epithelial removal in rabbits
Fabricio Witzel de Medeiros1, Rajiv R Mohan, Chikako Suto
1Cole Eye Institute, The Cleveland Clinic, Cleveland, Ohio 44195, USA.
Purpose:
To compare mechanical and ethanol epithelial removal with respect to myofibroblast development and haze formation after photorefractive keratectomy (PRK).
Methods:
Seventeen rabbits underwent mechanical or ethanol debridement, and the opposite eye of each rabbit served as an unwounded control. In both groups, the epithelium was removed with a spatula and discarded. A -9.00-diopter PRK was performed in each eye. The level of haze in each cornea at 4 weeks was graded at the slit-lamp microscope according to the Fantes scale. Myofibroblast generation was detected with immunocytochemistry for alpha-smooth muscle actin (alpha-SMA) and cells were quantitatively analyzed.
Results:
No difference was noted between the two groups in alpha-SMA + myofibroblasts 4 weeks after surgery (43.6+/-2.0/400x field and 45.7+/-4.8/400x field in ethanol and mechanical groups, respectively) (P=.10). A slight difference was noted but did not reach statistical significance with regard to stromal haze between ethanol and mechanical groups (2.0+/-0.5 and 2.3+/-0.4, respectively, P=.063). The ethanol and mechanical groups were statistically different when compared to controls regarding stromal haze and alpha-SMA+ cells (P<.0001for all comparisons).
Conclusions:
No difference was noted in clinical haze or myofibroblast generation between corneas that had PRK with mechanical or ethanol epithelial debridement.
Insights
Mechanical and ethanol epithelial removal show no significant difference in myofibroblast development or haze formation after photorefractive keratectomy (PRK). Both methods were statistically different from controls regarding stromal haze and myofibroblast generation.
Area of Science:
- Ophthalmology
- Corneal Surgery
- Regenerative Medicine
Background:
- Photorefractive keratectomy (PRK) is a common refractive surgery.
- Epithelial removal is a critical step in PRK.
- Different methods of epithelial removal may impact corneal healing and outcomes.
Purpose of the Study:
- To compare mechanical epithelial removal versus ethanol-induced epithelial removal.
- To assess the impact of these methods on myofibroblast generation.
- To evaluate the effect on corneal haze formation following PRK.
Main Methods:
- Seventeen rabbits underwent PRK after mechanical or ethanol epithelial debridement.
- The contralateral eye served as an unwounded control.
- Corneal haze was graded using the Fantes scale, and myofibroblast generation was quantified using alpha-smooth muscle actin (alpha-SMA) immunocytochemistry.
Main Results:
- No statistically significant difference in alpha-SMA positive myofibroblasts was observed between the ethanol and mechanical debridement groups at 4 weeks (P=.10).
- A trend towards a slight difference in stromal haze was noted between the groups, but it did not reach statistical significance (P=.063).
- Both mechanical and ethanol debridement groups showed statistically significant differences compared to control eyes in terms of stromal haze and alpha-SMA+ cells (P<.0001).
Conclusions:
- Mechanical and ethanol epithelial debridement result in comparable levels of clinical haze and myofibroblast generation after PRK.
- Neither method demonstrated superiority over the other in terms of these specific outcomes.
- Both debridement methods significantly impacted corneal healing compared to untouched controls.
