Related Experiment Videos
Corneal healing following laser refractive keratectomy
G L Goodman1, S L Trokel, W J Stark
1Wilmer Institute, Johns Hopkins Hospital, Baltimore, MD 21205.
Archives of Ophthalmology (Chicago, Ill. : 1960)
|December 1, 1989
Summary
Excimer laser ablation for corneal flattening in rabbits showed that shallow procedures (<50 microns) resulted in clear corneas. Deeper ablations (~100 microns) led to opacification and scarring, indicating depth is critical for refractive surgery outcomes.
Area of Science:
- Ophthalmology
- Corneal Surgery
- Laser Technology
Background:
- Excimer laser ablation is a key technique in refractive surgery for correcting vision.
- Understanding the impact of ablation depth and edge profile on corneal healing is crucial for safe and effective procedures.
Purpose of the Study:
- To investigate the effects of varying excimer laser ablation depths and edge profiles on corneal reepithelialization and stromal remodeling in a rabbit model.
- To determine the relationship between ablation depth and the occurrence of corneal opacification and scarring.
Main Methods:
- A 193-nm excimer laser system was used to perform optical contour ablations in rabbit corneas.
- Ablation depths ranged from shallow (<50 microns) to deeper (~100 microns) to achieve desired dioptric corrections.
- Dichlorotriazinyl aminofluorescein was used to study new collagen synthesis and stromal remodeling.
- Corneal clarity, reepithelialization, and stromal changes were assessed biomicroscopically and histopathologically.
Main Results:
- All ablated corneas successfully reepithelialized without recurrent erosions.
- Corneas with ablation depths less than 50 microns remained clear centrally at 8 weeks post-procedure.
- Deeper ablations (~100 microns) resulted in significant opacification and scarring in two specimens.
- Clear corneas showed no evidence of new collagen formation or epithelial hyperplasia, while scarred corneas exhibited stromal remodeling.
Conclusions:
- Excimer laser ablation depth significantly influences corneal healing outcomes.
- Shallow ablations are associated with clear corneas and successful visual rehabilitation.
- Deeper ablations carry a higher risk of corneal opacification and scarring, necessitating careful control of laser parameters in refractive surgery.