Light microscopic evaluation and scanning electron microscopic analysis of horse eyes following deep anterior lamellar keratectomy.

The article describes a study which evaluated two techniques for deep anterior lamellar keratoplasty (DALK), a type of eye surgery, in horses. The outcomes demonstrated no significant differences in safety or efficacy between the two methods.

Objective and Animals Studied

• The aim of this study was to demonstrate the technique of deep anterior lamellar keratoplasty (DALK), an eye surgery, and examine the efficacy and safety of two techniques—viscodissection and big-bubble.
• This research was conducted on 34 ex vivo horse eyes, meaning they were studied outside of the living body.

Procedure

• The researchers performed the DALK procedure on the horse eyes and created two separate study groups.
• Group V (17 eyes) underwent viscodissection, a technique that uses 2% sodium hyaluronate, and Group A (17 eyes) underwent the big-bubble method, which involves enclosing the eye within an air-filled bubble.
• Each group’s surgical procedure was identical aside from the substances used.
• Any eyes that were not perforated during surgery were submitted for light microscopic histologic evaluation and scanning electron microscopic (SEM) analysis, which are methods of examining the eye’s biological tissues.

Results

• In Group V, surgical perforations were found in 18% of the eyes, and light microscopy revealed Descemet’s membrane (DM) exposure in only 28% of eyes. The average thickness of the remaining stroma, the middle layer of the eye, was about 70.4 micrometers.
• In Group A, perforations occurred in 42% of the eyes, while DM exposure was identified in 60% of eyes. The average remaining stroma thickness was significantly reduced at 23.3 micrometers.
• No considerable differences in safety and efficacy were found between the two groups of eyes.
• The SEM findings showed that the surgical site’s surface was smoother in the eyes that had DM exposure than those with a thicker stroma in both groups.

Conclusions

• The study introduces and describes two DALK techniques—viscodissection and the big-bubble method—for use in horses.
• Both techniques, according to the study’s findings, demonstrated comparable safety and efficacy levels, despite variations in the extent of DM exposure and stroma thickness.
• However, the analyses suggested a non-significant trend toward the big-bubble method being slightly more effective yet somewhat less safe.