Modified lamellar keratoplasties for the treatment of deep stromal abscesses in horses.

The study describes a refined surgical procedure for the treatment of deep corneal abscesses in horses carried out while the horses are sedated but standing, avoiding the need for general anesthesia.

Research context and objective

• The underlying objective of the research was to describe an updated version of deep lamellar endothelial keratoplasty (DLEK) and posterior lamellar keratoplasty (PLK) procedures for standing horses under sedation. This is a significant modification considering the potential complications associated with general anesthesia in horses.

Methodology

• Four horses whose owners didn’t agree to surgery under general anesthesia were chosen for this experiment. These horses were the subjects of standing corneal lamellar keratoplasty procedures to address deep corneal stromal abscesses.
• All the horses were positioned in stocks and sedated with detomidine. Local anesthesia and akinesia were achieved through local eyelid and retrobulbar blocks, and each horse’s head was stabilized with the help of soft pads situated on a mobile cart.
• DLEK and PLK were performed on two horses each for the treatment of deep stromal abscesses (DSA). After the first DLEK, a mid-stromal two-step anterior lamellar keratectomy modification was applied to expedite the closure of the anterior chamber following the removal of the abscess.

Results

• The cosmetic and postoperative visual results were similar in each of the four horses and were also comparable to those reported in previous studies.
• The first DLEK case had the highest number of intra-operative complications, including focal iris and lens damage and postoperative anterior chamber collapse; however, these complications were nearly eliminated in the following cases.
• The DLEK cases showed more postoperative corneal fibrosis, consistent with earlier findings.

Conclusion

• The research concludes that for horses with deep stromal or endothelial abscesses where general anesthesia is not desirable or feasible, modified DLEK and PLK corneal procedures can serve as an alternative to enucleation on a standing, sedated horse.