Oval host wounds and postkeratoplasty astigmatism

Area of Science:

• Ophthalmology
• Corneal Surgery
• Biomedical Engineering

Background:

• Penetrating keratoplasty (PKP) is a common corneal transplant procedure.
• Postoperative astigmatism is a frequent complication following PKP, impacting visual outcomes.
• The geometric relationship between the recipient corneal bed and donor graft is crucial for refractive stability.

Purpose of the Study:

• To investigate the association between recipient corneal bed ovality and the degree of postoperative astigmatism after penetrating keratoplasty.
• To quantify the impact of recipient bed shape deviation on refractive outcomes in a rabbit model.

Main Methods:

• A rabbit model was utilized to simulate penetrating keratoplasty.
• Animals were categorized based on the ovality of the recipient corneal bed, measured against a 7.25-mm diameter circle.
• A standardized 7.75-mm round donor corneal button was used for all transplants.
• Postoperative astigmatism was assessed using keratometry at 3 months post-suture removal.

Main Results:

• A positive correlation was observed between increasing recipient bed ovality and the magnitude of postoperative astigmatism.
• Greater deviation from a circular recipient bed resulted in higher levels of induced astigmatism.
• The effect was evident 3 months after suture removal, indicating a sustained impact.

Conclusions:

• Recipient corneal bed ovality is a significant factor contributing to postoperative astigmatism following penetrating keratoplasty.
• Optimizing recipient bed shape during PKP may help minimize induced astigmatism and improve visual acuity.
• This rabbit model provides valuable insights into the biomechanical factors influencing refractive outcomes in corneal transplantation.