Wound anatomy after type 1 Boston KPro using oversized back plates

Area of Science:

• Ophthalmology
• Biomaterials Science
• Surgical Innovation

Background:

• Boston Keratoprosthesis (KPro) is crucial for vision restoration in severe corneal diseases.
• Graft-host junction integrity and anterior chamber angle health are critical for KPro success.
• Optimizing KPro back plate size may enhance surgical outcomes and reduce complications.

Purpose of the Study:

• To compare graft-host junction anatomy and anterior chamber angle after KPro implantation using oversized (9.5-mm) versus standard (8.5-mm) back plates.
• To evaluate the impact of back plate size on wound healing and retroprosthetic membrane (RPM) formation.

Main Methods:

• Anterior segment optical coherence tomography (AS-OCT) was used to image 16 patients (6 with 9.5-mm, 10 with 8.5-mm back plates) 6-12 months post-KPro.
• Assessment included graft-host junction location, corneal thickness, and anterior chamber angle.
• Clinical outcomes and RPM incidence were retrospectively reviewed.

Main Results:

• Oversized back plates ensured complete graft-host junction coverage and better apposition, reducing junctional wound thickness.
• Standard back plates did not fully cover the graft-host junction, leading to significantly thicker junctions.
• No significant RPM developed in the oversized group; one patient with a larger back plate experienced corneal melt at the KPro stem.

Conclusions:

• Oversized KPro back plates provide superior graft-host junction coverage without negatively impacting angle anatomy or wound healing.
• This approach may reduce RPM formation and prevent angle closure due to iris synechiae.
• Oversized back plates represent a promising strategy for improving KPro surgical outcomes.