Establishing a Porcine Eye Model for Manual Sub-Bowman Layer Photorefractive Keratomileusis

Area of Science:

• Ophthalmology
• Corneal Surgery
• Refractive Surgery

Background:

• Surface ablation refractive surgery aims to correct vision errors.
• Traditional methods like transepithelium photorefractive keratectomy (TransPRK) remove the corneal epithelium and Bowman layer (BL).
• A novel approach, manual sub-Bowman layer photorefractive keratectomy (SBPRK), aims to preserve the BL.

Purpose of the Study:

• To establish a porcine eye model for manual sub-Bowman layer photorefractive keratectomy (SBPRK).
• To compare the outcomes of SBPRK with TransPRK in a porcine model.
• To evaluate the feasibility of preserving the corneal Bowman layer (BL) during refractive surgery.

Main Methods:

• Developed an SBPRK technique using mechanical BL flaps followed by laser ablation in 8 pigs (11 eyes).
• Included a TransPRK group (3 eyes) and a control group (2 eyes).
• Utilized slit-lamp biomicroscopy and optical coherence tomography (OCT) for follow-up over 8 weeks.

Main Results:

• SBPRK showed significantly less corneal haze (Stage 1) compared to TransPRK (Stage 2) at 4 weeks post-surgery.
• OCT revealed high reflection within the BL in the SBPRK group, resolving by 8 weeks.
• TransPRK showed diffused high reflection in the anterior stroma, persisting longer than in the SBPRK group.

Conclusions:

• Preserving the BL during surface refractive surgery may lead to reduced corneal haze compared to TransPRK.
• The SBPRK technique shows promise but requires further refinement for clinical application.
• This porcine model provides a basis for future studies on BL-preserving refractive surgery.