Corneal stromal demarcation line after accelerated crosslinking using continuous and pulsed light

Area of Science:

• Ophthalmology
• Corneal Surgery
• Biomedical Engineering

Background:

• Keratoconus is a progressive eye condition affecting corneal shape.
• Collagen crosslinking (CXL) is a treatment to strengthen the cornea.
• Accelerated CXL techniques aim to reduce treatment time.

Purpose of the Study:

• To compare the depth of the corneal stromal demarcation line after accelerated CXL.
• To evaluate differences between continuous and pulsed ultraviolet-A (UVA) light exposure.

Main Methods:

• A retrospective case series of 60 patients with progressive keratoconus.
• Two groups received accelerated CXL: Group A (continuous UVA) and Group B (pulsed UVA).
• Corneal stromal demarcation line depth was measured using anterior segment optical coherence tomography (AS-OCT) one month post-surgery.

Main Results:

• The mean demarcation line depth was 149.32 ± 36.03 μm for continuous UVA (Group A).
• The mean demarcation line depth was 213 ± 47.38 μm for pulsed UVA (Group B).
• A statistically significant difference (P < .001) in demarcation line depth was observed between the groups.

Conclusions:

• Pulsed UVA light resulted in a significantly deeper corneal stromal demarcation line than continuous UVA light during accelerated CXL.
• This suggests pulsed light may enhance CXL penetration or effect.