A transpupillary approach for crosslinking Guinea pig sclera using WST11 and near-infrared light

TL;DR

This study explores using WST11 and near-infrared light to strengthen the sclera in guinea pigs, finding effective crosslinking parameters that work better in older animals.

Contribution

The novel contribution is the transpupillary crosslinking method using WST11 and NIR light in guinea pigs, demonstrating age-related efficacy differences.

Findings

Ex vivo treatment with WST-D and NIR light significantly increased scleral thermal stability compared to controls.

In vivo treatment showed significant crosslinking in both equatorial and posterior scleral regions.

Crosslinking efficacy was greater in older guinea pigs compared to younger ones.

Abstract

Crosslinking strengthens the sclera and holds potential as a treatment for myopia. This study aims to identify optimal crosslinking parameters in guinea pigs using WST11 with dextran followed by near-infrared (NIR) illumination. Guinea pig eyes were incubated in WST11 with 2, 5 or 10% dextran, and penetration depth was assessed by fluorescence microscopy. Crosslinking efficacy was measured as thermal stability using a thermal degradation assay, following incubation in WST11 + 10% dextran (WST-D) for 30 min and NIR irradiation at 10 mW/cm2 or 20 mW/cm2 for 10, 20 and 30 min. The optimized parameters were then applied in vivo in 6-month-old guinea pigs. Ex vivo treatment using the optimal crosslinking parameters (WST-D, 30 min; NIR, 10 mW/cm2, 30 min) resulted in the highest thermal degradation midpoint (ΔT50: 6.8), significantly higher than untreated controls (p = 0.0006), with WST-D penetration limited to the sclera. Efficacy was greater in eyes obtained from older compared to younger guinea pigs (p = 0.02). In vivo, WST-D/NIR treatment resulted in significant crosslinking compared to untreated controls (equatorial, ΔT50: 3.7, p < 0.0001; posterior, ΔT50: 3.4, p = 0.01). WST-D/NIR treatment effectively induces scleral crosslinking, with age-related differences suggesting the need for personalized treatment.

The online version contains supplementary material available at 10.1038/s41598-026-36438-w.

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