Development of a Hyperopia Animal Model Using Blue Light in Guinea Pigs.

Purpose: The majority of existing studies have focused on the progression of myopia, while an animal model for hyperopia has not yet been developed. This study aimed to evaluate whether blue light exposure can suppress emmetropization in a manner comparable to lens-induced hyperopia, thereby facilitating the development of an experimental animal model of hyperopia.

Methods: Five-day-old 24 guinea pigs were randomly assigned to different experimental groups based on light exposure conditions. They were housed under a 12-hour light/dark cycle (lights on at 8 AM and off at 8 PM) and exposed to either white light (control) or blue light (460 ± 20 nm). To induce hyperopia, a custom-designed +10 diopter (D) lens was fabricated using a 3D printer and securely attached to randomly selected one eye with Velcro and tissue adhesive. Refractive errors, corneal curvature, and axial length were measured using streak retinoscopy and A-scan ultrasound, with repeated measurements to assess inter-eye deviation.

Results: At the end of the treatment period (6 weeks), guinea pigs reared under blue light with an attached +10 D lens exhibited a significantly greater hyperopic shift compared to those reared under blue light without the lens. In contrast, guinea pigs raised under white light underwent emmetropization regardless of +10 D lens attachment.

Conclusion: Blue light exposure significantly suppresses emmetropization by inducing a marked hyperopic shift in guinea pigs, whereas white light conditions support normal emmetropization regardless of lens attachment. These findings suggest that blue light plays a crucial role in hyperopia induction and can be effectively utilized to establish a stable hyperopia animal model.