Model of naturally occurring refractive error (NORE) in mice

Area of Science:

• Ophthalmology
• Genetics
• Animal Models

Background:

• Traditional animal models for myopia, such as form deprivation (FD) and lens-induced myopia (LIM), have limitations in applicability to human childhood myopia.
• These models often require artificial induction of refractive shifts, potentially not fully recapitulating natural myopia development.

Purpose of the Study:

• To introduce a novel, genetically diverse mouse model of naturally occurring refractive error (NORE).
• To characterize distinct refractive phenotypes within this model, including hyperopic, myopic, and intermediate refractions.
• To establish a valuable tool for investigating the genetic and environmental factors contributing to refractive errors.

Main Methods:

• Cross-breeding of C57BL/6J and 129S2/SvPasCrl mice to generate F1 and F2 offspring.
• Assessment of refractive errors using photorefractometry in F1 and F2 mice at postnatal days 28 and 42.
• Evaluation of ocular parameters including corneal radius, axial dimensions, and retinal function in a subset of mice.

Main Results:

• F2 mice were classified into hyperopic, myopic, and intermediate refractive error groups based on age-dependent trajectories.
• Slower growth in axial length and vitreous chamber depth was observed in intermediate compared to myopic mice.
• Refractive differences were not linked to variations in retinal function or dopamine signaling.

Conclusions:

• The NORE mouse model provides a genetically diverse, wild-type alternative to intervention-based myopia models.
• This model does not require artificial induction methods like FD or LIM.
• NORE mice are a valuable resource for future research on refractive error mechanisms and therapeutic strategies.