Exogenous All-Trans Retinoic Acid Induces Similar Longitudinal Changes in Ocular Biometry to Hyperopic Defocus in...

This study aims to investigate the longitudinal changes in ocular biometry in mice treated with exogenous all-trans retinoic acid (atRA) and make comparisons with the lens-induced myopia (LIM) model.

Male C57BL/6J mice were administered 10 µl of atRA (1 milligram [mg]/milliliter [mL]) every other two days via peribulbar injection. The LIM group received monocular -30D lenses. Ocular biometrics were measured on Days 0, 3, 6, 10, and 15 using swept-source optical coherence tomography. Scleral thickness (ST) and retinal arc length (RAL) were measured on histological sections.

Both exogenous atRA and negative lenses induced longer axial length (AL) from Day 3 and thinner retinal thickness (RT) from Day 6 (all p < 0.05). An increase in vitreous chamber depth (VCD) was noted from Day 3 in atRA-Treated (p = 0.001) eyes and from Day 6 in LIM-Treated eyes (p < 0.001). The interocular difference in lens thickness (LT) varied significantly over time (p = 0.004) in the atRA group. The LT to AL ratios (LT/AL) for atRA-Treated eyes were notably higher than those for the LIM eyes on Days 10 and 15 (all p < 0.05). The VCD to AL ratios (VCD/AL) were comparable between the two groups, with notable declines observed in the late stage (all p < 0.01). Additionally, both treatment groups showed similarly reduced ST and larger RAL than untreated eyes.

Mice treated with exogenous atRA demonstrated comparable longitudinal ocular biometric alterations to the LIM model, except for the relatively thicker lenses.