Time-course characterization of intraocular pressure in murine steroid-induced ocular hypertension: Effects of route, schedule, and concentration.

Intraocular pressure (IOP) is the only modifiable risk factor for glaucoma, making animal models of ocular hypertension (OHT) foundational for research. Steroid-induced OHT is a strong candidate model, yet published steroid models rarely provide quantitative guidance on how route, dose, and schedule shape the pressure-time course, leaving laboratories to pilot protocols and hindering cross-study comparisons. We examined an OHT model using depot dexamethasone acetate injections, and systematically characterized IOP profiles in C57BL/6J mice across two injection routes (subconjunctival or periorbital), two dosing schedules (3 doses/1 week; 5 doses/4 weeks), and two concentrations (20 μL, 10 or 20 mg/mL). Steroid exposure produced OHT in every treated mouse, occurring rapidly by day 2, peaking on days 27-31, and declining to baseline by day 98. Maximum IOP increased ~90%-100% above baseline (from ~11-12 mmHg to ~22-23 mmHg). Increasing the dosing regimen from three to five doses modestly raised mean IOP over the study period without changing maximum IOP and peak timing. Increasing dexamethasone concentration increased maximum and mean IOP, without prolonging the duration of IOP elevation. Subconjunctival and periorbital injections were performed similarly, with consistent responses across sexes and minimal diurnal variation. These results provide researchers with clear benchmarks for selecting steroid regimens, guide interpretation of therapeutic effects, and offer a reproducible, practical platform for glaucoma research.