Age-related changes in eye morphology and aqueous humor dynamics in DBA/2J mice using contrast-enhanced ocular MRI.

PURPOSE: Here, we are testing the hypothesis that dynamic contrast enhanced MRI (DCE-MRI) is a useful approach for non-invasively evaluating age-related changes in aqueous humor outflow and its contribution to elevated intraocular pressure in the DBA/2J model of pigmentary glaucoma. METHODS: A rodent-specific 7 T MRI was used to assess eye anatomy (anterior chamber (AC) and vitreous body (VB) morphology, eye size, lens size) and aqueous humor dynamics (via intravenous administration of Gd-DTPA and Gd-BOPTA contrast agents) in C57BL/6 and DBA/2J mice at 3 and 9 months of age. RESULTS: Gd-MRI was used to demonstrate an anterior solute pathway into the mouse AC. Topical latanoprost treatment in C57BL/6J mice reduced Gd-BOPTA accumulation in the AC. Age-related increases in AC area, AC depth and eye size were observed in DBA/2J mice compared to C57BL/6J mice. The rate of Gd-DTPA accumulation and peak Gd-DTPA intensity was lowest in 9-month old DBA/2J mice compared to 3-month old DBA/2J mice and C57BL/6J mice at both ages. Leakage of Gd-DTPA posteriorly into the VB was also observed in 9-month old DBA/2J mice. CONCLUSIONS: These studies support the idea that age-related changes in aqueous humor outflow contribute to elevated intraocular pressure (IOP) in the DBA/2J model of pigmentary glaucoma. Gd-MRI is a valuable tool for better understanding of mechanisms and dynamics of aqueous humor circulation in normal and glaucomatous mouse eyes or following topical administration of medicines to reduce IOP.

Duke Scholars

Author W Daniel Stamer Ophthalmology, Glaucoma