Abstract
Abstract: :
Purpose: To determine the effect of acute and repetitive systemic stress on IOP in glaucomatous and non–glaucomatous mice. Methods: Six month old glaucomatous DBA/2 mice and non–glaucomatous C57BL/6 mice were used. IOP was measured in non–sedated animals that were restrained. Baseline IOP was obtained prior to any stress. Animals were subjected to forced swimming for a period of 15 minutes on day 1 and for a series of four 6 minute periods on day 2. IOP was measured hourly for 2 hours immediately after forced swimming on both days 1 and 2. IOP change from baseline was compared at the various time points in both DBA and C57 animals using analysis of variance. Results: Relative IOP (mean + SD) at baseline as measured by the rebound tonometer was 6.8 (+ 1.8) mmHg (range 4–12mmHg) for the C57BL/6 mice and 7.2 (+ 3.4) mmHg (range 3–15mmHg) for the DBA/2 mice. In C57 animals both acute and repeated systemic stress had no significant effect on IOP (p>0.5 and p>0.4 for absolute and percent IOP change respectively, ANOVA). In contrast, repeated systemic stress caused a significant elevation of IOP in DBA/2 animals (p<0.015 and p<0.005 for absolute and percent IOP change respectively, ANOVA, post–hoc Bonferoni) 2 hours after the series of forced swimming periods on day 2. Conclusions: Repeated systemic stress may have delayed effects on IOP in different mouse strains and maybe a characteristic of glaucoma, such as in the DBA/2 strain.
Keywords: intraocular pressure • stress response