Longitudinal changes in intraocular pressure and iris vessels in rats with bulb external scleral explants / 眼科新进展

ABSTRACT

Objective To observe longitudinal changes in the intraocular pressure (IOP),the cornea and iris blood vessels in normal rats with bulb external scleral explants.Methods Totally 18 normal rats were enrolled in the experiment.Conjunctival incisions of the right eyes of these rats were performed,followed by the placement of a balloon catheter under the lateral rectus muscle and inflation at 4-5 ATM.The IOP was measured and iris images were taken longitudinally before and after pressuring and pressure withdrawing respectively.Results IOP was elevated to (40.66 ± 10.55) mm-Hg (1 kPa =7.5 mmHg) immediately after pressing,which was over the baseline (8.45 ± 1.23)mmHg (P=0.000),and then decreased gradually at 15 min,30 min,45min,60 min after pressing,but the IOPs were still greater than the baseline.There were significant differences in IOPs at 15 min,30 min,45 min after pressing and the baseline (all P ＜ 0.05),while no difference in this variable at 60 min after pressing and the baseline (P =0.929).However,the IOP was quickly reduced to (6.09 ± 0.49) mmHg at once after pressure withdrawing,which was below the baseline (P =0.000),and then gradually returned to the baseline at 15 min,30 min after pressure withdrawing.The corneal edema and dilation of iris vessels were observed after pressuring,and following corneal winkle and dilated iris vessels after pressure withdrawing.Conclusion Bulb external scleral explant can result in elevated IOP immediately,then decreased gradually.With the increase of compressing,the IOP of the contralateral eye tends to increase.Bulb external scleral explant may affect uveoscleral outflow pathway of aqueous humor in rats.