玻璃体切割术后前房氧含量变化研究

目的 观察兔眼玻璃体切割(玻切)术后前房氧含量的变化,探讨玻切术后发生白内障的可能机制.方法 40只兔随机分为A、B,C、D四组,每组10只兔.A组为空白对照组,其前房氧分压和氧含量作为基线值;B组为玻切术中充填平衡盐溶液(BSS)组;C组为玻切术中充填惰性气体(C_3F_8)组;D组为玻切术中充填硅油组.采用血气分析法分别测量A组及B、C、D三组术后1d、3d、7d、1月、3月前房氧分压,根据Henry定律计算氧含量.结果 前房氧分压和氧含量基线值分别为(4.90±0.06)kPa、(1.24±0.01)μl/ml;B、C两组术后各时间段的氧分压和氧含量均高于基线值(P<0.05);D组术后1d、3d、7d、1月的氧分压和氧含量高于基线值(P<0.05),3月时氧分压和氧含量回落至基线值.结论 玻切术后,玻璃体腔填充物不同,前房氧含量的变化不同;前房氧含量的增加,在一定程度上可能促进了术后白内障的形成.

The change of aqueous humor oxygen content after vitrectomy

Objective To observe the change of aqueous humor oxygen content in rabbits after vitrectomy,and to explore the possible mechanism of cataract after vitrectomy.Methods Forty rabbits were divided into four groups.Group A was served as control without surgery.The partial pressure of oxygen(PO_2)and oxygen content of this group were provided as baseline value.Group B was filled with balanced salt solution (BSS)during vitrectomy.Group C with C_3F_8 and Group D with silicone oil.The PO2 was measured with blood-gas analysis at 1d,3d,7d,1m,3m after vitrectomy.And oxygen content in aqueous humor was calculated according to Henry's law.Results The baseline value of PO_2 and oxygen content was(4.90±0.06)kPa and(1.24±0.01)ul/ml.The PO_2 and oxygen content of Group B and Group C at different period times were all higher than the baseline value(P＜0.05).That of Group D was also higher than the baseline value at 1d,3d,7d,1m after vitrectomy(P＜0.05).But at 3m post-operation,The PO_2 and oxygen content were dropped back to the baseline value.Conclusions The increasing of aqueous humor oxygen content is different according to the different intraocular tamponade during vitrectomy.This exposes the crystalline lens to abnormally high oxygen and may lead to cataract formation.