Abstract
Purpose: :
To comparatively evaluate oxidative stress parameters in aqueous humor of dogs experimentally submitted to phacoemulsification with and without intraocular lens (IOL) implantation.
Methods: :
Twelve dogs, mixed breed, with an average weight of 15,8 Kg were submitted to bilateral phacoemulsification, being twelve eyes without IOL implantation (Group 1) and twelve eyes with polymethylacrylate IOL in the capsular bag (Group 2). In the pre–operative and post–opreative periods, the medication consisted of anti–inflammatories, antiobiotics and mydriatics. Aqueous humor (AH) samples were taken by anterior chamber paracentesis, under general anesthesia in the pre–operative period and after 1(T1), 2(T2), 3(T3), 7(T7) and 14(T14) days after surgery. Total antioxidant status was determined as the capacity of aqueous humor to inhibit free radical generation by 2,2–azobis(2–amidopropane) chlorine. Ascorbic acid concentrations was measured by HPLC with UV detection. Protein content was determined with the biuret reagent. Statistical analysis was performed by ANOVA and followed by the paired samples Student t–test when the variables had a normal distribuition and Wilcoxon test when they did not. P[ 0.05 was considered as signifcant.
Results: :
Aqueous humor total protein level increased in both groups, more intensively in Group 2 in all post–opretaive periods: T1(p=0.004), T2 (p=0.002), T3 (p=0.004). T7 (p=0.003) and T14 (p=0.009). Total antioxidant activity in AH decreased in both groups; however, it was more pronounced in Group 2, with statistical significant difference in T1 (p=0.013), T2 (p= 0.016), T3 (p=0.002) and T14 (p=0.033), with no difference at T7. Ascorbic acid concentration in AH presented a remarkably decrease in the first post–operative day, recovering progressively in the two groups. Group 2 showed lower results with statistically significant differences in T1(p=0.003), T3 (p=0.015), T7 (p=0.004) and t14 (p=0.007) except in T2 (p=0.051) when no difference was observed.
Conclusions: :
These results indicate that IOL implantation enhances the oxidative stress condition that follows phacoemulsification lens extraction
Keywords: antioxidants • cataract • crystalline lens