Nitric oxide levels in aqueous humor after lens extraction and poly(methyl methacrylate) and foldable acrylic intraocular lens implantation in rabbit eyes

Abstract

Purpose To measure the nitric oxide (NO) level in the aqueous humor of rabbit eyes after common cataract surgery techniques. Setting Department of Ophthalmology, Military Medical University, and Department of Immunology and Immunotoxicology of Respiratory System, Clinic of Pneumonology and Allergology, Medical University of Łódź, Łódź, Poland. Methods Thirty rabbits were randomly divided into 4 groups, and surgery was performed as follows: Group 1, extracapsular cataract extraction (ECCE) and poly(methyl methacrylate) (PMMA) intraocular lens (IOL) implantation; Group 2, ECCE; Group 3, phacoemulsification and foldable acrylic IOL implantation; Group 4, phacoemulsification. The aqueous humor specimens were collected on days 1, 3, and 5. Nitric oxide measurements were performed indirectly with a spectrophotometer. The NO level in the aqueous humor collected before surgery served as a control group. Results In the physiological condition, the concentration of NO was 26.52 nm/dL ± 4.86 (SD). Postoperatively, the highest NO level in each groups was as follows: Group 1, 46.26 ± 5.23 nm/dL on day 3; Group 2, 72.46 ± 6.94 nm/dL on day 1; Group 3, 41.04 ± 7.31 nm/dL on day 1; and Group 4, 32.67 ± 2.84 nm/dL on day 3. Significantly higher levels of NO (P < .05) were observed in Groups 1 and 2 at each follow-up day; in Group 3, on days 1 and 3; and in Group 4, on day 3. Conclusions Techniques of cataract extraction caused the NO level to increase; however, phacoemulsification with a foldable IOL caused the smallest release of NO. Rapid postoperative NO changes may theoretically contribute to blood−aqueous barrier breakdown secondary to cataract surgery.