Abstract
Purpose: :
To evaluate the efficacy of topical administration of SLPI (Secretory Leucocyte Protease Inhibitor) and FP-MC (Fusion Protein Cementoin-SLPI ) in rats with alkali injured corneas after 7 days. Results at day 3 had shown that FP-MC had antiangiogenic and antiinflammatory properties.
Methods: :
An alkali injury was performed on the right cornea of 18 rats under general anesthesia, using a 3 mm diameter filter paper containing 1 mol/L sodium hydroxide during 40 seconds. Animals were divided into three groups (n=6 each) and received SLPI (20 µg), FP-MC (2 µg) or vehicle. Treatment was topically administered four times a day for up to 7 days. Thereafter, animals were sacrificed and eyes were extracted and processed using H & E. Histological examination was masked and separately performed by two investigators. The variables studied in a 40x field in the center plus a 40x field in the periphery of the corneas were 1) number of PMN cells, 2) total number of cells in stroma. Extension and depth of neovessels was also analysed in these fields. Results were compared between groups using T-test.
Results: :
The mean of PMN cells was 3.3 in FP-MC treated group, 69.5 in SLPI, 340.3 in Buffer and 0.4 in normal corneas (PF-MC p<0,001 compared to Buffer and SLPI groups). The total number of cells in stroma showed a mean of 101 in FP-MC treated animals, 256 in SLPI, 574 in Buffer and 85 in normal corneas, respectively. The difference between PF-MC rats and other groups was statistically significant (p<0.05).Topographycally, from periphery to the center, FP-MC rats only disclosed neovessels in the first 40X field in 18.7% of cases while in SLPI and buffer groups neovessels reached out the forth and sixth fields in 4.1% and 14.6% of cases, respectively. There was a direct relationship between severity of inflammation and depth of neovascularization. FP-MC showed neovessels only in the superficial third of the corneas in 18.7% of cases, SLPI in 77%, and Buffer in 100% of cases. In SLPI and buffer groups neovessels reached the deepest third of the cornea in 12.5% and 37.5%, respectively.
Conclusions: :
FP-MC, a novel protein, showed antiinflammatory and antiangiogenic properties at 7 days of treatment. Further research will be carried out to determine the usefulness of this agent in ophthalmology.
Keywords: cornea: basic science • neovascularization • inflammation