Abstract
Purpose: :
To evaluate a new objective method of semiautomatic processing of the corneal neovascularization
Methods: :
Chemical cauterization of cornea was performed in 40 eyes of 20 rats by using silver nitrate/potassium nitrate sticks. Cauterization was followed by a single subconjunctival injection of bevacizumab (avastin®) in 10 rats (group 1) and by a single subconjunctival injection of dexamethasone in 10 rats (group 2). Percent areas of cornea covered by neovascularization and covered by scar in each group were calculated by use of computer software on digital photographs with a semiautomatic program developed in MATLAB 7 (MathWorks, Natick,MA) to compute the area with neovascularization. A region of interest (ROI) on the cornea was outlined, with the outermost vessel of the limbal arcade used as the border. The algorithm included selection of a threshold level by which it was possible to extract and calculate of the number of pixels corresponding to vessels from the color image. The total area of neovascularization was normalized to the corneal area defined in the ROI, and the percentage of the cornea covered by new vessels was calculated. Groups were compared for any significant differences among them.
Results: :
Neovascularization in bevacizumab (avastin®) group was higher from dexamethasone group (p< 0.05). There were no significant differences in percent area of corneal scar among groups. Further studies are needed to evaluate our objective method of corneal neovascularization in other experimental conditions.
Conclusions: :
We described a new objective method of semiautomatic processing of the corneal neovascularization which was efficient in the determination of corneal neovascularization after chemical burn.
Keywords: cornea: clinical science • clinical research methodology • neovascularization