Purpose: To determine if genes can be transferred to fibroblasts in the filtering bleb using adenoviral vectors.
Materials and methods: Twelve New Zealand albino rabbits underwent bilateral full-thickness sclerostomies. On postoperative day 1 an adenoviral vector carrying a reporter gene (lacZ) was injected into the right-eye bleb and saline was injected into the left eye bleb of each rabbit. Three rabbits were euthanized on each of the after days (days 3, 7, 14, and 21). The eyes were enucleated and tissue samples from the filtering bleb were processed for beta-galactosidase activity (a marker for lacZ gene expression) and expression of vimentin (a fibroblast marker). The median number of cells per high-power field with both beta-galactosidase activity and vimentin expression on days 3, 7, 14, and 21 in the right and left eyes were counted to determine adenoviral-mediated gene expression in fibroblasts.
Results: In the adenoviral vector-treated eyes, the median number of cells per high-power field with both beta-galactosidase and vimentin expression on days 3, 7, 14, and 21 was 83,100, 1, and 0, respectively. No beta-galactosidase activity was noted in the saline-treated eyes.
Conclusions: Adenoviral vectors can transfer genes to fibroblasts in filtering blebs after glaucoma surgery. The peak efficiency of gene transfer to fibroblasts occurred 7 days after glaucoma surgery. These studies show a potential for genetic manipulation of fibroblast activity in filtering blebs after glaucoma surgery.