Genetic and Protein Expression Profile of Conjunctival Bleb Hyperfibrosis in Early Failure of Glaucoma Surgery

Abstract

The early failure of glaucoma surgery is mainly caused by an overly fibrosis at the subconjunctival space causing obliteration of the filtration bleb. Because fibrosis has a suspected basis of genetic predisposition, we have undertaken a prospective study to identify upregulated profibrotic genes in a population of glaucoma patients with signs of conjunctival fibrosis and early postoperative surgical failure. Clinical data of re-operated fibrosis patients, hyperfibrosis patients re-operated more than once in a short time, and control patients with no fibrosis were recorded and analyzed at each follow-up visit. Conjunctival-Tenon surgical specimens were obtained intraoperatively to evaluate the local expression of a panel of genes potentially associated with fibrosis. In order to correlate gene expression signature with protein levels, we quantified secreted proteins in primary cultures of fibroblasts from patients. Expression of VEGF-A, IL-8, C-MYC, and CDKN1A was induced in the conjunctiva of hyperfibrosis patients. VEGF-A and IL-8 protein levels were also increased in fibroblast supernatants. We propose that these proteins may act as biomarkers of conjunctival fibrosis in glaucoma patients undergoing filtering surgery. Molecular markers could be crucial for early detection of patients at high risk of failure of filtration surgery leading to more optimal and personalized treatments.