Excessive production of extracellular matrix is a key component in the pathogenesis of Salzmann’s nodular degeneration (SND). In vitro studies of drugs that suppress excessive fibroblast activity may become crucial in developing pathogenetically oriented treatments for SND.

PURPOSE

This study evaluates the antifibrotic properties of pirfenidone and cyclosporine A (CsA) on cell cultures obtained from patients with SND.

MATERIAL AND METHODS

Cell cultures were derived from corneal tissue samples obtained during keratectomy in patients with confirmed SND. Nodular samples were also examined histologically. Fibroblasts were treated with various concentrations of CsA (5, 25, 50 µg/mL) and pirfenidone (100, 500, 1000 µg/mL). Effects were assessed at 24 and 48 hours using metabolic and migration assays, measurement of doubling time, evaluation of proliferation activity, assessment of cell death, and analysis of α-smooth muscle actin (α-SMA) expression.

RESULTS

Histological examination of nodular tissue revealed pathological remodeling of the subepithelial stroma. The phenotypic characteristics of cell cultures derived from biopsies indicated the presence of myofibroblasts. According to the MTT assay, pirfenidone at concentrations of 500 and 1000 µg/mL reduced metabolic activity within 24 hours; similar effects were observed with CsA at concentrations of 25 and 50 µg/mL. Proliferation activity decreased after 24 hours with pirfenidone at 500 and 1000 µg/mL and CsA at 5, 25, and 50 µg/mL. Pirfenidone at 100 and 500 µg/mL did not cause cytotoxic effects. Both drugs reduced α-SMA expression, indicating suppression of excessive myofibroblast activation.

CONCLUSION

Myofibroblast activity markers decreased under the influence of pirfenidone and CsA, suggesting their potential for developing new therapeutic approaches for SND and possibly other diseases associated with pathological corneal fibrosis.