Effects of topical docosahexaenoic acid on postoperative fibrosis in an animal model of glaucoma filtration surgery

Purpose: The aim of this study was to evaluate docosahexaenoic acid (DHA) as a potential antifibrotic agent after glaucoma filtration surgery (GFS) in rats.

Methods: A total of 36 10-week-old Brown Norway rats underwent GFS. Animals were equally divided into three groups: a control group, a DHA group and a mitomycin C (MMC) group. Intraocular pressure (IOP) was measured using a dynamic rebound tonometer, and a photograph of the surgical site was taken on days 1, 3, 7, 10, 14 and 17. The incorporation of DHA into fibroblasts was evaluated by gas chromatography. The expression of alfa-smooth muscle actin (α-SMA) and Smad proteins was assessed by Western blotting.

Results: IOP decreased after surgery in animals from the three groups on day 1 after surgery. Over time, IOP remained lower in the DHA and MMC groups than in the control group (median [interquartile range] 8.0 [7.0-8.0] and 8.0 [7.3-8.0] mmHg vs. 9.0 [8.0-9.0] mmHg, respectively; p < 0.001). Bleb area in the DHA and MMC groups remained larger than that of the control group from day 7 to day 14 (3.9 [2.9-5.2] and 3.5 [2.3-4.4] mm² vs. 2.3 [2.0-2.8] mm² , respectively; p = 0.0021). We did not observe any change in DHA concentrations in the fibroblasts of the DHA group compared with the other groups.

Conclusion: The impact of DHA on IOP and bleb area was similar to that of MMC. The mechanisms of action of DHA in rat eye fibroblasts deserve further investigation.