Purpose: To evaluate the immediate and long-term effectiveness of a dye-plus-laser irradiation treatment (photochemical keratodesmos [PKD]) for sealing corneal incisions.
Methods: Incisions (3.5 mm) in rabbit corneas were treated on the incision walls with rose bengal dye followed by exposure to 514-nm laser radiation. PKD was evaluated in three groups (n = 3-6) using laser fluences of 115, 153, or 192 J/cm(2) (180-, 240-, and 300- second exposures, respectively) compared with an untreated group (n = 8). The intraocular pressure at which leakage occurred (IOP(L)) during infusion of saline into the anterior chamber was determined. In a long-term study, treated and control corneas were observed weekly for 10 weeks for the appearance of neovascularization, anterior chamber inflammation, iridocorneal adhesion, corneal melting, and scarring.
Results: Immediately after treatment, the IOP(L) increased with increasing laser fluence, producing IOPs of 230 +/- 90, 370 +/- 120, and more than 500 mm Hg at 115, 153, and 192 J/cm(2), respectively, compared with 40 +/- 20 mm Hg in control eyes (P < 0.005). No reduction in the IOP(L) was observed up to 14 days after surgery. Corneal melting in PKD-treated or control eyes was not observed in the 10-week healing study. Neovascularization, which peaked at 4 weeks but resolved by 8 weeks, was detected around the incision in both PKD-treated and control eyes.
Conclusions: Immediate and lasting sealing of corneal incisions was obtained in eyes treated with PKD, using short irradiation times. These results suggest that PKD has potential for improved corneal tissue bonding.