Evaluation of anterior chamber inflammation after corneal refractive surgery

To prospectively evaluate inflammatory response by measuring aqueous flare in the anterior chamber after photorefractive keratectomy (PRK), laser in situ keratomileusis (LASIK), and intracorneal ring segments (ICRS) implantation.

Aqueous flare was measured pre- and postoperatively at days 1, 7, and 21 with a laser flare meter (Kowa FM 500). Thirty-one patients (58 eyes) were randomized, only for low myopia, in three groups treated with PRK (myopia <-4.50 D), LASIK (myopia range between -4.00 and -12.00 D), and ICRS (myopia <-4.50 D).

Mean preoperative flare intensities were similar in the three groups (p< or =0.05; mean, 4.6 photons/ms). In the PRK group, flare increased significantly (mean day 2, 9.5 photons/ms), as it did in the LASIK group (mean day 1, 23.8 photons/ms). In the ICRS group, there was no significant difference between pre- and postoperative levels of flare at any time (mean day 1, 4.9 photons/ms). In all three groups, flare intensity returned to baseline at day 7, except in the LASIK group, which remained at a significantly higher level (mean day 7, 7.7 photons/ms) than the preoperative one.

According to this method, the blood-aqueous barrier seems to be altered in laser procedures, particularly in LASIK, probably in correlation with the depth of photoablation. ICRS implantation did not increase the postoperative flare significantly.