COMPARISON OF THE ANTERIOR-CHAMBER INFLAMMATORY RESPONSE TO DIODE ANDARGON-LASER TRABECULOPLASTY USING A LASER FLARE METER

Background: Diode laser trabeculoplasty (DLT) has a similar hypotensiv e action to argon laser trabeculoplasty (ALT). However, anterior chamb er inflammatory response and laser-induced discomfort are less pronoun ced with DLT. The authors compared the breakdown of the blood-aqueous barrier after DLT and ALT over the time course of 1 week and the hypot ensive action over 8 weeks. Methods: Twenty-five patients with uncontr olled intraocular pressure (IOP) were randomized to either DLT or ALT. If two eyes required treatment, then the second eye would be treated with the alternative laser to the first. Flare values were measured at 1, 3, 24, 48, 72, 96, and 168 hours using a laser flare and cell mete r. Intraocular pressures were measured at similar intervals and at 8 w eeks. Results: Of 38 eyes treated, 21 underwent ALT and 17 DLT. Both f orms of treatment induced a similar hypotensive effect with a signific ant reduction in IOP at 8 weeks compared with initial IOP (P < 0.01) ( paired Student's t test). However, there was a significantly greater d isruption of the blood-aqueous barrier with ALT when compared with DLT at 1, 3, and 24 hours (P < 0.001) and at 48, 72, and 96 hours (P < 0. 01) (unpaired Student's t test). By 1 week, however, there was no sign ificant difference in flare values between the two groups. Postlaser p ain occurred in seven eyes treated with ALT but in no eyes treated wit h DLT. In addition, peripheral anterior synechiae occurred in four eye s after ALT by 8 weeks but none occurred in the DLT group. Conclusion: Argon laser trabeculoplasty produces a greater disruption of the bloo d-aqueous barrier than DLT. This may be associated with the developmen t of complications in the anterior segment.