Effect of diode laser cyclophotocoagulation on the anterior segment: an Orbscan Study.

Purpose: To evaluate the effect of transscleral contact diode laser cyclophotocoagulation (TCDLC) on corneal topography, central corneal thickness (CCT), and anterior-chamber depth (ACD).

Methods: The Orbscan II system was used to determine the changes in corneal topography, CCT, and ACD before and after TCDLC in 25 eyes of 24 patients.

Results: Mean prelaser astigmatism was 4.51 +/- 1.81, 4.64 +/- 3.47, and 5.40 +/- 3.04 D at central and 3- and 5-mm zones, respectively. Mean postlaser astigmatism was 4.54 +/- 2.59, 4.75 +/- 3.33, and 5.57 +/- 3.12 D at central and 3- and 5-mm zones at 10 days and 3.99 +/- 2.01, 4.05 +/- 2.20, 5.52 +/- 4.60 D at 1 month, respectively, showing no statistically significant difference. Prelaser CCT was 540.72 +/- 103.48 microm. Postlaser CCT was 617.08 +/- 86.35 microm at 10 days and 569.88 +/- 70.36 microm at 1 month. CCT was significantly thicker at 10 days compared with prelaser CCT, whereas CCT at 1 month was not statistically different. ACD showed a nonsignificant decrease after TCDLC from 3.77 +/- 0.81 to 3.38 +/- 0.85 mm at 10 days and 3.58 +/- 0.78 mm at 1 month.

Conclusions: TCDLC does not alter corneal topography or ACD significantly. However, CCT increases during the 10 days after TCDLC and returns to normal at 1 month, which might be related to the inflammation induced by cyclophotocoagulation. Increased CCT may lead to artificially high intraocular pressure measurements within the first 4 weeks after surgery.