Audible pops during cyclodiode procedures

Purpose: This study was conducted to determine the incidence of intraocular uveal microexplosions ("pops") during contact diode laser transscleral cyc lophotocoagulation (cyclodiode) and to analyze the influence of pop occurre nce on results and postoperative complications. Methods: Cyclodiode treatment (1.5-2 W x 2 seconds over 270 degrees) was pe rformed in 43 consecutive patients (43 eyes) with uncontrolled glaucoma who had not undergone previous ciliary ablation. Mean duration of follow-up ev aluation was 12.7 months (range, 9-18 months). These eyes included 31 seein g eyes, in which intraocular pressure (IOP) reduction was indicated to pres erve visual acuity (therapeutic group) and 12 blind eyes, in which IOP redu ction was advisable to relieve pain (palliative group). Success was defined as a final IOP greater than or equal to 5 mmHg and less than or equal to 2 1 mmHg in seeing eyes, and as the resolution of pain in blind eyes. Potenti al factors evaluated for intraoperative pop occurrence included patient age , gender, iris color, glaucoma diagnosis, preoperative IOP, and number of p revious surgical procedures used to treat glaucoma. Results: In the group receiving therapeutic treatment, mean +/- standard de viation (SD) IOP was 41.8 +/- 12.7 mmHg before surgery and 19.2 +/- 8.3 mmH g after surgery; the success rate in this group was 83.9%. In the group rec eiving palliative treatment, mean IOP was 55.4 +/- 13.7 mmHg before surgery and 21.1 +/- 13.4 mmHg after surgery; success rate was 83.3% in this group . Intraoperative microdisruptions occurred in 48.8% of the cases during the first laser application; 67.5% of these occurred in the superior half of t he eye. No significant difference in rate of intraoperative pop was observe d between patients after one cyclodiode session and those eyes that underwe nt additional sessions. Mean baseline IOP was significantly higher in patie nts with intraoperative occurrence of pops. An audible pop was more common in the group undergoing palliative treatment. Intraoperative occurrence of pops was associated with a greater severity of postoperative iridocyclitis. All patients with postoperative hyphema also had pops during surgery. No s ignificant difference in the success rate was found between patients in who m intraoperative pops did and did not occur. Conclusion: Choroidal vaporization is significantly more common in patients with higher baseline IOP. Occurrence of pops also is associated with more severe postoperative inflammation and with a greater risk of postoperative hyphema.