Abstract
Purpose :
This prospective observational clinical study compares immediate postoperative intraocular pressure (IOP) between continuous wave transscleral diode cyclophotocoagulation (CW-TSCPC) and micropulse transscleral diode cyclophotocoagulation (MP-TSCPC).
Methods :
CW-TSCPC was performed applying 20 laser spots for 2000 ms at 2000 mw. MP-TSCPC was applied for 160-seconds at 2500 mW with a duty cycle of 31.3%. IOP was measured at baseline, 1, 3, 5, and 24 hours after TSCPC using Goldmann applanation tonometry. Acetazolamide was selectively administered to patients with IOP >30 mmHg or IOP >25 mmHg and experiencing pain.
Results :
67 patients were included (31 male 36 female; average age 76±12 years). 30 patients were treated with CW-TSCPC and 37 with MP-TSCPC. Average age was 75±11 in the CW-TSCPC and 76±12 in MP-TSCPC group (p=0.519, Mann-Whitney U Test). Baseline IOP showed no difference between groups (19±7 vs. 18±6 mmHg; p=0.530, t-test). One hour after CW-TSCPC IOP increased significantly higher compared to MP-TSCPC group (22±7 vs. 17±6 mmHg; p<0.01). This increase in IOP persisted 3 hours (24±8 vs. 18±5 mmHg p<0.001) and 5 hours (22±6 vs. 17±5 mmHg; p<0.01) after treatment. There was no significant difference in IOP (14±6 vs. 14±4 mmHg; p=0.763) 24 hours after treatment. Within CW-TSCPC group significant increase of IOP was observed 1 and 3 hours after treatment compared to baseline (p<0.01, paired t-test). No significant increase in IOP was measured after MP-TSCPC compared to baseline (p>0.05). Significantly less patients (1/37; 3%) after MP-TSCPC needed acetazolamide compared to after CW-TSCPC (5/30, 17%; p<0.05). In patients undergoing MP-TSCPC, blue-eyed individuals showed significantly higher IOP 1 hour post-treatment compared to those with brown (p<0.05) and grey eyes (p<0.05). No notable IOP differences based on iris color were observed at other times in both groups.
Conclusions :
A significantly higher increase in IOP 1,3, and 5 hours after CW-TSCPC was shown compared to MP-TSCPC. Patients that underwent CW-TSCPC required more concomitant medication. MP-TSCPC showed less risk of short-term increase in postoperative IOP while achieving similar IOP values after 24 hours. We strongly advice conducting postoperative IOP measurements at several timepoints for patients undergoing CW-TSCPC due to the risk of postoperative IOP increase.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.