Abstract
Purpose :
To evaluate the effectiveness and safety of Micropulse Transscleral Cyclophotocoagulation (MP-TSCPC, Iridex Corp, Mountain View, CA) in adults at 6 months based on variable treatment duration while keeping other parameters fixed.
Methods :
A retrospective observational study was performed. All patients who underwent a MP-TSCPC in three different glaucoma centers in the 2016-2017 period, with at least 6 months of follow-up were included. We used 3 different treatment durations (100, 160 and 180 seconds to treat the whole eye – 360 degrees) and kept laser power at 2 watts and ON cycle at 0.5ms (31.3%).
Success was defined as a reduction in preoperative IOP of at least 20% and an IOP ≤ 21 mmHg in the last visit compared to baseline, with no additional surgical treatment. Log-rank test was used to test statistical difference between groups. Paired t-test was used to test the mean IOP reduction in successful patients.
Results :
A total of 22 eyes of 17 patients with complex glaucoma were treated with MP-TSCPC. Mean follow-up time was 7.45 months. Diagnosis were congenital glaucoma: 7 (32%), pseudoexfoliation glaucoma: 5 (23%), aphakic glaucoma: 3 (14%) and miscellaneous glaucoma 7 (32%). Mean age was 46.2 years (range 11-79) and 8 (47%) were female. Total treatment duration was 100 seconds (s) in 4 eyes, 160s in 14 eyes and 180s in 4 eyes. Laser power was fixed at 2 Watts. Treatment location was throughout 360 degrees with an ON cycle of 0.5ms (31.3%).
Success rate was 25% in the 100s group, 50% in the 160s group and 100% in the 180s group at 4 months; 0%, 42.9% and 75% at 6 months; and 0%, 21.4% and 75% in the last visit (7.45 months), respectively. A statistically significant difference among treatment duration groups was found (p=0.002).
Mean IOP reduction was 36% (9.7 mmHg, SD 4.58; p=0.001) at final follow-up. No complications were reported.
Conclusions :
When the remaining parameters are fixed, MP-TSCPC mid-term success rate varies significantly depending on treatment duration. At last timepoint, 180s of treatment duration appears to be moderate effective and equally safe at reducing IOP, when compared to lower treatment durations. 100s of treatment are able to lower the IOP in the short-term, but the effect decreases significantly as it approaches six months.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.