Continuous wave transscleral cyclophotocoagulation with the slow-cooking protocol to treat refractory glaucomas

Abstract

Purpose

This study aimed to describe the results of slow-cooking transscleral cyclophotocoagulation (SC-TSCP) with diode laser in patients with refractory glaucoma.

Methods

This retrospective study included 289 eyes of 263 patients who underwent the SC-TSCP technique at the glaucoma service of Oculare Ophthalmology Hospital, Brazil, with a minimum of one year of postoperative follow-up. We analyzed intraocular pressure, number of medications, postoperative complications, visual acuity, need for additional glaucoma surgery, need for repeat sessions of SC-TSCP, and the variables influencing success rates. ​​We used three criteria to analyze the technique's success: 1) Final IOP ≤ 21 mmHg, 2) Final IOP between 6 and 21 mmHg, and 3) Reduction of at least 30% in IOP.

Results

Mean IOP dropped from 37.52 (±12.12) mmHg preoperatively to 14.48 (± 7.56) mmHg at the end of the study (p = 0.0001). The average reduction in IOP was 23.04 (±14.00) mmHg, representing a reduction of 61.41% in IOP (p = 0.0001). The mean number of medications dropped from 2.98 (±1.43) to 1.79 (±1.50) (p = 0.0001). Complete success (without eyedrops) was achieved in 25.61%, 18.69%, and 29.41% for each success criterion, and qualified success (with or without eyedrops) was achieved in 79.58%, 68.86%, and 85.43%, respectively. Visual acuity decreased from 1.99 LogMar (Snellen 20/1954) to 2.11 LogMar (Snellen 20/2576) (p = 0.0001). Seventy-two eyes (24.91%) needed a second session, 15 eyes (5.19%) needed a third cyclophotocoagulation, and one eye (0.35%) needed a fourth session. The most common complications were persistent hypotony (8.65%), corneal decompensation (6.23%), loss of light perception (5.88%), and phthisis (2.77%). After cyclophotocoagulation, 86.85% of the eyes did not require additional surgical procedures for IOP control.

Conclusion

The slow-cooking transscleral cyclophotocoagulation technique proved highly effective in the prolonged control of intraocular pressure in severe and refractory glaucoma and demonstrated a favourable safety profile. However, in complex and refractory cases, severe complications such as vision loss or phthisis, although rare, may occur.