Outcomes of two patterns of application of subliminal diode laser cyclophotocoagulation in refractory glaucoma: a prospective study

Purpose To evaluate the efficacy and safety of subliminal subthreshold transscleral diode cyclophotocoagulation in refractory glaucoma, using the standard technique of 360-degree arc-like laser application. As well as the results obtained with a modified zigzag application pattern. Patients and methods A prospective interventional study was conducted on 50 patients with refractory glaucoma. Participants were divided into two groups of 25 patients each. Group A received standard treatment with an arc-like pattern, while group B received a modified zigzag pattern. Intraocular pressure (IOP), visual acuity, number of pressure-lowering medications, and complications were recorded. Success was defined as IOP between 6 and 21 mmHg, or more than or equal to 20% reduction in IOP at the final follow-up after a single session (absolute success) or with retreatment (qualified success). The overall success rate was the sum of both. Results Both groups showed significant reductions in mean IOP after 6 months (41.56±8.36–22.96±8.56 mmHg for group A and 42.08±9.51–21.20±9.45 mmHg for group B, P <0.0001). Overall success rate was 76.0% in group A and 84.0% in group B. Antiglaucoma medications were significantly reduced. No significant change in best corrected visual acuity was observed. Transient anterior chamber inflammation occurred in four patients in group A and six in group B. No major complications were reported. Conclusion Subliminal subthreshold transscleral diode cyclophotocoagulation, applied in an arc-like or zigzag pattern, demonstrated promising results with a reasonable safety profile. Total energy in the range of 150–200 J may offer an appropriate balance between efficacy and safety. Further large-scale, long-term studies are warranted to confirm these findings.