Transscleral Laser Cyclothermotherapy in the Treatment of Primary Open-angle Glaucoma: Predictors of Effectiveness

Objectives: to evaluate the prognostic significance of early postoperative inflammatory response parameters, namely visible aqueous

humor opalescence and ciliary body thickness increase, for the effectiveness of transscleral laser cyclothermotherapy (TLCTT) in patients with primary open-angle glaucoma. 

Patients and methods. A retrospective analysis included 33 patients (22 men, 11 women; mean age 72.4 years) with uncontrolled primary open-angle glaucoma despite maximally tolerated hypotensive therapy. TLCTT was performed under local anesthesia with up to 16 applications delivered in the mode of 0.5 W for 20 s. Optical coherence tomography (CASIA2, Tomey, Japan) was used to assess ciliary body thickness before surgery and on postoperative day 1. Presence of aqueous humor opalescence was also recorded on day 1. Intraocular pressure (IOP) was measured by Maklakov tonometry, and topical regimen was documented preoperatively and at 1, 3, 6, and 12 months. Treatment success was defined as IOP reduction ≥ 20 % starting from 1 month.

Results. Mean IOP reduction at 12 months was 8.8 ± 3.9 mmHg, corresponding to 23.8 % (p < 0.001). Treatment success was achieved in 24 patients (72.7 %). Visible aqueous humor opalescence on day 1 was observed in 24 patients (72.7 %) and correlated positively with greater IOP reduction (p = 0.008, r = 0.72). Ciliary body thickness increased significantly on day 1 postoperatively (p < 0.0001). The dynamics of thickness increase showed a strong positive correlation with IOP reduction (r = 0.86, p < 0.05). 

Conclusion. Early postoperative signs of intraocular inflammation and ciliary body edema can serve as reliable predictors of TLCTT effectiveness. Visible aqueous humor opalescence and increased ciliary body thickness on day 1 are associated with higher likelihood of achieving a sustained hypotensive effect within 1 month. These parameters may be recommended for early prediction of treatment outcomes in patients undergoing TLCTT for primary open-angle glaucoma.

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