Evaluation of diode laser cyclophotocoagulation efficiency in refractory glaucoma and determination of structural changes using ultrasound biomicroscopy.

Abstract

Purpose: To evaluate the effect of single-session transscleral diode laser cyclophotocoagulation on intraocular pressure in refractory glaucoma and to determine structural changes using ultrasound biomicroscopy.

Methods: Forty-three eyes were evaluated. Intraocular pressures at baseline and at the first, third, and sixth months after transscleral diode laser cyclophotocoagulation were compared. Ciliary body thickness, ciliary muscle thickness, ciliary process thickness, iris root thickness, and scleral thickness were assessed at baseline and at the third and sixth months post-treatment.

Results: Reductions in intraocular pressure were significant between baseline and the first month (p=0.018), third month (p<0.001), and sixth month (p<0.001) as well as between the first and third months (p=0.034) and the first and sixth months (p=0.036). Compared with baseline, intraocular pressure reduction rates at the first, third, and sixth months were 34.6%, 56.5%, and 55.3%, respectively, while success rates were 30.2%, 62.8%, and 55.8%, respectively. Decreases in ciliary body thickness, ciliary muscle thickness, and ciliary process thickness were significant between baseline and the third month (p<0.05) and between baseline and the sixth month (p<0.05), whereas changes between the third and sixth months were not significant (p>0.05). Iris root and scleral thicknesses did not change after treatment (p>0.05). At the third and sixth months, significant positive correlations were observed between changes in intraocular pressure and changes in ciliary body thickness and ciliary process thickness (p<0.05).

Conclusions: To the best of our knowledge, this is one of the few studies comprehensively investigating structural changes after transscleral diode laser cyclophotocoagulation using ultrasound biomicroscopy. Moreover, the relationships between intraocular pressure changes and variations in the ciliary body, ciliary muscle, ciliary process, iris root, and scleral thicknesses were examined in detail. Single-session treatment did not affect iris root or scleral thickness but significantly reduced ciliary body, ciliary muscle, and ciliary process thicknesses. Greater reductions in ciliary body and ciliary process thickness may contribute to more pronounced intraocular pressure reduction.