Bleb analysis by using anterior segment optical coherence tomography in two different methods of trabeculectomy

Area of Science:

• Ophthalmology
• Glaucoma Surgery
• Surgical Outcomes

Background:

• Trabeculectomy (TLE) is a key glaucoma surgery.
• Assessing bleb morphology is crucial for predicting intraocular pressure (IOP) control.
• Standardized grading scales and advanced imaging like AS-OCT can enhance bleb assessment.

Purpose of the Study:

• To correlate bleb morphology with IOP control after two TLE techniques.
• To compare the utility of the Indiana Bleb Appearance Grading Scale (IBAGS) and AS-OCT in assessing bleb characteristics.
• To investigate differences in bleb morphology-IOP control relationships between limbal-based and fornix-based TLE.

Main Methods:

• 94 eyes with primary open-angle glaucoma underwent either limbal-based (n=62) or fornix-based (n=32) TLE.
• IOP control defined as IOP ≤ 20 mm Hg with ≥20% reduction from baseline.
• Bleb morphology evaluated using IBAGS and AS-OCT (height, extent, wall thickness, CCD, LUSF).

Main Results:

• Both TLE groups achieved similar success rates.
• In limbal-based TLE, bleb extent and Seidel sign (IBAGS) and bleb height, extent, and thin wall (AS-OCT) correlated with IOP control.
• In fornix-based TLE, only ciliochoroidal detachment (CCD) and/or lake under the scleral flap (LUSF) showed significance with IOP control.

Conclusions:

• Limbal-based TLE success appears more influenced by larger bleb size and thinner bleb walls.
• Fornix-based TLE success may rely less on specific morphological features assessed by IBAGS and AS-OCT.
• Further research may refine the use of imaging and grading scales for predicting TLE outcomes.