Distinctive Intrableb Structures of Functioning Blebs following Trabeculectomy according to Amniotic Membrane...

Intrableb structures are hallmark features of the filtering bleb. This study aimed to compare the characteristics of functioning blebs using anterior segment optical coherence tomography (AS-OCT) according to amniotic membrane transplantation (AMT).

Forty eyes from 40 patients diagnosed with primary open-angle glaucoma who underwent trabeculectomy, either with AMT (20 eyes) or without AMT (control group, 20 eyes), were included. Parameters including bleb height, bleb wall thickness, striping layer thickness, striping to bleb wall ratio, bleb wall reflectivity, fluid-filled space score/height/area, and presence of microcysts were assessed using AS-OCT. Surgical success was defined at the time of AS-OCT as an intraocular pressure (IOP) ≤18 mm Hg and IOP reduction ≥30% without medication. In these patients, if the bleb had a clinically diffuse and healthy without any signs of an encapsulated bleb, the bleb was then defined as functioning bleb.

Except for bleb height (p = 0.352) and microcyst formation (p = 0.266), significant differences were observed between the two groups. The functioning blebs of the AMT group exhibited greater fluid-filled space score, area, and height than those of the control group, following adjustment for AS-OCT time (all p < 0.001). Conversely, the functioning bleb of the control group demonstrated thicker bleb wall and striping layer, higher striping to bleb wall ratio, and lower bleb wall reflectivity than those of the AMT group, following adjustment for AS-OCT time (all p ≤ 0.001).

Distinct intrableb structures were identified in functioning blebs according to AMT. The reflectivity and thickness of the bleb wall structures were more pronounced in the functioning bleb after trabeculectomy alone. In contrast, the extent of the fluid-filled space emerged as a more distinctive feature of the intrableb structures in the functioning bleb after trabeculectomy with AMT.