9. MORPHOLOGY OF FILTERING BLEB AFTER AHMED VALVE GLAUCOMA SURGERY USING ANTERIOR SEGMENT OPTICAL COHERENCE TOMOGRAPHY
Main Article Content
Abstract
Purposes: To assess the morphology of filtering bleb after Ahmed valve glaucoma surgery using anterior segment optical coherence tomography (AS-OCT) and propose a classification system for bleb according to clinical and AS-OCT parameters.
Methods: A total of 48 patients who had received Ahmed valve implantation participated in this prospective study. Clinical morphology and AS-OCT parameters were measured post-operatively at 1 week, 1 month, 3 months and 6 months. The relationship between the bleb morphology and success of the surgery was evaluated. Success was defined as IOP < 21 mmHg with a maximum of 2 glaucoma medications.
Results: Photographic standards illustrating clinical bleb morphology characteristics was selected from the clinical images in the study. Bleb vascularity and color was significantly correlated with the hypertensive phase and surgery success (p<0.05). Bleb analysis using AS-OCT revealed a significant reduction in bleb wall thickness and increase in bleb wall reflectivity at 1 month, which was mostly associated with hypertensive phase. There was a significant correlation between AS-OCT parameters (bleb wall thickness, bleb wall reflectivity, bleb height, microcyst) and surgery success (p<0.05).
Conclusions: The morphology of filtering bleb based on clinical image and AS-OCT parameters shows significant correlation with the surgery success and hypertensive phase incdence. This leads to potential usage of bleb classification in analysis and prediction of Ahmed valve implantation outcome.
Article Details
Keywords
Ahmed valve glaucoma surgery, bleb, AS-OCT
References
[2] Wagdy, F.M., Bleb Morphology Using Anterior-Segment Optical Coherence Tomography after Ahmed Glaucoma Valve Surgery with Tenon Capsule Resection. J Ophthalmol, 2020. 2020: tr. 8386135.
[3] Cantor, L.B., et al., Morphologic classification of filtering blebs after glaucoma filtration surgery: the Indiana Bleb Appearance Grading Scale. J Glaucoma, 2003. 12 (3): tr. 266-71.
[4] Freedman, J. and P. Iserovich, Pro-inflammatory cytokines in glaucomatous aqueous and encysted Molteno implant blebs and their relationship to pressure. Invest Ophthalmol Vis Sci, 2013. 54 (7): tr. 4851-5.
[5] Jung, K.I., et al., Serial changes in the bleb wall after glaucoma drainage implant surgery: Characteristics during the hypertensive phase. Acta Ophthalmol, 2015. 93 (4): tr. e248-53.
[6] Mathew-Steiner, S.S., S. Roy, and C.K. Sen, Collagen in Wound Healing. Bioengineering (Basel), 2021. 8 (5).
[7] Rho, S., et al., Bleb Analysis and Short-Term Results of Biodegradable Collagen Matrix-Augmented Ahmed Glaucoma Valve Implantation: 6-Month Follow-up. Invest Ophthalmol Vis Sci, 2015. 56 (10): tr. 5896-903.