Deep sclerectomy versus trabeculectomy: a morphological study with anterior segment optical coherence tomography

• Published in: British journal of ophthalmology Vol. 97; no. 6; pp. 708 - 714
• Main Authors: Konstantopoulos, Aris, Yadegarfar, Mohammad E, Yadegarfar, Ghasem, Stinghe, Alina, Macleod, Alex, Jacob, Aby, Hossain, Parwez
• Format: Journal Article
• Language: English
• Published: BMA House, Tavistock Square, London, WC1H 9JR BMJ Publishing Group Ltd 01.06.2013; BMJ Publishing Group LTD
• Subjects: Aged; Aged, 80 and over; Anterior Eye Segment - pathology; Anterior Eye Segment - surgery; Conjunctiva - pathology; Conjunctiva - surgery; Cross-Sectional Studies; Drainage; Female; Glaucoma; Glaucoma - pathology; Glaucoma - surgery; Humans; Imaging; Intraocular Pressure; Male; Medical imaging; Microscopy; Middle Aged; Morphology; Ostomy; Postoperative period; Prospective Studies; Sclera - surgery; Success; Surgery; Surgical Flaps; Tenon Capsule - pathology; Tenon Capsule - surgery; Tomography, Optical Coherence; Trabecular Meshwork - surgery; Trabeculectomy - methods; Treatment Outcome; Glaucoma; Imaging
• ISSN: 0007-1161; 1468-2079
• DOI: 10.1136/bjophthalmol-2012-301926

Purpose To investigate the intraocular pressure (IOP) lowering mechanisms of deep sclerectomy (DS) with anterior segment optical coherence tomography (AS-OCT). Methods In a prospective cross-sectional study, AS-OCT parameters were compared between DS, trabeculectomy and control cases. Association with IOP and success (IOP≤16 mm Hg without medication) was investigated. Results 18 DS (15 patients), 17 trabeculectomy (16 patients) and 15 controls (15 patients) were examined. Successful had a taller intrascleral lake (IL) and thicker conjunctival/Tenon's layer (CTL) than non-successful cases (513.3 vs 361.1 µm, p=0.027 and 586.7 vs 251.1 µm, p<0.001, respectively). CTL thickness correlated with IOP (r=−0.6407, p=0.004). CTL thickness was significantly different between controls, DS and trabeculectomy (mean (SD): 203.3 (62.6) vs 418.9 (261.9) vs 604.1 (220.7) µm, p<0.0001). Successful trabeculectomy cases had a taller bleb cavity (BC) than non-successful cases (607.5 vs 176.7 µm, p=0.041). CTL microcysts were detected in 50% of DS and 52.9% of trabeculectomy cases (p=1). Conclusions Trans-conjunctival aqueous percolation was identified as a novel DS drainage route. DS had a fluid reservoir below the scleral flap, the IL, in analogy to the trabeculectomy BC. A postoperative tall IL and a thick CTL were associated with good outcome.