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Abstract #77302 Published in IGR 19-3
Is Ahmed Glaucoma Valve Consistent in Performance?
Choudhari NS; Badakere SV; Richhariya A; Chittajallu SNSH; Senthil S; Garudadri CSTranslational vision science & technology 2018; 7: 19
PURPOSE: To investigate the mechanism of action and consistency in flow characteristics of the Ahmed glaucoma valve (AGV) under simulated physiological conditions in-vitro and to evaluate whether resistance during priming has any effect on performance of the device. METHODS: Each newly opened AGV device was connected to a digital manometer and was primed with normal saline. The device was then placed in a saline bath and connected to an open manometer, a digital manometer, and an infusion pump. Saline was infused at a rate of 3 μL/min for 24 hours. Digital manometer readings were recorded at 4 Hz. RESULTS: Data obtained from 9 devices are presented as medians (ranges). The priming pressure was 1130 (835, 1625) mm Hg. Pressure versus time curves showed two distinct phases; transient and steady phases. The transient phase peak pressure was 24 (13, 45) mm Hg. In the steady phase, opening and closing pressures were 13 (10, 17) and 7 (4, 9) mm Hg, respectively; the valve leaflets briefly opened every 73.9 (51, 76.6) minutes and the fluctuation of pressure (difference between opening and closing pressures) was 6 (3, 9) mm Hg. The Spearman correlation coefficient between priming and opening and priming and closing pressure was ρ = -0.13 ( = 0.72) and ρ = -0.36 ( = 0.33), respectively. CONCLUSIONS: The device showed functionality like a valve. The resistance during priming did not affect opening and closing pressures of the AGV. This study showed variable in vitro performance of the AGV. TRANSLATIONAL RELEVANCE: These laboratory findings might, at least partly, explain the variability in the clinical outcome of the device.
VST Glaucoma Centre, Dr. Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, India.
Full articleClassification:
12.8.2 With tube implant or other drainage devices (Part of: 12 Surgical treatment > 12.8 Filtering surgery)
