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Abstract #91836 Published in IGR 21-4
Quantification of Translaminar Pressure Gradient (TLPG) With Continuous Wireless Telemetry in Nonhuman Primates (NHPs)
Jasien JV; Fazio MA; Samuels BC; Johnston JM; Downs JCTranslational vision science & technology 2020; 9: 18
PURPOSE: Recent retrospective clinical and animal studies suggest that cerebrospinal fluid pressure (CSFP) is important in glaucoma pathogenesis. Intraocular pressure (IOP) and CSFP are the driving components of translaminar pressure (TLP = IOP - CSFP), which acts across the lamina cribrosa (LC) thickness to create the translaminar pressure gradient (TLPG = TLP/LC thickness). METHODS: We developed an implantable wireless telemetry system based on a small piezoelectric sensor with low temporal drift. IOP, measured in the anterior chamber, and intracranial pressure (ICP), measured in the brain parenchyma (as a surrogate for CSFP) were measured at 200 Hz in three male rhesus macaques (nonhuman primates, NHPs) on a 10% duty cycle (15 seconds of every 150-second period). Three-dimensional LC thickness was autosegmented as the mean thickness of the visible hyperreflective band in 48 radial spectral-domain optical coherence tomography b-scans centered on the optic nerve head. RESULTS: Results indicated the rank order of IOP, ICP, TLP, and TLPG for waking, sleeping, and 24-hour periods averaged across all days. NHP 150110 had the highest IOP and ICP in all periods; however, it had the lowest TLPG in all periods due to its relatively thick LC. The other two NHPs showed similar shifts in the rank order of possible glaucoma risk factors. CONCLUSIONS: IOP is the only modifiable and readily measurable pressure-based risk factor for glaucoma. However, other potential risk factors such as ICP, TLP, and TLPG, as well as their rank-order patterns, differed compared to IOP across subjects, demonstrating that a comprehensive view of relevant risk factors is warranted. TRANSLATIONAL RELEVANCE: Future studies should consider including CSFP, TLP, and TLPG in addition to IOP as potential risk factors when assessing eye-specific glaucoma susceptibility.
Vision Science Graduate Program, School of Optometry, The University of Alabama at Birmingham, Birmingham, AL, USA.
Full articleClassification:
5.2 Primates (Part of: 5 Experimental glaucoma; animal models)
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
2.15 Optic nerve (Part of: 2 Anatomical structures in glaucoma)
6.19 Telemedicine (Part of: 6 Clinical examination methods)