Abstract
Purpose :
Compare intracameral transducer pressure with intraocular pressure (IOP) measured by both a standard Latex cover and an IOP tunable silicone cover on a tonopen-type tonometer with validation by comparison to a standard Goldmann.
Methods :
A synthetic corneal membrane Goldmann IOP measurement training globe was manometrically pressurized between 5 and 60 mmHg by fluid column and measured by transducer. Intraocular pressure was measured sequentially at each intracameral pressure setting using both Latex and concave-surfaced tunable silicone covers on a tonopen-type handheld tonometer. The height of the silicone cover central concavity was altered between 0 and 200 microns and correlated to IOP measurement by the tonopen-type device.
Results :
IOP measurements produced by the 100 micron depth concave silicone cover produced insignificant overall intracameral comparison bias and insignificant Goldmann IOP bias at -2.43±4.84 mmHg (p=0.35) and +0.31+/-4.40mmHg (p=0.42), respectively. The standard Latex cover IOP measurement demonstrated the largest IOP measurement bias compared to intracameral pressure at -13.0±5.05mmHg (p≤0.0001). An underestimation IOP measurement error increased significantly at higher intracameral pressures with all modalities. The silicone cover concavity depth correlated to increased IOP measurement by the tonopen-type tonometer at a fixed intracameral pressure of 20mmHg (p=0.05).
Conclusions :
A concave silicone cover for a tonopen-type tonometer may significantly improve IOP accuracy and could be tuned for racial or species specific bias.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.