Abstract:A transient 3D fluid-structure interaction model of non-contact tonometer′s cornea applanation process has been built to study the external flow field of non-contact tonometer and the dynamic corneal deformation with different intraocular pressure. The results show that the flow field satisfies jet flow theory by showing certain characteristics like the potential core and outer jet boundary; the outer jet boundary of the non-contact tonometer air-puff is around 8.4° which does not change over time, while the jet core decrease from 4.9° to 4.6° over time; the applanation time of cornea increase with intraocular pressure while the applanation length remains in 3.2~3.6mm,which is consistent with the data on the applanation diameter of the non-contact tonometer in the relevant literature. Furthermore, an in-house made experimental device for phantom of intraocular pressure is used to compare results with different applanation length. The results show that comparatively small applanation length will cause severe deviation of intraocular pressure measurement up to 665Pa, which also matches with the simulation result.
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