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New cost-effective in-vivo corneal biomechanics analysis: a numerical simulation

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First Author: B.Lopes UK

Co Author(s):    A. Eliasy   A. Abass   A. Elsheikh              

Abstract Details

Purpose:

To evaluate the ability of obtaining accurate corneal material properties and intraocular pressure (IOP) based on corneal deformation under air-puff pressure monitored at nine points across the anterior surface.

Setting:

University of Liverpool

Methods:

The full-eye clinically validated finite element model of the BioEG (University Liverpool) was used in a parametric study including 2,300 healthy-eye models. Central corneal thickness ranged from 395 to 645µm, central curvature radius from 7.2 to 8.4mm, IOP from 10 to 30mmHg and stress-strain index (SSI) from 0.25 to 2.0. A cost-effective standard diode laser measurable displacement under air-puff pressure of 90mmHg was monitored at nine anterior surface corneal points, one located at the apex and eight radially distributed 1.1mm away from the apex at 45-degree intervals. An equation able to predict the SSI and the IOP was derived.

Results:

Both corneal material properties by means of the SSI and the IOP predicted by the equations were highly correlated with the actual values. For the corneal material properties, the correlation coefficient was R2=0.99, the Root Mean Square Error (RMSE) was 0.03 and the maximum difference between the predicted and the actual value of SSI was 0.21. The R2 value for IOP was also 0.99, RMSE=0.40 mmHg and maximum difference between predicted and actual value was 2 mmHg.

Conclusions:

The in-silico results demonstrate that IOP and corneal material properties can be predicted with reasonable accuracy by using limited measurements of corneal deformation obtainable with a cost-effect clinically safe-to-use standard laser diode system. Experimental investigation is being carried out to implement this technology in a new cost-effective in-vivo biomechanical device.

Financial Disclosure:

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