Strength characterization of Human Cornea Against Sutures: Experiments

Abstract

Purpose : To investigate the break starting strength (BSS) of human cornea inline with ISO: 7198 – 2016 to evaluate the suture tolerating strength of the cornea without losing its functionality.

Methods : 10 corneas with a suture bite distance of 2 mm from limbus were tested for a suture pullout test at a pulling rate of 3 mm/min. A lower pulling rate was used in the tests considering the physiology of the human eye. A steel wire of 0.4 mm is used for testing to negate the elastic effects of the sutures as per ISO 7198 – 2016. Tests were carried in a universal tensile testing machine with a 10 N load cell. Specimens were imaged while testing with the help of a microscopic imaging system with 16X magnification.

Results : BSS of the cornea is 4.072±0.859 N found at a 3 mm/min pull rate. The 10 N load cell is sensitive enough to capture the BSS, and the imaging system helps in situations where BSS is not visible in the load vs. time curve. The present system is efficient enough to evaluate BSS.

Conclusions : BSS of the cornea is evaluated with the help of a robust experimental setup.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

(a) Experimental setup for evaluating BSS it contains 1 UTM, 2 specimen, 3 external illumination, 4 camera attached to 5 a microscope and experiment is captured in a laptop 6 and (b) Specimen containing 7 steel-string, 8 tear cased due to pull and 9 is the human cornea.

 

Load vs time curves indicating the BSS