Purchase this article with an account.
Hendrik Walther, Vivian WY Chan, Chau-Minh Phan, Lyndon William Jones; Modelling non-invasive tear break-up times of soft lenses using a sophisticated in vitroblink platform. Invest. Ophthalmol. Vis. Sci. 2019;60(9):6328.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To evaluate the feasibility of a novel in vitroeye model to determine the pre-lens non-invasivetear breakup times (NIBUT) of two daily disposable (DD) contact lenses (CLs).
An artificial eyeball synthesized from polyvinyl alcohol (15% w/t, 89-98 kDa) was used on a novel in vitroeye model (OcuBlink), incorporating a blink and constant tear flow. A flat black disc was incorporated into the eyeball for contrast. The OcuBlink’s flexible eyelid design ensures contact with the eyeball, thereby enabling an even spread of the tear solution over the front of the CL. The blink interval was set to 10 seconds, and the flow rate of an artificial tear solution was set to 1.4 µL/min. A silicone hydrogel (SH; delefilcon A), and conventional hydrogel (CH; nelfilcon A) DD were placed over the corneal section and the NIBUT was evaluated after 1 h of blinking. A corneal topographer (Atlas, Zeiss Canada) was used to illuminate the lens surfaces andcapture changes of the placido ring images. The humidity during the experiment was between 22-23%.
A stable artificial tear film layer was formed over the artificial eyeball and the CLs. This layer was regenerated after each blink. The NIBUTs for delfilcon A, nelfilcon A, and the artificial eyeball were 7.55 ± 1.59 seconds, 8.16 ± 0.81 seconds, and 5.13 ± 0.09 seconds respectively. There were no significant differences between the two lens types (p>0.05), and between nelfilcon A and the artificial eyeball (p>0.05). However, delfilcon A had a longer NIBUT than the artificial eyeball (p<0.05).
The measured NIBUT values over the artificial eyeball and CLs are similar to those found in vivo. The OcuBlink simulates the blink motion and physiological tear flow rates, and could be used to measure in vitropre-lens NIBUT values for various CLs.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
Figure 1: OcuBlink in front of a topographer
Figure 2: Eye surface after 1 blink and surface with tear break up
This PDF is available to Subscribers Only