# Development of a Probability-Based In Vitro Eye Irritation Screening Platform

## TL;DR

A new high-throughput eye irritation screening method uses cell apoptosis and nociceptor activation to predict irritation potential accurately.

## Contribution

A novel probability-based platform integrates multiple mechanistic readouts for accurate and scalable eye irritation prediction.

## Key findings

- Combining apoptosis and TRPV1 activation in micropatterned cell models improves irritation prediction accuracy.
- The method allows high-throughput screening by binarizing and statistically analyzing large datasets from cell responses.

## Abstract

Traditional eye irritation assessments, which rely on animal models or ex vivo tissues, face limitations due to ethical concerns, costs, and low throughput. Although numerous in vitro tests have been developed, none have successfully reconciled the need for high experimental throughput with the accurate prediction of irritation potential, attributable to the complexity of irritation mechanisms. Simple cell models, while suitable for high-throughput screening, offer limited mechanistic insights, contrasting with more physiologically relevant but less scalable complex organotypic corneal tissue constructs. This study presents a novel strategy to enhance the predictive accuracy of screening-compatible simple cell models in eye irritation testing. Our method combines the results of two in vitro assays—cell apoptosis and nociceptor (TRPV1) activation—using micropatterned chips to partition human corneal epithelial cells into numerous discrete small populations. Following exposure to test compounds, we measure apoptosis and nociceptor activation responses. The large datasets collected from the cell micropatterns facilitate binarization and statistical fitting to calculate a mathematical probability, which assesses the compound’s potential to cause eye irritation. This method potentially enables the amalgamation of multiple mechanistic readouts into a singular index, providing a more accurate and reliable prediction of eye irritation potential in a format amenable to high-throughput screening.