# A Revised Concept for Ocular Surface Imprinting: Easy-to-Use Device for Morphological and Biomolecular-Based Differential Diagnosis

## TL;DR

This paper introduces a new device for easily collecting cells from the eye's surface to help with diagnosis in ophthalmology.

## Contribution

A new, easy-to-use ocular surface sampling device (SurfAL pen) is introduced and validated for clinical use.

## Key findings

- The SurfAL pen allows quick and reproducible sampling of corneal and conjunctival epithelial cells.
- The device was found to be suitable for routine analysis and comparable to conventional methods in terms of cell detection.
- The periocular-assisted SurfAL pen had similar sampling quality but lower user confidence due to its design.

## Abstract

Background/objectives: The continuous necessity to support biostrumental data with biolomecular data collected using non-invasive tools is influencing the world of ocular surface devices. The ocular imprint still represents a non-invasive and safety technique for collecting corneal and conjunctival epithelia in an easy way, as performed in human and veterinary clinics. Although used in clinical practice since 1977, operators might benefit from improvements in these techniques, especially in terms of handling and management. Methods: Herein, by reporting the design and characteristics of a patent of ocular surface sampling (the SurfAL pen and periocular-assisted SurfAL pen; PCT WO2016IB51474 20160316), we performed a validation and analysis of its value compared to gold standards. The level-headedness and advantages of this device were verified in 15 sclerocorneal specimens (sampling advantages) and tested in 25 volunteers (handling and operator efficiency, as well as frequency of discomfort in volunteers). Morphological as well as biomolecular analyses were used to compare SurfAL devices with conventional ones. Results: The easy management of SurfAL pens and the good detection of epithelial/goblet cells were confirmed. The SurfAL pen was found to be smart and suitable for routine analysis, as confirmed by quick and reproducible onsite sampling. Periocular-assisted SurfAL pen was comparable in terms of sampling quality but less comparable in terms of subject confidence due to its geometry. Conclusions: This study suggests that the SurfAL pen and periocular-assisted SurfAL pen might represent an additional and hands-on way of sampling ocular surface cells and improve the diagnostic route in ophthalmology.