An eye phantom for the testing of eye drop instillation devices

Introduction

Eye conditions such as glaucoma, dry eye, and age-related macular degeneration can cause irreversible visual impairment. Effective treatment with eye drops can help to slow disease progression, alleviate symptoms, and preserve vision
1. For people who have physical disabilities, the self-installation of eye drops can be a  challenging task due to difficulties intrinsic in eye drop administration technique, in addition to other factors, such as fear of eye drops and movement difficulties.
2. Assistive devices for eye drop self-installation are available commercially. However, it has been empirically observed that the adoption of these devices is poor, and that patients do not like them.
3. Yet, to our knowledge, no standardized testing method for the evaluation of eye drop instillation devices exists to date.
With this work, we wish to present a phantom of the eye and periorbital region, that we are developing specifically to explore whether a set of objective performance parameters can be established for eye drop delivery devices, and to use in our own internal development of such devices.
At this stage, we are designing the phantom to be able to test the devices for mechanical fit to the eye and orbit, for alignment of the drop delivery path with the eye, for the neck posture requirements, and for quantitative evaluation of the delivery efficiency.

Methods

The phantom consists of a 3D-printed section, mimicking the left eye and periorbital region, 3D printed in polylactic acid using fused-filament fabrication. In the present iteration, the geometry of the head follows established mixed-race male anthropometry4, albeit this will be extended to further population groups for better inclusivity as soon as suitable anthropometric data will be identified. This section is assembled on a modular aluminum strut platform, that can be reconfigured for the control of the effective posture.
The aluminum struts lend themselves to the simple installation of measurement devices and, indeed, in the immediate future we are planning to include a camera for fit and alignment measurement, and either an optical mire or a digital goniometer for posture measurement.
The eye region is hollowed out, to allow drop collection for delivery efficiency determination.

Results & Discussion

The 3D-printed section and the strut platform are currently in the assembly phase, aiming to proceed to the installation of the camera and optical mire over the oncoming weeks. At the conference, an update on the status of the phantom will be presented.

Acknowledgements

This work was supported by the Dunhill Medical Trust [grant number PDM2202\29], and by the Government of Thailand