In comparison to artificial tears or eye drops, human tears are considerably more intricate liquids, containing a diverse range of components such as lipids, carbohydrates, proteins, water, and salt. This intricate mixture is responsible for the optimal viscosity and moisturizing ability of tears, a complex design that is challenging to replicate using fewer ingredients.
In a study published in Physics of Fluids by Vega et al., conducted by AIP Publishing, researchers delved into the micron-level analysis of human tears to uncover new methods of customizing artificial tears that specifically address individual symptoms associated with dry eye disease. The comprehensive understanding gained regarding tear composition and behavior has the potential to be applied to the investigation of ocular pathogens and other biological fluids.
"Tailoring formulations and characteristics to meet individual requirements are key considerations in achieving efficacy," author Juan F. Vega said. "The ultimate goal is to provide an effective and personalized solution that alleviates dry eye syndrome."
The authors conducted experiments involving the collection of healthy human tears and the testing of 10 different formulations of artificial tears. They aimed to understand various properties of these liquids, including viscosity (flow), elasticity, stability, and the impact of different component concentrations. Furthermore, they examined the behavior of the liquids when subjected to stress, such as during blinking of the eye.
To investigate the small liquid volumes present in tears, the authors employed microrheology methods. These methods monitor the movement of micron-sized particles within liquids and utilize dynamic light scattering (DLS) techniques. By analyzing how light reflects off suspended particles, they were able to observe and study the behavior of the liquid in different scenarios.
The authors' innovative application of these methods to the study of tears holds significance for enhancing fundamental knowledge of microbiological fluids and designing functional materials with specific desired properties. This research has the potential to contribute to advancements in various fields.
"The goal of investigating these characteristics is to understand the behavior of the fluid and gain insights into its performance and potential applications – for example, cosmetics, pharmaceuticals, or food – where understanding the viscoelastic properties helps in formulating products with desirable textures, stability, and flow behavior," Vega said.
The authors intend to further investigate and develop more intricate formulations of artificial tears. Additionally, they aim to expand their research to encompass the study of human tears associated with various pathological conditions.
"Through careful tuning, artificial tears can be tailored to meet specific needs, such as stability, lubrication, and moisturization, and mimicking natural tears," Vega said. "Ultimately, this work aims to enhance the comfort and well-being of individuals experiencing dry eye symptoms."
Breaking Into Tears with Microrheology to Design Custom Eye Drops: https://publishing.aip.org/publications/latest-content/breaking-into-tears-with-microrheology-to-design-custom-eye-drops/