This study evaluates the immediate effects of two types of artificial tear formulations on corneal aberrations in a healthy population. The interventions include a lipid-based formulation containing mineral oil and hydroxypropyl guar, and a non-lipid formulation containing hydroxypropyl guar alone. Participants will receive a single instillation of each formulation in separate eyes, with measurements of corneal aberrations taken before and 15 minutes after instillation. The study aims to compare the optical changes induced by these formulations and assess their impact on the ocular surface quality.

This study explores the immediate effects of two types of artificial tear formulations on corneal aberrations in healthy individuals. The primary aim is to evaluate how a lipid-based formulation containing mineral oil and hydroxypropyl guar and a non-lipid formulation containing hydroxypropyl guar alone influence optical quality shortly after instillation. The results of this research will contribute to a better understanding of how these formulations interact with the ocular surface to enhance or alter corneal optical properties.

The study will involve healthy participants aged 18 to 35 years, with no prior history of ocular surface disease, refractive surgery, or contact lens use. All participants will undergo a baseline assessment of corneal aberrations before any intervention. Each individual will then receive a single drop of the lipid-based formulation in one eye and the non-lipid formulation in the other eye. This approach allows for direct comparison between the two interventions within the same participant. Measurements of corneal aberrations will be taken 15 minutes after instillation to capture the immediate effects of each formulation on optical quality.

The study is designed as a randomized, participant-masked clinical trial to ensure unbiased results. By measuring higher-order aberrations (HOAs) with wavefront aberrometry, the research will assess how these artificial tears affect the ocular surface's optical properties. This will provide valuable insights into their potential to stabilize the tear film and enhance visual performance. The trial follows ethical guidelines and has been approved by the appropriate Institutional Review Board.

This research is important for advancing knowledge about artificial tear formulations and their role in managing ocular surface conditions. Although both formulations are commonly used in clinical practice, their specific effects on corneal aberrations immediately after application have not been thoroughly studied in a healthy population. The findings from this study will help inform healthcare providers and patients about the optical benefits and limitations of these widely used artificial tear formulations.

Inclusion Criteria:

Healthy individuals aged 18 to 35 years. No prior history of ocular surface disease, refractive surgery, or contact lens wear.

Corrected visual acuity of 20/20 or better. Ability to provide informed consent. Willingness to comply with study procedures, including instillation of artificial tears and follow-up measurements.

Exclusion Criteria:

History of any ocular surgery or trauma within the past six months. Use of any systemic or topical medications that may affect ocular surface stability or tear film.

Any active or chronic ocular infection, inflammation, or other pathology. Known hypersensitivity or allergy to any components of the artificial tears. Pregnancy or breastfeeding. Participation in another clinical trial within the last 30 days.

The individual participant data (IPD) will not be shared due to privacy and confidentiality concerns. The data collected in this study will be used solely for the purposes outlined in the research protocol and will remain confidential according to applicable data protection regulations. Aggregate data and study results will be shared in peer-reviewed publications and presentations, but individual-level data will not be made publicly available.

Participants, investigators, and outcomes assessors will not know which formulation is being administered. Identical containers and consistent procedures will ensure masking.