Hydration Status and Ocular Parameters Study
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Relative Dehydration Protocol, Hyperhydration Protocol.
- Who it may be relevant to
- Registry conditions: Hydration Status, Macular Thickness, Ocular Biometry. Basic parameters: 18 years — 65 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
Prospective, Randomized Cross-over Within-subject Study on the Effects of Dehydration and Hyperhydration on Macular Thickness, Corneal Morphology, and Ocular Biometric Parameters Measured by OCT, Pentacam and Optical Biometer
Overview
This study will examine how hydration status (drinking a large amount of water or avoiding water for a short period of time) affects the eye. Healthy adult volunteers will participate in two sessions: one after mild dehydration (no water for 12 hours) and one after drinking 2 liters of water within 4 hours. At each session, detailed eye measurements will be taken, including scans of the retina and optic nerve using optical coherence tomography (OCT), corneal imaging with Pentacam, and eye length measurements with an optical biometer. The results from the two conditions will be compared within the same participants. The main goal is to determine whether hydration influences the thickness of the retina (macula). Secondary goals include assessing changes in the optic nerve, cornea, and other biometric eye parameters. The study involves only non-invasive tests and minimal risk. Findings may help improve understanding of how hydration affects the eye and may be important for clinical practice, such as planning cataract or refractive surgery.
Interventions
- Behavioral Relative Dehydration Protocol
Participants will abstain from water intake for 12 hours prior to the study visit. Food is allowed, but fluid intake is limited to a maximum of 250 ml until 20:00 h on the previous evening. Eye measurements will be performed in the morning (8-10 h). - Behavioral Hyperhydration Protocol
Participants will consume 2 liters of water within 4 hours prior to the study visit. Eye measurements will be performed in the morning (8-10 h).
Primary outcome measures
- Change in macular thickness between dehydration and hyperhydration states [Time frame: Within 1 week (cross-over design with ≥7-day washout period)]
Eligibility criteria
Inclusion criteria
- Healthy adult volunteers aged 18 to 65 years
- Normal ophthalmological findings
- Best corrected visual acuity (BCVA) ≥ 1.0 (decimal)
- Willingness to participate and provide written informed consent
Exclusion criteria
- Known ocular diseases (e.g., glaucoma, keratoconus, retinal pathology)
- History of ocular surgery
- Systemic diseases affecting hydration status (e.g., diabetes mellitus, kidney disease)
- Any condition that, in the investigator's opinion, could interfere with study participation or data quality
- Refusal to participate
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Crossover
- Masking
- Single blind
- Primary purpose
- Basic science
Study locations
Center list to be confirmed — check the primary protocol.
Identifiers
NCT: NCT07177131 · JC092025