NCT07177131

Hydration Status and Ocular Parameters Study

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

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 60 (estimated)
• Sponsor: Ante Kreso · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Accepted

Summary

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.

Conditions

• Hydration Status
• Macular Thickness
• Ocular Biometry

Interventions

Type	Name	Description
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).

Timeline

• Start date: 2025-09-25
• Primary completion: 2025-11-01
• Completion: 2025-12-01
• First posted: 2025-09-16
• Last updated: 2025-09-22