Date of Award

Summer 8-29-2019

Degree Type


Degree Name

Master of Science in Vision Science

Committee Chair

Amiee Ho, OD

Second Advisor

John Hayes, PhD

Third Advisor

Patrick Caroline, COT


Purpose: To identify the effects of increased water intake on dry eye signs and symptoms and their association to retinal vessel diameter changes in healthy optometry students using the OCT-A.

Methods: Candidates were screened for their hydration status and only dehydrated candidates (those who drink less than what is required for their weight) were eligible to participate. All individuals self-reported having no systemic conditions or ocular conditions linked with dry eyes. Thirty-six qualified subjects were evaluated for dry eye signs by assessing tear break-up time, tear volume, lipid layer thickness, blink rate, and Meibomian gland health. The Standardized Patient Evaluation of Eye Dryness (SPEED) Questionnaire was used to screen subjects for severity of dryness as well as evaluate dry eye symptoms during the study. OCT-A was used to evaluate blood vessel changes pre- and post-water consumption. Qualifying subjects were asked to drink a specified amount of water within 24 hours. Signs and symptoms of dry eye were re-evaluated the next day.

Results: ANCOVA analysis compared each subject’s post-treatment results to their pre-treatment (baseline) results. There was a significant difference between the control group and the experimental group for the SPEED score (p < 0.05). There was no significant difference for tear break-up time, tear volume, lipid layer thickness, blink rate and Meibomian gland health between the control group and experimental group. Retinal vessel diameter changes were compared between the two groups using a simple scatterplot. Retinal vessel diameter changes showed mixed results for water intake and retinal diameter correlations. Overall, there was no significance in vessel diameters between groups.

Conclusions: Increased water intake does not improve signs of dry eye. However, subjects in the experimental group of this study experienced improved symptoms after increased water intake. This effect must be further investigated. The study also showed inconclusive data on the effect of retinal vessel diameter changes after increased water intake. This also requires further investigation.