Eye Dynamics and Engineering Network (EDEN) Consortium: Baseline Characteristics of a Randomized Trial in Healthy Adults.

Document Type


Publication Date


Publication Title

Ophthalmology. Glaucoma


PURPOSE: To improve understanding of intraocular pressure (IOP) and its variance, this project identifies systemic and ocular characteristics of healthy eyes of adult volunteers including IOP variation, ocular biometrics, and aqueous humor dynamics (AHD). These data serve as baseline controls for further studies from the Eye Dynamics and Engineering Network (EDEN) Consortium.

DESIGN: Multicenter open-label clinical trial in healthy adults randomized to one week treatment with two approved glaucoma drugs in a crossover design.

PARTICIPANTS: Among 135 healthy participants, 122 participants (55.2 ± 8.8 y; 92 females, 30 males) completed the protocol.

METHODS: Participants from the University of Michigan, Mayo Clinic and University of Nebraska Medical Center underwent measurements of ocular biometrics, AHD, and IOP using four tonometers. IOP was measured during three study visits without glaucoma medications. The PhenX Toolkit survey was used to acquire standardized data on medical history, surgical history, medications, smoking and alcohol exposures, and physical measures.

MAIN OUTCOME MEASURES: The variability of IOP measurements within eyes was assessed as visit-to-visit IOP variation, same day visit IOP variation, and same day visit positional IOP variation. The concordance [or correlation] between eyes also were assessed.

RESULTS: Average positional change of > 4.7 mmHg was detected with a range of 0.5 - 11.0 mmHg. Pearson correlation of IOP between eyes within a visit was 0.87 (95% CI: 0.82, 0.91) for Goldmann applanation tonometry, 0.91 (0.88, 0.94) for Icare rebound tonometry, and 0.91 (0.88, 0.94) for pneumatonometry. There was a 4%-12% asymmetric fluctuation of 3 mmHg or more between eyes between visits using rebound tonometry, 9% with Goldmann applanation tonometry, and 3%-4% by pneumotonometry. The coefficient of variation between visits for the same eye ranged from 11.2%-12.9% for pneumatonometry, from 13.6%-17.4% for rebound tonometry, and 15.8%-16.2% for Goldmann applanation tonometry.

CONCLUSIONS: The current study from the EDEN consortium describes measurement methods and data analyses with emphasis on IOP variability. Future papers will focus on changes in ocular biometrics and AHD with timolol or latanoprost treatment.





First Page


Last Page






PubMed ID