Related Experiment Video
Updated: Mar 22, 2026

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential
Published on: May 25, 2020
Value of Routine Eye Examinations in Asymptomatic Patients
Elizabeth L Irving1, Joel D Harris, Carolyn M Machan
1*PhD †OD ‡MSc §BA School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada (all authors).
Purpose:
To determine if routine eye examinations in asymptomatic patients result in spectacle prescription change, new critical diagnosis, or new management of existing conditions. We also investigate whether age and time between assessments (assessment interval) impact detection rates.
Methods:
The Waterloo Eye Study (WatES) database was created from a retrospective file review of 6397 patients seen at the University of Waterloo Optometry Clinic. Significant changes since the previous assessment (significant change) were defined as a change in spectacle prescription, presence of a new critical diagnosis, or a new management. Significant change, assessment interval, and age were extracted from the database for all asymptomatic patients presenting for a routine eye examination. The frequency of patients with significant change and the median assessment interval were determined for different age groups.
Results:
Of 2656 asymptomatic patients, 1078 (41%) patients had spectacle prescription changes, 434 (16%) patients had new critical diagnoses, 809 (31%) patients had new managements, and 1535 (58%) patients had at least one of these (significant change). Median assessment intervals were 2.9 and 2.8 years for age groups 40 to <65 years and 20 to <40 years, respectively, approximately 1.5 years for patients 7 to <20, and between 1 and 1.5 years for patients <7 or >64. Controlling for assessment interval and sex, increasing age was associated with having a significant change (OR = 1.03, 95% CI 1.029-1.037). Similarly, controlling for age and sex, increased assessment interval was associated with having a significant change (OR = 1.06, 95% CI 1.02-1.11).
Conclusions:
In asymptomatic patients, comprehensive routine optometric eye examinations detect a significant number of new eye conditions and/or result in management changes. The number detected increases with age and assessment interval.
Related Concept Videos
Accessory Structures of the Eye
Glaucoma: Overview
Open Angle Glaucoma: Treatment
Drugs such as carbonic anhydrase inhibitors, α2- and...
Angle Closure Glaucoma: Treatment
Assessment of the Mouth
Mouth Inspection
The inspection begins with visually examining the mouth for symmetry, color, and size.

