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A New Parameter for the Assessment of Distance Visual Capacity: the Critical Visual Acuity (CVA)

NCT04632901 · Status: ACTIVE_NOT_RECRUITING · Type: OBSERVATIONAL · Enrollment: 300

Last updated 2025-07-11

No results posted yet for this study

Summary

The conventional examination of the visual acuity (VA) does not take into account the patient's reading speed. However, the consideration of the speed for the recognition of the VA charts' symbols leads to the more accurate and comprehensive assessment of the visual capacity.

Therefore, primary objective of this study is to develop and validate a new parameter for the more comprehensive evaluation of visual capacity: the critical visual acuity (CVA). CVA takes into account the speed of recognition of the symbols of the distance visual charts.

Conditions

  • Visual Acuity

Interventions

DIAGNOSTIC_TEST

VA assessment

The VA of all participants will be evaluated by counting the smallest line that can be read within a time duration greater than or equal to the average reading time of the larger lines minus 2.58 times the SD of the reading time of these lines. In clinical practice, the VA is the common parameter of VA adding a tolerant time limit to clearly determine the end of the test.

DIAGNOSTIC_TEST

CVA assessment

The CVA of all participants will be evaluated by counting the smallest line that can be read within a time duration greater than or equal to the average reading time of the larger lines minus 1.96 times the SD of the reading time of these lines. In clinical practice, the CVA is the minimum VA that can be read in maximal speed.

Sponsors & Collaborators

  • Democritus University of Thrace

    lead OTHER

Principal Investigators

  • Georgios Labiris, MD, PhD · Department of Ophthalmology, University Hospital of Alexandroupolis, Alexandroupolis, Greece

Eligibility

Min Age
18 Years
Max Age
75 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2020-09-20
Primary Completion
2025-07-20
Completion
2025-12-20

Countries

  • Greece

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT04632901 on ClinicalTrials.gov