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Vision Screening for the Detection of Amblyopia

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified September 2011 by Mladen Busic, General Hospital Sveti Duh.
Recruitment status was:  Enrolling by invitation
Information provided by (Responsible Party):
Mladen Busic, General Hospital Sveti Duh Identifier:
First received: August 31, 2011
Last updated: September 6, 2011
Last verified: September 2011

INTRODUCTION. Amblyopia is defined as the loss of visual acuity (VA) in one or both eyes, without any obvious structural or pathological anomalies. Amblyopic eye should be able to regain some VA if treatment is initiated before the age of seven. It is the leading cause of monocular blindness in the 20- to 70-year olds with prevalence 2-5%. Amblyopia is mainly monocular, hence children are general asymptomatic. VA testing is the only reliable method of detecting amblyopia, and the fourth year of life is considered best for vision screening programs.

AIM: The purpose of the study is to reduce the preventable vision loss. The main goal of the study is to evidence the problem of amblyopia in Zagreb and to release a model for formal, government directed vision-screening program as a Croatian public health policy.

HYPOTHESIS. In Croatia, the prevalence and actual effect of amblyopia and amblyogenic factors, along with treatment efficacy is impossible to quantify, since no population-based studies have been performed regarding this issue. In addition, national screening of preschool children does not exist, while the school-entry screening is prescribed by law. The object of the study is to determine the prevalence of amblyopia in a 4-4.5 year old children of The Town of Zagreb, the efficacy of screening and effectiveness of treatment on reducing amblyopia prevalence. The primary hypothesis is defined: screening of visual acuity monocularly at distance and near in 4-4.5 year old children in Zagreb is effective in detecting amblyopia.

PATIENTS AND METHODS: Monocular vision of about 7000 children/ year aged 4-4.5 for whom both parents gave consent is to be tested with Lea chart at near (40cm) and distance (3m) in the kindergartens of The Town of Zagreb. The criterion for referral to complete ophthalmological examination is VA <0.8.

Condition Intervention
Amblyopia Refractive Errors Anisometropia Strabismus Ptosis Other: Amblyopia screening

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Screening
Official Title: Vision Screening of the Four Year Old Children for the Detection of Amblyopia in The Town of Zagreb

Resource links provided by NLM:

Further study details as provided by Mladen Busic, General Hospital Sveti Duh:

Primary Outcome Measures:
  • prevalence of amblyopia [ Time Frame: 3 years ]
    proportion of children with amblyopia in a total population of children screened

Estimated Enrollment: 7000
Study Start Date: September 2011
Estimated Study Completion Date: September 2014
Estimated Primary Completion Date: September 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Amblyopia screening Other: Amblyopia screening
Monocular vision testing at near (40cm) and distance (3m)


Ages Eligible for Study:   48 Months to 54 Months   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • children in the kindergartens of The Town of Zagreb aged 4-4.5 for whom both parents gave written informed consent

Exclusion Criteria:

  • children younger than 4 years and children older than 4.5 years
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Please refer to this study by its identifier: NCT01430247

University Eye Clinic, University Hospital "Sveti Duh"
Zagreb, Croatia, 10 000
Sponsors and Collaborators
Mladen Busic
Principal Investigator: Mladen Bušić University Eye Clinic, University Hospital "Sveti Duh", Zagreb, Croatia
  More Information

Responsible Party: Mladen Busic, Asst. prof., M.D., PhD, General Hospital Sveti Duh Identifier: NCT01430247     History of Changes
Other Study ID Numbers: 30082011/2011
Study First Received: August 31, 2011
Last Updated: September 6, 2011

Keywords provided by Mladen Busic, General Hospital Sveti Duh:
amblyogenic factors
preschool children
visual acuity

Additional relevant MeSH terms:
Refractive Errors
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vision Disorders
Sensation Disorders
Neurologic Manifestations
Eye Diseases
Signs and Symptoms
Ocular Motility Disorders
Cranial Nerve Diseases processed this record on August 16, 2017