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Determining the Efficacy of Full-time Occlusion Therapy in Severe Amblyopia at Different Ages

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02113709
Recruitment Status : Unknown
Verified April 2014 by Dr. Sameera Irfan, Mughal Eye Trust Hospital.
Recruitment status was:  Active, not recruiting
First Posted : April 15, 2014
Last Update Posted : April 15, 2014
Information provided by (Responsible Party):
Dr. Sameera Irfan, Mughal Eye Trust Hospital

Brief Summary:

Objective: To find out how much visual improvement is possible in severe amblyopia using full-time occlusion therapy with an eye patch and to see if improvement is influenced by the patient's age.

Methods: An interventional clinical trial of 115 consecutive cases with unilateral, severe amblyopia was conducted at a tertiary referral center from Jan 2010 to Oct 2012. Patients were divided into three age groups: 3-7 years (n= 38), 8-12 years (n=41), 13-35 years (n=36). After a complete ophthalmological examination by a single ophthalmologist, cases with organic visual loss were excluded; cases with previous part-time occlusion therapy that had failed were included in the study. Patients were given optimal refractive correction for a month, followed by full-time occlusion therapy along with near visual activities for 3-4 hours/day. The therapy was continued until maximum visual recovery was achieved (6/6 Snellen's). Therapy was gradually reduced and stopped. Patients were followed-up regularly for the next 18 months.

Condition or disease Intervention/treatment Phase
Amblyopia Strabismus Device: Occlusion therapy by Eye Patch Device: Occlusion therapy Not Applicable

Detailed Description:
Amblyopia, ('blunt vision' in Ancient Greek), also known as lazy eye, is a visual deficiency in an eye that is otherwise physically normal, or that is greater than would be expected from any structural abnormalities of the eye. There are unsubstantiated beliefs that it is more difficult to treat amblyopia in older age groups, that children that have already received failed amblyopia therapy do not respond to treatment and that full-time occlusion therapy may result in occlusion (disuse) amblyopia of the good eye. The aim of this study was to assess whether these beliefs are true. Materials and methods This was a prospective, interventional clinical trial of 115 consecutive cases with unilateral, severe amblyopia conducted at a tertiary referral center in Lahore, Pakistan, from January 2010 to October 2012. Eligibility criteria included an age of over three years, visual acuity in the amblyopic eye from 6/60 Snellen's or even counting fingers only, visual acuity in the sound eye of 6/6. A complete ophthalmic examination was performed by only one ophthalmologist (SI). This included examining the fixation pattern of both eyes, presence or absence of a phoria or a tropia by a cover-uncover test, fundus examination and color vision using Ishihara color plates. Any case with an organic cause for visual loss was excluded from the study after a thorough ophthalmological examination. Assessment of visual acuity of either eye for both near and distance acuity (Snellen's and ETDRS charts) refraction and Best Corrected Visual Acuity (BCVA) was performed by a trained optician who was masked to the study and patient's demographics.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 115 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Determining the Efficacy of Full-time Occlusion Therapy in Severe Amblyopia at All Ages
Study Start Date : January 2010
Actual Primary Completion Date : October 2012
Estimated Study Completion Date : June 2014

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Amblyopia

Arm Intervention/treatment
Experimental: Visual improvement
To see how efficiently visual improvement occurs by Full-time Occlusion therapy with an eye patch in severe amblyopia.
Device: Occlusion therapy by Eye Patch
The good eye was occluded by a stick-on eye patch to stimulate the amblyopic eye and its neural connections to learn to see again.

Device: Occlusion therapy
To see how much improvement in visual acuity occurs by full-time occlusion therapy.
Other Name: eye patch (commercially pre-packed)

Primary Outcome Measures :
  1. Visual Acuity improvement [ Time Frame: 3 months ]
    Full-time occlusion therapy of good eye was performed for 2-3 months while closely monitoring the vision of both the good and the amblyopic eye. Vision was assessed by EDTRS Charts as well as Snellen's Chart.

Secondary Outcome Measures :
  1. improvement in stereopsis [ Time Frame: 1 year ]
    as equal visual acuity is attained by both eyes, the stereopsis also improves. It was assessed by satandardized TNO plates with the patient wearing polarized glasses over their own corrective spectacles.

Other Outcome Measures:
  1. Does the patched good eye develop occlusion amblyopia [ Time Frame: 3 months ]
    The vision of patched good eye was meticulously monitored to note the development of occlusion amblyopia

Information from the National Library of Medicine

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Ages Eligible for Study:   3 Years and older   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • a visual acuity of 6/60 or 0.1-0.2 ETDRS in one eye and 6/6 or 1.0 ETDRS in the good eye
  • strabismic amblyopia
  • patients of any age were included.

Exclusion Criteria:

  • structural damage to the eye (organic amblyopia)
  • ametropic amblyopia

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02113709

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Mughal Eye Trust Hospital
Lahore, Punjab, Pakistan, 54770
Sponsors and Collaborators
Mughal Eye Trust Hospital
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Principal Investigator: Sameera Irfan, FRCS Mughal Eye Trust Hospital, Lahore, Pakistan

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Responsible Party: Dr. Sameera Irfan, Consultant Ophthalmologist, Mughal Eye Trust Hospital Identifier: NCT02113709     History of Changes
Other Study ID Numbers: SIrfanMEHT
First Posted: April 15, 2014    Key Record Dates
Last Update Posted: April 15, 2014
Last Verified: April 2014
Keywords provided by Dr. Sameera Irfan, Mughal Eye Trust Hospital:
Occlusion therapy
Visual improvement
Additional relevant MeSH terms:
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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