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Effect of Binocular Treatment Using a Dichoptic Reading Application in Children With Convergence Insufficiency.

Not Applicable
Not yet recruiting
Conditions
Ophthalmological Disorder
Interventions
Device: Self-education with dichoptic reading on tablet
Procedure: Conventional orthoptic rehabilitation
Registration Number
NCT06465615
Lead Sponsor
University Hospital, Montpellier
Brief Summary

Convergence insufficiency is a common disorder of binocular vision that can appear as early as childhood after visual effort, and is often associated with a variety of symptoms such as eyestrain, headaches, blurred vision and diplopia.

Treatment of symptomatic convergence insufficiency generally involves the intentional and controlled manipulation of a visual target's blur, conjugate and vergence movements around this target, with the aim of normalizing the accommodation and vergence systems and their mutual interactions.

Despite the effectiveness of this treatment, compliance is not optimal, ranging from 24% to 91% in the youngest patients. One of the main challenges is to keep patients focused and interested during the potentially tedious and repetitive periods of over-convergence. In order to stimulate the patient's active participation and stable, sustained attention, a dichoptic reading application on a digital tablet has been developed to provide sustained training in ocular alignment and coordination to reduce symptoms and restore binocular function in patients with symptomatic convergence insufficiency.

Detailed Description

The dichoptic reading application on a digital tablet consists in reading, with red-green anaglyph glasses, a text composed of letters or words presented both binocularly and monocularly (black and red-green, respectively) from downloaded e-books. After centralized randomization, patients will undergo either reference orthoptic rehabilitation (control group) or dichoptic treatment on a digital tablet (experimental group). The control group will receive 12 training sessions (25 minutes twice a week for 6 weeks) as part of their regular treatment in the Ophthalmology Department of the CHU de Montpellier, while the experimental group will perform self-training at home (25 min/day, 5 days a week for 6 weeks). For all participants, an initial visit and two follow-up evaluation visits (visits 2 and 3) will be scheduled 3 and 6 weeks (+ 1 week) after the start of the intervention, and will be carried out by one of the 3 other orthoptists in the Ophthalmology Department of the CHU de Montpellier.

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
26
Inclusion Criteria
  • Patients aged 8 to 17
  • Minimum current schooling: CE2 class
  • Availability of at least one legal guardian to supervise the child's training (strengthening exercises to be performed at home 15 min/day for the control group/ 25 min/day session at home for the experimental group) and complete the patient logbook.
  • Ophthalmological check-up performed within 2 months prior to inclusion
  • Convergence Insufficiency Symptom Survey (CISS) score ≥ 16
  • Convergence punctum proximum ≥ 6 cm
  • Amplitude of fusion in near convergence ≤ 15 prismatic dioptres or less than 2 times the phoria measured in near vision (Sheard's criterion).
  • Best corrected distance and near visual acuity ≥ 20/25 (=8/10) and wearing appropriate refractive correction (glasses or contact lenses) for at least 2 weeks prior to study inclusion.
  • See letters/words and be able to read 3 complete sentences on a predefined text presented dichoptically on the tablet with anaglyph glasses
  • Availability of the patient to complete the training protocol over 6 weeks (or a maximum of 9 weeks in the event of temporary interruption of treatment).
Exclusion Criteria
  • Binocular vergence dysfunctions such as constant strabismus
  • Prism (unless removed ≥ 2 weeks prior to inclusion)
  • History of recent orthoptic rehabilitation (< 6 months)
  • History of intraocular or refractive surgery
  • Current amblyopia treatment or treated amblyopia (isoacuity) < 6 months
  • Best corrected visual acuity of the worse eye < 8/10
  • Medication that may interfere with binocular vision and/or accommodation
  • Accommodation paralysis
  • Ocular comorbidity likely to reduce visual acuity
  • History of vestibular migraines, vestibular disorders
  • History of ocular or systemic disease, infections/congenital malformations
  • Neurological history: stroke, head trauma, tumors, epilepsy or neurodegenerative disorders
  • Specific learning disability
  • Developmental delay (global, language, learning) likely to interfere with treatment or evaluation.
  • Failure to obtain written informed consent after a period of reflection
  • Not being affiliated to a French social security scheme or benefiting from such a scheme
  • Pregnant or breast-feeding

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Experimental groupSelf-education with dichoptic reading on tabletself-rehabilitation at home. Intervention 25 min/day, 5 days a week for 6 weeks at home (weekly load of 125 minutes), on a dichoptic reading application on a loaned digital tablet, wearing anaglyph glasses provided and patient's optical correction (if applicable).
Control groupConventional orthoptic rehabilitationThe control group will receive conventional treatment consisting of 12 sessions of 25 minutes each over 6 weeks of rehabilitation with an orthoptist in the ophthalmology department of Montpellier University Hospital.
Primary Outcome Measures
NameTimeMethod
Evolution of symptoms at the end of the interventionT0 and T6 weeks

Evolution of symptoms assessed via the Convergence Insufficiency Symptom Survey (CISS) score, version 15, measured before and 6 weeks after the start of the intervention in children with convergence insufficiency.

Evolution of symptoms halfway through the interventionT0 and T3 weeks

Evolution of symptoms (decrease in Convergence Insufficiency Symptom Survey (CISS) score measured 3 weeks after the start of binocular treatment)

Secondary Outcome Measures
NameTimeMethod
Adverse eventsT3 weeks ands T6 weeks

Collection of adverse events self-reported by the patient and collected by the medical team during assessment visits.

Evolution of the punctum proximum of convergence (PPC)T0 and T3 weeks and T0 and T6 weeks

This test defines the closest point of fixation to the patient on which the 2 eyes can converge and see simply. It is measured using the Astron ACR/21 international accommodative rule.

Evolution of reading speedT0 and T3 weeks ans T0 and T6 weeks

reading speed assessed by the Minnesota Low Vision Reading Test (MNREAD) in seconds.

Changes in quality of lifeT0 and T3 weeks ans T0 and T6 weeks

Quality of life measured with the Pediatric Quality of Life Inventory (PedsQL)

Prevalence of patients with "Complete Response", "Partial Response" and "NonrespondersT3 weeks and T6 weeks

Prevalence of patients with "Complete Response", "Partial Response" and "Nonresponders", defined as follows:

Complete response :

* ISSC score \<16

* AND normal convergence punctum proximum (i.e. less than 6 cm)

* AND normal near convergence fusion amplitude (i.e. greater than 15Δ and satisfying Sheard's criterion).

Partial response:

* CISS score \<16 or 10-point decrease in CISS

* AND :

* Normal convergence punctum proximum

* OR improvement in convergence proximal punctum of more than 4 cm

* OR normal near convergence fusion amplitude

* OR increase in near convergence fusion amplitude by more than 10Δ. Non-responders: Patients not meeting the criteria for success or improvement.

Adherence to self-trainingT3 weeks and T6 weeks

Adherence to self-training evaluated in a patient logbook: training time completed vs. training time planned.

Evolution of stereoacuityT0 and T3 weeks and T0 and T6 weeks

The McGill clinical stereo test (McGill University) evaluates relief vision (threshold expressed in arcseconds) through a digital tablet with red-green anaglyph glasses.

Treatment complianceT3 weeks and T6 weeks

For the experimental group, compliance is measured using a percentage of training sessions completed, obtained from automatic recording by the tablet software and the patient diary, in which the date and duration (seconds) of each training session are recorded. For the control group, compliance is measured using a percentage combining the number of training sessions performed (collected by the orthoptist) and home exercises (self-reported by the patient), with dates and durations recorded in a patient logbook.

Visual comfort when using the dichoptic reading applicationT3 weeks and T6 weeks

Measurement of visual comfort when using the dichoptic reading application with the modified Convergence Insufficiency Symptom Survey score.The modified Convergence Insufficiency Symptom Survey score ranges from 0 to 60. Higher scores mean a worse outcome, indicating a high presence of symptoms.

Normalization of punctum proximum of convergence (PPC)T0 and T3 weeks ans T0 and T6 weeks

A normal convergence punctum proximum is defined as less than 6 cm.

Interocular suppression measured with the Dichoptic Contrast Ordering Test (DICOT)T0 and T3 weeks ans T0 and T6 weeks

Interocular suppression measured with the Dichoptic Contrast Ordering Test (DICOT)

Level of certainty of recognition of the patient randomization arm for the evaluating orthoptistT3 weeks and T6 weeks

Likert scale assessing the evaluator's level of certainty regarding recognition of the patient's allocation to the experimental arm. The modified Convergence Insufficiency Symptom Survey score ranges from 0 to 4. higher scores mean a better outcome, indicating a low level of certainty of recognition of patient randomization arm.

Normalization of fusion amplitude in near convergenceT0 and T3 weeks ans T0 and T6 weeks

A fusion amplitude in near-normal convergence is defined as greater than 15Δ and satisfying Sheard's criterion.

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