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

N/ANot Yet RecruitingNCT06465615

University Hospital, Montpellier26 enrolled

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Interventions

Self-education with dichoptic reading on tabletDEVICE

Intervention 25 min/day, 5 days a week for 6 weeks at home (125-minute weekly load), under the supervision of a parent, on a dichoptic reading application on a loaned digital tablet, wearing anaglyph glasses provided and the patient's optical correction (if applicable). During the first half of treatment (first 3 weeks), dichoptic separation takes place at the word level, and during the second half of treatment (last 3 weeks), it takes place at the individual letter level to promote precise eye alignment. This shift from dichoptic separation at word level to letter level increases the difficulty of the task. The text is freely chosen by the child and parent from a bank of age-appropriate books.

Conventional orthoptic rehabilitationPROCEDURE

Conventional orthoptic rehabilitation consisting of 12 x 25-minute sessions twice a week over 6 weeks, carried out with an orthoptist from Montpellier University Hospital, combined with reinforcement exercises to be carried out at home for 15 minutes a day under parental supervision, 5 days a week (125-minute weekly load). This is the standard orthoptic treatment offered in France to patients with symptomatic convergence insufficiency, according to orthoptic procedures (10-15 sessions of the order of 20-25 minutes and 10-15 minutes of daily reinforcement exercises at home).

Eligibility

Sex: ALLMin age: 8 YearsMax age: 17 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Evolution of symptoms at the end of the intervention

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.

Time frame: T0 and T6 weeks

Evolution of symptoms halfway through the intervention

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

Time frame: T0 and T3 weeks

Secondary Outcomes

Evolution of the punctum proximum of convergence (PPC)

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.

Time frame: T0 and T3 weeks and T0 and T6 weeks

Evolution of stereoacuity

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

Time frame: T0 and T3 weeks and T0 and T6 weeks

Normalization of fusion amplitude in near convergence

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