The Effectiveness of Visual Training in Convergence Insufficiency Patients

NCT ID: NCT05603962

Last Updated: 2024-12-03

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 12 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-03-06
• Study Completion Date: 2024-06-26

Brief Summary

Convergence insufficiency (CI) is one of the most common binocular vision disorders. The prevalence of CI ranges from 3% to 6% in school-aged children. CI symptoms include visual fatigue, headache, blurred vision, and diplopia and could be caused while using near-distance viewing. These symptoms might become more severe with increasing need to perform near-distance tasks. Long-term visual symptoms could result in a negative impact on learning behaviors and work performance in patients. Nowadays, visual training is the main type of management for CI patients clinically; however, the existing training protocol required patients to make several visits to the clinic for visual training, which might increase the burden for patients and result in higher failures in training. Therefore, this study will use a simple training method by utilizing prisms for CI patients to train at home, then compare visual symptoms and binocular vision after the training. In stage I of this study, investigators will recruit 60 symptomatic CI participants aged 9 to 30 years old to do a 6-week visual training with the prisms (15 min/time, 3 times/week). The post-training outcomes will be collected at week 4 and week 6. In stage II, all of the participants will be randomly divided into the "stop training group" and the "continue training group." The participants in the "continue training group" will have the same 6-week prism training and in the "stop training group" will stop all the prism training during this period. The final post-training outcomes of all the participants will be collected again at week 12. In this study, investigators will investigate the effectiveness of the prisms training for 6 weeks and for 12 weeks on visual symptoms and binocular vision in CI patients, and evaluate whether the training effect will be affected by stopping training after 6 weeks.

Conditions

Convergence Insufficiency

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: HEALTH_SERVICES_RESEARCH
• Blinding Strategy: NONE

Study Groups

Stop training group

Home-base prism training during week 1-6 --\> then stop training during week 7-12 --\> endpoint data collected at week 12

Group Type: ACTIVE_COMPARATOR

Visual training

Intervention Type: BEHAVIORAL

Visual training is the main type of management for CI patients clinically; however, the existing training protocol required patients to make several visits to the clinic for visual training, which might increase the burden for patients and result in higher failures in training. Therefore, this study will use a simple training method by utilizing prisms for CI patients to train at home, then compare visual symptoms and binocular vision after the training.

Continune training group

Home-base prism training during week 1-12 --\> endpoint data collected at week 12

Group Type: EXPERIMENTAL

Visual training

Intervention Type: BEHAVIORAL

Visual training is the main type of management for CI patients clinically; however, the existing training protocol required patients to make several visits to the clinic for visual training, which might increase the burden for patients and result in higher failures in training. Therefore, this study will use a simple training method by utilizing prisms for CI patients to train at home, then compare visual symptoms and binocular vision after the training.

Interventions

Visual training

Visual training is the main type of management for CI patients clinically; however, the existing training protocol required patients to make several visits to the clinic for visual training, which might increase the burden for patients and result in higher failures in training. Therefore, this study will use a simple training method by utilizing prisms for CI patients to train at home, then compare visual symptoms and binocular vision after the training.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

1. The overall score of CI symptom survey ≥ 16 (9-18 years old) or ≥ 21 (19-30 years old)

2. The break point of near point of convergence (NPC) ≥ 6 cm

3. Exophoria at near distances be at least 4∆ higher than at far distances

4. Near positive fusional vergence (PFV) ≤ 15∆ or failing Sheard's criterion at near.

Exclusion Criteria

1. The best corrected visual acuity (BCVA) of < 20/25 in each eye at far and near distances

2. Amblyopia patients or the difference of BCVA between the two eyes ≥ 2 lines

3. Constant strabismus patients

4. History of strabismus surgery or refractive surgery

5. Systemic diseases that would affect binocular vision

6. Acquired brain injury or neurological disorder.

• Minimum Eligible Age: 9 Years
• Maximum Eligible Age: 30 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Taiwan University Hospital

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Tzu-Hsun Tsai, PhD

Role: PRINCIPAL_INVESTIGATOR

National Taiwan University Hospital

Locations

National Taiwan University Hospital

Taipei County, , Taiwan

Countries

Taiwan

Other Identifiers

202207058RINB

Identifier Type: -

Identifier Source: org_study_id