Characteristics of the Vergence Responses of Binocularly Normal Subjects After a Vision Therapy Protocol

Universitat Politècnica de Catalunya

Status: Unknown

Conditions: Binocular Vision Disorder; Vision Therapy; Vision Disorders; Eye; Movement Disorder (Binocular)

Treatments: Other: Experimental: Classical Vision Therapy Treatment; Other: Control: Eye Movement Therapy Treatment

Study type: Interventional

Funder types: Other

Identifiers

NCT05208658

Vergence VT Protocol

Details and patient eligibility

About

A vision therapy protocol for vergence ability is mentioned. The purpose of this study is to evaluate objectively the change in the vergence responses of binocular and accommodative normal subjects after performing a classic vision therapy protocol. This study is an interventional, cross-over, and randomized study.

Full description

After the first evaluation, subjects will be classified in the Experimental Group (EG) or Control Group (CG) randomly. There will be 18 subjects in each group. A classic vision therapy protocol for fusional vergence will be performed in the EG and the CG will be doing a placebo therapy, based on studies done before.

The EG will do weekly office-based therapy of 45 minutes during 12 weeks and the CG will do weekly office-based placebo therapy of 15 minutes during 12 weeks. This placebo therapy will consist of smooth-pursuit and discrimination exercises that do not influence vergence response. The office-based done by the EG consists of a vergence therapy and its protocol will follow Scheiman's indications protocol. This vision therapy will train both positive and negative fusional vergence amplitudes in the same proportion.

A pre-evaluation, a during evaluation, and a post-evaluation will be done at weeks 1, 6, and 12 respectively to all subjects. After the post-evaluation week, the CG will do 12 weeks more of office-based therapy but, this group will do the same conventional vergence protocol as EG. The CG will be evaluated at week 18, and finally, at week 24.

During the evaluations, the vergence eye movements will be measured during the positive and negative fusional vergence tests. The break and the recovery points will be evaluated to all the subjects with three different methods performed in a randomized order: (1) objective computer-based test in the haploscopic system, (2) prism bar, and (3) phoropter rotary prisms. All these tests will be performed at 40 cm with a classic central visual target.

This study aims to evaluate objectively the change in the vergence responses of binocular and accommodative normal subjects after performing a classic vision therapy protocol.

Enrollment: 34 estimated patients

Sex: All

Ages: 20 to 30 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Normal binocular and accommodative subjects will participate in the study. All subjects have to fulfill the inclusion criteria. All evaluations will consist of the following objective and subjective optometric tests, which will be executed for all participants.

1. Monocular and binocular VA at near and distance with their habitual correction
2. Refractive error measured with the Grand Seiko WAM-5500 Autorefractor
3. Cover Test at near (40 cm)
4. Near Point of Accommodation
5. Near Point of Convergence
6. Vergence Facility Test at near (40 cm)
7. Monocular and binocular Accommodation Facility Test at near (40 cm)
8. Negative and Positive Relative Accommodation Test (ARN and ARP)
9. Random Dot 2 Stereo acuity Test
10. CISS questionnaire
11. Fusional Vergence Amplitude using both subjective and objective methods

Exclusion Criteria:

• having eye surgery
• having an eye pathology
• having a binocular or an accommodative disorder
• using orto-K lenses

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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34 participants in 2 patient groups, including a placebo group

Classical Vision Therapy Treatment: vision therapy exercises for fusional vergence abilities

Experimental group

Description:

The Experimental Group (EG) it consist in a Classical Vision Therapy Treatment. This group will do weekly office-based therapy of 45 minutes of visual exercises during 12 weeks. The office-based done by the EG consists of a vergence therapy and its protocol will follow Scheiman's Protocol and Indications. The exercises do not tough the eye or use drugs. They are just visual training exercises that improve fusional convergence and divergence response.

Treatment:

Other: Experimental: Classical Vision Therapy Treatment

Eye Movement Therapy Treatment: vision therapy placebo exercises not improve fusional vergence

Placebo Comparator group

Description:

The Control Group or Placebo Group consist in a Control: Eye Movement Therapy Treatment. This group will do weekly office-based placebo therapy of 15 minutes during 12 weeks of visual exercises. This placebo therapy will consist of smooth-pursuit and discrimination exercises that do not influence vergence response. The exercises do not tough the eye nor use drugs. They are just visual training exercises that do not improve fusional vergence response as they improve smooth-pursuit eye movements.

Treatment:

Other: Control: Eye Movement Therapy Treatment

Other: Experimental: Classical Vision Therapy Treatment