A Comparative Study of the Efficacy of Myopia Control Lenses With Different Mechanisms on Controlling Myopia Progression in Patients With Intermittent Exotropia

The goal of this clinical trial is to compare the efficacy of myopia control lenses with different working principles in patients with intermittent exotropia aged 6 to 12 years. The main questions it aims to answer are:

Are there any differences in the clinical outcomes of DIMS and DOT glasses between children with intermittent exotropia and those with simple myopia (without intermittent exotropia)? Do DIMS and DOT glasses differ in their myopia control efficacy among children with intermittent exotropia? Does wearing DIMS or DOT glasses affect the binocular visual function of children with intermittent exotropia?

Study Overview

• Status: Not yet recruiting
• Conditions: Myopia; Intermittent Exotropia
• Intervention / Treatment: Device: DIMS glasses; Device: DOT glasses

Detailed Description

Intermittent exotropia (IXT) is a common ophthalmic disorder. It is clinically characterized by outward deviation of the eye position when patients fixate on distant targets, feel fatigued, or become inattentive. This condition impairs stereoscopic vision and visual quality, and may further deteriorate binocular fusion function, thereby considerably interfering with daily activities. Epidemiological data indicate that the prevalence of intermittent exotropia is approximately 4.7% in Asian populations. In China, it accounts for 75.64% of all strabismus cases, ranking first among all types of strabismus. Notably, more than 50% of children with intermittent exotropia are affected by myopia. Several studies suggest that these two conditions may share common pathogenetic mechanisms and present as comorbid disorders.

Currently, the mainstream designs of myopia control glasses are based on two core principles: peripheral defocus control and diffusion optics technology. Peripheral defocus glasses induce myopic defocus by refracting peripheral light to focus in front of or on the retina, which inhibits excessive axial elongation. Lenses adopting diffusion optics technology reduce the contrast of peripheral retinal images via microstructural design, so as to slow myopia progression. A number of clinical trials have verified the favorable efficacy of both lens types for myopia control in general children.

Nevertheless, systematic controlled studies comparing the myopia control effects between the two types of glasses in myopic children with concomitant intermittent exotropia remain scarce. Therefore, this comparative study focusing on this specific population possesses important clinical value and can also provide theoretical evidence for the formulation of individualized myopia management strategies.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Xiaoning Yu, M.D.; Phone Number: +86 13738170635; Email: yxnzju@zju.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Participants aged 6 to 12 years (6 ≤ age ≤ 12 years). Written informed consent from legal guardians is mandatory.

2. Patients with basic-type intermittent exotropia (IXT) meeting all the following criteria:

   1. Intermittent or constant exotropia at the distance of 6 meters, and intermittent exotropia or esophoria at the near distance of 33 centimeters;
   2. Distance exodeviation ≥ 10 prism diopters (PD) measured via the prism and alternate cover test (PACT);
   3. The difference between near and distance deviation ≤ 10 PD.
3. Based on cycloplegic spherical equivalent (SE), the myopic refractive error of both eyes ranges from -6.0 D to -0.5 D.
4. The logMAR value of monocular distance best-corrected visual acuity (BCVA) measured by the ETDRS chart is ≤ 0.2, and no amblyopia is present.
5. Parents and children are willing to participate in this clinical trial and can complete the entire study protocol.
6. Children have healthy eyes without organic ocular diseases.

Exclusion Criteria:

1. Participants who have worn myopia control glasses or received other myopia interventions, including low-concentration atropine and phototherapy instruments, within the past 6 months (excluding DIMS and DOT glasses).
2. Those with severe systemic diseases or cognitive impairment that hinders follow-up attendance and clinical examinations.

4. Subjects with astigmatism of ≥ 2 diopters (D) in either eye after cycloplegia; individuals enrolled in other interventional trials.

5. Patients with active ocular inflammation in either eye. 6. Those diagnosed with ocular diseases or presenting with clinically significant abnormalities on ophthalmic examinations.

7. Participants are currently receiving visual function training or other clinical interventions for intermittent exotropia.

8. Individuals who decline to complete the 1-year follow-up period.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: IXT with DIMS	Device: DIMS glasses; Myopia control glasses with peripheral defocus control design.
Active Comparator: IXT with DOT	Device: DOT glasses; Myopia control glasses with diffusion optics technology.
Other: Myopia with DIMS	Device: DIMS glasses; Myopia control glasses with peripheral defocus control design.
Other: Myopia with DOT	Device: DOT glasses; Myopia control glasses with diffusion optics technology.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Axial length	Measurement Tool: IOL Master 700 (Carl Zeiss Meditec AG, Jena, Germany), a high-resolution swept-source optical coherence tomography (SS-OCT) device for biometric measurement of the eye Measurement Type: Continuous parameters of ocular biometry, mainly including axial length, anterior chamber depth, lens thickness, vitreous depth and other axial dimensional parameters of the eye Unit of Measure: Ocular axial length (AL): Millimeters (mm) Anterior chamber depth (ACD): Millimeters (mm) Lens thickness (LT): Millimeters (mm) Vitreous chamber depth (VCD): Millimeters (mm)	From enrollment to the end of follow-up at 1 year
Refractive error with cycloplegia	Equipment: Cyclopentolate 1%, trial frame, standard trial lens set and logarithmic visual acuity chart for clinical refractive examination Test condition: Completed cycloplegia with cyclopentolate (C) before examination Procedure: The child wears appropriate refractive correction as required. Conduct subjective refraction step by step to determine spherical power, cylindrical power and astigmatic axis. Adjust lenses continuously until the child achieves the clearest and most comfortable vision, then record all refractive parameters and best corrected visual acuity.	From enrollment to the end of follow-up at 1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stereoacuity	Distant stereoacuity: Equipment: Random Dots Distant Test (P/N 1006, Vision Assessment Corporation, Illinois, USA) Test distance: 3 meters Range: 63 to 400 arcseconds (log stereoacuity: 1.8 to 2.6 log arcsec) Procedure: The subject identifies stereoscopic shapes at 3 meters. If unable to identify shapes at the 400 arcsec level, record as "nil stereo" (log stereoacuity value: 3.2 log arcsec). Near stereoacuity: Equipment: Randot Preschool Stereoacuity test (Stereo Optical Co., Inc, Illinois, USA) Test distance: 40 cm Test disparities: 800, 400, 200, 100, 60, and 40 arcseconds Procedure: The subject identifies shapes at 40 cm. Record the smallest disparity at which the subject correctly identifies at least two of the three shapes. If unable to identify the largest disparity (800 arcsec), record as "nil stereo" (log stereoacuity value: 3.2 log arcsec).	From enrollment to the end of follow-up at 1 year
Newcastle Control Score (NCS) score	Newcastle Control Score (NCS) score incorporates both objective and subjective measures of control into a simple grading system that differentiates and quantifies the various levels of severity in intermittent distance exotropia. Minimum and maximum values: Minimum 0, maximum 9. Interpretation of higher scores: Higher scores indicate worse control (i.e., worse outcome). A score of 0 represents perfect control, while a score of 9 represents the poorest control (constant exotropia or severe loss of control).	From enrollment to the end of follow-up at 1 year
Strabismic deviation	Strabismic deviation is measured by using the prism and alternate cover test (PACT) with accommodative targets at distance (6 m) and near (33 cm), measured after 1 hour of monocular occlusion using prisms, where the endpoint is defined as no eye movement during alternate cover testing.	From enrollment to the end of follow-up at 1 year

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Near Point of Convergence	Equipment: Near point rule Procedure: A target is moved gradually toward the center of the subject's eyes at a speed of 1 cm/s until the subject reports double vision or the examiner observes an outward deviation of one eye. The distance from the target to the spectacle plane is recorded as the NPC distance in centimeters.	From enrollment to the end of follow-up at 1 year
Fusional Vergence Amplitude	Equipment: Synoptophore (Haag Streit UK Ltd, Essex, UK) Targets: Fusion slides subtending a visual angle of 6 degrees horizontally Procedure: First, the subject moves the synoptophore arms by themselves to overlap and fuse the images (e.g., a butterfly and a cat). The examiner then slowly abducts or adducts the synoptophore tubes until the subject sees two distinct images (breakpoint). The range between the two breakpoints is recorded as the fusional vergence amplitude.	From enrollment to the end of follow-up at 1 year
Accommodative Convergence / Accommodation (AC/A) Ratio	Method: Far gradient method Test distance: 6 meters Stimulus: Minus lenses (-3.00 D) Procedure: A change in accommodation is stimulated using minus lenses. The resulting change in deviation (in prism diopters) is divided by the change in lens power (3 D). AC/A ratio = change in deviation / 3.	From enrollment to the end of follow-up at 1 year
Corneal topography	Measurement Tool: OCULUS Pentacam® (OCULUS Optikgeräte GmbH, Wetzlar, Germany), a rotating Scheimpflug camera system for anterior segment analysis Measurement Type: Continuous parameters of corneal topography, including curvature-derived parameters (anterior and posterior corneal curvature in diopters, D), elevation-derived parameters (anterior and posterior corneal elevation in micrometers, µm), and pachymetry-derived parameters (corneal thickness in micrometers, µm) Unit of Measure: Corneal curvature (keratometry, K1, K2, Kmax): Diopters (D) Corneal curvature radius: Millimeters (mm) Corneal thickness (pachymetry, CCT, thinnest point): Micrometers (µm) Corneal elevation: Micrometers (µm)	From enrollment to the end of follow-up at 1 year
Amplitude of Accommodation	Equipment: Near point rule (RAF rule) with a near visual acuity target (one line above the best corrected near visual acuity) Test distance: Starting from approximately 40 cm, moving gradually closer Procedure: The subject wears their distance refractive correction.Place the near target at 40 cm and ask the subject to keep it clear. Move the target toward the subject's eyes at a speed of approximately 1-2 cm/s until the subject reports sustained blur (cannot be made clear by further effort). Stop immediately and measure the distance from the target to the spectacle plane (in cm).	From enrollment to the end of follow-up at 1 year
Behavioral scaled questionnaire	Eye Health Behavior Assessment Scale (EHBAS) [21] that developed by Chinese National Disease Control and Prevention Administration in 2023 will be used to assess the level of eye health behaviors in children. It consists of two scales, Eye Health Behavior Assessment Scale for Kindergarten and Primary School Students in Grades 1-3 -Parent Version (EHBAS-P) and Eye Health Behavior Assessment Scale for Primary School. The content of the scale mainly includes various items such as exposure to natural light, outdoor activity time, digital screen time, reading posture and environment, and sleep time. The Scale was calculated using a score of 0 for 'cannot do it', 1 for 'sometimes do it' and 2 for 'do it'. Based on the sum of the scale's scores, the eye health behaviors of children and adolescents were classified into three levels: poor, moderate and good.	From enrollment to the end of follow-up at 1 year

Collaborators and Investigators

• Sponsor: Second Affiliated Hospital, School of Medicine, Zhejiang University

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): May 31, 2027
• Study Completion (Estimated): May 31, 2027

Study Registration Dates

• First Submitted: May 31, 2026
• First Submitted That Met QC Criteria: June 9, 2026
• First Posted (Actual): June 11, 2026

Study Record Updates

• Last Update Posted (Actual): June 11, 2026
• Last Update Submitted That Met QC Criteria: June 9, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Myopia control; DOT; Intermittent exotropia; DIMS
• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Myopia
• Other Study ID Numbers: 2025-1537

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

IPD Plan Description

Ethical and privacy restrictions: When the study protocol was approved by the ethics committee, the informed consent form did not include provisions for sharing data with third-party researchers, and participants were not asked for their consent regarding data sharing.

Institutional policy and data protection: According to the data management policy of the participating institution, research data are considered internal assets. To protect participant privacy, the data are not permitted to be shared publicly on external platforms or provided to researchers outside the primary research group.

Data sensitivity: Even with de-identification, given that the study involves a rare disease or a small sample size (or other specific reasons), there remains a potential risk of re-identification. Therefore, the decision has been made not to share the raw individual participant data.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No