Morphological Characteristics of the Maxillomandibular Region in a 3D Representation and the Refractive Status of the Eye

NCT07460557 | Recruiting

• 1 other identifier: 0003-01/25-05/14
• Study Type: observational
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this observational study is to learn more about the relationship between the size and shape of the eye and the shape of the face in healthy young adults. In particular, the study focuses on whether specific eye measurements are linked to certain facial characteristics after growth and development have been completed. The main question it aims to answer is: Does the size and internal structure of the eye relate to the three-dimensional shape of the face in young adults aged 21 to 25, and are these relationships different in people who are nearsighted (myopic), farsighted (hyperopic), or have normal vision (emmetropic)? Refractive errors such as nearsightedness and farsightedness are very common and are largely influenced by the length of the eye (axial length) and other internal eye measurements. During childhood and adolescence, it develops at the same time as the eye socket (orbit) and the bones of the face. However, most previous studies have examined either the eye or the bony orbit separately. Very few have combined detailed eye measurements with modern three-dimensional (3D) facial measurements in the same individuals. This study will include 120 healthy young adults between 21 and 25 years of age, after facial growth is complete. Participants will be divided into three groups based on their refractive status: myopic (nearsighted), emmetropic (normal vision), and hyperopic (farsighted), with similar numbers of men and women in each group. All participants will undergo a standard ophthalmologic examination. This will include measurement of visual acuity, refraction (to determine glasses prescription), and detailed eye biometry using a non-contact optical device (IOLMaster 700). The measurements will include axial length (eye length), corneal curvature, anterior chamber depth, lens thickness, and corneal diameter (white-to-white). These are routine, non-invasive measurements commonly used in clinical eye care. In addition, participants will undergo non-invasive 3D facial imaging. A short video of the face will be recorded while a camera moves around the participant. Using photogrammetry software, this video will be converted into a precise 3D model of the face. From this model, specific facial landmarks will be identified, and distances and proportions of different facial regions (upper, middle, and lower thirds of the face; cheek width; jaw width; chin projection) will be measured. This method does not involve radiation and does not cause discomfort. The researchers will then analyze whether there are statistical relationships between eye measurements and facial dimensions. They will also compare the three refractive groups to determine whether certain facial patterns are more common in myopic, emmetropic, or hyperopic individuals. Participation is voluntary. All participants will sign informed consent before enrollment. The study has been approved by relevant ethics committees and will be conducted according to international ethical standards. All data will be anonymized and stored securely. No additional risks are expected beyond those associated with a routine eye examination. The results of this study may improve understanding of how eye growth and facial development are related. In the long term, this could contribute to better knowledge of the anatomical background of refractive errors and support future interdisciplinary research in ophthalmology, orthodontics, and craniofacial medicine.

Conditions

Refractive Errors

Outcome Measures

Primary Outcomes (1)

• Axial length (AL)

  Axial length is the distance from the anterior corneal surface to the retinal pigment epithelium along the optical axis of the eye. It represents the anatomical length of the eyeball and is a principal determinant of refractive status, with increased axial length typically associated with myopia.

  Assessed once during the ophthalmologic examination.

Study Arms (1)

Healthy young adults stratified by refractive status

Healthy young adults aged 21 to 25 years, of the same ethnic background, with normal ocular health and best-corrected visual acuity ≥ 1.0, stratified into myopic, emmetropic, and hyperopic groups, and with body mass index between 18.5 and 24.9 kg/m².

Other: No intervention; Observational study

Interventions

No intervention; Observational study OTHER

No intervention; Observational study

Healthy young adults stratified by refractive status

Eligibility Criteria

• Age: 21 Years - 25 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Probability Sample

Study Population

Study participants will be selected from the population of healthy young adults aged 21 to 25 years who undergo routine ophthalmologic examination at the participating healthcare institution. The source population consists of individuals of the same ethnic background with completed craniofacial growth, normal ocular health, and no history of ocular or facial surgery, craniofacial anomalies, orthodontic treatment affecting maxillomandibular relationships, ocular or facial trauma, strabismus, amblyopia, or systemic diseases influencing facial morphology or ocular biometric parameters. Eligible individuals must have best-corrected visual acuity ≥ 1.0 and a body mass index between 18.5 and 24.9 kg/m². Participants will be stratified according to refractive status into myopic, emmetropic, and hyperopic groups.

You may qualify if:

• Healthy young adults aged 21 to 25 years.
• Same ethnic background (to reduce population-related morphological variability).
• Best-corrected visual acuity ≥ 1.0.
• Normal findings of the anterior and posterior ocular segments.
• Refractive status determined by objective autorefractometry and confirmed by subjective refraction.
• Body mass index (BMI) between 18.5 and 24.9 kg/m².
• Willingness to participate and provision of written informed consent.

You may not qualify if:

• Previous ocular surgery.
• Previous facial surgery.
• Craniofacial anomalies.
• Active or previous orthodontic therapy that may affect maxillomandibular relationships.
• Strabismus.
• Amblyopia.
• Ocular trauma.
• Facial trauma.
• Systemic diseases that may affect facial morphology or ocular biometric parameters.

Sponsors & Collaborators

• University of Zagreb: lead

Study Sites (1)

University of Zagreb School of Dental Medicine

Zagreb, Croatia

RECRUITING

MeSH Terms

Conditions

Refractive Errors

Interventions

Observation

Condition Hierarchy (Ancestors)

Eye Diseases

Intervention Hierarchy (Ancestors)

Methods; Investigative Techniques

Central Study Contacts

Maja Malenica Ravlić, MD

CONTACT

+38598670083; majamalenicaravlic@gmail.com

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD

Study Record Dates

• First Submitted: March 3, 2026
• First Posted: March 10, 2026
• Study Start: March 1, 2026
• Primary Completion: June 1, 2026
• Study Completion: July 1, 2026
• Last Updated: March 10, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL

Locations

CR (1)