Studies of the Angle Kappa and the Angle Alpha

NCT ID: NCT04886219

Last Updated: 2025-09-19

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Total Enrollment

70 participants

Study Classification

OBSERVATIONAL

Study Start Date

2021-05-19

Study Completion Date

2021-10-04

Brief Summary

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Anatomical ophthalmological connections and their dynamics are still debated in the scientific community. However, their considering is essential in many surgeries (strabismus, cataract, refractive...) or in clinical practice.

The correlation between these biometric values would make it possible to refine the knowledge related to these landmarks and thus offer better ophthalmological management by integrating these variables into the clinical examination.

The aim of the study is to analyze the correlation between the angle alpha and the angle kappa in a healthy individual without ophthalmologic disorder.

Detailed Description

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The angle kappa corresponds to the angle formed between the visual axis (line between the point of fixation and the fovea: area of the retina allowing precise vision) and the pupillary axis (line passing through the center of the pupil and perpendicular to the cornea). The angle alpha corresponds to the angle formed between the visual axis and the optical axis (line passing through the nodal point of the eye and corneal center).

In theory, the angle kappa and angle alpha are equal; but physiological corectopy in the nasal position induces a variation between these two angles; the angle kappa being generally less than the angle alpha without a correlation being established. Also, pupillary constriction causes a variation in the position of the center of the pupil. The angle kappa therefore exhibits a variation depending on the expansion.

Anatomical ophthalmological connections and their dynamics are still debated in the scientific community. However, their considering is essential in many surgeries (strabismus, cataract, refractive ...) or in clinical practice.

The correlation between these biometric values would make it possible to refine the knowledge related to these landmarks and thus offer better ophthalmological management by integrating these variables into the clinical examination.

The aim of the study is to analyze the correlation between the angle alpha and the angle kappa in a healthy individual without an eye disorder.

Conditions

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No Eye Disorder

Study Design

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Observational Model Type

OTHER

Study Time Perspective

PROSPECTIVE

Study Groups

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Healthy individual

Healthy individual

Eye examination

Intervention Type OTHER

* Multimodal fundus imaging (color fundus photography, optical coherence tomography (OCT))
* orthoptic assessment (Visual acuity, Refraction, Cover test, Stereopsis evaluation
* ocular biometry
* corneal topography
* monocular photographs in photopic and scotopic condition

Interventions

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Eye examination

* Multimodal fundus imaging (color fundus photography, optical coherence tomography (OCT))
* orthoptic assessment (Visual acuity, Refraction, Cover test, Stereopsis evaluation
* ocular biometry
* corneal topography
* monocular photographs in photopic and scotopic condition

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

\- Informed major subject not opposing to their participation in the study

Exclusion Criteria

\- Subject with strabismus or organic ophthalmologic pathology
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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URC-CIC Paris Descartes Necker Cochin

OTHER

Sponsor Role collaborator

Assistance Publique - Hôpitaux de Paris

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Maxence Rateaux

Role: PRINCIPAL_INVESTIGATOR

Assistance Publique - Hôpitaux de Paris

Dominique Brémond-Gignac, MD, PhD

Role: STUDY_DIRECTOR

Assistance Publique - Hôpitaux de Paris

Locations

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Hôpital Necker-Enfants Malades

Paris, , France

Site Status

Countries

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France

References

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Rateaux M, Vienne-Jumeau A, Bremond-Gignac D, Robert MP. Fluctuations in angle lambda with the pupil diameter and correlations with biometric values in a healthy population. Ophthalmic Physiol Opt. 2025 Aug 14. doi: 10.1111/opo.70006. Online ahead of print.

Reference Type BACKGROUND
PMID: 40810703 (View on PubMed)

Rateaux M, Bremond-Gignac D, Robert MP. From monocular photograph to angle lambda: A new clinical approach for quantitative assessment. J Binocul Vis Ocul Motil. 2022 Jul-Sep;72(3):169-175. Epub 2022 Jun 22.

Reference Type BACKGROUND
PMID: 35731900 (View on PubMed)

Other Identifiers

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2020-A03370-39

Identifier Type: OTHER

Identifier Source: secondary_id

APHP210289

Identifier Type: -

Identifier Source: org_study_id

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