Studies of the Angle Kappa and the Angle Alpha (EKAPS)

Studies of the Characteristics of the Angle Kappa and the Angle Alpha in the Healthy Individual. Studies of the Angle Kappa and the Angle Alpha

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.

Study Overview

• Status: Completed
• Conditions: No Eye Disorder
• Intervention / Treatment: Other: Eye examination

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 70

Contacts and Locations

Study Locations

• France
  • Paris, France, 75015
    • Hôpital Necker-Enfants Malades

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Healthy individuals without visual disorders

Description

Inclusion Criteria:

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

Exclusion Criteria:

- Subject with strabismus or organic ophthalmologic pathology

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Healthy individual	Other: 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Value of the angle Kappa	Semi-automatic digital method of measurement by eye photography	Day 0
Value of the angle Alpha	Semi-automatic digital method of measurement by eye photography	Day 0

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Variation of the Kappa angle depending on the pupillary diameter	Variation in the same individual. Value of the Kappa angle using the semi-automatic method of measurement by ocular photography in photopic and scotopic conditions & measurement of the pupillary diameter using the photographs obtained	Day 0
Correlation between the value of the angle Alpha and the Optic disc / fovea distance	Angle Alpha value using the semi-automatic method of measurement by eye photography and the distance between the optic disc and the fovea	Day 0
Correlation between the angle Kappa and the axial length	Value of the angle Kappa and Alpha using the semi-automatic method of measurement by eye photography and Value of the axial length measured by biometry IolMaster 500 (Carl Zeiss)	Day 0

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris
• Investigators: Principal Investigator: Maxence Rateaux, Assistance Publique - Hôpitaux de Paris

Study record dates

Study Major Dates

• Study Start (ACTUAL): May 19, 2021
• Primary Completion (ACTUAL): October 4, 2021
• Study Completion (ACTUAL): October 4, 2021

Study Registration Dates

• First Submitted: May 10, 2021
• First Submitted That Met QC Criteria: May 10, 2021
• First Posted (ACTUAL): May 14, 2021

Study Record Updates

• Last Update Posted (ACTUAL): October 29, 2021
• Last Update Submitted That Met QC Criteria: October 28, 2021
• Last Verified: June 1, 2021

More Information

Terms related to this study

• Keywords: Pupillary axis; Angle Kappa; Angle Alpha; Visual axis; Optical axis
• Additional Relevant MeSH Terms: Eye Diseases
• Other Study ID Numbers: APHP210289; 2020-A03370-39 (OTHER: IDRCB number)

Plan for Individual participant data (IPD)

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

Drug and device information, study documents

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