Clinical trial NCT04886219: Studies of the Angle Kappa and the Angle Alpha
Official title: 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
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: No Eye Disorder
Keywords: Angle Kappa
Angle Alpha
Pupillary axis
Visual axis
Optical axis
Lead sponsor: Assistance Publique - Hôpitaux de Paris
Sponsor class: OTHER
First posted: 2021-05-14
Enrollment: 70
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: OTHER
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Healthy individuals without visual disorders

Brief summary: 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: 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.

Eligibility criteria: Inclusion Criteria:

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

Exclusion Criteria:

- Subject with strabismus or organic ophthalmologic pathology

Primary outcomes:
measure: Value of the angle Kappa
timeFrame: Day 0
measure: Value of the angle Alpha
timeFrame: Day 0
Secondary outcomes:
measure: Variation of the Kappa angle depending on the pupillary diameter
timeFrame: Day 0
measure: Correlation between the value of the angle Alpha and the Optic disc / fovea distance
timeFrame: Day 0
measure: Correlation between the angle Kappa and the axial length
timeFrame: Day 0
Other outcomes:
Locations:
city: Paris
country: France
facility: Hôpital Necker-Enfants Malades
Study officials:
affiliation: Assistance Publique - Hôpitaux de Paris
name: Maxence Rateaux
role: PRINCIPAL_INVESTIGATOR
affiliation: Assistance Publique - Hôpitaux de Paris
name: Dominique Brémond-Gignac, MD, PhD
role: STUDY_DIRECTOR
References:
citation: 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.