Studies of the Angle Kappa and the Angle Alpha

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.

Inclusion criteria

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

Exclusion criteria

• Subject with strabismus or organic ophthalmologic pathology