Conjunctival fornix

Anatomical structure of the eye

Conjunctival fornix

Sagittal section of the eye showing the conjunctival fornix
Latin	Fornix conjunctivae
Precursor	Surface ectoderm
System	Visual system

The conjunctival fornix is a crucial anatomical structure in the human eye, forming part of the conjunctiva, which is the mucous membrane that covers the front of the eye and lines the inside of the eyelids. The fornix serves as a junction between the bulbar and palpebral conjunctiva, allowing for the free movement of the eyelids over the surface of the eye.

Anatomy

The conjunctival fornix is divided into four sections:

• Superior fornix: Located beneath the upper eyelid, it is the fold of conjunctiva that connects the palpebral conjunctiva of the upper eyelid to the bulbar conjunctiva covering the sclera.
• Inferior fornix: Situated beneath the lower eyelid, it connects the palpebral conjunctiva of the lower eyelid to the bulbar conjunctiva.
• Medial fornix: Found near the medial canthus, it is less pronounced due to the presence of the plica semilunaris and the caruncle.
• Lateral fornix: Located near the lateral canthus, it is generally deeper than the medial fornix.

Function

The primary function of the conjunctival fornix is to allow the eyelids to move freely over the surface of the eye without causing damage or irritation. It acts as a reservoir for tears and helps in the distribution of the tear film across the eye, which is essential for maintaining corneal health and clear vision.

Clinical Significance

The conjunctival fornix can be involved in various ocular conditions:

• Conjunctivitis: Inflammation of the conjunctiva, often involving the fornices, leading to redness, swelling, and discharge.
• Dry eye syndrome: Insufficient tear production or poor tear quality can affect the fornices, leading to discomfort and potential damage to the ocular surface.
• Foreign bodies: The fornices can trap foreign bodies, which may require careful removal to prevent irritation or infection.
• Surgical considerations: During ocular surgeries, such as cataract surgery, the fornices are often manipulated to gain access to the eye.

Development

The conjunctival fornix develops from the surface ectoderm during embryogenesis. Proper development is crucial for the formation of a functional conjunctival sac, which is necessary for normal eye movement and tear distribution.

Also see

• Conjunctiva
• Tear film
• Eyelid
• Ocular surface disease