Sidekalvad

Sidekalvad, known in medical terms as the conjunctiva, is a thin mucous membrane that lines the inside of the eyelids (palpebral conjunctiva) and covers the anterior surface of the eyeball (bulbar conjunctiva). The two parts meet at the fornix, a recess that forms the junction between the lid margin and the globe.

Histology and anatomy: The conjunctival epithelium is typically non-keratinized and stratified, with goblet cells that secrete mucins contributing to the tear film. The underlying substantia propria contains blood vessels, immune cells, and accessory glands. The tissue is richly innervated and receives sensory input via branches of the trigeminal nerve. The bulbar and palpebral portions are connected at the fornix, allowing the eyelids to move over the globe without compromising the surface.

Functions: The conjunctiva provides a protective barrier against dust and micro-organisms, contributes to lubrication and tear film stability through mucus production, and participates in local immune defense. It also helps maintain moisture of the ocular surface and supports normal blinking mechanics.

Clinical relevance: Inflammation of the conjunctiva is called conjunctivitis and can be caused by infections (bacterial or viral), allergies, or irritants. Other common conditions affecting the sidekalvad include dryness (keratoconjunctivitis sicca), pinguecula, pterygium, and subconjunctival hemorrhage. Ocular surgeries may involve conjunctival grafts or incisions, reflecting the tissue’s accessibility and healing properties.