Vitamin A deficiency reduces mucus lubrication of the eye
•Which leads to drying of the conjunctiva and keratinization of its epithelial cells
These dry and keratinized cells are desquamated into the conjuctival sac as debris
With each blink, the eyelids swipes the debris toward the center of the eye
Corynebacterium xerosis is a commensal bacteria found in the skin and mucous membranes of humans.
•These bacteria release gas as a part of their metabolism.
These bacteria get mixed with the cell debris
With repeated blinking, the debris containing keratinized cells and gas forming bacteria accumulate on the sides of the cornea (at 3° and 9 ° clock position)
•More often seen on the lateral side of the cornea i.e. the 9 ° clock position
The gases released by the bacteria cause the foamy appearance of the debris accumulated on the sides of the cornea
References:
• Gilbert C. The eye signs of vitamin A deficiency. Community Eye Health. 2013;26(84):66-7. PMID: 24782581; PMCID: PMC3936686.
• https://eyewiki.aao.org/Xerophthalmia
Video on Bitot's Spot formation: https://www.youtube.com/watch?v=cL6_uEK7cRU&t=1s
HINDI video on Bitot's Spot formation: https://www.youtube.com/watch?v=cL6_uEK7cRU
Same blog in HINDI (विटामिन A की कमी से बिटोट स्पॉट का गठन क्यों होता है?
): https://ihatepsm.com/blog/%E0%A4%B5%E0%A4%BF%E0%A4%9F%E0%A4%BE%E0%A4%AE%...
Why do Bitot’s Spots form in Vitamin A deficiency?: https://ihatepsm.com/blog/why-do-bitot%E2%80%99s-spots-form-vitamin-defi...
