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What is Common cause of childhood blindness are all EXCEPT and explain in detail?
(Dacrocystitis): (546-48- Parson 21st/ edition; 514-Nema 6th/ed; 477-Khurana 5th/ed)Causes of childhood blindness* Vitamin A deficiency* Measles* Conjunctivitis* Ophthalmia- neonatorum* Congenital cataract* Retinopathy of prematurity (ROP)* Common causes of childhood blindness in India include corneal scar (26%). Congenital anomalies of the globle (25%) disease of the retina (21%) and cataract (12%). The corneal scarring is mainly due to vitamin A deficiency, trachoma and conjunctivitis (514- Nema 6th/ed)* Nutritional blindness can occur at any age but is most frequently seen in under privileged young children in the developing countries because the main contributing factors - measles, frequent diarrhea, protein energy malnutrition and other febrile illness are more common in them, Severe Karatomalacia is usually seen below 5 years of age and is particularly common in children between 6 months and 3 years of age. Since affected individuals are young the impact in number of blind person- years is tremendousCauses of impaired vision in childhoodAnatomical classificationWhole globe microphthalmos, anophthalmos, phthisis bulbi atrophic bulbiCornea: scar, anterior staphyloma, dystrophyLens: cataract, dislocation, aphakiaUvea: aniridia, coloboma, uveitisRetina: retinopathy of prematurity, retinal dystrophy, retinal detachment, vasculitisGlaucoma: buphthalmosOptic nerve optic atrophy, hypoplasiaOther: cortical blindness, amblyopiaAetiological classificationHereditary: chromosomal disorder, single-gene defectsIntrauterine: congenital rubella, foetal alcohol syndromePerinatal: ophthalmia neonatorum, retinopathy of prematurity, birth traumaChildhood: vitamin A deficiency, measles, traumaUnclassified impossible to determine the underlying cause