All are common causes of childhood blindness except

Congenital dacryocystitis [Ref: Khurana 4/e,p 369, 447; Parson's 20/e, p 530-531 Repeat from May07 Causes of impaired vision in childhood Anatomical classification Whole globe: microphthalmos, anophthalmos, phthisis bulbi, atrophic bulbi Cornea: scar, anterior staphyloma, dystrophy Lens: cataract, dislocation, aphakia Uvea: aniridia, coloboma, uveitis Retina: retinopathy of prematurity, retinal dystrophy, retinal detachment, vasculitis Glaucoma: buphthalmos Optic nerve optic atrophy, hypoplasia Other: coical blindness, amblyopia Aetiological classification Hereditary: chromosomal disorders, single-gene defects Intrauterine: congenital rubella, foetal alcohol syndrome Perinatal: ophthalmia neonatorum, retinopathy of prematurity, bih trauma Childhood: vitamin A deficiency, measles, trauma Unclassified: impossible to determine the underlying cause Congenital dacryocystitis (also k/a dacryocystitis neonatorum) is an inflammation of the lacrimal sac occurring in newborn infants, and thus also known as dacryocystitis neonatorum it is d/t stasis of secretion in the lacrimal following congenital blockage in the nasolacrimal duct. congenital dacryocystis presents as - epiphora, usually developing after 7 days of bih, followed by copious mucopurulent discharge from the eyes - swelling on the sac area It may be complicated by - recurrent conjunctivitis - acute on chronic dacryocistitis - lacrimal abscess & fistula formation