Commonest site of the foreign body lies in
(Subtarsal sulcus): Ref: 370-73-P, 402-408-KH Intra ocular foreign bodies Chip of iron and steel (90%) are commonest foreign body Mechanical effects - In general these include comeal or/and scleral perforation, hyphaema, iris hole, rupture of the lens and traumatic cataract, vitreous haemorrhage and/or degeneration, choroidal perforation, haemorrhage and inflammation, retinal hole haemorrhage, oedeama and detachment. Extraocular foreign bodies: Small foreign body impact on the comeal or conjuctival surface (674-K) * Adhere to the superior palpebral conunctiva in the subtarsal sulcus and abrade the cornea with every blink. A pathognomic pattern of linear comeal abrasion may be seen. A subtarsal foreign body is easily missed unless the upper lid is everted. * Ascend and lodge in the superior conjucntival fornix and produce chronic conjunctivitis * Impact in the bulbar conjunctiva * Impact in the comeal epithelium or stroma to a depth proportional to the velocity of the foreign body * A very high velocity foreign body may penetrate the cornea or sclera and lodge intraocularly.
Bulbar conjunctiva
Limbus
Subtarsal sulcus
Cornea