Chemical Eye Injury Case Studies

Discussion :
Chemical eye injuries could occur as a result of an accidental exposure at work which is the most common case or an accidental exposure at home, in some instance it could be a result of a criminal assault. It could happen with exposure to alkali or acidic agents, solvents & irritants in form of liquid , powder , solids or vapor. Of these alkali injuries occur more frequently(1-3).
Alkali burns are more severe than acidic burns, because of their rapid penetrating effect through the cornea. Alkali agents causes saponification of fatty acids in the cell membrane with subsequent distractiondestruction of mucopolysaccharides , at same time it enhances the collaginolysis process causing tissue necrosis and perforation. IOn the other

The New classification system "Dua classification" (see table3) which developed later based on clock hours of limbal ischemia in addition to degree of conjunctival involvement (1,9). Both these scales are necessary to predict the prognosis of the patient after the chemical injury.

Table 2 : Roper-Hall classification of ocular chemical injuries
GRADE PROGNOSIS CORNEA CONJUNCTIVA / LIMBUS
I Good Abrasion No limbal ischemia
II Good Haze cornea with visible iris details < 1/3 limbal ischemia
III Guarded Total epithelial loss , haze cornea with obscured iris details 1/3 - 1/2 limbal ischemia
IV Poor Opaque cornea with obscured both iris & pupil details > 1/2 limbal ischemia

McCulley Clinical Course: MuCulley divided the clinical course of chemical eye injuries into four phases as following (1,2,10).
1. Immediate phase [ day 0 ] : start with the injury of the cornea , conjunctiva and corneal limbus. As epithelial stem cells are anatomically located in the limbus, so the degree of limbal ischemia is critical indicator of the prognostic

The management is divided into three stages : emergency , acute phase & late phase (1-6).
Emergency phase management:
1) Early copious irrigation till the pH is neutralized :
Chemical burn is the only ocular injury that needs an immediate emergency treatment with copious irrigation without taking history and even before the primary ophthalmological assessment. Start by application of topical anaesthesia drops to relieve the blepharospasm & pain. Document the status of the eye pH with Litmus paper. Eyelid speculum should applied to immobilize the eyelids. It is important to double evert the upper eyelid and sweep the fornix with moist cotton swab to identify and remove any foreign body, and to sweep the lower fornix as well.
Irrigation should be started for at least 30 minute and continue till the pH is neutralized. The ideal fluids for irrigation are: Balanced Salt Solution (BSS) , Ringer Lactate, Normal Saline or tap water if sterile fluid is not available, never use an acidic or alkali solutions to normalize the pH. the practical irrigating devises which are used are intravenous tubing, nasal cannula , irrigating eyelid speculum and irrigating contact lens such as Morgan