Mustard Gas Induced Ocular Injuries

1 Mustard gas is a lipophilic, highly cytotoxic agent that rapidly penetrates tissue, and the eye is one of the organs mostly affected,[1] but skin, respiratory, gastrointestinal, and renal systems as well as the bone marrow may also be affected.[2] Mustard gas related ocular injuries can be divided into immediate, chronic, and delayed‐onset phases. Acute manifestations of varying degrees, including eyelid erythema and edema, chemosis, subconjunctival hemorrhage, epithelial edema, punctate erosions, and corneal epithelial defects, develop in 75–90% of exposed individuals and can follow three different courses: complete resolution, persistent smoldering inflammation (chronic form), or reappearance of lesions after a latent period of quiescence (delayed form).[3,4] Late complications, developing after 1 to 40 years, can cause progressive and permanent reduction in visual acuity and even blindness, and they occur in approximately 0.5% of those initially severely wounded.[2,3] A wide range of late ocular involvements have been reported, which include chronic blepharitis, decreased tear meniscus, conjunctival vessel tortuosity, limbal ischemia and stem cell deficiency (LSCD), corneal scarring and neovascularization, thinning, epithelial irregularity, recurrent or persistent epithelial defects, and secondary degenerative changes including lipid/ amyloid deposits.[2,3,5] The management of the acute phase is relatively straightforward, chiefly consisting of symptomatic therapy to address the patient’s discomfort and ocular inflammation. This approach includes topical antibiotics, preservative‐free lubricants, and anti‐inflammatory agents. Topical steroids and non‐steroidal anti‐inflammatory drugs are found to be beneficial in ameliorating the initial inflammatory response and in postponing the development of corneal neovascularization, when given during the first week after exposure. However, to date, no definitive treatment for delayed‐onset mustard gas induced keratits (MGK) is available. Therapy is tailored based on the type and severity of involvements and varies from symptomatic treatment to surgical interventions for dry eye, corneal epithelial instability, limbal stem cell deficiency, and Mustard Gas Induced Ocular Injuries