Sulfur mustard-induced ocular surface disorders.

Sulfur mustard is a vesicant agent with severe irritating effects on living tissues, including skin, mucous membranes, eyes, and respiratory tract. The eyes are the most susceptible tissue to mustard gas effects, and varying degrees of ocular involvement are seen in 75% to 90% of exposed individuals. Most cases resolve uneventfully; however, a minority of exposed patients will have a continuous process, which manifests clinically either as a persistent smoldering inflammation (chronic form) or late-onset lesions appearing many years after a variable "silent" period (delayed form). Distinctive features common to most cases with chronic involvement include chronic blepharitis, meibomian gland dysfunction, dry eye, limbal ischemia, limbal stem cell deficiency, aberrant conjunctival vessels, corneal neovascularization, and secondary degenerative changes, including lipid and amyloid deposition and corneal irregularity, thinning and scarring. Most cases can be managed with conservative measures, eg, preservative-free artificial tears, lubricants, and topical steroids. Punctal plugs or punctal cauterization is helpful in moderate and severe forms of injury. Surgical modalities, including lateral or medial tarsorrhaphies, amniotic membrane transplantation, lamellar or penetrating keratoplasty, and stem cell transplantation have been used.