Chronic and delayed-onset mustard gas keratitis - Report of 48 patients and review of literature

Purpose: To report the clinical features of 93 eyes of 48 patients with chronic and delayed-onset mustard gas keratitis. Clinicopathologic correlation in 5 eyes and a review of related literature are presented. Design: Retrospective, noncomparative case series. Participants: Forty-eight Iranian survivors of Iraqi chemical warfare with chronic or delayed-onset mustard gas keratitis. Methods: We reviewed the symptoms, clinical findings, course, and treatment of our patients and reviewed the literature. In 5 patients, histopathologic features of corneal and conjunctival specimens were evaluated. Main Outcome Measures: Ocular findings, clinical course, treatment measures, and histopathologic studies. Results: Of 48 patients, 31 (64.6%) had chronic symptornatology, whereas 17 (35.4%) experienced delayed-onset lesions. Visual acuity at referral ranged from hand motions to 20/20. Ocular surface changes included chronic blepharitis and decreased tear meniscus in all patients, limbal ischemia (81.3%), and conjunctival vascular abnormalities (50%). Corneal signs in order of frequency were: scar or opacity (87.5%), neovascularization (70.8%), thinning (58.3%), lipoid deposits (52.1%), amyloid deposits (43.8%), and epithelial defects and irregularity (31.3%). Many patients received conservative treatment; others underwent allograft stem cell transplantation (20 eyes of 17 patients), penetrating keratoplasty (12 eyes of 12 patients), and lamellar keratoplasty (4 eyes of 3 patients). Conjunctival specimens were evaluated by light microscopy. Decreased goblet cell density, attenuated or thickened epithelium, scarring in the substantia propria associated with plasmacytic and lymphocytic infiltration, and dilated lymphatic vessels were noted. Excised corneal buttons disclosed absence of epithelium and Bowman ' s layer, fibrovascular pannus, stromal scarring, and vascularization. Conclusions: Mustard gas causes chronic and delayed destructive lesions in the ocular surface and cornea, leading to progressive visual deterioration and ocular irritation. The pathophysiologic features of these changes are not clearly identified. Excised conjunctival and corneal specimens revealed a mixed inflammatory response without any specific features. Based on the clinical appearance of the lesions and the histopathologic findings, an immune-mediated component seems possible. Ophthalmology 2005;112:617-625 (c) 2005 by the American Academy of Ophthalmology.