management of complications of mustard gas keratitis with corneal and limbal stem cell transplantation

purpose: to report the clinical findings and compare the outcomes of different surgical techniques evolved over time in a large series of patients with delayed-onset mustard gas keratitis (mgk). methods: this interventional retrospective case series includes patients with complications of delayed mgk. medical and surgical interventions to address dry eye, limbal ischemia and limbal stem cell deficiency (lscd), and corneal complications were reviewed. outcomes of limbal stem cell transplantation techniques such as living-related conjunctival-limbal allograft (lrclal) and keratolimbal allograft (klal), as well as corneal transplantation techniques including penetrating keratoplasty (pkp) and lamellar keratoplasty (lkp) were compared. results: a total of 175 eyes of 90 patients (all male) aged 34 to 68 years were included. mean follow up was 101 months. the most common ocular complication was chronic blepharitis and dry eye. conjunctival vascular abnormalities and limbal ischemia were observed in 27.4% and 29.7% of eyes, respectively. lscd necessitating stem cell transplantation developed in 41.1% of eyes. the most common corneal signs were central and peripheral anterior stromal opacity (58.9%) followed by corneal stromal thinning (36.0%) and neovascularization (27.4%). lrclal was performed in 32 eyes (18.3%) and klal in 40 (22.9%). the rejection-free graft survival rate was 39.1% in the lrclal group and 80.7% in the klal group at 40 months with mean duration of 24.9 and 68.8 months, respectively (p=0.02). 30 eyes (17.1%) underwent pkp and 51 (29.1%) received lkp. corneal graft failure was observed in 9 (30%) pkp and 6 (11.8%) lkp eyes. the rejection-free graft survival rate was 39.0% in the pkp and 90.3% in the lkp group at 28 months with a mean duration of 29.6 and 85.0 months, respectively (p<0.001). conclusion: chemical warfare victims may ultimately develop significant ocular involvements requiring some sorts of surgical intervention. limbal and corneal abnormalities can best be managed by klal and lkp, respectively.