casualties showed improvement of the cornea, and only 1 percent had severe Class IIIb corneal lesions (Hughes, 1945a). A report of 1,097 patients treated at Edgewood Arsenal during the 17 months preceding March 1, 1943, showed that 91 percent of the injuries were due to mustard agent vapor, and of that number 78 percent had eye burns (Uhde, 1946). Eighty of these patients were exposed to a sudden break in the shell filling line, which released large quantities of mustard agent vapor. The remaining 93 percent were exposed to slow leaks that were not detected by smell. Unfortunately, there have been no long-term studies of these patients to determine their ocular status many years after exposure.
The British reported many thousands of eye casualties during World War I. Sulfur mustard was responsible for 77 percent of all gas injuries in WWI; of these, 75 percent were relatively mild conjunctival irritations, forcing hospital care for an average of two weeks before return to active duty (Gilchrist and Matz, 1933; Hughes, 1942). Another 15 percent were described as intermediate, with incapacitation for four to six weeks. Finally, 10 percent were severe, requiring hospitalization or rehabilitation for a four- to six-month period before stabilizing (Hughes, 1942). A total of 51 British soldiers were reported as blinded, and there were 180 vision-related pensions (Phillips, 1940). Phillips (as cited in Hughes, 1945a) also reported 80 patients with late recurrent ulceration of the cornea following exposure to sulfur mustard in WWI. He stated that there were a total of 300 reported cases of delayed keratitis as of 1939.
Two French reports describe only a handful of ocular lesions. Teulieres (as cited in Hughes, 1942) reported on 1,500 mustard gas casualties, of which only 23 patients sustained ocular lesions severe enough to necessitate observation. Of these, 3 patients showed ulceration of the cornea and 1 developed inflammation of the entire eye (panophthalmitis). In a parallel report of 1,800 sulfur mustard casualties, Beauvieux (1920) found only 2 patients in whom severe corneal ulceration developed; both cases ultimately recovered useful vision. Beauvieux also examined the retinal blood vessels and condition of the retina in 120 cases of severe generalized sulfur mustard lesions and noted venous dilatations in 34 percent and hyperemia of the optic disk in 23 percent.
If all of these reports are combined, up to 90 percent of casualties would be expected to have ocular involvement, with symptoms peaking 6 to 12 hours after exposure. However, 90 percent of these cases would have no significant corneal involvement. Common symptoms included gritty sensation, conjunctivitis, chemosis (edema of the conjunctiva