Species variations in the pathophysiologic responses of vertebrate eyes to a chemical irritant, nitrogen mustard

Much of our knowledge of the ocular responses to irritants is derived from studies on the effects of mustards applied topically to the rabbit eye. The present study shows, however, that vertebrate eyes display profound species variations in the initial (first 6 hours) response to nitrogen mustard (NM). Rabbits and guinea pigs showed two episodes, ducks and cats one, and owl monkeys no episode of increased intraocular pressure. Development of anterior chamber flare and cellular invasion was seen in all species except ducks and owl monkeys. Pupillary constriction of differing time-course and magnitude was observed in all species except guinea pigs and ducks. At least one indomethacin-sensitive component of the NM-induced inflammatory response was demonstrated in each subprimate species, the nature of which depended upon the predominant ocular effect of prostaglandins in each. The present work suggests that while rabbits and guinea pigs may be of particular value for the study of some aspects of the ocular response to irritation and trauma, these species may be unsuitable for studying ocular inflammation and therapeutics as applicable to man.