Incidence of Idiopathic Acquired Obstructions in the Lacrimal Drainage Apparatus.

IN the vast majority of cases the aetiology of an acquired obstruction in the lacrimal drainage apparatus remains obscure. Overt infection is a common associate, especially with obstructions involving the naso-lacrimal duct. It is still not clear whether the infection is causal or sequential to the obstruction, or whether these two factors are simply part of a wider diathesis. At the present time, this group of acquired obstructions must be regarded as idiopathic. From a perusal of the literature, it would appear that no information is available concerning the absolute incidence of these obstructions. Related work concerns the percentage of ophthalmic patients who attend with epiphora; this appears to have varied from 2*7 to 3 7 per cent. in different centres in Great Britain at different times (Traquair, 1941; Foster, 1956). Similarly, the ratio of females to males attending ophthalmic clinics with dacrocystitis is about 5:1 (Traquair, 1941); many authors claim that this ratio applies to the incidence of dacryocystitis in the population as a whole (Duke-Elder, 1952). Stallard (1958) states that naso-lacrimal duct obstruction is four times as common in females as in males, and that the left side is more commonly affected than the right. It would appear that much of this information has been derived from the relative incidence of males and females attending ophthalmic clinics with these complaints. In this respect it must be pointed out that, excluding industrial accidents, adult females normally outnumber adult males at the Outpatient Clinics of the Manchester Royal Eye Hospital, and that this probably applies to other centres in this country. Many factors contribute to the preponderance of females at these clinics, and it does not always receive sufficient attention when assessments are made of the relative incidence of ophthalmic conditions in the two sexes from statistics so derived. It is the purpose of this paper to present information concerning the near-absolute incidence of idiopathic acquired obstruction in the lacrimal drainage apparatus, and the true relative incidence of this condition in males compared with females.