Effects of adrenergic and cholinergic antagonists on diameter of nasolacrimal drainage system.
BACKGROUND
To determine the effect of an adrenergic and a cholinergic antagonist on the diameter of the lumen of the nasolacrimal drainage system.


METHODS
The asymptomatic side of 38 patients (29 women, nine men) with unilateral stenosis/obstruction of the nasolacrimal drainage system was studied. The tear meniscus height (TMH) of the asymptomatic side was normal, and the lacrimal drainage system was patent as revealed by dacryocystography. The nasolacrimal drainage system of the asymptomatic side was infused with 100 mul of 0.01% bunazosin hydrochloride, a selective alpha-1 adrenergic antagonist, or 100 mul of 0.4% tropicamide, a muscarinic and cholinergic antagonist. Dacryocystography was performed to determine the diameter of the lumen of the nasolacrimal drainage system before and after the antagonists.


RESULTS
Bunazosin reduced the diameter of the lumen significantly, and the changes were more marked in the nasolacrimal duct (NLD), especially the middle and the lower regions. The diameter of the lumen of the lacrimal sac was not changed significantly. In contrast, tropicamide did not cause any significant change in the diameter of the lumen of the nasolacrimal drainage system.


CONCLUSIONS
The alterations of the size of the lumen of the nasolacrimal drainage system, especially the NLD, by an adrenergic antagonist suggest that the lumen diameter is under continuous sympathetic tone, and the parasympathetic tone is weak.
Narioka
Junji
J
Department of Ophthalmology, Ehime University School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan. nariokaj@m2.dion.ne.jp
Ohashi
Yuichi
Y
D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007263:Infusions, Parenteral; D008297:Male; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000008:administration & dosage*; D009301:Nasolacrimal Duct / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000294:innervation; D011799:Quinazolines / Q000008:administration & dosage*; D011859:Radiography; D013564:Sympathetic Nervous System / Q000502:physiology*; D014331:Tropicamide / Q000008:administration & dosage*
D000317:Adrenergic alpha-Antagonists; D018727:Muscarinic Antagonists; D011799:Quinazolines; C018176:bunazosin; D014331:Tropicamide