Mydriatic solution for outpatient indirect ophthalmoscopy
S. H. Sinclair, V. Pelham, R. Giovanoni and C. D. Regan
A mydriatic used for outpatient indirect ophthalmoscopy should produce
prompt, maximal, transient mydrasis after a single instillation.
Cycloplegia or systemic side effects should be minimal. A solution of
tropicamide with phenylephrine hydrochloride seems to achieve this most
effectively. In a general retina clinic population, the percentage of
pupils dilated, the degree of dilation, and the resistence of the dilation
to intense illumination were used to evaluate various concentrations of the
drugs. Eight-tenths percent tropicamide with 5% phenylephrine adequately
dilated 98.8% of the eyes, among which 25% had dark irides and 9% were
receiving miotic therapy. Reduction of the concentration of either
component produced less adequate mydriasis; an increase of the tropicamide
concentration resulted in a saturated solution with drug precipitate
forming on storage and a less adequate dilation. With the optimal
combination, 1 drop adequately dilates the general population; 2 drops
appear on more effective than 1.
