Pupillary dilatation with single eyedrop mydriatic combinations

We studied the mydiatic effect of three solutions containing a combination of two mydriatic drugs in 80 adult patients. The solutions tested were cyclopentolate HCl 0.5% with phenylephrine 2.5%, tropicamide 0.5% with phenylephrine 2.5%, and tropicamide 1.0% with phenylephrine 2.5%. We evaluated the effect of prior instillation of proparacaine 0.5% eyedrops. All three mydriatic combination solutions evaluated produced pupillary dilatation of about 7 mm within 60 minutes. Additional pupillary dilatation of 1 mm occurred when proparacaine was instilled before the mydriatic combination eyedrop. Mydriasis was resistant to bright light during indirect ophthalmoscopy in all patients. Pupils of younger patients dilated better than those of older patients, but sex and iris color were factors in the amount of pupillary dilatation obtained. Wide and sustained pupillary dilatation can be obtained for satisfactory indirect ophthalmoscopy by the instillation of one drop of proparacaine solution followed by a single drop of any of the three mydriatic combination solutions evaluated. By eliminating the need for multiple instillations of drugs, the use of a single eyedrop mydriatic combination is convenient in terms of time saved and also lessens the change of systemic drug toxicity.