To the Editor.
—There is recent interest in the side effects of mydriatic-cycloplegic solutions, reducing their total dose to the patient, yet still achieving effective mydriasis.1,2 Dr Sinclair warns against extemporaneous mixing of available solutions for sound reasons. However, I will admit to mixing equal volumes of 2.5% phenylephrine hydrochloride and 1% tropicamide, producing a solution containing 1.25% and 0.5% of each, respectively. Although the buffering seems to be a little different, they are both preserved with similar amounts of benzalkonium chloride, and the concentrations are such that precipitation should not occur. I have used this mixture for two or three years now. One drop after applanation tonometry is sufficient for an adequately dilated pupil. If the last patient of the day requires a dilated examination, 1 drop before and after tonometry will produce an adequately dilated pupil within ten minutes. My 38-year-old, +0.50-diopter eyes regain the ability to
Lindsay MB. Side Effects of Mydriatic-Cycloplegic Solutions. Arch Ophthalmol. 1981;99(9):1654. doi:10.1001/archopht.1981.03930020528030