Optometric Management Tip # 223 - Wednesday, April 26, 2006
More Thoughts on Pupil Dilation
Last week I covered
an idea to make pupil dilation more efficient in the office, and this week I’ll
offer some more tips and ideas on that topic.
I recently acquired two computerized refraction systems in my practice, which
allows technicians to assist with subjective refraction testing. While most
doctors utilize these instruments to save time spent on gathering refractive
data, there is an additional benefit with pupil dilation. Once the subjective
refraction is done, the technician can check anterior chamber angles with a slit
lamp and fully dilate the patient with tropicamide. When the doctor sees the
patient, he is already dilated, saving the need to instill drops and see the
patient back a second time. The distance subjective refraction can even be fine
tuned or confirmed by the doctor in the dilated state.
Pre-dilate older patients
Some doctors have their technicians pre-dilate their patients that are 55 years
of age or older, using a drug with tropicamide. The doctor does the refraction
with the eye dilated and somewhat cyclopleged, but the reasoning is that
patients in this age group have little accommodation and the refractive result
will be the same.
Instill drops upon entering
This technique works well in conjunction with last week’s tip when the eyes are
pre-dilated with phenylephrine 2.5%. With the phenylephrine already working, the
doctor may add 1 drop of tropicamide to each eye immediately after greeting the
patient during the doctor part of the visit. Then the doctor does his or her
usual tests: reviews case history, refraction, slit lamp, discusses some of the
findings and recommendations, and finally does the fundus exam. At this point,
the phenylephrine has had about 40 minutes to work and the tropicamide might
have had close to 15 minutes. This technique can provide a fully dilated pupil
in many patients and allow a peripheral retinal exam with a BIO.
Choice of drugs
We have a need for several different mydriatic drops for various applications
and types of patients. Some patients, such as those with dark pigmentation and
diabetics, are harder to dilate and may require a stronger drug concentration.
In some cases we want a stronger cycloplegic affect for checking true refractive
status or for pain relief. In some cases we want a fast acting drug that has a
short acting cycloplegic effect, so our patients can return to work with little
inconvenience. Generally, we use phenylephrine (Neosynephrine) 2.5%, tropicamide
(Mydriacyl) .5% and 1%, and cyclopentolate (Cyclogyl) .5% and homatropine 5%.
For routine fundus evaluations Paremyd is an excellent choice because it has
only .25% tropicamide – less than any other formulation. This low dose is
sufficient for good pupil dilation, but it has reduced cycloplegic action and
quicker recovery time. Paremyd is a combination drug: tropicamide along with
hydroxyamphetamine (which used to be sold under the brand name Paredrine), so
there is a cross action mydriasis. Hydroxyamphatmine does not cycloplege and is
similar to phenylephrine. Paremyd was off the market for awhile – but is now
available again from Akorn.
Best wishes for continued success,
Neil B. Gailmard, OD, MBA, FAAO
Chief Optometric Editor, Optometric Management