Long-time readers of this tip series know that I’ve been a proponent of having a clinical technician instill mydriatic drops during the pretesting phase of an eye exam. I’ve tried many different protocols for this in my practice over the years. In this article, I’ll review our past procedure and give an update of where we are now.
For many years, my staff instilled phenylephrine drops during pretesting (10% for several years, then 2.5% due to safety). I first wrote about this in 1989 in the print version of Optometric Management. This technique provided a better view of the fundus than no dilation, but we often added tropicamide later in the exam process when we needed a better view of the retinal periphery. It is still very popular among many doctors because it opens up the pupil without any cycloplegic effect.
As the standard of care evolved and as I added associate doctors to my practice, we found that we were fully dilating nearly all patients during comprehensive eye exams. We still do this today even though we have an Optomap instrument with high utilization rates. This dilation practice made the instillation of phenylephrine unnecessary since the doctor was almost always adding additional drops anyway. So, we dropped the practice of using phenylephrine as a pre-dilating agent several years ago. I use the term “pre-dilate” to refer to having a technician instill the mydriatic drop before the doctor sees the patient.
Pre-dilation with tropicamide
My practice has experimented with many different protocols for pre-dilating patients in an effort to overcome the obvious inefficiency of the doctor having to see each patient twice (before and after dilation). We have had some success, but we still face a number of challenges and I still search for the perfect method.
As we discuss and compare these clinical procedures as colleagues, we should remember that there are a variety of professional opinions about the need to dilate under various situations and the process to be followed prior to dilation.
As a quick review of the commonly available ophthalmic drugs used for pupil dilation, tropicamide is available in .5% and 1% concentrations. Tropicamide is popular because it is relatively short-acting, so it offers minimal inconvenience for the patient in the form of blurred vision and glare. Tropicamide produces mild cycloplegia. A very popular drug with the brand name Paremyd has tropicamide in only a .25% concentration and it is combined with hydroxyamphetamine, which is a sympathomimetic that increases the dilation effect. Even with the combination, however, many practitioners find they need stronger concentrations of tropicamide to obtain adequate dilation in some patients, such as those with dark irises. The other sympathomimetic eye drop that is often used with tropicamide is phenylephrine.
Here is a list of factors to consider as you develop a protocol for pre-dilation in your practice.
You may wish to only pre-dilate established patients, so the doctor has the chance to evaluate important factors like pupil response, chamber angles and systemic conditions in new patients. In many practices, the vast majority of patients seen are established, so this technique still provides a big increase in efficiency. Some practices have technicians evaluate those factors in new patients and pre-dilate everyone who meets certain criteria.
Which drug to use? Paremyd may be used as the pre-dilation drop since it is fairly mild, but it may not provide full dilation in every case.
The technician should be trained to take a special case history and to perform a pupil test before instilling mydriatic drops.
Technicians may be trained to not pre-dilate under the following situations:
Patients with chamber angles of grade 1 on the last exam.
Patients who are pregnant or nursing.
Children under age 8. The only concern here is if the child becomes overly upset about eye drops, the doctor may have trouble obtaining any clinical findings.
Patients over 40 years old wearing multifocal contact lenses.
Patients wanting a new contact lens fitting today.
Patients with an abnormal pupil exam.
Patients with extremely red eyes.
A good policy: if you are unsure, ask the doctor.
Script about dilation: “I’m going to put a drop in your eyes that will dilate your pupils so the doctor can do a thorough eye health exam. This is the same drop that you had at your last eye exam with us. The drop will make your vision a little blurry for a few hours.”
Here are some of the difficulties we have faced with pre-dilation:
Frame selection can be difficult with dilated pupils because the patient can’t see well enough. This one is a big concern for me, but we also faced this problem with the traditional dilation process when the doctor instilled the drops.
Due to all the exceptions we impose, we end up with some patients being dilated in advance and some dilated by the doctor and seen twice. This makes it difficult to predict our patient flow and it is harder to stay on schedule.
If pretesting proceeds too quickly, the drops have not had a long enough time to take effect when the doctor wants to perform the fundus exam.
Some tests, like macular pigment density, are better performed with normal pupils.
I’d love to hear from you if you have ideas and tips that help you to dilate with better efficiency.