Keep the Fun in Fundus With Efficient Pupillary Dilation
By Leo Semes, OD, FAAO
During the 10th anniversary meeting of the Optometric Glaucoma Society in October, the Distinguished Service Award was presented to Louis Catania, OD. For those readers unfamiliar with him, he was instrumental in implementing the idea of optometrists administering primary eye care. Much of Dr. Catania’s thrust involved the use of therapeutics, but we should be mindful of the role that diagnostic agents play, specifically those to dilate the pupil. We furthered patient care significantly in accomplishing this milestone.
Pupillary Dilating Agents
Some comparisons among pupillary dilating agents were undertaken in the early 1980s and involved what was thought be a safer alternative to phenylephrine (Semes and Bartlett, 1982). Alternative combination solutions have been investigated and reported as well (Krumholz et al, 2006).
Subsequent to those reports, Paremyd (Akorn, Inc.) was introduced. Interestingly, this formulation was suggested by another optometrist, Dr. Michael Larkin, in California. It consisted of a lower concentration (0.25%) of tropicamide compared to what was available alone in combination with 1% hydroxyamphetamine. The idea was to produce rapid mydriasis with a shorter recovery time. Tropicamide is an anti-cholinergic agent acting to disengage the sphincter muscle, while the hydroxyamphetamine component is an indirect-acting adrenergic agent preventing the reuptake of norepinephrine within the dilator fibers. It was a successful mydriatic agent, but for a number of reasons lost favor and fell from commercial presence.
Figure 1. Posterior synechiae.
Recently, this very useful product has become available once again. Obtaining a stereoscopic evaluation of the ocular fundus has been recognized both as a significant component of an ophthalmic examination and as a lynchpin of glaucoma evaluation (Krumholz et al, 2006). Stereoscopic examination of the optic nerve head is critical to optic nerve assessment. But not to be forgotten is stereoscopic examination of the macula, retinal vasculature, vitreous, and peripheral retina. Dilation of the pupil allows us to look into the room through the doorway rather than through just the keyhole, to paraphrase another of my mentors, Joseph Toland, MD.
Managing Pupillary Dilation
Pupillary dilation goes a long way in fulfilling optometrists’ role as conscientious primary care practitioners. With anticipated changes in healthcare coming, efficiency will become a premium item.
Objections from patients may include concerns about driving. While there may be impairment among uncorrected presbyopic hyperopic individuals, fitness for driving is generally met following pupillary dilation (Wood et al, 2003; Siderov et al, 2005). You could take the patient’s post-dilation visual acuity for reassurance. Blurring, as we all know, is transient. Glare from bright sunlight is overcome by issuing “mydriatic” spectacles.
And, no, posterior synechiae, as in Figure 1 from a congenital persistent pupillary membrane, are not an impediment to pupillary dilation. CLS
To obtain references for this article, please visit http://www.clspectrum.com/references.asp and click on document #207.
Dr. Semes is a professor of optometry at the UAB School of Optometry. He serves on the advisory board or speakers’ bureau of Alcon, Allergen, Optovue, Med Op, Merck, and B+L.