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Undilated retinal evaluation possible with high-magnification fundus lenses
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While practitioners agree that, ideally, pupil dilation is the best way to provide a funduscopic evaluation of the retina, unfortunately, some patients will resist it.
“The reality of practice is that you can’t dilate everybody,” said John A. McCall Jr., OD, a private practitioner in Crockett, Texas. “If you have a hyperopic patient, you know you’re going to blur the vision if you dilate him or her. Under certain driving conditions, you’ve basically crippled the patient, and some patients absolutely have to get back to work. The dilemma is how to examine the fundus and provide standard of care without dilating.”
Dr. McCall and some of his colleagues have found satisfactory solutions to this problem, although they emphasize that these methods are not substitutes for dilation.
“It is always better to dilate – always,” said William Jones, OD, practitioner from Albuquerque, N.M. “However, if a patient refuses to be dilated for any reason, there is an option, once a practitioner becomes adept at it.”
The 90-D lens
Dr. McCall previously used monocular indirect and direct ophthalmoscopes and once tried a product called a micro-pupil lens, or small pupil lens. After much experience, he has found that the Volk 90-D lens consistently provides the best view of the fundus through an undilated pupil. “You have to use a small slit, so you get a slit-view of the fundus,” he said. “It’s a magnified, stereoptic view.”
On a patient with an average-sized pupil, Dr. McCall said, he can go from mid-periphery to mid-periphery, all the way around. “You get a gorgeous view of the entire posterior pole, the optic nerve and a stereoptic view of the cupping, which is extremely important,” he said.
Dr. McCall said he did not personally develop this technique; it was originally intended to complement a dilated fundus exam. He said it took time to hone his skills at this approach. “There is a learning curve; it takes practice,” he said. “My advice to practitioners would be to not give up after a few patients. You need to use this on about 100 patients to build your confidence.”
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Dr. McCall maintains that he continues to dilate whenever it is reasonable to do so. “Most prudent practitioners will dilate every pupil that it is reasonable to dilate,” he said. “Certainly, every first-time patient needs to have a complete dilated fundus exam. You need to know what’s there. Once you have an established patient who you have seen a number of times, then you have a more comfortable feeling about the medical and ocular health of that patient.”
Dr. McCall said diabetic patients need annual dilated fundus exams, and those who have developed retinopathy should be dilated every 3 to 6 months. For glaucoma patients who have already had numerous dilated exams, it may not be necessary to dilate. “The 90-D works wonderfully without having to dilate,” he said. “You want to see the optic nerve and as much of the retina as you can.”
Dr. McCall concluded that every practitioner ultimately learns to use his or her own judgment in matters of dilation. “I think most practitioners have developed their own comfort zones as to when to dilate and when not to dilate,” he said. “Still, I would advocate dilation whenever possible.”
The Super VitreoFundus lens
Dr. Jones has also used the 90-D lens to examine the fundus, but said he has found the Volk Super VitreoFundus lens to be “a little bit better.” This lens is 9.4 mm with a 106.4-D power. “For a patient whose pupil is not too small and who is cooperative in holding his or her position,” he said, “I can actually get out to a posterior vitreous base area, undilated.”
Dr. Jones said he has discovered a wide range of optical anomalies when using both the 90-D lens and the Super VitreoFundus lens. “I have found percolated tears in the far periphery and lattice with or without holes,” he said. “I even found a retinal dialysis, undilated.”
Dr. Jones has also been able, using a video slit lamp, to actually capture images of peripheral lesions undilated. He said a skilled practitioner using the Super VitreoFundus Lens on an undilated pupil will not miss major abnormalities.
“You can be sure that if you use this method you will not miss anything significant, such as a retinal attachment, a large tear of the retina or a tumor,” he said. “You might miss something small out in the periphery. I usually don’t miss anything, but there is always a little risk involved when you don’t dilate.”
Dr. Jones said, as with the 90-D lens, undilated fundus exams with the Super VitreoFundus lens require a good deal of practice. “To do it once a year is probably not a good option,” he said. “If you do this once a day, you would become adept enough to have a lot of confidence that you are getting a good view of the fundus.”
Dr. Jones said his discovery of undilated fundus exams was similar to Dr. McCall’s. “When the 90-D lens first came out, we would always use it on a dilated patient,” he said. “Then one day I wondered if I could see inside the eye undilated. I just wanted to try it, and I found that I got a very good view undilated with the 90-D lens.”
Dr. Jones later discovered the Super VitreoFundus lens. “I found it was even easier to get into an undilated eye with the Super VitreoFundus than with the 90-D,” he said. “I found that I could get beyond the equator and check all of the quadrants, all of the areas of the fundus.”
Dr. Jones agreed that it is a good idea to dilate first-time patients, as well as high myopes, those with retinal problems, those with diabetes, those who have suffered trauma to the eye and symptomatic patients.
However, patients can always refuse dilation, he added – and an undilated exam at least provides basic information. “It is far better to take a look inside someone’s eye,” he said, “even with this undilated option, than to have him or her leave your office without you ever having looked inside at all.”
For Your Information:
- John A. McCall Jr., OD, is a member of the Primary Care Optometry News Editorial Board and practices in Crockett, Texas. He is also senior vice president of vendor relations for Vision Source. He can be reached at 711 East Goliad Ave., Crockett, TX 75835; (936) 544-3763; fax: (936) 544-7894.
- William Jones, OD, is a member of the Primary Care Optometry News Editorial Board and practices at the Eye Institute of Albuquerque in Albuquerque, N.M. He can be reached at 1828 Conestoga, SE, Albuquerque, NM 8712+3; (505) 293-7347; fax: (505) 247-2153.
- Neither Dr. McCall nor Dr. Jones has a direct financial interest in the products mentioned in this article, nor is either a paid consultant for any companies mentioned.
- The Super VitreoFundus Lens and the 90-D lens are available from Volk Optical, 7893 Enterprise Dr., Mentor, OH 44060; (440) 942-6161; (800) 345-8655; Web site: www.volk.com.