Ultra-widefield imaging systems have been widely adopted in optometry, and for very good reasons.

For starters, it is simply excellent at what it can do. Most of the retina can be seen with high resolution. It’s fast and efficient and more comfortable for patients than a dilated retinal exam with a slit lamp and binocular indirect ophthalmoscope.

Furthermore, multiple pictures taken at different times can be compared side-by-side for changes. Finally, some argue that ultra-widefield imaging (UWFI) is better at discovering peripheral lesions than traditional dilated fundus exams. If true, that alone is a big advantage.

We have embraced the technology as well. Our practice has UWFI systems in each of our 17 offices. It provides an excellent documented image of retinal pathology that is being monitored for changes over time. It also allows us to share a picture of an uncertain finding with our colleagues within our practice for their opinions.

However,, even if UWFI is better at detecting peripheral lesions than a dilated exam, all the doctors at PCLI are firm in resisting it as a substitute for a dilated clinical exam. Why?

Ours is a referral center with the overwhelming number of patients seeking a consult for surgery – cataract surgery in particular. While we have the duty to provide an assessment of overall eye health, our primary goal is to answer a very specific question: Does this patient have preexisting risks for a poor outcome or a complication from surgery? If so, they need to be informed and a decision made as to whether to treat that condition prior to surgery or avoid surgery altogether.

To be even more specific, we are most carefully and actively searching for findings that increase risk for either retinal detachment or macular edema. So we need to do our best to find retinal breaks as well as anything else that puts abnormal traction on the retina.

For starters, this means evaluating the posterior segment three-dimensionally, including a careful examination of the vitreous, from front to back, something that – so far – has eluded any two-dimensional photograph focused at the retinal plane. Identifying and documenting a choroidal nevus, a congenital hypertrophy of the retinal pigment epithelium or paving stone degeneration is less critical to cataract surgery outcomes. Determining whether a patient has an intact, partially detached or fully detached vitreous is far more important.

There is no doubt that a preoperative macular OCT has improved the detection of what were previously difficult conditions to detect clinically with ophthalmoscopy, such as a barely detectable epiretinal membrane vessel distortion. These are usually discovered only by a subtle reflective vitreoretinal interface with a careful focus of the slit lamp. While missing these may have little consequence in a primary care exam, they place surgery patients at higher risk for not only postop cystoid macular edema (CME), but chronic CME that can be challenging to successfully treat to resolution.

As of yet, we are unaware of anything superior to a macular exam through a widely dilated pupil with stereopsis and high resolution. How so? For one, the slit lamp illumination can be controlled to give a different appearance to the same finding, through direct and indirect illumination. In addition, the deflection of a thin beam remains one of the most sensitive techniques for identifying abnormal retinal thickening.

In essence, an active dilated examination of the peripheral retina is dynamic, meaning that the examiner not only has control over the size and location of the illumination spot for direct and indirect illumination of a retinal finding but can see its appearance from different angles. Sometimes that means simply having a patient move their eye a little, sometimes it means the examiner changes his or her position.

But the best and most controlled way to dynamically see any spot on the retina is still with scleral depression. It’s impossible to exaggerate how many times we’ve seen a small white spot open into an obvious retinal tear with scleral depression. If we haven’t done all that we can to find any retinal tears, retinal tufts or posterior tractional breaks adjacent to lattice, we haven’t fulfilled our duty. We have to use the best known techniques available.

And while some claim that UWFI is superior at detecting peripheral pathology, there are no definitive studies to support this assertion. Furthermore, the breaks that are most dangerous are found superiorly, where UWFI can’t view. Until UWFI can do a dynamic exam, we’ll stay with active dilated clinical ophthalmoscopy.

There’s one final reason we stick with the dilated clinical exam, one that raises more questions rather than providing a specific answer. Acquiring the skills to become proficient at a dilated retinal exam, and binocular indirect ophthalmoscopy in particular, requires years of experience. The ability to locate everything possible, through pupils of various sizes and cataracts with different densities, is hard enough. But the ability to accurately label what is seen – and consistently diagnose it correctly – takes a lot of experience and many examples. Just how much? We don’t know if anyone can say for sure.

But this we can say with some authority (and humility): Each of the optometrists at Pacific Cataract and Laser Institute performs dozens of dilated examinations every week. We were all trained in school and particularly in residency in advanced binocular indirect skills. We all perform scleral depression, often many times a week. I don’t know any one of us who feels they can’t continue to improve. And if we did a dilated retinal examination only when the symptoms or findings indicated, our skills would erode. How many examinations do we need to do a week to prevent that? We don’t know. Each of us out there is different, some needing more practice than others to stay proficient. But like any complex skill, we know we need to do it a lot to stay minimally competent and even consistent with frequent practice to be sharp.

This can be a slippery slope. When a particular skill erodes from less use, will we avoid it altogether? And then what do we do when the situation requires it, and the clinical presentation is a challenging one?

Perhaps that’s single most important reason we don’t want to rely exclusively on UWFI as a substitute for a dilated exam.

Your opinions and comments are welcome.

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