Being an optometrist can feel a lot like being a detective. A patient presents with reduced vision—and it could be almost anything. Sleuthing out the underlying cause is often what makes our clinic experience so enjoyable and challenging.
The importance of diagnosis is pervasive this month in our 9th Annual Retina Report and part two of our new series, Take Charge of Glaucoma. Here’s a preview.
How to Handle Hemorrhages
All vitreous hemorrhages would require a referral, but the timing is a puzzler that calls for a little detective work to understand what’s at stake. Technology can be a huge help. If you can get a B-scan to ensure the retina is intact, for example, you can more safely monitor the condition.
Here are some insights from my colleague John Kitchens, MD:
If the patient has no history of diabetes, the hemorrhage is likely secondary to a posterior vitreous detachment (PVD), unless trauma or another obvious cause is present.
With a history of diabetes, if the fellow eye has mild nonproliferative diabetic retinopathy (NPDR) and the patient has good glucose control, be more concerned about a PVD or even a horseshoe tear, especially with symptoms of floaters or flashes.
If the patient has severe NPDR, it may be the cause of the hemorrhage.
You should refer any patient who does not have diabetes but presents with a hemorrhage in the macula. The chances of a small branch retinal vein occlusion (BRVO) or early choroidal neovascular membrane (CNVM) are too high to monitor.
Hemorrhages outside of the macula are a different story. A diabetes patient with a large preretinal hemorrhage likely has neovascularization and thus early PDR. If multiple hemorrhages exist in one particular quadrant in a patient without diabetes, think extra-macular BRVO.
With a normal OCT, a referral within two to three weeks is reasonable. If hemorrhages are associated with PVD symptoms, refer as if the patient may have a tear. A patient with a one-to-four disc area subretinal hemorrhage at the equator and drusen or peripheral reticular changes likely has an eccentric CNVM. Refer the case, as these can result in breakthrough vitreous hemorrhage.
The most common scenario when you will not want to send to retina is a single flame-shaped hemorrhage in a patient without diabetes. Call the primary care provider and ask them to order a complete blood count and check blood pressure. See the patient back in a few weeks. And remember: it can take six to eight weeks for the hemorrhage to resolve.
See the (Blue) Light
This is another tricky clinical case, both in terms of its visual effects and how to educate patients properly. Giles Duffield, a PhD at the University of Notre Dame, has dedicated much of his research to circadian rhythms and the effects of blocking blue light. He notes how blue light from digital devices resets the internal clock, so to speak—a major reason why children are not getting enough high-quality sleep. According to Dr. Duffield, the brain perceives a device’s late-day blue light as morning light, creating a jet-lagged effect.
This month’s CE article delves into the details to help you understand blue light’s impact on AMD patients and anyone using digital devices.
Gear Up for Glaucoma
I was managing glaucoma patients quite well 15 years ago—until I started using OCT. It completely changed our understanding and management of the disease and now allows us to make a diagnosis years earlier, preventing vision loss in many patients. Today, OCT technology continues to advance, adding progression analysis and even swept-source scanning. But other technologies, such as corneal hysteresis, are now changing our understanding of glaucoma, too. Like a good detective, the technology looks where others failed to. By measuring the shock absorption capability of the cornea, hysteresis has been shown to be predictive for visual field loss progression in ways superior to central corneal thickness and even intraocular pressure readings.
Optometry is clearly a field where diagnostic technologies do not stand still. With all of these tools and clinical knowledge at your fingertips, you can be both an optometrist and a detective.