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Glaucoma isn’t being treated aggressively enough, and eyecare practitioners are being too cautious when it comes to treating and diagnosing the disease-often at the patient’s expense.
Las Vegas-Glaucoma isn’t being treated aggressively enough, and eyecare practitioners are being too cautious when it comes to treating and diagnosing the disease-often at the patient’s expense. Eric Schmidt, OD, FAAO, in Wilmington, NC, gave the warning at a lecture at Vision Expo West 2016.
Detectable glaucoma has evolved over the years, changing the way optometrists are approaching care. Glaucoma is a silent disease; by the time symptoms are visible, the damage has already been done. Worse yet, the more advanced the disease is, the faster it degenerates vision, leading to eventual blindness.
The problem is one of identification-glaucoma patients must be identified early for treatments to be effective. To accomplish this, optometrists must use cutting-edge research and detection tools to find and begin treating glaucoma early.
“In general, I don’t think eye doctors treat glaucoma aggressively enough,” Dr. Schmidt says. “Glaucoma is not an equal opportunity offender.”
He says that certain individuals are more at risk than others. Regular monitoring through OCTs, visual fields, and gonioscopy is necessary for optometrists to stay on top of patient health, particularly when conflicting data from day to day clouds potential glaucoma diagnoses.
As most practitioners know, deciding how to treat glaucoma isn’t hard-it’s knowing when to consider treatment that is more difficult. Above all else, monitoring progression is key in individuals at risk for glaucoma or who have already been diagnosed with glaucoma.
“Treat early, treat often, and treat aggressively,” says Dr. Schmidt. “I think there are a lot of people who are under diagnosed, and under treated-they’re controlled, but their pressure is too high.”
He recommends the acronym FINDACAR to understand the breadth of variables that may put a patient at risk for glaucoma:
• Family history
• Intraocular pressure (IOP)
• Diabetes and cardiovascular disease
• Corneal thickness
He adds that the more risk factors present, the more susceptible the optic nerve is to damage and the more likely a glaucoma diagnosis.
IOP and serial tonometry
IOP readings are one of the primary ways to detect signs of glaucoma. Although OCTs and visual fields are used to “prove” glaucoma, regular IOP checks are the best way to obtain data on how internal eye pressure fluctuates over time.
Dr. Schmidt highlights the importance of testing during each patient evaluation, noting that overall trends are more important than individual numbers.
“You need to have lots of pressure readings” he says. “The more numbers you get, the more value your data gives you.”
In his view, serial tonometry is critical for understanding a patient’s ocular pressure across each year.
“It’s better to get extended IOP readings on different days, different months, over the course of time,” he says. “The more untreated pressure readings you can acquire, the better your decision making.”
Keep in mind that any single IOP measurement taken between 7 a.m. and 9 p.m. has a higher than 75 percent chance to miss the highest point of the diurnal curve.
“The greater the variability [in IOP] over that person’s life, the more likely they are to progress,” he says.
One of the most important factors that delineate the need for treatment in patients with high pressures is thin corneas.
For every 40 µm thinner a cornea measures, the risk of developing glaucoma increases by 71 percent.
Corneal history is leading risk factor for disease progression because thinner corneas are more susceptible to pressure stress. Corneal thickness via pachymetry is an important measure to determine rate of progression in patients already diagnosed with glaucoma.
Using OCTs and visual fields
Using serial tonometry as a starting point, optometrists rely on OCTs and visual field testing to confirm glaucoma suspicions and monitor progress over time.
According to Dr. Schmidt, OCT is the best way to diagnose glaucoma and the quickest way to detect changes in retinal nerve fiber layers, and both treatments have their place.
“OCTs are more reliable early in the disease,” he says, “but once you make the decision to treat, and the patient has glaucoma, visual fields become very important. Visual fields are subjective measurements of how well the optic nerve is working. It’s a performance-related index.”
Most practitioners perform fewer visual fields less than they should, he says.
Although visual fields are still the standard of care, it’s important to note that if optometrists wait for a glaucoma confirmation from visual field testing alone, it may already be too late. Visual fields should be used to determine progression, rather than the initial diagnosis.
“Multiple pre-treatment readings are needed to make a decision,” Dr. Schmidt says, “and multiple post-treatment readings are needed to make a decision for treatment changes. Also, multiple visual field tests are needed before you decide whether there’s progression.”
Diagnosing glaucoma is one thing, but it isn’t the only step on the path to better health. Patients must be compliant with the therapies recommended by their optometrists.
“Compliance is everything,” says Dr. Schmidt. “You can’t make patients use drops, but we know compliance gets better with the fewer drops we use. We know that compliance improves when, every time patients come in, you talk to them about the importance of their eye drops.”
He stresses the value of keeping patients informed about their condition, including showing them how to use the drops themselves. When patients feel confident in their abilities to manage their own treatments, medication compliance will likely increase.
The everyday OD
At the end of the day, regular monitoring of glaucoma signs and symptoms is still the best way to improve health outcomes for patients.
Glaucoma may be evolving, but it’s still a slow-moving disease. With glaucoma, optometrists don’t follow the individual phenomena, they follow the trends.
Despite the advancements in tonometry and tomography that are giving optometrists more patient data than ever before, the need for long-term testing and evaluation hasn’t changed. Overall goals should be focused on lowering and stabilizing patient IOPs, as well as closely monitoring for changes in patient health through OCT scans, visual field tests, and inter-ocular photography.