A Look At The Latest Advances In Diagnosis And Treatment
Price Kloess, MD performs cataract surgery
Don’t blink. The technologies used in detecting and treating eye disorders are evolving rapidly, and the outlook is for even brighter possibilities ahead.
To offer a first-hand view of how these new tools are being used to help patients with some of the most common eye disorders, Price Kloess, MD, of Alabama Vision Center and Mark Swanson, OZD, MSPH. Director of UAB’s Ocular Disease and Low Vision Service, discuss emerging advances in ophthalmology and optometry.
A New Way Of Seeing
Technical advances in eye care are not only helping patients see better—they are also helping doctors better see what is happening within the eye itself.
Optical Coherence Tomography (OCT) imaging displays high resolution cross-sectional images of the eye and its microstructures. Another remarkable instrument with a Birmingham connection is the Adaptive-optics Scanning-laser Ophthalmoscope (AOSLO). Designed by UAB assistant professor of ophthalmology Yuhua Zhang, PhD, the AOSLO allows extremely fine detailed imaging of the eye at the cellular level for early detection of age-related macular degeneration, diabetic retinopathy and glaucoma.
“When we use this technology, it’s almost like looking at a microscopic section,” Swanson said. You see an image that’s a bit like an MRI, except with the detail you’d get with a microscope. We can see individual layers of the back of the eye and measure the optic nerve to check for developing glaucoma. We can also spot leakage of fluid or blood from vessels growing under the retina to determine how well treatment for macular degeneration and diabetic retinopathy is working.”
“More than half of people over 60 have cataracts developing, and they also occur in younger people.” Kloess said. “Cataract procedures are the most common surgery in the United States. In recent years, implantable lenses that correct both close up and distance vision have allowed some patients to see well without glasses after surgery. However, patients with astigmatism couldn’t take full advantage of this once-in-a-lifetime opportunity. They had to choose either good close up vision or good distance vision and continue to wear glasses at other times.
“Three of the five FDA trials I’m currently involved in are for lenses that also correct different degrees of astigmatism,” Kloess said. “The results I’m seeing look very promising, and I’m hoping the lenses will be approved soon so these patients will also be able to see well without glasses after cataract surgery.”
The other breaking news is the use of lasers in cataract surgery. Eye surgeons in other states are already using them for this procedure, and Alabama eye surgeons are expected to move toward using lasers in cataract surgery soon. Guided laser incisions are more precise. They can cut perfect circles and offer other advantages that should improve outcomes.”
Swanson added, “Cataract surgery is a simple procedure and most patients do well. What we’d like to see next in research is a major breakthrough that would allow us to prevent or slow down cataracts. Our population is aging, and it’s an issue most of us will have to deal with eventually.”
Macular Degeneration and Diabetic Retinopathy
In both wet macular degeneration and diabetic retinopathy, an abnormal growth of blood vessels in the back of the eye can damage vision and lead to blindness as fluid and blood begin to leak from the new vessels. Until recently, little could be done to stop the process. Lasers were used to eliminate the abnormal vessels, but the treatment was destructive and could damage tissue. Now a drug to block the abnormal growth of blood vessels is showing success in halting progression of these disorders.
“Vascular endothelial growth factor, or VegF, works to stop both common causes of blindness,” Swanson said. “It’s a very targeted therapy and has been extremely successful. It doesn’t restore vision, though there have been some reports of improvement. However, it is very effective at stopping the progression of these disorders.”
At present, VegF does have drawbacks that researchers are working to change.
“VegF has been successful, but in its current form it must be injected into the eye,” Kloess said. “The duration of its action is also relatively short, so injections must be done frequently. Researchers are working on topical and oral medications that would offer the same effectiveness in a form that is easier to administer and easier on patients. Still, even in its current form, preventing blindness is a major advance.”
There have also been advances in surgical techniques for cornea transplants.
“DSAEK is a specialized transplant that takes the place of the traditional transplant,” Kloess said. “In this procedure, we don’t take the whole cornea—just the back layer. In some cases, we use the DALK procedure to replace about 95% of the front of the cornea and leave 5%. Both of these techniques seem to be working better for our transplant patients.”
Medications for glaucoma are getting better, and so are surgeries and monitoring.
“What I’d like to see next is new forms of medication that could be used once a day to improve compliance,” Koss said. “Most people can be consistent with remembering medication if they only have to do it once at the same time every day. When they need to do it several times a day, they can forget or life gets in the way and they get off schedule. When they skip doses, they don’t get the results they should be getting. A once-a-day medication would make a difference.”
“Dry eyes can be part of aging, autoimmune diseases or allergies,” Swanson said. “It should be evaluated to prevent not only discomfort, but also irritation of eye tissue.”
Kloess added, “Dry eye problems are very common in older patients and in certain chronic illnesses. Sometimes the cause is unknown. The emerging strategy for dry eye treatment is not just to prescribe eye drops to add moisture, but to use a secretagogue to stimulate tear production.”
Lasik laser surgery has made glasses a thing of the past for many patients. As the technology progresses, the procedure is becoming available to a wider range of people who might not have been good candidates for it in the past. Now, advances in implantable lenses are offering an alternative to those who may not be good candidates for Lasik or who may have other eye conditions to consider.
“We now have bifocal implants for presbyopia and implantable contacts that correct myopia and distance vision,” Kloess said. “Patients never have to put in contacts or find their glasses again.”
“We’re on the edge of a huge change in the way we treat diseases,” Swanson said. “Instead of a shotgun approach to cure a problem, we’re targeting individual pathways. VegF in treating macular degeneration is one example. It’s very specific and targeted.”
Kloess agrees that major advances from pharmacology research are ahead, and he foresees the not-so-distant day when implantable cameras will give blind people at least a degree of sight to distinguish gross objects.
Swanson summed up by saying, “We’re at the cusp of a whole new way of treating health disorders from a molecular approach. We’re learning so much so quickly. In the past there was always what we called a “Death Valley,” or a long lag between discovery and making new knowledge available in clinical use. The NIH and researchers are now pushing the translation of basic science from the lab to clinical use. We’re working to speed up the process to bring the benefits of new advance to patients.”