Treatment of posterior segment disease is in the midst of a paradigm shift, says a panel of experts at this year's annual SECO 2017 conference in Atlanta.
Atlanta-Treatment of posterior segment disease is in the midst of a paradigm shift, says a panel of experts at this year's annual SECO 2017 conference in Atlanta.
New options are changing the way optometrists examine retinal care without the need for invasive surgery, and it's all thanks to an explosion of interest in retina studies over the past decade.
One challenge facing retinal optometry lies in understanding the underlying causes behind macular edema in retinal vein occlusion.
The mechanisms are still not well-known, but there is a visible path for how research in the field needs to proceed, says panelist John Randolph, MD.
Vein occlusions are not one disease but fall into three categories:
• Combined vein and artery occlusion
• VEGF driven
• Inflammatory mediator driven
Although drug therapies exist to help manage these varying types of occlusions, patients must undergo frequent treatments. Fortunately, many of the delivery systems used in these therapies are improving, Dr. Randolph says.
“We’re hopeful that, instead of these patients coming in every four to six weeks, they’re going to start coming in every three to four months,” he says.
Alongside the traditional steroidal and anti-inflammatory drug therapies, anti-EPO therapy is a becoming a possibility for managing retinal care in a different way.
“We’re finding that EPO is present in every type of edema,” he says. “It may be a critical pathway that we can block.”
Perhaps one of the most frightening situations for a patient to deal with is retinal detachment.
Addressing the complex challenges optometrists encounter when facing retinal detachment cases, Dr. Randolph says a primary challenge lies in just how difficult it is to examine the peripheral retina. Although visual tests have taken the guesswork out of macular diagnosis, the peripheral retina still relies on how skilled each practitioner is at assessment.
Retinal detachments are typically a meshwork of many different retinal concerns, usually falling into three categories:
• Serous retinal detachments
• Traction retinal detachments
When diagnosing these conditions, Dr. Randolph advises doctors to be careful with their verbiage during patient consultations, particularly when describing relatively benign conditions such as vitreal detachments.
“When they hear detachment, they don’t hear anything else you say afterward,” he says.
When correcting for rhegmatogenous detachments, optometrists have several treatment options.
• Pneumatic retinopexy
• Scleral buckle
Each of these has its own side effects and benefits, and Dr. Randolph stressed that optometrists should get as much information as possible before making decisions-particularly when macular concerns are suspected.
“It’s always a good idea to get an OCT of the macula just to document the status because at the end of the day, after the detachment is fixed, the recovery and the final vision is solely based on whether the macula is involved," he says.
Related: Stem cell trial aims to cure AMD
Treatment of retinal degeneration, another important affliction affecting retinal health, is also in its infancy. As of now, the study of macular degeneration is relatively new and optometrists have limited options for managing its symptoms.
“The vision-limiting problems with these disorders are due to atrophy,” panelist Eric Sigler, MD, says.
And atrophy, meaning loss of cells, is not treatable at this point. Because of this, early detection of symptoms and treatment before the damage occurs should be the top priority for optometrists, he says.
Optometrists must educate themselves on recognizing the genetic factors inherent to macular conditions in order to provide better care.
“There are some things that we know are genetically inherited, we know that they have a dominant pattern of inheritance or a recessive pattern of inheritance, and they lead to macular dystrophies,” Dr. Sigler says.
Although assessment strategies such as fluorescein angiography are helpful for detecting macular problems, these established strategies aren’t the only tools available to optometrists.
Dr. Sigler noted the importance of OCT angiographies and OCT Dopplers for future macular assessments. These two modalities are able to give optometrists more information about possible choroidal neovascularization in macular tissue as well as essential data about the blood vessels in the retina.
“If we can identify high-risk anatomy prior to the development of exudation and decreased vision, then we can start preventing vision loss,” he says.
When it comes to age-related macular degenerations, genetics and stem cells are frequently invoked as the future of patient care. Despite this, the treatment potential of stem cells is not well understood by most practitioners, Dr. Sigler says.
The key for patients with genetic disorders is finding them early, but many symptoms don't show up until late stages of the disease. The biggest frustration comes from patients who have dry age-related macular degeneration (AMD) and experience advanced geographic atrophy, in which the pigmented layer of the retina - the retinal pigment epithelium (RPE) retina - is atrophic.
Late detection presents a big frustration for practitioners, who are often left with few, if any, treatment options.
While genetic testing may one day provide an early detection solution, right now it’s not clear what gene leads to what abnormality nor how much environmental factors affect the disease, Dr. Sigler says. Smoking and obesity have been shown to play important roles, but many other factors could be at play.
One promising development comes from the second formula released by the ongoing age-related eye disease study sponsored by the National Institutes of Health (NIH), AREDS 2. Findings point to a 25 percent reduction in risk of progression from intermediate AMD to advanced AMD, but the risk reduction doesn't show up until after about four to five years of active medication.
Of course, gene therapy has its risks and limitations, Dr. Sigler says. Patients often respond well to the idea of stem cell therapy, but the problem is that the damaged cells themselves aren't being replaced. Injecting stem cells into damaged areas can lead to poor results, and the therapy is still several years off, he says.