In this edition, we will explore and provide you insight into a wide range of ophthalmology topics. We will start at the front of the eye, the cornea, then delve deeper to discuss the lens and ciliary body. Lastly we’ll finish our eye edition focused on the back of the eye, the retina.
Hold tight onto this issue, as we will give you a whirlwind tour of these wide-ranging and fascinating topics that have meaning for all of us, not just our patients. After all, if you live a long life, you will invariably develop one of these problems.
We will discuss the latest and most exciting developments when it comes to refractive surgery, which gives individuals the opportunity to reduce their dependency on glasses or contact lenses. We’ve come a long way since radial keratotomy (RK) surgery of the 1980s. With the advent of newer techniques like laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK), we now have procedures that permit more consistent, predictable and sustained results.
This field is burgeoning, and the population of people that may be good candidates for some type of refractive procedure is enlarging. Even solutions for presbyopia, or farsightedness caused by loss of elasticity of the lens of the eye that compels most of us over age 40 to turn to reading glasses, is being addressed with surgical options. The future may even be more promising and is likely to surpass the vision correction results that we obtain with LASIK and PRK.
Did you know that 3 million people in the U.S. have glaucoma and that this blinding eye disease progresses insidiously because there are usually no symptoms?? Did you know you can have glaucoma but have normal pressure?
Increased pressure in the eye leads to blindness, and eye drops are usually the first line of treatment. New drug classes, each with a unique mechanism, has led to a diversity of eye drop options that we have used for the past 3 decades without any big developments. However there is a new drug class awaiting FDA approval which you can read more about in this issue.
Compliance has been a major obstacle in treating glaucoma patients with drops. Innovative sustained drug delivery devices may lead to improved outcomes, and these are addressed.
For those in whom drops are not enough, laser therapy remains effective to increase outflow or decrease inflow, but there have not been new big breakthroughs here. A momentous advance in glaucoma treatment has been the discovery that cataract surgery lowers pressure. This has been very good news for glaucoma patients as that can sometimes be enough of a drop in pressure to make a difference.
If that is not thought to be enough pressure reduction, then the opening of the eye during cataract surgery now affords the opportunity to insert micro-incisional devices to facilitate the drainage of fluid out of the eye. Our authors have been involved in their development. Additional novel approaches in this micro-incisional surgery arena will be highlighted.
More advanced glaucoma damage requires larger scale, macro surgery. These procedures create a pathway – essentially a hole – from inside the eye to a bleb (a fluid-filled bump) on the ocular surface, and they can achieve profound pressure reduction. Alternate fluid pathways procedures continue to evolve year by year now. If patients undergo frequent eye exams as they grow older as recommended and when necessary, and we use the aforementioned treatments, we can hopefully prevent blindness from this terrible disease.
A cataract is formed as the lens of the eye becomes dense and opacified with age. Less light is able to enter the eye, causing diminished light perception, dulling of colors and blurry vision. Light becomes diffracted, resulting in glare. As the No. 1 cause of reversible vision loss worldwide, a great deal of time and effort has been spent on developing a safe, efficient and accurate surgical treatment.
The evolution of cataract surgery to become the operation it is today is one of the most interesting stories in all of medicine, and that journey is what the authors will share with you, taking you from ancient couching to incisional surgery where the entire cataract was removed.
The invention of intraocular implants allowed the “Coke bottle” glasses of your great grandparents to disappear. Techniques advanced allowing partial removal of the lens. Then ultrasonic dissolution and aspiration evolved to permit smaller and smaller incisions.
Very recently, a unique laser has enhanced and “simplified” the surgical technique whereby the laser can make precise computer-designed incisions and dissolve the cataract. Incision size can be as small as 2mm (less than 1/10 inch), still large enough to remove the old cataract and insert a foldable lens implant substitute. Anesthesia has evolved from required general anesthesia to retrobulbar shots and now simply topical. That makes it infinitely safer for all patients.
While risks of surgery exist, this surgery offers very high levels of postoperative satisfaction. Astigmatism-correcting intraocular lenses (IOLs), refractive multifocal IOLs and presbyopia-correcting ones are available. Models have improved rapidly particularly over the past decade, and there is an excellent chance of finding a precise internal vision correction that makes the patient much less eyeglass-dependent. Essentially, a patient with healthy retina can request and choose crisp near vision or crisp distance vision. If that is not the desired endpoint, then there are multifocal IOL options that try to achieve a hybrid of both. The authors explain how cataract surgery of 2017 should preserve one’s active lifestyles like never before.
Diabetic retinopathy (DR) affects nearly one-third of all patients, and diabetes is the leading cause of blindness in our working-age population. This disease is epidemic, particularly here in Georgia.
A retina specialist will provide you with a succinct understanding of how this condition is managed. He emphasizes how all of us need to work collectively to get our patients motivated to not only achieve good A1c levels, but to address the other factors that accelerate this disease, particularly hyperlipidemia, hypertension and tobacco use.
All of us now know that what was considered an acceptable A1c of 8 in the past is not acceptable and the postponement of nephropathy, neuropathy and retinopathy depend on true tight control. Today he will report that compliant patients seldom end up blind, thanks to more tools in the retinal surgical tool box (small gauge surgery, improved pre-op pharmacology).
I recall during my fellowship and will never forget that one of my friends, in the midst of his neuroradiology fellowship, developed Type I diabetes mellitus. He diagnosed himself. It was ironic that he came down with this, given that his father, a professor of endocrinology, was also the president of the American Diabetes Association. Initially, he went into a deep depression concerned that he ultimately would lose the ability to read X-rays and catastrophizing how his life was doomed. Today such thinking hopefully is truly a thing of the past.
Age-related macular degeneration (AMD) is a very big deal because the aggressive forms of the disease lead to legal blindness (20/200 vision). This represents a severe handicap to our aging population who will lose the ability to drive, read or recognize faces.
Unless you are a pediatrician, you will encounter these visually handicapped patients. Now over 9 million people here in the U.S. have AMD, but 18 million people will have this condition by 2050. That is staggering! Knowing that QALY surveys find that people would rather have AIDS or advanced congestive heart failure than face the prospect of blindness, I am pleased to report that we have made great strides in managing this horrific condition, and a retinal specialist will share the good news with you and what we hope to achieve tomorrow.
No longer are ophthalmologists serving like psychiatrists trying to help these patients cope with their depression that such visual loss brings. Intravitreal injections of anti-VEGF drugs remain the standard of care for wet AMD. Yes, shots directly into the eye. Ninety percent of patients benefit, and of those, almost half experience some vision improvement. Considering 10 years ago when we relied on laser, we could only help 10 percent of patients, this is a revolutionary breakthrough. However, there is still room for improvement in AMD treatments since only the minority of patients experience significant visual gains and the treatment burden of frequent injections is high.
Breakthroughs for patients blinded by retinitis pigmentosa (RP) may include a retinal prosthetic device akin to a cochlear implant, called the Argus. In a different direction, we soon may be able to repopulate compromised/degenerated retinal cells using stem cell replacement, injected under the retina. 3-D printers using living cells placed on a substrate may even build networks of retinal cells that mimic the complex retinal hierarchal structure. Gene therapy provided by a viral vector (adeno-associated virus) has been recently used successfully in Leber’s Congenital Amaurosis (LCA), a blinding eye disease of children, and now may be modified to insert enhanced cells that may suppress natural VEGF production and allow our body to better defend against the onset of wet AMD.
As a consequence of the human genome project, each day more single-nucleotide polymorphisms (SNPs) of DNA are being investigated to find their relationship to eye disease. These discoveries will allow us to explore how we can synthesize protein inhibitors or promoters to prevent or cure disease.
Such research is robustly underway, including biotech company Spark Therapeutics, which is screening large populations to attack some rarer but devastating blinding eye disease such as choroideremia, RP and LCA. Enjoy the this eye edition.