Fixing Retinal Detachments - Perspective

To place things in perspective, and revisit how we use to fix retinal detachments, let’s begin with an excerpt from the Australian and New Zealand Journal of Ophthalmology. In the article (Banks, CN et al. 1986), a patient recollects his experiences as one of the earliest successful cases of retinal detachment surgery. His story begins when he was 33 years old:

In 1934, when I lived in Genoa, Italy, I had a terrifying experience. One day something like a curtain seemed to split in my right eye; a wall of water descended and shut out my vision. I realized that something extremely serious had happened and went to see a doctor. However, it was obvious that the man did not understand what happened and was unable to help. Thereupon I went to see an eye specialist who told me I had suffered a total detachment of the retina. When I asked him what could be done about it, he said that it could be treated by injecting salt water into the eye and in fact made one such injection.

This fellow’s presenting symptoms, the “curtain” and “wall of water” that “split” and “shut out (his) vision,” are typical of retinal detachments which are commonly associated with partial or complete visual field loss, often acute but sometimes progressive in onset. Back then, the pathologic cause of retinal detachments - retinal tears that developed from the natural separation and pulling of the vitreous humor on the retina – had only recently been elucidated and still remained neither widely known nor accepted. Injecting salt water would have done very little to repair the retinal breaks, but it was a widely accepted treatment for retinal detachments at the time. The patient’s travels and travails continue:

Meanwhile, I received a letter from my parents in Vienna telling me to come to Vienna immediately. There I went to Professor Meller’s Eye Clinic at the Allgemeine Krankenhaus and was seen and admitted to the hospital by Professor Meller’s Assistant, Dr. Urbanek . . . The treatment started with my having to lay in bed for a few days with my head between two sandbags in order to give the detached retina a chance to settle again in its place. Then came the operation, about which I do not know much, expect that it was done under local anaesthetic, that the liquid was drained from the eye and that a needle or needles connected to an electric battery were used. . . During the operating I remember seeing my eye lying on a kind of spoon which was a frightening experience. . . After that came a period of six weeks during which I had to lay in bed motionless with my head between two sandbags which was a terrible ordeal. Then I was allowed to get up and move about wearing what they called a Lochbrille, that is, a pair of dark glasses with only a small hole in the centre of the lenses, the idea being to avoid movement of the eye as much has possible.

The simple sequence the patient describes here, the drainage of accumulated fluid beneath the detached retina and the cauterization or closure of the retinal breaks, constitutes the principal elements of retinal detachment surgery. In the modern era, the cauterization of retinal breaks is performed with lasers or cryotherapy, but in the past it was done by direct needle cautery. The “eye lying on a spoon” likely refers to the use of a speculum or retractors to spread open the lids and retract the extraocular tissues in order to gain access to the eye wall for the actual procedure. The eye itself is never physically removed from the orbit during retinal surgery. Curiously though, judging by the number of times I am asked the question by patients, this perception of the eye having to be removed for surgery remains common even today. Preoperative and postoperative restrictions were more prohibitive back then, and the patient accurately describes the typical sandbag positioning and bed rest which were standard well into the middle of the 20th century for most surgeries involving the eye. The article and patient’s history continue with an account of recurrent retinal detachments requiring multiple surgical interventions over the next decade. In the end, he still ends up near completely blind and dependent on his wife for most of his activities of daily living.

Thankfully, retinal detachment surgery has evolved greatly in the modern age, and we'll explore some of those techniques in future blogs.

Flashes & Floaters

Well it's been a while since my last post, but we'll return to the issue of retinal detachments here. Detachments generally occur from breaks in the retina, the neurosensory tissue that lines the back of our eye and is responsible for cpaturing the visual image. A retinal break occurs from a tractional, or pulling, force exerted upon the retina by the vitreous humor, the gelatinous substance that fills the back of our eye and lines our retina.

Certain individuals are at particular risk of developing retinal breaks - namely those who are nearsighted, have a family history of retinal detachments, a past history of head or eye trauma or eye surgery, and those with systemic medical disorders affecting the structural tissues that form the eye and vitreous humor. Retinal detachments are more common in men, and race, too, is a proven determinant. Asians and Indians have a higher frequency of retinal detachments, vice versa for those of African descent.

But detachments can occur in everyday normal sighted individuals as well, simply from having too many birthdays. As we age so does our vitreous humor. When we were not yet born, the vitreous was a dynamic biological structure filled with vessels that nourished and helped develop the eye. Yet, by the time we entered this world, the blood vessels had regressed and all that was left of the vitreous was a clear matrix consisting of strands of collagen (a structural protein) held together by sugar molecules. In a young eye, the vitreous fills the back and firmly adheres to the retina. As time passes, though, the sugar linkages begin to break down and liquefied pools of fluid begin to form within the vitreous, a phenomenon called vitreous syneresis. This is what gives us floaters, or the little particles of debris that float around in our eye. This process of liquefaction eventually reaches a critical state, just when that occurs varies but the incidence typically increases in the fifth and sixth decades of life, and the vitreous humor separates entirely from its posterior and peripheral connections to the retina. Called a vitreous separation or vitreous detachment, such an event is often accompanied by flashes and a sudden increase in floaters. In most cases, the process is benign and the flashes and floaters dissipate over time as the vitreous humor continues to liquefy, but in some a retinal tear may occur in areas of abnormal vitreoretinal traction. When a retinal break is present, liquefied vitreous can pass through the defect into the subretinal space resulting in elevation and detachment of the retina.

Well, just how common are retinal tears and detachments? Tears are found in up to 1/10th of the population but detachments occur less frequently, at an incidence of approximately one in every 10,000 individuals. From this we can gather that the majority of retinal breaks, fortunately, do not lead to retinal detachments. Still, because retinal detachments are significantly harder to treat than tears, it befits patients to have any potential tears properly assessed and treated before they might become more serious concerns. If a tear is found, it can be treated right away before it becomes a detachment. That is why anytime someone experiences flashes or floaters or loss of their visual field, even if it might just be a benign change of the vitreous humor, it's important you call you eye doctor and have a thorough dilated eye exam.

Electric Light Baths, Sandbags, & Retinal Detachments

A century ago, if you were so unfortunate as to have developed a retinal detachment, the likelihood of having your retina reattached, much less retaining any vision at all, was slim to none. A 1912 survey by Derrick Vail, Sr., a founding member and president of the American Academy of Ophthalmology and Otolaryngology, queried American ophthalmologists regarding their knowledge of successful retinal detachment outcomes. Near three hundred ophthalmologists responded and only 20 successful cases in their total cumulative experiences could be documented. With these figures, the incidence of successful retinal detachment outcomes was estimated at about one in every thousand, small hope indeed. Of course, one can appreciate why this might have been the case when they consider common therapy for retinal detachments in the era included medically induced sweats, electric light baths, sandbags, or simply months of bed rest. Fast-forwarding to the modern age, detachment surgery success rates are now well over 90%, and a number of techniques are presently available to achieve favorable outcomes and the recovery of meaningful vision. Now, most of us don’t give much thought to our likelihood of success after retinal detachment surgery, if any time is dedicated to the consideration of retinal detachments at all, so it’s difficult to appreciate these numbers, but modern retinal detachment surgery is truly one of the great achievements of 20th century medicine and surgery. We'll consider retinal detachments and how they come about in more details in my upcoming posts.

Voodoo & the Evil Eye

This past Saturday I was invited to speak to the local meeting of the Barbados Society of Central Florida. I'd spoken to them before on diabetes and I thought retinal detachments might be an interesting and important subject, but I threw in a little bit about voodoo magic as well.

Most of don't give much serious thought to voodoo, but there are mechanisms by which it can really cause disease. Years ago, I had a suggestible young fellow from Jamaica as a patient who believed his wife was hexing him. Supposedly, she had placed a hex on him which would make him blind, and shrotly thereafter he began to notice symptoms in his right eye. Well, lo and behold, when I examined him he really did have a retinal detachment, a type called central serous retinopathy which can be seen in individuals under stressful situations. But was it voodoo?

Certainly, common sense would have us believe otherwise and no physician would admit to a direct relationship between disease and curses, in this case voodoo, but an indirect connection has been recognized for years. We've all heard stories of voodoo death. Just stories right? Well, that’s what you’d like to believe.

Back in World War I, physicians were witness to peculiar cases of soldiers dying on the battlefields of the Western Front. These traumatized soldiers hadn’t suffered any mortal wounds but they inexplicably died of shock, a medical disorder normally brought on by a critical drop in blood pressure from excessive bleeding. Some of these same physicians later became familiar with cases of supposed voodoo death, and they recognized a connection with the soldiers. They suggested that, just like individuals morbidly terrified by a magic spell, the soldiers suffered from an over stimulation of the nervous system which led to a form of fatal shock. Fear, in other words, stimulated the nervous system to such a degree that the excessive release of tremendously potent biological hormones caused vital hemostatic alterations and, in those susceptible, death.

Voodoo, essentially, is the sinister opposite of the placebo response, whereby a patient’s belief that a medicine will work, even if no actual medication is administered, results in improvement of a medical condition – a phenomenon well documented in medicine. In voodoo and related phenomena, individuals believe that something bad will happen to them and, even if there is no physical stimulus, it does. So, in this fellows case, and that of central serous retinopathy, acute stress likely induces a similar, but more locally acting, hormonal imbalance that alters the hemodynamics of the retina and result in a retinal detachment with vision loss. My patient's detachment eventually resovled as he came to grip with his stresses - as you can imagine he was in a very difficult marriage - and in the end, there really was some truth to voodoo magic in this old wife’s tale – evil eye and all.

Diabetes & Brain Surgery

I posted this article here because it is a striking reminder of how far we have come in the treatment of diabetes. Just a few decades ago, articles were being published that seriously suggested brain surgery as a treatment for diabetic retinal disease. In this 1968 issue alone of the Journal of the American Medical Association, three separate papers reported on the beneficial role of surgical removal or radioactive ablation of the pituitary gland (the part of our brain that controls hormone production) for severe cases of diabetic retinopathy. At the time, medical thinking held that certain hormones released by the pituitary gland may make the disease worse, and, in what now seems a less than brilliant leap of deduction, some reasoned the pituitary gland must go. So not more than three decades ago, you might not only have lost your vision from diabetes but your mind as well.

Fortunately, a generation of astute physicians recognized that patients who had diabetes and at the same time certain other retinal diseases that naturally damaged the peripheral retina, such as syphilitic retinitis, rarely developed the complications of diabetic retinopathy. This was because the concomitant retinal diseases had already wiped out the areas subject to severe ischemia in diabetic retinopathy. Like Einstein, physicians made their own quantum leap – without the ischemic stimulus, diabetic retinopathy did not seem to progress into its advanced stages. If only they could treat or cauterize the ischemic retina that develops in diabetes then they might be able to slow down the progression of disease. Meanwhile, they could also cauterize any leaking blood vessels present in order to decrease retinal swelling. All of this might prevent the severe loss of vision that was, up until then, part and parcel of diabetes. Well reasoned indeed but what was missing was a safe and effective tool by which these outcomes might be achieved – and we all now know that turned out to be the laser.

Einstein and Lasers

Albert Einstein conceived the principles of the laser nearly a century ago. Though many would argue his greatest contribution to science remains the theory of relativity, Einstein did not receive the Nobel Prize for that body of work. He did receive it, though, for his work on the photoelectric effect. For decades, scientists had observed and wondered why electrons were emitted when light shines on a metal surface. In a 1905 paper, Einstein demonstrated how matter could absorb and emit light energy, the energy of photons, and he provided a theoretical explanation for the photoelectric effect. That work would form the basis of Einstein’s 1917 paper where he proposed that a photon of energy, or light, might be emitted by excited atoms - the laser effect.

Today, the treatment of diabetic retinopathy to prevent blindness is one of the leading applications of lasers in ophthalmology. Just half a century ago, a diagnosis of diabetic retinopathy meant you would probably end up blind. It was just a matter of when. Due to lasers alone, diabetic retinal disease, and for that matter a number of retinal and ophthalmic conditions such as retinal tears, detachments, tumors, and glaucoma, are no longer the threat to eyesight they once were. The laser has truly been a remarkable vision of science and ophthalmologists continue to explore new possibilities for its use even today.

When a patient with diabetic retinopathy presents with loss of vision, lasers can be very helpful in recovering lost vision and minimizing the progression of disease. Depending on the extent and type of treatment required, an anesthetic shot and multiple treatment sessions may be necessary. The treatment is often done right in the doctor's office, takes no more than 15-20 minutes and you can go home the same day - and if the patient takes good care of their blood sugars and health, it has a very good chance of limiting disease progression

The intellectual quest that led to the realization of Einstein's seminal 1917 thesis in the laser and its subsequent application in the treatment of eye diseases makes for one of the truly remarkable stories of the 20th century and modern medicine . . . but that's a story for another blog.

Diabetic Retinopathy

Today, diabetic retinopathy remains the leading cause of legal blindness amongst working-age Americans. An estimated 29 million Americans age 20 years or older have either diagnosed diabetes, undiagnosed diabetes, or impaired fasting blood glucose levels. One third of individuals are unaware they even have the disease. The hormone in our body that controls the metabolism of sugar is insulin. In diabetics, insulin is either produced in insufficient quantity or does not function properly upon its target tissues. As a result, abnormal sugar by-products accumulate throughout our body with damaging effects. The longer one has diabetes the more likely they are to develop its complications, and, as previously mentioned, one of the more commonly affected tissues is the retina. Diabetic retinopathy can be one of the most debilitating aspects of long standing diabetic disease. In patients lacking resources, or those who have not been able to control their disease or receive timely treatment, blindness from diabetes still occurs.

As mentioned, the complications of diabetes result from the effects of abnormal blood sugar metabolism on our body, particularly wherever it has small blood vessels. As the duration and extent of diabetic disease grows, especially in light of poor control, these blood vessels become incompetent. Retinal vessels in particular can become abnormally dilated with the tendency to leak fluid, and this results in swelling of the retina, known as macular edema, with the resultant loss of vision. Alternatively, the retinal vessels can close off completely causing ischemia - a lack of oxygen and nutrient perfusion. Ischemia leads to the development of abnormal new blood vessels which have a tendency to bleed and form scar tissue, and these in turn can cause retinal detachments and even total blindness.

First, take a look at this normal retina, you'll see the normal blood vessels with their branches, the orange appearing retinal tissue, and the optic nerve, the yellow circle which carries the visual signal from the retina to the brain.

Figure Coutesy of the National Eye Institute, National Institutes of Health

Now have have a look at this video. What you see here is actually a fluorescein angiogram of a patient with diabetic retinopathy. An angiogram is a sequence of pictures, in this case a movie, of the retina taken after a fluorescent dye is injected in to the patient's blood stream. If you look closely, you'll see the normal large blood vessels of the retina fill as the dye passes int to the retina's circulation but, more importantly, you'll begin to see it leak out of microaneurysms (the tiny little dots) and abnormal neovascular blood vessels. Leakage from microaneursysms causes macular edema and leakage from neovascular blood vessels causes vitreous hemorrhage, or bleeding (in this case, demonstrated by dark shadows obscuring the retina). This patient has both.