Preface:
I wrote the original draft of this to help my patients with Fuchs’ Endothelial Dystrophy better understand their disease and their therapeutic options. In 2018, one of my patients asked whether I’d be willing to publish it publicly on the Cornea Dystrophy Foundation website. It took some convincing from Bob Bellizzi, but I eventually acquiesced, with the caveat that I could include a preface.
The word “doctor” is derived from the Latin word “docco,” which means “to teach.” I strive to teach my Fuchs’ patients about their condition because it helps me take better care of them: it alleviates anxieties about the unknown and provides a foundation for well-informed decisions. I felt unable to sufficiently educate my patients about Fuchs’ within the confines of a short office consultation, so I wrote this manuscript for them to review prior to and after their visit.
As a patient-centered piece of writing, this manuscript is, by design, not scientifically rigorous. There are a number of generalizations and implicit assumptions made in my writing that are as much a reflection of my own opinion and perspectives as they are a reflection of scientific facts. The manuscript is also not a comprehensive review of every last detail of Fuchs’ Endothelial Dystrophy and corneal transplant surgery; I have focused on what I want my patients to understand and have excluded issues that I feel are less relevant to their care.
Please remember that this manuscript is one physician’s attempt to introduce what I feel are the most important points to know about Fuchs’ Endothelial Dystrophy. I wrote it to serve as a starting point for an ongoing conversation between me and my patients. I hope that my writing helps start the conversation between you and your doctor(s), too.
What is Fuchs’ Dystrophy?
Fuchs’ (fooks) Endothelial Dystrophy is a slowly progressive corneal disease that causes the inside of your cornea to become bumpy and eventually causes your cornea to become swollen, cloudy, and painful. The cornea is the clear, dome-shaped tissue that lives in front of the iris, the colored part of your eye.
Fuchs’ is a problem that affects the corneal endothelium, the innermost layer of cells in the cornea. The endothelium is a single layer of specialized cells. Normal individuals are born with about 4,000 endothelial cells per square millimeter; as endothelial cells slowly die off over the course of a lifetime, the number of cells per square millimeter decreases. By 85 years of age, the number of endothelial cells per square millimeter has decreased to about 2,000 in most individuals. Once endothelial cells die, they do not come back. Healthy endothelial cells interlock with each other like hexagonal bricks on a sidewalk to form a smooth surface on the inside of your cornea. Each cell also functions like a water pump to remove excess fluid from the rest of the cornea. The combined pumping action of thousands of endothelial cells keeps the cornea clear by fighting the cornea’s sponge-like tendency to absorb nutrient rich fluid from inside of the eye. Without functioning endothelial cells, the cornea becomes swollen with the fluid that it naturally absorbs to nourish itself. Endothelial cells in individuals with Fuchs’ die off faster and at a younger age than in normal individuals, but loss of endothelial cells is not the initial cause of vision loss in Fuchs’.
How does Fuchs’ Dystrophy Affect Vision?
Endothelial cells in individuals with Fuchs’ are intermixed with abnormal cobblestone-like bumps that disrupt the smooth inner surface of the cornea. These abnormal bumps are referred to as guttata. The formation of an increasing number of guttata in the center of the cornea, where they have the greatest effect on vision, is a hallmark of Fuchs’. A moderate to severe concentration of guttata can blur vision, reduce black and white contrast, and make colors less vibrant. This is because guttata cause light to scatter in a manner that is similar to the frosted surface manufactured on glass shower doors for privacy. The scattering of light caused by guttata also results in symptoms of glare, halo, and starbursts when viewing bright sources of light, such as when driving at night against oncoming traffic. Blurry vision, difficulty seeing when the lighting is very bright, and a reduction in the quality of vision —all caused by corneal guttata— make up the first phase of disease progression of Fuchs’.
Fuchs’ patients eventually lose enough endothelial cells that there is not sufficient pumping action to oppose the cornea’s natural tendency to absorb fluid. The result is swelling of the cornea, which causes your vision to be blurry. In its early stages, corneal swelling blurs your vision in the morning but not as much in the evening. This pattern is because excess fluid in the cornea evaporates into the air when your eyes are open during the day. Over time, corneal swelling worsens to the point that your vision remains blurry all day, even after your eyes have been open for hours. Blurry vision caused by corneal swelling makes up the second phase of disease progression of Fuchs’.
Severe corneal swelling causes the front surface of the cornea to become blistered and painful. Prolonged blistering of the front surface of the cornea can slowly cause irreversible scarring. Scarring further blurs your vision to different degrees. Severe scars blur vision more than mild scars. Painful blistering of the cornea and scarring caused by longstanding corneal swelling make up the final phase of disease progression of Fuchs’ for most patients.
Is Fuchs’ Dystrophy inherited?
Fuchs’ Dystrophy can be inherited, but not always. Family members can often be affected, although sometimes not at all. It is reasonable to have your immediate family examined to detect the disease as early as possible, but this is a personal decision. A number of medical centers in the United States specialize in the genetics of Fuchs’ Dystrophy, including the University of California San Diego, the University of California Los Angeles, the University of Texas Southwestern, the Mayo Clinic, Harvard, and others.
The genetic cause of the disease is complex —there are many genetic abnormalities thought to be responsible for Fuchs’ dystrophy, including unknown genetic mutations. There are also variations in Fuchs’ dystrophy thought to be related to different genetic causes of the disease. For example, the condition seems to be distinctly different in certain parts of Asia compared to the United States.
Is Fuchs’ Dystrophy an emergency?
Fuchs’ Dystrophy can be a distressing diagnosis but, thankfully, it is not a medical emergency. Most individuals with Fuchs’ are unaware that they have the condition until they are about 40-50 years of age. This is because the disease does not typically interfere with visual function in the first few decades of life and because it can be difficult to notice the gradual changes that the disease causes to your vision. Signs of the disease on your cornea in its early stages can also be difficult to detect, even by a highly trained doctor.
Once Fuchs’ causes noticeable changes to the cornea, it can feel as if the disease developed all of a sudden, even though this is not what happened. It is like sitting on the beach and realizing that the tide is suddenly low without noticing that the tide has been gradually going down for hours. Most patients with Fuchs’ first notice that colors look washed out and that bright lights during the day as well as oncoming lights at night cause them to experience glare. Patients with these symptoms typically have early stages of the disease —well before the cornea has scarred significantly— which provides sufficient time for your doctor to intervene with appropriate therapy as needed.
How is Fuchs’ Dystrophy different from a cataract?
A cataract is a normal occurrence in every human eye. When the lens in the eye matures, it naturally becomes cloudy. A cloudy lens is called a cataract. Every eye over the age of 50 has a lens that has some degree of clouding. Some lenses are cloudier than others, even in the right and left eyes of the same patient.
Clouding of the lens is progressive, meaning that every year it will become worse. No medications, supplements, or dietary regimens are known to stop or reverse a cataract. There is no way to predict how slowly or quickly a cataract will progress. Every cataract progresses differently.
Most individuals over the age of 50 who experience visual symptoms from Fuchs’ also have at least some degree of a cataract. The cataract can cause the same symptoms as Fuchs’ —washed out colors, glare, and blurry vision— so it can sometimes be difficult for your doctor to know for sure whether it is mostly the Fuchs’ or mostly the cataract that is causing your vision problems. Most of the time, it is both.
What common eye conditions are unrelated to Fuchs’ Dystrophy?
Since you’re using your vision constantly, it’s easy to attribute all of your eye problems to Fuchs’, the condition that’s at the forefront of your mind, but this can be misleading and anxiety-provoking. Fuchs’ patients often have other, much more benign, eye problems in addition to Fuchs’ Dystrophy. How do you know whether your vision problems are caused more by Fuchs’ or more by dry eye, blepharitis, floaters, or presbyopia (or some other condition)? The easiest way is to consult your corneal specialist and ask them specifically about whether any conditions that are not Fuchs’ Dystrophy are contributing to your symptoms. The answer may help put your Fuchs’ in better perspective and, hopefully, put you at ease.
Dry Eye
Dry eye is a condition of the eye’s tear production system, the lacrimal glands. Patients with dry eye have an insufficient volume of tears lubricating the surface of their eyes. The symptoms of dry eye commonly include itching, burning, grittiness, eye achiness, and sensitivity to light, as well as fluctuating, blurry vision. All of these symptoms improve with replenishment of the tear volume with blinking, artificial tears, and other medical treatments. By contrast, blurriness caused by Fuchs’ Dystrophy does not typically improve with artificial tears and blinking.
Blepharitis
Blepharitis is a condition of the oil glands of the eyelid, which are located along the bottom of the eyelashes. Patients with blepharitis have impaired oil flow from their eyelids and a low-grade irritation/redness of the eyelid margin. The symptoms of blepharitis commonly include blurry vision and irritation in the morning —symptoms that noticeably improve with a hot shower or warm facecloth. Blepharitis can also cause fluctuating blurriness throughout the day, which typically improves with blinking, artificial tears, and other medical treatments. By contrast, blurriness caused by Fuchs’ Dystrophy does not typically improve with artificial tears, blinking, or a hot shower, but may improve over the course of the day.
Vitreous Floaters
Floaters are a condition of the vitreous gel inside of the eye, deep behind the pupil. Patients with floaters have a vitreous that has become more opaque in certain areas than in others, resulting in light-blocking specks that cast shadows on the retina, which is the eye’s equivalent of camera film. The symptoms of floaters are spots, strands, or even small clouds that move around in your vision. Floaters are most obvious when viewing a bright white background, like the snow on a ski slope or a computer screen. By contrast, the stationary cloudiness typical of Fuchs’ Dystrophy, which in some individuals can improve over the course of the day, does not move around in your vision.
Presbyopia
Presbyopia is a condition of the lens of the eye, which resides immediately behind the pupil. Starting around the age of 45, the lens begins to lose its ability to flex and focus light at near-distances, so that by the age of 65, you are mostly unable to read newsprint without wearing reading glasses or removing your distance-correcting glasses. Progression of this problem between your 40s and 60s is normal. Presbyopia is completely correctable with prescription or over-the-counter reading glasses. By contrast, difficulty reading due to the blurriness caused by Fuchs’ Dystrophy can be made easier with glasses and a bright reading light, but it cannot be entirely resolved.
What non-surgical therapies are available to treat Fuchs’ Dystrophy?
There are no medications, supplements, or diets available that are known to stop or reverse the progression of Fuchs’ Dystrophy.
Currently available eye drops treat the corneal swelling caused by Fuchs’ but not the diseased endothelial cells that cause the swelling. Muro128 is the most commonly prescribed eye drop for corneal swelling. It is a salt solution that comes in 2% and 5% concentrations, in an ointment or an eye drop, and can be applied to the cornea’s surface 3-4 times a day and at bedtime. The salt in Muro 128 dries out the superficial layers of a swollen cornea, much like salt dries out cured deli meats. The medication can be effective in the early stages of Fuchs’, but it does not address symptoms caused by guttata or deeper swelling. Salt solutions are ineffective in more advanced stages of the disease. Muro128 is available over the counter without a prescription and is also available as a less costly generic.
What types of corneal transplant surgery are available to treat Fuchs’ Dystrophy?
DMEK (Descemet Membrane Endothelial Keratoplasty) is currently the most advanced surgical treatment available for Fuchs’, but you should also be aware of other corneal transplant surgeries that came before DMEK.
PK (Penetrating Keratoplasty) was the first surgery available for Fuchs’ and has been in existence for about 100 years. EK (Endothelial Keratoplasty) was developed around 2000. Early forms of EK were eventually replaced by DSAEK, which has been the most common treatment for Fuchs’ in the United States since about 2011. DMEK was developed in 2006 and has become increasingly popular since the introduction of innovative surgical technology and techniques after 2010, including: eye bank-prepared DMEK tissue, specialized tissue-injection devices, methods for determining right-side-up orientation of DMEK tissue during surgery, approaches to manipulating and positioning DMEK tissue in the eye without directly touching the tissue, and the incorporation of gases used in retinal surgery to support DMEK tissue.
What are the differences between DMEK, DSAEK, and PK?
The primary structural difference between DMEK, DSAEK, and PK relates to which layers of the cornea are transplanted. The cornea has three major layers: the outside layer, which is known as the epithelium; the spongy middle layer, which is known as the stroma; and the innermost layer, which is known as the endothelium. Fuchs’ directly affects the endothelium, and in most cases the stroma and epithelium are healthy until the disease becomes more advanced.
PK replaces the stroma and epithelium as well as the endothelium with three layers from a donor cornea. A hole is cut into the cornea, like a manhole in the pavement. The three layers of donor cornea are then hand sewn into place to close the cornea, like a manhole cover.
DSAEK replaces the endothelium with part of a donor cornea. A small incision is made in the eye to gain access to the inside surface of the cornea. A hole is never made in the cornea. The endothelium is stripped off of the inside of the cornea. A partial-thickness piece of donor tissue made up of the donor’s endothelium and a thin layer of stroma is inserted into the eye. The eye is then filled with a bubble to press the tissue up against the cornea until the pumping action of the donor’s healthy endothelium sucks it into place.
DMEK also replaces the endothelium with part of a donor cornea, but the difference between DSAEK and DMEK is that DMEK donor tissue is made up of only endothelium. DSAEK replaces your diseased endothelium with stroma+endothelium. Because DSAEK adds stroma to your cornea, it does not return your eye to its normal anatomy. DMEK tissue does not have donor stroma. DMEK replaces your diseased endothelium with only donor endothelium; it is a 1-for-1 anatomic replacement. Otherwise, DMEK and DSAEK share the same surgical principals: a small incision, stripping off of the diseased endothelium, insertion of the donor tissue, and use of a bubble to press the tissue against the cornea until it sucks itself, or “attaches” itself, into place.
Since the vast majority of individuals in the United States with Fuchs’ have normally functioning stroma and epithelium, replacing all three layers of the cornea with a PK is no longer considered the standard-of-care surgical treatment for Fuchs’, with rare exception. In more advanced cases of Fuchs’, years of longstanding, severe corneal edema may have caused nearly opaque scarring in the corneal stroma and epithelium that will continue to impair vision, even after a successful DMEK or DSAEK procedure. In these cases, a PK may be necessary to restore clarity to the cornea despite it being possible to selectively repair the corneal endothelium with an EK procedure.
What are the benefits of DMEK over DSAEK and PK?
The primary benefits of EK (the umbrella term for both DSAEK and DMEK) over PK are safety, recovery time, freedom from rigid contact lenses (which must often, but not always, be worn after PK for optimal vision), and lower risk of rejection. PK requires a large incision that can rip open from minor trauma to the eye, even years after the surgery. Recovery from a PK is typically about one year, at which point many patients are prescribed a rigid contact lens to correct astigmatism created by the transplant; without a corrective lens in such cases, vision can be poor. Rejection rates with a PK are about 18-23%.
DSAEK is a very good form of EK, but it is not the most advanced version of the surgery. The primary advantages of DSAEK over PK are that it does not require a large incision, recovery time ranges from three to six months, rigid contact lenses are not required because the surgery does not cause large amounts of astigmatism, and rejection rates are about 5-8%.
DMEK offers the same benefits over PK, but with the addition of even more advantages over DSAEK. The primary benefits of DMEK over DSAEK are superior vision and a lower risk of rejection.
- More DMEK patients see 20/20 on the visual acuity chart compared to DSAEK patients in the short- and long-term after surgery.
- Recovery of vision with DMEK typically takes less than 1.5 to 3 months rather than 6 months or longer with DSAEK. Vision in DSAEK patients can continue to improve years after surgery, whereas vision in DMEK patients rapidly improves by 1.5 months and typically stabilizes by 3 months, if not sooner.
- Quality of vision with DMEK is superior to DSAEK.
- Rejection is lower with DMEK than DSAEK (about <1% vs. about 5-8%).
- Fewer DMEK patients develop the need for intraocular pressure lowering eye drops after surgery compared to DSAEK patients. DMEK’s lower rejection rate permits patients to use less potent steroid drops, which reduces the risk of associated ocular problems, such as elevated intraocular pressure, which can lead to glaucoma.
The only potential drawback of DMEK is that it can require another procedure in the clinic to replenish the bubble that presses the tissue against your cornea. DSAEK can also require replenishment of the bubble, but in general the need for this procedure —known as rebubbling— is less frequent in DSAEK than DMEK. The greater frequency of rebubbling after DMEK surgery is because the implanted tissue is extremely thin and delicate; as a result, it is much more prone to incompletely attaching to your cornea than the thicker tissue used in DSAEK.
However, not all rebubbling procedures are the same. Rebubbling after DSAEK frequently requires a second trip to the operating room. Rebubbling after DMEK only takes a few minutes and can be performed painlessly in the office without returning to the operating room.
Can thinner DSAEK tissue provide the same vision as DMEK?
DSAEK corneal transplants can be precut by an eye bank technician to different thicknesses specified by the surgeon. However, even the thinnest DSAEK cannot surpass the vision of a DMEK. DMEK corneal transplants restore normal corneal anatomy without introducing a redundant layer of donor corneal stroma. All DSAEK corneal transplants, regardless of their thickness, introduce a redundant layer of donor corneal stroma that is not found in nature.
What is DSO (Descemet Stripping Only)?
Descemet Stripping Only (DSO) is a surgical treatment for Fuchs’ that does not transplant any tissue from a donor cornea into your eye. Like DMEK and DSAEK, DSO strips the central corneal endothelium off of your cornea to remove the corneal guttata affecting your vision. Unlike DMEK and DSAEK, DSO does not replace the endothelium with a corneal transplant from a donor. Instead, DSO relies on your corneal endothelium to repopulate itself from the areas of your cornea that were not stripped. Unlike DMEK and DSAEK, DSO causes severe corneal swelling and loss of vision immediately after the procedure because there is no endothelium at the site of stripping. Over weeks to months, the swelling resolves —but not always— as the site of stripping is covered by endothelial cells that have migrated from elsewhere on the cornea’s innermost layer.
What are the Pros and Cons of DSO compared to DMEK and DSAEK?
The primary benefit of DSO over DMEK and DSAEK is that it completely eliminates the need for long-term steroid eye drops. Since DSO does not transplant donor tissue into your eye, the procedure is associated with no risk of rejection and therefore does not require steroids after your cornea has recovered from the procedure.
The main drawback of DSO is that the recovery process can be quite unpredictable. The time required for vision to fully recover can range widely from three weeks, to three months, to never. When the recovery of vision after DSO is rapid, patients can be quite happy with the results. However, a prolonged recovery period can not only present emotional challenges to patients, which are not insignificant, but also render permanent scarring to the cornea that reduces vision forever. This is why any patient undergoing DSO should be prepared to undergo a DMEK or DSAEK surgery to “rescue” the procedure if it fails, before permanent damage occurs to the cornea. At what point in the recovery period a DSO should be rescued will vary among patients and surgeons.
Another significant drawback of DSO, which was first performed in 2016, is that the procedure is still in its infancy compared to DMEK and DSAEK, which have been performed since the early 2000s. Although a growing number of surgeons are beginning to perform DSO, the total number of DSO procedures ever performed in the USA pales in comparison to the number of DMEK and DSAEK surgeries performed in just one year. As a result, there is still much that remains unknown about DSO, including whether or not it will provide good vision in the long-term. Unlike DMEK and DSAEK, there are no multi-year follow-up studies on DSO.
Finally, the medications that speed recovery after DSO are still considered experimental in the USA. As of 2019, no FDA-approved medications for DSO are available for doctors to prescribe to patients.
Am I candidate for DSO?
Not all Fuchs’ patients are candidates for DSO. You should speak with your surgeon about whether you can consider DSO as an alternative to DMEK and DSAEK. In general, only patients with mild Fuchs’ are candidates for the procedure. Since DSO is frequently performed together with cataract surgery, another option to consider is having cataract surgery alone, which can improve vision in patients with mild Fuchs’ so long as the cataract surgery does not cause any undue trauma to the cornea.
When should I have surgery for Fuchs’ Dystrophy?
The presence of Fuchs’ does not mean you should have surgery. Only symptoms caused by Fuchs’ that restrict your daily activities by affecting your visual function should be addressed surgically.
One patient may suffer a loss of visual function from moderate guttata and therefore consider having surgery. But a different patient may not notice moderate guttata and instead choose to postpone surgery until their Fuchs’ has worsened. The same corneal abnormalities can affect different people differently, and there is no right or wrong time to make the decision to have DMEK surgery. The timing is up to you and it is based on your visual function. The procedure can be performed as soon as your vision interferes with your quality of life —at whatever age that might be.
If your eye is painful from Fuchs’, the decision to have surgery may be more urgent because pain can have a profound effect on your ability to function. Scarring of the cornea from Fuchs’ may also prompt you to have surgery somewhat urgently. It is difficult to know how much corneal scarring will affect your visual results after DMEK. In general, eyes with corneal scarring do not see as well as eyes without it, although scarring can sometimes improve quite substantially after surgery. Undergoing DMEK surgery before corneal scarring has become visually significant gives you a better chance of having good vision after the procedure than waiting until severe scarring has occurred.
Is DMEK surgery painful?
DMEK surgery is not painful. Your eye is numbed with medication to keep you comfortable during the procedure. A typical DMEK surgery does not take more than 1 hour. Because the operation is so short and comfortable, in most cases you are awake for the surgery. A sedative is given to you by the anesthesia team to relax you during the procedure.
How long will it take for my vision to recover from DMEK surgery?
Vision immediately after DMEK surgery is quite poor because a gas bubble is placed in the eye at the end of the procedure. The gas bubble covers your pupil and makes your vision very blurry. Your eye absorbs the gas bubble over the course of one week. Vision becomes noticeably better once the bubble has been absorbed. Vision typically improves over the first six weeks before it begins to level off. Most patients typically have stable vision by three months after surgery, but it can still continue to improve until six months.
Why do I need a very small additional hole placed in my iris (“peripheral iridotomy”) to have DMEK surgery?
The gas bubble that is placed in the eye at the end of the DMEK procedure not only affects vision, it also affects the normal flow of fluid in the eye. The eye is constantly making fluid, which flows from behind the iris, through the pupil, and into the front of the eye. The flow of fluid is completely blocked by the bubble that is placed in the front of the eye during DMEK surgery. Blockage of this flow of fluid can cause high eye pressure during the first few days after surgery. To prevent fluid from building up behind the iris, an additional, very small, hole is placed in the iris to allow fluid to pass freely into the front of the eye while the bubble is blocking the pupil. This small hole is called a peripheral iridotomy and it remains in the iris after the bubble has been absorbed, but it does not affect vision, and you do not know it is there because it is so small.
How long do I need to lie on my back after DMEK surgery?
Lying on your back after DMEK surgery is critical to successful attachment of the transplant to your own cornea. After you leave the hospital on the day of your surgery and for the two days that follow, you will need to lie on your back for two hours at a time, followed by two hours of sitting or standing. You will also need to sleep on your back. These positioning requirements stop once you have reached the third day after surgery.
If rebubbling is going to be required, it is typically performed two weeks after surgery because the DMEK tissue has not completely attached itself to your cornea and is in need of additional support from another bubble. Very rarely, someone may require more than one rebubbling procedure. Rebubbling is painless and can be performed in the office in a few minutes; another trip to the operating room is usually not needed. If rebubbling is performed, lying on your back is again required for the two days that follow the procedure in the same manner discussed above.
Should I have cataract surgery before DMEK surgery?
The decision for an individual with Fuchs’ to have cataract surgery is complicated and should be discussed with your doctor. If your disease is not advanced, cataract surgery can sometimes improve the visual symptoms caused by Fuchs’, but it can also make them worse. This is because cataract surgery causes minor trauma to the endothelial cells, even in corneas without Fuchs’. Extra precaution should be taken during cataract surgery in individuals with Fuchs’ to minimize potential damage to the endothelial cells. If the damage caused by cataract surgery is too great, a DMEK corneal transplant may be required. In such cases, it is difficult to know whether these individuals would have needed a corneal transplant even if they had not had cataract surgery.
It is usually not possible for individuals with Fuchs’ to escape cataract surgery in their lifetime. Most patients over the age of 50 who have a DMEK corneal transplant before having cataract surgery will need cataract surgery within a few years. Having cataract surgery after a DMEK corneal transplant is possible, but in principal, it is not ideal for the health of the transplanted endothelial cells because they are exposed to another procedure. In practice, however, it is safe to perform cataract surgery after a DMEK so long as extra precautions are taken to minimize potential damage to the transplanted cells.
One option is to either combine cataract surgery with a DMEK corneal transplant in one procedure, or to plan for a two-stage procedure in which the surgeries are separated by a short period of time (cataract first, DMEK second). Most patients prefer one of these options because addressing both the cataract and Fuchs’ provides the best possible chance of restoring clear, vivid vision.
It is sometimes a better option to perform the DMEK procedure first, followed by the cataract surgery, or to postpone cataract surgery altogether until the cataract significantly affects the vision. In patients who have had prior laser vision correction, such as LASIK, it can be advantageous to perform the DMEK surgery before the cataract procedure so that the lens implant at the time of cataract extraction can be more accurately selected based on stable corneal measurements, which change after DMEK surgery. In patients with minimal if any signs of cataract, it can sometimes be better to perform only a DMEK surgery because their native lenses are not significantly affecting vision. This scenario is not that common but is more often the case in patients on the younger side of 50, and rarer among patients 60 years and above.
Will I need glasses after DMEK surgery?
DMEK surgery with or without cataract surgery will change your corrective glasses prescription. Although it is rare, it is possible that further procedures may be required if your corrective glasses prescription is not to your liking. Further procedures can include laser vision correction and, rarely, a return to the operating room to exchange the lens implant.
What are the risks of DMEK surgery?
DMEK surgery is safe in the hands of an experienced surgeon, but as with any operation, there are risks. Discussion of these risks is not meant to frighten or upset you; it is to ensure that you have carefully weighed the benefits and risks of DMEK surgery before deciding to go ahead with the procedure. Although improved modern techniques have greatly reduced their occurrence, complications can and do occur with DMEK surgery, but severe complications are very rare. Fortunately, for most individuals, the chances of success with DMEK surgery are excellent. On the other hand, without corneal transplant surgery, the loss of visual function caused by Fuchs’ cannot be restored because the cornea will not get better on its own.
Once you receive a corneal transplant of any kind, the transplant will always —for the rest of your life— have a risk of rejection. DMEK has the lowest risk of rejection among corneal transplant surgeries; however, it is not zero risk. The risk of rejection is lowest if you religiously take steroid eye drops as your doctor prescribes them (about <1%). It may be possible to stop steroid eye drops after one year, but only if you are willing to accept a slightly higher risk of rejection (about 6%). Rejection of a DMEK transplant is easily treated with intensive steroid eye drops. Rejection does not ruin the DMEK transplant, but it probably shortens its long-term lifespan.
Can Fuchs’ Dystrophy come back after DMEK surgery?
Fuchs’ Dystrophy cannot come back after you receive a DMEK corneal transplant. A DMEK corneal transplant may last you for a lifetime, but it may also need to be replaced in 10-15 years because of the normal loss of endothelial cells that affects all corneas, even transplanted ones. But if a DMEK transplant ever needs to be replaced, it is not because of recurrence of Fuchs’.
How long does a DMEK transplant last?
DMEK transplants, like DSAEK and PK transplants, have a limited lifespan. Long-term studies on DMEK are still underway, but early indications are that DMEK transplants last at least as long as DSAEK transplants. On average, the life of a DMEK transplant should be at least 10-15 years or more, but it’s impossible to predict what the survival of your transplant will be. The lifespan of a DMEK transplant will vary from transplant to transplant, even in the same individual.
What experimental treatments are being developed to treat Fuchs’ Dystrophy in the future?
Researchers in Japan, Europe, and the United States are developing a therapy for Fuchs’ that does not involve a corneal transplant from a donor. The ultimate goal of the procedure is to genetically engineer normal endothelial cells derived from your own body in a laboratory, then to replicate, or culture, the cells that have been “cured” of the disease to grow replacement endothelial cells for your cornea. Genetically engineered endothelial cells would either be injected into the eye or surgically transplanted using techniques similar to DMEK or surgeries that have yet to be developed. To promote healing of the genetically engineered endothelial cells on your cornea, classes of medications currently being studied by the FDA for DSO might be used in conjunction with conventional steroid eye drops in the short term. Since the cells would be derived from your own body, long-term steroids would be unnecessary because rejection risk would theoretically be zero.
The final frontier in the treatment of Fuchs’ Dystrophy would be to cure the disease without any form of surgery. As our understanding of the genetic basis of Fuchs’ improves, in conjunction with scientific advances in genetic therapy across all fields of medicine, it may one day be possible to treat Fuchs’ with medications that deliver a genetic cure for the disease. The study of genetically engineered tissue and genetic cures for Fuchs’ are well under way, but they are both probably at least a decade away, if not more, from being evaluated in clinical trials.
