Pre-descemet corneal dystrophy is a rare eye condition that affects the clear front window of the eye, called the cornea. It is often noticed in adulthood during a routine eye exam, and many people with Pre-descemet corneal dystrophy have no symptoms or only mild blurred vision. The changes in the cornea usually develop slowly and can be lifelong, but not everyone will have the same experience. Pre-descemet corneal dystrophy does not usually affect life expectancy, and it is not generally considered life-threatening. Many living with Pre-descemet corneal dystrophy only need monitoring, while treatment for bothersome vision changes may include glasses, contact lenses, or other eye care based on how the cornea is affected.
How many people live with Pre-descemet corneal dystrophy?
Pre-descemet corneal dystrophy is so rare that there is no widely accepted estimate of how many people live with it worldwide or in the United States; major rare-disease references describe it as very rare but do not provide a reliable population count (Orphanet, 2024; National Organization for Rare Disorders, 2024). In other words, no single authoritative source currently reports a dependable global or U.S. head count for this specific condition.
Overview
Pre-descemet corneal dystrophySymptoms
Pre-descemet corneal dystrophy often causes no noticeable symptoms. When signs do appear, they may include tiny cloudy spots deep in the cornea and, less often, blurred vision or glare, usually found on an eye exam.
Outlook and prognosis
Pre-descemet corneal dystrophy usually changes very slowly and often does not affect day-to-day vision. Many living with pre-descemet corneal dystrophy keep stable eyesight for years, though regular eye checks help watch for uncommon progression or other eye problems.
Causes and risk factors
Pre-Descemet corneal dystrophy usually results from an inherited genetic change, although some cases appear for the first time in a family. Family history is the main risk factor. Lifestyle and environmental causes are not known.
Genetic influences
Genetics seem to play a role in Pre-descemet corneal dystrophy, but the exact genes are not well defined. In many people, it appears sporadic rather than strongly inherited, so family patterns can be unclear.
Diagnosis
Pre-descemet corneal dystrophy is usually suspected during a slit-lamp eye exam, when an eye specialist sees its characteristic corneal changes. The diagnosis of pre-descemet corneal dystrophy may be confirmed with imaging and, in some cases, genetic tests.
Treatment and drugs
Pre-descemet corneal dystrophy often needs no treatment if vision stays clear, and many people are simply monitored with regular eye exams. If dryness, glare, or blurred vision becomes bothersome, lubricating eye drops and updated glasses or contact lenses may help.
Symptoms
Pre-descemet corneal dystrophy usually does not cause day-to-day eye problems, and many people only learn they have it during a routine eye exam. For many people with Pre-descemet corneal dystrophy, the main finding is a pattern of tiny cloudy spots deep in the cornea, the clear front surface of the eye. Vision is often normal, but some people notice mild blur, glare, or halos, especially in bright light. The early features of Pre-descemet corneal dystrophy can be easy to miss because they are often subtle and painless.
Many people with this condition have no noticeable eye symptoms at all. Reading, driving, and screen use may feel completely normal, especially early on.
An eye doctor may see tiny gray, white, or dusty-looking spots deep in the cornea. These spots usually do not cause pain or redness.
Some people notice slightly blurry vision if the cloudy areas sit near the center of the cornea. This can make fine print or distant details seem a little less sharp.
Bright sunlight, headlights, or strong indoor lighting can sometimes cause extra glare or halos. Many living with Pre-descemet corneal dystrophy notice this most in bright light or at night.
How people usually first notice Pre-descemet corneal dystrophy?
Pre-descemet corneal dystrophy is often not something people feel right away; many first learn about it during a routine eye exam, when an eye doctor sees tiny deep corneal spots or flecks before they cause any obvious trouble. In some people, the first signs of pre-descemet corneal dystrophy are mild blurry vision, glare, or halos around lights, but many living with this condition have little to no symptoms, especially early on. Because it can be subtle and may run in families, how pre-descemet corneal dystrophy is first noticed often depends on a careful slit-lamp exam rather than a dramatic change in vision.
Types of Pre-descemet corneal dystrophy
No distinct types of Pre-descemet corneal dystrophy are widely recognized.
Can I slow down the onset of symptoms?
Probably not: for pre-descemet corneal dystrophy, there is no strong evidence that lifestyle changes or medicines can meaningfully delay when symptoms start, and many people with this condition never notice symptoms at all. Research has not shown that diet, exercise, supplements, or other habits can prevent it, because it is usually related to inherited changes in the clear front part of the eye rather than something you can control. Regular eye exams are still helpful so any vision changes can be picked up early, and while good overall eye care is sensible, it may support comfort but is not known to stop the condition from starting.
What genetics can tell you about symptoms
For pre-Descemet corneal dystrophy, genetics can sometimes show that the condition runs in families, but it usually cannot clearly predict which symptoms someone will have, how strong they will be, or exactly when they will start. Many people living with this condition have few or no day-to-day symptoms, and when symptoms do occur, they are often mild and can vary even among relatives. Because this is a rare corneal condition and the genetic causes are not fully worked out, genetic findings are usually more helpful for confirming that it is inherited than for forecasting the course of symptoms.
Causes and risk factors
Pre-Descemet corneal dystrophy usually comes from an inherited gene change that affects the clear front surface of the eye. It can run in families, and in some people the change may arise for the first time instead of being passed down. A family history of Pre-Descemet corneal dystrophy is the main known risk factor, and age can affect when the tiny corneal spots are first seen. Lifestyle and environment are not known to be major causes, but dry eye or other corneal problems may make vision changes easier to notice. Knowing your family history is a good first step.
What are the most common causes or risk factors?
The most common known cause of pre-descemet corneal dystrophy is an inherited gene change, so having a family history is the main risk factor. In some people, it can happen along with a genetic skin condition called X-linked ichthyosis, which also runs in families. There are no well-proven lifestyle or environmental causes, and it is not thought to be caused by eye strain, screen use, diet, or a minor eye injury.
Environmental and biological risk factors
Pre-descemet corneal dystrophy is a rare corneal condition, and most known influences are biological rather than environmental. Doctors often group risks into internal (biological) and external (environmental). For this condition, clear outside triggers have not been established, and many cases are linked to age-related changes or certain underlying conditions. The exact pattern can vary by subtype.
Pre-descemet corneal dystrophy is often first noticed in adulthood, and the tiny corneal spots may be easier to detect as people get older. Age does not guarantee the condition, but it is one of the clearest biological patterns reported.
A recognized form of pre-descemet corneal dystrophy is seen more often in people living with X-linked ichthyosis, a skin condition present from birth. In that setting, the corneal changes reflect an underlying body process rather than damage from the outside environment.
In the form tied to X-linked ichthyosis, males are affected more often, while some female carriers may have milder eye findings. This difference relates to biology in that subtype and does not explain every case of pre-descemet corneal dystrophy.
No well-established environmental exposures are known to cause pre-descemet corneal dystrophy. Routine eye use, screen time, and common day-to-day irritants have not been shown to be risk factors.
Genetic risk factors
Most people with pre-descemet corneal dystrophy find out about it during a routine eye exam, and it is natural to wonder whether it runs in families. Family history is one of the main genetic risk factors for pre-descemet corneal dystrophy, and some families show a clear inherited pattern. Carrying a genetic change doesn’t guarantee the condition will appear, and for the classic form, the exact gene has not been firmly confirmed in most cases.
Family history: Having a close relative with pre-descemet corneal dystrophy raises the chance that other family members may have it too. This is why eye doctors often ask whether relatives were ever told they had similar corneal changes, even if their vision was normal.
Dominant pattern: In some families, pre-descemet corneal dystrophy appears to follow an autosomal dominant pattern, meaning one changed copy of a gene may be enough to pass on the tendency. If that pattern is present in a family, each child of an affected parent may have about a 1 in 2 chance of inheriting it.
Unknown main gene: For classic pre-descemet corneal dystrophy, researchers have not confirmed one single gene as the cause in most people. That can make genetic testing less straightforward than it is for some other inherited eye conditions.
STS-linked association: A very similar pre-Descemet corneal pattern can occur in people with X-linked ichthyosis, which is caused by changes or missing pieces in the STS gene. This is considered a related genetic association rather than the proven cause of every case of pre-descemet corneal dystrophy. Because it is X-linked, it is seen mainly in males.
Lifestyle risk factors
Lifestyle habits do not cause pre-descemet corneal dystrophy, but they can influence eye comfort, visual symptoms, and the chance of secondary surface problems. In practice, how lifestyle affects pre-descemet corneal dystrophy is mostly through irritation, dryness, and added stress on an already abnormal cornea. Habits that protect the ocular surface may help reduce fluctuating vision, foreign-body sensation, and discomfort. Choices that increase inflammation or trauma can make symptoms more noticeable even if they do not create the dystrophy itself.
Frequent or forceful eye rubbing can irritate the corneal surface and make discomfort more noticeable. It may also worsen tiny epithelial injuries, which can increase blurred vision or irritation in someone with pre-descemet corneal dystrophy.
Long wear times, poor lens hygiene, or sleeping in lenses can add friction and reduce oxygen at the corneal surface. In pre-descemet corneal dystrophy, that extra stress may worsen irritation and raise the risk of infection or surface breakdown.
Heavy screen use, low blink rates, air conditioning, and very dry indoor air can worsen ocular surface dryness. This can make visual fluctuations, grittiness, and light sensitivity more prominent when the cornea is already structurally abnormal.
Smoking exposes the eyes to irritants and promotes surface inflammation and dryness. For people with pre-descemet corneal dystrophy, this may increase redness, burning, and day-to-day symptom burden even though smoking is not the cause of the condition.
Risk prevention
Pre-descemet corneal dystrophy usually cannot be prevented because it is often linked to inherited changes that affect the cornea. For many living with pre-descemet corneal dystrophy, prevention is really about lowering the chance of irritation, vision problems, and other eye complications over time. Different people need different prevention strategies—there’s no single formula.
Regular visits with an eye doctor can help track changes in the cornea before they start to affect daily tasks like reading or night driving. These visits are also the best way to catch other treatable eye problems early, especially if there are early symptoms of pre-descemet corneal dystrophy.
Wearing protective glasses during sports, home repairs, or dusty work can help prevent scratches and minor injuries that may make symptoms worse. Sunglasses can also reduce glare and light sensitivity for some people with pre-descemet corneal dystrophy.
Frequent eye rubbing can irritate the cornea and may worsen discomfort if the eye surface is already sensitive. If itching is a problem, treating allergies or dry eye is usually safer than rubbing.
Keeping the eyes well lubricated with doctor-recommended artificial tears can reduce irritation and help the corneal surface stay healthier. This may be especially helpful if your eyes feel gritty, tired, or blurry later in the day.
Can you prevent Pre-descemet corneal dystrophy?
No, pre-Descemet corneal dystrophy usually cannot be prevented. It is most often linked to inherited changes that affect the clear front part of the eye, so there is no proven lifestyle step that can stop it from developing. Regular eye exams can still help monitor it over time and make sure any new vision changes are checked.
Transmission
Pre-Descemet corneal dystrophy is not an infection, so it does not spread from one person to another through touch, tears, kissing, coughing, or shared items like towels. For many people with pre-Descemet corneal dystrophy, the corneal changes are linked to a gene change rather than anything they caught.
How pre-Descemet corneal dystrophy is inherited can vary, but it may run in families, often in an autosomal dominant pattern, which means a child has a 1 in 2 chance of inheriting it if one parent has the condition. Some cases appear without a clear family history, which can happen when a new gene change arises or when earlier family members had such mild signs that no one noticed them.
When to test your genes
Genetic testing is not usually needed for pre-Descemet corneal dystrophy, because it is often found during an eye exam and rarely changes treatment. It may be worth discussing if the diagnosis is unclear, several relatives are affected, symptoms begin early, or there are signs of a broader inherited condition, especially for family planning and tailored follow-up.
Diagnosis
Pre-descemet corneal dystrophy is usually diagnosed during an eye exam, often after an eye doctor notices small changes in the cornea even when vision is normal or only mildly affected. Many living with pre-descemet corneal dystrophy do not have obvious day-to-day symptoms, so the condition may be found by chance at a routine visit. Getting a diagnosis is often a turning point toward answers and support.
An eye doctor checks the front of the eye carefully and looks for tiny opacities in the deep cornea just in front of Descemet membrane. Their location and pattern can strongly suggest pre-descemet corneal dystrophy.
This is the main test used in the diagnosis of pre-descemet corneal dystrophy. A bright microscope lets the doctor see the small gray-white spots or flecks in detail and judge whether both eyes are affected.
Doctors usually measure visual acuity to see whether the corneal changes are affecting sight. Many people with pre-descemet corneal dystrophy have little or no vision loss, which can help guide follow-up.
Your provider may suggest corneal photography or other imaging to look closer and document the deposits over time. These images can help confirm the depth of the changes and track whether they remain stable.
How is Pre-descemet corneal dystrophy diagnosed?
Pre-descemet corneal dystrophy is usually diagnosed by an eye doctor during a full eye exam, especially with a slit-lamp exam, which is a bright microscope used to look closely at the clear front surface of the eye and spot the tiny cloudy dots in its deeper layers. Sometimes the doctor may use special cornea scans or close-up imaging to confirm the finding and make sure it is not another eye condition. Genetic testing is not usually needed, but it may be considered if several family members are affected or if another inherited eye problem is suspected.
Stages of Pre-descemet corneal dystrophy
Pre-descemet corneal dystrophy does not have defined progression stages. This is because it is usually a stable or very slowly changing eye condition, and many people never notice day-to-day changes in their vision. Often the process begins when you notice changes in daily life, but with pre-descemet corneal dystrophy there may be no symptoms at all, and early symptoms of pre-descemet corneal dystrophy are often absent or very mild. Doctors usually find it during a slit-lamp eye exam, and follow-up visits may be used to check whether the cornea and vision are staying the same over time.
Outlook and prognosis
The outlook for people with pre-descemet corneal dystrophy is generally excellent, because the condition is usually mild, slowly progressive or even stable, and often discovered incidentally on eye examination. Most affected individuals maintain good vision throughout life, and many never need any treatment beyond routine follow-up with an eye care specialist. When visual symptoms do occur, they are typically limited and can often be managed with supportive measures, while severe vision loss is uncommon. Life expectancy is not affected, and there is no known increase in mortality related to this corneal dystrophy. Prognosis may vary somewhat depending on the exact subtype and whether it occurs alone or as part of a broader syndrome, so individualized ophthalmic monitoring remains important.
Long-term effects
For many living with Pre-descemet corneal dystrophy, the long-term picture is often mild and stable. Long-term effects vary widely, but many people have few day-to-day problems for years and some never notice clear vision changes at all. When changes do happen, they usually relate to the clear front window of the eye and may be found during an eye exam before they cause symptoms. In some people, early symptoms of Pre-descemet corneal dystrophy can include subtle blur or glare, especially if the cornea becomes less clear over time.
Many people with Pre-descemet corneal dystrophy keep good vision over the long term. In many cases, the corneal changes remain small and do not noticeably affect reading, driving, or other daily tasks.
Some may find that vision becomes slightly hazy or less sharp over time. This is usually gradual rather than sudden, and it can be more noticeable in certain lighting conditions.
Bright sunlight, headlights, or strong indoor lighting may become more bothersome for some people. For many, symptoms stay mild, but glare and halos can make night driving feel less comfortable.
The cornea can develop more visible cloudy or dotted changes as the years go by. Doctors may track these changes over years to see whether they stay in the background or begin to affect sight.
How is it to live with Pre-descemet corneal dystrophy?
For many people living with pre-Descemet corneal dystrophy, daily life feels almost completely normal because this corneal change often causes no symptoms or only mild, gradual blur in vision. If vision does become affected, some may notice trouble with fine detail, glare, or reading for long periods, which can make eye exams, updated glasses, and regular follow-up with an eye specialist part of routine life. The condition does not spread from person to person, so it does not pose a risk to family, friends, or coworkers, although loved ones may help with practical support if vision changes become more noticeable over time.
Treatment and drugs
Pre-descemet corneal dystrophy often does not need active treatment because many people have no symptoms and their vision stays normal. If symptoms do occur, treatment is usually aimed at comfort, such as lubricating eye drops for dryness or irritation and regular eye checkups to watch for changes. If first-line treatments don’t help, specialists may look for another eye problem that could be causing blurred vision, since pre-descemet corneal dystrophy itself often stays mild. For many living with pre-descemet corneal dystrophy, care is mainly about monitoring rather than medication, and your eye doctor can explain whether any treatment is actually needed in your case.
Can you cure Pre-descemet corneal dystrophy?
No, there is no cure right now for pre-descemet corneal dystrophy, a rare condition that affects the clear front part of the eye. Many people do not need treatment because it often causes few or no symptoms, but eye doctors can use lubricating drops to ease irritation and, if sight becomes affected, surgery on the cornea may help improve vision.
Non-drug treatment
Many living with pre-descemet corneal dystrophy do not need active treatment, especially if vision stays clear and symptoms are mild. Care usually centers on protecting day-to-day vision, easing surface irritation, and watching for changes over time. Because this condition can vary from person to person, treatment is often tailored to how much it affects reading, driving, screen use, or other routine tasks. Not every approach works the same way, so follow-up care helps match support to your needs.
Regular visits with an eye specialist help track whether the cornea is changing and whether vision is being affected. For many, treatment begins not at the pharmacy, but with simple monitoring because pre-descemet corneal dystrophy often stays stable for long periods.
Updated glasses or carefully fitted contact lenses can sharpen vision if the cornea causes blur or glare. This can matter in everyday moments, like struggling with road signs at night or needing larger print to read comfortably.
Magnifiers, brighter lighting, glare filters, and large-print tools can help if ordinary glasses are not enough. These supports are part of non-surgical treatment for pre-descemet corneal dystrophy when fine detail becomes harder to see.
If the eye surface feels gritty or tired, using a humidifier, taking screen breaks, and avoiding drying air from fans can help reduce irritation. Simple routines—like blinking more fully during computer work or resting your eyes between tasks—can have lasting benefits.
Your genes may have an impact on how drugs work for you
People living with pre-descemet corneal dystrophy usually do not need special medicine for the condition itself, and when treatment is used, it is often simple eye care such as lubricating drops for dryness or irritation. At this time, there is no well-established evidence that the genetic changes linked with this eye condition clearly change how these common treatments work or raise the risk of side effects in a predictable way. In other words, genetic drug-matching, sometimes called pharmacogenomics, is not a routine part of care for pre-descemet corneal dystrophy.
Pharmacological treatments
Most people with Pre-descemet corneal dystrophy do not need medicine because it often causes few or no symptoms. When treatment is needed, it is usually aimed at comfort rather than changing the cornea itself. In practice, treatment for pre-descemet corneal dystrophy most often means lubricating eye drops or ointment if the eyes feel dry, gritty, or mildly irritated.
There is no medicine known to reverse or cure Pre-descemet corneal dystrophy. Many living with this condition are simply monitored and do not need prescription treatment.
Lubricating eye drops such as carboxymethylcellulose, hypromellose, or polyethylene glycol can help if the eye surface feels dry or scratchy. These drops support comfort and clearer day-to-day vision, but they do not remove the corneal changes.
Nighttime eye ointments, often made with mineral oil or white petrolatum, may help if symptoms are more noticeable on waking. For some, taking medicine daily becomes as routine as using ointment before bed when the eyes feel irritated.
Antibiotic or steroid eye drops are not standard treatment for Pre-descemet corneal dystrophy itself. If they are used, it is usually because another eye problem is present and an eye specialist has found a separate reason for them.
Genetic influences
Because pre-Descemet corneal dystrophy is often picked up on an eye exam rather than from major vision changes, many people first ask whether pre-Descemet corneal dystrophy is inherited. The short answer is that it can be, although the genetics are not fully worked out in every family. Reports of several affected relatives suggest that some cases are passed down, sometimes in a pattern where an affected parent can pass the condition to a child. Family history is one of the strongest clues to a genetic influence. At the same time, not everyone with pre-Descemet corneal dystrophy has a clear family pattern or an identified genetic cause, and similar corneal findings can occasionally appear as part of another inherited disorder. If relatives have had the same eye finding, or there are other symptoms outside the eye, an eye specialist or genetic counselor may help decide whether genetic testing is likely to add useful answers.
Is Pre-descemet corneal dystrophy genetic?
Genetics seem to play a role in Pre-descemet corneal dystrophy, but the exact genes are not well defined. In many people, it appears sporadic rather than strongly inherited, so family patterns can be unclear.
Having a genetic risk is not necessarily a diagnosis
Genetic variants are common in the general population and are a normal part of human biology. Most do not have a direct effect on health and simply reflect natural human diversity. For many genes, having a variant connected with a condition suggests a possible link rather than a definite diagnosis, especially when several genes and environmental factors are involved. In some situations, though, a single well-characterized variant in a particular gene is enough to confirm a diagnosis.
Pharmacogenetics—how genetics influence drug effects
For many living with pre-descemet corneal dystrophy, treatment is usually aimed at easing day-to-day issues like mild blur, glare, or dry-eye discomfort rather than changing the corneal changes themselves. Genetics can still matter because they may help confirm that the cloudy spots in the cornea are part of an inherited dystrophy and not another eye condition that needs a different approach. Not every difference in response is genetic, but with pre-descemet corneal dystrophy there is currently no well-established gene-based way to choose one eye drop or medicine over another. In practice, the treatment for pre-descemet corneal dystrophy is often supportive, such as lubricating drops if the eyes feel irritated, while regular eye exams help track whether vision stays stable. If several family members have similar corneal findings, genetic information can also guide counseling about who else in the family may want an eye check. So, for pre-descemet corneal dystrophy, genetics usually influence diagnosis, family planning, and follow-up more than they influence drug choice.
Interactions with other conditions
Many living with pre-descemet corneal dystrophy have few day-to-day problems, but other eye conditions can make blurry vision, glare, or irritation more noticeable. Dry eye, eyelid inflammation, cataracts, and other common eye problems do not usually cause pre-descemet corneal dystrophy, yet they can add to the same visual complaints and make it harder to tell what is driving symptoms. Another important aspect is how it may link with other diseases: in some families, similar deep corneal specks can appear as part of a broader inherited condition rather than on their own. That is one reason an eye specialist may ask about skin findings, family history, or other health issues if the corneal changes look unusual. For many, this can mean the main question is not whether pre-descemet corneal dystrophy is dangerous, but whether another eye or inherited condition is present at the same time and needs attention.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
What other conditions can cause similar symptoms to Pre-descemet corneal dystrophy?
Other problems can look similar, especially other inherited cornea conditions that cause tiny cloudy spots in the clear front part of the eye, as well as age-related cornea changes that are harmless but show up on an eye exam. Eye doctors may also think about deposits caused by certain medicines or by rare body-wide conditions that leave material in the cornea. Because these problems can look alike, an eye exam with a microscope is usually needed to tell them apart.
History
Many living with pre-descemet corneal dystrophy do not notice anything unusual at first. It is often found during a routine eye exam, when an eye doctor sees tiny changes deep in the clear front window of the eye, just in front of a thin back layer called Descemet membrane. That quiet, incidental way of being discovered shaped its early history: doctors recognized the eye pattern before they fully understood what it meant for everyday vision.
As medical science evolved, pre-descemet corneal dystrophy was described in case reports and small family studies rather than in large early surveys. At first, it was grouped mainly by what doctors could see through a slit-lamp exam, a microscope with a bright light used to look closely at the eye. Over time, specialists learned that these deeper corneal deposits could appear in more than one setting, and that not everyone with the condition has symptoms. This helped separate pre-descemet corneal dystrophy from other corneal dystrophies that are more likely to blur vision or cause painful surface problems.
Later, improved imaging and microscopic study of corneal tissue gave a clearer picture of where the changes sit within the cornea and how they differ from similar disorders. Researchers also recognized that some cases run in families, although the genetic cause is discussed separately from the history of the condition. In recent decades, awareness has grown, and doctors have become better at telling pre-descemet corneal dystrophy apart from other causes of corneal specks or clouding. Knowing this history helps explain why many people hear about it only after an eye exam, and why the early symptoms of pre-descemet corneal dystrophy may be mild or absent altogether.