Fish Eye Disease
What is Fish Eye Disease?
Fish Eye Disease is a rare genetic disorder that affects how your body processes cholesterol and fats. The name comes from the cloudy appearance of the corneas, the clear outer layer of your eyes, which can look similar to fish eyes. This cloudiness happens because of problems with an enzyme called LCAT, which stands for lecithin cholesterol acyltransferase.
When LCAT does not work properly, fats build up in unusual places in your body. The corneal cloudiness is the most visible sign of this condition. Your body also has trouble making good cholesterol, known as HDL cholesterol. This leads to very low levels of a protein called Apolipoprotein A1, which is a key building block of HDL cholesterol.
Fish Eye Disease is considered a partial LCAT deficiency, meaning the enzyme still works somewhat but not well enough. This is different from complete LCAT deficiency, which is more severe. Most people with Fish Eye Disease have cloudy corneas but do not experience severe health problems. The condition is inherited in an autosomal recessive pattern, meaning you need to get a changed gene from both parents to develop it.
Symptoms
- Cloudy or hazy corneas that create a fish eye appearance
- Gradual vision problems, especially glare sensitivity
- Very low HDL cholesterol levels
- Reduced Apolipoprotein A1 levels in blood tests
- Elevated triglyceride levels
- Possible corneal pain or discomfort in some cases
Many people with Fish Eye Disease do not notice symptoms until the corneal cloudiness becomes significant. Some people are diagnosed during routine eye exams or blood work that shows unusual cholesterol patterns. Vision changes typically develop slowly over years.
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Causes and risk factors
Fish Eye Disease is caused by mutations in the LCAT gene. This gene provides instructions for making the LCAT enzyme, which plays a key role in cholesterol metabolism. When the gene has specific mutations, the enzyme can still process some fats but not others. This partial function leads to fat deposits in the corneas and abnormal blood lipid levels. The condition runs in families and requires inheriting two copies of the mutated gene, one from each parent.
There are no lifestyle or environmental risk factors that cause Fish Eye Disease. You cannot develop this condition from diet, stress, or other external factors. If both your parents carry one copy of the mutated LCAT gene, you have a 25% chance of inheriting two copies and developing the condition. Carriers with only one mutated gene typically do not show symptoms. The condition affects all ethnic groups but is extremely rare worldwide.
How it's diagnosed
Fish Eye Disease is diagnosed through a combination of eye exams and blood tests. An eye doctor can see the characteristic corneal cloudiness during a slit lamp examination. This clouding usually appears in both eyes and has a distinctive pattern. Blood tests show very low HDL cholesterol and very low Apolipoprotein A1 levels, which are hallmark signs of the condition. Rite Aid offers Apolipoprotein A1 testing as an add-on to help identify abnormal lipid patterns that may suggest Fish Eye Disease.
Genetic testing can confirm the diagnosis by finding mutations in the LCAT gene. Your doctor may also measure LCAT enzyme activity directly through specialized lab tests. Triglyceride levels are often elevated in people with this condition. Early diagnosis helps distinguish Fish Eye Disease from other causes of cloudy corneas and abnormal cholesterol levels. If your blood work shows unusually low Apo A1, your doctor can order additional testing to investigate further.
Treatment options
- Regular eye exams to monitor corneal cloudiness and vision changes
- Corneal transplant surgery in severe cases affecting vision
- Heart healthy diet low in saturated fats and processed foods
- Regular physical activity to support cardiovascular health
- Lipid lowering medications like fibrates to manage triglycerides
- Monitoring for cardiovascular disease risk with your doctor
- Genetic counseling for family planning decisions
- Annual lipid panels to track cholesterol and Apo A1 levels
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- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Fish Eye Disease is a rare genetic disorder that causes cloudy corneas and abnormal cholesterol metabolism. It happens when the LCAT enzyme does not work properly, leading to fat deposits in the eyes. The condition gets its name from the fish eye appearance of the cloudy corneas. Most people with this condition have low HDL cholesterol and low Apolipoprotein A1 levels.
The cloudiness comes from fat particles depositing in the cornea, the clear front part of your eye. When the LCAT enzyme does not function correctly, cholesterol and fats cannot be processed normally. These unprocessed fats accumulate in the corneal tissue, creating a hazy or milky appearance. The cloudiness typically affects both eyes and worsens gradually over time.
Fish Eye Disease is generally not life threatening, but it can affect quality of life. The main concern is vision impairment from corneal cloudiness, which may eventually require a corneal transplant. People with this condition may have a slightly higher risk of heart disease due to low HDL cholesterol. Regular monitoring with your doctor helps catch any cardiovascular concerns early.
Fish Eye Disease follows an autosomal recessive inheritance pattern. This means you need to inherit two copies of the mutated LCAT gene, one from each parent, to develop the condition. If both parents are carriers, each child has a 25% chance of having Fish Eye Disease. Carriers with just one mutated gene typically have no symptoms.
Yes, blood tests can reveal important clues about Fish Eye Disease. People with this condition have very low HDL cholesterol and very low Apolipoprotein A1 levels. Triglycerides are often elevated as well. Rite Aid offers Apolipoprotein A1 testing as an add-on, which can help identify abnormal lipid patterns that warrant further investigation.
Fish Eye Disease is a partial LCAT deficiency, while complete LCAT deficiency is more severe. People with Fish Eye Disease have cloudy corneas and lipid abnormalities but usually avoid kidney problems. Complete LCAT deficiency causes all the same symptoms plus kidney disease and anemia. The distinction depends on which parts of the LCAT enzyme still function.
Not everyone with Fish Eye Disease needs a corneal transplant. Many people have mild cloudiness that does not significantly affect vision. Transplants are considered only when the cloudiness causes serious vision impairment that interferes with daily activities. Your eye doctor will monitor your corneas over time and discuss treatment options if vision declines.
While diet and lifestyle cannot cure Fish Eye Disease, they can support overall heart health. Eating a diet low in saturated fats and high in vegetables, fruits, and whole grains helps manage triglycerides. Regular exercise supports cardiovascular function and may help improve lipid profiles. These changes work best alongside medical treatment and regular monitoring.
Most doctors recommend annual blood work to monitor your lipid levels, including HDL cholesterol, triglycerides, and Apolipoprotein A1. You should also have regular eye exams, typically every six to 12 months, to track corneal cloudiness. Your doctor may adjust testing frequency based on your specific situation and any changes in symptoms.
Currently, there is no cure for Fish Eye Disease because it is caused by genetic mutations. Treatment focuses on managing symptoms and preventing complications. Corneal transplants can restore vision if cloudiness becomes severe. Medications can help control triglyceride levels. Research into gene therapy and enzyme replacement continues, but these treatments are not yet available for this condition.