Corneal Disorders & Transplantations
Fig: Different Layers of Cornea (taken from: https://gene.vision/knowledge-base/corneal-dystrophies-for-patients/)
In this article you will find information about the following:
1. Gist of various corneal disorders we treat regularly.
2. What are different types of Corneal Transplantations?
3. What are the risks involved with corneal transplantation?
4. What happens if my corneal transplant fails or stops working?
5. Do I need lifelong steroids for Corneal transplantation?
6. Is there a need for oral steroids in Corneal transplantation?
7. What are the side effects of oral steroids?
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Here is a gist of various Corneal Disorders we treat regularly.
The cornea is the transparent, dome-shaped outermost layer of the eye, responsible for refracting light and protecting the inner structures. Various corneal disorders can affect its clarity, shape, and function. Here's a gist of some common corneal disorders:
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Corneal Abrasion: A scratch or injury to the cornea, often caused by foreign objects or trauma, leading to pain, tearing, and sensitivity to light.
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Corneal Ulcer: An open sore on the cornea, usually caused by infection (bacterial, viral, or fungal), leading to severe pain, redness, and potential vision loss.
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Keratitis: Inflammation of the cornea, which can be infectious (caused by microbes) or non-infectious (due to injury, contact lens overuse, or underlying conditions).
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Keratoconus: A progressive condition where the cornea becomes thin and bulges into a cone shape, causing astigmatism, near-sightedness, and distorted vision.
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Fuchs' Dystrophy: A degenerative disorder of the corneal endothelium, leading to fluid accumulation and swelling, resulting in hazy vision, glare, and pain.
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Corneal Oedema: Generalized swelling of the cornea due to fluid accumulation, often as a result of an underlying condition or previous eye surgery.
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Herpes Simplex Keratitis: A viral infection caused by the herpes simplex virus, leading to painful corneal sores, redness, and tearing.
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Corneal Degeneration: Various conditions, such as band keratopathy and Salzmann nodular degeneration, that cause non-inflammatory deposits or changes on the cornea's surface, affecting vision.
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Corneal Dystrophies: Inherited disorders leading to abnormal deposits in the cornea, such as lattice dystrophy and granular dystrophy.
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Pterygium: A growth of conjunctival tissue onto the cornea, usually caused by UV exposure, leading to redness, irritation, and potential vision obstruction.
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Corneal Ectasia: A condition in which the cornea progressively thins and bulges, often occurring after laser eye surgery (LASIK or PRK).
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Neurotrophic Keratitis: A rare condition caused by damage to the corneal nerves, leading to reduced corneal sensation, poor healing, and potential ulcers.
It's essential to seek prompt medical attention if you experience any symptoms related to corneal disorders, as early diagnosis and treatment are crucial for preserving vision and preventing complications.
Fig: Types of corneal transplantation. ( Courtesy: https://jamanetwork.com/journals/jama/fullarticle/2779225 )
What are different types of Corneal Transplantations
Corneal transplantation, also known as corneal grafting or keratoplasty, is a surgical procedure used to replace a damaged or diseased cornea with a healthy donor cornea. There are several types of corneal transplants, each designed to address specific corneal conditions. The main types of corneal transplants include:
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Penetrating Keratoplasty (PKP): This is the traditional and most common type of corneal transplant. It involves replacing the entire thickness of the central cornea with a donor cornea. PKP is used for conditions like advanced keratoconus, corneal scarring, and corneal dystrophies.
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Deep Anterior Lamellar Keratoplasty (DALK): DALK involves replacing the anterior layers of the cornea, leaving the patient's healthy corneal endothelium intact. It is used when the innermost layer of the cornea, the endothelium, is healthy, but the outer layers are diseased or scarred.
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Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK): This procedure targets only the innermost layer of the cornea, called the endothelium. A thin layer of the patient's diseased endothelium is removed and replaced with a donor's healthy endothelial tissue. DSAEK is commonly used for Fuchs' endothelial dystrophy and some cases of corneal edema.
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Descemet's Membrane Endothelial Keratoplasty (DMEK): Similar to DSAEK, DMEK targets the corneal endothelium. However, in DMEK, only the Descemet's membrane and endothelium are transplanted, providing faster visual recovery and lower rejection rates compared to DSAEK.
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Keratoprosthesis (Artificial Cornea): In cases where traditional corneal transplants are not feasible due to multiple failed grafts or severe ocular surface diseases, a keratoprosthesis can be implanted. It is an artificial cornea made of biocompatible materials.
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Patch Grafts: In some cases, rather than replacing the entire cornea, a small patch of donor tissue is used to repair a specific corneal defect, such as a corneal perforation.
The choice of corneal transplant technique depends on the individual patient's condition, the extent of corneal damage, and the surgeon's expertise. Corneal transplants have a high success rate, but like any surgical procedure, there are risks and potential complications. Close post-operative care and compliance with the prescribed medications are essential for successful outcomes.
What are the risks involved with corneal transplantation?
Corneal transplantation, like any surgical procedure, carries certain risks and potential complications. While corneal transplants have a high success rate, it's important to be aware of the possible risks involved. Some of the risks include:
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Graft Rejection: The recipient's immune system may recognize the transplanted cornea as foreign and attempt to reject it. This risk is highest in the first year after surgery but can occur at any time. The risk of rejection varies from the type of transplantation being done. With PKP the risk is around 20%, with DALK the risk is around 10% and with DSAEK/DMEK the risk is less than 10%. Rejection can lead to corneal swelling, inflammation, and vision deterioration. Prompt medical attention is crucial if signs of rejection are detected.
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Infection: Infection is a potential risk after corneal transplantation ( 1-5%) , especially in the early post-operative period. Infections can be bacterial, viral, or fungal and may lead to corneal damage or graft failure if not treated promptly. Endophthalmitis (the most severe form of infection) risk is rare, around 0.8-2 in 1000.
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Graft Failure: In some cases, the transplanted cornea may not properly integrate or heal, leading to graft failure. The overall incidence of graft failure after corneal transplantation is approximately 5% to 20%. This can be due to various factors, including graft rejection, infection, and wound healing complications.
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Astigmatism: After corneal transplantation, the cornea's shape may be altered, leading to astigmatism (irregular curvature of the cornea). Astigmatism can cause blurry or distorted vision.
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Glaucoma: Corneal transplantation can increase the risk of developing glaucoma in about 10-20% of cases, a condition where increased intraocular pressure damages the optic nerve and affects vision.
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Cataracts: In some cases (10-30%), cataracts may develop after corneal transplantation, especially if the eye had pre-existing cataracts or if the surgery involves the lens.
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Persistent Swelling: occurs in 5-20% of cases. Inflammation or persistent corneal swelling (corneal oedema) can occur, affecting visual recovery.
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Suture Complications: If sutures are used to secure the transplant, there is a risk of suture-related complications, such as infection or suture-related astigmatism.
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Delayed Visual Recovery: While many patients experience improved vision after corneal transplantation, it may take several weeks to months for the vision to stabilize and reach optimal levels.
It's important for patients considering corneal transplantation to discuss these potential risks and complications with their ophthalmologist. Additionally, adhering to post-operative care, using prescribed medications, and attending regular follow-up appointments are essential for monitoring and managing any issues that may arise. With proper care and monitoring, most corneal transplants are successful in restoring vision and improving quality of life for patients with corneal disorders.
What happens if my corneal transplant fails or stops working?
If your corneal transplant stops working or if there are signs of graft failure, it is essential to seek immediate medical attention from your ophthalmologist or corneal specialist. Graft failure can occur due to various reasons, such as graft rejection, infection, complications with the donor tissue, or other underlying issues.
Here are the steps you should take if you suspect your corneal transplant is not functioning properly:
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Contact Your Eye Doctor: If you notice any sudden changes in vision, increased eye redness, pain, or discomfort, contact your corneal specialist/ eye doctor immediately. They will be able to assess your condition and determine if there is an issue with your corneal transplant.
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Follow Medical Advice: Your eye doctor will conduct a thorough examination to identify the cause of the graft failure. Depending on the underlying issue, they may recommend specific treatments or interventions to address the problem.
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Manage Graft Rejection: If graft rejection is suspected, your doctor may prescribe immunosuppressive medications to suppress the immune response and prevent further damage to the transplant. It is crucial to follow the prescribed medication regimen diligently.
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Treat Infections: In the case of infection, appropriate antimicrobial medications will be prescribed to control the infection and prevent it from causing further damage to the transplant.
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Monitor Progress: Regular follow-up visits will be necessary to monitor the progress of your condition and assess how well the transplant is functioning. Your doctor will adjust the treatment plan as needed based on your response to therapy.
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Consider Revision Surgery: In some cases of graft failure, if the transplant cannot be salvaged, your doctor may recommend a revision corneal transplant or another suitable treatment option, depending on your specific situation.
It's important to remember that not all cases of graft failure are permanent, and prompt medical attention can make a significant difference in the outcome. Regular follow-up care and compliance with the prescribed medications are crucial to achieving the best possible results and maintaining the health of the corneal transplant.
Keep in close communication with your eye doctor, and do not hesitate to reach out if you have any concerns about your corneal transplant or your vision. They are the best resource to address any issues and provide appropriate guidance for your individual case.
Do I need lifelong steroids for Corneal transplantation?
The need for lifelong steroids after corneal transplantation depends on several factors, including the type of corneal transplant performed, the risk of graft rejection, and the individual patient's response to the surgery. Steroids are commonly prescribed after corneal transplantation to help reduce the risk of graft rejection and control inflammation in the eye.
Here are the common scenarios regarding the use of steroids after corneal transplantation:
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Penetrating Keratoplasty (PKP): For traditional full-thickness corneal transplants like PKP, patients are typically prescribed topical steroids after surgery. The dosage and duration of steroid use can vary, but some patients may be on a tapering regimen that gradually reduces the steroid dose over several months.
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Deep Anterior Lamellar Keratoplasty (DALK): Patients who undergo DALK may also receive topical steroids after surgery to reduce inflammation and the risk of rejection. However, since the innermost layer of the cornea (the endothelium) is not replaced in DALK, the long-term steroid use may be shorter compared to PKP.
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Endothelial Keratoplasty (DSAEK/DMEK): In these procedures, which target only the inner layers of the cornea, the risk of rejection is lower. However, steroids are still prescribed initially to control inflammation, but the duration of their use may be relatively shorter compared to full-thickness transplants.
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High-Risk Cases: In certain high-risk cases, such as multiple previous graft failures or other conditions that increase the risk of rejection, the use of steroids may be prolonged or even continued on a maintenance basis for a longer duration.
It's essential to follow your Corneal Specialist’s instructions regarding the use of steroids after corneal transplantation. Abruptly stopping or reducing the prescribed steroid dosage without medical guidance can increase the risk of graft rejection or other complications.
Long-term steroid use may have potential side effects, such as increased intraocular pressure (glaucoma) or cataract formation. Your Ophthalmologist will monitor your eye health regularly and adjust the treatment plan as needed to balance the benefits of using steroids with the potential risks.
As with any medical treatment, communication with your eye doctor is crucial. If you have concerns or questions about the medications prescribed after your corneal transplantation, discuss them with your ophthalmologist to ensure the best possible outcome for your eye health.
Is there a need for oral steroids in Corneal transplantation?
The use of oral steroids in corneal transplantation is relatively uncommon, but there are specific situations where they may be considered. Oral steroids are systemic medications that can have more widespread effects throughout the body, including the eyes. They are generally reserved for certain high-risk cases or when there is a need to manage significant inflammation or immune response beyond what topical steroids can provide.
Here are some situations where oral steroids might be used in corneal transplantation:
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High-Risk Grafts: In cases where the corneal transplant is considered high-risk for rejection, such as repeat grafts or complex cases, oral steroids may be prescribed in addition to topical steroids. This approach aims to provide a more potent anti-inflammatory effect to reduce the risk of graft rejection.
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Severe Inflammation: If the patient experiences severe inflammation or a robust immune response following corneal transplantation, oral steroids may be considered as an additional measure to control the inflammation and promote graft survival.
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Steroid-Resistant Rejection: In some cases, graft rejection may not respond adequately to topical steroids alone. In such situations, oral steroids can be used to help suppress the immune response and prevent further damage to the transplant.
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Underlying Systemic Conditions: If the patient has certain systemic conditions that affect the immune system, such as autoimmune diseases, the use of oral steroids may be necessary to manage both the systemic condition and the risk of graft rejection.
It's important to note that oral steroids come with a higher risk of systemic side effects compared to topical steroids.
The decision to use oral steroids in corneal transplantation is made on a case-by-case basis, weighing the potential benefits against the risks. If your eye doctor determines that oral steroids are necessary for your specific situation, they will closely monitor your health and adjust the dosage and duration of treatment as needed.
As with any medical treatment, it's essential to have open communication with your eye doctor and follow their recommendations carefully to achieve the best possible outcome for your corneal transplantation and overall eye health.
What are the side effects of oral steroids?
Oral steroids, also known as systemic corticosteroids, are powerful medications that have anti-inflammatory and immunosuppressive effects on the body. While they can be effective in treating various medical conditions, they also come with a range of potential side effects, especially when used for extended periods or at high doses.
Here are some of the side effects associated with oral steroids:
Most Common Side Effects:
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Weight Gain
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High Blood Pressure
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Increased Blood Sugar Levels (Steroid-Induced Diabetes)
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Mood Changes (Including Mood Swings, Irritability)
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Immune Suppression
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Skin Changes (Skin Thinning, Increased Bruising)
Common Side Effects:
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Cataracts (Steroid-Induced Cataracts)
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Osteoporosis (Bone Weakening)
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Muscle Weakness
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Fluid Retention (Edema)
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Gastrointestinal Issues (Stomach Irritation, Ulcers, Bleeding)
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Glaucoma (Steroid-Induced Glaucoma)
Less Common Side Effects:
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Increased Infection Risk
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Menstrual Irregularities (In Women)
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Adrenal Suppression
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Delayed Wound Healing
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Mood Changes: Oral steroids can lead to mood swings, irritability, and even psychological disturbances, such as anxiety, depression, and euphoria.
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Weight Gain: Steroids can cause fluid retention and increased appetite, leading to weight gain. This weight gain is often most noticeable in the face, abdomen, and neck ("moon face" and "buffalo hump").
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High Blood Pressure: Prolonged use of oral steroids can elevate blood pressure, increasing the risk of hypertension and its associated complications.
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Increased Blood Sugar Levels: Steroids can raise blood glucose levels, potentially leading to steroid-induced diabetes or exacerbating existing diabetes.
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Osteoporosis: Long-term use of oral steroids can weaken bones, increasing the risk of fractures and osteoporosis.
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Muscle Weakness: Steroids can cause muscle weakness and may lead to muscle wasting with prolonged use.
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Cataracts and Glaucoma: Steroids can increase the risk of developing cataracts and glaucoma.
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Immune Suppression: While steroids are used to suppress inflammation, they also suppress the immune system, making individuals more susceptible to infections.
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Increased Infection Risk: Steroids can mask signs of infection, making it challenging to recognize and treat infections promptly.
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Delayed Wound Healing: Steroids can slow down the healing process of wounds and injuries.
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Adrenal Suppression: Prolonged use of oral steroids can suppress the body's natural production of cortisol, the hormone produced by the adrenal glands, which may result in adrenal insufficiency if the steroids are suddenly stopped.
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Gastrointestinal Issues: Steroids can cause stomach irritation, ulcers, and an increased risk of gastrointestinal bleeding.
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Fluid Retention: Steroids may cause fluid retention, leading to swelling in the extremities and exacerbating conditions like heart failure.
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Skin Changes: Steroids can cause skin thinning, bruising, and increased susceptibility to skin infections.
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Menstrual Irregularities: In women, oral steroids may cause menstrual irregularities.
It's crucial to use oral steroids only as prescribed by a healthcare professional and to be aware of the potential side effects. If you are prescribed oral steroids for a medical condition, your doctor will carefully monitor your response and adjust the treatment plan as needed to minimize side effects and achieve the desired therapeutic benefits. If you experience any concerning side effects while taking oral steroids, contact your healthcare provider promptly.
Don't take our word for it!
Reviews from happy patients
C
Mr Rana’s care of me has been excellent. He has explained things very clearly and performed the surgery expertly and quickly. I have complete faith in him and look forward to him continuing to be available to monitor my needs.
S.Q
I would without hesitation recommend Mr Rana. His knowledge & experience of complex corneal conditions is unparalleled. He always seeks to explain options, risks, expected outcomes & timescales. I trust him implicitly to provide the best possible care and outcome for my condition
W.H
Mr. Rana is a Consultant Surgeon with whom I have had the greatest confidence in since our initial interaction a few years ago. He has instilled a lot of confidence in me moving forward with my eye care & I am extremely grateful. I have & would definitely recommend Mr Mrinal Rana