The term ‘corneal disease’ is used to describe a range of conditions affecting the cornea including injuries, infections, allergies, and inherited disorders. Here we expand on five common conditions that are routinely managed by David Gartry:
Keratoconus (derived from the Greek term for ‘cone-shaped cornea’) – a condition that usually affects both eyes in which the cornea weakens, thins and develops a cone-like outward bulge. It is caused by a fault in collagen production, a protein that provides the building blocks of the cornea. It is part of a larger group (>20) of ‘degenerations and dystrophies’ that change the transparency of the cornea through structural faults and the buildup of cloudy material. They require individual and tailored treatment as they affect vision and comfort in very different ways.
Who is affected? It is estimated that Keratoconus affects between 1 in 500 and 1 in 2000 individuals. The condition is usually diagnosed in teenagers and young adults. There can be a family history of the condition. It also presents more frequently in people of Asian and Mediterranean origin, and those with allergies like asthma or eczema.
What are the symptoms? Most people with Keratoconus experience blurred or distorted vision. The changing shape of the cornea as it weakens, thins and bulges outwards, causes it to resemble more of a rugby ball or back of a spoon than a round football. As light passes through, some parts bend more than others splitting the focus into two separate points at the back of the eye. This is termed ‘astigmatism’, and is a type of refractive error that also occurs commonly in healthy eyes. However, eyes affected by Keratoconus have a higher level and complexity of astigmatism, which usually occurs in combination with ‘shortsightedness’ causing a more severe reduction in vision.
How can it be treated? There is no cure for the condition, but there are ways to improve vision by correcting the astigmatism and short-sightedness. Spectacles or readily available ‘soft’ contact lenses are prescribed in early stages. As the condition progresses, specially-made ‘hard’ contact lenses may be required to better correct the abnormal shape of the cornea and improve the quality and stability of vision. Some people with stable Keratoconus can benefit from a relatively new treatment called ‘Corneal Crosslinking’, in which a type of UV light is used with vitamin B2 (riboflavin) eye drops to strengthen the cornea and slow down the disease process. In most cases, the change in corneal shape naturally slows after a few years without major impact on vision. However, David may need to perform corneal transplant or ‘graft’ surgery in advanced cases where the central cornea becomes swollen and scarred, or when a person is unable to tolerate contact lenses. This operation is successful in improving vision quality in the vast majority of cases, usually in combination with spectacles or contact lenses worn after surgery.
2. Abrasions & ‘recurrent corneal erosion’ (RCE)
Abrasion (scratch) or injury of the cornea that affects surface layers usually heals within 24-48 hours, as new cells migrate to fill and smooth the affected area. In some cases, these cells are unable to attach properly to underlying corneal layers preventing the wound from healing completely. The area of weakened cells form a blister which can wear or peel away spontaneously as it rubs against the inner eyelid, often repeatedly for months or years after the initial injury. This is better known as Recurrent Corneal Erosion (RCE).
Who is affected? Eye trauma accounts for approximately 3% of all emergency department visits. Of these, the vast majority are caused by foreign bodies and corneal abrasions (usually by objects like fingernails and branches). They can affect anyone but tend to occur more frequently in people of working age who are at greater risk of injury during the course of their day. RCE is estimated to occur in 1 in 150 cases of corneal abrasion but it can also happen in the absence of trauma, for example following corneal surgery, or when a person has a degenerative or inherited condition such as Basement Membrane Dystrophy (a condition that affects the outer layer of the cornea, in which abnormal development of the membrane beneath prevents it adhering properly).
What are the symptoms? The cornea has the most densely packed nerve endings of any other part of your body. This means that even a minor, surface abrasion or RCE can cause significant pain and tearing, often with increased sensitivity to light and temporary reduction in vision depending on the area affected. RCE episodes typically happen when the eye surface dries during the night or on waking in the morning. The pain tends to lessen over the next 24 to 72 hours as the cells gradually heal.
How can it be treated? The cornea has a remarkable ability to repair itself. This means that most minor abrasions when treated in a timely and appropriate manner, heal within 24 to 72 hours without developing infection or RCE:
- – Antibiotic eye drops – to prevent infection depending on the severity and extent of the injury
- – Artificial lubricant eye drops – commonly used to form a protective barrier between the corneal surface and eyelid, aiding healing and providing comfort
- – Oral medications – to relieve pain where necessary
Management of RCE is focussed on prevention through the long-term use of lubricating eye drops and ointments. Where conventional management fails to prevent recurring episodes or in eyes at risk of permanent vision loss and scarring, David will recommend alternative therapies such as:
- – A ‘bandage contact lens’ – to form a protective barrier between the blister of weakened cells and inner eyelid
- – Laser therapy or surgery – to remove weakened cells and encourage healthy cells to adhere to underlying corneal cells and heal more completely (see PTK)
Advanced cases of trauma that can affect the cornea, iris (coloured part of the eye) and even the crystalline lens may require more complex surgical intervention and reconstruction by David.
3. Dry eye
Dry eye is a common condition affecting 1 in 4 people in the UK in which your natural tears are unable to cover the eye surface adequately, causing it to dry and sometimes become inflamed. Most people who work in an air-conditioned office and spend long hours staring at a computer screen will have experienced ‘dry eye’ at some stage.
Who is affected? Dry eye affects people of any age, but the chances of developing the condition are higher among older people, women experiencing hormone changes and those who use certain medications. The condition can also occur after certain types of laser surgery, but it is usually self-limiting as damaged nerves regenerate over the coming weeks to months.
What are the symptoms? Symptoms can range from mild redness and irritation to grittiness, burning and foreign-body sensation (a phantom sensation of ‘something in the eye’). Some people also report watery eyes known as ‘reflex tearing’, where our eyes overproduce tears in an attempt to alleviate dryness. In some cases, vision can be temporarily affected as the drying tear layer creates the illusion of looking through a frosted window in between eye blinks.
How can it be treated? David and our specialist optometrists will advise you on simple steps you can take to prevent or reduce the effects of dry eye, from treatment of glands along your eyelids to making changes to your diet (e.g. increasing Omega 3 levels to improve tear quality) and room environment. They will also recommend individual or combination artificial tear drops, gels, and ointments to alleviate your symptoms. For more advanced cases, David will formulate a tailored plan that can include additional therapies to improve your tear quality and volume.
4. Fuchs Dystrophy
Fuchs Dystrophy is a common age-related cause of cloudy cornea that is part of a larger group (>20) of ‘degenerations and dystrophies’ that lead to a loss in transparency. It is caused by fluid build-up in the cornea as the innermost layer loses the ability to pump out excess fluid.
Who is affected? Fuchs dystrophy occurs in approximately 4 in 100 people, with higher numbers affected in European countries relative to other areas around the world. It is usually diagnosed in people aged 50 years and older, and affects 2-4x more females than males. Other risk factors of developing the condition include heavy smoking and a family history of the condition.
What are the symptoms? In early stages, the most common complaint is painless blurring of vision in both eyes, which tends to be worse on waking in the morning as the cornea swells overnight. This can occur with increased sensitivity to bright light and the perception of glare/ haloes around light sources. The change in corneal shape and thickness can also affect the focusing power of the eye, making it temporarily more short-sightedness. All visual symptoms usually improve over the course of the day as the cornea dehydrates. As Fuchs dystrophy advances, it can cause pain and severe impairment of vision.
How can it be treated? Corneal swelling can be reduced by using dehydrating eye drops and ointments, and applying warm air to the eye surface using a hair dryer or alternative. As the condition worsens, a bandage contact lens may be worn to improve comfort. If the vision continues to deteriorate, a transplant (graft) may be needed to replace the damaged cornea with healthy donor tissue.
Pterygium is a pink-white triangular growth that begins at the edge of the cornea, and gradually grows inwards towards the centre.
Who is affected? Pterygium is more common in people who have lived in sunny and dry climates, and in particular, among those who have spent more time outdoors without protecting the eyes against UV light.
What are the symptoms? As pterygium encroaches across the cornea, it can alter the shape so that the surface resembles more of a rugby ball or back of a spoon than a round football. As light passes through, some parts bend more others splitting the focus into two separate points at the back of the eye. This is termed ‘astigmatism’, and usually presents as distorted or blurred vision that can be corrected using spectacles or contact lenses. The raised growth can also impair the natural flow of tears across the eye surface causing dryness, redness, and irritation.
How can it be treated? In early stages, eye comfort can be improved using artificial lubricant eye drops and ointments. Surgical intervention is only necessary if the pterygium advances, causing a permanent reduction in vision, long-term discomfort that cannot be managed using conventional means, or to improve how the eye looks.