This week’s blog on Paediatric Cataract has been contributed by Dr Syed M. Asad Ali, Consultant Paediatric Ophthalmologist, Strabismus and Cataract Surgery
What is Cataract?
Cloudiness or opacity in the natural crystalline lens of the eye is called cataract. It is also called ‘white water’ or ‘white pearl’ because of its white appearance. Cataract is very common in people over the age of 50 but – contrary to common belief – it can happen at any age. When a child is born with a Cataract it’s called Congenital Cataract and it affects the vision by preventing all the light reaching the retina at the back of the eye.
Causes of Cataract in the young
Cataract can occur in one eye (unilateral) or both eyes (bilateral). In Western countries, the incidence of Cataract affecting childhood vision is about 3-4 cases in 10,000 live births. The incidence is higher in Asia.
Bilateral Cataracts can be caused by genetic mutations; over 15 gene defects have now been discovered. There are also systemic associations with metabolic disorders such as galactosemia, Wilson disease and diabetes. It has been noticed in people with Trisomy 21 (down syndrome) as well. If a mother acquires an infection such as rubella, herpes, toxoplasmosis or syphilis, this can cause Cataracts at birth.
Unilateral Cataracts are sometimes associated with other eye diseases like small eye, abnormal front of the eye (anterior segment dysgenesis), inflammation, vitreous and retinal diseases.
Any significant trauma (impact with a sharp or blunt object) to the eye can cause Cataract.
Presentation
At a very early age, parents may notice a white area at the centre of the pupil or an abnormal reflection in the pupil. Some children develop squint due to lazy eye caused by Unilateral Cataract. Children are sometimes brought to the ophthalmologist after failing a school eye test. In the case of Unilateral Cataract, even older children may not realise that they are only seeing with one eye, as they are able to manage well.
Treatment
Treatment of Cataracts depends on a number of factors like age at diagnosis, presence of Unilateral or Bilateral, mild or dense cataract and the presence of lazy eye. Dense Bilateral Cataracts at birth are operated on at around 6-8 weeks of age because early surgery can pose a high risk of Glaucoma (blue water) and delaying surgery beyond 3 months of age can limit the vision improvement, due to the development of lazy eyes. Unilateral Dense Cataract at birth has a poor visual prognosis because of the early development of lazy eye.
Mild Cataracts do occur but significant Cataract treatment involves surgery and the removal of the Cataract. In children under 3-4 years of age, Cataract removal also removes the part of front jelly (vitreous) of the eye.
An intraocular lens (IOL) is usually implanted in children above 1 year of age but this can be done earlier in unilateral cases. The power of the IOL selected also allows for the growth of the eye.
After surgery care is very important and may involve regular eye drops for 4-6 weeks after surgery, regular wearing of glasses, contact lenses and patching (covering the one eye with better vision) for the prescribed number of hours. This requires a lot of support and involvement of the parents
In these cases, early diagnosis and prompt treatment can save children from lifelong sight impairment.
It is important for all children to have regular eye check-ups.
Glaucoma is an increase in pressure inside the eye and is a potentially blinding condition in childhood. Glaucoma has many potential causes.
Our eyes are filled with a fluid-like substance called aqueous humor, which moves around the eye and drains through tiny passages.
In children, the most common cause of Glaucoma is congenital malformation of these passages during the formation of the eye in the mother’s womb.
Testing your child for Glaucoma
Detecting Glaucoma at an early stage can prevent vision loss. All newborns, soon after birth, undergo a baby wellness check, which includes examining the eye for the presence of red reflex and to test the clarity of the cornea.
What is the cornea and red reflex?
The cornea is like the windshield of a car – if the windshield is clear, we are able to see very well. When the eye pressure increases, the cornea becomes cloudy and the red reflex is not seen. Red reflex can also be dull or absent in the presence of cataract or clouding of the lens. Both of these conditions require urgent intervention.
My child’s eyes are big! Should I be worried?
In many cultures, big eyes are a sign of beauty but unfortunately it is also one of the signs of developing Glaucoma. Since the fluid is trapped inside the eye and cannot drain properly, the eye gradually increases in size, just like filling a balloon with air makes it bigger. This increase in the size of the eye can damage the optic nerve at the back of the eye and which is the main nerve involved in vision.
What are the signs of Congenital Glaucoma?
- Large eyes
- Cloudy corneas
- Unequal size of eyes
- Constant watery or teary eyes
- Sensitivity to bright lights (‘Photophobic’)
Can Glaucoma be treated?
Yes, Congenital Glaucoma can be treated either medically or surgically. The success of any treatment depends on how early the treatment starts.
Who treats Glaucoma?
A trained Consultant Ophthalmologist with experience in dealing with Congenital Glaucoma should lead the treatment. It’s a condition that requires lifelong monitoring and treatment.
Traditionally, the aim of cataract surgery has been to give patients the quality of vision to ensure a normal lifestyle including distance vision activities such as driving and watching movies. For clear near vision after cataract surgery, patients would often still require glasses for reading.
Nowadays, candidates for cataract surgery have a wide range of options, including multifocal IOLs (Intraocular Lenses) that offer total vision correction.
If you need cataract surgery and want more freedom from spectacles after surgery, then multifocal intraocular lenses are an excellent option to increase your range of clear vision. In fact, many people who choose multifocal intraocular lenses are generally glasses-free or may only need reading glasses occasionally for reading small print, after cataract surgery.
Who are the best candidates for multifocal IOLs?
If you are considering having a multifocal IOL implant, it’s important to understand that they also have their limitations.
If you are in a job that needs you to have the best possible distance vision at all times, or excellent night vision – for example if you are a pilot or someone who does a lot of night driving – then you probably are not a good candidate for multifocal IOL implants and regular monofocal (single-focus) lenses would be a better choice and provide very good distance vision. This would mean that you would need reading glasses to see well, up close.
Another thing to keep in mind is that if you have an associated visual condition other than a cataract (such as diabetic retinopathy, glaucoma or age related macular degeneration), you would be more satisfied with the results using regular monofocal IOLs. This is because multifocal IOLs need good visual capability in both eyes for optimal results.
Other considerations
To get the best visual results with multifocal IOLs, the exact placement of the lens in the eye is very important.
So, a cataract surgeon may also recommend a laser cataract surgery procedure using a femtosecond laser to help ensure accurate positioning of the multifocal IOL and get the best possible results from the lens.
Diabetes is a disease related to the body’s inability to properly absorb, store and use sugar from food. This results in higher levels of sugar in the blood (hyperglycaemia).
Differences between type 1 and type 2 diabetes
Type 1 diabetes is often referred to as ‘insulin dependent’ and is mostly diagnosed in children or young adults. Type 2 diabetes is the most common type; it usually appears in adults over the age of 40 and is often related to overweight, obesity and lack of physical activity in people who are genetically predisposed.
Genetic predisposition affects people differently, depending on the type:
- In type 2 diabetes, if one parent is affected the risk of transmission to children is about 40%, which increases to 70% if both parents have the disease.
- In type 1 diabetes, the risk is much lower, being only 5%.
Diabetes is a significant public health issue in the region, with the UAE, Saudi Arabia, Bahrain, Kuwait all featuring in the top 15 countries in terms of the prevalence of diabetes worldwide. According to data from The Institute for Health Metrics and Evaluation from 2015, 19.3% of the UAE population between the ages of 20 and 79 have type 2 diabetes, which is almost 1 in 5 people, meaning that there are over 1 million people living with diabetes in the UAE. In the UAE, diabetes is also among the top seven causes of premature death and is 4th among the top causes of disability; diabetes increased by a staggering 174% between 2005 -2015.
Type 2 diabetes can sometimes be difficult to diagnose, as it is often painless and without symptoms, at least at the beginning. In fact, it is estimated that the interval between the first appearance of hyperglycaemia and the diagnosis of diabetes is around 5 to 10 years.
Prolonged and repeated hyperglycaemia leads ultimately to the damage of blood vessels and nerves throughout the body, and this includes complications in the eyes, kidneys, heart, brain and limbs.
Diabetic Retinopathy
Diabetic Retinopathy is one of the most common and serious complications of diabetes and its prevalence increases with the amount of time diabetes is present, with age, poor control of blood sugar, blood pressure, cholesterol and lipids.
Although some visual problems can indicate the presence of Diabetic Retinopathy (such as blurred letters when reading, vision difficulties when moving from light to dark) more commonly the disease starts in a completely silent way with no obvious symptoms.
Diabetic Retinopathy can be present even in patients with excellent visual acuity and no symptoms, and can only be diagnosed by the ophthalmologist with a Fundus examination. Sometimes, additional tests are required, such as OCT and Fluorescein Angiography to evaluate the risk of the progression of retinopathy. Some early cases can be just observed, whilst more advanced cases require active management.
Diabetic Retinopathy Treatment
Different treatment options are available, and sometimes a combination of the possible treatments is used. These include intravitreal injection of medications (anti VEGF and or steroids), conventional peripheral laser, subthreshold micropulse laser. In more advanced cases, with prolipherative retinopathy or with intravitreal haemorrhages, surgery may be the only possible option.
Early diagnosis of the complications of diabetes generally leads to better management and better outcomes, and that is why it is vitally important to make regular visits to the ophthalmologist.
This blog on Keratoconus has been contributed by Dr Osama Giledi, Consultant Ophthalmologist, Specialist in Cataract, Cornea and Refractive Vision Correction Surgery
What is Keratoconus?
The word Keratoconus comes from two Greek words: kerato (cornea) and konos (cone). Keratoconus is a degenerative disorder of the eye in which the shape of the cornea, which is usually round, is distorted and develops a cone-shaped bulge, resulting in reduced vision. Keratoconus is a relatively common condition. It affects one person in two thousand, occurs around the world and is quite common in the Middle East.
Progression of Keratoconus depends on the patient’s age at the time of onset and the severity of eye rubbing. The earlier the onset, the faster Keratoconus may progress. The condition always affects both eyes and is asymmetric, so one eye may be more affected than the other.
Causes
Keratoconus has many causes, and it results in a cornea that is more elastic than normal and that starts to thin and bulge forward, causing reduced vision and increased astigmatism. It can be inherited, and a chromosomal link has been identified. Keratoconus can be associated with other allergic diseases such as hay fever, eczema and asthma but we are not born with it, and its onset usually happens around puberty. It is strongly associated with eye rubbing, making it progress rapidly. It is also seen in contact lens wearers.
For the best outcome, Keratconus should be detected and treated early. Early detection is possible by generating computerized corneal shape and thickness measurements through corneal topography using advanced technology such as a pentacam machine. If left untreated, Keratoconus could lead to significant visual impairment and blindness.
Treatment
Spectacles
These can provide good vision in the early stages of the condition and usually help to correct myopic astigmatism.
Hard or Scleral Contact Lenses
When spectacles don’t work, rigid contact lenses and Scleral lenses usually provide very good vision if the patient can tolerate them; they should be fitted by a contact lens specialist.
CXL – Corneal Collagen Cross linking with Riboflavin (Vitamin B2)
This technique increases the strength of the cornea and prevents the progress of Keratoconus.
Intracorneal Rings (Intacs & Ferrara)
These rings inserted into the cornea change the shape of the corneal cone, flattening it and making it a more regular and central shape. This will help improve the vision for the majority of patients.
We use it when patients cannot tolerate contact lenses and while the cornea is still clear and the condition is not very advanced. A Femto-second laser is used to create the tunnel and the entry point for the rings, making it a very safe and reliable procedure.
Toric Implantable Contact Lenses
For those with stable Keratoconus and good vision with glasses, Toric Implantable Contact Lenses are generally used (sometimes after stabilizing the Keratoconus with corneal cross linkage) to improve corneal shape with an intracorneal ring or with very limited therapeutic Excimer laser correction. The Toric ICL can eliminate the need for optical aids altogether and, in some patients, results in improved vision and balance between the two eyes.
Phototherapeutic Keratectomy (PTK)
Keratoconus patients are not candidates for Lasik or normal laser correction. However, some patients benefit from limited excimer laser correction to improve the surface irregularity of the cornea when
contact lenses cannot be tolerated. PTK is always combined with corneal cross-linkage, undertaken during the same procedure or afterwards.
Corneal Transplants
Corneal Transplants are used in the advanced stages of Keratoconus, when there is corneal scarring. The procedure is either a partial thickness (Deep Anterior Lamellar Keratoplasty = DALK) or full thickness graft (Penetrating Keratoplasty = PK). The need for corneal grafts is declining because of the increasing success in the early diagnosis of Keratoconus and the effectiveness of corneal cross linkage to stabilize the condition, so Keratoconus generally does not reach the advanced stage.
Uveitis is not a single disease but a clinical spectrum of symptoms and signs caused by a variety of medical conditions. Although it accounts for about 1% of all eye diseases, Uveitis is the cause of 10-15% of blindness, thus, it must be managed very carefully. Prompt and appropriate treatment is needed to ensure good visual recovery, which is very often achievable. In most cases, a Uveitis specialist – an eye doctor with specialist training in diagnosing and managing these diseases – should manage Uveitis.
Uveitis can affect children, especially those with childhood arthritis or infections. Uveitis affects young adults of a working age and more often women are affected. Symptoms include red eye (although in children the eyes do not become red, so if diagnosed with arthritis, they must have regular screening with the Uveitis specialist), pain, light sensitivity, and blurred vision. It may be associated with skin rashes, joint pains, and stomach symptoms.
What cause Uveitis?
The cause of Uveitis can be infection (like TB, Toxoplasmosis or viruses like herpes and CMV) or autoimmune conditions (sarcoidosis, arthritis, inflammatory bowel disease). In about half of the cases, we may never find a specific cause but prompt treatment is always needed.
Initially, patients will often need to have a variety of blood tests to look for infection or auto immune conditions, chest x-rays and other imaging. In the eye clinic patients may need an OCT scan of the retina and a flurosein angiogram to look for leakage from the blood vessels in the retina. Patients may also be referred to othzer specialists like rheumatologists, gastroenterologists or neurologist to help diagnose a systemic cause of the Uveitis.
What is the treatment for Uveitis?
Uveitis can be in the anterior segment (front part of the eye), which usually can be treated with drops and sometimes injections to get a quick response. When Uveitis affects the back of the eye, more aggressive treatment may be needed. This usually consists of a high dose of oral steroid medications for several weeks. Antibiotics are given in case of infection. Long-term treatment or more serious cases may need steroid sparing immune suppressant medication. This scan be in the form of tablets like mycophenolate or methotrexate or newer biologic medications, which are given in the form of injections. Steroid injections into the eye may be needed as well. Although protracted, early, aggressive and appropriate treatment can achieve good control of this condition and patients can maintain good vision.
What are the complications of Uveitis?
Complications of Uveitis include cataract, high pressure in the eye and macular oedema. These may need additional treatment including surgery.
If you have been diagnosed with Uveitis or suspect that you may have Uveitis, it is essential to see a Uveitis specialist