Adult Squint (Strabismus)

About

Adult squint is a misalignment of both eyes and effects about 4% of the adult population

The squint may be present all or only part of the time, in only one eye or alternating between the two eyes.

Adult squints are of three main types: non-paralytic, paralytic and restrictive.

  • Non-paralytic squints: They are usually a longstanding from childhood. The most common pattern is that an eye that was straight after childhood squint surgery later drifts out and causes concern over its appearance.
  • Paralytic squint: The eye does not move normally because one or more eye muscles are weak or paralysed. This problem may have developed as a result of other health problems, such as damage to cranial nerves, following head injury or as a complication of diabetes or stroke. Such people will, most likely, suffer from troublesome double vision.
  • Restrictive squint:  One or both eyes do not move fully because of scarring or tethering of one or more muscles.

Symptoms

Symptoms of adult squint problems include fatigue, double vision, difficulty with near vision and loss of stereo vision. To compensate for this, some individuals will adopt an abnormal head position. Many adults with squint are concerned about the appearance of their eyes and the impact this has on social relationships and work

This information aims to answer some of the questions you may have about squint surgery. However, it does not cover everything as every patient and squint is different. Your surgeon will discuss your particular case with you. Please ask the clinical staff about anything you want to be made clear.

What is the aim of surgery?

  • To improve the alignment of the eyes, to make the squint smaller in size.
  • In some patients, to reduce or try to eliminate double vision.
  • Occasionally to improve an abnormal position of the head.

How is the surgery done?

Squint surgery is a very common eye operation. It usually involves tightening or moving one or more of the outside eye muscles which move the eye. These muscles are attached quite close to the front of the eye under the conjunctiva, the clear surface layer. The eye is never taken out of the socket during surgery. Stitches are used to attach the muscles in their new positions.
Squint surgery is nearly always a day case procedure so you should be in and out of hospital on the same day.
There are two kinds of squint operation – adjustable and non-adjustable:


Non adjustable surgery

The operation is usually carried out under general anaesthetic. The operation usually takes up to 60 minutes depending on the number of muscles that need surgery. When you have recovered from the anaesthetic and the nurses are happy for you to be discharged, you are free to go home – usually a few hours later.


Adjustable surgery

Squint surgery using an adjustable suture may give a better result in certain types of squint e.g. patients who have had a squint operation before, patients with a squint due to injury or patients with thyroid eye problems.

Part 1 – The main operation

The main part of the operation is carried out in the operating theatre usually under general anaesthetic (with you asleep).

Part 2 – Adjusting the stitch

Once you have woken up from the anesthetic the final position of the muscles is adjusted when you are awake and able to look at a target. This is particularly useful for treating double vision. If you wear glasses for distance or near, these will need to be brought in with you for this part of the operation. Adjustment is usually done on the ward, after drops of anaesthetic have been put into the eye to take away any pain. You may however feel a pressure sensation.

Before the day of surgery

A pre-assessment is performed in the weeks leading up to the operation date.


What happens on the day of surgery?

You will be asked to come early so that you can be prepared for surgery. You should not drink or eat before the operation: the exact timings of this will be given before the day of the operation. Before being discharged after the operation, you will receive eye drops with instructions and a follow up appointment.


Does the surgery cure the squint?

Overall about 90% patients feel some improvement in their squint after surgery. The amount of correction that is right for one patient may be too much or too little for another with exactly the same size squint, so that the squint may not be completely corrected by the operation. Although the eyes may be straight just after surgery, many patients require more than one operation in their lifetime. If the squint returns it may drift in either the same or opposite direction. We can’t predict when that drift may occur.


What are the risks of the operation?

Squint surgery is generally a safe procedure. However, as with any operation, complications can and do occur. Generally these are relatively minor but on rare occasions they may be serious.

Under and overcorrection

As the results of squint surgery are not completely predictable, the original squint may still be present (undercorrection) or the squint direction may change over (overcorrection). Occasionally a different type of squint may occur. These problems may require another operation.

Double vision

You may experience double vision after surgery, as your brain adjusts to the new position of the eyes. This is common and often settles in days or weeks but may take months to improve. Some patients may continue to experience double vision when they look to the side in order to achieve a good effect when the eyes look straight ahead. Rarely, double vision whilst looking straight ahead can be permanent in which case further treatment might be needed. If you already experience double vision, you might experience a different type of double vision after surgery. Botulinum toxin injections are sometimes performed before surgery to assess your risk of this.

Allergy/stitches

Some patients may have a mild allergic reaction to the medication they have been prescribed after surgery. This results in itching/irritation and some redness and puffiness of the eyelids. It usually settles very quickly when the drops are stopped. You may develop an infection or abscess around the stitches. This is more likely to occur if you go swimming within the first four weeks after surgery. A cyst can develop over the site of the stitches, which occasionally needs further surgery to remove it.

Redness

The redness in the eye can take as long as 3 months to go away. Occasionally the eye does not completely return to its normal colour, particularly with repeated operations.

Scarring

Most of the scarring of the conjunctiva (skin of the eye) is not noticeable by three months, but occasionally visible scars will remain, especially with repeat operations.

Lost or slipped muscle

Rarely one of the eye muscles may slip back from its new position during the operation or shortly afterwards. If this occurs, the eye is less able to move around and, if severe, further surgery can be required. Sometimes it is not possible to correct this. The risk of slipped muscle requiring further surgery is about 1 in 1,000.

Needle penetration

If the stitches are too deep or the white of the eye is thin, a small hole in the eye may occur, which may require antibiotic treatment and possibly some laser treatment to seal the puncture site. Depending on the location of the hole, the sight may be affected. The risk of the needle passing too deeply is about 2%.

Anterior segment ischaemia

The blood circulation to the front of the eye can very rarely be reduced following surgery, producing a dilated pupil and blurred vision. This usually only occurs in patients who have had multiple surgeries. The risk is about 1 in 13,000 cases.

Infection

Infection is a rare complication but the risk  increases if drops are not instilled as directed and treatment not sought promptly. Significant infection is extremely rare but in the worst cases can cause loss of vision or the eye (endophthalmitis, orbital cellulitis).

Loss of vision

Although very rare, loss of vision in the eye being operated can occur from this surgery. Risk of serious damage to the eye or vision is approximately 1 in 30,000.

Anaesthetic risks

Anaesthetics are usually safe but there are small and potentially serious risks. Unpredictable reactions occur in around 1 in 20,000 cases and unfortunately death in around 1 in 100,000.
Remember: these complications are detailed for your information and that the vast majority of people have no significant problems. After the operation the eye(s) will be swollen, red and sore and the vision may be blurry. The eye may be quite painful.
Start the drops you have been prescribed that evening, and painkillers such as paracetamol and ibuprofen can be taken. The pain usually wears off within a few days. The redness and discomfort can last for up to 3 months particularly with adjustable and repeat squint operations.
You should not sign any legal documents or drive for 48 hours after the general anaesthetic.
We would advise that you may need one or occasionally two weeks off work. Work and normal activities including sport can be resumed as soon as you feel comfortable to do so. It is quite safe to use the eyes for visual tasks, for example reading, watching television. You should return for follow up as advised.


Summary of care after the operation

  • Use the eye drops
  • Use painkillers such as paracetamol and ibuprofen if the eyes are painful
  • Use cooled boiled water and a clean tissue or cotton wool to clean any stickiness of the eyes and avoid water entering the eyes from the bath or shower for the first two weeks
  • Don’t rub the eye(s) as this may loosen the stitches
  • No swimming for 4 weeks
  • Attend the postop clinic appointment
  • Continue using glasses if you have them
  • Avoid contact lens wear in the operated eye(s) until advised it is safe by the doctor or orthoptist

Wasfati – Online Medication Delivery – Abu Dhabi

About

“Wasfati” is a new online medication and prescription delivery service in Abu Dhabi, launched by our sister facilities Danat Al Emarat and HealthPlus Pharmacies. With “Wasfati”, we will deliver your medications to your doorstep!

To avail this service, upload a copy of your prescription and complete the electronic form by visiting: www.wasfati.ae/

Moorfields Dubai Pharmacy

About

For the convenience of our patients, and to better meet their needs, Moorfields Eye Hospital Dubai has an in-house pharmacy within the hospital premises, open 6 days a week during normal hospital hours, and licensed by the Ministry of Health.

From lubricating eye drops to formulating specialty medications in a highly sterile, temperature controlled environment, our team of expert pharmacists are highly qualified and available to happily assist our patients with their customised eye care related medication needs.

Uveitis

About

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 and so 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.


Causes

The cause of uveitis can be infection (like TB, Toxoplasmosis or viruses like herpes and CMV) or autoimmune conditions ( sarcoidosis, arthritis, inflammatory bowel disease etc). In about half the cases, we may never find a specific cause but prompt treatment is always needed.


Symptoms 

Symptoms can include red eye, light sensitivity, loss of reduction of vision, glare, floaters and pain. 


Treatment 

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 in to 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.


Examination

 Clinical examination by a uveitis specialist who will then determine what further testing is needed to establish a cause. About 50% of time, a cause can be identified but all cases require treatment. 


Investigation 

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 fluorescein angiogram to look for leakage from the blood vessels in the retina. Patients may also be referred to other specialists like rheumatologists, gastroenterologists or neurologist to help diagnose a systemic cause of the uveitis.

Retinal Vein Occlusion

About

Blocking of the retinal vein which reduces the vision is known as Retinal Vein Occlusion. This results in the accumulation of blood (retinal hemorrhages) and fluid (macular edema) in the retina and leads to a drop in the visual acuity (clarity of vision).

There are two types of Retinal Vein Occlusion:

  • Central Retinal Vein Occlusion (CRVO)
  • Branch Retinal Vein Occlusion (BRVO)

Causes 

A blockage forms in the vein, usually due to a blood clot, and obstructs the blood flow.  The exact cause is unknown, but several conditions make the condition more likely. These include:

  • High blood pressure
  • High cholesterol
  • Glaucoma
  • Diabetes
  • Smoking
  • Certain rare blood disorders

Symptoms

Retinal vein occlusion sometimes may not have any symptoms. However, some symptoms to observe are:

  • Blurry or missing vision in part or all of an eye
  • Dark spots or lines floating the vision
  • Pain and pressure in the eye

Diagnosis 

Retinal Vein Occlusion is diagnosed clinically with a dilated eye examination. Additional imaging such as fluorescein angiography and ocular coherence tomography (OCT) may be needed to confirm the diagnosis and monitor the progression of the disease.


Treatment

Treatment of Retinal Vein Occlusion includes:

Ocular treatment:

  • Observation if only a small vein is involved and does not affect the macula (central part of the vision).
  • Intravitreal injections of either anti-vascular endothelial growth factor (anti-VEGF) agents or steroid injection to treat the macular edema.
  • Laser photocoagulation may be administered to the peripheral ischemic retina.

Systemic treatment:

  • Management of systemic factors (close control of blood pressure and blood sugar levels).

Retinal Photodynamic Therapy (PDT)

About

Photodynamic therapy (PDT) is a treatment that uses a combination of a “cold” laser and a special light-sensitive dye (Verteporfin). This is injected into the blood stream to target abnormal leaking blood vessels in the retina (nerve tissue lining at the back of the eye which detects light and allows us to see) or the layer below the retina (choroid). PDT is used in the treatment of some specific forms of wet macular degeneration and a disease called ‘Central Serous Retinopathy’ (CSR).


Conditions associated

Age Related Macular Degeneration 

The central part of the retina (at the back of the eye) is called the macula and it has an important function as it controls the quality and sharpness of the central part of our vision.

Macular degeneration is a condition that affects the macula resulting in distortion or sometimes loss of central vision (not the peripheral vision) and this can cause problems, when it comes to everyday tasks such as reading and driving. Read More

Central Serous Retinopathy

Central serous retinopathy (CSR) is a condition that affects the retina- the light sensitive tissue that lines the back of the eye.

Central serous chorio-retinopathy (CSCR), refers to a collection of fluid under the retina. This is caused by a disturbance in the pumping action of special cells called RPE cells (retinal pigment epithelial cells) and/or abnormalities in the vascular (blood vessel) layer, known as choroid. RPE cell layer and blood vessel layer (choroid) line the outer surface of retina and both layers function to keep the retina healthy. This dysfunction results in fluid leakage under the retina in a bubble-like swelling called central serous chorio-retinopathy (CSCR).


Treatment 

The combination of laser light and light-sensitive dye helps to seal off the leaking area which then reduces leakage in the retina which will either stabilise the vision (stop it getting worse) or may even improve the vision. For patients with chronic (lasting more than 4 months) Central Serous Retinopathy (CSR) there are no other proven alternative treatments apart from PDT in cases where the disease does not settle by itself within the first few months. Without this treatment there would be a risk of the leak in the retina worsening causing further damage to the eyesight. For patients with wet macular degeneration this treatment is now reserved for patients who are unable to have the recommended first line treatment of injections of drugs into the eyeball (e.g. allergy to the drug or medical reason making it difficult for patients to attend for injection treatment) or cases where there is a specific type of wet macular degeneration where combination treatment is recommended (injections into the eyeball plus PDT treatment).

Retinal Detachment Surgery

About

Retinal detachment is a condition when the thin lining at the back of the eye (the retina) begins to come away and separate itself from the underlying wall of the eye which contains blood vessels that supply it with vital oxygen and nutrients.

If not treated promptly, retinal detachment will lead to blindness in the affected eye.

A retinal detachment is usually caused by a tear in the retina and this is termed a Rhegmatogenous retinal detachment. There are other types of retinal detachment namely Traction retinal detachment which is usually seen in advanced diabetic retinopathy and Exudative retinal detachment (usually seen in people with inflammation). It is the Rhegmatogenous retinal detachment which needs urgent surgery in most cases.


Causes 

The retina at the back of the eye sends signals to the brain, enabling us to see. Without a blood supply, the retina’s nerve cells die leading to loss of sight.

Retinal detachment is usually the result of the retina developing a tear in it. Once a tear develops and if not treated, fluid can go through the tear and cause the retina can pull away from the underlying blood vessel wall 

Very short-sighted people have the greatest risk of developing age-related retinal detachment (though the risk is still very small) because they are often born with a thinner than normal retina in the first place.

Previous eye surgery, such as cataract removal, may also make the retina more vulnerable to damage.

In some cases, a tear can develop if the eye is suddenly injured, such as by a blow to the face but this is less common.


Symptoms

Most people experience advance symptoms of a possible retinal detachment before losing their sight, including:

  • sudden appearance of floaters – black dots, specks or streaks that float across the field of vision (usually only one eye is affected)
  • web effect of lots of small floaters – some people see a single large black floater in the shape of a fly
  • sudden short flashes (no more than one second) of light in the affected eye
  • seeing a dark shadow like a curtain falling down from the outer aspect of the field of vision in the affected eye
  • blurring or distortion of vision

Without urgent treatment, the vision in the affected eye will start to deteriorate, creating the effect of a shadow or ‘black curtain’ spreading across the vision. If a person experiences a shadow in the vision then it is extremely important to consult an eye doctor immediately before the shadow spreads across the centre of the vision.

Retinal detachment usually only occurs in one eye, however if one eye is affected, there is a 1 in 10 chance that the retina in your other eye will also detach.


Treatment

Urgent Retinal Detachment treatment is essential to lower the risk of permanent vision loss. The Retinal Detachment treatment is mainly surgery and eye drops will not help.

Most but not all detached retinas can be successfully reattached through different types of surgery, followed by a few months of recovery when vision will be weak, affecting lifestyle activities such as driving.

Some people’s eyesight does not fully return after surgery and they have permanently reduced peripheral (side) or central vision. This can happen even if the retina is reattached successfully.

This risk is higher the longer the detachment was left untreated.


Diagnosis

If the eye specialist (ophthalmologist) suspects a retinal detachment, an examination of the back of the eye will confirm it.

Posterior Vitreous Detachment

About

Posterior Vitreous Detachment (PVD) is a common degenerative change, which affects one or both eyes in many people after middle age. It may present earlier in shortsighted patients or those who have sustained traumas to the eyes.

Thickening of the jelly casts shadows on the retina and are seen as floating shapes. These black “floaters “in your vision move with the eye and then settle as the eye rests. These are often described by patients as a “cobweb” or “insects”.

You may also be aware of flashing lights, like little flickers in the outer periphery. Usually these do not highlight a problem, however, it is important to have the eye thoroughly checked, as occasionally a retinal tear or a retinal detachment may occur.


Causes 

The vitreous gel in the eye is mostly made up of water. With age, small pockets can form inside the gel leading the tiny fibers that hold it to the retina to break and cause it to pull away from the retina and the optic nerve. As a result, a tear may occur in the retina or a hole in the nerve of the eye.

Majority of people get PVD at age 50 or older, and it is most common after the age of 80. 


Symptoms 

Thickening of the jelly casts shadows on the retina and are seen as floating shapes. These black “floaters” in your vision move with the eye and then settle as the eye rests. These are often described by patients as “cobwebs” or insects”.

You may also be aware of flashing lights, like little flickers in the outer periphery vision. Usually these do not highlight a problem, however, it is important to have the eye thoroughly checked, as occasionally a retinal tear or a retinal detachment may occur.


Treatment

There is no treatment required for posterior vitreous detachment. The floaters usually disappear after a few months, however, sometimes there will be a few residual floaters left behind. In time, you will start taking less notice of them and learn to ignore them.


Examination 

Your pupil will be dilated with drops. The doctors will view the edge of the retina to look for a retinal tear. The examinations may be carried out with several types of instruments. The Doctor may also apply a special contact lens and might exert an indentation on the outer part of the eye. 

Macular Hole Surgery

About

If you think of your eye as a camera, the retina is like the photographic film. It is a very thin layer of tissue, which is sensitive to the image focused on it, sending the information to the brain.

At the very centre of the retina is the macula. This is a very special area of the retina, which we use for reading and recognising complex shapes. Sometimes, a hole forms in the macula, which prevents it from working normally.  This affects your vision, particularly for reading and other visually demanding tasks, but it does not cause total blindness.


Causes 

  • Vitreous shrinkage and/or separation
  • Diabetic eye disease
  • High amounts of nearsightedness (myopia)
  • Macular pucker
  • detached retina
  • Eye injury

Symptoms 

Macular Holes usually start progressively. In the beginning stage of a macular hole, individuals may see a slight distortion or fogginess in their central vision. Straight lines or objects can start to look bowed or wavy. Reading and performing other routine tasks with the problematic eye becomes difficult to do.


Treatment

The only way to treat a macular hole is by having an operation. Eye drops or glasses are ineffective.

The surgeon will repair the macular hole by removing any pulling forces around it and place a gas bubble in the eye at the end of the surgery. You may need to be asked to position your head in a certain way for several days after the surgery.

The surgery is usually very successful in repairing and closing the hole. Visual recovery usually also happens and depends of how long the hole has been there. Macular hole repair should be done as soon as it is diagnosed after discussing it with your surgeon. 

Intravitreal Injection

About

The macula is the central part of the retina at the back of the eye. It is responsible for fine vision (reading, writing, watching television, and recognising faces). Patients with diabetes may develop macular oedema (swelling of the retina) due to leaking of fluid from blood vessels which can result in the vision becoming blurred.

Diabetic macular oedema

Diabetic eye disease is a leading cause of blindness. It is caused by changes to the tiny blood vessels of the retina (the light sensitive layer at the back of the eye). In diabetic macular oedema, blood vessels leak fluid into the retina.


Causes 

People who have had diabetes for a long time–about one in three – will develop diabetic macular oedema.

  • poorly controlled blood sugars
  • high blood pressure
  • high cholesterol levels
  • Smoking

Diagnosis

Diabetic macula oedema may be detected during annual eye screenings. Digital photographs of the retina may show signs of early diabetic macular oedema. At an early stage, symptoms or signs may not be noticed in the vision therefore, annual eye screenings are recommended to detect it early and being treatment.


Treatment

A course of three injections is recommended with each injection administered one month apart. The procedure is carried out in a clean environment using sterile technique. The eye is cleaned and local anaesthetic drops are given to numb the eye.

The eye may or may not be covered after the injection. If a pad is applied, this may be removed when you reach home.

Diabetic Retinopathy

About

Diabetic retinopathy is a complication of uncontrolled diabetes and consistantly high blood sugar over several years, resulting in retinal disease, which can interfere with its ability to transmit images to the brain through the optic nerve.

Blood vessels in the retina play an important role in supplying it with oxygen and nutrients, which keep it healthy and working effectively.

Diabetic Retinopathy can result in damage to the blood vessels; these may then bleed, leak or become blocked leading to cell damage in the retina itself.

There are varying forms and levels of severity of diabetic retinopathy – for example, when the retina becomes damaged, new blood vessels may grow on it and can burst, leading to bleeding and blurred vision. If the macula (the central area of the retina) is affected – this is called Diabetic Maculopathy – the disease has reached a much more advanced and serious stage.

High blood pressure combined with diabetes leads to an even more dangerous condition.


Types of Diabetic Retinopathy

  • Non Proliferative Diabetic Retinopathy
    Generally, this type of diabetic retinopathy does not affect vision because at the initial stage there are just a few enlarged blood vessels, with very minimal bleeding and leaking in the retina.
    An examination of the retina by an ophthalmologist will reveal some marks indicating the presence of the condition.
  • Proliferative Diabetic Retinopathy
    This condition can lead to seriously impaired vision as blood vessels grow in the retina and the threat is bleeding from these vessels which can lead to retinal damage, and even to retinal detachment at the back of the eye. Laser treatment is essential to avoid serious long term damage.
  • Diabetic Maculopathy
    Diabetic maculopathy occurs when blood vessels leak into the central area of the retina, which can cause swelling of the macula and affecting the quality of vision. Laser procedures, injections or surgery are the main treatment options.

Causes

Many diabetics, particularly those with poor control over diabetes that results in elevated blood sugar levels over long periods of time, have damaged blood vessels in the retina, the tissue lining the back of the eye that detects light and allows us to see. This results in a condition called diabetic retinopathy, which affects 8 out of 10 patients who have had diabetes for 10 years or longer.


Symptoms 

  • Spots or dark strings floating in your vision (floaters)
  • Blurred vision.
  • Fluctuating vision.
  • Impaired color vision.
  • Dark or empty areas in your vision.
  • Vision loss.

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 get regular eye screenings.