Procedures
What is blepharitis?
Blepharitis is an inflammation of the eyelids. Usually it causes symptoms such as red eyes and eyelid margins, grittiness, itchiness and discomfort. The eyes may feel dry, or may be crusty or stuck together in the morning. Other associated conditions may be recurrent eyelid cysts, conjunctivitis, and corneal ulcers.
What causes blepharitis?
Blepharitis may be caused by several conditions. The two most common are infection on the eyelid margin, and malfunctioning oil glands (see below). People with a skin condition called acne rosacea are prone to blepharitis.
The eyelids have a row of oil glands called the Meibomian glands (picture). These produce the oily component of tears, which is important in preventing tear evaporation and drying of the eye. Sometimes, the meibomian glands openings become blocked. The nature of the oil produced changes, becoming thicker. This causes inflammation of the eyelids, and also increased tear evaporation, resulting in dry eye. The oil can also be colonized with bacteria, which produce toxins that irritate the eye.
How do I treat blepharitis?
Once your doctor has made the diagnosis, a variety of measures may be prescribed. Unfortunately, blepharitis is usually not curable, but the condition can be significantly improved and its symptoms kept under control.
Antibiotic ointment or tablets may be prescribed to control any infection on the eyelids. Anti-inflammatory drops may help relieve the discomfort and redness.
The mainstay of treatment however is eyelid washing and hygiene.
How do I “wash” my eyelids?
Follow the routine below. Initially you may need to do it twice a day, but as the condition comes under control (which may take weeks) the frequency can be decreased.
Boil some water and place it in a clean glass. Add two drops of Johnson’s baby shampoo or a third of a teaspoon of sodium bicarbonate, and stir. Leave the mixture to cool until it is lukewarm.
Close your eyes and place a clean warm flannel over the eyelids for 5 minutes.
Wash your hands and then massage the eyelids in a circular motion for couple of minutes.
Place a clean cotton bud into the solution that you have prepared, and wipe the margin of the eyelids, along and just behind the eyelashes (it helps if you stand in front of a mirror and pull the eyelid away from the eye a little). Imagine you are removing mascara. Do this for both top and bottom eyelids. Use a fresh cotton bud for each wipe.
Commercial preparations
There are commercially available lid wipes which could be used straight from their packaging. These cut down on the time necessary to prepare a solution of dilated baby shampoo or bicarbonate of soda. They also allow lid hygiene to be done on the move away from home, or in the office.
In place of a hot flannel, you could also use a commercially available product called an EyeBag®. This is a small silk pillow filled with flax which can be microwaved to heat it up. It is a good heat source for melting hardened Meibomian gland secretions, and microwaving it sterilises it at the same time.
Ask at Tongdean Eye Clinic about these products.
What is a cataract?
A cataract is an opacity or cloudiness in the natural crystalline lens within the eye. Mostly this occurs with increasing age, but other factors such as smoking and exposure to sunlight can accelerate the formation of a cataract. Some diseases of the eye (such as inflammation and trauma) and general medical conditions (such as diabetes) and some medications can also cause cataracts to form.
Patients with cataracts typically complain of blurred vision, glare, and occasionally double vision. This can affect either distance vision (when driving or watching television for example) or near vision (as when reading a book), or both.
When should I have cataract surgery?
Cataract surgery has become a very safe and successful procedure, and there is no longer any need to wait until the vision is very bad or the cataract is “ripe”. Nowadays cataract surgery is performed when your vision has deteriorated to an extent where it is compromising your quality of life. You may be concerned about retaining your driving licence and wanting to keep yourself and other road users safe. Whether or not to have surgery is a very individual decision, and is generally made with advice from your optometrist (optician) and ophthalmic surgeon (ophthalmologist).
Surgery is the only viable treatment for symptomatic cataract. Laser treatment has proven to be technologically inferior to modern surgical techniques, although newer (femtosecond) lasers are being developed as an adjunct.
How do I arrange to have cataract surgery?
Cataract surgery is performed by a qualified ophthalmic surgeon. Your GP or optometrist (optician) can refer you.
At your appointment, your ophthalmic surgeon discusses the problems that you are having with your vision, and performs a detailed eye examination to determine the cause of the problem. This often involves dilating your pupil with drops (hence you may be advised not to drive to or from this appointment).
If a cataract is found to be the cause of the problem, the ophthalmic surgeon discusses whether surgery is advisable. If you decide to proceed with surgery, biometric measurements are taken to decide on the strength (optical power) of lens implant to place in your eye at the time of cataract removal. Instructions are then provided on preparation for surgery as well as details regarding dates and timings. You will be asked to sign a consent form, which states that you have understood the nature of the surgery, its intended benefits and possible complications.
What does cataract surgery involve?
Cataract surgery is performed in an operating theatre, more commonly as a day case, where the patient returns home the same day.
Before surgery, you will require eye drops which will dilate the pupil of the eye to be operated on. You may be asked to do this at home, shortly before leaving for the hospital.
On arrival at the hospital, your details are checked and the correct eye is then anaesthetised. Often this is as simple as instilling some anaesthetic drops. Sometimes it may involve an infusion of anaesthetic around the eye. Occasionally cataract surgery may be performed under general anaesthesia.
The eye is cleaned and covered with an ophthalmic sterile dressing. The surgeon performs the keyhole operation whilst looking through a microscope. The process of ‘phacoemulsification’ allows the removal of the cataract through a keyhole incision of 3mm or less, permitting rapid visual recovery.
A folding intraocular lens implant, or ‘IOL’, is inserted into the eye to replace the focusing power of your natural lens. No stitching is required in the majority of cases.
How much time do I need to recover?
You should notice an improvement in your sight the day after surgery. You should refrain from driving for a week or two following cataract surgery and you should prevent any fluid from entering your eye. It is important to avoid touching your eye, keeping your eye free from trauma for the first few weeks. Your surgeon will advise you as to when you should visit your optometrist (optician) for a sight test and possible glasses.
You will need to use antibiotic and anti-inflammatory eye drops for four weeks or so. These are designed to reduce the risk of infection and to calm inflammation.
What are the risks of cataract surgery?
Modern cataract surgery is very safe and successful, but as with all forms of surgery, there will be an element of risk. Sight-threatening complications such as bleeding, infection and retinal detachment are rare. Minor complications during surgery can result in the operation taking longer than the usual 20 minutes.
All cataracts are not the same and your ophthalmic surgeon will classify your procedure as routine or complex. Complex cases have additional risk factors, such as a small pupil, mature cataract, weak zonules, difficulty in accessing the eye (for example a deep set eye), difficulty in viewing the eye due to a corneal scar and weakness of the corneal endothelium, to name a few. A complex cataract procedure will require more planning and teamwork as well as a higher skill level. The risks remain, but are reduced by adequate preparation and planning.
Will I be able to get rid of my glasses?
Prior to surgery, biometric measurements of your eye (taken at Tongdean Eye Clinic using the latest most accurate IOLMaster laser), allow the choice of intraocular lens power, usually aiming for normal sight after surgery. Thus in the majority of cases, your distance vision will be quite good without glasses. However, you may still need fine-tuning glasses for long distance (when driving and watching television).
If there is significant astigmatism, it is possible to take additional measures to reduce this. Anti-astigmatic incisions could be made on your cornea at the time of surgery. Severe astigmatism can be partially or fully corrected by a toric IOL (toric intraocular lens).
Reading glasses will be required unless you chose to have good unaided near vision at the expense of unaided distance vision. Another possibility is to have your dominant eye corrected for unaided distance vision, and your non-dominant eye corrected for unaided near vision. This is known technically as ‘monovision’ which two thirds of the population could tolerate and find very satisfactory.
Yet another possibility is advanced IOL lenses which can give both good unaided distance and near vision. These are focusing and multi-focal implants. They do not work for all individuals and have some limitations including the possibility of glare and halos in low light.
You will need to discuss your options with your ophthalmic surgeon, who will advise you on the choice of implants.
What is a corneal graft?
A corneal graft is a cornea that has been removed from the eye of someone who has recently passed away. It is then transplanted onto the eye of someone who has a disease of the cornea, after their own cornea has been removed.
Why is a corneal graft performed?
There are many reasons to perform a corneal graft. All involve a disease of the cornea. The most common reason is a condition called keratoconus, where the cornea becomes conical instead of spherical in shape. Not all patients with keratoconus need a corneal graft, as many manage with spectacles or contact lenses. However, if a person with keratoconus cannot manage contact lenses, or has corneal scarring, a corneal graft may be required.
The second reason for a corneal graft is when the natural cornea becomes waterlogged and cloudy. A normal cornea is kept clear by pumping water out (a layer of cells on the back surface of the cornea, called the endothelium, acts as a water pump). The cornea becomes cloudy when it fails to pump water out. This used to be a common complication of cataract surgery but modern techniques have all but eliminated it.
Other common reasons for a corneal graft may be hereditary clouding of the cornea (called a dystrophy) or corneal scarring from infection or trauma. Occasionally, a corneal graft is performed to surgically remove infection from the cornea. On other occasions, thinning or perforation of the cornea (often also from infection) may require a corneal graft to restore the structure of the eye.
Are there different types of corneal grafts?
The procedure for a corneal graft differs depending on the disease.
The traditional corneal graft, called a penetrating or full-thickness graft, consists of replacing a 7 to 8mm disc of the patient’s cornea with a similar sized donor disc. The full thickness of the cornea is replaced and sutures are required to hold the donor cornea in place during healing.
If there is scarring limited to the superficial layers of the cornea, then these layers can be replaced selectively. This is called a lamellar corneal graft. Sutures are still required to keep the graft in place.
If the corneal disease involves a problem with pumping water, then the corneal pump or endothelium can be selectively replaced (called an endothelial transplant or endothelial keratoplasty). This can be done through a small incision, requiring only a few stitches.
Will my vision be better after a corneal graft?
This depends on the reason for the corneal graft. Most corneal grafts are performed in order to improve vision; however, glasses or a contact lens may still be required following the operation. This is because suturing the cornea can cause its shape to become distorted (called astigmatism). Sometimes removing overly tight sutures may improve vision.
It usually takes many weeks to months for the vision to improve after a corneal graft, with the final vision achieved after 18 to 24 months.
Sometimes co-existing disease in the eye (glaucoma or retinal disease for example) may limit the final visual outcome obtained. Your doctor will inform you of this if this possibility exists, prior to the operation.
What does the procedure involve?
Corneal grafting usually involves an overnight stay in hospital. The operation itself may take from an hour to a couple of hours.
The procedure is usually performed under general anaesthesia but occasionally a local anaesthetic may be used. The choice of anaesthesia should be discussed with your ophthalmologist and anaesthetist.
After the surgery the eye may be uncomfortable for a couple of days. The doctor will check your eye the morning after the operation, and instruct you on the after-care required. Drops consisting of an anti-inflammatory and an antibiotic are prescribed. Once you get home, you should wear a plastic shield at night to protect the eye. You should not drive, swim, lift anything heavy, rub your eye, or engage in contact sports. Generally you will be seen again within one to two weeks following discharge from the hospital.
You will need about a month off work following a corneal graft.
Drops are continued for many months after surgery. Exact instructions are given by your ophthalmic surgeon at each visit.
Are there any complications involved with a corneal graft?
Corneal grafting is a complex and major eye operation. Complications may occur at any stage, from the operation itself, to the early stages after the surgery, to many months later.
During the operation, the main risk is severe bleeding inside the eye. In severe cases this may cause loss of the eye or vision.
After the operation, the main risks are infection, rejection and failure of the graft. The signs of infection and rejection are redness, pain, and blurred vision. If you have any of these you should call your ophthalmic surgeon or Eye Hospital immediately.
Rejection occurs because your body recognizes that the corneal graft comes from another person and attacks it. The drops that you are prescribed suppress the eye’s immune response. You must continue to use them, as suddenly stopping the drops can in itself bring about rejection.
Grafts have a limited lifespan. This may be as little as a few months, and as long as decades. The lifespan of a graft depends on the quality of the initial graft material, the protection of the graft during surgical handling, the environment of the eye being grafted, and very conscientious aftercare.
If a graft fails, then repeat surgery may be required. However the success of grafting diminishes with every subsequent graft procedure.
Following a corneal graft, most patients will develop a cataract over time. Sometimes, if one exists at the time of grafting, it can be removed at the time of the operation. However, if a cataract develops subsequently, a further operation will become necessary. There is a chance that the corneal graft may fail after a cataract operation.
Glaucoma (high pressure damaging the optic nerve) is another frequent problem following graft surgery. Retinal detachment may also occur. Your doctor will monitor your eye for these complications. Hence having a corneal graft involves life-long follow-ups with an ophthalmic surgeon.
When will sutures be removed?
The earliest that sutures can be removed depends on the type of graft performed. For penetrating grafts this is generally not earlier than a year after surgery, and often around eighteen months. Patients should have been off any topical steroid for at least 3 months prior to suture removal. The length of time before sutures can be removed may be significantly shorter in lamellar grafts.
Because few sutures are used in endothelial grafts, this is becoming the procedure of choice for patients with endothelial disease.
What is diabetes?
Diabetes occurs when the body does not produce enough insulin (Type 1), or becomes insensitive to insulin that is present (Type 2). Insulin is a hormone produced by the pancreas that allows the body to more efficiently use glucose, a sugar. If there is not enough insulin, or it does not work, glucose levels in the blood become very high. This can cause a wide range of problems, including problems in the eye.
How does diabetes affect the eye?
Diabetes can have numerous effects on the eye. The two main problems are cataracts (see Cataract page) and retinal malfunction.
High glucose levels in the blood may damage the blood vessels in the retina. Damaged blood vessels may bleed, leak fluid, or cause parts of the retina to die from lack of adequate oxygen supply. In severe cases, new abnormal blood vessels may grow into the retina or the eye. These can cause bleeds into the eye, or pull on the retina causing retinal detachments, or block the channels that drain fluid from the eye, causing glaucoma.
Does anything make diabetic eye disease worse?
While diabetic eye disease worsens the longer you have diabetes, the following things can also make it worse:
Poor blood glucose control
High blood pressure
Pregnancy
Smoking
Kidney disease
Some medications, such as steroid tablets
Cataract surgery
How should I take care of my eyes?
The single most important thing that you can do is to control your blood sugar levels. Your general practitioner or physician will give you advice on how best to do this. Also, you should have your blood pressure checked regularly, and if it is high you will need tablets to control this. Stopping smoking is important.
Your general practitioner or physician will refer you for regular eye checks. Depending on the area in which you live this may be done in different ways. Sometimes it is done by photographs taken of the retina, sometimes by an optometrist, and sometimes by an ophthalmologist. Regular checks are recommended.
In general an eye check will involve a dilated pupil examination. Hence your vision will be blurred for the rest of the day, and you should not drive. It is advisable that someone accompanies you home from the appointment.
Can diabetic eye disease be treated?
Some levels of diabetic eye disease may just be monitored. Others may require laser treatment. Laser may be used to staunch leaking blood vessels in the retina, or to eliminate new abnormal blood vessel growth. Your ophthalmic surgeon will talk to you about this if it is required.
For all stages of diabetic eye disease, by far the most important treatment is prevention, by adequate blood sugar control.
What does laser treatment involve?
Most laser treatment is performed in a clinic, after the pupil has been dilated with drops. Anaesthetic drops are instilled into the eye, and a special contact lens put in place to prevent blinking and to allow the doctor to see and treat the retina. The laser treatment itself may cause a slight burning sensation or discomfort. Generally, each session lasts 10 to 20 minutes; several sessions may be required in severe cases.
Will my vision improve after laser treatment?
With pan-retinal photocoagulation (PRP) laser treatment, the vision is not expected to improve. The purpose of the laser treatment is to reduce the need for oxygen, thus encouraging abnormal new retinal blood vessels to regress.
With focal or grid laser treatment, the vision may improve over a number of weeks, as leaky blood vessels are sealed, and waterlogging of the macula subsides.
Are there any risks with laser treatment?
Rarely, the fovea may be inadvertently lasered, causing an acute diminution of vision. This can be avoided by the ophthalmic surgeon paying careful attention to detail, and the patient following the surgeon’s instructions.
Extensive laser treatment can reduce the amount of peripheral vision, which may have implications for driving. Your ophthalmic surgeon will discuss this with you, if this form of laser treatment should become necessary.
What is ‘dry eye”?
Dry eye refers to a variety of conditions where either insufficient tears or problems with their function, cause the sensation of dryness of the eyes.
Those suffering from dry eye feel that their eyes are uncomfortable, burning, itchy and painful. The eyes may also be red. The sight may also be blurred and unstable with each blink.
What causes dry eye?
As mentioned above, dry eye is not a single condition. This is because the ability of tears to keep the eye well lubricated depends on several factors:
Adequate tear production
The optimum composition of the tears, since tears are composed of:
An outer oil layer, which prevents evaporation
A middle water (aqueous) layer
An inner mucin (gel) layer, which helps the tears to spread
Blinking and lids: the lids help to keep tears on the eye, and blinking spreads tears over the surface of the eye
Hence a problem with any of these may cause dryness.
The most common conditions resulting in dry eye are keratoconjunctivitis sicca (KCS), and blepharitis. For information about blepharitis see Blepharitis.
Keratoconjunctivitis sicca (KCS) occurs when not enough of the water component of tears is produced. A gland behind the upper outer corner of the upper eyelid, called the lacrimal gland, produces tears. KCS may occur with age alone, and tends to be more common in women than men. Sometimes it is associated with a dry mouth (a condition called Sjogren’s syndrome). Occasionally KCS may accompany other general medical problems, like autoimmune conditions and arthritis, thyroid disease, and diabetes. Some medications may make dry eye worse.
How is dry eye diagnosed?
This diagnosis is generally made by an ophthalmologist, who performs a comprehensive examination of your eyes. Other tests, such as placing a strip of filter paper on the inner surface of your eyelid to measure tear production (called a Schirmer’s test) may also be performed. Blood tests may be requested to exclude any general medical conditions that may contribute to dry eye.
How is dry eye treated?
This is a complex area and is once again best managed by an ophthalmic surgeon. The various factors contributing to dryness (eg KCS, blepharitis and lid problems), need to be identified and treated.
KCS is treated by replacing tears, and by conserving the natural tears that are being produced. A large number of drops, gels and ointments are available for dry eye. In severe cases, the drainage tubes for tears may be plugged or closed up, in order to prevent tears escaping from the eye. Air-conditioned or over heated rooms and smoky or dusty environments are best avoided, and installing a humidifier at home may be beneficial.
What causes floaters?
Floaters are objects within the vitreous. The vitreous is the jelly that fills the space between the lens and the retina.
Objects that float within the vitreous cast shadows on the retina, which are then seen as dark floating shapes. They are more prominent when looking at a uniform and pale background, such as a white screen or blue sky.
In youth the vitreous is attached to various sites on the retina. The most common form of floaters occurs following a posterior vitreous detachment. Here the vitreous peels away from its attachments to the retina and creates a ‘cobweb’ vision effect. Changes in the vitreous itself may cause floaters to appear. This is a normal age-related change, but it may occur earlier and be more pronounced in short-sighted (myopic) individuals.
Sometimes, as the vitreous pulls away from the retina, it may tear the retina, and cause bleeding. Blood within the jelly of the eye may cause more floaters. Occasionally, the bleeding may be severe enough to cloud the vision.
Healthy young adults also often have floaters. These may be associated with changes in the vitreous, or may be persistent remnants of blood vessels that were present in the eye whilst it was developing, but later disappeared.
Numerous other conditions may cause floaters, such as bleeding in the vitreous from other causes (diabetes, blood vessel blockages), or inflammation, or infection.
What causes flashing lights?
Flashing lights occur when the vitreous pulls on the retina, and causes traction. Traction on the nerves of the retina causes them to fire, and this appears as a flash. Flashes associated with floaters are more likely to mean that a retinal tear has occurred.
What should I do if I have floaters?
If they have been present for a long time, then a serious problem is unlikely. However, you should still make an appointment with an ophthalmic surgeon to check your retina.
If the floaters are of sudden onset, especially if associated with flashes, then you should ask your optician/optometrist or general practitioner for an urgent referral to an ophthalmologist or to the A&E department of your local eye hospital.
What will happen when I see the ophthalmologist?
Your eyes will be dilated with drops (hence you should not drive yourself to the appointment, as your vision will be blurred for the remainder of the day). The ophthalmologist will examine your retina to exclude any tears or detachment of the retina.
If there is a tear in the retina, it can be lasered, depending on its size, location and whether fluid has accumulated under the retina. Laser acts as a spot-welder, to secure the retina onto the back of the eye.
If there is a detachment of the retina, an operation will be necessary. A retinal detachment occurs when fluid from the vitreous enters a hole or tear in the retina and the retina then peels away. This situation requires surgery; usually performed by an ophthalmologist who specializes in retinal surgery.
If there are no tears or detachments in the retina, you will be reassured that nothing serious is present. The floaters may be present for many months before disappearing. However, if you notice new floaters, especially if they are numerous or associated with flashes, you must seek urgent advice from your ophthalmic surgeon.
Can floaters be treated?
Yes, but not without risk. Where floaters are truly bothersome, they can be removed by vitrectomy (removal of the vitreous jelly). This is a major operation for your eye, and carries risk of retinal injury, infection and late cataract formation.
Where there are just one or two discrete large floaters, it may be possible to disperse them with YAG laser treatment. This is done with a specialist contact lens, and may require multiple sessions to break them up.
What is glaucoma?
Glaucoma comprises a group of eye conditions all leading to loss of peripheral vision, as a result of damage to the optic nerve (the nerve that carries images from the eye to the brain).
Early glaucoma may only be detected at a visit to an optometrist or ophthalmic surgeon, as, in the initial stages, there are no symptoms. Later patients may be aware of a missing area in their field of vision. As this progresses, tunnel vision may result.
Sometimes patients may experience eye pain, headaches or halos appearing around lights. This is due to the elevated pressure in the eye.
Who is at risk of Glaucoma?
The most common form of glaucoma is called Primary Open Angle Glaucoma (or Chronic Open Angle Glaucoma). The main risk factor is high eye pressure, although glaucoma may still occur at normal eye pressures. It tends to be more common as one ages, and in those who have a family history of glaucoma. Certain racial groups, especially people of African descent, tend to have a higher occurrence. Other factors include a propensity to migraine, diabetes, and over-treatment of raised blood pressure.
The other main form of glaucoma is Acute Closed Angle Glaucoma. Here the front structures of the eye (the lens and iris) are crowded into a smaller space, resulting in restricted drainage of fluid from the eye. The build-up of fluid inside the eye causes very high pressure. This form of glaucoma is mainly seen in older, longsighted people, and in the Oriental race.
Should I get checked?
In general, young people under the age of 40 are at low risk for glaucoma, and do not require routine screening. However, if you have a family history of glaucoma, a glaucoma check by an optometrist or ophthalmic surgeon is probably a sensible precaution.
Over the age of 40 years, most people should have their eyes checked at least every two years. Eye pressure measurement is a routine part of any eye check. In the event of a family history of glaucoma, more frequent examinations may be advisable.
Eye pressure may be checked by many different methods. The two main ways are firstly an air-puff technique, commonly used by optometrists (opticians) and secondly an applanation device. In the latter, more accurate technique, a drop of anaesthetic is instilled into the eye, and a device makes light contact with the eye to determine its pressure.
The other main test performed as part of a glaucoma check is a visual field test. The patient sits in front of an illuminated screen, and a spot of light appears at various points on the screen. The patient presses a button when the spot is seen, and the computer records this. Eventually, a map of the patient’s field of vision is created by the computer. The test takes approximately 5 to 10 minutes per eye.
Further tests include measurement of central corneal thickness (CCT), gonioscopy, and 24-hour monitoring of eye pressure:
Central corneal thickness is measured with a pachymeter. The relevance lies with the effect of corneal thickness on its stiffness, thus affecting the accuracy of eye pressure measurement. Knowledge of CCT allows an adjustment to be made.
Gonioscopy is done with a mirrored contact lens being placed on the eye which has been anaesthetised with eye drops. The internal angle of the anterior chamber of the eye can be viewed to determine if it is open or closed (blocked) to varying degrees. This information allows the correct treatment to be planned. 24-hour eye pressure monitoring may be necessary for a number of reasons. This is a necessary test prior to making a diagnosis of normal (low) tension glaucoma. It is also recommended when there is unexplained worsening of visual field loss.
Occasionally, dilating drops may be instilled into the eye in order to better examine the retina. If this is done, it is advisable not to drive home from the appointment.
How is glaucoma treated?
Glaucoma treatment is generally initiated by an eye specialist (ophthalmic surgeon). At your first visit, the ophthalmic surgeon may repeat eye examinations and tests previously carried out by the optometrist/optician in order to determine whether treatment is necessary.
Treatment in the first instance usually involves eye drops. Many different drops are available; all work by lowering the eye pressure. Your eye specialist will discuss which drop is best suited to you. You will be seen again after an interval of some weeks to ensure the drops are working and that you are without side effects. Anti-glaucoma eye drops control your eye pressure and need to be continued for life; they do not cure the condition. Life-long follow-up is required and the eye drops are modified as necessary.
Modern anti-glaucoma eye drops are highly effective, but a small number of patients require laser (laser trabeculoplasty) or surgical treatment (trabulectomy). Laser treatment can replace or enhance treatment with eye drops. It is an outpatient procedure and can be repeated as necessary every 18 months or so. Surgical treatment involves creating an additional drainage channel; whilst it has a good chance of long-term pressure control, it does carry risks of bleeding, infection and future cataract formation.
Will I go blind from glaucoma?
Modern medical, laser and surgical treatments for glaucoma will result in minimising progression of damage to your sight. It is therefore of utmost importance that you adhere to using eye drops as directed by your ophthalmic surgeon and that you attend regular life-long follow-up appointments.
Visual field loss, unless severe, goes unnoticed by the patient. It is therefore important to have formal visual field testing – which is also a requirement for the DVLA. If you suffer from glaucoma, it is your responsibility to inform your insurer and the DVLA of your condition otherwise your driving licence and insurance policy may not be valid.
Please see DVLA requirements.
What is Laser Refractive Surgery?
Laser refractive surgery (keratorefractive surgery, or laser vision correction) describes a range of procedures on the cornea, aimed at eliminating or reducing the need to wear spectacles or contact lenses.
A clear image, without glasses, results from the eye focusing light on the retina.
Short-sighted (myopic) people have optics that are too powerful, focusing light in front of the retina. By flattening the cornea, its optical power is reduced, allowing light to fall focussed on the retina.
Long-sighted (hyperopic) people have optics that are too weak, focusing light behind the retina. By steepening the cornea, its optical power is increased, and light is brought onto the retina.
Astigmatism occurs when the focusing power of the eye is different in various meridians. Instead of being spherical, the eye is shaped more like a rugby ball, so that its curvature is different in different directions. This results in light being brought to focus at several different points, which may give the sensation of a halo, or of multiple images. By reshaping the cornea to make it spherical, one can reduce or eliminate astigmatism.
Reshaping of the cornea is performed with the aid of a specialist laser, called an Excimer Laser.
What are the different types of corneal refractive surgery?
The main procedures performed are called:
LASIK (Laser Assisted In-Situ Keratomileusis)
PRK (PhotoRefractive Keratectomy)
LASEK (Laser Assisted Epithelial Keratomileusis)
All three procedures involve reshaping the eye with an excimer laser.
With LASIK, a flap of the cornea is made, either with a blade (called a microkeratome) or a different laser (a femtosecond laser). This flap is about 100 microns in thickness. The flap is lifted, the excimer laser applied to reshape the cornea, and the flap repositioned.
With PRK, no flap is made. The superficial cells of the cornea (called the epithelium) is removed and the excimer laser applied. The cornea is left bare to heal, often under cover of a contact lens.
In LASEK, the surface layer, or epithelium, is peeled back as a very thin flap. The excimer laser is applied. After reshaping the cornea, the epithelium is replaced back as a flap. A bandage contact lens is applied to keep the epithelium in place.
Why use different procedures?
PRK was the first laser corneal refractive procedure devised. It is still widely performed, and is very safe. However it has two main drawbacks. Firstly, there can be significant discomfort after the procedure, which may persist for up to a week. Secondly, the cornea occasionally responds by scarring, and causes haze. This may result in blurred vision and glare. In practice, the discomfort usually only lasts 24 hours or so, and the visual results are excellent provided the amount of correction is within recommended limits. PRK is particularly suited to those engaged in contact sports and those with naturally thinner corneae.
To increase comfort and to allow higher degrees of correction and more rapid visual recovery, LASIK was developed. It tends to have less haze, and is much more comfortable after the operation. Patients may even return to work a few days after surgery. However, in making a flap, new problems may be introduced. Sometimes these are surgical, where difficulties in creating the flap may suspend surgery. Other problems can occur after surgery, when the flap may move, or be subject to trauma. It is also possible for superficial (epithelial) cells to grow under the flap, or inflammation to take place under the flap. Hence for certain eyes, and for people in certain occupations, LASIK may not be desirable.
To combine the safety of PRK with the comfort of LASIK, LASEK was devised. Replacing the epithelium reduces the amount of post procedural pain. However it is still more uncomfortable than LASIK. Critics also argue that the epithelium does not survive and may become an infection risk.
Am I suitable for laser refractive surgery?
This is something to discuss with your ophthalmic surgeon. In general, you need to have a healthy cornea, with a stable prescription from your optician. For this reason, people under the age of 21, or pregnant women are not generally considered. Also, if your prescription has been changing significantly, it may be wise to delay surgery.
People who have had corneal problems in the past, such as infections, may not be suitable. Abnormalities of the shape of the cornea, especially a condition known as keratoconus, mean that laser refractive surgery is usually not possible. Also, if you have a general medical condition which may affect wound healing, such as diabetes or an autoimmune disease, laser refractive surgery may not be for you.
Are there risks of laser refractive surgery?
Like all surgery, refractive surgery does have risks. These are detailed more comprehensively under the descriptions of individual procedures.
Will I be able to get rid of my glasses or contact lenses?
This depends on your prescription. For low to medium prescriptions, there is a good chance that you will be spectacle free. For very high prescriptions, it may only be possible to reduce the thickness of your glasses or strength of your contact lenses.
For reading vision, most people will eventually (usually mid 40s) require reading glasses. Some people with medium short-sight may be able to read without glasses. This may even be useful for certain occupations or hobbies. After refractive surgery, glasses will not be required for distance vision, but reading glasses may be required depending on your age.
Some people choose to have one eye only made clear for distance. They may then be able to read with one eye, and drive with the other (monovision). However, the trade-off is some loss of depth perception. Some people may even feel a little unbalanced. If you are considering a monovision outcome, it may be wise to have a trial with a contact lens to simulate this first. Your ophthalmic surgeon will discuss this in further detail with you.
What will happen at my first visit?
The main purpose of your first visit will be to determine whether your eyes are suitable for laser refractive surgery. Hence, your prescription will be checked, scans of you corneae taken, and your eyes examined. This may involve dilating your pupils so it would be wise for someone to accompany you, who is able to drive you home. Your visual requirements will be discussed in detail. Your ophthalmic surgeon will then discuss treatment options with you.
If you wear contact lenses, it is necessary to discontinue these for two weeks prior to this first appointment.
LASIK (LASER ASSISTED in SITU KERATOMILEUSIS)
What is LASIK?
LASIK is a form of corneal refractive surgery. The cornea is the front clear surface of the eye. By reshaping the cornea, the need for spectacles or contact lenses to correct distance vision, for people who are naturally long or short sighted, may be reduced or eliminated.
How does it work?
A thin flap of the cornea is created with a motorized blade (microkeratome) or a laser (femtosecond laser). This flap is peeled away, and the underlying cornea is reshaped using an Excimer laser. The initial thin flap is replaced, allowing the cornea to heal faster, and reducing discomfort.
Does LASIK work?
Yes. The majority of people who have LASIK surgery do not require glasses for distance vision afterwards. Those who still require glasses, will have a reduced prescription. However, most people will eventually require reading glasses, usually in their forties.
Is everyone suitable for LASIK?
No. People with very high short or long-sightedness may not qualify for LASIK. Also, people who have certain medical conditions or eye conditions may also not be suitable (see section on Laser Refractive Surgery). Because of the risk of flap trauma, if your occupation involves the risk of injury to the eye, you should discuss your options with your ophthalmic surgeon.
Prior to undergoing LASIK, you will have a comprehensive eye check by your ophthalmic surgeon. This may involve a number of different tests, including one or more tests of your glasses prescription, and imaging of your corneae. You will be advised whether or not you are suitable for LASIK. If you do wear contact lenses, it is preferable to leave these out for 2 weeks prior to this initial appointment.
Are there any risks attached to LASIK?
All eye surgery carries the risk of serious complications resulting in loss of vision. Thankfully in LASIK surgery these complications are rare. During the operation, the most common complication occurs in cutting the flap (an incomplete flap, a buttonholed flap etc). Flap problems may mean that the operation has to be cancelled and rescheduled some months later. Following the operation, problems including infection, scarring, warpage of the cornea, and retinal detachment may occur.
The most common complaint after LASIK is that of night-time glare and haloes (haloes refers to seeing a glowing circle around a point light source such as street lights and car headlamps) which may cause a problem when driving at night. The percentage of people who experience this can be as high as 5%. However it does improve with time.
Your ophthalmic surgeon will explain in full the risks involved with LASIK surgery, and provide you with additional printed material to read prior to the operation. You will be required to sign a consent form to say that you understand the risks involved.
Do I need to stay in hospital for LASIK?
No, LASIK surgery is performed in day centres. You come in for the operation, which is usually performed with anaesthetic drops alone, and go home soon afterwards.
There is usually not much pain after LASIK surgery. In general the eyes may be a little red, scratchy or uncomfortable. Paracetamol or a mild anti-inflammatory is usually sufficient for pain relief
You may have a contact lens placed on the eye after surgery and there will be drops to use. You will be checked the following day and given advice on drop use and any further appointments.
How soon will my vision be improved?
Generally, your vision will improve within 2 days.
How long should I remain off work?
It depends on your work. For office workers 1-2 days off is usually sufficient. If you work outdoors or in a dusty environment, or if your work involves heavy lifting, it is generally advisable to have a week off work.
Are there alternatives to LASIK?
Yes. LASEK and PRK are similar laser corneal refractive treatments. In LASEK a very thin corneal flap is made, much thinner than for LASIK. Because a blade is not used (usually the flap is made with an alcohol solution), the risk of flap damage is eliminated. Because the flap is replaced on the eye after the procedure, the eye is less irritable than following PRK (but not quite as comfortable as following LASIK).
With PRK, there is no need for a corneal flap. Instead, the surface layer (epithelium) is removed and the laser applied. In general the visual results of PRK are as good as LASIK, but the recovery time is longer and there may be slightly more discomfort. However, PRK can be used for some cases that are not suitable for LASIK.
For some patients, in particular those with cataracts, lens-based procedures may be more suitable than corneal laser surgery.
It is important to discuss all your options with your ophthalmic surgeo
What is macular degeneration?
The macula is the centre of the retina. It is responsible for fine vision, such as when reading, for colour vision, and for recognising faces.
With macular degeneration, the retina of the macula slowly perishes. There is a wide variation in the degree to which this occurs, and speed of progression. Mild forms are seen in most elderly people. However, when pronounced, it may result in loss of central vision.
What are the different types of macular degeneration?
The two main types of macular degeneration are called ‘dry’ (or non-neovascular) and ‘wet’ (or neovascular). 90% of affected people have the dry form, only 10% have the wet form.
Dry macular degeneration is characterized by the following abnormalities seen at the macula:
Drusen: glistening yellow spots seen under the retina
Changes in the pigment epithelium (the pigmented layer under the retina)
Geographic atrophy: death and thinning of the retina itself
Dry macular degeneration generally results in slow loss of central vision.
With wet macular degeneration, blood vessels grow underneath the retina. These may leak fluid or bleed, resulting in a more rapid loss of vision.
Why does it occur?
The short answer to this is that no one knows. There are many contributory factors. The main problem seems to lie beneath the retina itself, with accelerated ageing of some structures called the retinal pigment epithelium, Bruch’s membrane and the choriocapillaris (the blood supply to the inner retina).
The condition is certainly more prevalent as people age. There is a hereditary component; some may manifest the changes in their early adult years. Smoking and diet play a role. Many infections have been proposed as causes, but none is proven.
Will I go blind from macular degeneration?
No. At its worst, the central vision will be lost. This may affect your ability to recognize faces easily, to read, and to drive. However, the peripheral vision remains intact, and so walking around and navigating usually remains unaffected.
Many people have milder forms. This may mean that their central vision is blurred, or distorted, but that they are still able to read and recognise faces.
How is it diagnosed?
Examination by a qualified ophthalmologist is required. This generally involves a dilated pupil examination, and hence it is worth bringing a companion to the appointment who will drive or accompany you home. (You should not drive after your pupils have been dilated, as your vision may be blurred for the remainder of the day).
Sometimes, additional tests are necessary. This may involve an OCT scan and a fluorescein angiogram (FFA). With an OCT, the back of the eye is scanned with an invisible laser beam to determine the thickness, structure and waterlogging of the retina, and its relation to the posterior vitreous and underlying Bruch’s membrane. It is a non-invasive test but your pupils will need to be dilated. With an FFA, fluorescein dye injected into a vein travels to the blood vessels of the eye, where its passage is recorded photographically. The dye may highlight abnormal blood vessels or changes in the retina.
Is there any treatment?
The treatment available depends on the type and extent of the condition.
Many treatments are available for wet macular degeneration. The abnormal vessels may be lasered. A special dye may be used to specifically target the vessels and laser them (photodynamic therapy). These have more or less been superceded by anti-VEGF compounds, which suppress the growth of new vessels, injected directly into the eye. Not everyone is suitable for these treatments; the decision is normally made following clinical examination, an OCT and a fluorescein angiogram, performed by your ophthalmic surgeon.
No treatment exists for the advanced forms of dry macular degeneration. For patients with moderate macular degeneration, especially where one eye has already been affected by the advanced stages, high dose multivitamins may help prevent progression. Many formulations are available, and you should discuss which is most appropriate for you with your ophthalmic surgeon.
What can I do if I have macular degeneration?
Arrange to speak to your ophthalmic surgeon. They will advise you on whether any treatment is available.
You can monitor progression by keeping an Amsler grid at home, and looking at it regularly. You need to wear your reading glasses, and close each eye in turn. Looking at the centre spot, you should note any patches of blurring or distortion. Any new or larger areas should be reported promptly to your ophthalmic surgeon or the A&E department of your local eye hospital.
In general, a healthy diet comprising dark green, leafy vegetables and carrots is recommended. Giving up smoking is important. Minimizing saturated fats, and ensuring a regular intake of fish is thought to be of some benefit. Sunglasses and hats should be worn when outdoors to reduce ocular exposure to harmful ultraviolet rays.
Many support networks exist for sufferers of macular degeneration. Most ophthalmic surgeons will be able to place you in contact with support groups. Low vision centres may help by providing aids such as magnifiers, and replacing visual tasks with aural ones (for example audio books, talking watches, and talking kettles), and by making modifications to your house (such as installing bath rails).
A number of common lid conditions are described below.
Chalazion
A chalazion (also known as a Meibomian cyst), is a lump in the eyelid, caused by a blocked Meibomian gland (an oil gland in the eyelid). These are very common, and often respond to heat and massage. Chalazia or Meibomian cysts which get infected swell up and become tender, necessitating treatment with antibiotics, usually by mouth. A persistent cyst would need to be drained by incision and curettage, a relatively simple procedure performed under a local anaesthetic.
Ectropion
An ectropion is the term applied to an everted eyelid (the eyelid margin rotates away from the eye), causing watering, redness and irritation of the eye. There are different types; the most common is caused by looseness of the eyelid tissues. An operation can be used to tighten the lid and bring it back into position.
Entropion
Here the eyelid margin rotates in toward the eye, so that lashes rub against the eyeball. It can cause significant irritation and pain, and can even result in ulcers on the eye. An operation is required to tighten the eyelid and rotate the lashes away from the eyeball.
Operations for the above lid malpositions may need to be repeated.
Watering eyes
There are many causes for watering eyes. The most common is a blockage of the drainage tear ducts which can be diagnosed in the consulting room by syringing the tear ducts with saline. If the tear ducts are open, saline would flow freely to the back of the throat. If this does not happen, there is a blockage of the tear ducts. However, these ducts are very long, and run from the corner of the eye, via a convoluted pathway, into the nose. Thus the treatment may be simple or complex, depending on where exactly the blockage is located.
What is PRK?
PRK is a form of corneal refractive surgery (the cornea is the front clear surface of the eye). By reshaping the cornea the need for spectacles or contact lenses to correct distance vision may be reduced or eliminated, for those who are naturally long or short sighted.
How does it work?
The cornea is reshaped using a laser. For short-sighted people, in whom the cornea is too steep, the reshaping makes the cornea flatter. In long-sighted people, in whom the cornea is too flat, the cornea is made steeper.
Is PRK successful?
Yes. The majority of people who have PRK surgery do not require glasses for distance vision afterwards. Those who still require glasses will have a reduced prescription. However, almost everyone will require reading glasses sooner or later, usually when they reach their forties.
Is everyone suitable for PRK?
No. People with very high short or long-sightedness may not qualify for PRK. Also, people who have certain medical conditions or eye conditions may also not be suitable. Prior to having PRK, you will have a comprehensive eye check by your ophthalmic surgeon. This may involve a number of different tests, including one or more tests of your glasses prescription, and imaging of your cornea. You will be advised whether or not you are suitable for PRK. If you do wear contact lenses, it is preferable to leave these out for 2 weeks prior to this initial appointment.
Are there any risks attached to PRK?
All eye surgery carries the risk of serious complications resulting in loss of vision. Thankfully in PRK surgery these complications are rare. However they include infection, scarring (haze), warpage of the cornea, and retinal detachment.
More commonly, patients may complain of night-time glare and haloes. This may cause a problem with driving at night. The percentage of people who experience this can be as high as 5%. However it does improve with time.
Your ophthalmic surgeon will explain the risks involved with PRK surgery fully, and provide you with additional printed material to read prior to the operation. You will be required to sign a consent form to say that you understand the risks involved.
Do I need to stay in hospital for PRK?
No, PRK surgery is performed in day centres. You come in for the operation, which is usually performed with anaesthetic drops alone, and go home soon afterwards.
The eyes may be a little red, scratchy or uncomfortable, and they may be sensitive to light. Remaining in a darkened room and applying frequent ice packs, makes the eyes feel more comfortable. If you need to go out, wearing UV protective sunglasses is a good idea. Paracetamol or a mild anti-inflammatory is usually sufficient for pain relief.
A contact lens is often placed on the eye at the final stage of the procedure. This will generally be removed four to five days after surgery. There will be drops to use and you will be checked on the day following surgery and given advice on drop use and any further appointments.
How soon will my vision be improved?
Generally, your vision will take a few weeks to sharpen altogether.
How long should I remain off work?
It depends on your work. However, in general a week off work is sufficient.
Are there alternatives to PRK?
Yes. LASIK and LASEK are other types of corneal refractive surgery (see the LASIK and Laser Refractive Surgery information pages). While the recovery time for LASIK is often shorter than for PRK, it may not be suitable for everyone. Your ophthalmic surgeon will be able to advise on choice of procedure.
