This section of the website contains information for patients about the most common ophthalmic conditions treated at the Premier Eye Clinic.
Cataract l Glaucoma l Dry Eye Syndrome l Meibomian Cysts l Pterygium l Pinguecula l Surgery for short sightedness and long sightedness with Lens Implants
If you require information or need consultation regarding an eye problem please contact the Premier Eye Clinic for further assistance
Unlike most of the tissues in the body the human lens is not worn away and replaced. It constantly grows throughout life. The best way to consider the human lens is like an onion in which, with increasing age, further layers [onion skins] are added. The centre of the lens is, therefore, as old as the patient, having been laid down early on in development. During the patient’s forties and fifties this thickened lens becomes less elastic giving rise to presbyopia (Latin = old age vision). This increased stiffness of the lens causes a loss of accommodation, or focusing power, requiring the use of increasing strength reading glasses. As the patient continues to get older the lens becomes slightly discoloured or opaque and these age changes within the lens are known as cataract.
Cataract surgery, today, is carried out with the use of ultrasound energy “phakoemulsification”. In this procedure a very small hole is made into the eye (3mm or less) and an ultrasonic phakoemulsification probe is inserted to soften the lens and wash it out.
Although Lasers have been used to “break up the cataract” phakoemulsification has remained the Gold Standard for safe small incision cataract surgery. Once the central hard part of the cataract “the nucleus” has been removed by phakoemulsification the soft outer portion of the cataract “the cortex” is vacuumed out. An ‘injectable intraocular lens’ is then placed in the remaining “outer transparent lens capsule” which shrink wraps round the soft lens holding it in position.
Because the lens is being replaced the eye can be made to have normal vision “emmetropia” or be left slightly short sighted “myopia” or slightly long sighted “hyperopia”; in this way a patient who has worn glasses all their life can be made to have any desired refraction.
Any amount of short sighted or long sighted, therefore, can be treated with an ‘intraocular lens’ but until quite recently it was not possible to treat moderate or large amounts of astigmatism with an intraocular lens. (Astigmatism occurs when there is an inequality of the power of the cornea in different directions, due to different curvature. This means that the cornea has the shape of the side of a Rugby Ball while a person who is just short sighted or long sighted, without astigmatism, has a cornea the shape of a Soccer Ball). It is now possible to treat astigmatism at the time of cataract surgery by using a ‘Toric Intraocular Lens’ which can be injected in the same way as a standard Intraocular Lens.
Most eye surgeons correct their patients for normal vision in both eyes for distance (emmetropia); this has the disadvantage of leaving them so that they are unable to read at all without the use of reading glasses. In the Peckar Eye Clinic the majority of patients are corrected for monovision; this corrects one eye for distance and the second eye is corrected for intermediate (-1.2 to -1.6 dioptres).
This allows the patient to be able to read the prices in shops, see the instruments on their car and in most cases read their bills, see their watch and do some reading as well as viewing their computer. This leaves them spectacle independent for most of the time although some will require glasses for reading or driving when this is prolonged. Mr Peckar has used this technique for the last twenty-four years successfully, many patients reporting that they do not require glasses at all.
Multifocal Intraocular Lenses
An alternative to the use of monovision has been the use of ‘Multifocal Intraocular Lenses’. These lenses allow patients to see for near and distance in one eye. However, unlike multifocal contact lenses or glasses they work by producing multiple images on the retina which the brain has to “sort out”. This causes some loss of definition or of “contrast sensitivity”. The results of multifocal lenses, therefore, have no great advantage over monovision. In monovision the patient can always be corrected fully with the use of spectacles but with multifocal intraocular lenses there are some patients who are unable to tolerate the multifocal intraocular lenses, and may request their removal an “Intraocular Lens Exchange”.
Accommodative Intraocular Lenses
In order for some patients to see both near and distance in each eye the ideal would be to have an accommodative intraocular lens. There are no true accommodative lenses available, at present, all the accommodative intraocular lenses are “pseudo-accommodative”. They have not been shown to have any long term benefits over monovision.
Timing of cataract surgery
With the widespread use of intraocular lenses it is possible to operate on a cataract at any time during its development; there is no need for the cataract to be “advanced or ripe”. As soon as a patient develops symptoms of reduced vision, or glare associated with their cataract, they should consider cataract surgery.
Early cataract surgery
For many patients in their fifties and sixties, who have lost their accommodation, early cataract surgery may offer a number of advantages over other forms of surgical intervention, even if they have only minimal symptoms. In the presence of early cataract the refractive benefits of ‘early cataract surgery’ over ‘Phakic Intraocular Lenses’ or ‘Excimer Laser Treatment’ need to be considered.
Modern cataract phakoemulsification is 98% successful. Cataract surgery is carried out as a Day Case procedure and can be carried out using an injection around the eye to freeze the eye (Local Anaesthetic), using a short acting General Anaesthetic or occasionally using drops alone (Topical Anaesthesia). The majority of patients go home on the day of surgery however some patients, particularly if they are elderly or live alone, may request an overnight stay; more information can be obtained at the clinic.
Because the artificial intraocular lens is shrink wrapped in the natural remnants of the patient’s original lens (lens capsule) the patient will develop symptoms if this capsule thickens up “as part of the healing process”. This can occur up to four years after cataract surgery when the patient has symptoms of slight fuzziness in their vision like a “greasy thumb print on the back of their spectacles” or “like a very early cataract forming”. Posterior capsular thickening or opacification (PCO) is easily treated, however, as an outpatient procedure, using a YAG Laser. The procedure takes about five minutes to perform but the patients’ should expect a total visit time of around two hours.
Patients with large degrees of short sightedness or long sightedness may be suitable for intraocular lens surgery using either: -
i) Phakic intraocular lenses (PIOLs).
These are used in patients who still have their accommodation and are added to the eye in addition to the patient’s natural lens while “intraocular lenses” are used with removal of the patient’s natural lens (see early cataract surgery and cataract surgery). The choice of the type of lens to be inserted would depend on the patient’s individual circumstances, refraction and age. Examples of these are the “Intraocular Contact Lens” and the “Iris Clip Lens” (this is like a contact lens inside the eye which is clipped to the iris” ( see video section).These are intraocular lenses that are placed into the eye in addition to the patient’s own natural lens. They are most commonly used to correct short sightedness (myopia) but can also be used for long sightedness (hyperopia) and astigmatism.
ii) Intraocular lenses (IOLs): used to replace the patient’s own natural lens or cataract. See Cataract Section above
Glaucoma occurs in 1–2% of white people aged over 40 years, increasing to 5% at 70 years. In black people glaucoma is more severe and presents at a younger age with higher intraocular pressures; it is more difficult to treat, and is the main irreversible cause of blindness in black populations of African origin
Glaucoma is a major cause of blindness in the UK being responsible for 8% of new blind registrations.
Chronic open angle glaucoma produces no symptoms, until extremely advanced, and prior to the advent of screening patients often only presented when they had already lost most of their vision, in one eye. Fortunately with the widespread use of screening, for glaucoma, the condition is often picked up early. It cannot be completely “cured” but the aim of treatment is to slow down the progression so that in a patient who might lose significant vision e.g. ‘over a five year period’ with treatment this might take ‘twenty five years’.
Open angle glaucoma is usually treated with the use of ‘glaucoma eye drops’ in order to reduce the pressure. There are four types of eye drops
- Prostaglandin analogues: these have the advantage that they only have to be used in the eye once a day
- Carbonic Anhydrase Inhibitors: these usually require twice daily (twelve hourly treatment)
- Beta Blockers: these usually require twice daily (twelve hourly treatment)
- Alpha agonists: these usually require twice daily (twelve hourly treatment)
- Combination Drops: All these eye drops are also available in combinations, to reduce the number of drops patients need to use in their eyes.
Where eye drops fail to control the glaucoma or cannot be used because of developing allergy, surgery will need to be considered.
Closed angle glaucoma occurs when there is a mechanical problem with the drainage of fluid out of the eye through the “drainage angle” usually resulting from an increase in the size of the lens during middle age in patients with small eyes (hyperopia). Patients may have had previous ‘sub-acute attacks’ associated with blurred vision or haloes around lights or may present with an ‘acute attack’ and severe pain which may be enough to cause the patient to collapse. Treatment will depend on the case but most cases are treated by making a microscopic hole in the iris, a “Peripheral Iridectomy”, using the YAG Laser to bypass the flow of aqueous fluid through the pupil and prevent “pupil block”. Many patients require cataract surgery at some point following this and, where there is an element of chronic glaucoma may require surgery for this in addition.
Traditional glaucoma surgery, such as ‘Trabeculectomy’, consists of making a flap in the white of the eye, above the cornea, and allowing this flap to deliberately leak fluid under the surface covering of the eye (the conjunctiva) to reduce the pressure in the eye. Controlling the exact amount that the flap leaks is difficult and although the operation works well it does have a number of complications associated with eye pressure that is too low. In order to overcome this problem in 1997 Mr Peckar started using an operation called a ‘Viscocanalostomy’ developed by Professor Robert Stegman in Pretoria, South Africa, to reduce the problems associated with operations like trabeculectomy. Normal eyes are kept at a certain pressure by fluid being produced in the eyes and then draining away from the eyes through a system of fine channels (Schlemm’s Canal and the Collector channels). These fine channels drain into the venous circulation and this whole system prevents the eye pressure from rising too high. In open angle glaucoma there is a blockage to the normal exit of fluid into Schlemm’s canal and the collector channels and this causes the pressure to rise. In Viscocanalostomy the existing channels are opened up, within the eye, to reduce the pressure. The operation consists of making a small flap in the white of the eye to gain access to Schlemm’s canal which is then dilated through a small distance each side (5 – 8 mm). Viscocanalostomy is slightly limited, however, because the canal is a complete circle that runs all the way around the front of the eye collecting fluid throughout the whole of the circle. In“Canaloplasty” the operation starts as a Viscocanalostomy but then a small micro-catheter, similar to that used for dilating blood vessels in patients with heart disease, is passed through the whole of the canal. The canal is then dilated and a small stitch is placed into the canal, under tension, to keep the canal open (see video section).
Canaloplasty for Open Angle Glaucoma: A Three Years Critical Evaluation and Comparison with Viscocanalostomy:
"Viscocanalostomy and Canaloplasty are safe and effective surgical procedures for the management of Primary Open Angle Glaucoma with fewer complications than the current literature states for trabeculectomy. Moreover, when the results of these two groups of similar patients are compared, Canaloplasty produced significantly better results than Viscocanalostomy".
Combined cataract and glaucoma surgery
Viscocanalostomy and Canaloplasty may be carried out either on their own or combined with cataract surgery when indicated Phaco-viscocanalostomy [Phako-viscocanalostomy] and Phaco-canaloplasty [Phako-canaloplasty].
Dry Eye Syndrome
Dry Eye Syndromes are extremely common. Although the majority are seen in the elderly, as part of the aging process, they can occur at any age. The patient is aware of a gritty sensation in the eyes which tends to come on towards the end of the day and “makes the eyes feel tired”. The most common management of Dry Eye Syndrome is with the use of lubricants of which there are many types, both with and without preservatives. Different lubricants are appropriate for different patients and some will require the use of Sodium Hyuralonate drops or gel. For many patients the frequent instillation of ocular lubricants, for the rest of their life, is quite understandably seen as a burden and the use of intra-canalicular implants e.g. Thermodynamic Hydrophobic Acrylic Intracanalicular Implants may be their best option (see video section).
These are extremely common small cystic swellings of the meibomian glands, commonly infected and caused by an obstruction of the gland’s duct within the eyelid; they may be self limiting or may require a simple incision and curettage. In this procedure a small cut is made into the inner side of the lid, through the inner part of the eyelid. and the contents of the cyst and the cyst wall are removed under local anaesthetic.
This is a patch of thickened wing shaped conjunctiva which grows over part of the cornea in the exposed area between the two eyelids; it is commonest in the tropics due to the high ultraviolet light. Removal of the pterygium may be necessary when it is unsightly or encroaching on the centre of the cornea. Removal of the pterygium alone is associated with quite a high recurrence rate so excision is, therefore, best carried out in conjunction with a replacement using part of the patient’s own normal conjunctiva (from the area under the upper lid) “a conjunctival auto-transplant”.
These are small nodules adjacent to the cornea often precursors of a pterygium; they may or may not require removal.