Other Eye Surgery Options
Refractive Eye Surgery is not always the best treatment for some patients so below we have listed some other forms of Refractive Eye Surgery Procedures & alternatives to the standard Lasik, Lasek, Wavefront, IntraLasik & PRK eye surgery procedures that are most commonly performed in UK Clinics.
REFRACTIVE Surgery PROCEDURES
This text only serves as a guide and introduction to surgery procedures used in the ophthalmic world. Not all eye surgery procedures are listed as they are too numerous to detail. The more popular ones are described below.
Please note, this is only a guide and is NOT a recommendation. You are advised to obtain specific advice from YOUR ophthalmic surgeon with regards the risks, benefits and alternatives of laser eye surgery procedures being advised.
LASIK Laser Eye Surgery:
Laser in situ Keratomileusis
PRK Laser Eye Surgery:
LASEK Laser Eye Surgery:
Laser subepithelial keratomileusis
Alcohol is used to stun the epithelial cells, breaking their adhesions with the underlying layer thus enabling this layer to be removed and then later replaced after laser treatment.
>Subepithelial keratomileusis that uses a mechanical keratome to delaminate (separate and peel back) the outermost layer of the cornea. Following laser ablation and change in shape, this is then replaced
Advantage: As opposed to LASEK eye surgery, the cells are not harmed by alcohol and are live
Disadvantage: Bowman's layer is still removed and there is still a risk of haze. This eye surgery procedure is very new and it will be interesting to see if the outcomes are any better than LASEK laser eye surgery or PRK laser eye surgery.
Colloquially known as the "Russian procedure" of which there are two techniques: American and Russian. The eye surgery procedure is "quick and dirty" and works by making the cornea bulge in the periphery and flattening the centre. Incisions to 90 to 100% depth of the cornea are made using a Diamond blade knife. The cornea is PERMANENTLY weakened and can be ruptured from a knock to the eye. The procedure does not meet the safety and stability standards of other eye surgery procedures like Lasik laser eye surgery . Progressive hyperopia ( a drift towards plus) occurs in 30% of patients. This is a disaster as the subjects will require glasses for reading at an earlier age and in time require glasses for both reading and distance Other problems include:
a) Permanent Starbursts
b) fluctuation of vision throughout the day and
c) poor vision at high altitudes, so don't try climbing Mt. Everest !
General consensus by the ophthalmic community is this eye surgery procedure has had its day and should not be used if some of the alternatives listed above are available. The procedure is certainly not current standard of care
ASTIGMATIC KERATOTOMY (AK)
This eye surgery procedure is used to correct astigmatism alone. It uses a Diamond knife to make carefully planned circular or straight incisions in the axis of astigmatism to decrease the amount. Most commonly used in conjunction with Radial Keratotomy, however DOES have a place in modern refractive practice, particularly in patients who have had corneal grafts and have high levels of astigmatism.
LIMBAL RELAXING INCISIONS (LRI)
Similar to Astigmatic keratotomy, deep incision are made at the Corneo-scleral junction to relax the cornea where it is steep. This results in a decrease in Astigmatism. Most commonly used in conjunction with cataract surgery or refractive lensectomy (see below).
PERMAVISIONTM Corneal Inlays
This CE marked device is made of a highly biocompatible material called Hydrogel which has been adapted to mimic the cornea. It is placed in the cornea under a Lasik flap and can be removed or replaced. It has been used to treat Hyperopia (Farsight) and is in Phase II human clinical trials in the USA. Three year data is now available.
Advantage: A reversible procedure
Disadvantage: Only available for Farsight (Hyperopia)
Some reports of decentration and mild haze in some individuals.
Rings are inserted into the cornea outside the pupil. They work by flattening the central cornea and suitable for low level of myopia. They are also being used more now in the treatment of Keratoconus a disease where the cornea bulges and has a cone like shape. Two types are available:
Ferrara: Invented by Paolo Ferrara from Brazil, the diameter is 5 mm and the cross section is triangular and works like a prism reflecting away light that hits the rings, thereby preventing edge glare from the device. The small diameter makes the device highly effective and as it is further away from the sclera there is less chance of attracting blood vessels.
Intacs: This device generated a great deal of excitement a few years ago, but the eye surgery procedure never really took off and the company Keravision went into receivership. The product is now manufactured by Addition Technology Inc. and much work is being directed to providing a treatment for Keratoconus. The devices are inserted into the cornea in a similar fashion to the Ferrara ring, however they are 7mm in diameter and closer to the sclera and less effective.
INTRAOCULAR EYE SURGERY PROCEDURES
REFRACTIVE LENS EXCHANGE
Essentially the same as cataract procedure which involves entering the eye and removing the crystalline lens and replacing this with an implant. To correct refractive error, the implant is calculated specifically for each eye using a variety of methods (laser interferometry and/or ultrasound) to measure eye dimensions ( eye length and anterior chamber depth) and this is in turn used to calculate the power required. Until recently the implants used were only available for one focal length. If set for distance, then the subject would require reading glasses for near vision. Now with better understanding and newer technology, implants are available that provide both near and distance focus. These implants are either MULTIFOCAL or ACCOMMODATIVE (see below).
This type of surgery carries its own sets of risks, which although very low in frequency can be quite significant. Amongst the most serious risks are: infection, haemorrhage, problems at the time of eye surgery that can lead to a less than ideal outcome (i.e. surgery not going right) and retinal detachment. Advantages of this type of surgery are extremely good quality of vision, especially for high levels of correction and now the ability to read close up as well as see in the distance without correction. The procedure is best performed in individuals over the age of 55 for shortsight and 50 for those with high levels of far-sight (author's preference).
ACCOMMODATIVE and MULTIFOCAL IMPLANTS
These are implants used in Cataract and Refractive lens exchange. The term PRELEX (Presbyopia Lens Exchange) has been used in this context with this type of implant. The concept is to replace the crystalline lens or cataract with an implant that is able to provide patients with the ability to read and see at distance without correction
ArrayTM AMO - this has a series of annular rings that provide different focussing powers to enable subjects both distance and near vision. Patients need to be selected well and must be prepared for a period of adaptation over 3 months. Contrast sensitivity is not as good as there is a degree of interference from the different focal rays.
Crystal LensTM C&C Vision - invented by a British eye surgeon who went across the Atlantic (Stuart Cummings). This device actually moves in the eye and provides accommodative power just like we have in our early years. Eye Surgeons have to be obsessive about lens calculation as well the operative procedure to ensure the device works properly. The device does work and is the first of its kind to receive approval from the US Food and Drug Administration (FDA). Restoring the power of accommodation takes time in some patients (up to 3 months) and requires practice to ensure muscles not used for decades start functioning again. The level of satisfaction among patients after this eye surgery procedure is outstanding.
1CU LensTM - Human Optics - this is another accommodative implant made by a company in Germany. Data looks encouraging and again similar aspects with regards to attention to detail and practice by patients apply.
These are lenses that are implanted in the eye WITHOUT removing the crystalline lens. This type of device is used in patients who are outside the range of correction by LASIK eye surgery or not suitable for other reasons. There are a variety of devices available and more coming on the market. They each have their advantages and disadvantages and a number of eye surgeons have their preferences. All involve entry into the eye (carrying its own risks) and implantation in either in the very front (VIVARTE), on the iris (ARTISAN or VERISYS), or behind the iris close to the crystalline lens (ICL or PRL).
ARTISANTM - Opthec or VERISYSTM - AMO
These two lenses are identical. AMO are licenced to manufacture the Artisan under another name. The lens is attached to iris and is extremely stable as long as it has been implanted properly. Suitable candidates must have a healthy cornea (determined at consultation) and must also have adequate space for the lens without causing long term damage. This phakic implant has been implanted in more patients than any other and has a long track record. Comparative studies using this lens and two others, have demonstrated greater overall safety. The ARTIFLEX foldable lens is under investigation and will permit implantation through a very small incision.
VIVARTE, NUVITA (not manufactured anymore)
This lens invented by French ophthalmologist George Baikoff has gone through several incarnations. This one is a foldable implant that sits in the anterior chamber supported by the angle where the iris root attaches to the eye. Its close proximity to the cornea can lead to corneal damage as well as iris trauma and oval or cat's eye pupils. Patients have been reported to develop Glaucoma. Sizing of the lens and precise implantation are vital for success and in spite of this can still lead to problems.
ICL - Staar Surgical and PRL - Ciba Vision
Both lenses are implanted behind the iris with a small fluid space between the lens and the crystalline lens. This space is important to prevent cataract formation. The ICL or implantable contact lens has gone through 4 major incarnations with the latter demonstrating greater overall safety. Visual quality is excellent, however long term development of cataract remains a concern as does Glaucoma. The PRL or Phakic Refractive Lens, is similar to the ICL except smaller in dimension and held in place by movement of fluid in the eye as well as the iris. The lens is currently under investigation with only short term data available.
The author wishes to emphasise again the fact that the success of the above procedures, like laser vision correction is highly dependent ( probably more so) on the surgeon performing the consultation and procedure. Attention to detail is important and proper understanding of risks, benefits and alternatives is vital.