There are many eye conditions for while specialist contact lenses might be indicated. Some are more common than others. Here at Taylor-West & Sloan we specialise in all complex eye conditions, and have lenses to suit almost everyone. Please find below a summary of the main condition we tend to come across, but keep in mind this list isn’t exhaustive. If you suffer from an eye problem not listed here, please do get in touch to see if we can help you.
Keratoconus, literally meaning ‘cone-shaped cornea’, is a condition caused by thinning of the cornea, the clear front window of the eye, causing it to bow forwards. It affects around 1 in 2000 people in the UK and the cause is still not entirely understood, though there is a genetic link and a strong association with allergy and eye-rubbing. It is usually diagnosed in the late teens or early 20’s and continues to progress (worsen) until the early-mid 30’s, in most cases stabilising by the late 30’s.
When the cornea bows forward into an unnatural cone-shape, the light entering the eye is distorted. Instead of being focused into a nice, sharp image, the image is distorted and will often appear ‘smudgy’, ‘shadowy’ and ‘washed-out’. This is caused by irregular astigmatism and in many cases cannot be corrected with spectacles or regular contact lenses. Special contact lenses which help to mask the irregular shape of the cornea can usually provide a much clearer level of vision, restoring sight to a ‘normal’ level. Such lenses do not ‘treat’ the keratoconus, they simply correct the distorted vision whilst they are worn.
Some people require a corneal graft when their own cornea no longer provides any useful sight, either secondary to corneal diseases such as keratoconus or a corneal dystrophy, or scarring caused by trauma or infection. The central part of the defective cornea is either party or entirely surgically removed and replaced by donor corneal tissue, which is sewn into place. The resultant shape of the new cornea can vary widely. If the subsequent corneal profile is quite regular it may be possible to wear normal spectacles or standard contact lenses, or even go unaided. However many grafted eyes are quite irregular in shape, either because they are very flat, protruding, tilted or highly astigmatic. Such eyes can benefit greatly from specialised contact lenses, such as those described in the Contact Lens section of my website.
The vast majority of people who undergo refractive surgery (such as LASIK, LASEK, PRK, or Radial Keratotomy) end up with a very good result and excellent vision. However, with every surgery there is a risk and some people are less than happy with their results. In some unfortunate cases there can be extreme complications. The removal of too much corneal tissue can result in secondary keratoconus, or a distorted corneal surface. Even if the result is labelled ‘good’ and the visual acuity is ’20/20′, there can be problems with visual disturbances such as glare, starburst, ghosting and halos. Some actually have a very good result for many years, but their eyes change naturally and after a while they need a degree correction (this is quite common with radial keratotomy). This can be very difficult to achieve in some cases as after the surgery the cornea is no longer a ‘normal’ shape, and regular contact lenses may not fit properly. Through experience we have become quite adept at fitting such eyes with contact lenses, in many cases alleviating some or all or the undesirable visual affects of refractive surgery gone awry.
High Myopia, Hypermetropia and Astigmatism
Myopia (short-sight), hypermetropia (long-sight) and astigmatism are all types of refractive error. This is when perfectly healthy eyes are either slightly too large (in the case of short-sightedness), or small (in the case of long-sightedness). Astigmatism describes when there are different curvatures across the surface of the cornea, and can occur in conjunction with myopia or hypermetropia. When a prescription is over +/- 10 dioptres or the astigmatism is higher than around 4 dioptres, the prescription is regarded as ‘complex’. In many cases, with the range of modern disposable contact lenses we have available to us nowadays, these prescriptions can be corrected with standard lenses. However in some cases these standard lenses do not provide sharp enough or stable enough vision and that’s where I can help. Lenses such as RGPs, custom-made soft lenses, large diameter RGPs and hybrid lenses can often provide much crisper vision, which remains stable all day with no variation on blink or movement. The fitting of such lenses is often slightly more involved than the fitting of disposable lenses, but the results are worth it.
This list is not exhaustive. There are many other conditions that can be relieved by the use of contact lenses. These include:
- Corneal scarring/irregularity secondary to trauma or infection
- Presbyopia (the need for reading glasses one acquires with, ahem, too many birthdays!)
- Aniridia (cosmetic lenses can improve appearance and small-aperture opaque lenses can improve vision)
- Cosmetically poor eyes such as white corneal scarring or microcornea
- Ocular surface disease such filamentary keratitis, or severe dry eye secondary to Stevens-Johnson Syndrome or Sjogren’s Syndrome can be greatly relieved by scleral contact lenses