Symptoms of keratoconus
Keratoconus often affects both eyes, and the symptoms can differ from person to person. In its early stages, keratoconus symptoms can include:
- Mild blurring or vision
- Slightly distorted vision, with some parts clear and some parts blurry
- Increased sensitivity to light and glare
In a small number of cases, keratoconus continues to progress. Symptoms include:
- Very blurry and distorted vision
- Eye pain
- Increased near-sightedness or astigmtism
- Not being able to wear contact lenses, as they no longer fit properly
Keratoconus typically develops over a few years, but occasionally, it can progress quickly over several months. If you have any concerns about your eye health, you should see your optometrist.
Causes of keratoconus
Keratoconus is a complex condition and its cause is not yet understood. Although it has been thought that certain factors can play a significant role. These include:
- Family members who have the condition
- Underlying allergies
- Conditions that cause excessive eye rubbing – which could weaken the cornea
Your optometrist will review your medical history and carry out an eye exam. If keratoconus is suspected, measurements of the shape of the cornea, particularly over time, will help to determine if it is present.
Treatment for keratoconus
The best treatment for keratoconus will depend on its severity and how quickly it is progressing. You optician will be able to advise on what’s best for you.
Glasses or contact lenses can help with mild cases. For most people, their cornea will become stable after a few years and it’s likely that they won’t experience severe vision problems or require further treatment.
In a small number of cases, the cornea becomes so irregular and thinned that the cornea develops scarring and wearing contact lenses, even highly specialised ones, will not be possible. If this happens, you might need to consider surgery. You’ll be referred to see a specialist who will be able to determine the best type of treatment or surgery for you.
What contact lenses are best for keratoconus?
Rigid Gas Permeable Contact Lenses
Rigid Gas Permeable (RGP) contacts are often the first option for keratoconus. They are made of a rigid, breathable plastic that creates a tear layer that makes the shape of the cornea, correcting it to fit the natural shape of the lens. These contact lenses are easy to put in and out, and are relatively easy to look after. While contact lens wear increases the risk of an eye infection, with RGP lenses the risk is less. RGP lenses can be a little uncomfortable initially — especially for first-time contact lens wearers. If you find it too uncomfortable to wear RGP lenses for large amounts of time or if your keratoconus has worsened and RGPs no longer improve your sight, you might be offered another type.2
Scleral Contact Lenses
A scleral lens is a large, made-to-measure lens that sits on the sclera (the white of your eye), rather than on your cornea. As your sclera is less sensitive than your cornea, these lenses can be more comfortable for people with keratoconus compared to RGPs.2
Piggyback Contact Lenses
Piggybacking involves wearing a pair of soft contact lens underneath an RGP lens to act as a cushion. Although this involves more care and work, it can help to prevent the rigid lens from irritating the corneal surface and ease contact lens discomfort.
How can custom soft contact lenses help correct keratoconus?
Custom soft contact lenses can be used for those with mild‑to‑moderate keratoconus, who are unable to tolerate harder contact lens options. These contact lenses are made‑to‑order to ensure that they fit perfectly the wearer’s eye. They are specially designed to fit over the central steep part of the bulging cornea and have a variable lens thickness to neutralize the irregularity of the cornea. Since they are made‑to‑measure, keratoconus patients typically consider custom soft lenses to be the most comfortable contact lens option.3 Although they are not the typical choice for keratoconus patients, custom soft contact lenses can provide a good balance between comfort and vision correction.
If you do have keratoconus, then your first step should be to see your GP. They’ll be able to help you find the right lens for you. In the meantime, if you’re interested in learning more about contact lenses, head over to our contact lens resource for more information.
- American Academy of Ophthalmology. (no date). Keratoconus. [Online]. Available at: https://www.aao.org/eye-health/diseases/what-is-keratoconus [Accessed 5 November 2019].
- Rathi VM, Mandathara PS, Taneja M, Dumpati S, Sangwan VS. Scleral lens for keratoconus: technology update. Clin Ophthalmol. 2015;9:2013–2018. Published 2015 Oct 28. [Online]. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4630203/ [Accessed 5 November 2019].
- Rathi VM, Mandathara PS, Dumpati S. Contact lens in keratoconus. Symposium: Keratoconus. 2013; Volume 61; Issue 8; Page 410-415. [Online]. Available at: http://www.ijo.in/article.asp?issn=0301-4738;year=2013;volume=61;issue=8;spage=410;epage=415;aulast=Rathi [Accessed 5 November 2019].