World Keratoconus Day is a chance to raise extra awareness of the disease and this year falls on 10th November. Keratoconus is a disease of the cornea which is progressive but non-inflammatory. Keratoconus is caused by weakening of the collagen fibres which would normally maintain the cornea’s dome-like shape. With this disease the weakened cornea starts to thin, change shape and bulge outwards. This bulging and thinning causes the cornea to form a gradual cone shape which can severely affect vision.
An initial sign of keratoconus is often changes in prescription. Also, many patients experience visual disturbances such as glare, halos and double vision which is due to the cornea changing shape. Overtime patients with keratoconus notice their vision starts to become distorted and blurry, and as this is a progressive disease, these visual symptoms become worse. Many patients with keratoconus tend to be very near-sighted with a high level of astigmatism. Initially glasses and contact lenses may help with the visual changes but as the disease gets worse glasses and contact lenses lose their helpful effects. Opticians tend to refer a patient on to an ophthalmologist if these signs start to occur and worsen, the ophthalmologist will then diagnose the condition and devise a treatment plan.
Keratoconus can occur for many reasons, but the cause is still unknown. The disease can run in families and may develop from an early age, for this reason it is recommended getting children’s eyes checked by an ophthalmologist if the disease does run in the family. It may also develop at a later age due to; chronic eye rubbing or laser eye surgery (called ectasia) for example. There are also some other medical conditions where a patient may be more likely to develop keratoconus such as; retinitis pigmentosa, Ehlers-Danlos syndrome and Down’s syndrome.
Treatment for keratoconus varies due to the severity of the disease. As mentioned above glasses or soft contact lenses are initially recommended to help with the visual changes, but as the disease progresses switching to hard or other specialist contact lenses may be favourable to get better vision. These type of contact lenses must be correctly fitted and having follow ups to monitor the vision and status of the cornea is essential. If glasses and different types of contact lenses do not work, and as the disease continues to develop, a procedure called corneal collagen cross linking may be advised by a corneal doctor. This procedure, now recommended by the National Institute for Health and Care Excellence (NICE), helps to slow or stop disease progression. It works by using an ultraviolet light and riboflavin (vitamin B2), to help build and straighten the weakened collagen fibres by creating more cross linking between the fibres of the cornea, making it stronger and more ridged. Corneal collagen cross linking can be done on children and adults alike and is fast becoming ophthalmologists procedure of choice to treat keratoconus due to its safety and efficacy. Other options for treating keratoconus can also include corneal ring implants, which helps to support the cornea’s natural shape, and phototherapeutic keratoplasty (PTK) may also be suggested. If the disease is too advanced and severe the treatments above may not help, and the only option may be for the patient to have a corneal transplant, this can either be a partial or full thickness transplant and only used as a last resort if other treatments cannot help.
Keratoconus is a serious eye disease and can be blinding if not monitored and treated correctly. Currently there are no cures for the disease and the only treatment to help slow or stop keratoconus is corneal collagen cross linking. It is advised that patients, adults and children, with keratoconus or suspected keratoconus attend their follow up appointments and keep to the advice of their optician or eye doctor.