In the early stages of Keratoconus, a patient will generally notice a minor blurring of vision. At this stage the condition is often confused with that of an issue which require corrective lenses (w.r.t nearsightedness and farsightedness). However, as Keratoconus progresses to next stage, patients will find that their vision has deteriorated further. It results in distorted or blurred vision at all distances and poor night vision.
Generally, patients with Keratoconus will have very little or no pain. However, some patients develop sensitivity to bright light, have eye strain while trying hard to read objects. Also, patients with Keratoconus will find luminous object appear like a cylinder in shape with the same intensity at all points.
The causes for Keratoconus can be attributed to a number of reasons such as the following:
In the early stages of Keratoconus, a patient is prescribed eyeglasses or soft contact lenses, which shall help to correct the mild nearsightedness, blurring or distortion of vision.
In later stages of Keratoconus, when the cornea thins out and changes shape, rigid gas permeable (RGP) contact lenses and corneoscleral or miniscleral or scleral contact lenses are generally prescribed. These specialised contact lenses must be carefully fitted. Also, in order to maintain good vision, patient is required to undertake frequent checkups and lens changes. Other surgeries like Intracorneal ring segments (eg. Intacs) may sometimes be indicated to improve vision.
In progressive Keratoconus, Corneal Collagen Crosslinking with Riboflavin (C3R or CXL) is a treatment option to halt the spread of Keratoconus. C3R strengthens the weak corneal structure of Keratoconus patients. It is a non-invasive procedure (doesn’t require medical equipment to be introduced into the body).
In severe case of Keratoconus where vision cannot be improved using glasses or contact lenses, a Corneal Transplant may be needed. This is a surgical procedure that replaces the keratoconus cornea with healthy donor cornea tissue. Depending on the severity of condition either a full thickness Corneal transplant (Penetrating Keratoplasty) or a partial thickness Corneal transplant (Lamellar keratoplasty) may be indicated.
C3R is based on cross-linking of collagen fibers within cornea with ultra-violet light and Riboflavin (vitamin B2, a photo sensitizing agent). This changes the intrinsic bio-mechanical property of the cornea, increasing its strength by almost 300%. This increase in corneal strength has been shown to stop the progression of Keratoconus.
C3R is performed under topical anaesthesia with the patient in a lying down posture in the sterile environment of the operating room. The patient’s corneal epithelium is gently removed, then Riboflavin solution is applied every 5 minutes for the first half an hour. After that the patient’s cornea is exposed to ultraviolet light for half an hour. After the C3R treatment, a patient will be given a soft bandage contact lens and administered antibiotic drops.
The treatment is painless and lasts for an hour, at the end of which the eye is patched.
It is important to understand that the aim of C3R procedure is to try and stop the progress of Keratoconus and thereby stop further deterioration of vision. While C3R treatment generally does not lead to significant improvement in the inherent vision of the eye, however, as the corneal curvature flattens and the surface stabilizes, the best corrected visual acuity with spectacles and contact lenses improves. The overall fit of the contact lens also improves so that patient can experience much better quality of vision.
Immediately after C3R procedure the vision will be somewhat hazy or blurry. This is because after the collagen is cross linked its rigidity increases and the corneal transparency is affected. The vision will continue to fluctuate over the next 3 months as the process of cross-linking continues.
The patient will have to take prescribed eye drops for a few weeks. The patient is expected to see the doctor in the intervals of one week, one month and three months post-procedure. Once the vision stabilizes which is typically after a period of around 3 months, further treatment for visual improvement in the form of specialized contact lenses like RGP lenses or Scleral contact lenses can be prescribed.
C3R is a non-invasive procedure. There are no major risks associated. There may be a rare risk of corneal infection, which can be treated by the use of antibiotic eyedrops. In some cases there is a possibility of vision deterioration due to the occurrence of corneal scarring after C3R.
Disclaimer: All information, provided above is for informational purposes only and is not intended to serve as a substitute for the consultation, diagnosis, and/or medical treatment of a qualified physician or healthcare provider. Read our full disclaimer here.
