Keratoconus - C3R


 

 

What is Keratoconus?
This is a disease of the eye where the central mirror like structure , called Cornea, becomes weak, leading to progressive thinning and stretching which gradually progresses. Gradually, the Cornea bulges forwards, leading to an irregular cone shape. This causes distortion and blurring of the image formed by the cornea. Usually this disease is bilateral, though the severity may vary between the two eyes. Keratoconus affects about 1 in 7000 people.The cause is not known though genetic predisposition is present.

 

What are the symptoms of Keratoconus?
It may present as frequent change in spectacles power.. When the disease progresses, vision deteriorates and may not improve with spectacles. It also causes distortion in vision with multiple images, glare and sensitivity to light.

 

What is the treatment for Keratoconus?

  • Rigid Gas PermeableContact Lenses: Early Keratoconus can be managed by giving rigid gas permeable contact lens to the patient which correct the irregularity of the cornea and provide better quality of vision.
  • In advanced keratocnus these lens may not fit the eye optimally and become difficult to wear.
  • Rose K contact Lens /Scleral Boston contact lens:These are special custom made contact lens which give better fit and superior vision quality.These are ordered after taking various measurments of cornea.
  • C3R (Corneal Collagen Cross linking with Riboflavin): This is the only treatment to stop the progression of Keratoconus. It is based on collagen cross-linking with ultra-violet A (UVA, 365 nm) and Riboflavin (vitamin B2, a photo sensitizing agent). This changes the intrinsic biomechanical property of the cornea, increasing its strength by almost 300%. This increase in corneal strength has shown to arrest the progression of Keratoconus in almost all cases and it can reverse the Keratoconus changes by 20 to 30 percent.
  • Cornea Transplant: This is a surgical treatment, which is reserved for advance cases of Keratoconus, where the vision can not be improved with glasses or contact lenses. Here the central portion of the cornea is removed and replaced with a donor cornea of similar size. Since there is high possibility of complications & graft rejection, this surgery is done for selected cases.
  • Intacs: These are acrylic rings inserted in the corneal stroma to decrease corneal irregularity in cases of Keratoconus. They can improve uncorrected vision without contact lenses. These can also be combined with C3R.

CR3-Ultraviolet exposure after riboflavin dye on cornea

 

What is collagen cross-linking?
Collagen cross-linking is a non surgical treatment for keratoconus, that uses a photosensitizing agent, riboflavin (vitamin B2) & ultraviolet light (UVA, 365nm) exposure. In extensive experimental studies (including biomechanical stress & strain measurements) researchers have demonstrated a significant increase in corneal rigidity / stiffness after collagen cross-linking using this riboflavin/UVA treatment. The 3 & 5 year results of Dresden clinical study in human eyes has shown arrest of progression of keratoconus in all treated eyes.

 

Who is a suitable candidate for keratoconus?
We examine your eyes in detail to determine:

  • Patients with progressive Keratoconus
  • Minimum corneal thickness of 400 microns
  • Maximal keratometry readings < 60 D
  • No other corneal disease
  • Patients over the age of 16 years

 

How is the treatment done?
The treatment is performed under anaesthetic eye drops. The epithelium-front surface of the cornea is removed, followed by application of Riboflavin eye drops for 30 minutes. The eye is then exposed to UVA light for 30 minutes by a special instrument. After the treatment, antibiotic ointment is applied and a bandage contact lens applied to allow the surface of the eye to heal. Oral analgesics are required for the first 1 -2 days. There is no need for hospitalization after the treatment. However, you will need to use eyedrops and take rest for 2-3 days.

 

 

When can I return to work?
Your vision will remain blurred for 2-3 days after the treatment. So, you can work after 3 days.

 

When will my vision improve after the procedure?
Your vision will gradually start improving after a month and your contact lens fitting may change during this time. These changes continue even upto one year after the treatment.

 

Will I still need glasses and contact lenses after the treatment?
Though this treatment will reduce cylindrical power by couple of diopters and will improve the quality of your vision but you will still require corrective glasses or contact lenses, as the case maybe, though their power will change.

 

What are the advantages of C3R treatment?
This treatment is know to stop progression of keratoconus Patients will continue to wear spectacles or contact lenses (although a change in the prescription may be required) following the cross-linking treatment. The main aim of this treatment is to arrest progression of keratoconus, and thereby prevent further deterioration in vision and the need for corneal transplantation.