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. Anterior and or posterior surface of Cornea steepens and 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 and debatable though genetic predisposition is present. Several theories are built on research but none of the theories explain it all and it may be caused by a combination of several different factors like genetics, mechanical, inflammation, environmental and oxidative stress.
Chronic eye rubbing or inflammations have also been proposed to contribute in etiology of keratoconus . Some keratoconus are forme fruste or suspects and don’t need any treatment except yearly follow ups.
What are the symptoms of Keratoconus?
It may present as frequent change in spectacles power or patient not being comfortable with any type of spectacles. When the disease progresses, vision deteriorates and may not improve with spectacles.
Distortion of vision/ difficulty with spectacles /doubling of vision with one eye
Increased sensitivity to light/glare
Difficultly in driving at night
Eye strain
Headaches and general eye pain
What is the usual age of onset of keratoconus? How fast does it progress?
The age of onset of keratoconus can vary from early teens to people in their 40s or older.
Although cases in which keratoconus is first diagnosed at an earlier age usually result in more advanced progression,
it is not unusual for the disease to progress upto a certain point and then stablize.
The continued thinning of the cornea usually progresses slowly for 5 to 10 years and then tends to stop.
Occasionally, it is rapidly progressive.
Does keratoconus affect both eyes?
Yes, in approximately 90% of keratoconus cases the disease will manifest itself in both eyes.
The rate of progression and the timing of the onset of the disease however is typically different for each eye.
What is the treatment for Keratoconus?
Management of keratoconus is divided into two parts :
To stabilize the keratoconus and stop or delay the progression :C3R or collagen crosslinking with or without intacs (depends on type and severity of KC) .THERE IS NO TREATMENT TO REVERSE THE KERATOCONUS COMPLETELY.
Optical or visual rehabilitation: depending on the type and severity of keratoconus , the refractive error can be corrected by spectacles, specialized custom made contact lens or toric phakic ICLs. Early KC can be managed by correcting astigmatism with spectacles but as they progress patient may need to switch to RGP contact lens for better clarity.
Advanced severe KC may need lamellar or full thickness corneal transplant surgery
C3R (Corneal Collagen Cross linking with Riboflavin): This procedure 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 treated eyes.
Intacs: These are acrylic rings inserted in the corneal stroma to decrease corneal irregularity in cases of Keratoconus. They can improve uncorrected vision and can also be combined with C3R to flatten the cornea .
Rigid Gas Permeable Contact 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/Mini Scleral 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 your cornea.
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.
How is the C3R treatment done
The treatment is performed under anaesthetic eye drops.
The epithelium from 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 10 to 30 minutes by a special instrument. After the treatment,
a bandage contact lens is applied to allow the surface of the eye to heal. O
ral analgesics are required for the first 1 -2 days. There is no need for hospitalization after the treatment.
However, you will need to take rest for 2-3 days and use eyedrops .BCL is usually removed after few days .
There may be haze on cornea after CR3 and cause blurring of vision which resolves in few weeks.
1.Epilator Blade to remove corneal epithelium before dye instillation
2. Using corneal epilator to remove epithelium
3.Isotonic Riboflavin Dye
4.putting riboflavin dye on cornea
5.using well for riboflavin soak on cornea
6.Collagen Cross Linking -UV exposure thru riboflavin dye
7.Collagen Cross Linking -UV exposure thru riboflavin dye
8.C3R treatment in progress
9.Washing dye at end of procedure
When can I return to work after C3R?
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?
This treatment is known to stop or delay 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.
What are the advantages of C3R treatment?
Though this treatment will reduce astigmatism/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.
Are there any do’s and don’ts for keratoconus patients?
We allow all routine visual things and there is no restriction from screen time.
One important thing to remember is not to rub eyes as a habit or sleep with face down on pillows.
Both these things cause mechanical pressure on cornea over a period of time and can lead to progression of KC.
Do not ignore allergies -redness/itching of eyes and get them treated early as there is an inflammatory component in KC .
Yearly life long follow ups are required.
Will I go completely blind?
No, very very few suffer from total blindness from keratoconus alone,
specially if not detected in time. But in severe cases, one’s vision can be significantly
impaired and normal everyday activities may be difficult. However with the currently available treatment options
most patients retain useful vision enabling them to lead normal productive lives.