What Is Keratoconus?

What Is Keratoconus?

Definition of Keratoconus: The term keratoconus is derived from Greek and Latin. Kerato means cornea and conus indicates cone formed. It is a bilateral, progressive, uneven, non-inflammatory thinning and ectatic problem of the cornea, ensuing in a large degree of irregular myopic astigmatism.

Prevalence: Keratoconus is approximated to arise in 1 out of each 2000 people in the common population. There appears to be no significant preponderance with regards to both adult men or females.

What is the usual age of onset of keratoconus?

The onset of keratoconus is amongst the ages of 10 and 30. The alterations in the condition of the cornea commonly arise slowly but surely more than several yrs.

Symptoms: Signs or symptoms depend on the severity of the condition. The most common indications include:

• Blurred eyesight.

• Distortion of vision.

• Photophobia.

• Glare.

• Eye Irritation and itching.

• Frequent spectacle ability improvements.

• Incapability to put on get hold of lenses.


The bring about of keratoconus stays unidentified, whilst latest exploration looks to point out the doable causes include:

• Keratoconus is believed to contain a defect in collagen, the tissue that would make up most of the cornea.

• Keratoconus have a genetic part and reports suggest that about 8% of people have influenced kinfolk.

• It occurs a lot more normally in men and women with selected clinical difficulties, such as selected allergic disorders.

• Some feel that long-term excessive eye rubbing can result in of keratoconus.


(A)Primarily based on keratometry examining:

1. Moderate: Keratometric readings are considerably less than 45D in each meridians.

2. Moderate: Keratometric readings are amongst 45D and 52D in both equally meridians.

3. Superior: Keratometric readings are concerning 53D and 62D in both equally meridians.

4. Serious: keratometric readings are in each meridians much more than 62D.

(B)Primarily based on morphologic form:

1. Nipple Cones: Characterised by their compact dimension (5 mm) and steep curvature. The optical centre is generally both central or para-central and displaced inferonasally.

2. Oval Cones: Which are greater (5-6 mm), ellipsoid and typically displaced inferonasally.

3. Globus Cones: Which are largest additional than 6mm and could require above 75% of the cornea.

Medical Features:

1. In early stage, impaired vision in a person eye induced by progressive Irregular myopic astigmatism with steep keratometry studying.

2. Scissor reflex on retinoscopy.

3. Ophthalmoscopically exhibits an “Oil droplet reflex”.

4. Munson indicator-Bulging of reduced lid in down gaze.

5. Fleischer Ring-Epithelial iron deposits at the foundation of the cornea. Mechanism of iron deposition is not clear recognized. It may be uneven distribution of tears.

6. Progressive Central or paracentral stromal thinning with inferior apical protrusion.

7. Vogt striae-Fine deep vertical stromal folds which temporarily vanish on digital stress.

8. Rizutti indicator-conical reflection on the nasal cornea when gentle is shone from the temporal side.

9. Distinguished corneal nerves.

10. Acute Hydropes-Corneal edema resulting from tears Due to ruptures of the descemet`s membrane and acute seepage of the aqueous humor into the corneal stroma and epithelium. These breaks generally recover within just 6-10 weeks and the edema step by step clears.

11. Variable corneal scarring, based on severity of the illness.

Associations: The ocular and systemic associations of the keratoconus include things like:


• Vernal conjunctivitis.

• Blue sclera.

• Aniridia.

• Ectopia Lentis.

• Retinitis Pigmentosa.

• Leber congenital amaurosis.


• Down syndrome.

• Ehlers-Danols syndrome.

• Marfan syndrome.

• Atopic dermatitis.

• Osteogenesis imperfecta.

Tests and Tests:

Visual acuity screening: Visible acuity is an indicator of the clarity or clearness of one’s eyesight. It is a measurement of how well a person sees.

Refraction: The refraction test is an eye test that actions a person’s prescription for eye eyeglasses or speak to lenses.

Slit Lamp evaluation: The slit lamp is an instrument consisting of a large-intensity light resource that can be targeted to shine a thin sheet of light-weight into the eye. The slit lamp examination presents a stereoscopic magnified look at of the eye buildings in depth, enabling anatomical diagnoses to be created for a range of eye problems like keratoconus.

• Corneal topography: Corneal topography, also regarded as photokeratoscopy or video-keratography, is a non invasive imaging strategy for mapping the floor curvature of the cornea. The 3-dimensional map is a precious support. It is also employed in the diagnosis and procedure of a range of conditions in preparing refractive surgical treatment such as LASIK and evaluation of its final results or in assessing the match of get hold of lenses or to diagnose keratoconus.



Spectacles: In the early levels of the keratoconus, spectacles are normally thriving in correcting the myopia astigmatism affiliated with the keratoconus. But in serious circumstances it does not give great high quality of vision due to significant amount of money of corneal toricity.

Speak to lenses:

1. Tender make contact with lenses: In the early stages of the keratoconus gentle get in touch with lens is beneficial. Simply because soft call lens give fantastic ease and comfort. But in advanced levels tender get in touch with lenses cannot right irregular astigmatism. So, soft make contact with lenses are not handy in highly developed phases of keratoconus.

2. Rigid Gasoline Permeable contact lenses (RGP): As the problem developments, the cornea will become highly irregular and vision is no for a longer time sufficiently corrected with spectacles and delicate speak to lenses. Rigid gas permeable speak to lenses are then essential to deliver ideal visual acuity. Rigid gasoline permeable lenses enables to vault above the cornea, replacing cornea`s irregularities by filling tears among cornea (front area of the eye) and back floor of the RGP lenses with a sleek, uniform refracting surface area to strengthen eyesight.

3. Piggy again get hold of lenses: Suitable fitting of a rigid gasoline permeable call lens over a cone-formed cornea can occasionally is not probable. To get excellent fitting and excellent visible consequence some practitioner use piggyback contact lens. This technique consists of positioning a soft make contact with lens, these as 1 designed of silicone hydrogel, over the eye and then suit a RGP lens about the delicate contact lens.

4. Rose-K Lens: Rose-k lens was launched by Dr Paul rose in 1995. This lens is world’s most often approved gas permeable lens for keratoconus. This lens has advanced geometric layout. In this article 6 diverse curves at again surface area of the lens and lowering optic zone as base curve steepens. The content of the lens is Boston.

5. Boston sclera get hold of lens: In progress case of keratoconus to delay the surgical procedures Boston sclera get hold of lens is extremely handy. It is produced of content that will allow oxygen to go through to the eye, more substantial diameters (15 to 24mm), edges rest on the sclera or white part of the eye and the central optic zone (12mm) is made to totally vaults more than the irregularly formed cornea. These larger sized lenses also are much more secure than standard fuel permeable contact lenses.


Penetrating Keratoplasty: In about 15% of conditions, the keratoconus progresses to the phase exactly where corneal transplantation is expected to reach superior eyesight.

Corneal Collagen Cross-linking with Riboflavin (C3-R): A new, minimally invasive process named Corneal Collagen Cross-linking with Riboflavin (vitamin B) and ultraviolet-A (UVA 365nm) is identified as C3-R.

The treatment is done in operation theatre below full sterile situations. Generally 1 eye is addressed in one sitting down. The procedure is carried out employing anesthetic eye drops. The surface area of the eye (cornea) is addressed with software of Riboflavin eye drops for 30 minutes. The eye is then exposed to UVA gentle for 30 minutes. The mix of Riboflavin drops and extremely violet light that respond with the tissues in the cornea, strengthening them by producing additional ‘cross-linking’ between them. The ensuing greater stiffness and rigidity of the cornea, stabilizes corneal ectasia. For this reason, the therapy usually takes about an hour for each eye. Just after the treatment method, antibiotic eye drops are utilized a bandage speak to lens could be utilized, which will be eliminated soon after couple days.

On the other hand one particular have to have to understand that Collagen cross-linking procedure is not a heal for keratoconus, fairly, it aims to gradual the progression of the ailment. However adhering to the cross-linking procedure it helps make the affected person extra comfortable to have on call lens.

Troubles of keratoconus:

• Patients with even borderline keratoconus really should not have laser eyesight correction. Corneal topography is performed just before laser vision correction to rule out people today with this ailment.

• There is a threat of rejection after corneal transplantation, but the risk is significantly decreased than with other organ transplants.

When to Contact a Clinical Experienced?

Young folks whose eyesight are unable to be corrected to 20/20 or 6/6 with glasses need to be evaluated by an eye medical doctor expert with keratoconus.

Does keratoconus have an affect on both of those eyes?

Certainly, keratoconus typically impacts the two eyes. Keratoconus is generally a bilateral problem the degree of progression for the two eyes is often unequal.

Does keratoconus induce blindness?

Keratoconus does not trigger total blindness. Having said that it can lead to sizeable eyesight impairment ensuing in legal blindness.


There are no preventive measures. Some specialists consider that individuals with keratoconus need to have their eye allergies aggressively dealt with and must be instructed not to rub their eyes.