What is Keratoconus?
Keratoconus is a progressive distorting disease of the cornea (the main objective lens of the eye). The disease is in the structural integrity of the cornea causing it to bulge in the centre, resulting in an irregular conical shape. As a result, the vision becomes increasingly distorted and may become severely blurred.
It is partially hereditary and it can also be caused by allergies and frequent eye rubbing. Keratoconus mostly happens to both eyes but often the progression is asymmetrical and the incidence of keratoconus is reported to be between 1 in 2000 to 1 in 500 people.
Course of events for keratoconus patients
Keratoconus symptoms usually begin during puberty or early adolescence. In most cases patients realise a decrease or blurring in vision. Keratoconus at this stage is difficult to differentiate from other more common vision defects.
In the early stages, a patient notices ghosting in spectacle corrected vision. The spectacles power then changes rapidly over months and years. Eventually the spectacles are no longer able to correct vision adequately and rigid contact lenses are required.
In around 10-20% of these patients even rigid contact lenses cannot correct their vision to driving standards or they cannot tolerate these lenses. Corneal surgery is then the only option left.
As this disorder often begins in adolescence, it can become a major problem for young people as there is a marked deterioration in the quality of vision as well as the quality of life at their most productive years of life.
To book your Keratoconus consultation or for more For more information on Keratoconus in Perth, call Aculase on (08) 9388 1828!
Can it be treated?
There is no cure for keratoconus and treatment in Perth is therefore aimed at improving vision and arresting disease progression. Depending on the degree of corneal bulging, thinning of the cornea and resultant astigmatism, the following options may be considered:
| Vision Improvement | Disease Stabilisation | |
|---|---|---|
| Spectacles | * | NIL |
| Rigid (Hard) Contact Lenses | * * * * | NIL |
| Corneal Ring Segment Implants | * * * | NIL |
| Collagen Cross-Linking (CXL) | * | * * * * * |
| Topographic-Guided PTK + CXL | * * * | * * * * |
| Corneal Transplantation | * * * | * * * * * |
Different treatments can be combined to improve overall result
Spectacles or Soft Contact Lenses
In the early stages, spectacles or soft contact lenses are sufficient to correct for the mild astigmatism. However, as the condition progresses, these methods are unable to provide the patient with an adequate degree of visual acuity. Soft contact lenses are usually no better than spectacles in keratoconus.
Rigid Contact Lenses
Subsequently, most clinical practitioners will then manage the condition with rigid (hard) contact lenses, known as rigid gas-permeables, or RGPs. RGPs essentially mask the irregularity by covering the keratoconic cornea with a new round rigid surface. Tears fill between the RGP and the cornea to complete the masking effect. RGPs provide a good level of visual correction, but they can be uncomfortable and they do not arrest the progression of keratoconus.
Topographic-Guided Laser Treatment with Collagen Cross-Linking (PTK+CXL)
The irregular keratoconic cornea is regularised by a laser treatment and then Collagen Cross-Linking is applied on the eye on the same day. The laser treatment is guided by a series of 3D scans of the cornea (topography). The aim of the treatment is to improve spectacle corrected vision. The patient will need glasses or lens implants after the procedure to capitalise on the improvement. Only a small amount of laser is applied so that the structural integrity of the cornea is not further compromised. CXL needs to be applied on the same day to strengthen the cornea.
Collagen Cross-Linking (CXL)
The primary aim of this treatment is to arrest keratoconus progression. CXL is a minimally invasive treatment whereby a form of Vitamin B drops is applied to the debrided cornea and then a laser-guided UVA light source is applied to activate a cross-linking reaction to the structural fibrils of the cornea. CXL can increase the structural strength of the cornea by 300%, thus arresting keratoconus progression.
The published results so far indicate an arrest of progression of this disease in over 90% of subjects. More than 50% of the subjects also have improvement in their vision following the treatment. The risk of the procedure is low.
Trans-epithelial Ionic Collagen Cross-Linking (IONIC CXL)
This is a non-invasive form of CXL. A special formulation of ionic vitamin B is used together with a small electrical current to drive the medication into the cornea without debridement of the corneal epithelium. A laser-guided UVA source is then applied to the eye for treatment effect. This form of treatment is essentially painless and allows for a very quick recovery. However, not all patients are suitable for this option.
Implantable Contact Lens (ICL)
Implantable Contact Lenses are soft thin lenses which can be inserted inside the eye to correct for refractive error permanently. It is good for correcting a high degree of astigmatism where spectacle correction to this degree is poorly tolerated by the patient. It is only suitable when the cornea is stable and has good spectacle corrected vision already. Therefore this form of treatment is usually suitable only after CXL or Corneal Transplantation Surgery.
Corneal Ring Segment Implants
Clear plastic segments are implanted into the cornea after a small tunnel is fashioned in the cornea. These ring segments aims to correct the irregularity and bulging to allow for better optical corrected vision. The recovery time is short and the treatment is reversible.
Corneal Transplantation
Corneal transplantation is viewed mainly as a last resort option where other treatment efforts are no longer viable.
Although corneal transplantation techniques have improved resulting in better long term safety and graft survival, it is still major eye surgery with significant risks and potential long term problems. Vision recovery is slow and it often takes 2-3 years to reach stable vision as sutures are left in the transplant for around 2 years.
Laser vision correction, implantable contact lenses and rigid contact lens may be applied to eyes after corneal transplantation once full recovery is obtained to improve vision.
Will Medicare or my Private Health Fund Cover these Treatments?
For Keratoconus treatment in Perth, Corneal Transplantation Surgery, Topographic Guided Laser Treatment, Corneal Ring Implants and now Collagen Cross-Linking (CXL) have a Medicare Benefit Scheme item number under certain circumstances. Therefore these procedures are partially covered by Medicare and Private Health Funds, provided the patient has taken up the appropriate hospital cover.
Book your consultation for Keratoconus in Perth at our Aculase clinic today!
