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Post-surgery and irregular Cornea

Post-operative contact lens care

Today, surgical procedures on the eye are compulsive to save visual acuity, voluntary reasons to correct visual acuity. The most common voluntary reason is the well known laser treatment (such as LASIK). Examples of compulsive procedures include corneal transplantation for keratoconus where the condition has advanced to such a high stage that contact lenses no longer offer the best option. Other examples are procedures for eye injuries or infections or cataract removal

LASIK – correction of visual acuity

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The 95% success rate world wide for this surgical procedure is quite high. However this leaves a residual rate of 5% of patients with post operative problems.

Often sufferers complain about:

Halos, night blindness, dry eyes, foggy vision and poor visual acuity. These symptoms can be tackled by using eye drops or other medications, often in combination with glasses or contact lenses.

There may be other secondary effects after LASIK or similar procedures:

(1) The cornea develops an irregular surface:

  • Visual acuity decreases, astigmatism occurs
  • Halos, foggy vision

(2) Presbyopia occurs:

  • Need of reading glasses
  • Desire to wear multifocal contact lenses

Glasses become an option, however patients who entered into LASIK would probably want to avoid to wear glasses if possible. In this case a correction with multifocal contact lenses can show a better option.

The variety of different contact lenses on the international market is huge, but the difficulty is to find a lens suitable for a surgically treated cornea

SwissLens has taken this issue to heart, and it is now possible, with modern contact lens materials, to optimally correct a cornea which has undergone surgical laser treatment.

The “HydroMed” and “FlexMed” contact lens designs can offer both: good visual acuity and comfort – due to their back surface bicurve design, adjusted to take into account the central lasered corneal area.

Post Keratoplasty

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Normally, a keratoplasty (PKP) takes place in a late stage of keratokonus. As well as in case of high corneal irregularities or after infects, when there are no more options to correct visual acuity – only by transplantation of a new cornea.

During such operations it is very difficult to fix the graft on the remaining cornea leaving no residual vision errors, particularly irregular astigmatism. Therefore these patients could well benefit from a contact lens to improve their vision.

Irregular Cornea

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Irregular astigmatism is where the principal meridians are not perpendicular. It is often caused by an illness, an accident or an eye operation. In most cases, scarring on the cornea is an additional aspect that leads to the irregularity. The condition can lead to major limitations in vision, effecting daily work and a general reduced quality of life.

Causes of an irregular cornea:

  • Infectious diseases with corneal scarring
  • Injuries with scarring of the cornea
  • Extremely dry eyes with “Scouring” the eyelids
  • Surgical procedures, medically induced (e.g. keratoplasty for keratoconus) or aesthetic surgery (for example LASIK)
  • Conjunctival degenerations such as Pterygium

Types of surgery on the cornea

  • Myopia correction
  • Corneal keratoplasty, dystrophies and degenerational scarring
  • Tectonic keratoplasty to rectify severe corneal structural issues
  • Therapeutic transplantation for the removal of infected corneal tissue

Contact lenses for irregular cornea

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Traditionally special RGP contact lenses are recommended as a first choice in case of irregular corneas  after transplantation or grafting. Due to modern manufacturing technologies combined with advanced material technologies it is possible, now, to considere soft contact lenses as a viable alternative.

For example the classic RGP scleral lens which overlies only¬† the conjunctiva to “bridge” the cornea entirely;

customized soft lenses can now be adjusted as well due to a nano-metric level. The made to measure lens-surface can modellise nearly all irregularities of cornea. With a high oxygen permeable material like silicone hydrogel the possibilities for greater patient satisfaction and improved clinical results cannot be ignored.