MEDICAL CONTACT LENS SERVICE

The Medical Contact Lens Service provides lenses for medical and therapeutic indications and manages complications related to contact lens wear.

Medical Indications

In this group of patients, usually the vision cannot be improved with spectacles but can be improved with contact lenses. These conditions include:

• Irregular corneas or scarring (for example – keratoconus, corneal trauma, corneal graft surgery, or after corneal infections)
• Complex spectacle prescriptions – high short or long-sightedness (e.g., more than 1000 degrees), high astigmatism or anisometropia (large difference in the degrees between the two eyes)

Therapeutic indications

Here, the contact lens is used to treat various conditions. Examples are:

• Pain relief in patients with bullous keratopathy (swelling of the cornea), corneal abrasions, epithelial defects and post-surgical conditions
• Enhancement of corneal wound healing usually in post-surgical conditions such as following corneal transplantation procedures, post LASIK, and in persistent epithelial defects

Prosthetic lenses are also available for eyes that are unsightly following damage or injury.
 
Soft lenses and rigid gas permeable (RGP) lenses are the main lenses available. Each has specific indications as well as a specific wear and care regime. Types of soft lenses include conventional and frequent replacement or disposable lenses. A range of contact lens materials and designs are available to suit the wearer. Soft lenses are made of a range of hydrogel polymers. More recently, the incorporation of silicone into the hydrogel polymers (silicone hydrogel polymers) significantly increased the oxygen permeability of the lens material. Rigid gas permeable lenses are made of silicone acrylate polymers which are more oxygen permeable than soft hydrogel lens materials. 
 
Soft and rigid lenses are usually worn to correct refractive errors like myopia, hyperopia, astigmatism and presbyopia. In addition, a wide range of rigid lens designs including scleral lenses are available to correct complex corneal conditions such as keratoconus, corneal scarring and post-corneal surgery including corneal transplantation.
 
Complications arising from contact lens wear range from mild conditions like dry eyes and allergic conjunctivitis to potentially sight-threatening conditions like infective corneal ulcers. The risk factors for infective corneal ulcers include poor compliance with lens care instructions and poor hygiene, long duration of lens wear and overnight wear of lenses.
 
Symptoms of infective corneal ulcers include eye pain, redness, discharge and blurring of vision. If you experience these symptoms, you should remove your contact lenses and seek medical help immediately. Early appropriate medical treatment of infective corneal ulcers is usually more effective than late treatment. When medical treatment fails to control the corneal infection, a therapeutic corneal transplantation procedure may be required.
 
Proper fitting, instruction, care and maintenance can prevent most contact lens wear problems. Most types of contact lenses except daily disposable lenses require regular cleaning and disinfecting in order to retain clear vision and prevent discomfort and infections. To ensure successful lens wear, it is important to practise good hand hygiene and follow the lens care instructions of the cleaning and disinfecting solutions used. Regular eye examination by your eye care practitioner is also important as certain contact lens complications may not have symptoms.

Please visit the following relevant links:

Outcome Results on Corneal & External Eye Disease Procedures
Corneal & External Eye Disease Clinical Staff
I Want an Eye Examination / an Appointment
Care After Corneal Transplant
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Read more on related Eye Conditions and Treatments:

Corneal Infections
Dry Eye
Eye Infections
Pterygium