Specialty Contact Lens
fitting service
Visual performance of patients with irregular cornea or ocular surface disease usually cannot be improved by conventional spectacles or contact lenses. However, their visual function and quality of life may be enhanced by using specially designed contact lenses.
After a comprehensive eye examination, patients will be referred to specialty contact lens fitting service. The anterior ocular health of these patients will be further evaluated using advance technology such as corneal topography. The patients will be prescribed with custom-made specialty contact lenses according to the clinical findings and personal needs.
Corneal topography of irregular cornea
Severe keratoconus
What are the types and uses of
Specialty Contact lens?
There are different types of specialty contact lenses including multi-focal soft or rigid gas permeable (RGP) corneal lens, special designed tinted lenses, prosthetic contact lens, specialty RGP corneal lens, and scleral lens.
All these lenses have different clinical applications. For example, specialty corneal or scleral lens can neutralize the irregularities of the corneal surface and correct the refractive errors. Special designed tinted lenses can help patients to reduce visual discomfort and improve cosmetic appearance. After the ocular health and lens fitting assessments, optometrist will discuss with patients about the possible lens choices and fit them with suitable type of specialty contact lenses.
Who are the possible candidates
of the service?
1. Visual improvement
- Irregular Astigmatism is usually caused by irregular corneal surface due to corneal distortion. The visual performance of these patients cannot be improved by conventional spectacles or contact lenses. Common causes include keratoconus, pellucid marginal degeneration, and post-surgical complications (i.e. corneal transplant and LASIK)
- Refractive Errors includes patients with high myopia, astigmatism, presbyopia, or those who cannot achieve acceptable vision using normal visual aids (i.e. conventional spectacles and contact lenses) can consider using specialty contact lenses.
2. Cosmetic improvement
- Special designed tinted lenses can help patients to improve cosmetic appearance caused by opaque corneal scarring after trauma, inflammation or infection.
3. Ocular comfort improvement
- Special designed lenses can help patients to reduce ocular discomfort caused by anterior ocular abnormalities such as dry eye syndrome or abnormal iris appearance.
Fitting procedures of
Specialty Contact Lens
- Comprehensive eye examination
- Optometrist will provide professional advices about the available contact lens options based on patient’s ocular conditions.
- If patient are suitable for contact lens fitting, then we have the following contact lens fitting steps:
STEP 1. Optometrist will perform specific assessment to the patient to assess, for example:
- Anterior ocular health
- Contact lens clinical performance
- Lens curvature adjustment needed
- Lens comfort
- Visual performance
STEP 2. Contact lens delivery
STEP 3. Regular follow up and contact lens aftercare
Due to the large variety of specialty contact lenses and the complexity of lens fitting, the durations of trial fitting will be longer than conventional contact lenses and the lens performance can be varied among individuals.
Aftercare visits will be scheduled after successful contact lens delivery. The schedule of the aftercare visits may be varied among individuals, depending on the ocular conditions and lens performance in different patients. After achieving optimal lens performance, regular contact lens aftercare and follow up visits are still required, in general, once every three to six months.
(Information provided by The Hong Kong Polytechnic University Optometry Clinic.)