Contact Lenses

Contact Lenses
Contact lens services available at the Pacific University College of kinoshitaOptometry Family Vision Centers include: the fitting and management of contact lenses for refractive conditions such as nearsightedness, farsightedness, astigmatism, and presbyopia. Each of these conditions can be treated with a variety of lens types and materials.

Our therapeutic specialty clinic provides care for those individuals with medically necessary contact lens needs, such as Keratoconus, Post Corneal Transplant, or an irregular corneal surface.

                                                                    

Beth Kinoshita, OD, FAAO

Chief, Contact Lens Service

                                                              


Soft Contact Lenses (SCL):

This type of contact lens is relatively soft and flexible, which allows it to drape over the entire surface of the cornea like a blanket. There have been many advances in technology and materials in the past few years, making contact lens wear healthier for the eye and more comfortable for the patient. Advantages of this type of lens include disposability, shorter adaptation time, and the ability to enhance or change eye color.


Rigid Gas Permeable Lenses (RGP):

These lenses are relatively smaller in size and are less flexible than a soft contact lens. RGP's are composed of a low flexure plastic polymer with a water content of <2%. This type of lens offers high optical quality, superior ocular health, easy care regimen, and durability.


Correction of Astigmatism:

Astigmatism includes refractive conditions in which the optical system of the eye cannot create a single point image on the retina from a single point object in real space. This situation usually arises when the cornea has two different curvatures which focus light at two different places on the retina. Correction is needed to focus those two points of light into one sharp image. Toric soft contact lenses, as well as rigid gas permeable lenses can be used to compensate for this type of refractive error.


Correction for Presbyopia:

As the eye ages, it slowly loses the ability to focus on objects held at arms length or closer. Patients who are becoming presbyopic may want to consider the use of contact lenses (SCL or RGP) instead of spectacles. There are several management strategies that can be used in the correction of presbyopia.


Monovision: The most common type of correction for presbyopia with contact lenses involves two different focal distances. One eye is focused for distance viewing and the other eye is focused for near viewing.
Bifocal Contact Lenses: There are both soft contact lens bifocal designs and rigid gas permeable lens design. Some lenses contain a visible segment area for near viewing, while others incorporate the progressive or no-line design. Selection is based upon the type of lens which will provide the patient with stable and comfortable vision specific to his or her needs. Some lenses contain a visible segment area for near viewing, while others incorporate the progressive or no-line design. Selection is based upon the type of lens which will provide the patient with stable and comfortable vision specific to his or her needs.


Wearing Schedules:
 
The amount of time a lens is worn each day and the frequency with which it is replaced is dependent upon many factors, such as doctor’s recommendations, ocular health of the eye, patient convenience and compliance with lens care regimen. Realistic patient expectations about lens performance and the maintenance of good ocular health are among the primary goals for successful contact lens management.


Daily Wear: With this schedule, the lenses are worn for an average of 12 hours per day and then removed at night. After removal, the lenses are cleaned, disinfected, and stored prior to re-insertion the following morning.


Extended Wear: These lenses may be worn overnight for 1-6 consecutive nights. Soft contact lenses in this category generally have a higher oxygen permeability than daily wear contact lenses and are made of silicone hydrogel material. This wearing schedule can create a greater risk (8 times greater compared to the daily wear schedule) of infections, including sight threatening corneal ulcers. Some RGP's can also be used on an extended wear basis. An example of this is in orthokeratology.


Daily Disposable Lenses: Disposable lenses are designed to be discarded upon removal rather than cleaning, disinfecting and storing the lens. A fresh lens is used each morning. Some advantages of this modality are that a new lens is placed on the eye every day and there is no need for solutions.


Frequent or Planned Replacement Lenses: This category includes 2-week, 1-month, quarterly and 6-month replacement lenses. These lenses must be cleaned and disinfected each night prior to storing. Planned or frequent replacement schedules can be beneficial for patients who experience comfort and vision problems created by excessive lens deposits, typically protein build-up. The insertion of a fresh lens can relieve these symptoms as well as reduce the potential for inflammation or infection.

SPECIALTIES:

Therapeutic Contact Lens Clinic:
 
Treatment of certain patients with corneal dystrophies or degenerations such as Keratoconus may involve the use of specific RGP or specialty soft contact lens designs. Post-surgical and post-trauma patients can also benefit from contact lenses designed for their specific needs.


The Contact Lens Specialty Service at Pacific University was established in 1996. Our goal is to provide patients with the latest advances in contact lens technology. The services we offer in our specialty clinics include contact lenses for a wide range of conditions that include:
Keratoconus and Pellucid Marginal Degeneration: This is a non-inflammatory, self-limiting corneal disease involving progressive thinning, steepening, and distortion of the cornea. The resulting loss of optical quality in the cornea is improved best with RGP lenses specially designed for the patient.

Post-Surgical: Patients who have had refractive surgery such as RK, PRK, and LASIK may need to improve their vision to a more desirable level with contact lenses in some cases. For patients who have had non-refractive surgery, such as a corneal transplant, a contact lens may be the best way to enhance vision.

Aphakia: Both pediatric and adult aphakia is the absence of a lens inside the eye.

Post-Trauma: Corneal defects (such as abrasions, recurrent erosions and lacerations) caused by the introduction of a foreign body or substance into the eye may be managed with the use of contact lenses.

Aniridia: Absence of an iris. Patients with iris abnormalities from trauma or congenital forms like anirida can benefit from prosthetic contact lenses which artificially simulate the pupil. Opaque contact lenses can also be used as an alternative for patching in Vision Therapy.

 

Other services that we offer are:

Orthokeratology: The use of a specially designed RGP for over night wear that reshapes the corneal curvature to provide clear vision during the day without the use of a contact lens or glasses.


Sports Vision: This includes specially tinted lenses that are used during specific sport activities, such as golf, soccer, baseball, or running. The tint is determined by the visual demand of the particular activity.


The specialty lens designs we offer include:
· Gas Permeable Lenses

· Custom Soft Contact Lenses

· Hybrid Lenses

· Semi-Scleral Lenses

· Piggyback Lenses

· Reverse Geometry Lenses