Specialty Contact Lenses for Keratoconus & Irregular Corneas: RGPs, Hybrid Contacts, Scleral Lenses

TopographerA computerized corneal topographer is a special non-invasive instrument used to diagnose certain diseases of the cornea and ocular surface. The cornea is the front anatomical structure of the eye and the first layer of the eye responsible for focusing light and vision. Some corneal diseases, such as keratoconus, pellucid marginal corneal degeneration, etc., are sometimes not easily detected by gross examination, but rather require topographical imaging, which scans and maps out the curvature of the cornea. This helps your optometrist confirm or rule out the diagnosis of these corneal conditions.

Once diagnosed with the appropriate corneal disease, your eye doctor can determine the ideal options to give you the best quality vision. With these certain conditions, the corneal surface is irregular. Thus, patients experience distortion, double vision, glare, haloes, and blur with soft contact lenses and glasses because light can no longer focus properly through the eye. Specialty contact lenses maintain their rigid shape as they curve over the cornea and ocular surface. Thus, the specialty contact lens resembles are regular, rounded surface to provide better optics and vision; they include rigid gas permeable contacts, hybrid contacts, and scleral contacts.

The most common corneal disease to be fit with specialty contact lenses is keratoconus. Keratoconus is a progressive disease of the cornea, where the cornea becomes thinner with time due to a weakening of collagen fibers. As keratoconus progresses, the cornea begins to bulge outward and takes on a more cone shape. The age of diagnosis can range from approximately 10-30 years old. In mild cases, soft contact lenses and glasses can still deliver good vision, but as the disease progresses, specialty contact lenses are the best option.

At Grand Vision Optometry, we offer multiple choices of specialty contact lenses to suit your unique corneal needs:

  • Rigid gas permeable contact lenses (RGPs) are small lenses that rest on the cornea. They provide clearer vision than glasses and soft contact lenses. Under certain circumstances, RGPs may move around or dislodge due to their size.
  • Hybrid contact lenses are a bit larger in diameter due to their design that rests on the cornea. They have a soft peripheral lens edge and rigid center to combine better vision and comfort to resemble the comfort of a soft contact lens and superior vision of an RGP.
  • Scleral contact lenses are another comfortable larger diameter contact lens that acts a prosthetic to completely arch over the cornea, which act to mimic a normal ocular surface especially for patients with advanced keratoconus. They are less likely to dislodge from the eye and have better stability.

-Dr. Iris Wong

How to clean your glasses


Tips to Keeping Your Lenses Clean:

  • Do not use alcohol or ammonia based products on your lenses, as these can damage the special coatings on your lens.
  • When cleaning your lenses use an anti-glare safe lens cleaner that is not alcohol based.
  • Paper towels, Kleenex, and your shirt should be avoided as the fibers can be abrasive which may scratch your lenses.
  • Use a clean micro fiber cloth to clean your lenses, as a dirty microfiber cloth can end up just spreading around the oils and dirt (your lenses will look foggy).
  • To clean your microfiber cloth you can hand wash it with some gentle soap or throw it in with your next load of laundry.
  • You should wash your lenses once a week by applying a small drop of mild dish soap to each lens while rinsing under warm water.
  • For daily cleaning, apply a small amount of lens cleaner on each side of both lenses, then use your clean microfiber cloth to wick away any dirt and oils.

UNDERSTANDING SPRINGTIME EYE ALLERGIES

It’s getting to be that time of year again – when most allergy sufferers find their seasonal allergies kicking into full swing. The reason why springtime allergies hit us so hard in San Diego is the timing of plant reproduction cycles – it’s when the most pollen is in the air. Wind pollinated trees (such as oak and pine) tend to release their pollens between February and May and wind pollinated grasses release their pollens between March and October. At the end of May, ragweed and other weed plants are active, producing copious amounts of pollen – keeping allergy sufferers in agony until the end of autumn. Because wind-pollinated species of plants produce the highest volume of pollen, April and May tend to be peak allergy months.

Eye allergies, also known as “allergic conjunctivitis,” tend to be chronic, and flare up during periods of heavy pollen, dust, and other allergen exposure. Common allergic conjunctivitis symptoms are: itchiness, watery eyes/tearing, redness, swelling of the eye tissues and eye area, and eye irritation. These symptoms can cause significant discomfort, blur vision, and cause problems with contact lens wear.

To minimize the impact of eye allergies:

  • Do not touch or rub the eyes.
  • Wash hands frequently with soap.
  • Wash bed linens/pillowcases in hot water.
  • Reduce contact lens wear time or consider switching to daily disposable contact lenses.
  • Wash hair at night to prevent pollen from lodging in your pillows/blankets (allergens can get trapped in hair during the day, causing morning symptoms).
  • See your eye doctor for prescription strength eye drops and other recommendations that can reduce (and sometimes prevent) the allergic response.

Grand Vision Optometry uses the most advanced technology to ensure superior vision health diagnostic and treatment excellence. Additionally, because we believe in compassionate eye care, we will take every measure to provide your vision and eye health care in a pleasant, soothing atmosphere.

-Dr. Mika Fu

PROTECTING YOUR EYES FROM UV/SOLAR RADIATION

As the weather warms up and we get closer to the start of summer, our families tend to spend more time outdoors and in the sun. While most of us are aware of the harm UV (solar) radiation can do to the skin, we may not realize that exposure to UV radiation from the sun can also harm the eyes and affect vision. Because the damage from UV radiation is cumulative, much of the sun/UV exposure during childhood and early adulthood can increase the risk for developing diseases and disorders later on in life.

There are three types of UV radiation: UV-A (long-wave), UV-B (short-wave), and UV-C. Most UV-C radiation is absorbed by the ozone layer in the upper atmosphere, and does not pose a significant threat to eye and skin health. However, both UV-A and UV-B radiation do penetrate the atmosphere and can play a role in the development of many health conditions such as:

  • Skin cancer (especially around the eyelids and lower eyelash line)
  • Eye cancer/melanoma of the eye
  • Cataracts (a cloudiness of the intraocular lens that causes blurry vision and glare)
  • Macular Degeneration (permanent loss/distortion of central vision)
  • Premature aging of the skin and the eye structures
  • Photokeratitis (“sunburn of the eye”)
  • Damage to the retina (the nerve layer of the eye that allows you to see)

To protect your eyes from solar radiation it is important to invest in a good quality pair of sunglasses. If you need to wear glasses for clear vision, sunglasses can be made with your prescription, or you can wear non-prescription sunglasses over contact lenses. (Ask your eye doctor for recommendations tailored to your specific vision needs.) Also, beware of poor quality sunglasses – the pupils of the eye increase in size behind dark tinted lenses and if the lenses are not properly filtering UV radiation, you have now created a larger “hole” for UV to get inside and damage the eye.

Features to look for in a quality pair of sunglasses:

  • 99% to 100% UV-A and UV-B blocking
  • Lenses should screen out 75 – 90% of visible light
  • Gray tinted lenses to reduce color distortion (maintain colors true to life) or
  • Brown/Amber tinted lenses to increase contrast (great for sports)
  • Polarized lenses to reduce glare/reflections
  • Properly fitting frame with few gaps around the tops and sides (so that there is little space for unfiltered stray light to reach the eye)
  • Polycarbonate or Trivex lens material (for impact protection) for sports or potentially eye-hazardous work
  • Ask your eye doctor for specific brand recommendations

In addition to wearing a good quality pair of sunglasses, wear a hat or cap with a wide brim whenever you spend time outdoors. Certain brands of contact lenses can also help to screen out some UV (but are not considered a substitute for sunglasses). Make sure to visit your eye doctor for yearly comprehensive eye exams to monitor eye health, maintain good vision, and keep track of your sun protection needs.

-Dr. Mika Fu

VISION BEYOND THE AGE OF 40

Around the age of 40, most people (even those with “perfect vision”) begin to experience problems focusing on near objects and fine print. These normal age-related changes, called presbyopia, are caused by a hardening and loss of flexibility of the intraocular lens (inside the eye). As these changes begin, reading and focusing become harder causing eyestrain, blurry vision, and headaches.

Reading glasses and Bifocal glasses can help with these changes – but most people have trouble multi-tasking with these types of glasses. Reading glasses only work for a short range of close distances, and Bifocals do not provide any intermediate vision (the area between 24 inches and 10ft) – and have visible lines etched into the lenses. As the world has become more technology-focused, Progressive glasses have replaced these other types of glasses as the best option for meeting every day vision needs, as they allow multi-tasking at all ranges – and are more attractive cosmetically (no lines).

In a Progressive lens, the distance prescription is set in the top “straight ahead” position (perfect for tasks such as driving or watching TV). As your eyes travel downward in the lens, the prescription changes gradually in a gradient fashion, allowing you to focus on closer and closer objects (such as the computer screen or dashboard of your car). The bottom portion of the lens gives the strongest “reading” prescription, giving clear vision for close objects and fine print. There are no “lines” or harsh transition zones in a Progressive lens – the lenses are smooth and clear, and look like a regular pair of glasses.

Benefits of Progressive glasses over bifocals or reading glasses:

  • Vision for all distances (near, far, and in between)
  • Ability to multi-task without removing glasses or switching pairs
  • No “lines” etched into the lenses (lenses are smooth and clear)
  • Smooth transitions for the eye between different distances (no harsh “jumps” in vision)

However, not all Progressives are created equal. Older style progressives utilize a “hard” design that gives a very narrow intermediate and reading corridor. These older progressives are pre-made, in a “one size fits all” approach. Many people have a hard time adjusting to these older lenses due to the very narrow reading areas, and enormous amounts of side distortion. In contrast, the newer styles of Progressive lenses are “freeform” and “digital” – they have a much wider reading and intermediate area, and a lot less side distortion than the older style Progressives. These modern Progressives are custom lenses designed specifically for your measurements, your prescription, and the frame that you have chosen. “One size fits all” may be adequate for a t-shirt, but it is not the best approach when it comes to something as important as your vision.

In my office, we offer the latest in technology – digitally surfaced, freeform, custom Progressive lenses. Each pair is custom-made to a patient’s own measurements and prescription, and takes into account the width and depth of the frame selected. My staff of American Board of Opticianry certified opticians have the up-to-date skills and knowledge to correctly fit and measure these lenses that I prescribe for my patients. We are currently accepting new patients, and would be happy to discuss these types of lenses with you – please stop by or call for an appointment!

-Dr. Mika Fu