What You Need To
Know About Extended
all the benefits and risks of these popular contact lenses.
MICHAEL J. LIPSON, O.D., F.A.A.O., Livonia, Mich.
wear (EW) contact lenses are here to stay! The newest of the EW lenses are highly
oxygen-permeable and much safer than their predecessors, but it still pays to proceed
Currently, there are a number of lenses with FDA approval
for between six and 30 days of extended or continuous wear. They are generally categorized
as soft-hydrogel, silicone-hydrogel and gas-permeable. With a large range of parameters
available, and more becoming available every month, extended wear is a viable option
for you and your patients.
Why fit extended wear?
First, patients like it! They enjoy the convenience of spending
less time on care and handling, along with the pleasure of waking-up to a clearer
world. Patients who experience chronic redness from solution reactions or lens deposits
may experience fewer red-eye reactions. Others, who frequently damage their lenses
during handling, may gain better comfort and longer-lasting lenses. It can also
reduce the risk in situations when it may be difficult to handle lenses, like while
camping or using public restrooms.
Second, doctors like it! Many of those who are fitting extended
wear find they have fewer CL dropouts, less complications and increased patient
loyalty. When patients have fewer problems, they continue to wear these lenses and
return to the doctor who prescribed them. They also talk to others about these contact
lenses that give them clear, comfortable vision.
Not everyone is a candidate for this modality, however. Patients
who will likely do well with extended wear are those have a history of compliance
and healthy corneas. Patients with chronic allergies, significant dry eye, corneal
dystrophy, any corneal pathology (like keratoconus) and some diabetics (due to increased
healing time) are generally not good candidates for this wearing schedule.
Patients who upgrade from other lenses to extended wear may show
slight Rx changes after the first few weeks of wear. Advise them of this possibility
beforehand and schedule follow-up visits sooner than you would for new wearers to
monitor for these refractive changes. Having patients discontinue their current
lenses for a few days prior to commencing extended wear can also be helpful.
Proceed with caution
Even though some high-Dk lenses are approved for up to 30 days
of continuous wear, you, as the prescribing doctor, must determine each patient's
wearing schedule individually. Prescribe with safety as your top priority, convenience
second. Even with plenty of oxygen transmission, careful follow-up is necessary
to assess proper lens fit and movement, the presence of any debris/deposits on or
under the lens, keratitis (mechanical or microbial) and possible eyelid reactions.
Any patient wearing a lens while sleeping has the potential to get debris trapped
between the eye and the lens. Based on observations of the lens and the cornea during
initial follow-up visits, establish a safe wear schedule for each patient. According
to one study, the incidence of microbial keratitis with extended wear of soft hydrogel
lenses was estimated to be one in 500 (a 2004 study estimates about one in 200).
Similar studies have projected the incidence of microbial keratitis with
extended wear at one in 5000, and with extended wear GP, one in 10,000.
Conduct fitting evaluations at three to four days after the initial
fit and again two to three weeks later. Strongly advise patients to report any discomfort,
blurred vision or redness immediately for evaluation. Regular follow-up care is
just as essential as the wearing/replacement schedule. In our office, we schedule
annual exams with a contact lens evaluation every six months after the initial fitting
visits. I also advise having a strategy for in-office and specialty referral management
of potentially serious complications.
Many patients will wear lenses for the prescribed time period
and dispose of the lenses upon removal. Obviously, these patients will not require
solutions or a care system for disinfection. For those who do re-use lenses, proper
disinfection is crucial. In these cases, stress the importance of hand washing,
lid hygiene and exact following of disinfection procedures. Multi-purpose and hydrogen
peroxide systems have been found very effective. Re-using a contaminated lens significantly
increases the risk of infection with overnight wear. However, gas permeable lenses
may periodically need special cleaning or polishing and require regular replacement.
One activity that poses a risk for extended wearers is swimming.
A recent study at Pacific University showed water-born bacteria binds to the surface
of all soft lenses. The researchers concluded that if patients wear lenses while
swimming, they should remove lenses after swimming for a thorough cleaning and disinfection
prior to overnight wear. They also advised that patients wear tight-fitting goggles
Extended wear gained FDA-approval because it satisfied requirements
for oxygen transmission and safety. You are obligated to ensure that each patient
is monitored for continuing eye health and as such, must establish a safe wearing
schedule for each patient. Once that schedule has been determined, it is imperative
that the patient follow it. Hand the patient (or parents if the patient is a minor)
a written wearing/disposal schedule and keep a copy in the patient's record. I also
include the date and time of their next follow-up appointment written on this sheet.
When dispensing lenses, it is important to stress that the next complete vision
and contact lens evaluation will be necessary when the prescription for theses lenses
Another tool to help with compliance is an "informed consent form."
This is an in-office document explaining what the lenses do, the benefits and risks
associated with extended wear, alternative modes of vision correction and the importance
of following your recommended wearing, replacement and follow-up schedule. This
form should also include emergency contact information of the doctor and office
so patients can contact the ECP any time a problem may arise. Have each patient
or guardian read and sign the form and include it in their file. Also give a copy
to the patient to keep in their records.
The professional expertise involved and the additional time requirements
demand that you establish higher professional fitting fees for management of EW.
Explain this to patients going into extended wear. Those who want the convenience
will appreciate that you are providing a service that they may not have experienced
Prescribing extended wear lets your patients know you are working
with the latest contact lens technology. It also allows you to market yourself to
a new group of potential patients. This creates excitement for patients, while generating
referrals and revenue for the practice. As a final reminder, prescribe a safe wearing
schedule and monitor with careful follow-up to assure compliance.
Getting the Most
from Extended Wear GPs
Robert M. Grohe, O.D.
aphakic patients were among the first contact lens wearers in EW until intraocular
lens [IOL] implants gradually replaced the use of PMMA as an extended wear material.
Today, modern orthokeratology has expanded the role of GP contact lenses from premium
refractive correction among some cosmetic lens wearers, to slowing myopia progression
and often reducing/eliminating myopia with corneal refractive therapy.
Here are some benefits for patients
and eyecare practitioners when comparing soft with GP contact lenses for extended
Hyper-Dk lens materials promote
a safer extended wear experience by providing an oxygen-dense environment for the
cornea. Recent studies indicate less bacteria bind to the surface of hyper Dk GP
2. There is a lower incidence of corneal
ulcers and infiltrative keratitis in GPs when compared with soft-lens extended wear,
especially for non-silicone based hydrogel designs.
3. Dynamic tear exchange fosters a
better back-lens and surface/cornea (retro-lens) environment.
4. Using therapeutic agents to treat
chronic diseases such as ocular allergies or glaucoma is extremely easy.
5. Because non-damaging fluorescein
is used in evaluating corneal response to extended wear, the safety of the physiologic
assessment is improved.
6. GP laboratories have passed high
quality inspection standards, while implementing advanced manufacturing techniques
that enable better physical durability of lens materials.
7. Multiple lens parameters are available
to be customized and/or produced in-house. Contact Lens Manufacturing Association
(CLMA)-member laboratory consultants can also help with designs. And, fitting resources
are also available through the GP Lens Institute (GPLI) at: www.gpli.info.
8. Vision is clear, consistent and
precise, even with prolonged GP extended wear.
9. GP lenses have a longer life with
one-pair convenience. GP lens materials are able to withstand one to two years of
routine lens wear and handling.
10. With the addition of deposit-resistant
fluorine to recent GP polymers, they now require less cleaning, as the surfaces
remain more resistant to long-term deposit buildup.
Dr. Grohe is in private practice in Homewood, Ill. and Northwestern
University Medical School, Ophthalmology Department in Chicago and serves on the
Gas Permeable Lens Institute's Advisory Committee.
Care for GP Lenses
Robert M. Grohe, O.D.
when using GPs for extended wear generally include monitoring for
excessive corneal flattening, lens adhesion, corneal warpage and hyper-DK mishandling.
Using corneal topography to monitor for subtle, localized corneal distortion
or warpage can reduce the risk for complication. At each contact lens office visit,
watch for any emerging signs of lens adhesion or decentration, which would indicate
the need to refit due to a probable change in lens- and or corneal-curvature.
Complications can be dramatically
reduced when patients comply with regular follow-up care. Maintaining a safe patient
wearing experience typically calls for seven to 30 days of maximum lens wearing
at one time. In between visits, instruct patients to use a conditioning and cleaning
solution, along with overnight enzyme soaking prior to reinsertion in the morning.
Educate the patient about lens cleaning and handling techniques for hyper-Dk GPs
in the evening using the palm of the hand with the fifth finger in a back and forth
Since computer users are at greater
risk for dryness and redness, advise that they break the gaze cycle by looking away
from the monitor every 15-30 minutes and try to consciously blink 15-20 times per
minute when staring at the monitor. Some occupational concerns will preclude patients
for GP wear, including those exposed to high levels of dust, chemicals, organic
solvents or construction work.
Lipson is a clinical instructor
with the Department of Ophthalmology and Visual Sciences, Medical School,
Kellogg Eye Center at the University of Michigan. His clinical practice focuses
on primary care and specializes in contact lenses.
Optometric Management, Issue: August 2005