Glasses with anti-reflective coating have grown in popularity as more jobs demand that employees spend time behind a computer. Everyday use of smartphones, TV viewing, and other gadgets with screens can strain the eyes even further.
In the past, AR coating was a nuisance because it would easily peel off, scratch, and get dirty easily. Today’s AR-coated lenses have improved. Their anti-reflective capabilities are “seared” into the lens.
Block blue light, which can help with eye strain, blurry vision, and dry eyes.
Resist smudges and scratches.
Stop water damage.
Brands such as Crizal are major purveyors of these lenses. They specialize in lenses for children and have a variety of lenses with these features. Some of their offerings are expensive.
In addition to helping you see better, AR-coated glasses are more aesthetically pleasing if you are a person who is often photographed. They let light enter more easily, allowing people to see your eyes better beneath your lenses.
A primer on the use of these therapeutic lenses to serve and protect the corneas of our patients.
By Susan Gromacki, O.D., M.S., F.A.A.O.
The concept of a protective eye bandage originated in the first century A.D., when Celsus reportedly applied a honey-soaked linen to the site of a pterygium removal to prevent symblepharon development.1,2 Bandage soft contact lenses were first used in the 1970s following the development of hydroxyethyl methacrylate (HEMA) by Otto Wichterle.2 With the recent advances in material technology, today’s bandage contact lenses provide the same benefits as their predecessors—but with enhanced convenience, improved healing and increased corneal health.
Bandage Lens Basics By definition, a bandage contact lens protects the cornea. Many different lens types can be utilized to accomplish this goal (see tables 1 and 2); however, because of their high oxygen permeability and FDA approval for extended wear, silicone hydrogel soft contact lenses are currently most practitioners’ first choice.
Bandage lenses protect the cornea not only from potential exterior sources of injury, but also from a patient’s own eyelids. The shearing effect created by the lids during the blink can inhibit re-epithelialization and cause pain. Use of a bandage lens facilitates corneal healing in a pain-free environment.
Depending on the patient’s ocular condition, he or she may wear their therapeutic lenses for a period of days to years. They may be utilized for daily or extended wear (see table 2). Because there is generally an underlying disease process precipitating the need for a therapeutic lens, extra caution must be taken to clean and disinfect the lens after wear, keeping in mind that silicone hydrogel lenses tend to deposit lipids more readily than HEMA lenses (see image 1). That said, the addition of a digital rubbing step is necessary for lenses that are used more than once.
It is critical to perform frequent follow-ups for bandage contact lens patients. One reason is that a bandage lens fit, by design, demonstrates less movement than a traditional soft lens fit. The theory is to provide increased patient comfort while preventing the healing epithelial cells from sloughing off due to any mechanical trauma of the lens itself.3 In addition, it is important for the practitioner to be vigilant regarding the detection of signs of microbial keratitis. The compromised cornea—especially when wearing lenses in an extended wear modality—is at particular risk for infection.4
Indications Bandage contact lenses are indicated for many different reasons, including: protecting the eyes, increasing comfort, facilitating healing and sealing wound leaks. We’ll explore these indications, and others, in more detail in the following paragraphs.
• Protection. Corneal protection is needed in the case of several conditions, including: entropion, trichiasis, tarsal scars, recurrent corneal erosion, post-surgical ptosis and surgical sutures or exposed suture knots.
Recurrent erosions are a typical sequella of epithelial basement membrane (basal lamina) trauma or are secondary to anterior basement membrane dystrophy, anterior basement membrane degeneration or stromal dystrophy. A bandage contact lens is the second line of treatment, after hyperosmotic drops and/or ointment fail.2,5 An added benefit is the enhanced vision provided by the smooth refracting surface of the contact lens, as opposed to an irregular anterior corneal surface.5 Hypertonic saline drops should continue to be utilized concurrently with the lenses.
• Pain relief. The mitigation of corneal pain is another important indication for therapeutic contact lenses. The conditions most in need of this therapy include bullous keratopathy; epithelial erosion and abrasion; filamentary keratitis; and postoperative penetrating keratoplasty.
In bullous keratopathy, endothelial failure results in corneal edema, which in turn creates epithelial blisters that rupture, causing pain, foreign body sensation, and photophobia. A bandage contact lens reinforces the damaged tissues and protects the nerve endings from the abrasive actions of the eyelids. Patients who are awaiting a conjunctival flap or cornea transplant may be fitted with therapeutic lenses for up to 30 days at a time.2 Until recently, pressure patching was the standard of care for treating large epithelial abrasions (see figure 2). With this treatment, the caveat was to refrain from patching contact lens wearers or injuries caused by presumed vegetative matter or false fingernails. The utilization of a bandage contact lens provides protection and healing for all three of these conditions, and it has now supplanted patching as the standard of care. The authors of the Wills Eye Manual caution, however, that prophylactic topical antibiotics should be used concurrently and that daily follow-up care is mandatory.6
1. Therapeutic soft contact lens with 2+ surface coating.
The other advantage of bandage contact lenses over patching is the ability to continue to install topical ophthalmic medications. This is particularly important after a corneal abrasion, erosion, or corneal refractive surgery, which necessitate the frequent installation of antibiotics and/or artificial tears. Some reports caution against the installation of cycloplegic agents (which reduce the pain associated with a corneal abrasion/erosion or after corneal refractive surgery) in bandage CL wearers. The dilating drops can cause the bandage lenses to dry out and become less comfortable, especially overnight, with the end result a potentially decreased healing response.7 On the other hand, bandage contact lenses can be utilized—by design—as vehicles for drug delivery, but the exact way to ensure a consistent dosage is still under investigation.
• Healing. The use of bandage contact lenses to facilitate healing is particularly necessary for the following conditions: chronic epithelial defects, corneal ulcer, neurotrophic keratitis, neuroparalytic keratitis, chemical burns and basement membrane disease.
They also enhance healing following corneal surgery, particularly refractive surgery. They protect the cornea from exposure or from the irritation caused by rubbing the eye as the corneal wounds are healing. Therapeutic bandage contact lenses are a mainstay after photorefractive keratectomy (PRK) procedures, in which the removal of the epithelium leaves an open wound that takes about one week to heal (see figure 3). They are also valuable for the following procedures: laser-assisted in situ keratomileusis (LASIK), laser-assisted subepithelial keratomileusis (LASEK), Epi-LASIK, penetrating keratoplasty (PK) and phototherapeutic keratectomy (PTK), lamellar grafts and corneal flaps.
2. The use of therapeutic contact lenses has replaced pressure patching as the standard of care for epithelial abrasions such as the one in the image above.
• Sealing. The lenses also may aid in sealing leaky wounds. Serving as a splint or sealant, the lenses can be beneficial after cataract, penetrating keratoplasty or glaucoma filtering surgery.
• Maintenance of corneal hydration. The role of bandage contact lenses in dry eye is controversial. For patients who need to continually instill lubricating drops into their eyes, particularly after refractive surgery, the benefits of using a bandage lens can be great. Other patients who benefit are those who have significant lagophthalmos and subsequent corneal exposure. However, contact lenses are generally contraindicated for dry eye.7
• Structural stability and protection in piggyback lens fitting. Many patients benefit from the utilization of a soft and rigid lens concurrently. The rigid lens provides crisp vision, particularly for irregular corneas, and the soft bandage lens protects the cornea, preventing irritation and abrasions. Examples include elevation differences in the host/graft junction, keratoconus and in the presence of scar tissue.
Contraindications
3. The cornea, one day following PRK.
Each clinician must assess his patient’s condition carefully to determine whether a bandage contact lens is warranted. Interestingly, many of the conditions that require bandage contact lenses (dry eye, infection, inflammation, etc.) contraindicate lens wear in general. In addition, therapeutic contact lenses should not be used in patients who are unwilling or unable to comply with the necessary treatment and follow-up.
Dr. Gromacki is a diplomate in the Cornea, Contact Lens and Refractive Technologies Section of the American Academy of Optometry. She is Chief Research Optometrist at Keller Army Community Hospital, West Point, New York.
1. Arrington GE. A history of ophthalmology. MD Publishers, New York, New York, 1959. 2. Weiner BM. Therapeutic bandage lenses. In: Silbert JA, ed. Anterior Segment Complications of Contact Lens Wear. Churchill Livingstone, New York, New York, 1994; 455-471. 3. Aquavella JV. Chronic corneal edema. Am J Ophthalmol 1973;(76):201-207. 4. Thoft RA, Mobilia EF. Complications with therapeutic extended wear soft contact lenses. Int Ophthalmol Clin. 1981;(21):197. 5. Chan WE, Weissman BA. Therapeutic contact lenses. In: Bennett ES, Weismann BA, (eds). Clinical Contact Lens Practice, Lippincott Williams & Wilkins: New York, New York, 2005: 619-628. 6. Ehlers JP and Shah CP, eds. The Wills Eye Manual Fifth Edition, Wolters Kluwer Health, New York, New York, 2008:15-16. 7. Russell GE. Bandage lenses: new opportunities in practice. Contact Lens Spectrum. 2004(6). 8. Tyler Thompson TT. Tyler’s Quarterly 2011;28(3):32-52. 9. White P. 2011 Contact Lenses and Solutions Summary. In: Contact Lens Spectrum (suppl) 2011;27(7):14.
You can buy 3 in 1 smart infrared thermometers at Eyeupdate clinic & optical supplies located at 01 Ajuwon junction, Ajuwon bus stop, beside BNPL filling station, Ajuwon near the grailand estate gate.
This is a non contact thermometer which can be used to take temperature measurement of the human body near the forehead, ear or wrist. Other features of the thermometer are:
Fast measurement (1 second)
Fever warning
Measurement range: 32. 0°C – 42. 2°C
Memory recall: 32 readings
Automatic shutdown: 60s
Error Resolution: 0.1°C
Can measure body temperature on human forehead
Can measure body temperature on the wrist
Can measure human temperature on the ear
Manufacturers: Alicn Medical Inc
Price: N35, 000
Tel: 08107531046
Address : Eyeupdate clinic & optical supplies,
01, Ajuwon junction, Ajuwon bus stop, off Elliott bus stop, Iju-Ishagah (beside BPNL Filling station, Ajuwon)
Buy infrared thermometer in Alagbole Akute Ajuwon Matogun
It is possible to do some basic testing of your vision and the vision of your family members and friends at home. Home eye testing is not a substitute for a complete medical eye examination by an ophthalmologist. Testing your vision at home will not be as accurate as what your ophthalmologist can do. But home eye testing could help you discover a problem that requires professional attention.
Children under age 3 should have their vision tested by an optometrist, ophthalmologist or other vision care professional.
What You Need to Test Your Vision at Home
Something to cover the eye, like a paper cup or facial tissue.
Scissors.
Tape or tack to hang the test chart on the wall.
A pencil or pen to record the results.
A yardstick, tape measure, or ruler.
A flashlight, if available.
A well-lighted room at least 10 feet long.
The correct testing chart.
Prepare the Test Area
Select either the child’s or adult’s test chart and print it out.
When printed, the largest letter at the top of the chart should be just under an inch (23 millimeters) tall.
Measure 10 feet from a wall with no windows, and place a chair at this point.
Tape or pin the chart on the bare wall, level with the eyes of the person you will test as he or she sits in the chair.
Testing a Child (Age 3 or Older)
Explain to your child that you are going to play a “pointing game.” Using the practice E card, show him or her how to point in the same direction that the E is “pointing.” Turn the practice E in the four different directions (up, down, right, left). You may hold the practice card as close as the child wants until he or she can point in the four directions without help.
Have your child sit in the chair 10 feet from the chart, holding the cover over one eye without applying any pressure. Do not let the child peek. A second person may be needed to hold the cover in place and watch for peeking. If your child wears glasses, he or she should wear them during the test.
If the chart seems too dark to see clearly, use the flashlight to illuminate the test letters.
Point at each of the Es, starting with the largest. Have your child point in the direction the E is pointing.
Write down the number of the smallest line your child can correctly see (more than half of the Es correctly identified).
Then repeat the test with the other eye covered. If your child is tired, you may wish to test the other eye at a different time.
Testing an Adult or Older Child
Have the person being tested sit in the chair, 10 feet from the chart. Make sure the chart is level with his or her eyes.
Have the person being tested cover one eye. If he or she uses eyeglasses for distance vision, the glasses should be worn during the test.
Shine the flashlight on each line of the chart, while the person you are testing reads the letters out loud. Continue to the bottom row or until the letters are too difficult for the person to see.
Write down the number of the smallest line seen correctly (the line with more than half of the letters correctly identified).
Now repeat the test with the other eye covered and record the results.
What Are Normal Scores for Home Eye Testing?
A child should be able to see the 20/40 line by age 3 or 4 and the 20/30 line by age 5. If you test your child several times on different days and your child cannot see the expected line of print or cannot see the same line with each eye, he or she may have an eye problem. You should have your child evaluated by a physician.
An older child or adult should be reading the 20/20 line. You should arrange for a medical eye examination by an ophthalmologist if there are abnormal results.
Home Vision Test Results
Record the results of your home screening by filling in the number of the smallest line the person could read for each line below. If the test results indicate that you or your child needs to see an ophthalmologist, take the numbers you wrote down with you.
