Today, corneal inlays offer an alternative to wearing reading glasses. They are implanted in the eye with a minimally-invasive surgical procedure, restoring close-up vision. Your ophthalmologist will help you determine whether you are a candidate for a corneal inlay and which type may be your best fit.
As you enter your 40s and 50s, chances are that you will have a little more difficulty reading a book or seeing your phone’s screen up close. This is a symptom of a common, age-related eye condition called presbyopia. Presbyopia is caused by a stiffening of the eye's lens, which gradually weakens the ability to focus on near objects. Until recently, the most common treatment options for presbyopia were eyeglasses, contact lenses or laser vision correction surgery.
What Are Corneal Inlays?
A corneal inlay is a tiny device, smaller than the width of an eraser tip. During a 10-15 minute surgery, a laser is used to cut a small pocket or flap in the middle of the non-dominant eye’s cornea. The inlay is then inserted into or under this pocket or flap, depending on which inlay is used. The implant corrects close-up vision by increasing the depth of focus of the center of the cornea.
There are three main types of corneal inlays, which look and work a little differently. Two of them are now FDA-approved for use in the United States.
Refractive Corneal Inlays
The design of refractive corneal inlays is similar to a multifocal contact lens or intraocular lens, with different areas of the inlay giving different levels of magnifying power. This allows the eye to focus up close and far away. This type of inlay is currently under review by the FDA.
Small Aperture Inlays
Small aperture inlays work like the aperture of a camera, changing how much light enters the eye. This device is a donut-shaped ring with a pinhole opening in its center. The pinhole focuses light very specifically into the eye, narrowing the field of vision. This provides better sight at close range. The KAMRA is the first small aperture inlay approved by the FDA (in April 2015) for use in the United States.
Corneal Reshaping Inlays
Corneal reshaping inlays change the shape of the cornea itself to improve vision. The implant is a small, clear disk made mostly of water, inserted closer to the front of the cornea than other types of inlays. When implanted, the reshaping inlay makes the center of the cornea steeper. Light rays that travel through the thinner portion of the inlay allow distant objects to be seen clearly, while near objects can be seen clearly through the central, curved part of the cornea. The FDA approved the Raindrop, the first inlay in this category, in June 2016.
The American Academy of Ophthalmology says, “The Raindrop inlay is the first FDA-approved implantable device that changes the shape of the cornea to achieve improved vision. Corneal inlays are an interesting development in ophthalmology. They may be an attractive option for people who dislike wearing reading glasses enough to invest in a surgical alternative. However, corneal inlays are very new. And, as with any new technology it needs to be evaluated over time for long-term safety and efficacy.”
After surgery, patients should expect to use antibiotic and steroid eye drops for up to a month. Risks associated with corneal inlays include problems with glare, halos and difficulty seeing at night or reading in dim light. Other potential complications include corneal scarring, swelling, inflammation, thinning of the cornea, clouding of the cornea. The corneal inlay procedure is reversible, as the devices can be removed from the eye.