Refractive Surgery

Overview

Refractive surgery is a category of vision correction treatments designed to improve the refractive state of the eye by reshaping the cornea or altering the way the eye focuses light internally. Nearsightedness, farsightedness, presbyopia and astigmatism prevent the eye from properly focusing light, which in turn causes blurred vision. Refractive surgery reduces or eliminates these conditions, lessening dependence on contact lenses or eyeglasses. [adsense_160x600]

Refractive surgery candidates must be 18 or older and be in overall good health. Most patients undergoing refractive eye surgery have mild-to-moderate vision problems and are in their 30s or 40s. However, the procedure can be performed on adults of any age.
Candidates must have a contact lens or eyeglass prescription that has been stable for at least a year before seeking surgical treatment. Certain health issues, such as autoimmune conditions, may affect candidacy for certain surgical treatments.

Types of Refractive Procedures

Most refractive surgeries take just an hour or two to perform and incorporate the use of anesthetic eye drops rather than full anesthesia. There are a number of different refractive surgery methods, each differing in the exact way the eye is reshaped during the procedure. Common refractive surgery procedures include LASIK, PRK, LASEK, Epi-LASEK, INTACS, phakic IOLs and refractive IOLs.

LASIK Eye Surgery

LASIK, or “laser-assisted in situ keratomileusis,” is one of the most popular types of refractive surgery. It can correct common vision problems such as nearsightedness, farsightedness and astigmatism by altering the way light is bent (refracted) by the eye.

People who wear glasses or contact lenses, whose prescription has not changed over the last two years, may be good candidates for LASIK. However, large pupils, thin corneas or corneal surface irregularities may rule out LASIK as a treatment option.

LASIK is an outpatient procedure performed in a single session, requiring an hour or less for each eye. Anesthetic eye drops are administered before treatment begins to numb the eye, minimizing patient discomfort. A circular, epithelial flap is then cut in the corner of eye using a microkeratome or femtosecond laser. This enables the surgeon to access the underlying cornea, which is then gently reshaped with an excimer laser. To complete the procedure, the epithelial flap is folded closed.

LASIK is a commonly performed, safe procedure with a very low rate of complication. The procedure may result in halos around lights, light sensitivity dry eyes and glare. However, these effects should subside within six months of the procedure as eyesight stabilizes. The biggest risk is that eyesight will not improve as much as the patient had hoped. There is no guarantee of perfect vision following LASIK surgery, or that recipients won’t still need glasses. The degree of vision improvement varies from patient to patient.
LASIK does not require stitches and most patients are able to resume their normal daily activities in just a day or two. During this time, it is important to avoid irritating the eye or straining vision.

The cost of LASIK eye surgery varies, but is usually between $1,000 and $5,000. Typically considered an elective procedure, LASIK costs are not usually covered by health insurance. Financing options are typically available for those who cannot afford the out-of-pocket expense of LASIK.

PRK Eye Surgery

PRK surgery, also known as photorefractive keratectomy, is another refractive surgery treatment used to correct farsightedness, nearsightedness and astigmatism. A benefit of PRK is that candidacy is broader than other treatments such as LASIK. Patients with thin corneas, large pupils or corneal surface irregularities who are unable to have LASIK make for good PRK candidates.

PRK involves the precise removal of a thin layer of targeted cells from the surface of the eye using a specialized alcohol solution in conjunction with a blunt surgical tool. This allows for more precise control over the area of tissue being removed. Once the epithelium has been removed (it grows back in a matter of days), an excimer laser is used to shape the underlying eye. Anesthetic eye drops are administered to minimize any discomfort associated with the one-to-two hour outpatient procedure.

As with LASIK, vision-related side effects of PRK may include vision distortion, glare and halos. However, the rate of complications is believed to be lower than that associated with LASIK. These risks may be further reduced through proper screening to ensure this procedure is the right choice.

Due to the removal of the outermost layer of the cornea, PRK has a slightly longer recovery period. Vision should improve gradually over a few weeks following the surgery, though it is not uncommon for vision improvement to be realized sooner. Patients can return home immediately following the procedure, but are advised not to drive due to the likelihood of blurred vision. Strenuous activities should be avoided – particularly those likely to strain or irritate the eyes – for at least a week to give the eyes time to heal.

The cost of PRK fluctuates depending on patients’ unique circumstances, but is usually between $1,500 and $3,000 per eye. Like LASIK, PRK is considered an elective procedure and therefore not generally covered by health insurance.

LASEK Eye Surgery

LASEK eye surgery, or Laser Epithelial Keratomilieusis, is one of the newer types of refractive surgery available for people who are nearsighted, farsighted or who have astigmatism. Like PRK, LASEK is typically recommended for patients whose cornea is too thin or whose pupils are too large for other forms of laser eye surgery such as LASIK.

LASEK is performed in a single outpatient session, requiring just an hour or two to perform.

The main difference between LASEK and other forms of laser eye surgery is the method used by the surgeon to gain access to the underlying tissue of the cornea. The outer layer of the cornea remains intact; however, a microscopic surgical flap is made to separate the epithelium from the stromal layer (it is not completely removed). A laser is then used to reshape the underlying corneal tissue, improving the patient’s vision. Once this process is completed, the surgeon places the epithelial flap back over the eye, allowing it to adhere naturally without stitches.

The rate of complications with LASEK is lower than that associated with other vision correction surgeries. However, potential complications are the same and include blurred vision, glare, poor night vision and halos. LASEK side effects typically resolve themselves within several months of the surgery. Although in very rare cases, some of these side effects may be permanent.

LASEK recovery time is lower than that of other forms of laser eye surgery due to the fact that the outer surface of the eye remains intact. Most patients take a few days away from work and other activities. Many patients notice an immediate improvement in their vision, while others notice vision improvement gradually over several weeks. During this time, it is important not to do anything that would strain or irritate the eyes.

The cost of LASEK eye surgery ranges from $1,500 to $3,000 per eye. Like LASIK and PRK, LASEK is considered an elective procedure and therefore not covered by most health insurance policies.

Epi-LASIK Eye Surgery

Epi-LASIK is a more recently developed refractive surgery option conceived as an alternative to LASIK. Introduced in 2003, Epi-LASIK is a good option for patients with an irregular cornea or suffering from chronic dry eyes. Because of the way the epithelial flap is created, it is an ideal treatment option for people with flatter corneas and mild vision problems.

Anesthetic eye drops are applied prior to treatment to numb the eyes and minimize discomfort. An epi-keratome or epithelial separator is then used on the surface of the cornea, gently separating the epithelial layer. Gentle suction creates a hinged portion of epithelial tissue that is then lifted out of the way, exposing the underlying tissue for laser reshaping. The laser ablates (removes) targeted corneal cells, correcting the patient’s vision.

Once the procedure is completed, the epithelial sheet is repositioned over the eye where it adheres without requiring stitches. A special contact lens is then placed on the eye keeping the flap in place while it heals.

Compared to other refractive surgery procedures, Epi-LASIK causes less damage to the corneal nerves, making it one of the safest forms of refractive surgery. Complications are therefore uncommon, but can include over or under-correction of vision, halos, glare and other vision issues. Some patients also may experience delayed epithelial healing or loss of the epithelial flap created during the surgery.

Epi-LASIK patients are advised to avoid driving for a week following the surgery. Taking a week off of work and avoiding normal daily routine is also recommended for most patients. During this time, it is important not to do anything that would strain or irritate the eyes. Antibiotic eye drops are provided after the surgery in order to promote healing and reduce the risk of infection. The post-operative contact lens may be removed a few days after surgery. Many patients notice immediate improvements in their vision while others find that their vision improves gradually over several weeks or months.

The cost of Epi-LASIK surgery ranges from $1,500 to $3,000 per eye. Like the aforementioned refractive surgery options, Epi-LASIK is considered an elective procedure and therefore not generally covered by health insurance.

Corneal Ring Segments (INTACS)

Intrastromal corneal ring segments, also known as intracorneal rings or INTACS, are small devices implanted into the eye to correct vision. This minimally invasive refractive surgery option is often used to correct mild-to-moderate nearsightedness (3.0 diopters of myopia) or keratoconus, an eye disorder in which the cornea takes on a more conical shape than the normal gradual curve.

In general, INTACS patients are adults aged 21 or older, in good overall health with a stable eyeglass prescription of at least a year. Some patients opt for INTACS because the implants are removable, allowing for reversal of the correction or replacement with a different implant to change the degree of correction. This sort of flexibility is not available for all refractive surgery options.

The outpatient INTACS procedure requires less than an hour to perform. Anesthetic eye drops are used to minimize any discomfort during implantation.
A small incision is made in the cornea, into which the INTACS are implanted in the eye. The eye surgeon inserts two semi-circular or crescent-shaped rings between the layers of the cornea, one on each side of the pupil. It is not uncommon to feel a little pressure while this is being done. Corneal rings are made of PMMA (an acrylic glass) and have the effect of making the cornea flatter, thereby changing the way that light is refracted as it passes through the cornea. Different thicknesses are available, which in turn controls the amount of corneal flattening. The corneal rings cannot be felt once inserted, but the eyes will need some time to heal before vision improvement may be experienced.

Unlike with laser refractive surgery, no tissue is removed for INTACS placement. Once the INTACS are in place, the incision closes itself without the need for sutures. Patients are free to return home immediately after the procedure is completed, though driving is not suggested.

INTACS pose few complications and risks. Vision distortion, problems with night vision and infection may result in rare cases. Approximately 4% of patients experience visual disturbances or are not satisfied with the results. Fortunately, such situations are correctible through INTACS removal. Vision can then be restored to how it was prior to surgery.

After surgery, it is recommended that patients plan to take a few days away from work. Most patients are able to return to their normal activity level within a day or two. INTACS boast a greater vision correction success rate when compared with LASIK and other types of refractive surgery. Many patients find that they are able to achieve 20/20 vision or better after the procedure.

The cost of INTACS varies from surgeon to surgeon, but is usually between $2,000 and $7,000. Costs include the corneal rings themselves, the surgeon’s fee, the facility and equipment fees, and any pre- or postoperative care, such as medicated eye drops.

Phakic IOLs

Phakic IOLs (intraocular lenses) are surgically implanted lenses offering long-term correction of common vision issues such as nearsightedness.
Marketed under brand names such as Visian and Verisyse, phakic IOLs are implanted in one of two ways: either behind the iris (the colored portion of the eye) or between the cornea and the iris. Once implanted, the artificial lens alters the way the cornea refracts light, achieving sharper focus and superior vision.

Implantable lenses such as phakic IOLs are typically considered when other refractive surgery treatments are not an option. For example, thin corneas or a severe degree of myopia (between -3.00 and -20.00 diopters) may make a patient a better candidate for a phakic IOL.

Two types of phakic IOL have been approved by the FDA for use in the United States: Verisyse and Visian ICL. Verisyse IOLs are fabricated from a form of acrylic plastic known as PMMA, while Visian ICL is made (in part) from collagen. Both IOLs have been approved for patients over the age of 21 with moderate-to-severe nearsightedness.

Implantation of either phakic IOL option is similar, though there are several notable differences. Anesthetic eye drops are administered for both surgeries in order to minimize discomfort. The outpatient procedure is performed in less than an hour.

For Verisyse IOL implantation, a small incision is made and the IOL attached to the iris. The incision is then closed with small dissolvable stitches.
For Visian ICL IOL implantation, a smaller incision is made, through which the IOL (which may be folded) is inserted. It is then placed in front of the natural lens, but behind the iris. Unlike Verisyse, Visian ICL does not require any stitches.

Infection, inflammation, cataracts and an increased chance of detached retina is possible, albeit unlikely, following IOL implantation. Vision problems such as poor night vision, halos and increased eye pressure also may occur. Like INTACS, phakic IOLs, are reversible, differentiating them from other, permanent refractive surgery options. If necessary, a surgeon can remove the implants.

Phakic IOLs cannot be felt in the eye once implanted. Many patients find that their vision improves instantly, though it is not uncommon to require a day or two to recover.
The cost of phakic IOLs is approximately $3000. On average, implantable lenses tend to be more expensive than LASIK and other types of laser eye surgery.

Refractive IOLs

Refractive IOLs, or intraocular lens implants, are artificial lenses designed to be implanted inside the eye to correct vision problems such as cataracts. Refractive IOLs are implanted only after the natural lens of the eye has been removed – unlike some other forms of artificial lenses – in a process known as refractive lens exchange (RLE) surgery.

Refractive IOLs offer a good alternative treatment for people who may not be a candidate for other refractive procedures such as LASIK. Most patients are middle-aged or older, and have cataracts, or severe hyperopia (+6.00 diopters and higher). Refractive IOLs can also be used to treat presbyopia, an age-related condition in which the natural lens of the eye becomes less flexible, causing loss of the ability to focus at all distances.

RLE surgery is an outpatient procedure performed in approximately one hour. Anesthetic eye drops are used to numb the eyes and relieve any discomfort. An incision is then made in the front of the eye, allowing the surgeon to excise the natural lens and replace it with the refractive IOL. Depending on the length of the incision, surgery may require dissolvable stitches.

There are a number of different refractive IOL lens types that may be used, each of which is intended to address a specific vision problem. During an initial eye surgery consultation, the surgeon will advise the best lens option for a patient’s unique condition.

Although RLE surgery has a higher potential for risks and complications than its laser eye surgery alternatives, such issues are rare. Retinal detachment, dislocation of the IOL, over-correction or under-correction of vision, and infection are risk factors that will be discussed with the surgeon.

Refractive IOL recovery requires several days to a week away from work, driving and other routine activities. Patients may notice vision disruptions, such as poor night vision, and halos or glare for several weeks as the eyes heal. During this time, it is important to prevent eye irritation by avoiding activities such as contact sports or swimming.

The cost of refractive IOL surgery ranges from approximately $2,500 to $4,500 per eye, depending on the type of artificial lens being used. Unlike other refractive surgeries – which are considered elective – health insurance may cover some or all of the cost. For example, refractive IOLs used for cataract surgery will typically be covered by insurance.