Intracorneal Ring Segments (Intacs) for Keratoconus
Understanding Keratoconus and When Intacs May Help
Keratoconus weakens the structure of your cornea so that eye pressure and other biomechanical forces push it forward into an irregular cone shape. This bulging changes how light enters your eye, creating blurry vision, ghosting or monocular double vision, and distorted shapes. Many people with keratoconus find that straight lines appear wavy and that they become very sensitive to glare and bright lights.
The condition usually starts in your teens or early twenties and can get worse over time. Each eye may be affected differently, and the progression varies from person to person.
You may notice that your vision changes more quickly than it used to, requiring frequent updates to your glasses or contact lens prescription. Increased blurring, worsening halos around lights at night, and sharper sensitivity to glare can all signal progression.
- Needing a new prescription every few months
- Difficulty reading street signs or watching television
- More trouble driving at night due to halos and starbursts
- Eye discomfort or irritation that may lead to rubbing, which should be avoided
In the early stages of keratoconus, we can often correct your vision with glasses or soft contact lenses. As the cornea becomes more cone-shaped, specialized rigid gas-permeable or scleral lenses usually provide better vision because they vault over the irregular surface.
When even these advanced contact lenses no longer give you functional vision, or when you cannot tolerate wearing them comfortably, we may recommend surgical options such as Intacs. This stage means your cornea has progressed enough that reshaping it can help restore a clearer visual pathway.
Intacs are small, crescent-shaped plastic rings that we insert into the corneal stroma at a precise depth in the midperipheral zone of your cornea. Once in place, they add structure and push outward from within, which flattens the cone and redistributes pressure more evenly across the corneal surface.
This mechanical reshaping reduces the irregular astigmatism and can improve your vision enough to function better with or without corrective lenses. The segments help regularize the corneal shape and may improve your ability to wear contact lenses, though they do not reliably stop the underlying progression of keratoconus. If progression is a concern, corneal cross-linking is the treatment aimed at halting further weakening of the cornea.
Who Is a Candidate for Intacs
Your cornea must be thick enough to safely hold the ring segments without risking perforation or complications. Candidacy depends on the planned channel depth as a percentage of your local corneal thickness at the intended ring track, the specific device and segment model used, and the location of your cone.
If your cornea has thinned too much from keratoconus or has significant central scarring, we may need to consider other treatment options. Our testing will show us exactly where and how thick your cornea is in every zone, and we will determine whether your measurements support safe placement.
Intacs outcomes tend to be best for people with mild to moderate keratoconus who have reasonably good corrected vision potential and a clear central cornea. Your current prescription strength and the stability of your condition both play a role in determining candidacy.
- Clear central cornea without scarring in the visual axis
- Nearsightedness and astigmatism caused by the cone shape
- Contact lens intolerance or inadequate vision with lenses
- Realistic expectations that specialty contact lenses may still be needed after the procedure
Certain eye diseases or systemic health problems can make Intacs unsuitable for you. Active infections, severe dry eye, or corneal scarring in the area where we would place the segments can all interfere with healing and outcomes.
Autoimmune disorders that affect wound healing, uncontrolled diabetes, or connective tissue diseases may also increase your risk of complications. We will review your full medical history during your evaluation to identify any concerns.
Candidacy depends on your progression risk and treatment goals. If your keratoconus is actively worsening, corneal cross-linking is typically recommended to halt progression. Ring segments may be considered to improve visual function and contact lens tolerance, either before, after, or in combination with cross-linking, depending on your corneal findings and goals.
Age alone is not a strict barrier, but we look for signs that your condition has reached a stable phase or can be stabilized with cross-linking before or after placing the segments. Younger patients whose corneas are still actively progressing may need cross-linking first to prevent unpredictable results and reduce the need for additional procedures.
Testing and Evaluation Before Intacs
Corneal topography creates a detailed color-coded map of your cornea's surface, showing us exactly where the cone is located and how steep it has become. This imaging guides our decision about which size and thickness of ring segments to use and where to position them for the best effect.
We may take multiple topography scans at different visits to confirm that your keratoconus is stable. Consistent maps over time indicate that the condition is not actively worsening, making you a better candidate for the procedure.
Pachymetry uses ultrasound or optical technology to measure the thickness of your cornea at many points across its surface. These measurements ensure that your cornea is thick enough to safely create the tunnel for the ring segments without weakening it further.
- Identifies the thinnest zones that may limit placement options
- Confirms adequate depth for the surgical channel
- Helps predict healing and stability after the procedure
We will measure your best-corrected visual acuity with both glasses and specialized contact lenses to establish a baseline for comparison after surgery. Understanding how much vision you can achieve before Intacs helps us set realistic expectations and track improvement.
Your refraction, which determines your eyeglass prescription, shows the amount and type of refractive error caused by the cone. This information, combined with the topography, tells us how much correction the segments might provide.
Your consultation is the time to learn what Intacs can and cannot do for your specific situation. We encourage you to ask about the expected degree of vision improvement, the likelihood that you will still need corrective lenses afterward, and how this procedure fits into your long-term management plan.
- What are the risks and potential complications in my case?
- Will I need additional treatments like cross-linking?
- How many Intacs procedures has our eye doctor performed?
- What happens if my keratoconus continues to progress after Intacs?
- Are there alternative or complementary treatments I should consider?
The Intacs Insertion Procedure
We will give you specific instructions about medications to avoid before the procedure. If sedation is planned, you may be asked to stop eating or drinking for a period beforehand, so follow the specific instructions provided. You may also need to discontinue contact lens wear for a period before your final pre-operative measurements, with the timing depending on your lens type.
Arrange for someone to drive you home afterward, since your vision will be blurry and you may have received sedation or numbing drops that make it unsafe to drive. On the day of surgery, wear comfortable clothing and avoid wearing makeup, lotions, or perfumes around your eyes. Bring your current glasses or contact lens case if you wear lenses, and plan to rest at home for the remainder of the day.
After numbing your eye with drops, our eye doctor uses either a mechanical device or a femtosecond laser to create a small, circular tunnel within the corneal tissue. The tunnel is positioned at a precise depth and diameter to hold the ring segments securely without disturbing the front or back surface of your cornea.
Laser-assisted tunnel creation is commonly used when available and offers greater precision and may reduce the risk of complications compared to older manual techniques. The laser delivers extremely accurate cuts that match the exact curvature and depth needed for your specific segments.
Once the tunnel is ready, our eye doctor gently slides one or two curved segments into place through a tiny opening. The segments sit within the tunnel and begin to flatten the cone by pushing outward on the corneal tissue.
- Segments are made of a clear biocompatible plastic material
- Placement is adjusted to target the steepest part of the cone
- The entry incision is so small it usually does not require stitches
- You may feel pressure but should not experience pain
The entire Intacs procedure typically takes fifteen to thirty minutes per eye. We use topical numbing drops to keep you comfortable, and you may receive a mild sedative or oral medication to help you relax, depending on your preference and the facility protocol. Most patients remain awake and able to follow instructions.
Because the procedure is minimally invasive and performed on an outpatient basis, you will go home the same day. Some patients feel slight discomfort or a foreign body sensation immediately after the numbing wears off, but this usually improves within a few hours.
Recovery and Aftercare Following Intacs
Your eye will be sensitive to light, and your vision will be blurry for the first few days as your cornea begins to adapt to the new shape. You may notice tearing, mild discomfort, or a gritty feeling, all of which are normal parts of the healing process.
We recommend wearing the protective eye shield we provide, especially while you sleep, to prevent accidental rubbing or pressure on your eye. Avoid getting water, soap, or any irritants in your eye during the initial healing period.
We will prescribe antibiotic drops to prevent infection and anti-inflammatory drops, typically a corticosteroid, to reduce swelling and promote healing. Follow the dosing schedule carefully, and make sure to wash your hands before applying any drops. Do not stop the steroid drops early without our instructions, as this can affect healing. We will monitor your eye pressure and healing at your follow-up visits, especially if you are using steroid drops.
- Tilt your head back and pull down your lower eyelid to create a pocket
- Look up and squeeze one drop into the pocket without touching the tip to your eye
- Close your eye gently and avoid blinking hard for a few seconds
- Wait at least five minutes between different types of drops if you use more than one
Give your cornea time to stabilize around the new segments by avoiding strenuous activities, heavy lifting, and contact sports for at least one to two weeks. Swimming, hot tubs, and saunas should be avoided for several weeks to reduce infection risk.
Do not rub your eyes, even if they feel itchy, as this can dislodge the segments or cause inflammation. If you feel the urge to rub, use a cool compress over your closed eyelid instead.
We will see you the day after surgery to check that the segments are in the correct position and that your eye is healing well. Additional visits are typically scheduled at one week, one month, three months, and six months to monitor your corneal shape and vision improvement.
These appointments allow us to track how your cornea is responding and to update your glasses or contact lens prescription as your vision stabilizes. Consistent follow-up is essential to catch any issues early and ensure the best long-term outcome.
Contact our office right away if you experience severe pain, sudden vision loss, increasing redness, discharge, worsening light sensitivity, or a new white spot on your cornea. These symptoms could indicate infection, segment displacement, or other complications that require prompt attention. If you notice new flashes of light or floaters, contact us immediately, as these may signal a separate urgent eye issue.
- Sharp or worsening pain not relieved by over-the-counter pain medication
- Vision that becomes much worse instead of gradually improving
- Thick yellow or green discharge from the eye
- Feeling that the segment has moved or is visible at the edge of your cornea
As with any surgical procedure, Intacs carry potential risks that you should understand before proceeding. Most patients heal without serious problems, but complications can occur and may affect your vision or require additional treatment.
- Infection or inflammatory keratitis requiring antibiotics or segment removal
- Segment migration, exposure, extrusion, or need for repositioning or removal
- Glare, halos, or worsening night vision symptoms
- Fluctuating vision, undercorrection, overcorrection, or persistent irregular astigmatism
- Incision or channel complications such as epithelial defects, corneal haze, scarring, or rarely perforation
- Corneal thinning at the incision site or need for sutures
- Continued progression of keratoconus requiring cross-linking or other interventions
- Need for segment removal and consideration of corneal transplant in advanced cases
Results, Alternatives, and Next Steps
Most patients notice some improvement in vision within the first few weeks, but it can take three to six months for your cornea to fully settle into its new shape and for your vision to stabilize. During this time, the flattening effect continues as the cornea remodels around the segments.
Your final visual outcome depends on the severity of your keratoconus, the health of your cornea, and how well your eye responds to the reshaping. Visual improvement varies from person to person. Some people achieve significant improvement and can return to wearing glasses or soft contact lenses, while others mainly benefit from improved contact lens fit and tolerance rather than glasses-level vision.
One advantage of Intacs is that they are not permanent and can be removed or exchanged if needed. If your vision does not improve as expected, or if your keratoconus continues to progress, our eye doctor can take out the segments and consider other options.
We can also replace the segments with different sizes or thicknesses, or reposition them to target changes in your corneal shape. Removal is a straightforward procedure, though some residual refractive or topographic changes may persist after removal. This flexibility makes Intacs a reversible option compared to some other surgical treatments.
Many patients still need some form of vision correction after Intacs, and a significant number continue to require rigid gas-permeable or scleral contact lenses to manage residual irregular astigmatism. Some patients with favorable outcomes may be able to transition to softer or simpler corrective options, depending on how regular their corneal shape becomes.
We will recheck your prescription once your vision stabilizes and help you choose the best corrective option for your new corneal shape. The goal of Intacs is to make your vision more functional and your contact lenses more comfortable, even if you are not entirely glasses-free.
Corneal cross-linking uses ultraviolet light and riboflavin drops to strengthen the collagen fibers in your cornea and stop keratoconus from getting worse. The primary goal is to halt progression, though some patients also experience modest corneal flattening or visual improvement. Results vary, and improvement is not guaranteed.
Cross-linking is often recommended before, after, or in combination with ring segments when progression risk is present, to stabilize your cornea and protect the improvement gained from the segments. The timing and sequencing of cross-linking and ring segments is individualized based on your cone location, corneal thickness, degree of scarring, progression rate, and treatment goals. Combining both treatments may give you the best chance of long-term stability and functional vision.
Phakic intraocular lenses are implants placed inside your eye, in front of your natural lens, to correct high levels of nearsightedness or astigmatism that remain after Intacs. This option is considered when your cornea is too irregular for laser vision correction but you want to reduce dependence on glasses or contacts.
- Requires a healthy cornea and stable keratoconus
- Can be combined with Intacs if your corneal shape is improved enough
- Offers predictable correction for residual refractive error
- May have limitations if significant irregular astigmatism persists
If your keratoconus is too advanced, with severe thinning, scarring, or vision loss that cannot be helped by Intacs or other treatments, a corneal transplant may become necessary. Transplant surgery replaces the damaged cornea with healthy donor tissue and can restore clear vision when other options have been exhausted.
We reserve transplant for cases where the cornea is no longer structurally sound or where vision cannot be improved by less invasive means. Modern transplant techniques, including partial-thickness procedures such as deep anterior lamellar keratoplasty, offer good outcomes and have become safer over time.
Frequently Asked Questions
Intacs are designed to stay in place long-term, but they are not permanent and can be removed or replaced if your condition changes or if they do not provide the expected benefit. Removal is a straightforward procedure, though some residual refractive or topographic changes may remain after the segments are taken out.
Most people continue to need some form of vision correction after Intacs, but the prescription is often less complex and more comfortable than before. The procedure aims to improve your baseline vision and make corrective lenses more effective, rather than eliminate the need for them entirely.
Some insurance plans cover Intacs when they are medically necessary to treat progressive keratoconus that cannot be managed with glasses or contact lenses. Coverage decisions vary widely and depend on documentation of medical necessity, diagnosis coding, and your specific plan policy. Our office will help you verify benefits and obtain any required authorization before scheduling your procedure, but we cannot guarantee coverage.
We typically treat one eye at a time, waiting several weeks to months before addressing the second eye if needed. This approach allows us to monitor healing and results in the first eye and adjust our plan for the second eye based on what we learn.
Intacs can remain effective for many years as long as your keratoconus stays stable and the segments stay in proper position. Some patients keep their segments indefinitely, while others may need adjustments or additional treatments if their condition progresses or if their vision changes over time.
Intracorneal ring segments primarily reshape the cornea to improve vision and contact lens tolerance, but they do not reliably prevent the underlying progression of keratoconus in all patients. If your keratoconus continues to progress despite Intacs, we may recommend corneal cross-linking to halt further weakening, or we may adjust or remove the segments and explore other surgical options. Regular monitoring helps us detect progression early so we can intervene before significant vision loss occurs.
Getting Help for Intracorneal Ring Segments (Intacs) for Keratoconus
If you have been diagnosed with keratoconus and are struggling with blurry or distorted vision despite glasses or contact lenses, our eye doctor can evaluate whether Intacs might help you see more clearly. Schedule a comprehensive consultation to discuss your options, review your corneal health, and create a personalized treatment plan that fits your vision goals and lifestyle.