For patients who had radial keratotomy (RK) years ago, finding clear and comfortable vision can be difficult. Irregular corneal surfaces, scarring, and visual distortions often remain long after surgery. New advances in scleral lenses technology offer renewed hope for these complex cases. Radial keratotomy was a popular refractive surgery in the 1980s and 1990s. Surgeons made spoke-like incisions in the cornea to flatten it and correct nearsightedness. The procedure helped many people reduce their dependence on glasses at the time.
While effective initially, many patients now experience vision problems decades later. The long-term effects of these corneal incisions were not fully understood when the surgery was popular.
The incisions made during RK permanently weaken the cornea's structure. Over time, this weakness can cause the cornea to change shape in unpredictable ways. These changes may lead to corneal instability and progressive vision shifts that are difficult to correct.
Higher-order aberrations (HOAs) are complex optical distortions that develop as the cornea becomes more irregular. Standard glasses and contact lenses cannot fully correct these aberrations. Many post-RK patients find that their vision quality declines over the years despite trying various correction methods.
Patients with post-RK vision problems often experience symptoms that affect daily life. These issues tend to be most noticeable in low-light conditions and can significantly impact quality of life.
Glasses correct simple refractive errors like nearsightedness, farsightedness, and regular astigmatism. However, they cannot address the irregular corneal surface left by RK incisions. The optical distortions caused by corneal scarring and irregularity require a different approach.
Soft contact lenses conform to the cornea's shape, so they follow its irregularities rather than masking them. This means soft lenses provide little benefit for most post-RK patients. Even standard rigid gas permeable lenses may not fully correct the higher-order aberrations present in many post-RK eyes.
Many post-RK patients feel frustrated after years of searching for good vision correction. Some had excellent results from their surgery for decades before problems developed. Others have tried multiple doctors and correction methods without finding a satisfactory solution.
Living with poor vision quality affects confidence, independence, and daily activities. Tasks that others take for granted, like driving at night or reading in dim light, become challenging or impossible. Understanding that effective options now exist can provide real hope.
Scleral lenses are large-diameter contact lenses that vault completely over the cornea. Unlike smaller contact lenses that rest on the cornea itself, scleral lenses rest on the white part of the eye called the sclera. This design allows them to bypass the irregular corneal surface entirely.
The space between the lens and the cornea fills with preservative-free saline solution. This creates a smooth, uniform optical surface that replaces the eye's damaged front surface. Light passes through this new smooth surface instead of the irregular cornea.
The fluid reservoir under a scleral lens acts like a liquid bandage over the cornea. It fills in the valleys and covers the peaks of an irregular corneal surface. This creates the smooth refracting surface needed for clear vision.
Because scleral lenses do not touch the central cornea, they avoid putting pressure on sensitive or scarred tissue. Many patients find them more comfortable than smaller rigid lenses that rest directly on damaged corneal areas.
Scleral lenses are very stable on the eye because of their large size. They do not move around or pop out during normal activities. The continuous layer of saline also keeps the eye hydrated throughout the day, which many patients find soothing.
Most patients adapt to scleral lens wear within a few weeks. While insertion and removal require practice, the techniques become routine with training and repetition.
Wavefront-guided scleral lenses go beyond standard scleral designs by adding custom correction for higher-order aberrations. These lenses use detailed measurements of the eye's complete optical system. The result is a lens that corrects complex distortions that standard designs cannot address.
Standard scleral lenses create a smooth front surface but use a simple optical prescription. Wavefront-guided lenses incorporate complex optical corrections built into the lens itself. This allows us to neutralize the specific aberrations present in each individual eye.
Higher-order aberrations are measured using Zernike polynomials. This is a mathematical system that describes optical irregularities in precise detail. Each Zernike order represents a different type of optical distortion.
Standard glasses correct up to the 2nd Zernike order, which includes defocus and regular astigmatism. Premium wavefront-guided scleral lenses can correct aberrations up to the 10th or 12th Zernike order. This addresses much more complex visual distortions that glasses cannot touch.
Creating wavefront-guided lenses requires sophisticated diagnostic equipment. High-resolution dynamic wavefront aberrometry measures how light travels through the entire optical system of the eye. These measurements create a detailed map of each eye's unique optical fingerprint.
The aberration data guides the design of custom lenses that correct each patient's specific distortion pattern. No two wavefront-guided lenses are exactly alike because no two eyes have identical aberrations.
Once measurements are complete, lens designers use the wavefront data to calculate the corrections needed. The optical zone of the lens is manufactured with precise surface modifications. These modifications are the opposite of the eye's aberrations, so they cancel each other out.
The manufacturing process requires specialized equipment capable of producing complex optical surfaces. Quality control ensures that the finished lens matches the prescribed design within tight tolerances.
Dr. Nathan Schramm, OD, FSLS, FBCLA, serves as a Principal Investigator for wavefront-guided scleral lens studies. His work examines how well these advanced lenses can correct higher-order aberrations in patients with corneal irregularities.
This clinical focus ensures we remain at the forefront of scleral lens technology. We apply these research insights directly to patient care, utilizing data to refine fit and optical performance for complex cases.
Research in this field demonstrates significant improvements in visual quality when comparing wavefront-guided designs to standard scleral lenses. These findings support the use of higher-order aberration correction for complex post-surgical cases.
For patients who have struggled with standard correction methods, these advanced designs offer a new pathway to clearer vision. The ability to correct specific optical distortions allows for a level of customization that was previously difficult to achieve.
Our experience confirms that higher-order aberrations can be effectively managed even in patients with severe corneal irregularities. The combination of stable scleral lens platforms and advanced wavefront optics provides a robust solution for post-RK eyes.
By mapping the unique irregularities of the post-surgical cornea, we can design lenses that mask distortions. This approach helps reduce the glare, halos, and ghosting that often plague RK patients.
The fitting process begins with a comprehensive eye examination. We will review your surgical history, current symptoms, and previous correction attempts. Corneal mapping creates a detailed picture of your corneal shape and any scarring present.
Wavefront analysis measures the higher-order aberrations in your optical system. Tear film assessment ensures your eyes can support comfortable lens wear. All of this information guides the lens design process.
Most patients try diagnostic lenses before ordering custom wavefront-guided designs. These trial lenses help determine the proper size, shape, and vault needed for your eyes. The fitting may require several visits to optimize the lens parameters.
Once a good physical fit is achieved, wavefront measurements are taken with the diagnostic lens in place. This shows how well the scleral lens alone corrects your aberrations and identifies what additional correction is needed.
After measurements are complete, your custom wavefront-guided lenses are ordered. Manufacturing typically takes several weeks because of the complexity involved. When the lenses arrive, you will return for a dispensing visit to verify the fit and vision.
Learning to handle scleral lenses takes practice. Our team will teach you the proper techniques for insertion and removal. Most patients become comfortable with these skills within one to two weeks of daily practice.
Special tools like plungers and insertion rings make handling easier. We will recommend the tools and solutions that work best for your situation.
Regular follow-up visits monitor your corneal health and lens condition. We will check that the lenses continue to fit properly and provide good vision. Adjustments to the prescription or lens design can be made if needed over time.
Insight Vision Center Optometry uses the Tomey WaveDyn Aberrometer to capture detailed measurements of the eye's optical system. This technology enables the creation of truly customized wavefront-guided scleral lenses for complex cases. We also use AS-OCT and Pentacam corneal tomography for comprehensive corneal evaluation.
Dr. Nathan Schramm, OD, FSLS, FBCLA, holds fellowships from the Scleral Lens Education Society and the British Contact Lens Association. He co-founded the International Congress of Scleral Contacts and serves as principal investigator for wavefront-guided scleral lens studies. Dr. Thanh Mai, OD, FSLS, FIAOMC, also holds an FSLS fellowship and provides scleral lens fitting using Pentacam corneal tomography.
Our team provides thorough training and ongoing support for scleral lens wearers. From initial fitting through long-term follow-up care, patients receive the guidance they need to succeed with their contact lenses.
Consider scheduling an evaluation if you had radial keratotomy and experience ongoing vision problems. This is especially important if glasses or standard contact lenses no longer provide satisfactory vision. Increasing difficulty with night driving or glare sensitivity are common reasons patients seek help.
Contact us promptly if you experience sudden vision changes, eye pain, significant redness, or new light sensitivity. While gradual vision changes are common in post-RK eyes, sudden symptoms may indicate a problem requiring immediate evaluation.
Yes. Many post-RK patients who could not achieve good vision with glasses, soft contacts, or standard rigid lenses find success with wavefront-guided sclerals. The custom aberration correction addresses optical problems that other lenses cannot correct.
Most patients find scleral lenses very comfortable once they adjust to them. Because the lenses rest on the sclera rather than the cornea, they avoid the sensitive central part of the eye. The fluid reservoir under the lens provides continuous hydration, which many patients find soothing.
Learning to handle scleral lenses takes practice, but most patients become comfortable within one to two weeks. Our team will provide hands-on training and support during the fitting process. Specialized tools make insertion and removal easier as you build confidence.
Some post-RK patients experience gradual vision changes over time due to ongoing corneal instability. Regular eye exams allow us to monitor these changes and update your lens prescription as needed. Many patients maintain stable, comfortable vision for years with proper follow-up care.
Scleral lenses often help patients with both corneal irregularity and dry eye symptoms. The saline reservoir bathes the cornea continuously throughout the day. Many patients with severe dry eye find scleral lenses more comfortable than other contact lens options.
With proper care, scleral lenses typically last one to two years before replacement is needed. The lenses require daily cleaning and disinfection using approved solutions. We will monitor the lenses at regular follow-up visits to ensure they continue to fit well and provide good vision.
