Posted by: Philadelphia Eye Associates in Eye Health, News on October 27, 2025
Written by Gregory Kraynak and edited by Brad Feldman, MD
Keratoconus is a progressive eye disease that causes the cornea to thin and bulge forward into a cone-like shape. This irregular curvature results in distorted vision, glare, and significant astigmatism. When keratoconus is severe, patients may require a cornea transplant. However, Corneal Tissue Addition Keratoplasty (CTAK) is a novel, less invasive alternative that can restore vision and improve corneal curvature without the need for a full cornea transplant. Unlike rigid contact lenses or corneal cross-linking, CTAK directly reshapes the cornea by adding customized donor tissue. This structural inlay improves both the surface contour and visual function, often resulting in clearer, less distorted vision.
The donor corneal tissue in CTAK comes from accredited eye banks and meets all Eye Bank Association of America (EBAA) safety standards. To enhance safety and compatibility, cells in the donor tissue are inactivated by freezing, and gamma radiation is used to sterilize the tissue. This sterilization reduces the chance of contamination by bacteria or fungi. The preserved tissue is cut to shape using a femtosecond laser (the same laser used in LASIK surgery) before placement in the patient’s cornea.
What makes CTAK unique is its personalization. Every cornea has different curvature and thinning patterns, so treatment needs to be tailored to each patient. First, multiple imaging modalities map the corneal shape, elevation, and thickness. Then, a surgical plan determines the optimal size, angle, and placement of the donor inlay. Finally, a femtosecond laser precisely cuts the donor tissue, ensuring a perfect fit for each patient’s corneal anatomy. This level of customization is what allows CTAK to restore corneal smoothness and symmetry effectively.
CTAK surgery is usually performed under local or topical anesthesia with or without sedation. The surgeon uses a femtosecond laser to create a channel in the cornea that matches the prepared customized donor inlay. The inlay is then gently inserted into the channel, restoring thickness and reducing cone-like distortion.
The entire surgery typically takes 45 minutes. During the procedure, patients focus on a light target. They may hear quiet instrument sounds but should not feel pain. The surgical team provides ongoing guidance to ensure comfort.
Immediately after surgery, the eye is covered with a protective patch to prevent injury and promote healing. Mild discomfort, tearing, redness, and light sensitivity are common during the first days but usually improve quickly. Patients start on a corticosteroid drop after the procedure to reduce inflammation and an antibiotic drop to prevent infection. Artificial tears such as Refresh or Systane may be recommended to relieve dryness. Patients should avoid rubbing the eye, strenuous exercise, heavy lifting, and contact sports for at least 1 week to prevent displacement or injury. Wearing UV-protective sunglasses outdoors is important to shield the healing cornea from sun and wind. Follow-up appointments are required to make sure the eye is healing properly and to check for changes in glasses and contact lens prescriptions. Typical visits occur one day, one week, one month, and three months post-surgery to monitor the healing process and watch for any complications. After CTAK, most patients will notice an improvement of vision in the first week. The vision will fluctuate over the course of the first few days and weeks and stabilize around 4 weeks after the procedure. Patients are advised to wait at least 4 weeks before being fitted with new glasses or contacts.
Potential candidates for CTAK include individuals with keratoconus who have sufficient healthy cornea to support a donor inlay. Candidates must not have any uncontrolled eye disease, severe dry eye, or active infections. Lastly, some patients may not be candidates if they have had certain prior surgeries or autoimmune conditions that might interfere with healing. A full consultation includes pachymetry to measure corneal thickness and corneal mapping by means of topography or tomography to determine eligibility.
Although CTAK is less invasive than a corneal transplant, it is still a surgical procedure. The main risks associated with CTAK include infection or inflammation or scarring. The antibiotic drops and corticosteroid drops are vital to minimizing these risks. A third risk is unexpected or worsened corneal shape, which could be corrected by removing the added corneal tissue. If the first CTAK results in an unfavorable outcome, it may be possible to reshape the tissue inlay and perform CTAK a second time.
Symptoms such as persistent redness, pain, light sensitivity, or sudden vision changes require prompt medical attention. Early recognition and treatment of complications improve outcomes.
Clinical studies showed excellent results from CTAK:
Individual improvements included:
These outcomes highlight CTAK’s potential to offer long-lasting vision improvement and greater quality of life.
CTAK represents a significant step forward in keratoconus management. If you have keratoconus and are experiencing progressive vision changes, CTAK may be an option worth discussing with one of our corneal specialists.
Further Reading and Support
_______________
1. Corneal & Laser Eye Institute. Keratoconus and Corneal Tissue Addition Keratoplasty (CTAK). https://www.vision-institute.com/keratoconus-new-jersey/surgical-procedures-keratoconu s/corneal-tissue-addition-keratoconus-ctak/
2. Ballouz, Dena et al. “Corneal Tissue Addition Keratoplasty for the Treatment of Keratoconus: A Review.” International ophthalmology clinics vol. 65,2 (2025): 31-34. doi:10.1097/IIO.0000000000000561
3. Greenstein, Steven A et al. “Corneal tissue addition keratoplasty: new intrastromal inlay procedure for keratoconus using femtosecond laser-shaped preserved corneal tissue.” Journal of cataract and refractive surgery vol. 49,7 (2023): 740-746. doi:10.1097/j.jcrs.0000000000001187
4. Corneal & Laser Eye Institute. CTAK Recovery: What To Expect After The Procedure. https://www.vision-institute.com/navigating-post-ctak-recovery-what-to-expect/
8025 Roosevelt Blvd.
Philadelphia, PA 19152
