CREATE Protocol Shows Promise in Correcting RK-Induced Corneal Irregularity
Key Insights
A novel CREATE protocol, combining PTK and topography-guided ablation, significantly reduces corneal irregularity in post-RK patients.
The study showed a 69% reduction in higher-order aberrations and an 80.2% reduction when factoring in lower-order astigmatism and sphere.
50% of eyes treated with the CREATE protocol gained between 1 and 9 lines of vision, with 95% achieving 20/40 or better visual acuity.
The CREATE (Corneal Repair Epithelium and Topography Enhanced) protocol, a novel surgical approach, demonstrates significant promise in correcting corneal irregularity induced by radial keratotomy (search) (RK). The retrospective study, encompassing 60 eyes of 31 patients, showcases substantial improvements in visual acuity and reduction of higher-order aberrations (HOA) through a combination of phototherapeutic keratectomy (PTK) and topography-guided ablation.
CREATE Protocol: Methodology
The CREATE protocol addresses corneal irregularity by initially using PTK to remove the epithelium to the depth of epithelial compensation, as measured by optical coherence tomography. This step effectively creates an epithelial mask, removing the compensated stromal irregularity. Subsequently, WaveLight Contoura (search) is employed to treat corneal HOA and irregular astigmatism. In some cases, hyperopia (search) was preemptively treated to minimize post-operative hyperopia. Mitomycin C was applied topically after ablation.
Significant Reduction in Aberrations
The study revealed a remarkable 69% reduction in average HOA post-operatively. When lower-order astigmatism and sphere were factored in, the reduction reached 80.2%. This represents a significant improvement compared to previous RK repair studies that did not address epithelial compensation, which showed a 52.5% reduction in HOA and 46.6% reduction in grouped values. Statistical testing showed a p-value of 0.0369 between pre-op and post-op HOA values, indicating statistical significance.
Improved Visual Acuity
Visual acuity improvements were also notable, with 95% of eyes achieving a best-corrected distance acuity of 20/40 or better post-operatively, compared to 80.3% pre-operatively. Furthermore, 50% of the eyes gained between 1 and 9 lines of vision, and no eyes lost any lines of vision.
Sample Cases Highlight Success
Case studies included in the report further illustrate the effectiveness of the CREATE protocol. One case involved a 53-year-old male who experienced a 75% reduction in HOA and a significant improvement in the uniformity of the optical zone. Another case highlighted a patient who had previously undergone a Schwind corneal repair treatment with unsatisfactory results. The CREATE protocol significantly improved HOA reduction in this patient, from 31.6% after the Schwind treatment to 69.3% after the CREATE protocol.
Addressing Post-Operative Hyperopia
One challenge encountered with the CREATE protocol was the development of hyperopia (search) due to the flattening of the cornea. To mitigate this, the researchers began pre-emptively treating hyperopia during the initial corneal reconstruction, which improved patient satisfaction during the interim period before final refractive correction.
CREATE Protocol: A Promising Solution
The CREATE protocol offers a promising solution for correcting RK-induced corneal irregularity, providing significant improvements in visual acuity and reducing HOA. The technique is also being explored for other forms of corneal irregularity, including those resulting from LASIK/PRK, cataract surgery, trauma, infection, and keratoconus (search). According to the author, the goal of the CREATE Protocol is to restore vision by repairing the patient’s own cornea and relegate cornea transplant to only a small minority of extreme cases where it is not possible for the native cornea to be reconstructed.