At the World Cornea Congress IX (WCC IX), held from March 20–22, 2025, in Washington, D.C., over 1,200 ophthalmologists gathered to explore the latest advances in corneal surgery and clinical care. With a strong emphasis on innovation in corneal transplantation and vision correction, the event highlighted a number of cutting-edge developments shaping the future of patient care.
In this expert Q&A, we speak with Dr Samir Jabbour, Assistant Clinical Professor at the University of Montreal and Adjunct Clinical Professor at McGill University, who also practices at the Centre hospitalier de l’Université de Montréal (CHUM) and Jewish General Hospital (JGH). Dr Jabbour shares insights from his presentation on the evolving role of combining refractive procedures with corneal crosslinking (CXL) for patients with keratoconus and post-refractive ectasia. He discusses clinical indications, patient selection, benefits and risks of simultaneous versus sequential approaches, and the technologies driving the next wave of personalized corneal treatments.
What are the key clinical indications for combining refractive procedures with corneal crosslinking, and how do you determine patient eligibility?
Combining corneal crosslinking (CXL) with refractive procedures is indicated in patients with keratoconus or post-refractive ectasia who require both corneal stabilization and visual functional rehabilitation. Unlike laser vision correction aimed at spectacle independence, the goal here is to improve quality of vision. Ideal candidates often have suboptimal CDVA, intolerance to rigid or scleral lenses, or significant visual symptoms such as night vision disturbances. In select cases, corneal regularization with CXL and customized ablation can also aid in intraocular lens power calculations prior to cataract surgery. Patient eligibility is based on corneal tomography, sufficient pachymetry, visual potential and clear patient understanding of the treatment goals.
How has the integration of corneal crosslinking with refractive surgery evolved over recent years, particularly in the management of patients with early keratoconus or corneal instability?
The field emerged largely with the seminal Athens Protocol described by Kanellopoulos in 2009, which combined topography-guided PRK with corneal crosslinking to achieve both visual rehabilitation and biomechanical stabilization in keratoconus. Since then, a multitude of protocols have been published, many building on the concept of customized surface ablation. While topography-guided treatment remains the most studied, other approaches—including PTK-only ablation, wavefront-guided treatments, and hybrid techniques—have shown promising results. Overall, most protocols demonstrate good visual and refractive outcomes with acceptable safety profiles. However, no universal consensus has been reached on the optimal strategy, and treatment remains individualized based on patient characteristics and surgeon expertise.
What are the main benefits and potential risks of performing combined procedures?
Combining PRK with CXL offers the dual benefit of visual rehabilitation and biomechanical stabilization. The excimer laser can regularize the corneal surface and improve both uncorrected and best corrected visual acuity, while CXL halts disease progression by strengthening the corneal stroma. This combined approach can improve quality of life, reduce dependence on rigid contact lenses and potentially delay or avoid the need for keratoplasty. However, risks include increased postoperative haze, delayed epithelial healing, stromal scarring and reduced predictability of refractive outcomes due to the biomechanical changes induced by CXL. Careful patient selection, appropriate surgical planning and close postoperative monitoring are essential to maximize the benefits while minimizing complications.
Can you discuss the outcomes and long-term stability seen in patients undergoing simultaneous refractive correction and crosslinking compared to sequential treatments?
The Athens Protocol study demonstrated that the combined procedure—simultaneous topography-guided PRK and CXL—was superior to sequential treatment in terms of uncorrected and corrected distance visual acuity, as well as reduced haze formation. Advantages of the combined approach include faster visual rehabilitation, a shorter overall treatment timeline, avoidance of repeated epithelial trauma, potentially enhanced CXL efficacy due to better riboflavin diffusion and UV penetration, and the use of a more predictable nomogram, since ablation is performed on a non-crosslinked cornea. However, many centers continue to favor a sequential approach with good outcomes. Advantages of staging include the ability to confirm that CXL has effectively halted disease progression before proceeding with ablation. Disadvantages include removal of crosslinked anterior stromal tissue during the second procedure, reduced predictability of refractive outcomes due to altered corneal biomechanics, and the fact that standard nomograms are not applicable and require adjustment, increasing planning complexity. Additionally, sequential treatment involves two surgical episodes, which may prolong overall recovery. While the jury is still out on which technique is superior, the key remains adherence to a safe, effective and reproducible protocol tailored to individual patient needs.
Are there specific advancements in crosslinking protocols or refractive technologies that have enhanced the safety and effectiveness of combined procedures?
Recent advancements in imaging and refractive technologies are expected to significantly enhance the safety and effectiveness of combined procedures. While both topography-guided and wavefront-guided treatments offer distinct advantages and limitations, the emergence of high-resolution anterior segment imaging—such as OCT-based platforms like the Anterion and MS-39—and next-generation pyramidal aberrometers is enabling the creation of improved custom maps of higher-order aberrations. This progress allows for more precise treatment planning and the development of refined ablation profiles tailored to each patient’s unique corneal architecture. Additionally, emerging evidence suggests that the routine use of mitomycin C (MMC) in combined procedures may paradoxically increase the risk of haze in certain cases, prompting a re-evaluation of its standard use. Collectively, these innovations are expected to drive the development of newer, more effective nomograms that will further improve visual outcomes and reduce complications.
Interested in learning more about the World Cornea Congress IX? Take a look at the full programme here.
Support: No fees or funding were associated with the publication of this short article.
Cite: Jabbour S. Clinical pearls from WCC IX: Combined refractive procedures and crosslinking. touchOPHTHALMOLOGY. April 15th, 2025.
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