From stem cells to synthetic implants, Monday’s mini-symposium revealed how next-generation corneal repair techniques are transforming the landscape of vision restoration.
Like the famously clear waters of Copenhagen’s harbor—once murky but now swimmable—the future of corneal repair is becoming increasingly transparent. On Monday morning, delegates gathered for the AAO Mini Symposium “Innovations in repairing the diseased cornea: from front to back”.
Co-chaired by Prof. Burkhard Dick (Germany) and Dr. Bennie Jeng (United States), six experts traced the cornea’s layers from stem cells to synthetic endothelium. Their talks spanned global labs and clinics, reflecting a shift toward scalable, cell-based and structure-guided therapies. The session served up a smörgåsbord of innovative techniques that could soon turn corneal blindness into a tale of yesteryear.
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Stem cells with diplomatic immunity
Dr. Victor Perez (United States) opened with cultivated limbal epithelial stem cells, one of the first genuine success stories in ocular regenerative medicine. For patients with unilateral limbal stem cell deficiency, autologous grafts have restored epithelial integrity, improved vision and reduced inflammation, all while avoiding the heavy burden of long-term immunosuppression. Yet for those with bilateral disease, the approach hits a wall when there is no healthy eye to donate from.
Dr. Perez’s laboratory is working to break through that barrier. His team has genetically modified allogeneic limbal stem cells to express PD-L1 (programmed death-ligand 1), essentially granting them diplomatic immunity against host immune rejection. “Generation of immune-regulated limbal stem cells expressing PD-L1 using lentivirus technology could be a way to expand therapy to many more patients and prevent blindness from stem cell deficiency,” he explained. Early data suggest these engineered cells retain their regenerative identity while gaining the stealth needed to evade immune attack.
His vision is to move from a therapy limited to unilateral cases toward a scalable solution that could extend treatment to patients with bilateral limbal failure worldwide. In corneal repair, Dr. Perez suggested, the future may lie in teaching donor cells the art of coexistence.
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When all else fails, bring in the Boston
For patients with end-stage ocular surface disease, the Boston Keratoprosthesis (KPro) is a last resort that can still deliver remarkable vision. Dr. Mona Harissi-Dagher (Canada), a global leader in the field, shared both long-term data and unforgettable patient stories. One chemical burn victim, blind for years after multiple failed grafts, regained 20/30 vision overnight following KPro implantation. “Now, 17 years later, he still has vision in that eye,” she noted, underscoring the device’s durability.
Her 15-year outcomes showed that 66% of patients maintained functional vision long-term and 90% retained their KPro device. Type 1 KPro is typically used in eyes with adequate tear film and blink, while Type 2 remains a solution for cicatrizing conditions such as Stevens-Johnson syndrome. Complications like glaucoma progression and retroprosthetic membrane formation remain challenges, but improved protocols and early intervention strategies are helping extend outcomes.
Dr. Harissi-Dagher stressed that success depends on teamwork, close follow-up and meticulous patient selection. She also paid tribute to the late Dr. Claes Dohlman, who pioneered the Boston KPro and opened the door for patients once left without hope. In her words, the device remains “a lifeline when nothing else works.”
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Stromal wizardry in three acts
Dr. Sayan Basu (India) turned attention to the corneal stroma, where scarring from infection and trauma remains a leading cause of blindness worldwide. “The global demand–supply gap for donor tissue is enormous,” he noted. “Bioengineering may be the only scalable path forward.”
Dr. Basu’s team is pursuing a three-pronged strategy. The first act features limbus-derived mesenchymal stem cells (L-MSCs), which in early clinical trials have restored corneal clarity and even encouraged nerve regeneration in eyes with post-infectious scarring or persistent epithelial defects. The second act involves cell-free, extracellular matrix–based hydrogels, made from donor byproducts, that can be applied like glue to enable scarless healing. The final act uses 3D bioprinting to create customized stromal scaffolds, potentially designed from patient-specific imaging data.
“Our clinical trials show that human limbus-derived mesenchymal stem cells can restore corneal clarity and potentially regenerate stromal and nerve tissue, offering transformative potential for corneal scars and wounds,” Dr. Basu reported, while showing dramatic before-and-after images.
Together, these approaches aim not only to rebuild transparency but also to make regenerative therapy accessible in regions where donor corneas are scarce. For millions facing preventable blindness, stromal bioengineering could prove to be the missing building block.
Natural lenticules: corneal recycling at its finest
Dr. Aylin Kilic (Turkey) highlighted intrastromal lenticule implantation, a technique that is both biologically elegant and practically sustainable. By processing donor corneal tissue into sterile, ready-to-use lenticules, surgeons can reshape recipient corneas without introducing synthetic materials. “This is not just a refractive tool,” Dr. Kilic emphasized. “It’s a practical, scalable alternative to keratoplasty—without the sutures, steroids or months of healing.”
Historically limited by variability, the method has been refined through laser shaping, custom design and standardized packaging, delivering predictable outcomes. Applications span from keratoconus stabilization to refractive correction, with lenticules fusing naturally into the native cornea. Unlike synthetic rings or implants, these natural inlays are fully biocompatible, preserve clarity and carry fewer long-term complications. Even modest visual gains, like a two-line improvement on the eye chart, can be life-changing in resource-limited settings.
Dr. Kilic likened the approach to a circular economy, where donor tissue unsuitable for full transplantation is given new life. By recycling what once might have gone unused, intrastromal lenticule implantation extends the value of each donor cornea. For patients and surgeons alike, it opens the door to a minimally invasive, reversible option that marries innovation with sustainability in the evolving landscape of corneal repair.
Cellular plumbers for leaky corneas
Prof. Jodhbir Mehta (Singapore) charted the evolution from selective endothelial keratoplasty to cell-based repair in a time when lab-grown endothelial cells are beginning to outpace donor grafts. “We are now in the era of cell-based endothelial replacement—moving beyond tissue transplantation, with clinical trials showing that cell injection or engineered grafts can restore function and clarity,” he said.
Japan recently approved neltependocel (Vyznova), the world’s first cell-based therapy for corneal endothelial disease, a milestone in the field. Early studies have shown lasting deturgescence and visual gains, with one cell injection potentially replacing up to 100 traditional grafts. In Singapore, Prof. Mehta’s team is testing tissue-engineered grafts built on decellularized stroma, while induced pluripotent stem cells (iPSC)–derived endothelial cells remain a longer-term prospect pending safety refinements.
The implications could reshape global care by reducing reliance on scarce donor tissue and broadening global access to corneal treatment. Yet Prof. Mehta cautioned that realizing this promise will require tackling the hard realities of cost, regulation and large-scale manufacturing. For now, endothelial cell therapy is both a triumph of innovation and a test of health system readiness to deliver regenerative treatments at scale.
Synthetic barriers as the last line of defense
Prof. Sorcha Ní Dhubhghaill (Belgium) closed the session with the EndoArt®, a synthetic, optically clear membrane designed for patients “at the end of the biological line.” Unlike cell-based therapies, this acellular implant replaces endothelial function with a passive barrier that controls corneal hydration, much like Copenhagen’s sea locks regulate the harbor’s flow.
“The EndoArt® is a thin, synthetic, optically clear barrier that replaces endothelial function without living cells—offering a simple, scalable solution for patients at the end of the biological line,” she explained. It has particular value in complex eyes with multiple failed grafts, glaucoma devices or keratoprostheses, where traditional approaches fall short.
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Implantation is relatively straightforward, but surgical precision is key. Descemet stripping and fixation sutures help prevent device detachment, while vigilant postoperative monitoring is needed to avoid complications such as over-dehydration or thinning. Early outcomes show reduction in pain and corneal swelling, with modest gains in vision that are often enough to improve quality of life in salvage cases.
Prof. Ní Dhubhghaill described the EndoArt® as a pragmatic, low-cost option that complements rather than competes with biologic therapies. In a field driven by high-tech cell science, this artificial endothelium simply reduces repair to its most practical form.
Rebuilding the cornea, piece by piece
The symposium showcased how corneal repair is becoming ever more personalized, with options carefully selected and arranged to meet individual needs.The vibrant Q&A sessions reflected the collaborative ethos that has made Denmark a design and innovation powerhouse.
Discussions ranged from technical surgical details to philosophical questions about the future of corneal transplantation in a world where donor tissue remains scarce. Cell-based therapies, bioengineered scaffolds, lenticules and artificial endothelium each unveiled new ways forward, less reliant on donor grafts and more on ingenuity. Challenges in regulation, cost and surgical delivery remain, yet the trajectory is solid.
In Copenhagen, the future of corneal repair is not just about replacing tissue, but about reimagining how we approach vision restoration altogether. And that’s a fairy tale ending even Hans Christian Andersen would approve of.
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Editor’s Note: The 43rd Congress of the European Society of Cataract and Refractive Surgeons (ESCRS 2025) was held from 12-16 September in Copenhagen, Denmark. Reporting for this story took place during the event. This content is intended exclusively for healthcare professionals. It is not intended for the general public. Products or therapies discussed may not be registered or approved in all jurisdictions, including Singapore.