Sutureless Femtosecond Laser–Assisted Anterior Lamellar Keratoplasty Using a Bioengineered Cornea as a Viable Alternative to Human Donor Transplantation for Superficial Corneal Opacities

Abstract

Purpose: To evaluate the safety and efficacy of a bioengineered corneal implant using femtosecond laser–assisted anterior lamellar keratoplasty for superficial corneal opacities. Methods: Six eyes of 6 consecutive patients with superficial corneal stromal opacities involving <220 μm owing to various pathologies were included in the study. Preoperatively, all patients underwent anterior segment optical coherence tomography (Visante; Carl Zeiss Meditec AG) to evaluate the depth of the corneal opacity. All patients underwent sutureless femtosecond laser–assisted anterior lamellar keratoplasty using a bioengineered collagen corneal implant (linkcor). Visual indices, refraction, and keratometry were evaluated preoperatively and 12 months postoperatively. Results: Corrected distance visual acuity improved significantly in all patients (P = 0.02). A significant decrease was seen in refractive astigmatism postoperatively (P = 0.04). Flat keratometry reduced significantly 12 months after the intervention (P = 0.04). No intraoperative or early postoperative complications were noticed. All implants were fully covered by healthy epithelium within a month after the surgery and remained clear at follow-up visits. The results of this procedure remained stable throughout the follow-up period. In 1 patient, mild inferior collagen melting and epithelial defect formation occurred at 1-year follow-up. Despite frequent topical corticosteroid therapy the melting progressed, the collagen tissue was removed and the patient was treated accordingly with good visual outcomes. Conclusions: Femtosecond laser–assisted anterior lamellar keratoplasty with bioengineered corneal (linkcor) implantation is an effective treatment for improving vision quality in anterior stromal opacities. This procedure reduces the need for human donor tissue and avoids human donor-related and suturing complications.

Bioengineered corneal tissue for minimally invasive vision restoration in advanced keratoconus in two clinical cohorts

“…A summary of recent clinical and preclinical studies of corneal bioengineering technologies is given in Supplementary Table 4. Most clinical studies, while having achieved significant advances in biomaterial properties, have addressed relatively rare causes of corneal blindness such as chemical burns 54,55 , infections [55][56][57][58] , ulcers 59 or high-risk cases 54,55 with the goal to stabilize the condition and avoid blindness, but not to optimize vision. Only two clinical studies to date have addressed keratoconus, a condition that impairs millions globally, aiming to provide vision gains comparable to standard PK or DALK.…”

Clinical applications of bioengineered tissue-cellular products for management of corneal diseases

“…To overcome the challenges of the recombinant collagen-based implant, the same group at Linköping University partnered with Farabi Eye Hospital in Tehran and All India Institute of Medical Sciences in New Delhi to develop a porcine-derived collagen type I implant to treat anterior stromal opacities. Their first-in-human trial in six patients demonstrated promising results with an improvement in mean BCVA to 0.26 logMAR, a decrease in mean cylinder by 1.0D, and an increase in mean stromal thickness by 47 μm postoperatively [39]. Five out of six patients had no complications at 1 year; one had a small area of melt that was managed successfully without a change in BCVA.…”

Advantages of femtosecond laser in various corneal transplantation procedures: A narrative literature review

“…[ 46 ] In 2020, Khodaparast et al . [ 48 ] demonstrated that FSL-assisted ALK using a bioengineered collagen corneal implant resulted in improved BCVA and astigmatism in 6 eyes with superficial corneal opacities, although the corneal implant was removed due to collagen melting in one eye. These results suggest that FSL can be a viable tool for the development of novel modified techniques of ALK.…”