Femtosecond laser-assisted implantation of corneal stroma lenticule for keratoconus

Abstract

Purpose To review recent progress, challenges, and future perspectives of stromal keratophakia for the treatment of advanced keratoconus. Methods We systematically reviewed the literature in the PubMed database, last update June 30, 2020. No language restriction was applied. The authors checked the reference lists of the retrieved articles to identify any additional study of interest. Results Several techniques have been proposed for the treatment of keratoconus in order to avoid or delay keratoplasty. This was primarily due to the lack of accessibility to donor corneas in many countries. The ease and predictability of the more advanced femtosecond lasers used to correct ametropias by stromal lenticule extraction lead to hypothesize that generated refractive lenticules could be implanted into corneal stromal layers to restore volume and alter the refractive properties of the cornea in patients with corneal ectasias. At the same time, new techniques for preservation, customization, and cellular therapy of the corneal stromal have been developed, directing to the valorization of otherwise discarded byproducts such as donor corneas unsuitable for either lamellar of penetrating keratoplasty. Conclusions Femtosecond laser-assisted stromal keratophakia could be a suitable therapeutic option for the treatment of corneal ectasias, especially in patients with advanced keratoconus, providing biomechanical support recovering the pachimetry to nearly normal value at the same time. The accuracy and predictability of the refractive outcome are yet a critical issue and the patient eligible for the procedure still has to be characterized.

Meniscus-Shaped Stromal Lenticule Addition Keratoplasty for Corneal Regularization and Thickening in Advanced Keratoconus

“…When compared to traditional keratoplasty (full thickness and DALK), the SLAK is able to reduce the immunological risks and postoperative intraocular hypertension, allowing for faster recovery and better patient compliance with its shorter surgical times and use of topical anesthesia. 5–7…”

“…When compared to traditional keratoplasty (full thickness and DALK), the SLAK is able to reduce the immunological risks and postoperative intraocular hypertension, allowing for faster recovery and better patient compliance with its shorter surgical times and use of topical anesthesia. [5][6][7] After the promising results found ex vivo, 8 the meniscus-shaped stromal lenticule addition keratoplasty (MS-SLAK) has been proposed as surgical management in patients with advanced KC. The aim of the study was to investigate the in vivo outcomes of the MS-SLAK technique in corneal regularization and thickness increase for advanced KC.…”

Comparison of Bowman-Stromal Inlay With Contralateral Eye Corneal Cross-linking Performed for Progressive Keratoconus

“…2 Kuechler et al 2 reported The other modality described to achieve keratoconus stabilization is host stromal augmentation with donor Refraction sph/cyl (D) OD (BSI) -6.00/-12.00 @ 145 -5.00/-13.00 @ 30 -6.00/-5.00 @ 30 -6.00/-3.50 @ 60 OS (CXL) -1.25 @ 130 -1.50 @ 110 -1.00 @ 130 - mid-stromal corneal tissue. 4 We chose the combined Bowman's layer and anterior stromal transplant (BSI) technique for the right eye of our patient after obtaining the informed consent of the patient's parents. 6 We noticed stabilization of ectasia in the right eye (BSI), which was the most remarkable finding because the result was similar to what we achieved with CXL.…”

“…2 In such scenarios, other modalities such as Bowman's layer transplant and various shaped corneal stromal lenticules in the host cornea have been described. [3][4][5] We recently published our work on combined Bowman's layer transplant and stromal augmentation (Bowman-Stromal Inlay [BSI]) to manage progressive keratoconus. 6 The surgery is technically simple and found to be effective in the stabilization of ectasia.…”

Effects of Corneal Stromal Lens Collagen Cross-Linking Regraft on Corneal Biomechanics

“…The recent development of small incision lenticule extraction (SMILE) surgery and SMILE-derived corneal stromal lens has shown promising effects in treating myopia (nearsightedness) and irregularly shaped cornea [ 3 , 4 ]. SMILE uses a femtosecond laser to regulate the thickness and size of the lens [ 5 , 6 ].…”