Lamellar keratoplasty using femtosecond laser intrastromal lenticule for limbal dermoid: case report and literature review

Treatment of Corneal Dermoid with Fibrin Glue Boned Multi-Layer Lenticules from Small Incision Lenticules Extraction Surgery: A Preliminary Study of Five Patients

PURPOSE

Dermoid excision combined with lamellar keratoplasty was one of the most common surgical techniques for corneal dermoid. Due to the huge shortage of corneal donors, small incision lenticule extraction (SMILE) derived lenticules might be the novel and feasible corneal grafts instead of traditional corneal donors. Therefore, we tried to use FG boned multi-layer lenticules as grafts in the treatment of corneal dermoid.

METHODS

Five patients (the oldest patient was 54 years old and the youngest case was 5 years old) were diagnosed with corneal dermoid and complaining of blurred vision or unsatisfied cosmetic appearance. All patients underwent corneal dermoid excision combined with FG boned multi-layer corneal lenticules transplantation. Slit-lamp microscopy and anterior-segmental optical coherence tomography(AS-OCT)were used to observe ocular appearance, corneal grafts survival, epithelialization, transparency, interlamellar fluid accumulation and the degradation of FG. The preoperative and postoperative change of best-corrected visual acuity (BCVA) and astigmatism were respectively recorded.

RESULTS

All patients were satisfied with the postoperative cosmetic results. BCVA had been increased and astigmatism had been decreased in all cases. We observed that the FG boned multi-layer corneal lenticules were covered with smooth corneal epithelium in one week after transplantation and successfully adhered to the corneal beds, without any dislocation or interlayer separation. FG was gradually degraded and absorbed within 1 month after surgery. The lenticule grafts grew well without rejection and kept transparency during the follow-up period.

CONCLUSIONS

FG boned multi-layer lenticules would be the novel and feasible substitute for lamellar keratoplasty in the treatment of corneal dermoid. FG could not be only used as binder adhering multi-layer lenticules, closing the interlayer space of multi-layer lenticules, preventing the formation of interlayer fluid, but also increasing the thickness and toughness of lenticules, and therefore which is more facilitate to intraoperative suture.

Sutureless lamellar keratoplasty with lenticule from small incision lenticule extraction for treating limbal dermoid: A case report

The present study reports the case of a superficial limbal dermoid surgically treated without suture by using a new technique of lamellar keratoplasty with allogenic lenticule from small incision lenticule extraction. The limbal lesion area was circumscribed by a trephine marker and lamellae were peeled off the anterior corneal stroma and sclera. After excision of the dermoid, the liquid on the bed was dried as much as possible and an appropriate stromal lenticule was attached to the implant bed without fibrin glue or suture. A bandage contact lens was applied to fix the graft. During postoperative follow-ups, the anterior segment optical coherence tomography, corneal refractive power, corneal topography and best-corrected visual acuity were examined to evaluate the surgical results. On the first day after the operation, the patient reported tearing and pain at the site. At one week after the operation, the patient reported no discomfort and conjunctival sutures were removed. At one month after the operation, the thickness of the lesion area was similar to that of the adjacent cornea, and the corneal curvature and refractive power of the lesion area were higher than that of the adjacent cornea. At three months after the operation, the patient was satisfied with the cosmetic outcome and no sign of corneal neovascularization, graft rejection or pseudo-pterygium formation was observed. The astigmatic error remained at 2.50 D. The present case provides insights into a potential treatment option for patients who need lamellar keratoplasty and may provide its benefit in contrast to conventional lamellar keratoplasty.

Allogenic Lenticular Implantation for Correction of Refractive Error and Ectasia: Narrative Review

INTRODUCTION

Intrastromal lenticule implantation is a promising treatment option for corneal pathologies, from refractive error to ectasia. In this narrative review, we intend to feature up-to-date literature supporting the use of lenticular tissue, a compelling method that can be customized for a variety of applications, providing an additional source of donor tissue for treating corneal diseases.

METHODS

We searched databases PubMed, Mendeley, and Scopus last accessed 10 May 2023, for literature on stromal lenticules and narrowed based on relevance. Review articles, animal studies, ex vivo studies, and book chapters were excluded, while assessable and relevant articles published in English were included.

RESULTS

Storage methods from using fresh lenticules to dehydration have proven successful, with cryopreservation maintaining structure and cellular viability for up to 10 years. Successful use of lenticules for treatment of numerous pathologies including corneal ectasias, hyperopia, and presbyopia with additional insight into the treatment of corneal ulcers and perforations are highlighted in this narrative review.

CONCLUSION

Lenticular implantation is an innovative and advantageous treatment for various ocular pathologies, offering increased bioavailability, flexibility, and customization for patients. They can treat previously untreatable diseases and serve as a replacement for synthetic implants, with promising outcomes worldwide. Lenticular implantation has the potential to become a leading approach in ophthalmologic surgery. Further studies should aim to provide evidentiary support for a standardization of lenticule banking.

Posterior corneoscleral limbus: Architecture, stem cells, and clinical implications

The limbus is a transition from the cornea to conjunctiva and sclera. In human eyes, this thin strip has a rich variation of tissue structures and composition, typifying a change from scleral irregularity and opacity to corneal regularity and transparency; a variation from richly vascularized conjunctiva and sclera to avascular cornea; the neural passage and drainage of aqueous humor. The limbal stroma is enriched with circular fibres running parallel to the corneal circumference, giving its unique role in absorbing small pressure changes to maintain corneal curvature and refractivity. It contains specific niches housing different types of stem cells for the corneal epithelium, stromal keratocytes, corneal endothelium, and trabecular meshwork. This truly reflects the important roles of the limbus in ocular physiology, and the limbal functionality is crucial for corneal health and the entire visual system. Since the anterior limbus containing epithelial structures and limbal epithelial stem cells has been extensively reviewed, this article is focused on the posterior limbus. We have discussed the structural organization and cellular components of the region beneath the limbal epithelium, the characteristics of stem cell types: namely corneal stromal stem cells, endothelial progenitors and trabecular meshwork stem cells, and recent advances leading to the emergence of potential cell therapy options to replenish their respective mature cell types and to correct defects causing corneal abnormalities. We have reviewed different clinical disorders associated with defects of the posterior limbus and summarized the available preclinical and clinical evidence about the developing topic of cell-based therapy for corneal disorders.

Update of Research Progress on Small Incision Lenticule Extraction (SMILE) Lenticule Reuse

The SMILE lenticule is a complete corneal stroma that is removed from SMILE surgery. Since the increasing number of SMILE surgeries, a large number of SMILE lenticules have been produced, so the reuse and preservation of the stromal lens has become a research hotspot. Due to the rapid development of the preservation and clinical reuse of SMILE lenticules, there have been many related studies in recent years, so we updated it on this basis. We searched PubMed, Web of Science, Embase, Elsevier Science, CNKI, WANFANG Data and other databases for all articles published on the preservation and clinical reuse of SMILE lenticules, screened useful articles, selected relevant articles published in the last five years as the main body for summary, and then reached a conclusion. The existing preservation methods of SMILE lenticule include Moist chamber storage at low temperature, cryopreservation technique dehydrating agent and corneal storage medium, which have their own advantages and disadvantages. Presently, smile lenticules can be used for the treatment of corneal ulcers and perforations, corneal tissue defects, hyperopia, presbyopia and keratectasia, which have been proven to be relatively effective and safe. More research on smile lenticule reuse needs to be carried out to confirm its long-term efficacy.

Tectonic keratoplasty using small incision lenticule extraction-extracted intrastromal lenticule for corneal lesions

Objective

This study investigated an alternative approach for obtaining donor corneas for keratoplasty that can be used in nations with high corneal demand and high costs for treatment of non-healing ulcers or lesions.

Methods

Eighteen patients (18 eyes) who underwent tectonic keratoplasty using small incision refractive lenticule extraction (SMILE)-extracted lenticule were included. Data were recorded regarding age, corneal status, corneal lesion location and size, preoperative and postoperative visual acuity, lenticule layer, and additional medical history.

Results

Corneal thinning and corneal perforation in 13 and 5 patients, respectively, were treated with tectonic keratoplasty using SMILE-extracted lenticule. After tectonic keratoplasty, globe integrity was maintained in 16 of the 18 patients. The mean decimal visual acuity improved from 0.2555±0.3326 preoperatively to 0.3303±0.3487 at the final follow-up. Visual acuity improvement was greater in patients with corneal perforation than in patients with corneal thinning. In addition, visual acuity was most improved in patients with infratemporal lesions.

Conclusion

Tectonic keratoplasty using SMILE-extracted lenticule is a comparatively safe, effective, and reliable alternative approach for the treatment of corneal lesions.

Recent developments in regenerative ophthalmology

Regenerative medicine (RM) is one of the most promising disciplines for advancements in modern medicine, and regenerative ophthalmology (RO) is one of the most active fields of regenerative medicine. This review aims to provide an overview of regenerative ophthalmology, including the range of tools and materials being used, and to describe its application in ophthalmologic subspecialties, with the exception of surgical implantation of artificial tissues or organs (e.g., contact lens, artificial cornea, intraocular lens, artificial retina, and bionic eyes) due to space limitations. In addition, current challenges and limitations of regenerative ophthalmology are discussed and future directions are highlighted.

Tectonic keratoplasty using femtosecond laser lenticule in pediatric patients with corneal perforation secondary to blepharokeratoconjunctivitis: a case report and literature review

Blepharokeratoconjunctivitis secondary to ocular demodicosis in the pediatric population is often neglected and may result in a serious sight-threatening condition. In severe cases, it can lead to corneal perforation necessitating urgent corneal transplantation. However, the shortage and high cost of donor corneas is the foremost limitation of keratoplasty in developing countries. Small-incision lenticule extraction is an advanced flapless femtosecond laser refractive procedure in which an intrastromal corneal lenticule is detached and removed to correct myopia and myopic astigmatism. We herein describe a technique in which lenticules are used for the management of corneal perforation secondary to Demodex-induced blepharokeratoconjunctivitis. The lenticule was sutured over the site of the perforated cornea using 10-0 interrupted nylon sutures. The globe integrity was maintained with a good visual outcome. Thus, tectonic keratoplasty using small-incision lenticule extraction appears to be a safe, cost-effective, and reliable alternative method for the management of corneal perforation secondary to blepharokeratoconjunctivitis.