Surgical treatment of corneal dermoid by using intrastromal lenticule obtained from small-incision lenticule extraction

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.

An Efficient Technique for the Long-term Preservation of SMILE Lenticules Using Desiccation

PURPOSE

To evaluate a desiccation protocol for the long-term preservation of human small incision lenticule extraction (SMILE) lenticules and to study their integration in an in vivo rabbit model.

METHODS

Lenticules were retrieved after SMILE procedures in patients, then desiccated according to a novel protocol. Histologic and electron microscopic analyses were performed. Six rabbit eyes received grafts with an inlay technique, which consisted of inserting a desiccated lenticule into a stromal pocket. Rabbits were killed at different times between 6 and 24 weeks. Rabbit corneas were analyzed using optical coherence tomography, histology, and DAPI staining.

RESULTS

Microscopic analysis of desiccated lenticules showed a preserved stromal architecture after rehydration. A decellularization of the lenticules after desiccation was observed without any chemical treatment. All rabbit corneas remained clear after grafting human lenticules and no rejection occurred. Optical coherence tomography showed regular lenticular implantation and no decrease in lenticule thickness. Histologic analysis showed no inflammatory infiltration around lenticules and no nuclear material inside lenticules after 6 months.

CONCLUSIONS

A favorable integration of desiccated human SMILE lenticules in rabbit corneas was observed. The refractive issue of lenticular implantation must be investigated next. Clinical trials are needed to evaluate the use of desiccated SMILE lenticules to treat hyperopia or keratoconus in humans. [J Refract Surg. 2023;39(7):491-498.].

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.

Preoperative geometric parameters predict the outcome of lamellar keratoscleroplasty in patients with limbal dermoids

PURPOSE

To find preoperative simple geometric parameters to predict the outcome of lamellar keratoscleroplasty in patients with corneal limbal dermoids.

METHODS

We retrospectively analyzed the data of 30 patients with limbal dermoids who underwent lamellar keratoscleroplasty and were followed up for more than 6 months. Seven geometric parameters were used to analyze the relationship with postoperative visual acuity, astigmatism, and scar formation and investigated for their influence on postoperative outcome. These seven parameters included the cornea-invaded area of dermoid, dermoid area, the cornea-invaded length of dermoid, the corneal limbus invaded length of dermoid, dermoid size, bed size, graft size. Furthermore, we divided patients with corneal limbal dermoids into amblyopia group and non-amblyopia group, and analyzed the clinical characteristics of the amblyopia group.

RESULTS

The mean age of the patients at surgery was 10.6 ± 5.83 years. The 7 geometric parameters, preoperative and postoperative astigmatism of the amblyopia group were higher than those of the non-amblyopia group (all P < 0.05). Among the geometric parameters analyzed, the r coefficients between the cornea-invaded length of dermoid and postoperative visual acuity and astigmatism were the highest (r = 0.854, r = 0.714). The r coefficient between the corneal limbus invaded length of dermoid and the postoperative scar was the highest (r = 0.375). The r coefficient between age and postoperative steroid-induced high intraocular pressure was the highest (r = - 0.416). In univariate regression analysis, the cornea-invaded length of dermoid was significantly correlated with postoperative visual acuity (β = 0.270, P < 0.001) and postoperative astigmatism (β = 1.362, P < 0.001). Among the geometric parameters analyzed, the cornea-invaded length of dermoid had best stratified patients in grouping with or without amblyopia (cutoff > 2.24).

CONCLUSION

The cornea-invaded length of dermoid was the most important related factor of postoperative visual acuity, astigmatism, and amblyopia. The corneal limbus invaded length of dermoid was the most important related factor of postoperative scar formation. The geometric parameters and astigmatism in patients with amblyopia were larger than those in patients without amblyopia.

Visual and surgical outcomes of limbal dermoid excision at a tertiary care eye hospital

PURPOSE

To evaluate the presenting complaints, surgical management, surgical outcomes, complications, and postoperative visual acuity following limbal dermoid excision.

DESIGN

Retrospective cohort study.

METHODS

Medical records of patients with limbal dermoid presenting between January 2012 and December 2020 were retrieved to extract data regarding demographics, presenting profiles including the best-corrected visual acuity (BCVA), symptoms, anterior segment examination, and refraction. The outcomes included cosmesis, complications, graft transparency, and BCVA at the last follow-up.

RESULTS

Fifty-one eyes from 50 patients (27 males) were evaluated. The median age at the time of surgery was 11.5 years (interquartile range, IQR: 0.0-45.7). The median follow-up time was 5 years (IQR: 4-6). Goldenhar syndrome was noted in 5 patients (10%). The indications for surgery were cosmetic concerns (n  =  20, 39%), anisometropia (n  =  3, 6%), decreased vision (n  =  4, 8%), and growth or Dellen formation (n  =  2, 4%). Forty-eight were operated upon, opting for simple excision (n  =  12, 23.5%), amniotic membrane transplantation (n  =  16, 31.4%), lamellar keratoplasty (n  =  15, 29.4%), and penetrating keratoplasty (n  =  5, 9.8%). The most common complications were corneal scarring (n  =  19, 37.2%), corneal vascularization (n  =  2, 3.9%), and infection (n  =  1, 2%). Astigmatism > 1 D was observed in 34 (66.7%) eyes after dermoid management (p < 0.001). There were no complications in 14 eyes (27%), BCVA was > 20/60 in 43 eyes (84.3%), and only two eyes had BCVA < 20/400.

CONCLUSION

Surgical management of limbal dermoids offers promising functional and anatomic outcomes. However, postoperative astigmatism may require further follow-up and management.

Femtosecond Laser-Assisted Small Incision Allogeneic Endokeratophakia Using a Hyperopic Lenticule in Rabbits

Purpose

To investigate the morphologic and histopathologic changes in allogeneic endokeratophakia using hyperopic lenticules derived from small-incision lenticule extraction (SMILE).

Methods

Six New Zealand rabbits (12 eyes) were included in this experiment and randomly and evenly divided into donor and recipient groups. The donor group underwent bilateral hyperopic SMILE surgery, and the concave lenticules were implanted into eyes in the recipient group. Corneal topography and anterior segment optical coherence tomography (OCT) examinations were performed at 1 day, 1 week, 1 month, and 5 months after surgery. All eyes were enucleated 5 months after surgery. Hematoxylin and eosin (HE) staining and transmission electron microscopy (TEM) were used to observe the corneal morphology in the recipient group.

Results

No complications were observed, and the corneas remained transparent in the follow-up period. There was mild corneal edema within 1 week after surgery. Slit-lamp microscopy and OCT showed that the lenticules were gradually integrated with the surrounding corneal stroma. HE staining showed that the arrangement of corneal collagen was regular. The boundary between the lenticules and surrounding tissue could be identified with HE staining and TEM, and no inflammatory cells were found under TEM. The corneal Km values were significantly lower at 5 months postoperatively compared to preoperatively (P < 0.05).

Conclusions

This pilot study showed that allogeneic hyperopic SMILE lenticule endokeratophakia seems to be safe and feasible.

Translational Relevance

Allogeneic hyperopic SMILE lenticule endokeratophakia may be applicable for the correction of corneal regression, ectasia, ultra-high myopia, or keratoconus.

Bilateral Limbal Dermoid as an Isolated Finding in a Child

The authors report a case of a bilateral limbal dermoid in a 4-year-old girl with no extraocular anomalies or systemic associations. The child's best corrected visual acuity was 20/50 in the right eye and 20/40 in the left eye. There was a small limbal dermoid located on the inferotemporal side in the right eye and a large elevated limbal lesion that extended over the visual axis in the left eye. Limbal dermoid excision and lamellar keratoplasty were performed in the left eye and followed by a simple excision of the limbal dermoid in the right eye. Histopathological examination confirmed the clinical diagnosis of a dermoid. At the 2-year follow-up visit, the child's best corrected visual acuity had improved to 20/30 in both eyes. Tumors of the corneal limbus are extremely rare. Simple excision is a viable method of treatment for smaller, superficial lesions, although larger lesions can obstruct the visual axis and produce irregular astigmatism and amblyopia. In this patient, surgical intervention resulted in a reasonable cosmetic and final visual outcome. [J Pediatr Ophthalmol Strabismus. 2021;58(4):e27-e29.].

Treatment of Mooren's ulcer coexisting with a pterygium using an intrastromal lenticule obtained from small-incision lenticule extraction: case report and literature review

The coexistence of Mooren’s ulcer and a pterygium is an extremely rare ocular condition that has been infrequently reported in the literature to date. We herein present the first case of treatment of Mooren’s ulcer coexisting with a pterygium using a lenticule obtained by myopic small-incision lenticule extraction (SMILE). A 61-year-old woman presented with a 3-month history of recurrent ocular pain and red eye caused by Mooren’s ulcer coexisting with a pterygium. She received topical immunosuppressive and anti-infection treatments for almost 3 months. However, her ocular symptoms and signs did not substantially improve. Therefore, we performed lamellar keratoplasty with a corneal lenticule obtained by SMILE, followed by pterygium excision combined with conjunctival autografting. The patient recovered well with no complications or recurrence 1 year postoperatively. Our success suggests that combined surgery may be an effective management for coexistence of Mooren’s ulcer and a pterygium if conservative treatments fail. A corneal lenticule obtained by SMILE can be used as the lamellar keratoplasty graft in such patients.