Case Report: Cyclodialysis Cleft in a Case of Open-globe Injury and Role of Swept-source Anterior Segment Optical Coherence Tomography in Diagnosis.

SIGNIFICANCE: Cyclodialysis clefts can potentially develop secondary to open globe injury. The swept-source anterior segment optical coherence tomography (SS-AS-OCT) may be a valuable diagnostic tool for the identification and estimation of the circumferential extent of cyclodialysis clefts. It could be considered an alternative when ultrasound biomicroscopy cannot be performed successfully. PURPOSE: The purpose of this study was to report a case of open-globe injury associated with cyclodialysis cleft and the utility of SS-AS-OCT in its diagnosis. CASE REPORT: A 12-year-old boy presented to the clinic because of penetrating ocular trauma to his left eye with a projectile stone. He was diagnosed with limbal perforation with uveal tissue prolapse and cataract. He underwent limbal repair with cataract extraction and posterior chamber intraocular lens implantation. However, even at the 6 weeks' post-operative period, he did not gain vision and had persistent hypotony with hypotonic maculopathy. Gonioscopy showed a 2-clock-hour superonasal cyclodialysis cleft. However, on SS-AS-OCT, it was discovered that the cleft extended along 5 clock hours, involving both superonasal and inferonasal quadrants. Recognizing the large extent of the cleft, endocyclopexy by modified sewing-machine technique was planned and performed. An IOP spike and improvement in vision were noted on the next post-operative day. The SS-AS-OCT confirmed cleft closure. CONCLUSIONS: Although rare, cyclodialysis can occur in cases of open globe injury. The SS-AS-OCT is a useful diagnostic tool to study the circumferential extent of cyclodialysis and may unravel detachments hidden behind intact anterior ciliary body face.

Characterization of limbal explant sites: Optimization of stem cell outgrowth in in vitro culture.

Simple limbal epithelial transplantation (SLET) and cultivated limbal epithelial transplantation (CLET) are proven techniques for treating limbal stem cell deficiency (LSCD). However, the precise regions that are most suitable for preparing explants for transplantation have not been identified conclusively. Accordingly, this in vitro study aimed at determining ideal sites to be selected for tissue harvest for limbal stem cell culture and transplantation. We evaluated cell outgrowth potential and the expression of stem cell markers in cultures from 48 limbal explants from five cadaveric donors. The limbal explants were generated from the three specific sites: Lcor (located innermost and adjacent to the cornea), Lm (middle limbus), and Lconj (located outermost adjacent to the conjunctiva). We found that explants from the Lconj and Lm sites exhibited higher growth potential than those from the Lcor site. Transcript encoding the stem cell marker and p63 isoform, ΔNp63, was detected in cells from Lm and Lconj explants; expression levels were slightly, though significantly (p-value < 0.05), higher in Lm than in Lconj, although expression of ΔNp63α protein was similar in cells from all explants. Differential expression of ATP-Binding Cassette Subfamily G Member 2 (ABCG2) did not reach statistical significance. Immunohistochemistry by indirect immunofluorescence analysis of limbus tissue revealed that the basal layer in explant tissue from Lconj and Lm contained markedly more stem cells than found in Lcor explant tissue; these findings correlate with a higher capacity for growth. Collectively, our findings suggest that explants from the Lconj and Lm sites should be selected for limbal cell expansion for both CLET and SLET procedures. These new insights may guide surgeons toward specific limbal sites that are most suitable for stem cell culture and transplantation and may ultimately improve treatment outcomes in the patients with LSCD.

A validated porcine corneal organ culture model to study the limbal response to corneal epithelial injury.

Limbal epithelial stem cells are required for the maintenance and repair of the corneal epithelial surface. The difficulty in obtaining human corneal tissue for research purposes means that animal models for studying the corneal and limbal epithelium are extremely useful. Porcine corneal tissue represents an attractive experimental model, however, functional analysis of the limbal epithelial cell population is needed to validate the use of this tissue. Single cell clonal analysis revealed that holoclone-generating cells were enriched in the limbus as compared with the central cornea (38.3% vs 8.3%) and that label-retaining cells were also enriched in the limbus and compared with the central cornea (44.7 ± 6.4 vs 4.7 ± 1.5). Furthermore, it was demonstrated that in a 3D-printed organ culture system, porcine tissue was capable of maintaining and healing the corneal epithelium. Ki67 staining of corneal sections revealed that in response to central epithelial wounding, a greater proportion of progenitors in the basal limbal epithelium enter an actively dividing state. The authors present a comprehensively validated model system for studying the interactions between limbal niche factors and limbal epithelial stem cell fate.

The Impact of Limbal Mesenchymal Stromal Cells on Healing of Acute Ocular Surface Wounds Is Improved by Pre-cultivation and Implantation in the Presence of Limbal Epithelial Cells.

While limbal epithelial cells are used for treating ocular surface wounds, the therapeutic potential of mesenchymal cells cultivated from the limbal stroma (LMSC) is less clear. We have therefore examined the effects of LMSC when applied to acute ocular surface wounds. LMSC derived from male rabbits (RLMSC) were applied to the ocular surface of female rabbits immediately following removal of the corneal and limbal epithelium. Human amniotic membrane (HAM) was used as the vehicle for implanting the RLMSC. The effects of RLMSC were examined when applied alone (n = 3) and in conjunction with a stratified culture of human limbal epithelial cells (HLE) grown on the opposing surface of the HAM (n = 3). Outcomes were monitored over 3 months in comparison with animals receiving no treatment (n = 3) or treatment with HLE alone on HAM (n = 3). Animals treated with RLMSC (n = 6) displayed faster re-epithelialization (∼90% versus 70% healing after 12 weeks), with best results being observed when RLMSC were pre-cultivated and implanted in the presence of HLE (p < 0.01; 90% healing by 7 weeks). While all animals displayed conjunctival cells on the corneal surface (by presence of goblet cells and/or keratin 13 expression) and corneal neovascularization, evidence of corneal epithelial regeneration was observed in animals that received RLMSC in the presence of HLE (by staining for keratin 3 and the absence of goblet cells). Conversely, corneal neovascularization was significantly greater when RLMSC were applied in the absence of HLE (<0.05; 90% of cornea compared with 20-30% in other cohorts). Nevertheless, neither human nuclear antigen nor rabbit Y chromosome were detected within the regenerated epithelium. Our results demonstrate that while cultured LMSC encourage corneal re-epithelialization, healing is improved by the pre-cultivation and implantation of these mesenchymal cells in the presence of limbal epithelial cells.

Limbal ischemia: Reliability of clinical assessment and implications in the management of ocular burns.

PURPOSE: Limbal ischemia is an important prognostic factor in the management of ocular burns. In this study, we evaluated the reliability of clinically assessing limbal ischemia among ophthalmic professionals. METHODS: This study included 111 ophthalmic professionals who were shown 12 diffuse illumination color slit-lamp photographs of eyes with recent chemical injuries. Respondents were asked whether the photos were assessable and if yes, then to indicate the presence, location, and grade of limbal ischemia in each case. The responses were collected using a standard data collection sheet and the inter-observer agreement was calculated. RESULTS: All participants responded to every question. Of the 1,332 responses, images were deemed assessable in 1,222 (91.7%) instances. The overall agreement (Fleiss' kappa) for the presence of limbal ischemia and severity of limbal ischemia was 0.106 and 0.139, respectively (P < 0.012). Among the four groups of observers, practicing cornea specialists displayed significantly (P < 0.003) higher kappa values (0.201-0.203) when compared to residents (0.131-0.185), fellows (0.086-0.127), and optometrists (0.077-0.102). All indicated a poor level of inter-rater consistency. CONCLUSION: The results indicate that clinical assessment of limbal ischemia is highly subjective and there is lack of reliability even among cornea specialists who regularly manage patients with ocular burns. A non-invasive, standardized, objective, accurate, and reliable modality for ocular surface angiography is desperately needed for proper assessment and prognostication of ocular burns.

Iatrogenic limbal stem cell deficiency following drainage surgery for glaucoma.

OBJECTIVE: To describe conjunctival epithelial overgrowth of the cornea after surgery for glaucoma. METHODS: This is a retrospective case series (setting: Moorfields Eye Hospital). Fourteen eyes of 13 patients with suspected limbal stem cell deficiency (LSCD) and corneal conjunctivalization after glaucoma drainage surgery. Conjunctivalization was defined as corneal epithelium that demonstrated late stain after topical application of fluorescein. Patient demographics, clinical features, potential risk factors, treatment, and final visual acuity were recorded. Main outcome measures were potential risk factors for conjunctivalization, complications, and response to treatment. RESULTS: Eleven eyes had multiple procedures involving the limbus, and in 11 eyes mitomycin C (MMC) or 5 fluorouracil had been used as an adjunct to reduce fibrosis. Affected eyes typically had a segment of late stain with fluorescein based at the site of previous glaucoma surgery, but in one eye there was total loss of the corneal epithelial phenotype. All eyes previously had topical treatment for their glaucoma but only 2 had an ocular surface disease associated with LSCD. Most cases were asymptomatic, but in 3 eyes there was visual loss when the abnormal phenotype crossed the visual axis. In these 3 eyes there was recurrent epithelial breakdown, often at the interface between the 2 epithelial phenotypes. In one individual, these symptoms resolved after limbal epithelial transfer from the unaffected contralateral eye. CONCLUSIONS: Glaucoma drainage surgery can damage the adjacent corneal limbal epithelial stem cell population. This can be associated with recurrent epithelial breakdown and reduced vision. If there is visual loss, limbal epithelial transplantation is a potential treatment option.

Limbal cyst following blunt trauma in an operated case of congenital cataract: a rare scenario.

A 15-year-old male patient with the history of bilateral operated congenital cataract surgery 5 years back now presents with gradual painless diminution of visual acuity in left eye following a blunt trauma with a fist. Ocular examination showed a well-defined slightly bluish-tinged limbal-based conjunctival cyst without any irregularities in the anterior chamber/pupil. Intraocular pressures were 16 mm Hg in the right eye and 10 mm Hg in the left eye; retinal examination showed findings consistent with hypotonic maculopathy. Anterior segment ultrasound biomicroscopy revealed a well-defined limbal cyst with anterior chamber communication. Under local anaesthesia, the cyst was completely excised with the reconstruction of the sclerocorneal defect. At the end of 6 months, the patient is symptom-free with pretraumatic visual acuity.

Silk-Derived Protein Enhances Corneal Epithelial Migration, Adhesion, and Proliferation.

Purpose: The corneal surface is vulnerable to a myriad of traumatic insults including mechanical, chemical, and thermal injuries. The resulting trauma may render the naturally occurring regenerative properties of the cornea incapable of restoring a healthy epithelial surface, and may result in the loss of corneal transparency and vision. Healing of the corneal epithelium requires a complex cascade of biological processes that work to restore the tissue after injury. New therapeutic agents that act on the multiple steps of the corneal wound-healing process would offer a potential for improving patient outcomes. Here, a novel silk fibroin-derived protein (SDP) was studied for potential impacts on wound healing through studying an in vitro model. Methods: Solubilized SDP, produced from the Bombyx mori silkworm cocoon, was added to human corneal limbal-epithelial (hCLE) cultures to evaluate the material's effects on epithelial cell migration, proliferation, and adhesion through the use of various scratch wound assays and flow chamber studies. Results: Results indicated that the addition of SDP to culture increased hCLE migration rate by over 50%, and produced an approximate 60% increase in cell proliferation. This resulted in a nearly 30% enhancement of in vitro scratch wound closure time. In addition, cultures treated with SDP experienced increased cell-matrix focal adhesion formation by over 95% when compared to controls. Conclusions: The addition of SDP to culture media significantly enhanced hCLE cell sheet migration, proliferation, and attachment when compared to untreated controls, and indicates SDP's potential utility as an ophthalmic therapeutic agent.

AN ATYPICAL CASE OF SYMPATHETIC OPHTHALMIA AFTER LIMBAL CORNEAL LACERATION.

BACKGROUND/PURPOSE: To report a case of atypical sympathetic ophthalmia after limbal corneal laceration. METHODS AND RESULTS: An 11-year-old child had a successful left eye corneal laceration repair at the temporal limbus with excision of exposed nonnecrotic iris tissue, resulting in good visual acuity of 20/80 and 20/25 on postoperative Days 1 and 7, respectively. The patient was prescribed 1 mg/kg oral prednisolone in a tapering dose as prophylaxis. On postoperative Day 21, the patient presented with acute onset decreased vision in both eyes. Visual acuity was counting fingers 3 feet in both eyes. On examination, anterior segment examination was quiet without any inflammation, anterior vitreous face showed 1+ cells, and dilated funduscopy revealed bilateral symmetrical serous retinal detachments along the posterior pole. Optical coherence tomography demonstrated separation and elevation of inner neurosensory layers from the outer segment marking presence of hyperreflective material along with subretinal fluid between detached surfaces. There was stippled hyperfluorescence along the posterior pole as seen in fluorescein angiography. With a diagnosis of sympathetic ophthalmia confirmed, oral prednisolone (2 mg/kg body weight) was instituted after which, there was gradual decrease in macular elevation with corresponding improvement in visual acuity with no recurrence for the last 6 months. CONCLUSION: To our knowledge, this is the first reported instance of an atypical presentation of sympathetic ophthalmia, and antecedent corticosteroid therapy would have mitigated robust anterior segment findings usually associated with the condition.

Stability of limbal stem cell deficiency after mechanical and thermal injuries in mice.

We studied the reproducibility and stability of limbal stem cell deficiency (LSCD) in mice following controlled injuries to the corneal and limbal epithelia. In one method, corneal and limbal epithelia were entirely removed with a 0.5 mm metal burr. In the other, limbus to limbus epithelial removal with the burr was followed by thermal injury to the limbus. These two methods were compared with a previously published one. Unwounded corneas were used as control. The corneas were examined monthly for three months by slit lamp with fluorescein staining. Immunofluorescence staining for cytokeratin 12 and 8 on corneal wholemount and cross sections were performed to determine the phenotype of the epithelium. Mechanical shaving of the epithelium, with or without thermal injury, resulted in a reproducible state of LSCD marked by superficial neovascularization, reduce of keratin 12 expression and presence of goblet cells on the cornea. The phenotype was stable in 100% of the eyes up to at least three months. Thermal injury produced a more severe phenotype with more significant stromal opacification. These corneal injury models may be useful for studying the mechanisms leading to limbal stem cell deficiency.

A Comparative Study of the Therapeutic Potential of Mesenchymal Stem Cells and Limbal Epithelial Stem Cells for Ocular Surface Reconstruction.

UNLABELLED: Stem cell-based therapy has become an attractive and promising approach for the treatment of severe injuries or thus-far incurable diseases. However, the use of stem cells is often limited by a shortage of available tissue-specific stem cells; therefore, other sources of stem cells are being investigated and tested. In this respect, mesenchymal stromal/stem cells (MSCs) have proven to be a promising stem cell type. In the present study, we prepared MSCs from bone marrow (BM-MSCs) or adipose tissue (Ad-MSCs) as well as limbal epithelial stem cells (LSCs), and their growth, differentiation, and secretory properties were compared. The cells were grown on nanofiber scaffolds and transferred onto the alkali-injured eye in a rabbit model, and their therapeutic potential was characterized. We found that BM-MSCs and tissue-specific LSCs had similar therapeutic effects. Clinical characterization of the healing process, as well as the evaluation of corneal thickness, re-epithelialization, neovascularization, and the suppression of a local inflammatory reaction, were comparable in the BM-MSC- and LSC-treated eyes, but results were significantly better than in injured, untreated eyes or in eyes treated with a nanofiber scaffold alone or with a nanofiber scaffold seeded with Ad-MSCs. Taken together, the results show that BM-MSCs' therapeutic effect on healing of injured corneal surface is comparable to that of tissue-specific LSCs. We suggest that BM-MSCs can be used for ocular surface regeneration in cases when autologous LSCs are absent or difficult to obtain. SIGNIFICANCE: Damage of ocular surface represents one of the most common causes of impaired vision or even blindness. Cell therapy, based on transplantation of stem cells, is an optimal treatment. However, if limbal stem cells (LSCs) are not available, other sources of stem cells are tested. Mesenchymal stem cells (MSCs) are a convenient type of cell for stem cell therapy. The therapeutic potential of LSCs and MSCs was compared in an experimental model of corneal injury, and healing was observed following chemical injury. MSCs and tissue-specific LSCs had similar therapeutic effects. The results suggest that bone marrow-derived MSCs can be used for ocular surface regeneration in cases when autologous LSCs are absent or difficult to obtain.

The clinical characteristics of alcohol-related ocular rupture.

PURPOSE: To evaluate the characteristics and outcomes of drunken patients treated for ocular rupture, and to compare these results to patients injured without alcohol consumption. DESIGN AND METHODS: The medical records of 182 patients with or without alcohol consumption before injury who were treated and followed up because of ocular rupture at the Affiliated Hospital of Weifang Medical University from October 2007 to October 2011 were evaluated retrospectively. The characteristics and outcomes of 45 alcohol-related injury patients were compared with the rest in the cohort. The clinical data included in this study were: anatomic sites and length of the wound, involvement of ocular adnexa injuries, evisceration rate, and final mean visual acuity. RESULTS: Wound locations were significantly different between the alcohol-related group and the non-alcohol-related one. Compared with the non-alcohol-related ocular rupture population, the anatomic sites of the drunken patients were more likely to be located at zone I and zone II (60.0 vs 40.1 %; χ2 = 5.39,P < 0.05). The difference of wound length between the alcohol-related group and the non-alcohol-related one was significant. The alcohol-related patients had a longer wound length (Z = -8.590,P < 0.05). Compared with the non-alcohol population, the alcohol-consuming patients were more likely to suffer adnexa injuries (84.4 vs 59.8 %; χ2 = 5.86,P < 0.05), and had worse final visual acuities (Z = -7.195,P < 0.05). The evisceration rate of the alcohol-related patients was significantly higher than the non-alcohol patients (24.4 vs 9.4 %; χ2 = 6.62,P < 0.05). CONCLUSIONS: Drinking more easily leads to injury of the front part of eyes. Moreover, the drunken patients had a worse visual acuity outcome, longer wound length, higher evisceration rate, and were more prone to endure adnexa injuries. The importance of prevention and education to recognize the hazards of drinking cannot be overemphasized.

A rat model of autologous oral mucosal epithelial transplantation for corneal limbal stem cell failure.

PURPOSE: To establish an animal model of autologous oral mucosa grafting for limbal stem cell deficiency. METHODS: The study was carried from August to October 2012. Fourteen SD rats were randomly and evenly allocated to study group A and control group B. Limbal stem cell deficiency was established by alkali burn in the right eye of each rat in both groups. Rats in group A received autologous oral mucosa strip transplantation following the chemical burn. Rats in group B did not receive surgery after the chemical burn. Topical antibiotics and dexamethasone were used in all rats. Corneal clarity, corneal fluorescein staining, oral mucosal graft survival, and complications at postoperative days 1, 3, 7, 14 were observed. RESULTS: The oral mucosa strip graft was detached in one rat in group A. Reepithelialization was observed starting from the graft position and was completed within 14 days in the remaining 6 eyes in group A. However, persistent corneal epithelium defect was observed in all eyes in group B, among which corneal melting and perforation was observed in 2 eyes and corneal opacification with neovascularization was observed in the remaining 5 eyes. CONCLUSION: Autologous oral mucosa strip grafting for limbal stem cell deficiency can be achieved by a rat model following chemical burn. The fate of the transplanted oral mucosal epithelial cells warrants further study.

Successful simple limbal epithelial transplantation (SLET) in lime injury-induced limbal stem cell deficiency with ocular surface granuloma.

A 9-year-old boy presented with unilateral, total limbal stem cell deficiency (LSCD) complicated by the presence of a large fibro-vascular ocular surface mass lesion secondary to accidental lime injury. The pathological tissue covering the cornea was excised and simple limbal epithelial transplantation (SLET) was performed using autologous limbal tissue from the fellow eye. Histopathology of the excised ocular surface tissue revealed exuberant granulation tissue interspersed with retained calcium particles. At 6 weeks postoperatively, a focal recurrence of LSCD with symblepharon and forniceal shortening was noted superiorly. This was successfully managed by performing conjunctival autografting along with supplemental SLET. The unaided vision had improved from light perception at presentation to 20/40 at 6 months postoperatively. The fornices were deep and the corneal surface was avascular, epithelised and stable. This case demonstrates the efficacy of SLET in a child with severe ocular burns, highlighting the role of supplementary procedures customised to treat focal recurrences of LSCD.

Successful autologous simple limbal epithelial transplantation (SLET) in previously failed paediatric limbal transplantation for ocular surface burns.

A 3-year-old child sustained severe ocular surface burns in her left eye after accidental lime injury. Despite appropriate management in the acute stage, she developed limbal stem cell deficiency (LSCD) in that eye. This was initially treated with autologous ex vivo cultivated limbal epithelial transplantation (CLET), which unfortunately failed after 6 months resulting in recurrence of LSCD. One year following CLET, she underwent simple limbal epithelial transplantation (SLET) using autologous donor tissue from the healthy fellow eye. Successful restoration of the ocular surface following SLET combined with amblyopia therapy led to significant cosmetic and functional improvement. One year following SLET her vision in the left eye was 20/80 and she continues to maintain a stable, avascular and completely epithelised corneal surface. This case illustrates that SLET is effective in treating LSCD even in cases that are conventionally considered to be at high risk for failure of limbal stem cell transplantation.

[Efficacy of clinical evaluation in diagnosing injury zone in open globe ocular trauma]. / Eficacia de la evaluación clínica como prueba diagnóstica para identificar la zona de lesiónen un traumatismo ocular abierto.

BACKGROUND: Risk of retinal damage in open globe eye injuries increases as the zone (location of the wound vertex) is more rearward. The value of clinical exploration to assess this variable is unknown. OBJECTIVE: To establish the efficacy of clinical exploration as a diagnostic test to identify the injury zone in open globe ocular trauma. METHODS: Assessment of patients with open globe ocular trauma, preoperative clinical assessment of injury zone and surgical description of the wound were carried out. The proportion and 95% confidence intervals (CI) of eyes whose zone changed during surgical repair were established, and the efficacy of clinical evaluation to diagnose zone was estimated. Features of eyes with and without zone change were compared using χ(2) test. RESULTS: 89 eyes, mean age 27.1 years. Clinically, the identified zone was I in 36 eyes (40.4%), II in 38 (31.5%) and III in 25 (28.1%); the identified zone during surgery was I in 36 eyes (40.4%), II in 43 (48.3%) and III in 10 (11.2%). Zone changed in 30 eyes (34%, 95% C.I. 24 to 44). Specificity (96%), positive predictive value (93%) and positive likelihood ratio (13.9) were high only for zone II. No feature was associated with zone change. CONCLUSIONS: Clinical exploration was not efficient enough to identify injury zone in open globe trauma and has low prognostic value. It is not necessary to define the injury zone at first contact; it is enough identifying properly the agent, visual function and pupil reflexes for an efficient assessment.

Delayed loss of corneal epithelial stem cells in a chemical injury model associated with limbal stem cell deficiency in rabbits.

PURPOSE: Ocular injuries following exposure to the chemical agent sulfur mustard (SM) are characterized by acute corneal erosions and inflammation of the anterior segment that may be followed by delayed Partial Limbal Stem Cell Deficiency (LSCD), expressed clinically by corneal neovascularization and epithelial defects. LSCD may derive from direct destruction of limbal stem cells or indirectly from altered limbal stromal niche. The aim of this study was to investigate the mechanism underlying LSCD in SM injuries, focusing on the effects of the chemical on limbal epithelium. METHODS: Rabbit eyes were exposed to SM vapor and were observed by slit lamp examinations and pachymetry. Eyes were taken for histological and molecular biology evaluations at different time points (4 h-4 weeks), to include acute and delayed injuries. Epithelial stem cells were identified by ABCG2, p63 and by in vivo BrdU labeling for slow cycling cells. RESULTS: Limbal stem cells were not damaged during the acute phase following SM exposure, in contrast to the severe injury of the central corneal epithelium. On the contrary, limbal epithelium became activated, responding to corneal insult with a wound healing process, as shown by histology and by transient elevation of the stem cells markers. Simultaneously, inflammation was taking place in the limbal stroma lasting for weeks. A gradual loss of stem cells was observed later-on (2-4 weeks), associated with typical symptoms of LSCD. CONCLUSIONS: LSCD associated with SM ocular toxicity was not derived from a direct cytotoxic effect on the epithelial stem cells, but apparently from pathological events at the limbal stroma, that produced an abnormal microenvironment for the stem cells, triggering their gradual death. The results, and in particular the absence of a primary damage to the epithelial stem cells, indicate the presence of a therapeutic window for intervention to avoid the development of the delayed LSCD.

Concise review: limbal epithelial stem cell therapy: controversies and challenges.

Limbal epithelial stem cells (LESCs) are a population of stem cells responsible for maintenance and repair of the corneal surface. Injury and disease can result in a deficiency of these stem cells, the vision affecting condition called limbal stem cell deficiency (LSCD) in which the cornea becomes opaque, vascularized, and inflamed. Cultured LESC therapy was first described in 1997;29:19231932-19231932.and LESCs cultured from either patients or donors have been used to successfully treat LSCD. In this review, some of the challenges and controversies associated with cultured LESC therapy will be discussed including alternative stem cell sources.