Unilateral Total Limbal Stem Cell Research Articles

Simultaneous simple limbal epithelial transplant and Descemet’s stripping automated endothelial keratoplasty for a case of presumed “Munchausen syndrome by proxy”: A novel surgical technique

We attempt to introduce the technique of the application of simple limbal epithelial transplantation (SLET) and Descemet stripping automated endothelial keratoplasty (DSAEK) in the same eye at the same sitting for a case of unilateral total limbal stem cell deficiency (LSCD) with endothelial decompensation and scarring. The operated eye showed significant healing within 6 months of the surgery. To our knowledge, this is the first case of unilateral total LSCD with endothelial decompensation and scarring managed by both SLET and DSAEK in the same eye.

Conjunctival Limbal Autograft Combined with Amnion-Assisted Conjunctival Epithelial Redirection for Unilateral Total Limbal Stem Cell Deficiency after Severe Chemical Burn.

(1) Background: To evaluate the efficacy of conjunctival limbal autograft (CLAU) combined with the amnion-assisted conjunctival epithelial redirection (ACER) procedure for patients with unilateral total limbal stem cell deficiency (LSCD) caused by severe chemical burn. (2) Methods: A retrospective interventional case series of unilateral total LSCD after chemical burn who underwent CLAU combined with ACER surgery between September 2021 and July 2023 was collected. Outcome measures included epithelialization of the cornea with donor limbus-derived epithelium, best corrected visual acuity (BCVA), and complications. (3) Results: Nine males and one female were included in this study. The mean age was 40.9 ± 9.63 (range, 26 to 55) years. The average duration between injury and CLAU combined with the ACER procedure was 7.67 ± 3.97 (range, 4 to 18) months. All patients achieved corneal epithelialization and improved BCVA. Postoperative complications occurred in four cases, including delayed corneal epithelial healing in one case, delayed amniotic membrane dissolution and detachment in two cases, and recurrence of symblepharon in one case. No complications were noted in the healthy donor eyes. (4) Conclusions: CLAU combined with ACER is a safe and effective treatment for unilateral total LSCD caused by severe chemical burn. This combined surgery restores visual function for patients with corneal blindness caused by chemical burn, reducing the burden on the families and society.

Understanding Ocular Surface Inflammation in Tears Before and After Autologous Cultivated Limbal Epithelial Stem Cell Transplantation.

We aimed to determine the expression of inflammatory cytokines in the tears of patients with unilateral total limbal stem cell deficiency (TLSCD) caused by chemical burns before and after autologous cultivated limbal epithelial stem cell transplantation (CLET). Tear samples were collected from both eyes of 23 patients with unilateral TLSCD and 11 healthy controls, at fixed timepoints before and after CLET. Dissolved molecules were extracted from Schirmer's strips using a standardised method and analysed on an array plate of ten inflammatory cytokines (V-Plex Proinflammatory Panel 1 Human Kit, MSD). IL1β expression was significantly elevated in the TLSCD eye compared with the unaffected eye at baseline (p < 0.0001) but decreased to normal 3months post-CLET (p = 0.22). IL6 and IL8 were unaffected at baseline but significantly elevated in the TLSCD eyes at 1month post-CLET (p = 0.001 and p < 0.0001, respectively). IL6 returned to normal at 3months and IL8 at 6months post-CLET. There was a significant renewed increase in IL1β, IL6 and IL8 expression at 12months post-CLET (p < 0.0001, p = 0.0001 and p = 0.0003, respectively). IFNγ, IL10 and IL12p70 expression were significantly reduced in both eyes of patients with unilateral TLSCD at all timepoints. IL1β is a specific marker of inflammation in TLSCD eyes that could be therapeutically targeted pre-CLET to improve stem cell engraftment. At 12months post-CLET the spike in levels of IL1β, IL6 and IL8 coincides with cessation of topical steroids, suggesting ongoing subclinical inflammation. We therefore recommend not discontinuing topical steroid treatment in cases where penetrating keratoplasty is indicated; however, further investigation is needed to ascertain this. European Union Drug Regulating Authorities Clinical Trials Database (EuDRACT 2011-000608-16); ISRCTN (International Standard Randomised Controlled Trial Number (isrctn51772481).

Mini-Conjunctival Limbal Autograft (Mini-CLAU) Using Platelet-Rich Plasma Eye Drops (E-PRP): A Case Series.

The purpose of this study was to introduce a new method of limbal stem cell transplantation using autologous platelet-rich plasma (E-PRP) eye drops for unilateral total limbal stem cell deficiency. Patients with total unilateral limbal stem cell deficiency due to chemical burn underwent mini-conjunctival limbal autograft using autologous E-PRP drops. One small limbal block, measuring 2 × 2 mm, was harvested from the patients' contralateral healthy eye and transplanted to the diseased eye. All patients received E-PRP drops until achieving complete corneal epithelialization. Subsequent corneal transplantation was performed in eyes with significant stromal opacification. Corneal buttons obtained during corneal transplantation underwent immunohistochemistry for the evaluation of limbal stem cell markers (ABCG2 and P63). Visual acuity, epithelial healing, corneal clarity, and regression of corneal conjunctivalization/vascularization were evaluated after surgery. Ten patients with acid (n = 7) or alkali (n = 3) burn were included. The mean follow-up period was 21.7 ± 5.8 months (range, 12-32 months). Corneas were completely reepithelialized within 14.9 ± 3.5 days (range, 11-21 days). Corneal conjunctivalization/vascularization dramatically regressed 1 to 2 months after surgery in all cases, and corneal clarity considerably improved in 7 patients. In the 3 eyes with significant stromal opacification, subsequent optical penetrating keratoplasty was performed. The ocular surface was stable throughout the follow-up period in all eyes. BSCVA improved to 0.60 ± 0.0.32 and 0.46 ± 0.0.25 logMAR in eyes with and without corneal transplantation, respectively, at the final follow-up visit. ABCG2 and P63 markers were detected on corneal buttons after keratoplasty. Based on our clinical and laboratory findings, mini-conjunctival limbal autograft using E-PRP can be considered as a promising alternative to ocular surface reconstruction.

Long-term outcomes of conjunctival limbal autograft in patients with unilateral total limbal stem cell deficiency

PurposeTo investigate the long-term clinical outcomes of conjunctival limbal autograft (CLAU) in patients with unilateral total limbal stem cell deficiency (LSCD). MethodsIn this retrospective interventional case series, the medical charts of patients with unilateral total LSCD were reviewed. Patients who underwent CLAU and no other allograft ocular stem cell transplantation with a minimum follow-up of 1 year were included. Main outcome measures were ocular surface stability, best-corrected visual acuity (BCVA), and postoperative complications. Results27 eyes fulfilled the inclusion criteria with a mean follow-up period of 49.8 ± 36.6 months (4.15 years; range 12–186.72 months; 1–15.56 years). Ocular surface stability was achieved in 77.8% (n = 21) of eyes at last follow-up, while 22.2% (n = 6) developed partial surface failure. Optical penetrating or deep lamellar anterior keratoplasty was performed in 44.45% (n = 12). BCVA improved from 1.42 ± 0.95 mean LogMAR (equivalent to 20/400) preoperatively to 0.53 ± 0.47 mean LogMAR (equivalent to 20/70) at last follow-up (p < 0.001). BCVA ≥20/40 was achieved in 44.45% (n = 12) at last follow-up. Microbial keratitis occurred in 14.81% (n = 4). Ocular hypertension secondary to corticosteroid use developed in 25.9% (7/27) eyes. There were no other complications in the donor or recipient eyes. ConclusionsCLAU can provide long-term ocular surface stability and successful visual outcomes in patients with unilateral LSCD.

Outcomes of Penetrating Keratoplasty Following Autologous Cultivated Limbal Epithelial Stem Cell Transplantation.

The purpose of this study is to investigate the outcomes of penetrating keratoplasty (PKP) following autologous cultivated limbal epithelial stem cell transplantation (CLET). A prospective, single center, interventional cohort study investigating patients with unilateral total limbal stem cell deficiency (LSCD) treated with CLET who underwent PKP. Patients with confirmed corneal re-epithelialization > 6 months post-CLET, and with best-corrected visual acuity (BCVA) <0.3 logMAR were offered PKP. CLET survival assessed by slit lamp, corneal impression cytology (CIC), and in vivo confocal microscopy. Confirmation of corneal re-epithelialization by histological and immunocytochemical (ICC) examination of trephined corneal buttons. Mean change in best-corrected visual acuity (logMAR) following PKP and PKP survival at 12 months were calculated. Twenty patients underwent PKP. Mean time of PKP was 19 months (range 11-41 months, SD 7.26) post-CLET. Median follow-up time post-PKP was 15 months (range 1-32, SD 10.2). CIC and ICC of all corneas confirmed corneal re-epithelialization before PKP. Mean pre-PKP BCVA was 1.46 (range 0.3-2.7, SD 0.94) improving to a mean post-PKP BCVA of 0.74 (range 0-2.7, SD 0.87); mean improvement in BCVA post-PKP of 36 letters (95% CI 15.0-57.1, p = .002). Kaplan-Meier mean graft survival was 90.9% (95% CI 50.8-98.7) at 12 months. We recommend a two-stage approach with CLET followed by PKP >12 months later. Patients experienced a significant improvement in BCVA following PKP. PKP did not have a detrimental effect on CLET survival. PKP survival post-CLET is better than that reported for high risk PKP. Stem Cells 2018;36:925-931.

Variations in the technique for autologous limbal transplantation

Abstract Objective To present the results on the use of a single block limbal autograft, combined with amniotic membrane transplantation and sectoral sequential postoperative epitheliectomy of the conjunctiva in 2 patients with unilateral total limbal stem cell deficiency. Conclusions A single block limbal autograft combined with amniotic membrane transplantation may be sufficient to restore a stable corneal surface, but sometimes sequential sectoral conjunctival epitheliectomy may be required to treat anomalous epithelial remnants.

Variaciones en la técnica del trasplante limbar autólogo

ObjectiveTo present the results on the use of a single block limbal autograft, combined with amniotic membrane transplantation and sectoral sequential postoperative epitheliectomy of the conjunctiva in 2 patients with unilateral total limbal stem cell deficiency. ConclusionsA single block limbal autograft combined with amniotic membrane transplantation may be sufficient to restore a stable corneal surface, but sometimes sequential sectoral conjunctival epitheliectomy may be required to treat anomalous epithelial remnants.

Long Term Follow-up of Limbal Transplantation for Unilateral Chemical Injuries: 1997-2014

Purpose: To evaluate the long term results of limbal transplantation (LT) in patients with unilateral total limbal stem cell deficiency (LSCD) after chemical injury. Methods: The study includes 22 eyes of 22 consecutive patients (20 males and 2 females) who presented with total LSCD after unilateral chemical burns and underwent Limbal transplantation (LT) in the Cornea Service of the Department of Ophthalmology at the Heraklion University Hospital in Crete during the period from 1997 to 2014. All 22 cases underwent Conjunctival Limbal autogaft (CLAU) while in 14 surgeries it was combined with amniotic membrane transplantation (AMT). A second stage penetrating keratoplasty (PKP) was performed in 11 cases for visual rehabilitation. The healing time, the changes in VA and the stability of epithelial ocular surface integrity were looked for. Results: One case failed within 3 months of surgery, while the rest 21 eyes after CLAU maintained ocular surface epithelial integrity during the follow up period (7.8 ± 3.5 years), and showed improvement partially or totally in corneal neovascularization, symblepharon and ocular motility. The mean corneal healing time was 17 days, while visual acuity either showed statistically significant improvement in 18 eyes, with CLAU alone or followed by PKP. No significant difference in the surgical outcome was observed between AMT and none AMT cases. Conclusions: Conjunctival limbal autografts for limbal deficiency after unilateral chemical burn showed long term success and stability, in 21 out of 22 eyes, whether combined or not with amniotic membrane transplantation

Successful management of severe unilateral chemical burns in children using simple limbal epithelial transplantation (SLET)

AimTo study the outcomes of simple limbal epithelial transplantation (SLET) for unilateral total limbal stem cell deficiency (LSCD) secondary to severe ocular surface burns in children.MethodsRetrospective interventional case series was...

Single block conjunctival limbal autograft for unilateral total limbal stem cell deficiency

Journal of ophthalmic and Vision research 2015; Vol. 10, No. 1 Dear Editor, In the treatment of unilateral total limbal stem cell deficiency (LSCD), conjunctival limbal autograft (CLAU) surgery taken from the healthy fellow eye with or without amniotic membrane transplantation (AMT) is one of the main therapeutic alternatives.[1] There are some controversies regarding the optimal size of the limbal graft necessary for complete and stable epithelialization of the cornea.[2,3] Traditionally, two 60° limbal grafts have been used.[4] Few attempts have been made to reduce the overall size of the donor graft and it has been suggested that combining CLAU and AMT as a graft may minimize the required size of the limbal graft.[5] In a single case report, a group of authors noted that corneal epithelialization using one 60° block of CLAU was complete by day 18 after surgery.[5] They attributed this achievement to the use of amniotic membrane (AM) as a permanent graft underneath the CLAU and as a temporary patch over it. It has already been shown that in partial LSCD, one segment CLAU may suffice.[6] Rao et al successfully used one 60‐90° limbal block for treating eyes with partial LSCD. They found it insufficient to treat 2 other eyes with total LSCD.[7] Moldovan et al also found that one 90‐100° limbal block could restore eyes with total LSCD but that of 80° block surgery was unsuccessful.[8] In the present study, patients with total unilateral LSCD received a single 60° limbal block of CLAU, and we observed that the procedure was insufficient for stable and permanent ocular surface epithelialization by corneal phenotype epithelium. Medical charts of patients, who had received a single Single Block Conjunctival Limbal Autograft for Unilateral Total Limbal Stem Cell Deficiency

Postoperative Complications of Conjunctival Limbal Autograft Surgery

To report postoperative complications of conjunctival limbal autograft in patients with unilateral total limbal stem cell deficiency (LSCD). In this retrospective observational case series, medical charts of 34 patients with unilateral total LSCD with at least 6 months of follow-up were reviewed. Main outcome measure was postoperative complications. The mean follow-up period was 17.2 ± 6.3 (range, 6-33) months. The postoperative complications observed included conjunctival encroachment over the graft, small graft, graft dislodging, thick graft, improper position, graft edema, ocular surface exposure, progressive horizontal conjunctivalization, and pyogenic granuloma. Persistent epithelial defect occurred in 5 eyes because of ocular surface exposure (n = 2), conjunctival encroachment (n = 1), and small graft size (n = 2). Epithelial defects healed in 4 of them with sectoral vascularization of the cornea. Optical penetrating keratoplasty was performed on 18 eyes with dense corneal opacification. Persistent epithelial defect occurred in 6 eyes with inadvertent cut limbal graft (n = 2), small limbal graft (n = 2), and ocular surface exposure (n = 2). Conjunctival limbal autograft is an effective procedure for anatomical and visual rehabilitation of eyes with unilateral total LSCD. However, it may be complicated by several adverse events. The most common complications are related to the transplanted grafts (size, thickness, position, and alignment) and chronic ocular surface exposure, which may later lead to epithelial breakdown and corneal conjunctivalization.

Clinical outcomes of xeno-free autologous cultivated limbal epithelial transplantation: a 10-year study

PurposeOcular burns can damage the corneal epithelial stem cells located at the limbus. This study evaluated the efficacy of xeno-free autologous cell-based treatment of limbal stem cell deficiency.MethodsThis retrospective study...

Ex Vivo Cultured Limbal Epithelial Transplantation. A Clinical Perspective

The term ex vivo cultured limbal epithelial transplantation (CLET) refers to the process of culturing a sheet of human limbal epithelium in the laboratory and transplanting this sheet back onto the limbal stem cell-deficient cornea of the same patient or another recipient. This emerging technology represents one of the earliest successes in regenerative medicine. CLET is, at present, best suited to patients who have unilateral total limbal stem cell deficiency arising from chemical injury and who are suitable for autologous cell culture and transplantation. Although the results of allogeneic cell transplantation are encouraging and superior to conventional stem cell transplantation techniques, insufficient follow-up precludes conclusions regarding the long-term outcomes. Other tissues, such as oral mucosal epithelium, are emerging as viable alternative sources of cells, especially for patients with bilateral disease.

Thimerosal-Induced Limbal Stem Cell Failure: Report of a Case and Review of the Literature

To report a case of unilateral total limbal stem cell (LSC) failure and corneal opacification secondary to thimerosal- and contact lens-induced ocular surface toxicity. Interventional case report and review of the literature on thimerosal-induced ocular surface changes. A 49-year-old woman with a 2-year history of long-term soft contact lens wear developed unilateral total LSC failure and corneal opacification secondary to presumed thimerosal-induced toxicity and contact lens wear. At presentation, best-corrected visual acuities were 20/120 in the right eye and 20/15 in the left eye. The patient underwent a keratolimbal allograft and amniotic membrane graft followed by a penetrating keratoplasty. At the last follow-up, the right eye showed a clear corneal graft with a best-corrected visual acuity of 20/30. Thimerosal toxicity can lead to total LSC failure with secondary corneal vascularization and opacification. Keratolimbal allograft followed by penetrating keratoplasty can be successful in reconstructing the ocular surface in such cases.

Phenotypic study of a case with successful transplantation of ex vivo expanded human limbal epithelium for unilateral total limbal stem cell deficiency

ObjectiveTo minimize the risk to the donor eye when a conjunctival limbal autograft is performed for unilateral total limbal stem cell deficiency (LSCD), a new approach has been reported of expanding limbal epithelial progenitor cells from a small limbal biopsy cultured on amniotic membrane (AM). Herein, we present for the first time the morphologic and phenotypic outcome of one such patient. DesignInterventional case report. MethodsA 31-year-old male with a severe acid burn to his left eye received AM transplantation at the acute stage and a keratolimbal allograft (KLAL) at the chronic stage for total LSCD. As an alternative to combat the failed KLAL, the above-mentioned new surgical procedure was performed. The corneal button, obtained after a penetrating keratoplasty performed 5.5 months later, and a normal corneal button as a control were submitted to hematoxylin-eosin and immunofluorescence staining for keratin K3, connexin 43, goblet-cell mucin MUC 5AC, laminin 5, and integrins α3β1 and α6β4. Main outcome measuresClinical and immunohistologic features. ResultsThe resultant epithelium was stratified with five to six cell layers and anchored to laminin 5 of the amniotic basement membrane via integrins α3β1 and α6β4 in a manner similar to the normal corneal epithelium. Intriguingly, the epithelial phenotype was limbal and not corneal, based on the negative expression of keratin K3 and connexin 43 of the basal epithelium. ConclusionsThe technique described ensures the preservation of amniotic basement membrane, which allows formation of adhesion complexes and maintains normal corneal architecture. The preservation of a limbal epithelial phenotype on the reconstructed corneal surface indicates that AM provides a unique stromal environment conducive to the preservation and expansion of limbal epithelial progenitor cells.