Surgical Management of Unilateral Partial Limbal Stem Cell Deficiency: Conjunctival Autografts versus Simple Limbal Epithelial Transplantation

Ocular surface pseudoepitheliomatous hyperplasia secondary to allergic eye disease: clinical features and management

PURPOSE

To study the clinical characteristics and treatment outcomes of ocular surface pseudoepitheliomatous hyperplasia (PEH) associated with chronic vernal keratoconjunctivitis (VKC).

METHODS

This retrospective study includes 39 eyes of 32 patients with VKC induced PEH who presented from 2016-2022. A database search was conducted for diagnosis of PEH, and data on clinical features, imaging characteristics, and treatment were analyzed.

RESULTS

Of the 32 patients, 11 (34%) were children and adolescents, 21 (66%) were adults. PEH was common in males (72%) and ocular surface squamous neoplasia (OSSN) was the commonest referral diagnosis (43.7%). Mean age at presentation was 26.62 ± 10.18 (range: 6-52) years. While history of VKC was present in 21 patients, 11 were diagnosed with VKC at the time of diagnosis of PEH. The mean base/largest diameter was 5.2 ± 1.67 mm. Anterior segment optical coherence tomography (AS-OCT) showed irregular hyper-reflective epithelium, epithelial dipping, and sub-epithelial hyper-reflective lesion with shadowing in all lesions. Of the 31 eyes that received medical therapy, 21 (67%) and 10 (32%) eyes showed complete and partial resolution respectively with median time to resolution of 3(IQR:2-4) months. Eight eyes that underwent surgical excision showed complete resolution and one developed partial limbal stem cell deficiency.

CONCLUSION

Ocular surface PEH is a manifestation of chronic VKC which closely mimics OSSN. Detailed history-taking, examination for signs of allergy, and AS-OCT imaging can distinguish it from OSSN. It responds well to medical therapy and should be considered first-line therapy before planning any surgical intervention.

Safety and Efficacy of Contact Lenses in Eyes After Simple Limbal Epithelial Transplantation

PURPOSE

The aim of this study was to evaluate the safety and efficacy of contact lenses (CLs) in eyes after simple limbal epithelial transplantation (SLET) for limbal stem cell deficiency (LSCD).

METHODS

This retrospective study included 61 eyes with partial or total LSCD which underwent SLET and were fitted with corneal or scleral rigid gas-permeable CLs. The primary outcome measure was best-corrected visual acuity (BCVA) with CLs.

RESULTS

The median age at presentation was 22 years. The most common cause of LSCD was chemical injury [47/61 eyes (77%)]. Twenty-seven eyes (44%) were fitted with corneal rigid gas-permeable lenses, while 34 eyes (56%) were prescribed scleral lenses. The median duration of interval between SLET and CL trial was 10 months (interquartile range: 4-17). The median preoperative BCVA was logarithm of minimal angle of resolution (logMAR) 1.8. This improved to logMAR 1 ( P < 0.001) after SLET and to logMAR 0.6 ( P < 0.001) with CLs. Eyes with chemical injury (logMAR 1 vs. 0.6, P = 0.0001), grade 1 (logMAR 0.8 vs. 0.4, P < 0.0001), and grade 2 (logMAR 0.9 vs. 0.6, P = 0.004) corneal scarring had better improvement in BCVA with CLs. No complications were noted until the last follow-up visit.

CONCLUSIONS

CLs, both corneal and scleral lenses, provide significant visual improvement in eyes after SLET with residual corneal scarring. These can be safely prescribed in such eyes without any adverse effects. This option can be considered before offering keratoplasty in these eyes.

Comparison of mini-simple limbal epithelial transplantation and conjunctival-limbal autograft for the treatment of primary pterygium: a randomised controlled trial

PURPOSE

The purpose of this double-masked, parallel randomised controlled trial was to compare the recurrence rate and other outcomes between conjunctival-limbal autograft (CLAu) and mini-simple limbal epithelial transplantation (mini-SLET) after excision of pterygium.

METHODS

Eligibility criteria for participants was the presence of a primary nasal pterygium extending equally to or greater than two millimetres on the cornea on its horizontal axis from the nasal limbus. The participants were allocated into two groups (CLAu and mini-SLET) using simple randomisation with a table of random numbers. Participants and the outcome assessor were masked to the intervention. The study protocol is listed and available on https://clinicaltrials.gov (Identifier: NCT03363282).

RESULTS

A total of 61 eyes were enrolled in the study, 33 underwent CLAu (group 1) and 28 mini-SLET (group 2), all eyes were analysed in each group. At 2, 3, 6 and 12 months the CLAu group exhibited a recurrence of 0%, 6.1%, 8.1% and 8.1%, while the mini-SLET exhibited a recurrence of 0%, 17.9%, 50% and 53.5% (p<0.05). There were no intraoperative or postoperative complications in either of the two groups.

CONCLUSION

The findings of this study suggest that mini-SLET has a higher recurrence rate and provides no advantage over CLAu in the treatment of primary pterygium.

Sequelae of carbide-related thermo-chemical injury: A retrospective analysis

Purpose

To describe the outcomes of eyes with calcium carbide (CaC2)-related thermo-chemical injury.

Methods

This study included 28 eyes of 23 patients who presented with calcium carbide-related ocular burns. Only patients with more than three months of follow-up were included. Group A included 16 eyes with Dua's Grade I-III burns, while Group B included 12 eyes with Grade IV-VI burns. Electronic medical records were reviewed to provide data on the etiology of burn, presenting clinical signs and visual acuity, sequelae, and surgical interventions performed, both in the acute and chronic phases.

Results

The overall mean age was 28.48 ± 11.8 years. Fifteen patients were injured while using carbide to create an explosion to scare away animals on farms. The median presenting BCVA (best-corrected visual acuity) in Group A (20/160) was significantly better than in Group B [(20/2000) (P = 0.002)]. Five eyes in Group A and one eye in Group B underwent medical management. There was no difference in the duration of follow-up for both groups (P = 0.24). The median final BCVA in Group A (20/32) was significantly better than in Group B [(20/200) (P = 0.02)]. Two eyes in Group A and nine eyes in Group B developed LSCD. Two eyes in Group B were phthisical at the last visit.

Conclusion

Calcium carbide-related ocular injuries can result in significant visual morbidity in young adults. Early presentation and management may improve outcomes. Prevention of these injuries by increasing awareness and increasing advocacy efforts is necessary.

Enhanced adipose-derived stem cells with IGF-1-modified mRNA promote wound healing following corneal injury

The cornea serves as an important barrier structure to the eyeball and is vulnerable to injuries, which may lead to scarring and blindness if not treated promptly. To explore an effective treatment that could achieve multi-dimensional repair of the injured cornea, the study herein innovatively combined modified mRNA (modRNA) technologies with adipose-derived mesenchymal stem cells (ADSCs) therapy, and applied IGF-1 modRNA (modIGF1)-engineered ADSCs (ADSCmodIGF1) to alkali-burned corneas in mice. The therapeutic results showed that ADSCmodIGF1 treatment could achieve the most extensive recovery of corneal morphology and function when compared not only with simple ADSCs but also IGF-1 protein eyedrops, which was reflected by the healing of corneal epithelium and limbus, the inhibition of corneal stromal fibrosis, angiogenesis and lymphangiogenesis, and also the repair of corneal nerves. In vitro experiments further proved that ADSCmodIGF1 could more significantly promote the activity of trigeminal ganglion cells and maintain the stemness of limbal stem cells than simple ADSCs, which were also essential for reconstructing corneal homeostasis. Through a combinatorial treatment regimen of cell-based therapy with mRNA technology, this study highlighted comprehensive repair in the damaged cornea and showed the outstanding application prospect in the treatment of corneal injury.

The Multifold Etiologies of Limbal Stem Cell Deficiency: A Comprehensive Review on the Etiologies and Additional Treatment Options for Limbal Stem Cell Deficiency

Given the various ocular manifestations of limbal stem cell insufficiency, an awareness of the genetic, acquired, and immunological causes and associated additional treatments of limbal stem cell deficiency (LSCD) is essential for providers. We performed a comprehensive review of the literature on the various etiologies and specific therapies for LSCD. The resources utilized in this review included Medline (PubMed), Embase, and Google Scholar. All English-language articles and case reports published from November 1986 through to October 2022 were reviewed in this study. There were collectively 99 articles on these topics. No other exclusion criteria were applied. Depending on the etiology, ocular manifestations of limbal stem cell deficiency range from dry eye syndrome and redness to more severe outcomes, including corneal ulceration, ocular surface failure, and vision loss. Identifying the source of damage for LSCD is critical in the treatment process, given that therapy may extend beyond the scope of the standard protocol, including artificial tears, refractive surgery, and allogeneic stem cell transplants. This comprehensive review of the literature demonstrates the various genetic, acquired, and immunological causes of LSCD and the spectrum of supplemental therapies available.

A Review of the Diagnosis and Treatment of Limbal Stem Cell Deficiency

Limbal stem cell deficiency (LSCD) can cause significant corneal vascularization and scarring and often results in serious visual morbidity. An early and accurate diagnosis can help prevent the same with a timely and appropriate intervention. This review aims to provide an understanding of the different diagnostic tools and presents an algorithmic approach to the management based on a comprehensive clinical examination. Although the diagnosis of LSCD usually relies on the clinical findings, they can be subjective and non-specific. In such cases, using an investigative modality offers an objective method of confirming the diagnosis. Several diagnostic tools have been described in literature, each having its own advantages and limitations. Impression cytology and in vivo confocal microscopy (IVCM) aid in the diagnosis of LSCD by detecting the presence of goblet cells. With immunohistochemistry, impression cytology can help in confirming the corneal or conjunctival source of epithelium. Both IVCM and anterior segment optical coherence tomography can help supplement the diagnosis of LSCD by characterizing the corneal and limbal epithelial changes. Once the diagnosis is established, one of various surgical techniques can be adopted for the treatment of LSCD. These surgeries aim to provide a new source of corneal epithelial stem cells and help in restoring the stability of the ocular surface. The choice of procedure depends on several factors including the involvement of the ocular adnexa, presence of systemic co-morbidities, status of the fellow eye and the comfort level of the surgeon. In LSCD with wet ocular surfaces, autologous and allogeneic limbal stem cell transplantation is preferred in unilateral and bilateral cases, respectively. Another approach in bilateral LSCD with wet ocular surfaces is the use of an autologous stem cell source of a different epithelial lineage, like oral or nasal mucosa. In eyes with bilateral LSCD with significant adnexal issues, a keratoprosthesis is the only viable option. This review provides an overview on the diagnosis and treatment of LSCD, which will help the clinician choose the best option amongst all the therapeutic modalities currently available and gives a clinical perspective on customizing the treatment for each individual case.

Allogeneic simple limbal epithelial transplantation for bilateral limbal stem cell deficiency in chronic vernal keratoconjunctivitis: A case report

Introduction and importance

This report describes the management of bilateral limbal stem cell deficiency (LSCD) in vernal keratoconjunctivitis (VKC) with allogeneic simple limbal epithelial transplantation (allo-SLET).

Presentation of case

A 22-year-old female presented with bilateral VKC with total LSCD. A thick fibrotic pannus was present in both eyes, with visual axis involvement in the right eye. The central cornea in the left eye was clear. The patient underwent a cadaveric allo-SLET in the right eye to restore the ocular surface. Systemic immunosuppression with oral cyclosporine was administered following the surgery. The corrected visual acuity with scleral contact lenses (SCL) was 20/20 in both eyes which was maintained until the last follow-up visit, one year after the surgery. No recurrence of LSCD was observed in the right eye and the ocular surface was well epithelialized.

Discussion

Allo-SLET is a simple and efficacious surgical technique for bilateral LSCD. Eyes with VKC have a wet ocular surface, relatively clear corneal stroma, and minimal adnexal involvement. Thus, allo-SLET is the ideal procedure to address LSCD in such cases. The systemic immunosuppression that is given for ensuring graft survival can also help control the underlying allergy. Scleral contact lenses improve the visual acuity and their long-term usage does not affect the functioning of the SLET transplants.

Conclusion

VKC with bilateral LSCD can be successfully managed with allogeneic SLET. Post-operative systemic immunosuppressants are essential to maintain viable grafts. The use of SCL can improve vision and they do not pose any risk to the SLET transplants.

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Bilateral total limbal stem cell deficiency requires allogeneic stem cell transplant.

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Systemic immunosuppression is essential to maintain viable grafts in allo-SLET.

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In ocular allergy, these medications also help control the underlying inflammation.

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Scleral lenses can optimize the visual outcomes after allogeneic SLET.

Management of Symblepharon Prior to Keratoprosthesis in Chronic Ocular Burns: A Sequential Approach

This report describes two cases with stepwise management of chronic ocular burn sequelae with concurrent total limbal stem cell deficiency (LSCD) and advanced symblepharon. Both were mono-ocular patients with the other eye being phthisical. In both cases, a sequential approach was planned, and at the first stage, the symblepharon was released to stabilize the ocular surface and form the fornices. This was followed by a type 1 keratoprosthesis (KPro) after four months of symblepharon release in the first case, and after nine months in the second case. In the first case, after symblepharon release, the resultant bare sclera was addressed with an oral mucous membrane graft (MMG). Over two years of follow-up, there was no evidence of recurrence of the symblepharon. No further surgical interventions were required. In the second case, after symblepharon release, the resultant bare sclera was addressed with a cryopreserved amniotic membrane (AM). Over eight years of follow-up, six episodes of recurrence of the symblepharon were noted over the optic of the KPro, necessitating trimming of the conjunctiva from over the optic. Thus, with these two cases, we would like to emphasize that addressing adnexal pathologies such as a symblepharon with an oral MMG before implanting a KPro, may help prevent further recurrences of symblephara and the need for multiple surgical interventions. The oral mucosa is a better alternative to the conjunctiva as compared to the AM in a mono-ocular patient where conjunctiva cannot be harvested from the contralateral eye.

Conjunctival Autograft for Tarsal Keratinization in a Case of Chronic Vernal Keratoconjunctivitis

This report describes the clinical features and management in a case of vernal keratoconjunctivitis (VKC) with bilateral tarsal conjunctival keratinization. A 32-year-old male presented with VKC since childhood that had exacerbated in the eight years prior to presentation. Examination revealed partial limbal stem cell deficiency in both eyes, with keratinization of the superior tarsal conjunctiva. The corresponding areas of the cornea exhibited punctate keratopathy in both eyes. To address this, the patient underwent excision of the conjunctival keratinization in both eyes. The resultant bare areas were covered with conjunctival autografts (CAGs). Postoperatively, the grafts were well apposed, and there was no recurrence of keratinization observed during the period of follow-up of four years. Resolution of corneal epitheliopathy was also noted. Although keratinization can occur in eyes with VKC, it is usually limited to the bulbar conjunctival areas. This is the first report of tarsal conjunctival keratinization in such cases. Milder cases may be observed or managed with scleral contact lenses. In more severe forms, there is associated corneal epitheliopathy, which may progress to corneal vascularization and scarring. Surgical excision of the lesion is recommended in these eyes. Following excision, several options exist to cover the bare area, which include a CAG, an amniotic membrane, or an oral mucous membrane. Of these, a CAG is an autologous tissue that can be harvested with a simple surgical technique and yields stable long-term results. Thus, tarsal conjunctival keratinization is a rare complication of chronic VKC. Excision of the lesion followed by a CAG is a viable approach for treatment, which reestablishes and maintains a stable ocular surface.