Amniotic membrane transplantation in the management of conjunctival malignant melanoma and primary acquired melanosis with atypia

Amniotic membrane application in surgical treatment of conjunctival tumors

The amniotic membrane (AM) has special properties, making it ideal for clinical applications in various surgical fields like ophthalmology. It is used more frequently to cover conjunctival and corneal defects. In our retrospective study we have been combined 68 patients with epibulbar conjunctival tumors they have been surgically treated in the period of 2011-2021. Seven (10.3%) patients have been treated with AM application after surgical removal of the tumor. 54 (79%) cases were malignant, and 14 (21%) were benign. In the analyzed dataset the males had just slightly higher chance of malignancy than females, 80% versus 78.3%. For the significancy calculation the Fisher exact test was used and the result proved no significancy (p = 0.99). Six patients with AM application were malignant. The observed difference in the number of quadrants of the bulbar conjunctiva infiltrated versus significant malignancy with p = 0.050 calculated by Fisher Exact test and with p = 0.023 calculated by Likelihood-ratio test. The results of our study indicate that AM grafts are an effective alternative to cover defects after removal of epibulbar lesions due to their anti-inflammatory properties because the conjunctiva must be preserved, and especially the most important application is in malignant epibulbar conjunctival tumors.

Small but Challenging Conjunctival Melanoma: New Insights, Paradigms and Future Perspectives

Although its incidence has increased over the last decades, conjunctival melanoma (CM) remains a rare but challenging periocular malignancy. While there is currently no recognized standard of care, "no-touch" surgical excision followed by adjuvant treatments is usually recommended. Despite its small size, managing CM is challenging for clinicians. The first challenge is the high risk of tumour local recurrence that occurs in about one third of the patients. The management of locally advanced CM (≥T2) or multiple recurrences may require mutilating surgeries such as orbital exenteration (OE). The second challenge is the metastatic spread of CM that occurs in about one quarter of patients, regardless of whether complete surgical excision is performed or not. This highlights the infiltrative and highly aggressive behaviour of CM. Recently, attention has been directed towards the use of eye-sparing strategies to avoid OE. Initially, wide conservative surgeries followed by customized brachytherapy or radiotherapy have appeared as viable strategies. Nowadays, new biological insights into CM have revealed similarities with cutaneous melanoma. These new findings have allowed clinicians to reconsider the management of locally advanced CM with "medical" eye-sparing treatment as well as the management of metastatic spread. The aim of this review was to summarize the current and future perspectives of treatment for CM based on recent biological findings.

Surgical alternatives to keratoplasty in microbial keratitis

Penetrating keratoplasty is often required in microbial keratitis not responding to the standard treatments available or the development of complications like corneal perforation. Performing keratoplasty in microbial keratitis has several challenges, the major ones being the availability of donor corneal tissue and the poor success of the corneal graft performed in such a setting. For overcoming these challenges, several alternatives to keratoplasty have been described. Broadly, these options could be categorized into autologous tissues such as conjunctival and tenon tissue, synthetic products like tissue adhesives and therapeutic contact lenses, or biological tissues like amniotic membrane graft. These alternative modalities are not universal. They have their specific indications in microbial keratitis. Most of these alternatives are useful only for small corneal perforations. While autologous tissues are cost-effective and readily available, lack of tectonic support is a significant limitation. Tissue adhesives are excellent alternatives in terms of tectonic support, but surface irregularity and tissue reaction are their potential limitations. The amniotic membrane is useful for small corneal perforations, but availability, cost, and poor tectonic support restrict its use. Herein, we discuss these various alternatives to keratoplasty in microbial keratitis, their indications, advantages, disadvantages, and the various techniques of performing these procedures.

Amniotic Membrane Transplantation in Ophthalmology: An Updated Perspective

Aim

The aim of this paper is to provide a succinct literature review of the different clinical applications for AMT usage in an ophthalmic setting, ranging from commonly used applications to less mainstream approaches. The hope is that this review enables the reader to have a better understanding of the biological properties of amnion as well as the indications and scenarios in which AMT can be used, whilst presenting relevant evidence from within the literature which may be of interest. We also provide an update on the methods of preservation of amniotic membrane and the application methodologies.

Methods

Literature search. A PubMed search was performed using the search terms “amniotic membrane transplant”, “amnion AND cornea”, amnion AND ophthalmology”, “amnion AND ocular surface” and “Amnion AND eye”. A full review of the literature using the PubMed database was conducted up until 01/05/20. The articles used were written in English, with all articles accessed in full. Both review articles and original articles were used for this review. All full publications related to ophthalmology were considered.

Effect of Amniotic Membrane Dressing on Pain and Healing of Palatal Donor Site: A Randomized Controlled Trial

BACKGROUND

Free gingival graft is the most commonly practiced predictable technique for gingival augmentation.

OBJECTIVE

To assess the effectiveness of human amniotic membrane, a biological dressing, on wound healing and post-operative pain after its application on the palatal donor site after free gingival graft surgery.

METHODS

Of 27 eligible patients, 15 were randomized into a test group and received human amniotic membrane dressing sutured over their palatal donor site; 12 were randomized into a control group in whom the palatal donor site was only sutured. Standard clinical photographs were taken at 7, 14, and 21 days post-operatively and evaluated by 3 periodontists. The pain score at the donor site was assessed by a visual analog score; the number of analgesics taken was also recorded.

RESULTS

The mean color match scores were higher in the test group than the control group at 14 (p<0.01) and 21 days after surgery (p=0.02). The difference in tissue texture (p=0.01) and inflammation (p=0.02) between the two groups was only significant on day 14 (p<0.05). The pattern of pain relief was better in the test group compared with the control group, especially in first days, although the differences were not significant in terms of the number of analgesics taken or the pain score.

CONCLUSION

Application of human amniotic membrane can accelerate wound healing and may decrease post-operative pain and discomfort by a limited amount.

Tumors of the conjunctiva and cornea

Tumors of the conjunctiva and cornea comprise a large and varied spectrum of conditions. These tumors are grouped into two major categories of congenital and acquired lesions. The acquired lesions are further subdivided based on origin of the mass into surface epithelial, melanocytic, vascular, fibrous, neural, histiocytic, myxoid, myogenic, lipomatous, lymphoid, leukemic, metastatic and secondary tumors. Melanocytic lesions include nevus, racial melanosis, primary acquired melanosis, melanoma, and other ocular surface conditions like ocular melanocytosis and secondary pigmentary deposition. The most frequent nonmelanocytic neoplastic lesions include squamous cell carcinoma and lymphoma, both of which have typical features appreciated on clinical examination. The caruncle displays a slightly different array of tumors compared to those elsewhere on the conjunctiva, as nevus and papilloma are most common, but oncocytoma and sebaceous gland hyperplasia, adenoma, and carcinoma can be found. In this report, we provide clinical description and illustration of the many conjunctival and corneal tumors and we discuss tumor management.

Super-Thick Amniotic Membrane Graft for Ocular Surface Reconstruction

PURPOSE

The purpose of this study was to evaluate super-thick amniotic membrane grafts (ST-AMGs) for ocular surface reconstruction.

DESIGN

Retrospective, interventional case series.

METHODS

This was a single-center study of clinical practice that included select patients with typically large ocular surface abnormalities that required reconstruction. The intervention studied was surgical insertion of a ST-AMG for reconstruction or repair of the ocular surface. Main outcome measures included intraoperative handling, graft position at 1 week post implantation, graft dissolution at 3 weeks, epithelialization of the ocular surface and symblepharon.

RESULTS

Eleven ST-AMGs were implanted after resection with cryotherapy: 5 conjunctival melanoma, 4 squamous cell carcinoma, 1 sebaceous carcinoma, and 1 atypical pterygium. In addition, 1 was implanted for scleral necrosis. ST-AMGs were up to nine times thicker than standard amniotic grafts and were therefore amenable to both running and interrupted 7-0 Vicryl sutures without cheese-wiring. All cases had a well-positioned ST-AMG at 1 week and 75% (n = 9) had partial graft dissolution at 3 weeks. Complete epithelialization without wound dehiscence was noted in all cases. However, secondary (after additional tumor treatment) symblepharon formed in 16.7% (n = 2). In all cases, the mean visual acuity and intraocular pressures remained unchanged during conjunctival reconstruction and subsequent secondary treatments. Post epithelialization adjuvant topical chemotherapy was given to extend treatment margins and treat presumed occult disease in 50% (n = 6). At mean follow-up of 25.5 months (median 10, range 3-90), 10 cases (83.3%) showed complete local tumor control, 1 showed revascularization of the scleral melt, and 1 required orbital exenteration.

CONCLUSION

ST-AMGs were easy to suture and relatively persistent. Epithelialization of the ocular surface without primary symblepharon formation was noted. ST-AMGs should be considered an alternative for ocular surface reconstruction.

Surgical management of a conjunctival nevus with amniotic membrane transplantation

Purpose

Nevi of the conjunctiva are usually benign pigmented tumorous lesions located in the bulbar conjunctiva. In most conjunctival nevus cases, the patient wants the lesion to be removed for cosmetic reasons, but excisional biopsies are best for lesions suspicious for malignancy. This case report illustrates the intraoperative surgical management, histological findings, and the course of healing in a conjunctival nevus patient.

Case report

A 26-year-old man was referred to our eye hospital with a large bulbar conjunctival nevus of the right eye. Upon examination, there was a large pigmented lesion with numerous small cysts present on the superior bulbar conjunctiva. The conjunctival tumor was resected, and an amniotic membrane transplantation was performed for the bulbar conjunctival reconstruction. The histopathological diagnosis suggested a conjunctival nevus. After the resection, a reduction in the inflammation and healing of the conjunctival lesion could be seen. The epithelialization of the bulbar conjunctiva over the amniotic membrane was complete 4 weeks after the resection. At the 6-month follow-up, there was no sign of recurrence or any postoperative complications.

Conclusion

A surgical excision combined with reconstruction via amniotic membrane transplantation is effective and economical for the treatment of large conjunctival lesions.

Amniotic Membrane Transplantation in Reconstructive and Regenerative Ophthalmology

Background

The goal of this study was to investigate numbers, indications, surgical techniques, and experiences of amniotic membrane transplantation at the University Eye Hospital Tübingen over the last 16 years.

Material/Methods

Data from all amniotic membrane transplantations from January 2001 to December 2016 were retrospectively analyzed. Data was accessed from the electronic database and the annual reports of the Eye Bank at the University Eye Hospital Tübingen.

Results

A total of 771 amniotic membrane transplantations were performed between 2001 and 2016 at the University Eye Hospital Tübingen. The mean number of amniotic membrane transplantations was 48 per year (range: 7–81). Overall, the mean number of amniotic membrane transplantations more than doubled, from 31 amniotic membrane transplantations per year during the first 8-year period to 66 amniotic membrane transplantations per year during the second 8-year period (p<0.0001). The most common surgical indications for amniotic membrane transplantation were corneal ulcers and persistent corneal epithelial defects. The inlay, overlay, and sandwich technique became the favored surgical methods for various disorders of the ocular surface.

Conclusions

Our study showed a significant increase of amniotic membrane transplantations from 2001 to 2016. This increase is likely influenced by the introduction of different surgical amniotic membrane transplantation techniques, the rising knowledge about containing growth factors, neurotrophins and cytokines, and the demographic change with aging of the population.

Reconstruction of Conjunctiva with Amniotic Membrane after Excision of Large Conjunctival Melanoma: A Long-Term Study

Purpose

To evaluate, on a long- term basis, the role of amniotic membrane in the reconstruction of large conjunctival defects after excision of large conjunctival melanoma.

Methods

Four consecutive patients with diffuse conjunctival melanoma involving both bulbar and palpebral conjunctiva were studied. Conjunctival melanoma was completely excised (with wide clinically disease-free margins) and amniotic membrane immediately sutured to the surrounding conjunctiva and sclera to cover the conjunctival defect. Minimum follow-up was 48 months.

Results

Successful conjunctival surface reconstruction and physiologic fornical depth were achieved in all patients within 6 weeks. No recurrence of primary melanoma was observed during long-term follow-up.

Conclusions

Amniotic membrane transplantation is an effective alternative in ocular surface repairing surgery after removal of large conjunctival tumors.

New Therapeutic Perceptions in a Patient with Complicated Herpes Simplex Virus 1 Keratitis: A Case Report and Review of the Literature

Patient: Male, 80

Final Diagnosis: Unilateral complicated Herpetic Simplex Virus 1 Keratitis

Symptoms: Visual impairment

Medication: Anti-herpetic treatment • Anti-VEGF • Cyclosporine A • Matrix regeneration therapy

Clinical Procedure: Amniotic membrane and limbal stem cell transplantation

Specialty: Ophthalmology

Management of a neurotrophic deep corneal ulcer with amniotic membrane transplantation in a patient with functional monocular vision: A case report

RATIONALE

Amniotic membrane transplantation (AMT) has been performed therapeutically in humans for over 100 years. In recent 2 decades AMTs have been used increasingly and successfully to treat various types of ophthalmic indications.

PATIENT CONCERNS

An 83-year-old man was referred to our eye hospital with a refractory neurotrophic deep corneal ulcer of the left eye.

DIAGNOSES

The best-corrected visual acuity of the left eye was 0.5 (0.3 logMAR) and of the right eye was 0.05 (1.3 logMAR), which was caused by a central retinal vein occlusion 5 years previously. In cases of binocular vision, a large amniotic membrane patch can cover the whole cornea, including the optical axis. However, in cases with functional monocular vision, as in the case reported here, the AMT has to be performed without the involvement of the optical axis to ensure vision for the patient. Otherwise the patient would have a massively restricted view like looking through waxed paper for at least 2-4 weeks until the overlay dissolved.

INTERVENTIONS

For this case, an AMT using a modified sandwich technique was applied without involvement of the optic axis to ensure vision for the patient. This case report illustrates this eye's course of healing over time.

OUTCOMES

A reduction in the inflammation and healing of the corneal ulcer could be seen. In addition, the corneal vascularization decreased. Six months after the AMT, a slit-lamp examination revealed stable findings. The best-corrected visual acuity of the left eye had increased to 0.8 (0.1 logMAR).

LESSONS

To the best of our knowledge, a case report on the management of a neurotrophic deep corneal ulcer with AMT in a patient with functional monocular vision has never been undertaken before.

Fresh frozen amniotic membrane for conjunctival reconstruction after excision of neoplastic and presumed neoplastic conjunctival lesions

PurposeSuspicious neoplastic conjunctival lesions often require wide excision with tumour-free margins, leaving significant conjunctival defects requiring reconstruction. In this study we report the results of using fresh frozen amniotic membrane grafts (AMG) after wide excision of potentially malignant lesions.MethodsRetrospective review of 53 patients; between January 2011 and April 2014. Conjunctival lesions were excised with a non-touch technique (2 mm margin) and sent for histopathological analysis. The surgical margins were treated with cryotherapy and a fresh frozen AMG was used to cover the defect. The main features examined were for any signs of recurrence, the conjunctivalisation of the AMG, complications and cosmetic appearance.ResultsFifty-three patients; 35 males and 18 females. Mean age was 54.9 (range 19-88). The mean follow up to January 2015 for all lesions was 21.4 months (range 8-48 months). The most common lesions were invasive malignant melanoma. There were no local surgical complications in 77.3% of patients; minimal scarring (11.3%), symblepharon (11.3%), and granuloma (7.5%). Five patients with conjunctival melanoma developed in-transit metastasis and orbital extension, none of it was at the site of the AMG.ConclusionOur case series is the largest reported to date, with the largest number of melanomas. The use of fresh frozen AMG has improved the local surgical outcomes by improving healing and reducing scarring as well as allowing for a wider surgical margin.

Clinical comparison of coronally-advanced flap plus amniotic membrane or subepithelial connective tissue in the treatment of Miller's class I and II gingival recessions: A split-mouth study

Background. The aim of the present study was to compare coronally advanced flap (CAF) plus amniotic membrane (AM) to CAF with connective tissue graft (CTG) in the treatment of Miller’s class I and II gingival recessions.

Methods. Eleven healthy subjects with thirty Miller’s class І and ІІ gingival recessions ≥3 mm, were selevted for this research and randomly assigned to two groups in a split-mouth design. In the control group gingival recessions were treated with CAF and CTG; however, in the test group the lesions were treated with (AM) and CAF. The clinical parameters, including recession depth (RD), recession width (RW), keratinized tissue width (WKT), probing depth (PD) and clinical attachment level (CAL), were measured at baseline and 1, 3 and 6 months postoperatively. Statistical significance was set at P < 0.01.

Results. Position changes of RD, RW, CAL, and MGJ were significant between baseline and one month after surgery (P < 0.01) in both the test and control groups and these values remained unchanged at 3- and 6-month follow-ups. There were no statistically significant differences in PD and WKT between baseline and 1-, 3- and 6-months intervals postoperatively. The mean root coverage values after 6 months were 75.5% and 63.1% for two groups, respectively. The mean recession depth reductions were 2.63±0.63 mm and 2±1.4 mm in the test and control groups, respectively.

Conclusion. The results of this research showed that application of AM instead of connective tissue decreased surgical operation time and patient discomfort but the amount of root coverage was not significantly different between the two methods.

Human amniotic membrane transplantation: Different modalities of its use in ophthalmology

The amniotic membrane (AM) is the inner layer of the fetal membranes and consist of 3 different layers: the epithelium, basement membrane and stroma which further consists of three contiguous but distinct layers: the inner compact layer, middle fibroblast layer and the outermost spongy layer. The AM has been shown to have anti-inflammatory, anti-fibrotic, anti-angiogenic as well as anti-microbial properties. Also because of its transparent structure, lack of immunogenicity and the ability to provide an excellent substrate for growth, migration and adhesion of epithelial corneal and conjunctival cells, it is being used increasingly for ocular surface reconstruction in a variety of ocular pathologies including corneal disorders associated with limbal stem cell deficiency, surgeries for conjunctival reconstruction, as a carrier for ex vivo expansion of limbal epithelial cells, glaucoma surgeries and sceral melts and perforations. However indiscriminate use of human AM needs to be discouraged as complications though infrequent can occur. These include risk of transmission of bacterial, viral or fungal infections to the recipient if the donors are not adequately screened for communicable diseases, if the membrane is not processed under sterile conditions or if storage is improper. Optimal outcomes can be achieved only with meticulous case selection. This review explores the ever expanding ophthalmological indications for the use of human AM.

Management of conjunctival malignant melanoma: a review and update

Conjunctival malignant melanoma is a pigmented lesion of the ocular surface. It is an uncommon but potentially devastating tumor that may invade the local tissues of the eye, spread systemically through lymphatic drainage and hematogenous spread, and recur in spite of treatment. Despite its severity, the rarity of available cases has limited the evidence for diagnosis and management. This review will provide an overview of the epidemiology, presentation, diagnosis, management, and surveillance of conjunctival melanoma, with an emphasis on recent advances in biological therapies to treat this disease.

Update on amniotic membrane transplantation

Cryopreserved amniotic membrane modulates adult wound healing by promoting epithelialization while suppressing stromal inflammation, angiogenesis and scarring. Such clinical efficacies of amniotic membrane transplantation have been reported in several hundred publications for a wide spectrum of ophthalmic indications. The success of the aforementioned therapeutic actions prompts investigators to use amniotic membrane as a surrogate niche to achieve ex vivo expansion of ocular surface epithelial progenitor cells. Further investigation into the molecular mechanism whereby amniotic membrane exerts its actions will undoubtedly reveal additional applications in the burgeoning field of regenerative medicine. This article will focus on recent advances in amniotic membrane transplantation and expand to cover its clinical uses beyond the ocular surface.

Preparation, indications and results of human amniotic membrane transplantation for ocular surface disorders

In comparison with other biologic tissues used as reconstructive grafts, the amniotic membrane has the advantage that it is thinner and better tolerated by the patient. Amniotic membrane, when appropriately preserved, can be used as a substrate replacement, such that host cells can migrate into the membrane to form new and healthy tissue. The amniotic membrane is the deeper layer of the fetal membrane; it is avascular, multilayered tissue with antiangiogenic, antiscarring and anti-inflammatory properties. Since it does not express antigens of histocompatibility, the membrane is never rejected by the receiving tissues. In addition, the beneficial effects of reducing inflammation and neovascularization persist for a long time, if properly cryopreserved.

Conjunctival melanoma and melanocytic intra-epithelial neoplasia

The rarity of conjunctival melanoma has impeded progress in the management of patients with this cancer; however, much progress has occurred in recent years. Primary acquired melanosis is now differentiated histologically into hypermelanosis and conjunctival melanocytic intra-epithelial neoplasia, for which an objective reproducible scoring system has been developed. Mapping and clinical staging of conjunctival disease has improved. Adjunctive radiotherapy and topical chemotherapy have made tumour control more successful, with reduced morbidity. Genetic analyses have identified BRAF and other mutations, which may predict responsiveness to new chemotherapeutic agents, for example Vemurafenib, should metastatic disease develop. Multicentre studies are under way to enhance survival prediction by integrating clinical stage of disease with histological grade of malignancy and genetic abnormalities. Such improved prognostication would not only be more relevant to individual patients, but would also provide greater opportunities for basic science research.

Excision with corneoscleral lamellar keratoplasty and amniotic membrane transplantation of a corneal displaced recurrent conjunctival melanoma

An 81-year-old woman with a raised pigmented nodule over her left cornea for 7 months duration was examined. Dark conjunctival pigmentation was observed in the upper bulbar fornix conjunctiva. She had previously undergone primary surgical excision of a malignant conjunctival melanoma four years earlier. The tumor separated easily from the corneal surface, but remained slightly attached to the corneoscleral surface. A corneoscleral lamellar dissection of 3 mm in width and 2 mm in depth as well as a corneoscleral lamellar keratoplasty for the reconstruction of the corneoscleral defect were performed. The wide upper bulbar and fornix conjunctiva were excised, and an amniotic membrane transplantation was performed. Biopsy revealed an invasive melanoma with a depth of 1 mm. Left, right, and inferior tumor margins of the corneoscleral lesion and the pigmentary lesion in the conjunctiva were free of the tumor. After surgery, 0.04% mitomycin was administered topically 4 times daily for 4 weeks. There was no recurrence 2 years after surgery, and systemic evaluation revealed no metastasis.

Management of pigmented conjunctival lesions

Pigmented conjunctival lesions primarily include melanoma, nevus, primary acquired melanosis (PAM), and complexion-associated melanosis. The incidence of conjunctival malignant melanoma (CMM) has significantly increased in the USA and Europe over the years, and it carries a very serious risk for metastasis and melanoma-related death. Conjunctival melanoma can arise de novo or from precursor lesions, nevus, and PAM. PAM is histologically separated into two distinct forms: PAM with atypia and without atypia. PAM with severe atypia progresses to malignant melanoma in up to 50% of cases and PAM without atypia virtually never progresses. Nevus is a benign melanocytic tumor that only rarely undergoes malignant transformation. Complexion-associated melanosis is frequently seen in more darkly pigmented individuals and does not progress to melanoma, although it can become very large. A detailed literature review on the various pigmented conjunctival lesions together with a schematic approach to diagnosis and management is presented.

Ocular surface reconstruction using amniotic membrane following excision of conjunctival and limbal tumors

PURPOSE

To report the clinical results of patients treated by preserved human amniotic membrane transplantation (AMT) following the removal of conjunctival and limbal tumors.

METHODS

Retrospective noncomparative interventional case series of 9 patients (9 eyes) who underwent AMT after removal of conjunctival and limbal tumors with lesion-free margins and perilesional cryotherapy.

RESULTS

The excised tumors were histopathologically examined and included 2 squamous cell carcinomas, 2 papillomas, and 5 nevi. Bulbar conjunctiva was involved in all of the eyes, limbus and cornea in 7 and 3 eyes, respectively. The mean extent of the limbal involvement was 4 clock hours (range 2-9, SD 2.4); the average diameter of the base of the tumor was 12.8 mm (range 10-20, SD 4.4). The mean follow-up time was 38 months (range 13-60, SD 15). No surgical or early postoperative complications were observed. In all eyes, complete healing of the tissue defect occurred, resulting in a stable, wet, and noninflamed epithelium. All eyes demonstrated a smooth ocular surface except one with a clinically insignificant symblepharon after the excision of a squamous cell carcinoma. Superficial peripheral corneal vascularization and opacification as a sign of partial limbal stem cell deficiency developed in 2 eyes. In one case, a recurrence of conjunctival papilloma was diagnosed after a 3-year follow-up.

CONCLUSIONS

Amniotic membrane transplantation is an effective method of reconstruction following a conjunctival and limbal tumor excision and cryotherapy of surgical wound margins. In most cases, complete healing of an ocular surface can be achieved without any clinically significant complications.

The effects of different preservation processes on the total protein and growth factor content in a new biological product developed from human amniotic membrane

The aim of this work is to quantify the total protein and growth factors content in a tissue-suspension obtained from processed human amniotic membrane (hAM). hAM was collected, frozen, freeze dried, powdered and sterilized by γ-irradiation. At each step of the process, samples were characterized for the total protein amounts by a Bradford protein assay and for the growth factor concentrations by ELISA test of the tissue suspensions. Frozen-hAM samples show higher release of total proteins and specific growth factors in the tissue suspension in comparison with freeze-dried hAM. We observed that even if the protein extraction is hindered once the tissue is dried, the powdering process allows a greater release in the tissue suspension of total proteins and growth factors after tissue re-solubilization in comparison with only the freeze-drying process (+91 ± 13% for EGF, +16 ± 4% for HGF, +11 ± 5% for FGF, +16 ± 9% for TGF-β1), and a greater release of EGF (85 ± 10%) in comparison with only the freezing process, because proteins become much readily solubilized in the solution. According with these results, we describe a protocol to obtain a new sterile biological product from hAM tissue, with well-known effects of thermal, mechanical and physical processes on the total protein and grow factors contents.

Amniotic membrane transplantation in the human eye

BACKGROUND

Amniotic membrane transplantation (AMT) has a long tradition in ophthalmic surgery and has become very popular recently because of newly developed methods of tissue preservation.

METHODS

We selectively review the literature on recent developments, mechanisms of action, and established indications of AMT in the treatment of various diseases of the ocular surface. We searched the PubMed database for articles that appeared from 1994 to 2009 with the key words "amniotic membrane," "cornea," and/or "conjunctiva."

RESULTS

Amniotic membrane (AM) can function in the eye as a basement membrane substitute or as a temporary graft. It has anti-inflammatory and anti-scarring effects and contains growth factors that promote epithelial wound healing on the surface of the eye. AMT has been found to be a good alternative for corneal and conjunctival reconstruction in many clinical situations, including acute burns, persistent epithelial defects of the cornea, and diseases that cause conjunctival scarring. Nonetheless, there have been no more than a few randomized and controlled trials of AMT to date. Other studies have shown that AM can serve as a culture substrate to expand epithelial progenitor cells for use in ocular surface reconstruction.

CONCLUSION

AMT is an established technique in the treatment of various diseases of the external eye. In the last few years, AMT has brought about major advances in the reconstructive surgery of the ocular surface.

Amniotic membrane in medial canthal reconstruction

PURPOSE

To describe the use of amniotic membrane for reconstruction of large medial canthal defects.

METHODS

Four cases of medial canthus resection of cutaneous malignancies were reconstructed using amniotic membrane to cover exposed sclera and orbital fat, combined with other reconstructive techniques including titanium plating and myocutaneous flaps.

RESULTS

Complete epithelialization of the scleral defect covered with amniotic membrane was seen within 6 weeks in all 4 patients.

CONCLUSIONS

Amniotic membrane is useful for complex reconstructions of the medial canthus, and can be combined with other techniques such as myocutaneous flaps. This technique results in good functional and cosmetic results.

Tissue engineering for conjunctival reconstruction: established methods and future outlooks

Reconstruction of the conjunctiva is an essential part of ocular surface regeneration, especially if an extensive area or the whole ocular surface is affected, such as in patients with ocular cicatricial pemphigoid, Stevens-Johnson syndrome, toxic epidermal necrolysis, or chemical/thermal burns. In these situations, corneal reconstruction almost inevitably fails unless the conjunctival surface is first repaired and a deep fornix is restored. The growing field of tissue engineering and advances in stem cell research offer promising new alternatives for these challenges. This article reviews the present approaches for reconstruction of the conjunctival surface, considering the established strategies and new potential methodologies.

Homogenous amniotic membrane as a biological dressing for oral mucositis in rats: histomorphometric analysis

OBJECTIVE

Oral mucositis is a frequent and significant side effect of chemotherapy and/or radiation therapy. The purpose of this study was to evaluate the effects of the homogenous amniotic membrane (HAM) as a biological dressing for oral mucositis induced by 5-fluorouracil (5-FU) in the labial fornix region of inferior incisors in rats.

METHODS

Sixty rats were divided into three groups: control (50% acetic acid), 5-FU (50% acetic acid and 5-fluorouracil-induced oral mucositis) and 5-FU+HAM (50% acetic acid and 5-fluorouracil-induced oral mucositis, and treated with HAM). Histological analyses were done 3, 7, 14 and 21 days after applying the acetic acid.

RESULTS

HAM showed not only no signs of rejection as well as an excellent tissue adherence to the ulcerated surface. Histomorphometric analysis indicated a lower quantity of inflammatory cells in the 5-FU+HAM group in all periods when compared to the other groups and there was a statistically significant difference in the 3- and 7-day periods (P<0.001).

CONCLUSIONS

The results of this study suggest that HAM was biocompatible with great adhesive power to the ulcerated surface, accelerated the healing process and exhibited anti-inflammatory activity. Further studies should be done to investigate the potential benefits of this material in clinical trials. HAM could lead to improved results as a biological dressing in treatment and management of oral mucositis in patients submitted to chemotherapy and/or radiation therapy.

Primary Acquired Melanosis of the Conjunctiva: Risks for Progression to Melanoma in 311 Eyes

PURPOSE

To evaluate the clinical features and risks for transformation of conjunctival primary acquired melanosis (PAM) into melanoma.

DESIGN

Noncomparative case series.

PARTICIPANTS

Three hundred eleven eyes with conjunctival PAM without melanoma at initial examination from a single-center tertiary referral center.

METHODS

Retrospective chart review with evaluation of the clinical features of PAM at initial presentation and follow-up. Times to PAM enlargement, recurrence, and transformation into melanoma were assessed using Kaplan-Meier estimates. Risk factors for these outcomes were analyzed using Cox proportional hazards regressions.

MAIN OUTCOME MEASURES

Primary acquired melanosis enlargement, recurrence, and transformation into melanoma.

RESULTS

Mean patient age at diagnosis of PAM was 56 years (range, 15-90), 62% were female, and 96% were Caucasian. The conjunctival quadrant(s) affected by PAM were temporal (57%), inferior (45%), nasal (42%), and superior (37%). The anatomic location(s) of PAM included bulbar conjunctiva (91%), limbal conjunctiva (55%), cornea (23%), forniceal conjunctiva (13%), palpebral conjunctiva (12%), and caruncle (11%). Primary acquired melanosis extended for a mean of 3 clock hours (range, 1-12). Initial management included observation (n = 194 eyes [62%]), biopsy combined with cryotherapy (n = 107 eyes [34%]), and topical chemotherapy and/or cryotherapy without biopsy (n = 10 [4%]). Of PAM that was observed, Kaplan-Meier estimates at 10 years revealed PAM enlargement in 35% and transformation into melanoma in 12%. Of those that underwent incisional or excisional biopsy, 10-year estimates of PAM recurrence and transformation into melanoma were 58% and 11%, respectively. Progression to melanoma occurred in 0% of cases of PAM without atypia, 0% of cases of PAM with mild atypia, and 13% of cases of PAM with severe atypia. Of the 9 patients with PAM who developed melanoma, none have developed systemic metastasis. Multivariable analysis revealed that the most significant factor for both PAM recurrence and progression to melanoma was extent of PAM in clock hours.

CONCLUSION

Primary acquired melanosis without atypia or with mild atypia shows 0% progression to melanoma, whereas PAM with severe atypia shows progression to melanoma in 13%. The greater the extent of PAM in clock hours, the greater the risk for transformation to melanoma.

[Conjunctival melanoma at corneoscleral limbus on primary acquired melanosis. A case report]

A 51-year-old Caucasian man consulted for a visual loss in the left eye due to corneal extension of a conjunctival melanoma. This conjunctival melanoma arose from primary acquired melanosis with atypia at the temporal corneoscleral limbus. The patient was treated using a combination of surgical excision with physical treatment by ocular proton therapy. Progression remained under control 11 months after treatment: no local tumour recurrence or metastasis was observed. Primary acquired melanosis with atypia must be regarded as a premalignant melanocytic lesion. Based on this case report, the authors focus on primary acquired melanosis and its risk of transformation to a conjunctival malignant melanoma.

Conjunctival tumors in children

PURPOSE OF REVIEW

Numerous conjunctival tumors can occur in children, originating from tissues of choristomatous, epithelial, melanocytic, vascular, fibrous, xanthomatous and lymphoid. Overall, 97% prove to be benign and only 3% are malignant.

RECENT FINDINGS

The most common malignancies include conjunctival lymphoma and melanoma. In our experience, the most common conjunctival tumors in children include nevus (64%), dermolipoma (5%), lymphangioma (3%) and capillary hemangioma (3%). Conjunctival nevi can manifest as a darkly pigmented (65%), lightly pigmented (19%) and completely nonpigmented (16%) mass. Most nevi occurred at the nasal or temporal limbus, without involvement of the cornea. Occasionally, they are located in the caruncle, but rarely are nevi found in the fornix or tarsal conjunctival surface. Intralesional cysts are visible in 65% of nevi. Change in nevus color over time has been noted in 5% of cases and change in nevus size has been documented in 7%. Evolution of conjunctival nevus into malignant melanoma is extremely low (<1%).

SUMMARY

Conjunctival nevus is the most common conjunctival tumor in children and fewer than 1% evolve into melanoma over time.

Differenzialdiagnose und Therapieoptionen bei Tumoren der Konjunktiva

The diagnostic classification of most conjunctival tumors is based on case history, inspection, and examination with the slit lamp microscope. Further imaging procedures are rarely indicated when malignant processes are not circumscribed. Clinical classification then also includes palpation and echographic examination of regional lymph nodes. Pigmented and nonpigmented melanocytic nevi are the most frequent conjunctival tumors. An important practical biomicroscopic cardinal symptom of the most frequent nevi is the presence of epithelial pseudocysts. Essential in practice is the histopathological confirmation of the clinical diagnosis, e.g., distinguishing between nonpigmented melanomas and sebaceous gland carcinomas with a pagetoid growth pattern or squamous cell carcinomas. Depending on the course and findings, the following therapeutic measures can be indicated: cryotherapy, chemotherapy, radiotherapy, modified enucleation, orbital exenteration, or a combination of different methods.

Primary acquired melanosis of the conjunctiva: experience with 311 eyes

PURPOSE

To evaluate clinical features and risks for transformation of conjunctival primary acquired melanosis (PAM) into melanoma.

METHODS

Retrospective chart review and Kaplan-Meier estimates of times to PAM enlargement, recurrence, and transformation into melanoma.

MAIN OUTCOME MEASURES

PAM enlargement, recurrence, and transformation into melanoma.

RESULTS

The mean patient age at diagnosis of PAM was 56 years; 62% were female and 96% Caucasian. The conjunctival quadrant(s) affected by PAM and its extent in clock hours were recorded. Initial management included observation in 62%, biopsy combined with cryotherapy in 34%, and other methods in 4%. Of PAM that was observed, Kaplan-Meier estimates at 10 years revealed PAM enlargement in 35% and transformation into melanoma in 12%. Of those that underwent incisional or excisional biopsy, 10-year estimates of PAM recurrence and transformation into melanoma were 58% and 11%, respectively. Progression to melanoma occurred in 0% of PAM without atypia, 0% of PAM with mild atypia, and 13% of PAM with severe atypia. Multivariable analysis revealed that the most significant factor for both PAM recurrence and progression to melanoma was extent of PAM in clock hours.

CONCLUSION

PAM without atypia or with mild atypia shows 0% progression into melanoma, whereas PAM with severe atypia shows progression into melanoma in 13%. The greater the extent of PAM in clock hours, the greater the risk for transformation into melanoma.

Primary acquired melanosis of the conjunctiva

BACKGROUND

Primary acquired melanosis (PAM) presents as a unilateral patchy area of conjunctival pigmentation mostly found in middle-aged or elderly white patients. Because PAM has the potential of becoming malignant, it is important to recognize PAM and to rule out other causes of pigmented lesions. The presence or absence of atypia is helpful in determining the potential for malignancy, because PAM without atypia is usually benign, whereas PAM with atypia may convert into a conjunctival melanoma. If atypia is present, the presence or absence of epithelioid cells and the pattern of intraepithelial growth are the main factors in determining the likelihood of neoplastic transformation. However, atypia can only be determined with histopathologic examination. Therefore, a biopsy is usually recommended.

CASE REPORT

A 72-year-old white man presented for his annual examination with no visual complaints. His ocular history was remarkable for early cataracts and for a choroidal nevus. Slit lamp examination found a large dark area of elevated conjunctival pigmentation at the medial canthus that extended onto the superior bulbar conjunctiva and superior palpebral conjunctiva in the left eye. No conjunctival pigmentation had been noted previously. Results of a biopsy indicated primary acquired melanosis with atypia. The lesion was surgically excised, and the conjunctiva was reconstructed with an amniotic membrane graft. The patient was subsequently treated with topical 5-fluorouracil chemotherapy. There have been no signs of recurrence to date after his treatment.

CONCLUSION

Because of the potential for malignancy, biopsies of all cases of primary acquired melanosis are indicated. If atypia is present, treatment options include local excision, cryotherapy, and topical chemotherapy.

Malignant fibrous histiocytoma of the conjunctiva

Fibrous histiocytomas are mesenchymal tumours composed of cells with fibroblastic to histiocytic differentiation. They can occur in any part of the body including the orbital tissues. To date, there are 18 cases of fibrous histiocytoma arising from the corneoscleral limbus reported in the literature. Eleven of these were classified as benign, and the rest were malignant fibrous histiocytomas. Benign fibrous histiocytomas have been reported in the orbit, eyelid, episclera and conjunctiva. Malignant fibrous histiocytoma has been well described in the orbit, but rarely as a primary conjunctival tumour. The rarity of the tumour makes its diagnosis and management a challenge. Herein, the clinicopathological features of a case of malignant fibrous histiocytoma are presented and its management with wide excision and cryotherapy followed by ocular reconstruction with amniotic membrane transplant is discussed.

Treatment of large conjunctival nevus by resection and reconstruction using amniotic membrane

BACKGROUND

Nevus of the bulbar conjunctiva is a benign pigmented lesion of the ocular surface. Unless a biopsy is required for ruling out malignant melanoma, a nevus is usually excised for cosmetic reasons only. However, with large lesions involving two or more quadrants of the bulbar conjunctiva, a total resection can be difficult. In this report, we present a case of a huge nevus treated by surgical excision and amniotic membrane transplantation for reconstruction of the bulbar conjunctiva.

METHODS

A 54-year-old Japanese man was referred to our clinic with suspected malignant tumor of the bulbar conjunctiva in his right eye. A large and diffuse pigmented tumor with numerous small cysts was present mainly on the upper bulbar conjunctiva. Resection of the conjunctival tumor and amniotic membrane transplantation for reconstruction of the bulbar conjunctiva were performed.

RESULTS

The histopathological diagnosis was conjunctival nevus. Epithelialization of the bulbar conjunctiva over the amniotic membrane sheet was completed 4 weeks after resection. At 44-month follow-up, there was no recurrence or any postoperative complication.

CONCLUSION

Surgical resection combined with reconstruction by amniotic membrane transplantation is effective for the treatment of large conjunctival nevus.

[Amniotic membrane transplantation for oculopalpebral and reconstructive surgery]

INTRODUCTION

Amniotic membrane has been used for many years for ocular surface defects. It is also commonly used in laboratories for cellular growth. Amniotic membrane has antiadhesive properties, can promote epithelialization, and decrease neovascularization, inflammation, and fibrosis. There is no histocompatibility problem, as amniotic membrane has no HLA antigens. In this study, amniotic membrane transplantation was used for oculopalpebral and reconstructive surgery as an alternative to the oral mucous graft, particularly in the reconstruction of the conjunctival fornices after inflammatory disease, burns, conjunctival tumors, and enucleation with orbital implants.

MATERIAL AND METHOD

Forty-eight interventions using amniotic membrane transplantation were done on 44 patients. In 16 cases conjunctival fornices were created or reconstructed, allowing the installation of an ocular prosthesis; 14 had reconstruction of fornices for inflammatory disease, or chemical or thermal burns; 11 had palpebral skin and conjunctival reconstruction (malformations or skin tumours); and seven cases had conjunctival reconstruction after conjunctival tumor excision.

RESULTS

Thirty-nine cases presented good functional and cosmetic results. One case had no follow-up. Eight cases gave poor results: four cases of conjunctival fornix refection (with two irradiated cavities), three cases of fornix reconstruction after chemical burn, and one case in whom palpebral reconstruction partially failed (coloboma).

DISCUSSION AND CONCLUSION

Functional and cosmetic results were good for 39 cases, allowing ocular prosthetic equipment when necessary. In nine cases, two complete fornix retractions and two partial fornix retractions were observed; one palpebral reconstruction for malformation partially failed; and four cases (two with amniotic membrane and two with oral mucus graft) required a second surgery to obtain a satisfactory result. Amniotic membrane transplantation is an excellent alternative material to oral mucous membrane in oculopalpebral and reconstructive surgery except when graft rigidity is necessary. Its use is more difficult in cases of chemical burns or after orbital irradiation.

Proton radiotherapy as an alternative to exenteration in the management of extended conjunctival melanoma

BACKGROUND

Diffuse and multifocal patterns of conjunctival melanoma may not be treatable with standard eye-sparing methods. The purpose of this study was to evaluate the usefulness of proton beam radiation therapy as an alternative to exenteration.

METHODS

Twenty patients with extended conjunctival melanoma were treated by proton beam irradiation. Most cases were T3 tumours which were not accessible to brachytherapy due to their extension, localisation with fornical or caruncular involvement. Only 2 patients had a tumour limited to the bulbar conjunctiva. Both were recurrent tumours with multiple lesions. Sixteen cases were recurrences after various pre-treatments. The area of the conjunctiva which was suspected to have microscopic disease was treated by 31 Gy in 6 fractions. The "high risk" areas with a clinically detectable tumour (primary target volume) were treated by an additional boost using a smaller beam size and applying 2 fractions up to 45 Gy. An individually shaped compensator was brought into the beam to modify the range of the protons so that the eye was irradiated only at a depth of 2 mm.

RESULTS

The mean follow-up time was 38.1+/-26.6 months (median 34 months). Recurrent disease occurred in 6 cases (30%); 2 of them outside the irradiated volume, 3 within the target volume treated by 31 Gy, and just one in the primary target volume treated by 45 Gy. An exenteration followed only in two patients (10%). 6 patients (30%) suffered from metastatic disease and 4 (20%) of them have died by now. During follow up we found no statistically significant association between the occurrence of local recurrence after proton radiotherapy and the development of metastases. Best corrected visual acuity remained stable in 12 cases (60%); in 14 patients the best corrected visual acuity was 0.25 or better. A sicca-syndrome developed in 19/20 patients. However, only 10/20 patients used artificial tears more than 5x/d. A focal cataract developed in 7 patients (35%). There was eyelash loss in the area of irradiated eyelids. In 4 cases a limbal stem cell deficiency occurred with the consequence of corneal vascularisation.

CONCLUSIONS

Proton radiotherapy may serve as an alternative to exenteration in case of T3 and diffuse T1 or T2 conjunctival melanomas.

Amniotic Membrane Transplantation for Ocular Surface Reconstruction

The amniotic membrane, composed of 3 layers, the epithelium, basement membrane, and the stroma, was first used along with the chorion as a biologic membrane to promote healing of skin burns in 1910. In ophthalmology, it was used in 1940 in the management of conjunctival defects. Its revival in the 1990s was due to its ability to reduce ocular surface inflammation and scarring, promote rapid epithelialization due to the presence of growth factors, and antimicrobial properties. This has resulted in its application in several ocular disorders. A review of the literature shows that amniotic membrane is definitely beneficial in some but not all pathology. The future of amniotic membrane transplantation is very exciting, especially in the field of limbal stem cell research. However, further work is needed to elucidate whether it functions merely as a biologic contact lens or whether it has additional benefits.

Amniotic membrane transplantation for the reconstruction of the ocular surface in three cases

This paper describes the use of amniotic membrane in the reconstructive surgical repair of generalized keratomalacia, ankyloblepharon, and after fibrous histiocytoma removal in two dogs and a cat. Case 1 was an 11-year-old female Yorkshire terrier with severe bullous keratomalacia in the left eye (OS). A frozen canine amniotic membrane graft and a third eyelid flap were applied. At day 80 postoperatively, only a mild scar and corneal vascularization were present. Case 2 was a 4-year-old female Siamese cat with symblepharon of both eyes after rhinotracheitis. Resection of the conjunctiva and frozen canine amniotic membrane transplant were performed. One month later, there was a little corneal scarring and corneal vascularization. Case 3 was a 6-year-old female terrier with a scleral and corneal mass at the 11-12 o'clock position (OS). Resection of the mass and amniotic membrane transplantation were performed. The mass was a fibrous histiocytoma localized to the sclera and cornea. This eye healed with mild conjunctivalization and no pigmentation. Amniotic membrane transplantation can be used as a method of reconstruction of the ocular surface with good repair of the cornea and minimal scarring in small animals.

Clinical follow-up of conjunctival malignant melanoma

PURPOSE

To investigate the clinical features and course of conjunctival malignant melanoma in Korea.

METHODS

The medical records of 15 patients, 5 males and 10 females, diagnosed with conjunctival malignant melanoma who had been treated at Severance Hospital from May 1991 to March 2004 were reviewed retrospectively. The clinical parameters of the patients, tumors, and treatment were analyzed for their relation to outcome measures.

RESULTS

The mean age at the time of diagnosis was 53.4 years (+/- 11.7 years). In all cases, the disease was unilateral and all patients had experienced at least one recurrence. Local lymph node metastasis was found in 3 patients (20%) and the mean time to metastasis was 3.5 years. Systemic metastasis was found in 6 patients (40%) and the mean time to metastasis was 9.3 years. There were 5 cases of tumor-related death (33.3%), 4 of which were attributed to systemic metastasis. The Kaplan-Meier estimates of cumulative survival rate were 90% at 30 months and 56.6% at 70 months.

CONCLUSIONS

Although conjunctival malignant melanoma is a rare disease, it is life-threatening and complete tumor excision at an early stage is mandatory, as is additional therapy to prevent local recurrence and systemic metastasis.

Hughes technique, amniotic membrane allograft, and topical chemotherapy in conjunctival melanoma with eyelid involvement

A 59-year-old woman presented with a pigmented mass in the inferior tarsal conjunctiva of the left eye with an associated diffuse, multifocal pigmentation involving largely the inferior half of the bulbar conjunctiva, fornix, and eyelid skin. Histopathologic examination of map biopsies disclosed conjunctival melanoma from primary acquired melanosis. Surgical excision of the inferior bulbar conjunctiva, fornix, and lower eyelid with histopathologic free margins was performed. Adjuvant cryotherapy was applied. The bulbar conjunctiva and lower fornix were reconstructed with an amniotic membrane allograft. Lower eyelid reconstruction was accomplished by use of the Hughes technique. Topical mitomycin C (0.04%) was applied after surgery. After 2 years of follow-up, no tumor recurrence has been detected and the eyelid and conjunctival defect have been satisfactorily corrected. This combined surgical procedure using amniotic membrane allograft and a composite tarsoconjunctival flap is shown to be useful in the treatment of an advanced conjunctival neoplasia with extensive eyelid involvement.