Cryopreserved Ultra-Thick Human Amniotic Membrane for Conjunctival Surface Reconstruction After Excision of Conjunctival Tumors

Presence of heavy chain-hyaluronan/pentraxin 3 (HC-HA/PTX3) complex in human umbilical cord

The heavy chain (HC)-hyaluronan (HA)/pentraxin 3 (HC-HA/PTX3) complex is formed by tumor necrosis factor-stimulated gene-6 (TSG-6) catalyzing the covalent (ester bond) transfer of HC1 from inter-α-trypsin inhibitor (IαI) to HA followed by tight binding of PTX3. The presence of such a complex has been found in human amniotic membrane (AM) and is considered to be a major matrix component responsible for its anti‑inflammatory and anti‑scarring properties to promote regenerative healing. Because the therapeutic potentials of AM and umbilical cord (UC) are similar, we herein evaluated whether human UC also contains HC-HA/PTX3. Immunostaining of UC cross-sections showed abundant PTX3, HC1, HA, TSG-6, and bikunin. Western blot analysis suggested the presence of HC1 complex bound via a NaOH-sensitive bond and tightly bound to PTX3 multimer in UC and AM extracts but not in chorion and placenta extracts. HC-HA/PTX3 was purified from UC extract by successive runs of density gradient ultracentrifugation and verified the presence of HC1 but not HC2 or HC3 based on western blot analysis. These results suggest the presence of HC-HA/PTX3 complex in UC is similar to AM.

The current alternative for ocular surface and anophthalmic socket reconstruction, cryopreserved umbilical amniotic membrane (cUAM)

PURPOSE

This report presents the results of using cryopreserved umbilical amniotic membrane (cUAM) as an alternative mucosal graft for ocular surface reconstruction in cases of anophthalmic socket contracture (ASC), cicatricial entropion (CE), and conjunctival-scleral defects.

METHODS

The study included patients who underwent non-commercial implantation of cUAM grafts (prepared by corneal banking methods) for ASC, CE, conjunctival defect, and scleral melting. The main success criteria for this study were the comfortable fitting of the ocular prosthesis in ASC patients, the natural eyelid position in CE patients, and the degree of conjunctivalisation in melting patients.

RESULTS

cUAM transplantation was performed in 2 patients who could not use a prosthetic eye due to conjunctival contracture, 2 patients with CE, and 1 patient with conjunctival defect and 1 patient with conjunctival-scleral melting. The primary outcome was achieved in 83.3% (5/6) of patients. In one patient with CE, partial healing was achieved due to the persistence of CE in the medial upper eyelid.

CONCLUSIONS

cUAM is a viable alternative to mucosal grafting for reconstructing the bulbar and palpebral conjunctival surface, fornix, and orbit, with reduced donor morbidity and shorter surgical time. Its regenerative ability allows for tissue defect healing and improves cosmetic appearance through epithelialization within weeks.

Clinical use of cryopreserved ultra-thick human amniotic membrane for anophthalmic socket contracture

PURPOSE

To study the use of ultra-thick human amniotic membrane for management anophthalmic socket contracture.

METHODS

A prospective study done at King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia. Thirty-six patients (45 eyelids) were involved. Contracted socket caused by trauma, previous surgery or radiotherapy, delay in use of prosthesis, Congenital Anophthalmia/Microphthalmia, and Anophthalmia secondary to Enucleation/Evisceration were included in the study.

RESULTS

Thirty-three patients (42 eyelids) underwent fornix reconstruction with cryopreserved ultra-thick human amniotic membrane. Mean ± SD age at surgery was (40.90 ± 17.32) years. Mean follow up was 10.5 months. Grade II fornix contracture was the most common type in 23 (54.8%) eyelids. The most common involved primary diagnosis was Anophthalmia secondary to Enucleation/Evisceration (n = 13). The incidence of pyogenic granuloma (PG) after surgery was seen in 8 eyelids (19.0%).

CONCLUSION

Anophthalmic contracted socket secondary to significant history of multiple PG excision (> 5 times) and secondary to enucleation/evisceration were associated with good surgical outcome. Cryopreserved ultra-thick human amniotic membrane is an ideal material for the management of anophthalmic socket contracture.

Pilot study of a glue-less, suture-less amniotic membrane for pterygium excision

PURPOSE

Pterygium is a non-cancerous, fibrovascular growth of the bulbar conjunctiva that can cause visual disturbance, ocular pain, and cosmetic concerns. Surgical management is required in certain cases, which consists of excising the pterygium and associated Tenon's, then overlaying the bare sclera with an autograft or amniotic membrane using glue or sutures. The purpose of this study is to assess outcomes of pterygium repair using a newly developed self-adhesive amniotic membrane that does not require glue or sutures for fixation.

METHODS

Chart review of pterygium excision using a new self-adhesive amniotic membrane from a single surgical practice from 2012-2018. Descriptive statistics from 51 primary cases of pterygium excision were included.

RESULTS

Pterygium recurrence occurred in 3 of the 51 self-adhesive amniotic membrane cases studied, resulting in a recurrence rate of 5.9%. Pterygium excision with the self-adhesive amniotic membrane had high rate of pyogenic granuloma formation of 27%. Self-adhesive amniotic membranes were found to perform comparably to more widely used techniques for pterygium excision, namely amniotic membranes and conjunctival autographs with glue or sutures. However, the self-adhesive grafts are associated with substantially more pyogenic granuloma formation.

CONCLUSION

Self-adhesive amniotic membranes offer comparable efficacy for preventing pterygium recurrence in comparison to other amniotic membranes and the conjunctival autograft. The incidence of pyogenic granuloma formation is higher in self-adhesive grafts compared to other widely used options.

Results of Resorbable and Running Sutured Amniotic Multilayers in Sterile Deep Corneal Ulcers and Perforations

PURPOSE

To present the results of a modified surgical technique for secure tightening and fixation of multilayer amniotic membranes (AMs) in sterile deep or perforating corneal ulcers.

METHODS

We retrospectively analyzed the data of patients suffering from corneal ulcers who had been treated between February 2016 and June 2018 with running and resorbable sutures to fixate multilayer AMs. The parameters analyzed were gender, age, etiology of corneal ulcer, ulcer diameter, corneal thickness (CST) before and after the microsurgical procedure as measured with optical coherence tomography, number of inlays, repeat surgical procedures, follow-up duration in months, and rate of success (defined as a stable anterior chamber with improved CST, a negative Seidel test, and no need for any microsurgical keratoplasty during the first 6 months after treatment). The results were statistically evaluated using the Wilcoxon test. A P-value ≤0.05 was considered to show a statistically significant difference.

RESULTS

The CST increased significantly after AM transplantation (from 206.26 ± 114.93 μm at baseline to 454.70 ± 244.08 μm at 1-3 months; P < 0.001). Repeat multilayer transplantation was required in 7 of the 23 patients included (30.4%), in 6 of whom the treated eye was stable at month 6. In 2 of the 23 patients, perforating keratoplasty became necessary. One patient also demanded such a procedure to improve his visual acuity. The success rate was 91.3% (n = 21).

CONCLUSIONS

Running resorbable suture fixation of multilayer AMs proved to be an efficient means for the treatment of noninfectious deep or small perforating corneal ulcers.

Novel Use of Cryopreserved Ultra-thick Human Amniotic Membrane for Management of Anophthalmic Socket Contracture

PURPOSE

To describe the use of cryopreserved ultra-thick human amniotic membrane for management of anophthalmic socket contracture.

METHODS

A chart review was performed to identify patients undergoing fornix reconstruction with cryopreserved ultra-thick human amniotic membrane for management of anophthalmic socket contracture. Patient demographics, disease etiology, and data regarding postoperative prosthesis fit and complications were collected.

RESULTS

The technique is described in 3 female patients with anophthalmic socket contracture who underwent fornix reconstruction using cryopreserved ultra-thick human amniotic membrane. All patients had excellent prosthesis fit at final follow up (range, 10-14 months). There were no clinically significant complications and no reoperations were performed. One pyogenic granuloma developed and was excised without affecting ocular prosthesis fit.

CONCLUSIONS

Cryopreserved ultra-thick human amniotic membrane is easy to use, well tolerated, and produces good outcomes for management of anophthalmic socket contracture.

The Use of Umbilical Amnion for Conjunctival Socket, Fornix, and Eyelid Margin Reconstruction

PURPOSE

To describe outcomes using umbilical amnion for conjunctival fornix, socket, and eyelid margin reconstruction.

METHODS

A medical record review was performed to identify patients who had received umbilical amnion over a 2-year period in their department. Patient demographics, disease etiology, and data regarding surgical outcomes were collected. The primary outcome was the success rate of the surgical intervention.

RESULTS

Twenty-one patients received umbilical amnion for anophthalmic socket contracture (n = 16), orbital implant exposure (n = 3), ocular surface burn (n = 1), and cicatricial entropion repair (n = 1). The primary outcome was met in 76% of patients overall. In anophthalmic socket contracture, the primary outcome was met in 86% and 0% of patients with acquired and congenital anophthalmia, respectively. The primary outcome was met in all cases of orbital implant exposure and cicatricial entropion. The primary outcome was not met in a Roper-Hall grade IV ocular surface burn.

CONCLUSIONS

Umbilical amnion is an ideal substrate graft for reconstruction of the conjunctival fornix, socket, and eyelid margin. Umbilical amnion appears to be efficacious for the management of socket contracture in acquired anophthalmia, orbital implant exposure, and cicatricial entropion. Further experience is needed to determine the efficacy of umbilical amnion in ocular surface burns.

MSCs inhibits the angiogenesis of HUVECs through the miR-211/Prox1 pathway

The aim of this study was to investigate the effect of mesenchymal stem cells (MSCs) on the angiogenesis of human umbilical vein endothelial cells (HUVECs). MSCs were subconjunctival injected into rat corneal alkali burn models. Their impacts on the degree of corneal neovascularization (CNV) and corneal opacity were evaluated at 3, 6, 9 and 12 days after injection. An in vitro experiment of MSCs affecting HUVECs angiogenesis was performed and evaluated using the tube formation assay. The results showed that both CNV and corneal opacity were decreased in rats after MSCs injection. In HUVECs, angiogenesis of cells was inhibited by miR-211 overexpression. miR-211 negatively regulated Prox1 expression. Knockdown of miR-211 blocked the decrease of Prox1 expression induced by MSCs and the inhibitory effect of MSCs on the angiogenesis of HUVECs. The critical role of miR-211 in MSCs inhibition of corneal angiogenesis was confirmed in rat experiments. We concluded that MSCs inhibited the angiogenesis of HUVEC through miR-211 mediating the down-regulation of Prox1.

Transplantation of human amnion prevents recurring adhesions and ameliorates fibrosis in a rat model of sciatic nerve scarring

Peripheral nerve fibrosis and painful adhesions are common, recurring pathological sequelae following injury. In this study, vital human amnion (hAM), an increasingly interesting biomaterial for regenerative medicine, was investigated as a novel therapy. hAM was first analyzed in vitro regarding its anti-adhesive characteristics. Then, the reflected region of hAM which was identified as more suitable, was transplanted into female Sprague Dawley rats with recurring sciatic nerve scarring (n = 24) and compared with untreated controls (n = 30) at one, four and twelve weeks. Immune response and fibrosis were investigated by (immuno)histochemical analysis. Nerve structure was examined and function determined using electrophysiology and gait analysis. Here we identified strongly reduced adhesions in the hAM-treated rats, displaying a significant difference at four weeks post transplantation compared to untreated controls (p = .0052). This correlated with the in vitro cell attachment test on hAM explants, which demonstrated a distinctly limited ability of fibroblasts to adhere to amniotic epithelial cells. Upon hAM transplantation, significantly less intraneural fibrosis was identified at the later time points. Moreover, hAM-treated rats exhibited a significantly higher sciatic functional index (SFI) after four weeks compared to controls (p < .05), which indicated a potentially pro-regenerative effect of hAM. As a possible explanation, an impact of hAM on the endogenous immune response, including T cell and macrophage subsets, was indicated. We conclude that hAM is strongly effective against recurring nerve scarring and induces an anti-fibrotic and pro-regenerative effect, making it highly promising for treating adhesion-related disorders.

STATEMENT OF SIGNIFICANCE

Abnormal fibrotic bonding of tissues, frequently involving peripheral nerves, affects millions of people worldwide. These so-called adhesions usually cause severe pain and drastically reduce quality of life. To date, no adequate treatment exists and none is routinely used in the clinical practice. In this study, vital human amnion, the innermost of the fetal membranes, was transplanted in a rat model of peripheral nerve scarring and recurring adhesions as novel therapeutic approach. Amniotic cells have already demonstrated to feature stem-cell like properties and produce pro-regenerative factors, which makes the amnion an increasingly promising biomaterial for regenerative medicine. We identified that its transplantation was very effective against peripheral nerve scarring and distinctly reduced recurring adhesions. Moreover, we identified a pro-regenerative effect. This study showed that the amnion is a highly promising novel therapeutic approach for adhesion-related disorders.

Umbilical Cord Patch Transplantation for Corneal Perforations and Descemetoceles

PURPOSE

To evaluate the clinical outcome of umbilical cord patch (UCP) transplantation for deep corneal ulcers with perforations and descemetoceles.

METHODS

In this retrospective, noncomparative, interventional case series, 11 eyes of 11 patients with corneal perforation or descemetocele were included. The thickness and microstructure of UCP were measured. All eyes were treated with UCP and amniotic membrane transplantation for corneal reconstruction. Corneal ulcer healing, corneal thickness, anterior chamber formation, and best-corrected visual acuity (BCVA) were recorded and analyzed.

RESULTS

The thickness of human UCP is 398.6 ± 102.8 μm (n = 5) with compact aligned fibers. The average age was 56.2 ± 15.8 (ranging from 22 to 75) years. The mean follow-up period was 7.1 ± 1.7 (ranging from 5 to 10) months. Four patients had descemetocele and 7 had perforation. The anterior chambers in all the 7 perforated corneas were formed at postoperative day 1. All patients regained a normal corneal thickness and smooth corneal surface within the first postoperative month. The vision improved in 10 eyes and remained unchanged in 1 eye. No recurrence nor side effects occurred during the follow-up.

CONCLUSIONS

UCP can serve as an alternative material in the treatment of corneal perforations and descemetoceles. This treatment option is also beneficial in those countries with limited cornea donors and eye bank services.

Advances in the management of conjunctival melanoma

Malignant melanoma of the conjunctiva is a rare but serious condition. Over the last several years, there have been important advances in the classification, diagnosis, and treatment of this condition. Recent cytogenetic and immunohistochemical studies are increasing understanding of its tumorigenesis. Diagnosis, although still made via histopathology, has been aided with imaging techniques such as ultrasound biomicroscopy and anterior segment optical coherence tomography. Primary treatment consists of surgical excision. But adjuvant treatments with cryotherapy, topical chemotherapy, and radiation therapy have shown increased success. Sentinel lymph node biopsy has shown early promise of detecting micro-metastasis. Long term follow-up of patients with conjunctival melanoma with systemic surveillance is necessary to detect recurrences and metastases.