Update on the application of amniotic membrane in immune-related ocular surface diseases

The revolutionary role of placental derivatives in biomedical research

The human placenta is a transient yet crucial organ that plays a key role in sustaining the relationship between the maternal and fetal organisms. Despite its historical classification as "biowaste," placental tissues have garnered increasing attention since the early 1900s for their significant medical potential, particularly in wound repair and surgical application. As ethical considerations regarding human placental derivatives have largely been assuaged in many countries, they have gained significant attention due to their versatile applications in various biomedical fields, such as biomedical engineering, regenerative medicine, and pharmacology. Moreover, there is a substantial trend toward various animal product substitutions in laboratory research with human placental derivatives, reflecting a broader commitment to advancing ethical and sustainable research methodologies. This review provides a comprehensive examination of the current applications of human placental derivatives, explores the mechanisms behind their therapeutic effects, and outlines the future potential and directions of this rapidly advancing field.

Severe corneal manifestations of graft-versus-host disease: Experience of a tertiary referral center

PURPOSE

Graft-versus-host disease (GVHD) is a common complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). GVHD may affect several organs, including ocular manifestations, ranging from dry eye syndrome to sight-threatening corneal ulceration or perforation. Limited information is available about characteristics and treatments of ocular GVHD and its relation to general prognosis.

METHODS

We retrospectively analyzed data from 140 patients from a tertiary ophthalmological center and confronted it with systemic data from a national bone marrow transplantation database.

RESULTS

Most patients were treated with artificial tears, vitamin A ointment, topical anti-inflammatory agents (mostly cyclosporin and steroid drops), autologous serum eye drops, scleral lenses and punctal silicone plugs. We identified a high proportion of severe ocular manifestations, such as corneal ulceration or perforation (33 patients, 23.6 %), occurring with a median of 39 months (interquartile range (IQR): 16-96) after transplantation. Overall survival did not differ in patients with severe to non-severe ocular GVHD (5-year mortality of 8 % without and 13 % with severe ocular involvement, p = 0.53 for survival curves comparisons). Multivariate analysis revealed that male patients and HLA mismatch allo-HSCT were independently associated with an increased risk of severe ocular manifestations. Moreover, a high proportion of complications occurred after non-steroidal anti-inflammatory drug (NSAID) treatments.

CONCLUSIONS

Patients with GVHD should therefore undergo close ophthalmological monitoring and they should not, in any case, be treated with local ocular NSAIDs, due to the severity of potential complications.

Healing the cornea: Exploring the therapeutic solutions offered by MSCs and MSC-derived EVs

Affecting a large proportion of the population worldwide, corneal disorders constitute a concerning health hazard associated to compromised eyesight or blindness for most severe cases. In the last decades, mesenchymal stem/stromal cells (MSCs) demonstrated promising abilities in improving symptoms associated to corneal diseases or alleviating these affections, especially through their anti-inflammatory, immunomodulatory and pro-regenerative properties. More recently, MSC therapeutic potential was shown to be mediated by the molecules they release, and particularly by their extracellular vesicles (EVs; MSC-EVs). Consequently, using MSC-EVs emerged as a pioneering strategy to mitigate the risks related to cell therapy while providing MSC therapeutic benefits. Despite the promises given by MSC- and MSC-EV-based approaches, many improvements are considered to optimize the therapeutic significance of these therapies. This review aspires to provide a comprehensive and detailed overview of current knowledge on corneal therapies involving MSCs and MSC-EVs, the strategies currently under evaluation, and the gaps remaining to be addressed for clinical implementation. From encapsulating MSCs or their EVs into biomaterials to enhance the ocular retention time to loading MSC-EVs with therapeutic drugs, a wide range of ground-breaking strategies are currently contemplated to lead to the safest and most effective treatments. Promising research initiatives also include diverse gene therapies and the targeting of specific cell types through the modification of the EV surface, paving the way for future therapeutic innovations. As one of the most important challenges, MSC-EV large-scale production strategies are extensively investigated and offer a wide array of possibilities to meet the needs of clinical applications.

Diagnosing and Managing Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis in Adults: Review of Evidence 2017-2023

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening reactions associated with long-term disabling sequelae. In the acute phase, the best supportive care in expert centers is the cornerstone of treatment. The follow-up is prolonged and multidisciplinary, according to the patient's needs. In this paper, we review the evidence from 2017 to 2023 for the diagnosis and management of SJS/TEN in adults. On the basis of this review and our own experience, we present recommendations for the diagnosis of SJS/TEN in adults, management in the acute phase (best supportive care; prevention of infections; skin, ocular, and other mucosa management; intensive care measures; and etiological treatment), and follow-up. The most frequent sequelae are cutaneous, ocular, and psychological. High-quality studies assessing the efficacy of immunomodulating agents (eg, cyclosporine, corticosteroids, intravenous Igs, and anti-TNF agents) in accelerating healing and reducing mortality are still lacking. In addition, we propose avenues for future studies.

Pseudopterygia in Fuchs Superficial Marginal Keratitis: Clinical Course and Surgical Outcomes

PURPOSE

Surgery for pseudopterygia in Fuchs superficial marginal keratitis (FSMK) bears the risk of corneal perforation, as described in a few case reports. The aim of this case series was to understand the clinical course and surgical outcomes of pseudopterygia in FSMK.

METHODS

A retrospective case series included patients meeting FSMK criteria with pseudopterygia in at least 1 eye. The severity grading of pseudopterygia and peripheral infiltration events at follow-up were analyzed. Pseudopterygia involving corneal central 3 mm diameter (grade III) received surgery. Peripheral corneal infiltrate events within 1 week after surgery were recorded.

RESULTS

Thirty-three eyes of 19 patients (8 men, 11 women; age 40-85 years; mean, 65 years) were included, with an average 48.1-month follow-up (range 0-188.8 months). At presentation, 7 eyes (21%) had grade III pseudopterygia. One patient showed corneal perforation 3 days after "pterygium" surgery elsewhere. The contralateral eye met the diagnosis of FSMK. During follow-up, 16 eyes (49%) exhibited peripheral corneal infiltrates, and 7 eyes (21%) showed progression of pseudopterygia to higher grades before or without any surgery. Ten eyes with grade III pseudopterygia underwent surgery. The best-corrected visual acuity in Logarithm of the Minimum Angle of Resolution improved from 0.34 ± 0.18 (range 0.05-0.52) to 0.13 ± 0.11 (range 0.05-0.4) ( P = 0.0023). Six eyes (60%) developed peripheral corneal infiltrates within 1 week after surgery, which responded well to topical corticosteroids.

CONCLUSIONS

Pseudopterygia in FSMK may progress to threaten visual acuity. Surgical excision can be safe and can effectively improve vision on the condition that the patients are closely followed in the early postoperative period to notice the corneal infiltrates.

Conjunctival squamous metaplasia on amniotic membrane in Stevens-Johnson syndrome: a case report

BACKGROUND

To present a case of conjunctival growth on the amniotic membrane and subsequent pathology revealing conjunctival squamous metaplasia in a patient with Stevens-Johnson syndrome.

CASE PRESENTATION

A 21-year-old female presented with painful, blurred vision in both eyes for two weeks. She was diagnosed with Stevens-Johnson syndrome 5 weeks before. Due to bilateral corneal epithelial defects, ProKera®, an amniotic membrane corneal bandage with a polycarbonate ring, was placed in both eyes. However, three weeks later, a slit-lamp examination revealed vascularized tissue growth from the palpebral conjunctiva to the amniotic membrane, along with symblepharon formation in the left eye. The patient underwent conjunctival biopsy, amniotic membrane removal, and symblepharon release. Pathology report showed the growth of squamous epithelium on the acellular amniotic membrane. Immunohistochemistry further supported the diagnosis, revealing squamous markers through p40 staining and highlighting the presence of the amniotic membrane using trichrome stain. Three months later, the patient's visual acuity had improved to 20/25 and no symblepharon was noted.

CONCLUSIONS

This is the first case of conjunctival squamous metaplasia on amniotic membrane associated with Stevens-Johnson syndrome. Our case indicates that, despite the anti-inflammatory properties of amniotic membrane, conjunctival squamous metaplasia may arise after amniotic membrane grafting due to intense inflammation in Stevens-Johnson syndrome. Clinicians should conduct regular monitoring before amniotic membrane dissolution to preclude the development of conjunctival squamous metaplasia on the membrane and potential invasion into the cornea.

Efficacy of Fresh Versus Preserved Amniotic Membrane Grafts for Ocular Surface Reconstruction: Meta-analysis

Amniotic membrane transplantation is commonly employed in ophthalmology to mend corneal epithelial and stromal defects. Its effectiveness in restoring the ocular surface has been widely acknowledged in clinical practice. Nevertheless, there is ongoing debate regarding the comparative effectiveness of using fresh amniotic membranes versus preserved ones. The objective of this meta-analysis was to ascertain whether there is a disparity in the effectiveness of fresh versus preserved amniotic membrane in the restoration of the ocular surface in clinical practice. The study utilized the following keywords: "fresh amniotic membrane," "preserved amniotic membrane," "amniotic membrane transplantation," and "ocular surface reconstruction." The study conducted a comprehensive search for relevant studies published until April 18, 2024. Seven different databases, namely PubMed, Web of Science, Embase, Cochrane, China Knowledge, China Science and Technology Journal VIP database, and Wanfang database, were utilized. The search was performed using the keywords "fresh amniotic membrane," "preserved amniotic membrane," "amniotic membrane transplantation," and "ocular surface reconstruction." The process of literature review and data extraction was carried out separately by two researchers, and all statistical analyses were conducted using Review Manager 5.4.1. The final analysis comprised nine cohort studies, encompassing a total of 408 participants. The statistics included six outcome indicators: visual acuity (relative risk [RR] = 1.07, 95% confidence interval [CI] = 0.93-1.24, I2 = 0); amniotic membrane viability (RR = 1.00, 95% CI = 0.93-1.08, I2 = 0); ocular congestion resolution (RR = 1.11, 95% CI = 0.97-1.26, I2 = 0); fluorescent staining of amniotic membranes on the second day after the operation (RR = 1.31, 95% CI = 0.80-2.14, I2 = 11); postoperative recurrence rate (RR = 1.01, 95% CI = 0.50-2.03, I2 = 0); and premature lysis of amniotic membrane implants (RR = 0.96, 95% CI = 0.49-1.88, I2 = 0). The findings indicated that there was no statistically significant disparity between fresh and preserved amniotic membranes across any of the measured variables. There is no substantial disparity in the effectiveness of fresh and preserved amniotic membrane transplants in restoring the ocular surface, and both yield favorable and consistent outcomes.

Progranulin Facilitates Corneal Repair Through Dual Mechanisms of Inflammation Suppression and Regeneration Promotion

The cornea serves as a vital protective barrier for the eye; however, it is prone to injury and damage that can disrupt corneal epithelium and nerves, triggering inflammation. Therefore, understanding the biological effects and molecular mechanisms involved in corneal wound healing and identifying drugs targeting these pathways is crucial for researchers in this field. This study aimed to investigate the therapeutic potential of progranulin (PGRN) in treating corneal injuries. Our findings demonstrated that PGRN significantly enhanced corneal wound repair by accelerating corneal re-epithelialization and re-innervation. In vitro experiments with cultured epithelial cells and trigeminal ganglion cells further revealed that PGRN stimulated corneal epithelial cell proliferation and promoted axon growth in trigeminal ganglion cells. Through RNA-sequencing (RNA-seq) analysis and other experimental techniques, we discovered that PGRN exerted its healing effects modulating Wnt signaling pathway, which played a critical role in repairing epithelial cells and promoting axon regeneration in trigeminal neurons. Importantly, our study highlighted the anti-inflammatory properties of PGRN by inhibiting the NF-κB signaling pathway, leading to decreased infiltration of macrophages. In conclusion, our findings underscored the potential of PGRN in facilitating corneal wound healing by promoting corneal epithelial cell proliferation, trigeminal ganglion cell axon regeneration, and suppressing ocular inflammation. These results suggest that PGRN could potentially expedite the healing process and improve visual outcomes in patients with corneal injuries.

A Review of Current Uses of Amniotic Membrane Transplantation in Ophthalmic Plastic and Reconstructive Surgery

PURPOSE

To review and summarize the existing literature on the clinical applications of amniotic membrane transplantation (AMT) in ophthalmic plastic and reconstructive surgery.

METHODS

A literature review was conducted on the PubMed database using the following search terms: "amniotic membrane" and "eyelid" or "orbit" or "fornix" or "socket" or "lacrimal".

RESULTS

In total 516 articles resulted from the search, of which 62 were included. Numerous cases and case series have been published on the use of amniotic membrane transplantation for ocular surface reconstruction, eyelid and forniceal reconstruction, and cicatricial eyelid abnormalities. Surgical methods of securing the graft vary. Few comparative studies exist; some show a similar or improved result when compared to oral mucous membrane grafting for certain indications.

CONCLUSIONS

Amniotic membrane transplantation can be a useful tool for the oculoplastic surgeon when faced with a case requiring reconstruction of the posterior lamellae, particularly in patients without other graft donor sites available, and uses of AMT continue to expand. Additional studies directly comparing AMT to other reconstructive techniques would be helpful in choosing between the available surgical techniques and standardizing best practices.

Ornidazole induced Stevens-Johnson syndrome without body surface involved: A case report

RATIONALE

Ornidazole is a synthetic nitroimidazole derivative that is commonly prescribed for antiparasitic or anti-anaerobic infections. It is generally well tolerated, with known side effects including gastrointestinal tract, anaphylaxis, and central nervous system reactions. Ornidazole-induced binocular reactive keratitis and several mucocutaneous lesions have been rarely reported.

PATIENT CONCERNS

A 52-year-old woman who suffered from vaginitis and received an ornidazole vaginal plug (0.5 g). Approximately 20 minutes after the suppository was inserted into the vagina, her lips were swollen and valva and labia were burning. Her eyes were red, sore, and watery.

DIAGNOSIS

She was diagnosed as Steven-Johnson syndrome by the ophthalmologist. According to the Naranjo scale, the adverse drug reaction was evaluated to be probable and severe.

INTERVENTIONS

Dexamethasone was intravenous administrated as anti-inflammatory therapy for 10 days. Eye drops were locally given to relieve edema and promote healing of the epithelium. The symptoms of her eyes, lips, vulva and crissum were soon relieved.

OUTCOMES

The patient was discharge from hospital with improved symptoms.

LESSONS

In order to avoid severe adverse effect, the patient should not use metronidazole ether orally or vaginally. The case emphasized the importance of rapid and accurate diagnosis of Steven-Johnson syndrome induced by ornidazole vaginal plug, especially when the eye symptoms were the chief complaint without body skin involved.

Clinical Outcome of Amniotic Membrane Transplant in Ocular Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis at a Major Burn Unit

PURPOSE

To analyze the clinical outcome of amniotic membrane transplantation in patients with ocular Stevens-Johnson syndrome/toxic epidermal necrolysis at a major burn unit.

DESIGN

Retrospective, non-randomized interventional study.

METHODS

A retrospective chart review from April 2014 to January 2022 of 43 patients (85 eyes) at a burn center who underwent amniotic membrane transplantation (AMT) for severe ocular Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), or SJS/TEN was performed. Data regarding the clinical course and outcome were obtained. A comparison between the use of cryopreserved AMT rings (cryoAMT) and dehydrated AMT (deAMT) was also assessed.

RESULTS

A total of 85 eyes in 43 patients underwent AMT for severe ocular SJS/TEN. Of the eyes, 72 received deAMT with symblepharon ring, whereas 13 received cryoAMT over the cornea surface. All patients had deAMT placed over the eyelid margins and palpebral conjunctivae and tucked into the fornices. The average best-corrected visual acuity (BCVA) on last follow-up examination was 20/33, 20/30, and 20/34 in all eyes, the cryoAMT group, and the deAMT group, respectively (no significant difference between groups). The most common suspected inciting agent was lamotrigine (17% of all cases). The average long-term complication score was 1.4, with no significant difference between the cryoAMT group (1.6) and the deAMT group (1.4, P = .5). Symblepharon formation was seen more in the cryoAMT group compared to the deAMT group (P < .05).

CONCLUSION

The use of AMTs in severe ocular SJS/TEN greatly mitigates long-term complications and improves visual outcome. The retrospective nature of this study limits substantial conclusions regarding any significant difference in outcome between AMT treatment methods. Nevertheless, the use of cryopreserved AMT rings has a similar outcome profile compared to use of dehydrated AMTs with symblepharon ring. Further research is needed to evaluate optimal AMT techniques.

Self-Retained, Sutureless Amniotic Membrane Transplantation for the Management of Ocular Surface Diseases

Amniotic membrane (AM) has anti-inflammation, anti-fibrotic, and regenerative effects. Sutureless cryopreserved AM transplantation, ProKera® (Bio-Tissue, Inc., Miami, FL, USA), is easily applied by ophthalmologists in the treatment of ocular surface diseases. This retrospective study included patients with ocular surface diseases who received ProKera® between January 2022 and May 2023. Six patients (9 eyes) with a mean age of 56.8 ± 20.8 years old (range 25-74) and a mean follow-up period of 7.8 ± 4.1 months (range 1-12) were included, including 2 of recurrent conjunctival tumors with limbal and corneal involvement (cases 1-2), 1 of pterygium with marked astigmatism (case 3) and 3 of Stevens-Johnson syndrome (SJS, cases 4-6). ProKera® was inserted after the lesion excision and deep keratectomy in cases 1-3, and no recurrence or corneal complication was noted. Cases 4-5 were discharged from the intensive care unit and presented with severe chronic SJS. Most ocular manifestations improved significantly after symblepharon release and ProKera® insertion, except for corneal conjunctivalization in 1 eye (case 5). Case 6 involved early ProKera® use at the bedside during acute SJS, resulting in complete resolution. We concluded that the adjunctive application of ProKera® can be effective for ocular surface reconstruction and provides options to intervene earlier for outpatients or patients unstable for invasive surgical intervention.

Biological properties and surgical applications of the human amniotic membrane

The amniotic membrane (AM) is the inner part of the placenta. It has been used therapeutically for the last century. The biological proprieties of AM include immunomodulatory, anti-scarring, anti-microbial, pro or anti-angiogenic (surface dependent), and tissue growth promotion. Because of these, AM is a functional tissue for the treatment of different pathologies. The AM is today part of the treatment for various conditions such as wounds, ulcers, burns, adhesions, and skin injury, among others, with surgical resolution. This review focuses on the current surgical areas, including gynecology, plastic surgery, gastrointestinal, traumatology, neurosurgery, and ophthalmology, among others, that use AM as a therapeutic option to increase the success rate of surgical procedures. Currently there are articles describing the mechanisms of action of AM, some therapeutic implications and the use in surgeries of specific surgical areas, this prevents knowing the therapeutic response of AM when used in surgeries of different organs or tissues. Therefore, we described the use of AM in various surgical specialties along with the mechanisms of action, helping to improve the understanding of the therapeutic targets and achieving an adequate perspective of the surgical utility of AM with a particular emphasis on regenerative medicine.

Management of Sjogren's Dry Eye Disease-Advances in Ocular Drug Delivery Offering a New Hope

Sjögren's syndrome is a chronic and insidious autoimmune disease characterized by lymphocyte infiltration of exocrine glands. Patients typically present with dry eye, dry mouth, and other systemic manifestations. Currently, the available molecules and drug-delivery systems for the treatment of Sjögren's syndrome dry eye (SSDE) have limited efficacy since they are not specific to SSDE but to dry eye disease (DED) in general. The current treatment modalities are based on a trial-and-error approach using primarily topical agents. However, this approach gives time for the vicious cycle of DED to develop which eventually causes permanent damage to the lacrimal functional unit. Thus, there is a need for more individualized, specific, and effective treatment modalities for SSDE. The purpose of this article is to describe the current conventional SSDE treatment modalities and to expose new advances in ocular drug delivery for treating SSDE. A literature review of the pre-clinical and clinical studies published between 2016 and 2022 was conducted. Our current understanding of SSDE pathophysiology combined with advances in ocular drug delivery and novel therapeutics will allow the translation of innovative molecular therapeutics from the bench to the bedside.

The use of biological amniotic membranes in the treatment of recurrent macular holes

To evaluate the clinical therapeutic effects of a technique in which biological amniotic membranes (bAMs) are used in the treatment of patients with recurrent macular holes. In this prospective nonrandomized case series study, 23 eyes of 23 patients with recurrent macular holes who had already undergone surgery with pars plana vitrectomy with internal limiting membrane peeling were evaluated. In the surgery, a bAM was used to cover the macular area, and C₃F₈ tamponade was performed on these patients. Phacoemulsification combined with intraocular lens implantation was performed simultaneously in patients who had cataracts. Patients were followed up for at least half a year. The main outcomes were whether the macular hole closed, the morphological changes in the macular graft, the best-corrected visual acuity, intraocular pressure (IOP) and other indicators. In all eyes, the recurrent macular holes were closed. Two cases (8.69%, 2/23) had bAM shifting half a month after surgery, and these patients underwent a second surgery to adjust the position of the bAM and perform C3F8 tamponade. In the 6-month follow-up, 21 patients (91.30%, 21/23) had improved visual acuity (VA), and 2 patients (8.69%, 2/23) had no change in VA. The mean VA increased from 1.73 ± 0.32 before surgery to 1.12 ± 0.42 after surgery (t = 10.63, P = 0.00 < 0.01), and the mean IOP decreased from 22.13 ± 5.56 before surgery to 17.23 ± 1.71 after surgery (t = 5.14, P = 0.00 < 0.01). No serious complications occurred in any of the cases. The technique of using a biological amniotic membrane can be an effective treatment for patients with recurrent macular holes.

Peripheral ulcerative keratitis due to systemic diseases

PURPOSE OF REVIEW

To discuss peripheral ulcerative keratitis, with a focus on the evaluation and management of associated systemic diseases.

RECENT FINDINGS

Peripheral ulcerative keratitis (PUK) is a sight-threatening condition that is often defined by the presence of a crescent-shaped area of peripheral corneal thinning, an epithelial defect, and an inflammatory corneal infiltrate. It is highly associated with rheumatoid arthritis, systemic necrotizing vasculitides like granulomatosis with polyangiitis, and collagen vascular diseases like systemic lupus erythematosus. Undertreated PUK carries a risk of vision loss and premature death.

SUMMARY

Multidisciplinary collaboration between the ophthalmologist, rheumatologist, and other consultants is required. Early and aggressive steroid-sparing therapy should be considered in cases due to noninfectious systemic disease.