Amniotic membrane transplantation for persistent corneal epithelial defects in eyes after penetrating keratoplasty

Umbilical Cord Graft for Refractory Neurotrophic Keratopathy

PURPOSE

The purpose of this study was to evaluate whether an umbilical cord tissue graft (UCG) could promote reepithelialization in refractory cases of neurotrophic keratopathy, which failed traditional treatment modalities including amniotic membrane grafts.

METHODS

This retrospective case series included 3 eyes of 3 patients who underwent UCG placement for refractory stage 3 neurotrophic keratopathy. Records were reviewed to evaluate the clinical course including previous treatments, time to UCG dissolution, time to corneal epithelialization, and recurrence of epithelial defects.

RESULTS

The time of a nonhealing epithelial defect before UCG placement ranged from 7.7 to 30 weeks (mean 21.0). UCG dissolution time ranged from 1.7 to 8.1 weeks (mean 5.0) compared with the previous failed amniotic membrane dissolution time of 0.3 to 1.6 weeks (mean 0.95). The time to complete epithelialization after UCG placement was 7.7 and 8.1 weeks, respectively, for the first 2 cases, whereas the third case did not fully epithelialize. Only 1 eye did not have recurrence of an epithelial defect. The maximum time of maintained epithelialization without recurrence ranged from 5 to 86 weeks (mean 42.7). Follow-up time was 37 to 108.1 weeks (mean 62.2) after first UCG placement.

CONCLUSIONS

UCG may allow for longer retention time of tissue grafts, provide a mechanical barrier for protection, and aid in regeneration of the ocular surface. UCG may be an option for re-epithelialization in recalcitrant cases of neurotrophic keratopathy, after conventional treatments such as amniotic membrane grafts have failed.

Ophthalmic Aspects of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: A Narrative Review

The aim of our review article was to summarize the current literature on Stevens-Johnson syndrome (SJS) and its severe form, toxic epidermal necrolysis (TEN). SJS/TEN is a serious, rare multi-system, immune-mediated, mucocutaneous disease with a significant mortality rate that can lead to severe ocular surface sequelae and even to bilateral blindness. Restoration of the ocular surface in acute and chronic SJS/TEN is challenging. There are only limited local or systemic treatment options for SJS/TEN. Early diagnosis, timely amniotic membrane transplantation and aggressive topical management in acute SJS/TEN are necessary to prevent long-term, chronic ocular complications. Although the primary aim of acute care is to save the life of the patient, ophthalmologists should regularly examine patients already in the acute phase, which should also be followed by systematic ophthalmic examination in the chronic phase. Herein, we summarize actual knowledge on the epidemiology, aetiology, pathology, clinical appearance and treatment of SJS/TEN.

[Autologous serum eye drops for therapy-resistant epithelial defects of the cornea : Impact of underlying disease and simultaneous amniotic transplantation in 990 applications]

BACKGROUND

The aim of the study was to evaluate the impact of simultaneous amniotic membrane transplantation (AMT), status of the cornea (own cornea vs. graft) and underlying disease on the success and recurrence rates of autologous serum (AS) in therapy-resistant epithelial defects.

PATIENTS AND METHODS

Between 2007 and 2019, 990 treatments with AS in 703 eyes of 645 patients were retrospectively examined. The presence of erosion or ulcer, use of AMT, status of the cornea and the underlying disease were recorded. Epithelial closure rate within 4 weeks and the recurrence rate after epithelial closure were main outcome measures. The median observation period was 50 months.

RESULTS

Epithelial closure was seen in 73.6% and recurrence in 27.4%. AMT was used significantly more often for ulcers (p < 0.001) and recurrences (p = 0.048). Without AMT, there was a significantly higher epithelial closure rate (p < 0.001) and faster healing tendency (p < 0.001). There was no difference between own corneas and grafts with respect to epithelial closure rate (p = 0.47). On the grafts there was a significantly higher recurrence rate (p = 0.004) and faster recurrence (p = 0.03), especially ≤6 months after epithelial closure. The underlying diseases showed a significant difference in epithelial closure rate (p = 0.02) and recurrence rate (p < 0.001) with highest success in corneal dystrophies and lowest in congenital aniridia.

CONCLUSION

AS is an effective therapeutic option for therapy-resistant epithelial defects. There was a high success rate for the grafts but with a higher tendency to develop recurrences. In cases of simultaneous AMT, a reduced success rate can be expected, due to the higher complexity of the given situation. AS can be used successfully in various underlying diseases, with limitations in case of congenital aniridia.

Sutureless dehydrated amniotic membrane for persistent epithelial defects

PURPOSE

To report outcomes of a sutureless dehydrated amniotic membrane for persistent epithelial defects (PED).

METHODS

This retrospective study included consecutive patients with a PED (⩾14 days) treated with a sutureless dehydrated amniotic membrane and bandage contact lens (BCL). Included were patients with an epithelial defect that did not respond to treatment with a BCL. Excluded were patients with a follow-up time of less than 3 months.

RESULTS

Nine eyes of eight patients with a mean age of 54.6 ± 10.9 years (range 38-73 years) were included in this study. The main etiology of the PED was limbal stem cell deficiency (n = 5/9) due to Stevens-Johnson Syndrome (n = 2/5), glaucoma procedures (n = 1/5), graft-versus-host disease (n = 1/5) and severe allergic reaction (n = 1/5). Additional etiologies included neurotrophic cornea (n = 2/9), post keratoplasty and severe dry eye disease (n = 2/9). Time from PED presentation to amnion treatment was 65.9 ± 60.6 days (range 15-189 days) with the area of the PED being 11.0 ± 12.2 mm2 (range 1.0-36.0 mm2). The amnion was absorbed within 2 weeks in 100% of the cases. Following insertion of the amnion, resolution of the PED was achieved in 8/9 eyes (89%) without the need for additional interventions within 17.8 ± 9.6 days (range 7-35 days). LogMAR BCVA improved from 0.94 ± 0.88 to 0.37 ± 0.25 (p = 0.036) with no complications or recurrences recorded.

CONCLUSIONS

Sutureless dehydrated amniotic membrane achieved resolution of PEDs secondary to various etiologies in 89% of eyes with a significant improvement in vision demonstrated. Further studies are needed to assess long term safety and effectiveness.

[Anterior stromal micropuncture for the treatment of persistent corneal epithelial graft defects after penetrating keratoplasty]

Persistent corneal graft erosion or persistent epithelial corneal defect is a frequent complication of penetrating keratoplasty. Its development can be contributed by the dry eye syndrome, rare blinking, lagophthalmos, symblepharon, viral infection, autoimmune aggression, and the use of epithelial-toxic eye drops. The article presents three clinical observations of patients who developed persistent corneal graft erosion after penetrating keratoplasty. Due to the ineffectiveness of local conservative therapy for more than 3 weeks, anterior stromal corneal micropuncture was performed. After the procedure, there was a gradual epithelial proliferation, complete healing of the corneal surface was observed 10-16 days after the manipulation, the follow-up period was at least 1 year. The mechanism of action of stromal micropuncture is associated with the creation of a porous surface with better adhesion properties, as well as with the activation of the production of extracellular matrix glycoproteins such as fibronectin, type IV collagen and laminin, which are necessary for stable adhesion of the epithelium. The use of stromal micropuncture of the donor flap in the treatment of post-keratoplasty persistent corneal epithelial defect was proposed for the first time.

Sub-Regional Differences of the Human Amniotic Membrane and Their Potential Impact on Tissue Regeneration Application

For more than 100 years, the human amniotic membrane (hAM) has been used in multiple tissue regeneration applications. The hAM consists of cells with stem cell characteristics and a rich layer of extracellular matrix. Undoubtedly, the hAM with viable cells has remarkable properties such as the differentiation potential into all three germ layers, immuno-modulatory, and anti-fibrotic properties. At first sight, the hAM seems to be one structural entity. However, by integrating its anatomical location, the hAM can be divided into placental, reflected, and umbilical amniotic membrane. Recent studies show that cells of these amniotic sub-regions differ considerably in their properties such as morphology, structure, and content/release of certain bioactive factors. The aim of this review is to summarize these findings and discuss the relevance of these different properties for tissue regeneration. In summary, reflected amnion seems to be more immuno-modulatory and could have a higher reprogramming efficiency, whereas placental amnion seems to be pro-inflammatory, pro-angiogenic, with higher proliferation and differentiation capacity (e.g., chondrogenic and osteogenic), and could be more suitable for certain graft constructions. Therefore, we suggest that the respective hAM sub-region should be selected in consideration of its desired outcome. This will help to optimize and fine-tune the clinical application of the hAM.

Diabetic keratopathy: Insights and challenges

Ocular complications from diabetes mellitus are common. Diabetic keratopathy, the most frequent clinical condition affecting the human cornea, is a potentially sight-threatening condition caused mostly by epithelial disturbances that are of clinical and research attention because of their severity. Diabetic keratopathy exhibits several clinical manifestations, including persistent corneal epithelial erosion, superficial punctate keratopathy, delayed epithelial regeneration, and decreased corneal sensitivity, that may lead to compromised visual acuity or permanent vision loss. The limited amount of clinical studies makes it difficult to fully understand the pathobiology of diabetic keratopathy. Effective therapeutic approaches are elusive. We summarize the clinical manifestations of diabetic keratopathy and discuss available treatments and up-to-date research studies in an attempt to provide a thorough overview of the disorder.

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.

Amniotic membrane transplantation for managing dry eye and neurotrophic keratitis

Neurotrophic keratitis (NK), a degenerative disease caused by damage to the trigeminal nerve, abolishes both tearing and blinking reflexes, thus causing the most severe forms of dry eye disease (DED). Conversely, the increasing severity of DED also leads to progressive loss of corneal nerve density, potentially resulting in NK. Both diseases manifest the same spectrum of corneal pathologies including inflammation and corneal epithelial keratitis, which can progress into vision-threatening epithelial defect and stromal ulceration. This review summarizes the current literature regarding outcomes following sutured and sutureless cryopreserved amniotic membrane (AM) in treating DED as well as epithelial defects and corneal ulcers due to underlying NK. These studies collectively support the safety and effectiveness of cryopreserved AM in restoring corneal epithelial health, improving visual acuity in eyes with NK and DED, and alleviating symptomatic DED. Future randomized controlled trials are warranted to validate the above findings and determine whether such clinical efficacy lies in promoting corneal nerve regeneration.

A comparative study of tarsorrhaphy and amniotic membrane transplantation in the healing of persistent corneal epithelial defects

Purpose

To compare and study the clinical outcome of tarsorrhaphy and amniotic membrane transplant in the healing of persistent corneal epithelial defects in terms of clinical improvement and symptomatic relief.

Methods

This was an interventional, prospective study in which a total of 60 patients with persistent epithelial defects (PED's), randomly divided into two groups of 30 patients each who underwent tarsorrhaphy (Group A) or amniotic membrane transplantation (Group B) with a 4-week-follow-up period, were included. The main parameters studied were the size of an epithelial defect, total healing time, pain score, and complications.

Results

The study included 60 eyes of 60 patients with PED. The healing time was 9.83 ± 6.51 days in Group A (median = 9.50 days, IQR = 1-7 days) vs. 18.33 ± 13.46 days (median = 19.50 days, IQR = 1-21 days) in Group B. A total of ten eyes (16.7%) did not heal at the end of 4 weeks.

Conclusion

There was a significant reduction in the area of epithelial defect at the end of the 1 week and 2 week follow up postoperatively, in both the treatment forms. The mean healing time in patients of Group A was less as compared to that of the patients in Group B.

Autologous Platelet-rich Plasma Eye Drops Accelerate Re-epithelialization of Post-keratoplasty Persistent Corneal Epithelial Defects

Purpose:

To investigate whether autologous platelet-rich plasma (PRP) eye drops accelerate re-epithelialization of post-keratoplasty persistent corneal epithelial defects (PEDs).

Methods:

A total of 34 eyes with PEDs after keratoplasty (24 penetrating keratoplasty and 10 deep anterior lamellar keratoplasty) that were refractory to conventional medical treatments were treated with PRP eye drops every 3 hours. PRP eye drops were prepared with a low- and high-speed centrifugation method and final platelet counts were 700,000-800,000 plt/μl. The mean treatment duration for complete re-epithelialization was compared with the mean treatment duration of conventionally treated corneal defects before the PRP treatment by paired t-test. The mean treatment duration was also statistically analyzed between age groups, gender, indications for keratoplasty, and types of keratoplasty using analysis of variance (ANOVA).

Results:

Treatment with autologous PRP eye drops led to rapid re-epithelialization in all eyes. The mean treatment duration for complete re-epithelialization was 2.47 ± 1.21 weeks, which was significantly shorter than the mean treatment duration of conventionally treated corneal defects before PRP treatment (6.82 ± 1.24 weeks) (P = 0.0001). There was no significant correlation between re-epithelialization time and patients' age, sex, indications for keratoplasty, and techniques of corneal transplantation.

Conclusion:

Treatment with autologous PRP eye drops is an effective and reliable approach that accelerates re-epithelialization of post-transplantation PEDs.

"Therapeutic Penetrating Keratoplasty: A Retrospective Review"

PURPOSE

To report the indications, outcomes, and complications of therapeutic penetrating keratoplasty (Th PK) in patients with corneal perforation and/or nonhealing corneal ulceration.

METHODS

A retrospective review was conducted of 51 eyes of 51 patients undergoing Th PK between January 1, 2006 and April 15, 2016. Data collected included patient demographics, visual acuity (VA), size of the corneal infiltrate and epithelial defect, degree of corneal thinning/perforation, microbiological results, surgical details, and postoperative complications.

RESULTS

The average age at presentation was 56.0 years (range 6-92 years), and most of the patients were females (n=31, 60.8%). Th PK was performed for corneal perforation in 28 eyes (54.9% of cases), nonhealing corneal ulcer in 16 eyes (31.4% of cases), and imminent risk of corneal perforation in 7 eyes (13.7% of cases). Infection was the most common reason for performing a Th PK and was present in 92.3% (47/51) of all cases. Of the infectious cases, the most common etiologies were bacterial (44.7%, 21/47) and fungal (31.9%, 15/47). The most common identifiable risk factor for undergoing a Th PK was a history of contact lens wear, which was seen in 32.7% of patients. Initial anatomic success was achieved in all patients after performing Th PK. Most patients (33/51; 64.7%) had clear grafts at their last follow-up examination. There was an improvement in VA in 70.2% (33/47, where data were available) of the patients at the final postoperative visit compared with the preoperative visit. Average best postoperative VA (1.14±0.88 logarithm of the minimum angle of resolution [LogMAR]; 20/276) was significantly better than the presenting (1.98±0.68 LogMAR; 20/1910) and preoperative (2.18±0.55 LogMAR; 20/3,027) visual acuities (P<0.0001). The most common complication after Th PK was cataract, which was present in 81.8% (27/33) of phakic eyes in which lens status could be assessed, followed by graft failure (47.1%; 24/51), and secondary glaucoma (45.1%; 23/51). Five eyes developed infection in the therapeutic graft, four eyes had persistent corneal epithelial defect at their last follow-up visit, and two eyes underwent evisceration.

CONCLUSIONS

Therapeutic penetrating keratoplasty achieves anatomic success and it is a useful procedure for restoring a stable cornea in cases in which infection fails to heal or when the cornea perforates. Furthermore, Th PK achieves corneal clarity and improves vision in most patients.

Simultaneous penetrating keratoplasty and amniotic membrane transplantation in eyes with a history of limbal stem cell deficiency

PURPOSE

To describe the outcomes of simultaneous penetrating keratoplasty (PK) and amniotic membrane transplantation (AMT) performed both as a ring-shaped graft and as a temporary patch in eyes with a history of limbal stem cell deficiency (LSCD).

METHODS

Prospective observational case series including 48 simultaneous PK/AMT procedures (48 patients) in eyes with a history of partial or total LSCD. Patients with total LSCD were first treated with limbal stem cell transplantation. The preoperative indication was graft failure in 58.3% of cases. Most recipients (89.6%) were at high-risk for rejection.

RESULTS

The mean graft reepithelialization time was 29.2±30.8 days. Graft reepithelialization was achieved in 30 days in 70.8% of cases. No AMT-related adverse events were observed. The mean time from keratoplasty-to-last visit was 84.5±54.5 months. The 3-year graft survival rate was 62.5%. Recurrence of corneal epithelial defects after graft reepithelialization (47.9%) was associated with lower graft survival (P=0.004). In eyes with successful grafts at the last visit, the mean LogMAR visual acuity was 1.90 (20/1575)±5 lines before keratoplasty and 0.89 (20/155)±10 lines at 5 years. A ring of amniotic membrane was visible between the graft stroma and the corneal epithelium on slit-lamp examination and optical coherence tomography in all successful cases.

CONCLUSIONS

In this series of eyes with a history of LSCD and at high-risk of rejection, simultaneous PK and AMT were associated with satisfactory graft survival and no additional adverse events.

Recalcitrant Atopic Keratoconjunctivitis in Children: A Case Report and Literature Review

Atopic keratoconjunctivitis (AKC) is the most severe type of allergic conjunctivitis and may eventually lead to blindness. Although AKC is reported to be more prevalent in adults, we report a child with AKC whose clinical characteristics were not inconsistent with those typically seen in adult patients with AKC, and who was refractory to traditional topical anti-inflammatory and immunosuppressant therapies. An 11-year-old boy presented with a 3-month history of ocular redness and itching and decreased vision for a week in both eyes. Slit-lamp examination revealed typical signs of vernal keratoconjunctivitis, including cobblestone papillae in both upper conjunctiva, superficial punctate keratopathy on the right cornea, and a sterile shield-shaped ulcer on the left cornea. Physical examination revealed eczematous lid changes and a generalized body rash, particularly on the face, neck, and flexor surfaces of the limbs. He was diagnosed to have AKC in both eyes and atopic dermatitis. The patient did not respond well to conventional topical antihistamine, mast cell stabilizers, corticosteroids, or tacrolimus, even in combination with amniotic membrane transplant. After using systemic immunosuppressants, the symptoms were relieved; the inflammation on the skin and ocular surface subsided, the cobblestone papillae disappeared, and the corneal ulcer healed gradually within 8 weeks. This case reveals that pediatric AKC should be differentiated from vernal keratoconjunctivitis because both disorders include upper cobblestone papillae, but the former is accompanied by atopic dermatitis. Pediatric AKC requires appropriate and aggressive treatment to prevent sight-threatening corneal complications. Systemic immunosuppressant should be considered when traditional topical anti-inflammatory therapies have failed.

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.

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.

A study protocol for a multicentre randomised clinical trial evaluating the safety and feasibility of a bioengineered human allogeneic nanostructured anterior cornea in patients with advanced corneal trophic ulcers refractory to conventional treatment

INTRODUCTION

There is a need to find alternatives to the use of human donor corneas in transplants because of the limited availability of donor organs, the incidence of graft complications, as well as the inability to successfully perform corneal transplant in patients presenting limbal deficiency, neo-vascularized or thin corneas, etc. We have designed a clinical trial to test a nanostructured fibrin-agarose corneal substitute combining allogeneic cells that mimics the anterior human native cornea in terms of optical, mechanical and biological behaviour.

METHODS AND ANALYSIS

This is a phase I-II, randomised, controlled, open-label clinical trial, currently ongoing in ten Spanish hospitals, to evaluate the safety and feasibility, as well as clinical efficacy evidence, of this bioengineered human corneal substitute in adults with severe trophic corneal ulcers refractory to conventional treatment, or with sequelae of previous ulcers. In the initial phase of the trial (n=5), patients were sequentially recruited, with a safety period of 45 days, receiving the bioengineered corneal graft. In the second phase of the trial (currently ongoing), subjects are block randomised (2:1) to receive either the corneal graft (n=10), or amniotic membrane (n=5), as the control treatment. Adverse events, implant status, infection signs and induced neovascularization are evaluated as determinants of safety and feasibility of the bioengineered graft (main outcomes). Study endpoints are measured along a follow-up period of 24 months, including 27 post-implant assessment visits according to a decreasing frequency. Intention to treat, and per protocol, and safety analysis will be performed.

ETHICS AND DISSEMINATION

The trial protocol received written approval by the corresponding Ethics Committee and the Spanish Regulatory Authority and is currently recruiting subjects. On completion of the trial, manuscripts with the results of phases I and II of the study will be published in a peer-reviewed journal.

TRIAL REGISTRATION

CT.gov identifier: NCT01765244 (Jan2013). EudraCT number: 2010-024290-40 (Dec2012).

Amniotic Membrane Transplantation for the Treatment of Infectious Ulcerative Keratitis Before Elective Penetrating Keratoplasty

PURPOSE

Emergency keratoplasties for inflamed eyes are considered to have a worse prognosis because of immunologic graft rejection. Amniotic membranes have antiinflammatory and antiangiogenic abilities. Therefore, amniotic membrane transplantation (AMT) was performed to stabilize the situation of eyes with severe infectious keratitis before elective penetrating keratoplasty (PK).

METHODS

Retrospective, nonrandomized observational case series. Seven to 41 days (median, 20 days) after the onset of intensive antiinfectious medication, an AMT (6 multigrafts and 6 sandwich) was performed in 12 patients [8 men and 4 women; age 46-80 years (median, 66 years)] with herpetic (n = 5), bacterial keratitis (n = 3), or combinations (n = 4). Three to 12 months (median, 5 months) after cessation of the inflammatory status of the eye, a central elective PK (diameter, 7-8 mm) became feasible in 10 eyes. Follow-up ranged from 4 to 38 months (median, 20 months) after PK.

RESULTS

The primary success rate of AMT was 11/12 (92%). Five recurrences (41%) were treated successfully 4 times by repeat AMT (sandwich) and 1 time by emergency PK. In 2 of the 12 eyes, an irreversible endothelial immunologic graft reaction appeared 18 and 21 months after PK. One eye suffered from reversible recurrence of herpetic keratitis on the corneal graft. At the end of the follow-up, 10 of 12 grafts (83%) were clear.

CONCLUSIONS

A rapid decrease in the inflammatory reaction and a fast reepithelialization because of AMT after intensive antiinfectious medication in case of severe ulcerative keratitis may help to avoid an emergency keratoplasty and improves the prognosis of the elective keratoplasty.

Novel Therapy to Treat Corneal Epithelial Defects: A Hypothesis with Growth Hormone

Impaired corneal wound healing that occurs with ocular surface disease, trauma, systemic disease, or surgical intervention can lead to persistent corneal epithelial defects (PCED), which result in corneal scarring, ulceration, opacification, corneal neovascularization, and, ultimately, visual compromise and vision loss. The current standard of care can include lubricants, ointments, bandage lenses, amniotic membranes, autologous serum eye drops, and corneal transplants. Various inherent problems exist with application and administration of these treatments, which often may not result in a completely healed surface. A topically applicable compound capable of promoting corneal epithelial cell proliferation and/or migration would be ideal to accelerate healing. We hypothesize that human growth hormone (HGH) is such a compound. In a recent study, HGH was shown to activate signal transducer and activators of transcription-5 (STAT5) signaling and promote corneal wound healing by enhancing corneal epithelial migration in a co-culture system of corneal epithelial cells and fibroblasts. These effects require an intact communication between corneal epithelia and fibroblasts. Further, HGH promotes corneal wound healing in a rabbit debridement model, thus demonstrating the effectiveness of HGH in vivo as well. In conclusion, HGH may represent an exciting and effective topical therapeutic to promote corneal wound healing.

The destructive effects of antibiotics on the amniotic membrane ultrastructure

The aim of the study was to examine the influence of different antibiotics on amniotic membrane epithelium and to observe the related ultrastructural changes using transmission electron microscope (TEM). Prospective comparative laboratory study. Amniotic membrane samples from a single placenta were obtained using a sterilized method. Tissue samples were placed in either saline or antibiotics-containing (penicillin, streptomycin, neomycin, or amphotericin B) solutions. The viability of the amniotic membrane epithelial cells was then assessed for saline and antibiotics using both light microscope and TEM to investigate morphological changes. The ultrastructural examination of amniotic membrane epithelium held in antibiotics-containing solutions showed damage to the cell membrane, rarefaction, and loss of microvilli. Amniotic membrane from the control group showed intact epithelium, with surface microvilli and junctional complexes between the cells and the basal membrane. The destructive effects of antibiotics on freshly obtained amniotic membrane were examined with both light microscopy and transmission electron microscopy and significant differences in the ultrastructure were observed.

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.

Surgical treatment of 32 cases of long-term atopic keratoconjunctivitis using the amniotic membrane

PURPOSE

To evaluate the use of surgical treatment with amniotic membrane for long-term atopic keratoconjunctivitis. Damaged corneas were repaired with various techniques: amniotic membrane transplantations, amniotic membrane coverings, amniotic membrane fillings (AMFs), and amniotic membrane inlay fillings, the latter of which were combined with glycerol-preserved corneal transplants.

METHODS

This retrospective study was conducted on 37 eyes belonging to 37 patients with atopic keratoconjunctivitis. Thirty-two patients were classified into four groups according to surgical technique. Five patients undergoing medical management served as controls. Surgical outcome was measured by recovery time and long-term visual improvement.

RESULTS

In all surgical eyes, integrity of ocular tissues was effectively restored and symptoms were reduced at 24.4 ± 13 days post recovery. Mean best-corrected visual acuity improved from 0.6 ± 0.2 to 0.198 ± 0.16 logarithm of the minimum angle of resolution (P<0.001). There were no intraoperative or postoperative complications, with the exception of two recurring cases, both controlled by medication. Recovery time of the control groups lasted 52 ± 16 days. In controls, mean best-corrected visual acuity improved from 0.74 ± 0.15 to 0.54 ± 0.29 logarithm of the minimum angle of resolution (P ≤ 0.05). The vision improvement has significant difference for surgical treatment vs medical. (Mann-Whitney U-test, U = 119, P < 0.05, one tailed).Vision improvements remained stable during a mean follow-up period of 21.7 ± 3.8 months.

CONCLUSION

Patients suffering from severe chronic atopic keratoconjunctivitis and its complications can benefit from suitable surgical treatments: transplants, covers, fillings, or corneal graft surgeries supplemented with AMFs.

Management of trachomatous keratopathy by automated lamellar therapeutic keratoplasty

PURPOSE

To evaluate the efficacy of automated lamellar therapeutic keratoplasty (ALTK) for the management of anterior corneal stromal scarring caused by trachoma.

METHODS

Seventeen cases of trachomatous keratopathy that were treated by ALTK were retrospectively evaluated. The main outcome measures were uncorrected visual acuity, best-corrected visual acuity (BCVA), keratometry, pachymetry, time to epithelialization, graft clarity, and complications, if any.

RESULTS

The mean age of the patients was 50.3 ± 14.1 years. Five of the 17 cases had Salzmann nodular degeneration. The mean decimal BCVA was 0.06 ± 0.05 preoperatively, which improved to 0.41 ± 0.16 at 12 months, and 12 eyes (70.6%) had a postoperative BCVA of 6/18 or better. The median epithelialization time was 6 days (range, 1-38 days). Persistent epithelial defect developed in 6 eyes, and 1 eye developed graft infection.

CONCLUSIONS

Anterior stromal corneal scarring caused by trachoma can be effectively treated with ALTK. However, occurrence of persistent epithelial defects may complicate the success of this surgery.

Study of self-made freeze-dried bilayered fibrin-binding amniotic membrane in ocular trabeculectomy in rabbits

AIM

To investigate the antifibrotic effect of freeze-dried bilayered fibrin-binding amniotic membrane on trabeculectomy in a rabbit model.

METHODS

Twenty-four Japanese white rabbits were randomized into three groups: the experimental group (ocular trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane transplantation), the control group (ocular trabeculectomy in combination with natural bilayered fibrin-binding amniotic membrane) and the blank group (single trabeculectomy). Clinical observation, hematoxylin-eosin staining, Massion staining, real-time PCR and immunohistochemistry for α-SMA were performed on days 7, 14, 21 and 30 following surgery.

RESULTS

Statistical differences were noted in survival analysis and intraocular pressure (IOP) among groups on days 7, 14, 21 and 30 following surgery. Histology, immunohistochemistry and real-time PCR further demonstrated that trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane resulted in good wound healing and no scar formation.

CONCLUSION

Self-made freeze-dried bilayered fibrin-binding amniotic membrane may inhibit the formation of scarring in glaucoma after trabeculectomy.

The effect of topical autologous serum on graft re-epithelialization after penetrating keratoplasty

PURPOSE

To analyze factors influencing corneal graft re-epithelialization after penetrating keratoplasty (PK) and evaluate the effect of topical autologous serum in promoting graft re-epithelialization.

DESIGN

Prospective interventional study.

METHODS

We analyzed 165 eyes of 165 patients who underwent PK between January 1, 2005 and December 31, 2007. Patients were divided into 2 groups according to routine use or non-use of postoperative 20% topical autologous serum. Postoperative slit-lamp examination after fluorescein staining was performed, and graft re-epithelialization time was recorded. Recipient/donor characteristics, surgical variables, and topical use of autologous serum were analyzed for their effects on post-PK graft re-epithelialization. Statistical analysis was performed by univariate and multivariate regression analysis using the ordinal logistic fit model to assess the potential risk factors influencing graft re-epithelialization after PK.

RESULTS

In univariate analysis, diabetes mellitus (DM), longer death-to-storage time and death-to-surgery time of the donor, and larger recipient size significantly delayed graft re-epithelialization (P < .05). Use of autologous serum significantly expedited graft re-epithelialization (P = .004). In multiple regression analysis, only DM in the recipient (odds ratio [OR] = 5.10, P < .001), postoperative use of autologous serum (OR = 0.54, P = .046), and larger graft size (OR = 4.44, P < .001) influenced graft re-epithelialization. The beneficial and healing effect of autologous serum is particularly significant in diabetic recipients and larger grafts.

CONCLUSIONS

Several factors may influence graft re-epithelialization after PK. Graft re-epithelialization time was longer in diabetic recipients and larger grafts. Use of autologous serum may be a beneficial strategy in these patients with potentially delayed epithelial healing.