Limbal Stem Cell Deficiency after Topical Mitomycin C Therapy for Primary Acquired Melanosis with Atypia

Cell therapy in the cornea: The emerging role of microenvironment

The cornea is an ideal testing field for cell therapies. Its highly ordered structure, where specific cell populations are sequestered in different layers, together with its accessibility, has allowed the development of the first stem cell-based therapy approved by the European Medicine Agency. Today, different techniques have been proposed for autologous and allogeneic limbal and non-limbal cell transplantation. Cell replacement has also been attempted in cases of endothelial cell decompensation as it occurs in Fuchs dystrophy: injection of cultivated allogeneic endothelial cells is now in advanced phases of clinical development. Recently, stromal substitutes have been developed with excellent integration capability and transparency. Finally, cell-derived products, such as exosomes obtained from different sources, have been investigated for the treatment of severe corneal diseases with encouraging results. Optimization of the success rate of cell therapies obviously requires high-quality cultured cells/products, but the role of the surrounding microenvironment is equally important to allow engraftment of transplanted cells, to preserve their functions and, ultimately, lead to restoration of tissue integrity and transparency of the cornea.

Safety and efficacy of topical interferon alpha 2B and mitomycin C for localized conjunctival intraepithelial neoplasia: long-term report of their pharmacological safety and efficacy

PURPOSE

Ocular surface squamous neoplasia (OSSN) comprises a wide spectrum of squamous tumors, from which corneal/conjunctival intraepithelial neoplasia (CIN) is the most common one. The classic treatment is complete excision, but recurrence rates are high. Antineoplastic drugs such as mitomycin C (MMC) and interferon alpha 2b (IFNα2b) have been used as adjuvants or as primary treatment. To evaluate the efficacy and safety of topical IFNα2b and MMC in patients with CIN, a phase IIb double-blind clinical trial was performed.

METHODS

Patients diagnosed with localized CIN were evaluated by slit lamp and impression cytology and were randomly given MMC 0.04% or INF2b (1 million IU/mL) 4 times daily until neoplasia resolution. Time of resolution and frequency of adverse effects were analyzed to determine the pharmacological efficacy and safety of both medications.

RESULTS

Seventeen patients were included. Nine patients were treated with MMC and 8 with IFNα2b. All patients responded to treatment. The resolution time in days was 59.11 ± 24.02 in patients treated with MMC and 143.50 ± 47.181 in those treated with IFNα2b (p < 0.001). In the MMC group, one recurrence was reported (11%). There were no recurrences at 2 years of follow-up in the IFNα2b group. Regarding adverse effects, one or more mild adverse reaction occurred in 77% of patients managed with MMC and in 50% of patients managed with IFNα2b (p > 0.05). No serious adverse effects were reported.

CONCLUSIONS

Topical chemotherapy with MMC and IFNα2b demonstrate pharmacological safety and efficacy. Therefore, these drugs could be considered as primary therapies for localized CIN .

[Bottlenecks in the availability of ophthalmological medications : Initiative of the Working Group on Ethics in Ophthalmology of the DOG and the University Eye Clinic Bonn]

BACKGROUND

Bottlenecks in drug supply in the field of ophthalmological are continuously increasing in Germany. So far, these have hardly been communicated and discussed. We see the transparent presentation of the problem as a first step in compiling concepts to counteract this development.

AIM OF THE WORK

Presentation of the supply shortages in ophthalmological drugs.

MATERIAL AND METHODS

A listing and discussion of the shortages in drug supply to the best of our knowledge are presented.

RESULTS

We distinguish between the problems in (1) supply shortages, (2) discontinuation of production, (3) lack of availability in Germany and (4) manufacture of drugs in specialized pharmacies often lacking approval for the ophthalmological indications.

DISCUSSION

The reasons for drug supply shortages in ophthalmology are complex and therefore no easy solutions can be expected; however, industrial and regulatory authorities at the national and European levels are called upon to analyze the underlying problems and to find appropriate solutions.

Profile of biological characterizations and clinical application of corneal stem/progenitor cells

Corneal stem/progenitor cells are typical adult stem/progenitor cells. The human cornea covers the front of the eyeball, which protects the eye from the outside environment while allowing vision. The location and function demand the cornea to maintain its transparency and to continuously renew its epithelial surface by replacing injured or aged cells through a rapid turnover process in which corneal stem/progenitor cells play an important role. Corneal stem/progenitor cells include mainly corneal epithelial stem cells, corneal endothelial cell progenitors and corneal stromal stem cells. Since the discovery of corneal epithelial stem cells (also known as limbal stem cells) in 1971, an increasing number of markers for corneal stem/progenitor cells have been proposed, but there is no consensus regarding the definitive markers for them. Therefore, the identification, isolation and cultivation of these cells remain challenging without a unified approach. In this review, we systematically introduce the profile of biological characterizations, such as anatomy, characteristics, isolation, cultivation and molecular markers, and clinical applications of the three categories of corneal stem/progenitor cells.

Topical pharmacotherapy for ocular surface squamous neoplasia: systematic review and meta-analysis

Ocular surface squamous neoplasia (OSSN) has different treatment modalities. Although surgical excision has been the gold standard therapeutic option, topical pharmacotherapy agents such as 5-fluorouracil (5-FU), interferon alfa-2b (IFN) and mitomycin-C (MMC) are also commonly used. The protocol was registered (CRD42021224961). Comprehensive literature research was carried out to compare topical pharmacotherapy (5-FU or IFN or MMC) to surgical excision regarding clinical success (tumor resolution), recurrence and complications in patients undergoing treatment for OSSN. From 7859 records, 7 articles were included in the qualitative and 4 in the quantitative synthesis. The outcomes of surgical excision and topical pharmacotherapy were comparable in the included articles. There were no significant differences between surgical excision and topical pharmacotherapy regarding the clinical success [odds ratio (OR): 0.785; confidence interval (CI): 0.130–4.736, P = 0.792)] and tumor recurrence (OR: 0.746; CI: 0.213–2.609; P = 0.646). The most common side effect of the different therapeutic options was dry eye. The highest rate of dry eye symptoms was reported after surgical excision (in 59%). Topical pharmacotherapy with all the 3 agents is as effective and well-tolerable as surgical excision in terms of tumor resolution, recurrence rate and side effects in all OSSN patients suggesting similar long-term clinical benefits.

Inhibition of enhancer of zeste homolog 2 prevents corneal myofibroblast transformation in vitro

PURPOSE

Corneal fibroblast can be transformed into corneal myofibroblasts by TGF-β1. Enhancer of zeste homolog 2 (EZH2) upregulation has been observed in the occurrence of other fibrotic disorders. We investigated the role of EZH2 in the progression of corneal fibrosis and the antifibrotic effect of EZH2 inhibition in corneal fibroblasts (CFs).

METHODS

Primary CFs were isolated from corneal limbi and the CFs were treated with TGF-β1 to induce fibrosis. EPZ-6438 and EZH2 siRNA were used to inhibit EZH2 expression. Myofibroblast activation and extracellular matrix (ECM) protein synthesis was detected by quantitative real-time PCR, western blotting, and immunofluorescence staining assay. The functions of myofibroblast were evaluated by cell migration and collagen gel contraction assays. Molecular mechanisms involved in EZH2 inhibition were investigated by RNA sequencing.

RESULTS

TGF-β1 activated EZH2 expression in CFs. Treatment with EPZ-6438 (5 μM) and EZH2 siRNA considerably suppressed corneal myofibroblast activation and ECM protein synthesis in CFs induced by TGF-β1 when compared to the control group. EPZ-6438 (5 μM) suppressed cell migration and gel contraction in CFs. RNA sequencing results revealed that antifibrotic genes were activated after EZH2 inhibition to suppress corneal myofibroblast activation.

CONCLUSION

Inhibition of EZH2 suppresses corneal myofibroblast activation and ECM protein synthesis, and could serve as a novel therapeutic target for preventing corneal scarring.

Iatrogenic Ocular Surface Diseases Occurring during and/or after Different Treatments for Ocular Tumours

Simple Summary

The ocular surface represents a finely regulated system that allows the protection of the eye. It can be affected by therapies used for the treatment of various intraocular tumours, particularly conjunctival cancers and uveal melanoma. In these conditions, treatments are chosen according to the characteristics of the lesion, and include a combination of selective surgery, anticancer eye drops, and/or radiotherapy delivered through different mechanisms. Possible side effects affecting the ocular surface range from transient dry eye or keratitis up to more severe complications such as corneal melting and perforation. These complications deserve careful evaluation for the risk of permanent sight-threatening sequelae. Physicians involved in the management of patients affected by ocular tumours should be aware of this risk in order to reach an early diagnosis and promptly set up an adequate treatment. The present review summarizes acute and chronic complications affecting the ocular surface following different therapies for the treatment of conjunctival cancers and uveal melanoma, and also reports clinical cases of representative patients who experienced these complications.

Abstract

The ocular surface represents a finely regulated system that allows the protection of the eye. It is particularly susceptible to different treatments for intraocular tumours, such as uveal melanoma and conjunctival cancers. Traditionally, the management of ocular tumours depends on the characteristics of the lesion, and is based on a combination of selective surgery, topical chemotherapy, and/or radiotherapy delivered through different mechanisms (e.g., charged-particle radiotherapy or brachytherapy). Possible complications involving the ocular surface range from transient dry eye disease or keratitis up to corneal melting and perforation, which in any case deserve careful evaluation for the risk of permanent sigh-threatening complications. Clinicians involved in the management of these patients must be aware of this risk, in order to reach an early diagnosis and promptly set up an adequate treatment. The present review of the literature will summarize acute and chronic complications affecting the ocular surface following different therapies for the treatment of ocular tumours.

Timolol induces necroptosis, apoptosis and senescence concentration-dependently in rabbit Limbal stem cells in vitro

Limbal stem cells (LSCs) are crucial for corneal transparency and vision. Any damages to LSCs might lead to limbal stem cell deficiency resulting in corneal opacification and even blindness. Here, we investigated the cytotoxicity of timolol and its underlying mechanisms in rabbit LSCs (rLSCs) in vitro. High concentrations of 0.5% and 0.25% timolol induced necroptosis in rLSCs to upregulate receptor interacting protein kinase (RIPK)1, RIPK3, mixed lineage kinase domain-like (MLKL) and phosphorylated MLKL along with downregulation of caspase-8 and caspase-2 within 4 h. While, median concentrations of 0.125% to 0.0625% timolol induced apoptosis in the rLSCs within 28 h. The apoptotic mechanism in the median-concentration timolol-treated rLSCs is probably via extrinsic apoptosis pathway by activating caspase-2, caspase-8 and caspase-3 and intrinsic apoptosis pathway triggered by excessive generation of ROS and subsequent DNA damage to upregulate Bax and Bad, downregulate Bcl-2 and Bcl-xL, subsequently disrupt mitochondrial membrane potential, cytosolically translocate cytochrome c and apoptosis-inducing factor, and activate caspase-9. In addition, low concentration of 0.03125% timolol induced senescence in the rLSCs by elevating ROS level and increasing number of senescence associated β-galactosidase positive cells at 28 h. Our findings reveal that timolol induces necroptosis, apoptosis and senescence concentration-dependently in rLSCs in vitro.

Limbal Stem Cell Deficiency After Glaucoma Surgery

PURPOSE

To characterize the clinical presentation of limbal stem cell deficiency (LSCD) associated with glaucoma surgeries.

METHODS

This is a retrospective cross-sectional study of patients with LSCD and glaucoma who presented to the Stein Eye Institute at the University of California, Los Angeles, between 2009 and 2018. Patients who underwent trabeculectomy and/or aqueous shunt surgery were included. The severity of LSCD was staged using global consensus guidelines and a clinical scoring system, and basal epithelial cell density was measured by in vivo confocal microscopy. Anatomic locations of glaucoma and non-glaucoma surgeries, locations of LSCD, and severity of LSCD were compared.

RESULTS

Fifty-one eyes of 41 patients with LSCD associated with glaucoma surgery were included in this study. LSCD in these patients uniquely featured sectoral replacement of corneal epithelium by conjunctival epithelium, without corneal neovascularization or pannus. The sites of glaucoma surgery strongly correlated with the locations of LSCD (P = 0.002). There was a trend toward increased severity of LSCD in eyes with 2 or more glaucoma surgeries as compared to eyes with 1 glaucoma surgery, although the difference did not reach statistical significance (P = 0.3). Use of topical glaucoma medications correlated with LSCD severity, while the impact of antimetabolites did not reach statistical significance. The location of glaucoma drainage surgery is correlated with the location of LSCD.

CONCLUSIONS

LSCD associated with glaucoma surgery has clinical features distinct from LSCD resulting from other etiologies. Further study is required to delineate the full impact of glaucoma surgery on limbal stem cell function and survival.

Safety and efficacy of combination of suberoylamilide hydroxyamic acid and mitomycin C in reducing pro-fibrotic changes in human corneal epithelial cells

Corneal haze post refractive surgery is prevented by mitomycin c (MMC) treatment though it can lead to corneal endothelial damage, persistent epithelial defects and necrosis of cells. Suberanilohydroxamic acid (SAHA) however has been proposed to prevent corneal haze without any adverse effects. For clinical application we have investigated the short and long term outcome of cells exposed to SAHA. Human donor cornea, cultured limbal epithelial cells, corneal rims and lenticules were incubated with SAHA and MMC. The cells/tissue was then analyzed by RT-qPCR, immunofluorescence and western blot for markers of apoptosis and fibrosis. The results reveal that short term exposure of SAHA and SAHA + MMC reduced apoptosis levels and increased αSMA expression compared to those treated with MMC. Epithelial cells derived from cultured corneal rim that were incubated with the MMC, SAHA or MMC + SAHA revealed enhanced apoptosis, reduced levels of CK3/CK12, ∆NP63 and COL4A compared to other treatments. In SAHA treated lenticules TGFβ induced fibrosis was reduced. The results imply that MMC treatment for corneal haze has both short term and long term adverse effects on cells and the cellular properties. However, a combinatorial treatment of SAHA + MMC prevents expression of corneal fibrotic markers without causing any adverse effect on cellular properties.

Understanding cornea epithelial stem cells and stem cell deficiency: Lessons learned using vertebrate model systems

Animal models have contributed greatly to our understanding of human diseases. Here, we focus on cornea epithelial stem cell (CESC) deficiency (commonly called limbal stem cell deficiency, LSCD). Corneal development, homeostasis and wound healing are supported by specific stem cells, that include the CESCs. Damage to or loss of these cells results in blindness and other debilitating ocular conditions. Here we describe the contributions from several vertebrate models toward understanding CESCs and LSCD treatments. These include both mammalian models, as well as two aquatic models, Zebrafish and the amphibian, Xenopus. Pioneering developments have been made using stem cell transplants to restore normal vision in patients with LSCD, but questions still remain about the basic biology of CESCs, including their precise cell lineages and behavior in the cornea. We describe various cell lineage tracing studies to follow their patterns of division, and the fates of their progeny during development, homeostasis, and wound healing. In addition, we present some preliminary results using the Xenopus model system. Ultimately, a more thorough understanding of these cornea cells will advance our knowledge of stem cell biology and lead to better cornea disease therapeutics.

Ocular surface complications of local anticancer drugs for treatment of ocular tumors

Local chemotherapy is increasingly used, either in combination with surgery or as monotherapy, for management of ocular tumors. Yet many of the local chemotherapeutic agents used for ocular tumors are cytotoxic drugs that are frequently associated with toxicities in normal ocular tissues. Understanding and managing these side effects are important because they affect treatment tolerability, outcome and quality of vision. Herein, we review local anticancer drugs administered for the treatment of ocular tumors, with an emphasis on their toxicities to the ocular surface, adnexa and lacrimal drainage system. We provide the underlying mechanisms and management strategies for the ocular side effects. Recent innovations in anticancer immunotherapy and ocular drug delivery systems also are discussed as new potential therapeutic modalities for alleviation of side effects.

Corneal Epithelial Findings in Patients with Multiple Myeloma Treated with Antibody-Drug Conjugate Belantamab Mafodotin in the Pivotal, Randomized, DREAMM-2 Study

INTRODUCTION

Patients with relapsed or refractory multiple myeloma (RRMM) represent an unmet clinical need. Belantamab mafodotin (belamaf; GSK2857916) is a first-in-class antibody-drug conjugate (ADC; or immunoconjugate) that delivers a cytotoxic payload, monomethyl auristatin F (MMAF), to myeloma cells. In the phase II DREAMM-2 study (NCT03525678), single-agent belamaf (2.5 mg/kg) demonstrated clinically meaningful anti-myeloma activity (overall response rate 32%) in patients with heavily pretreated disease. Microcyst-like epithelial changes (MECs) were common, consistent with reports from other MMAF-containing ADCs.

METHODS

Corneal examination findings from patients in DREAMM-2 were reviewed, and the clinical descriptions and accompanying images (slit lamp microscopy and in vivo confocal microscopy [IVCM]) of representative events were selected. A literature review on corneal events reported with other ADCs was performed.

RESULTS

In most patients receiving single-agent belamaf (72%; 68/95), MECs were observed by slit lamp microscopy early in treatment (69% had their first event by dose 4). However, IVCM revealed hyperreflective material. Blurred vision (25%) and dry eye (15%) were commonly reported symptoms. Management of MECs included dose delays (47%)/reductions (25%), with few patients discontinuing due to MECs (1%). The first event resolved in most patients (grade ≥2 MECs and visual acuity [each 77%], blurred vision [67%], and dry eye [86%]), with no reports of permanent vision loss to date. A literature review confirmed that similar MECs were reported with other ADCs; however, event management strategies varied. The pathophysiology of MECs is unclear, though the ADC cytotoxic payload may contribute to on- or off-target effects on corneal epithelial cells.

CONCLUSION

Single-agent belamaf represents a new treatment option for patients with RRMM. As with other ADCs, MECs were observed and additional research is warranted to determine their pathophysiology. A multidisciplinary approach, involving close collaboration between eye care professionals and hematologist/oncologists, is needed to determine appropriate diagnosis and management of these patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier, NCT03525678.

The treatment of recurrent conjunctival and corneal intraepithelial neoplasia with interferon alfa-2b and retinoic acid: ~9 years' follow-up on tumor control

PURPOSE

To evaluate the long-term follow-up of recurrent conjunctival and corneal intraepithelial neoplasia (CCIN) treated with combination topical interferon alfa-2b and retinoic acid (I/RA).

METHODS

Our study represents a retrospective observational interventional series of 82 eyes from 82 patients from a single institution, reviewed for CCIN. All were administered topical interferon alfa-2b 1 million IU/mL QID and retinoic acid 0.01% every other day. Patients had been diagnosed by biopsy. A Kaplan-Meier survival analysis, Wilcoxon signed-rank test and a multivariate logistic regression were statistical tests used to correlate recurrence with patient and tumor variables.

RESULTS

79 eyes assessed for CCIN diagnoses and treated with I/RA achieved tumor resolution. The median tumor-free follow-up was ~109.1 months with a median time to resolution being ~2.8 months. Our median treatment duration was ~11.3 months. The greatest difference in the mean total residual tumor size was identified between Months 0-1 [-7.63 mm²]. The difference in mean total residual tumor size remained significant till 36-months. A statistically significant correlation with recurrence was identified for biopsy type [OR 0.138]. 6 patients experienced papillary conjunctivitis which resolved with dosage reduction.

CONCLUSIONS

Combination I/RA was effective in treating CCIN lesions with few transient side effects. The combination of retinoids and interferons may represent a viable topical therapeutic agent with an extended tumor-free follow-up and a large proportion of our study's patients achieving >10 year's tumor-free follow-up. Our treatment duration is long, but by cost-comparing surgical against medical interventions, topical I/RA may serve as a safe and effective alternative.

Transient Mitomycin C-treatment of human corneal epithelial cells and fibroblasts alters cell migration, cytokine secretion, and matrix accumulation

A single application of Mitomycin C (MMC) is used clinically in ophthalmology to reduce scarring and enhance wound resolution after surgery. Here we show in vitro that a 3-hour MMC treatment of primary and telomerase immortalized human corneal limbal epithelial (HCLE) cells impacts their migration and adhesion. Transient MMC treatment induces HCLE expression of senescence associated secretory factors, cytokine secretion, and deposition of laminin 332 for several days. Transient MMC treatment also reduces migration and deposition of transforming growth factor-β1 (TGFβ1)-stimulated collagen by corneal fibroblasts. Using conditioned media from control and MMC treated cells, we demonstrate that factors secreted by MMC-treated corneal epithelial cells attenuate collagen deposition by HCFs whereas those secreted by MMC-treated HCFs do not. These studies are the first to probe the roles played by corneal epithelial cells in reducing collagen deposition by corneal fibroblasts in response to MMC.

Global Consensus on Definition, Classification, Diagnosis, and Staging of Limbal Stem Cell Deficiency

PURPOSE

Despite extensive knowledge gained over the last 3 decades regarding limbal stem cell deficiency (LSCD), the disease is not clearly defined, and there is lack of agreement on the diagnostic criteria, staging, and classification system among treating physicians and research scientists working on this field. There is therefore an unmet need to obtain global consensus on the definition, classification, diagnosis, and staging of LSCD.

METHODS

A Limbal Stem Cell Working Group was first established by The Cornea Society in 2012. The Working Group was divided into subcommittees. Four face-to-face meetings, frequent email discussions, and teleconferences were conducted since then to obtain agreement on a strategic plan and methodology from all participants after a comprehensive literature search, and final agreement was reached on the definition, classification, diagnosis, and staging of LSCD. A writing group was formed to draft the current manuscript, which has been extensively revised to reflect the consensus of the Working Group.

RESULTS

A consensus was reached on the definition, classification, diagnosis, and staging of LSCD. The clinical presentation and diagnostic criteria of LSCD were clarified, and a staging system of LSCD based on clinical presentation was established.

CONCLUSIONS

This global consensus provides a comprehensive framework for the definition, classification, diagnosis, and staging of LSCD. The newly established criteria will aid in the correct diagnosis and formulation of an appropriate treatment for different stages of LSCD, which will facilitate a better understanding of the condition and help with clinical management, research, and clinical trials in this area.

Iatrogenic limbal stem cell deficiency following drainage surgery for glaucoma

OBJECTIVE

To describe conjunctival epithelial overgrowth of the cornea after surgery for glaucoma.

METHODS

This is a retrospective case series (setting: Moorfields Eye Hospital). Fourteen eyes of 13 patients with suspected limbal stem cell deficiency (LSCD) and corneal conjunctivalization after glaucoma drainage surgery. Conjunctivalization was defined as corneal epithelium that demonstrated late stain after topical application of fluorescein. Patient demographics, clinical features, potential risk factors, treatment, and final visual acuity were recorded. Main outcome measures were potential risk factors for conjunctivalization, complications, and response to treatment.

RESULTS

Eleven eyes had multiple procedures involving the limbus, and in 11 eyes mitomycin C (MMC) or 5 fluorouracil had been used as an adjunct to reduce fibrosis. Affected eyes typically had a segment of late stain with fluorescein based at the site of previous glaucoma surgery, but in one eye there was total loss of the corneal epithelial phenotype. All eyes previously had topical treatment for their glaucoma but only 2 had an ocular surface disease associated with LSCD. Most cases were asymptomatic, but in 3 eyes there was visual loss when the abnormal phenotype crossed the visual axis. In these 3 eyes there was recurrent epithelial breakdown, often at the interface between the 2 epithelial phenotypes. In one individual, these symptoms resolved after limbal epithelial transfer from the unaffected contralateral eye.

CONCLUSIONS

Glaucoma drainage surgery can damage the adjacent corneal limbal epithelial stem cell population. This can be associated with recurrent epithelial breakdown and reduced vision. If there is visual loss, limbal epithelial transplantation is a potential treatment option.

The diagnosis of limbal stem cell deficiency

Limbal stem cells (LSCs) maintain the normal homeostasis and wound healing of corneal epithelium. Limbal stem cell deficiency (LSCD) is a pathologic condition that results from the dysfunction and/or an insufficient quantity of LSCs. The diagnosis of LSCD has been made mainly based on medical history and clinical signs, which often are not specific to LSCD. Methods to stage the severity of LSCD have been lacking. With the application of newly developed ocular imaging modalities and molecular methods as diagnostic tools, standardized quantitative criteria for the staging of LSCD can be established. Because of these recent advancements, effective patient-specific therapy for different stages of LSCD may be feasible.

TFOS DEWS II iatrogenic report

Dry eye can be caused by a variety of iatrogenic interventions. The increasing number of patients looking for eye care or cosmetic procedures involving the eyes, together with a better understanding of the pathophysiological mechanisms of dry eye disease (DED), have led to the need for a specific report about iatrogenic dry eye within the TFOS DEWS II. Topical medications can cause DED due to their allergic, toxic and immuno-inflammatory effects on the ocular surface. Preservatives, such as benzalkonium chloride, may further aggravate DED. A variety of systemic drugs can also induce DED secondary to multiple mechanisms. Moreover, the use of contact lens induces or is associated with DED. However, one of the most emblematic situations is DED caused by surgical procedures such as corneal refractive surgery as in laser-assisted in situ keratomileusis (LASIK) and keratoplasty due to mechanisms intrinsic to the procedure (i.e. corneal nerve cutting) or even by the use of postoperative topical drugs. Cataract surgery, lid surgeries, botulinum toxin application and cosmetic procedures are also considered risk factors to iatrogenic DED, which can cause patient dissatisfaction, visual disturbance and poor surgical outcomes. This report also presents future directions to address iatrogenic DED, including the need for more in-depth epidemiological studies about the risk factors, development of less toxic medications and preservatives, as well as new techniques for less invasive eye surgeries. Novel research into detection of early dry eye prior to surgeries, efforts to establish appropriate therapeutics and a greater attempt to regulate and oversee medications, preservatives and procedures should be considered.

Pharmacotherapy and Immunotherapy of Conjunctival Tumors

Conjunctiva and cornea tumors represent a large spectrum of conditions ranging from benign lesions to aggressive and life-threatening malignancies. Topical pharmacotherapies and immunotherapies have recently acquired a relevant role in the management of conjunctival tumors and, in the past 2 decades, there has been a shift from surgery alone toward the use of these agents, both as a sole therapy or as adjunct to surgery (before or after surgery). The 3 main agents that have been used for topical medical treatment of conjunctival tumors are mitomycin-C, 5-fluorouracil, and interferon-α2b. Advantages of topical pharmacotherapies and immunotherapies include the ability to treat the entire ocular surface and prevention of surgical side effects and complications. The aim of this review is to summarize the current use of topical pharmacotherapy and immunotherapy in the management of conjunctival tumors.

[Adjuvant therapy and interdisciplinary follow-up care of conjunctival melanoma]

BACKGROUND

Despite microscopically controlled tumor excision, malignant melanomas of the conjunctiva have a propensity for local recurrence, lymphatic spread and distant metastases.

OBJECTIVES

This review outlines the options of adjuvant therapy as well as the structure of interdisciplinary follow-up care for patients with conjunctival melanoma.

METHODS

The study provides a PubMed literature review and own clinical results.

RESULTS

In conjunctival melanoma complete tumor excision using a minimal touch technique should always be combined with adjuvant therapy, such as cryotherapy, radiotherapy, topical chemotherapy and/or immunotherapy. For locally circumscribed lesions of the bulbar conjunctiva adjuvant brachytherapy can be supplemented and for non-bulbar, extensive, diffuse or multilocular tumor growth, complementary adjuvant topical mitomycin C therapy or proton radiotherapy can be used. Novel adjuvant approaches include topical interferon alpha-2b immunotherapy, topical vascular endothelial growth factor (VEGF) inhibitors or in cases of BRAF mutations personalized therapy using selective BRAF inhibitors or in combination with mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK), MAPK/ERK (MEK) inhibitors. All patients should be integrated into an interdisciplinary follow-up care program including quarter yearly checkups in the first 5 years and psycho-oncological healthcare.

CONCLUSION

Following microscopically controlled tumor excision, adjuvant treatment using cryotherapy, radiotherapy, topical chemotherapy and/or immunotherapy as well as interdisciplinary follow-up care are mandatory for the modern management of patients with conjunctival melanoma.

Fluorescence Confocal Microscopy for Ex Vivo Diagnosis of Conjunctival Tumors: A Pilot Study

PURPOSE

To evaluate the potential use of fluorescence confocal microscopy (FCM) for ex vivo diagnosis and excision margin assessment of conjunctival neoplasms.

DESIGN

Validity study.

METHODS

setting: Single institution.

PARTICIPANTS

Consecutive patients with clinically suspicious conjunctival lesions.

INTERVENTION

Conjunctival lesions were excised in toto using a standard "no-touch technique" by a single surgeon (A.I.). Collected specimens were examined with a commercially available laser scanning fluorescence confocal microscope after immersion in a 0.6 mM solution of acridine orange dye for 10-20 seconds. Specimens were subsequently processed with standard histologic analysis.

MAIN OUTCOME MEASURES

FCM diagnosis of the nature and extension of conjunctival lesions.

RESULTS

Sixteen consecutive patients were included in the study (11 male, 5 female; mean age 58.1 ± 26.1 years, range 10-90 years). The median time needed to process and analyze a sample with FCM was 15 minutes. Eleven of 16 lesions were identified by FCM as squamous (2 benign papillomas, 2 grade 2 conjunctival intraepithelial neoplasias, 7 in situ squamous carcinomas) and 5 as nonsquamous (1 pingueculum, 1 dermolipoma, 2 melanocytic nevi, 1 melanoma). In all cases FCM was able to detect horizontal and vertical extension of the lesion. All FCM findings were confirmed by corresponding subsequent histologic examination.

CONCLUSIONS

FCM provides a fast ex vivo preliminary diagnosis of suspicious conjunctival lesions with good histologic details and margin assessment, and may represent a novel tool for intraoperative and postsurgical management of conjunctival tumors. This is the first study to investigate ex vivo FCM application in ophthalmology.

Nine-Month Follow-up Results of Treatment for Nasolacrimal Duct Obstruction by Probing with Adjunctive Mitomycin C in Adults: A Prospective Randomized Placebo-Controlled Trial

The current study aimed to determine the efficacy of probing with adjunctive mitomycin C (MMC) as a treatment for nasolacrimal duct obstruction (NLDO) in adults and to study the association of probing success with demographic and obstruction characteristics. This was a prospective, randomized, double-blind, placebo-controlled trial including 140 patients (each with a unilateral NLDO) scheduled for nasolacrimal probing who were randomly assigned to receive MMC (0.2 mg/ml, 70 patients; group A) or placebo (normal saline, 70 patients; group B). Irrigation was carried out with 0.5 cc of MMC (0.2 mg/mL) in the duct with a nasal pack for 10 minutes in group A. Patients' postprobing epiphora was evaluated at 2 weeks and 1, 3, 6, and 9 months postoperatively. Probing was judged to be a success if there was no or mild watering for at least 9 months after the procedure. There were no significant differences between the two study groups in demographic characteristics or duration of the operation (p=0.062). The overall success rate of probing with MMC was 47/70 (67.1%), which was significantly higher than the success rate of the procedure with placebo (p=0.0027). When the sex of the patients was controlled for by logistic regression, a significant association between the failure rate of probing and increasing age was found in cases and controls (p=0.004 vs. p=0.006, respectively). No significant side effects of probing with MMC were noted after 9 months of follow-up. Administering MMC in a dosage of 0.2 mg/mL during nasolacrimal probing significantly increased the success rate of probing. The failure rate of probing increased with age. A low dose of MMC is cheap, safe, and easily accessible; thus, it is recommended during nasolacrimal probing, especially in patients who refuse dacryocystorhinostomy surgery.

Delayed manifestation of bilateral scleral thinning after I-BRITE(®) procedure and review of literature for cosmetic eye-whitening procedures

Purpose

To report a case of delayed-onset bilateral scleral thinning and calcium deposition following a cosmetic ocular-whitening procedure (I-BRITE^®).

Methods

A 33-year-old male patient with a history of right-sided ptosis repair and left-sided anterior uveitis had previously undergone bilateral I-BRITE treatment for chronic conjunctival hyperemia. Four years after the procedure, the patient was referred to our institution with bilateral scleral thinning and overlying calcific depositions. A literature review was performed through PubMed from 1980 through 2014 using the search terms ‘cosmetic’, ‘ocular’, ‘conjunctivectomy’, ‘regional conjunctivectomy’, ‘I-BRITE’, ‘eye-whitening’, ‘scleritis’, ‘necrotizing scleritis’, ‘anterior uveitis’, ‘mitomycin C’, ‘5-fluorouracil’, and ‘bevacizumab’, along with associated cross-referencing from relevant articles.

Results

Examination of the patient revealed bilateral necrotizing scleritis within the nasal region of both eyes. Calcified plaques were also present within the areas of scleromalacia, along with epithelial defects demonstrated with fluorescein staining. Although evidence of previous intraocular inflammation was apparent within the left eye, there were no active signs of inflammation evident within either eye on initial presentation. Complication rates reported in the literature include: scleral thinning (1.8%), calcific plaque formation (2.9%), fibrovascular proliferation (13%), diplopia (1.2%), elevation of intraocular pressure (4.2%), and recurrence of conjunctival hyperemia (2.1%).

Conclusion

Cosmetic ocular whitening procedures have an attendant high complication rate, and have been associated with several adverse postoperative complications, which have in turn generated several reservations regarding the veritable benefit of the procedure. Many postsurgical complications may demonstrate delayed apparition, varying from several months to several years after primary surgical intervention as in the case reported here.

Ocular surface disease in posttrabeculectomy/mitomycin C patients

Background

Our aim was to describe the demographics, risk factors, clinical signs, severity, and outcome of ocular surface disease (OSD) in 12 patients who had undergone trabeculectomy augmented with mitomycin C (MMC).

Methods

Twelve glaucoma patients were referred to the Dry Eye Clinic (Singapore National Eye Centre) for further management of clinically significant OSD.

Results

Of the 15 eyes from 12 patients, 14 were treated with MMC and one with 5-fluorouracil. Mean age was 69.3±10.6 years and two-thirds were male. The median interval before onset of dry eye symptoms after surgery was 13.5 months. Mean tear breakup time (TBUT) was 5.32 seconds and mean Schirmer score was 6.14 mm/5 min. Possible major risk factors for OSD in the cases include limbal stem cell deficiency occurring from exposure to antimetabolites, chronic use of antiglaucoma medications prior to surgery, and the preoperative status of the ocular surface prior to disease onset. Treatment of OSD resulted in improved best corrected visual acuity (BCVA) in 50% of the patients, with a median gain of two-line improvement in BCVA.

Conclusion

OSD is a clinical problem often overlooked in patients who undergo antimetabolite-augmented filtration surgery. Recognition of the condition and appropriate treatment can improve patient symptoms and reduce health-care burdens on the economy.

Conjunctival intraepithelial neoplasia. Interferon as a rescue therapy after failure of mitomycin C

CLINICAL CASE

The case of a 60 year-old male with a conjunctival lesion diagnosed as conjunctival intraepithelial neoplasia (CIN), who was treated with mitomycin-C for 3 weeks with minimal improvement. The therapy was change to interferon 2B. Six month later, and after a complete remission of the lesion, the treatment was suspended, with no signs of relapse.

DISCUSSION

The treatment of these lesions is currently made with chemotherapy and immunotherapy agents, such as mitomycin-C, 5-fluorouracil, and interferon alfa 2B. The latter, even although is the least used, gives excellent results with fewer secondary effects than mitomycin-C, resulting in an optimal therapy for the non-invasive treatment of CIN lesions.

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.

Rapamycin inhibits the production of myofibroblasts and reduces corneal scarring after photorefractive keratectomy

PURPOSE

Corneal stromal scarring partly involves the production of corneal myofibroblasts. The purpose of this study was to examine the effects of rapamycin (an inhibitor of the mammalian target of rapamycin [mTOR] pathway) on myofibroblast formation in vitro and in-vivo.

METHODS

Human corneal fibroblasts were grown in culture and transformed into myofibroblasts using TGF-β (2 ng/mL). The phosphorylation (activation) of the mTOR pathway was examined by immunoblotting. Cell proliferation with and without rapamycin was examined by thiazolyl blue tetrazolium bromide (MTT) assay and Ki67 staining. The expression of the myofibroblast differentiation marker smooth muscle actin (SMA) was examined by immunostaining and immunoblotting. The functional effects of rapamycin were measured using a gel contraction assay. For in vivo studies, 140 μm laser ablation was performed on rabbit corneas followed by subconjunctival rapamycin or vehicle. Corneal haze development was graded at 4 weeks, while the expression of myofibroblast markers was examined by immunostaining and immunoblotting.

RESULTS

The TGF-β activated the mTOR pathway with peak phosphorylation at 2 to 4 hours. Treatment of corneal fibroblasts with rapamycin reduced their proliferation by 46% compared to control. Rapamycin significantly inhibited TGF-β-induced expression of myofibroblast markers (17.2% SMA positive cells with rapamycin compared to 69.0% in control). Rapamycin also significantly inhibited TGF-β-induced collagen gel contraction. In the rabbit eyes treated with rapamycin, corneal haze development was significantly less compared to controls (0.75 ± 0.4 vs. 2.17 ± 0.7).

CONCLUSIONS

Rapamycin appears to inhibit proliferation and differentiation of corneal myofibroblasts and, thus, may provide an effective therapeutic measure for preventing corneal scarring.

Limbal epithelial cell therapy: past, present, and future

The cornea, the clear window at the front of the eye, transmits light to the retina to enable vision. The corneal surface is renewed by stem cells located at the peripheral limbal region. These cells can be destroyed by a number of factors, including chemical burns, infections, and autoimmune diseases, which result in limbal stem cell deficiency (LSCD), a condition that can lead to blindness. Established therapy for LSCD based on ex vivo expanded limbal epithelial cells is currently at a stage of refinement. Therapy for LSCD is also rapidly evolving to include alternative cell types and clinical approaches as treatment modalities. In the present perspectives chapter, strategies to treat LSCD are discussed and advances in this important field of regenerative medicine are highlighted.

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.

Treatment of conjunctival and corneal epithelial neoplasia with retinoic acid and topical interferon alfa-2b: long-term follow-up

OBJECTIVE

To evaluate the long-term recurrence rate of conjunctival and corneal intraepithelial neoplasia (CIN) treated with retinoic acid and topical interferon alfa-2b.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

A total of 89 eyes of 89 patients from 1 institution who were treated between September 2003 and February 2010 for CIN lesions used topical interferon alfa 1 million IU/ml drops 4 times daily and retinoic acid 0.01% once every second day.

METHODS

Diagnosis was made by biopsy and impression cytology. Patients' notes and clinical photographs were reviewed, and data were analyzed. All eyes were monitored for the possibility of recurrence with a minimum of 1 year of follow-up from the time of documented clinical resolution.

MAIN OUTCOME MEASURES

All eyes were monitored for the possibility of recurrence with a minimum of 1 year of follow-up from the time of documented clinical resolution.

RESULTS

Complete clinical resolution of the CIN lesions was achieved in 87 of the 89 eyes treated (97.75%). Two of the 89 eyes treated (2.25%) had only a partial response to treatment; of these 2 patients, 1 was taking cyclosporine for keratitis sicca. For the 87 eyes with complete response, resolution occurred after a mean of 1.69 months (range, 19 days to 6.5 months). Mean follow-up after clinical resolution (tumor-free period) was 51.5 months (range, 11-84 months). Four of the 87 patients with complete response developed a mild allergic papillary conjunctivitis that settled on halving the interferon dose to 0.5 million IU drops and reducing the frequency to 3 times daily. Side effects were limited to 1 case of epithelial microcysts and 1 case of marginal keratitis.

CONCLUSIONS

In this group of patients observed with CIN lesions, combination treatment of topical retinoic acid and interferon alfa-2b was effective in treating lesions with minimal self-limited side effects with faster and greater resolution and a longer tumor-free period compared with studies using interferon alfa-2b alone. We hypothesize that topical all-trans retinoic acid and interferon alfa-2b may act synergistically. We believe that combination treatment of interferon alfa-2b and retinoic acid may offer a superior alternative to interferon alfa-2b alone in treating CIN.

Concise review: limbal stem cell deficiency, dysfunction, and distress

The cornea is the clear tissue at the front of the eye that transmits light to the retina at the back of the eye. The cornea is covered by an epithelium and surrounded by a narrow band of tissue known as the limbus. The limbus has two important roles in maintaining a healthy corneal epithelium. First, stem cells for the corneal epithelium reside at the limbus and not in the cornea. Second, the limbus acts as a barrier separating the clear avascular corneal epithelium from the surrounding vascular conjunctival tissue. A failure of these limbal functions can result in the painful and blinding disease of limbal stem cell deficiency. In this disease, the corneal epithelium cannot be maintained by the stem cells, and the corneal surface becomes replaced by hazy conjunctival tissue. There are many causes of limbal stem cell deficiency, such as burns to the eye, inflammatory diseases, and hereditary diseases. Current understanding of the pathophysiology of the disease is discussed here. In particular, understanding whether the limbal stem cells are lost or become dysfunctional or indeed whether the limbal microenvironment is disturbed is important when developing appropriate management strategies for the disease.