Age-related ocular surface failure: A narrative review.

Ageing has been defined as a specific individual plasticity and remodeling capacity to the environment' insults and stimuli. The precise physiology of aging is not entirely understood. Several theories have been proposed and included programmed cell death, genetic mutations, the epigenetic clock, wear-and-tear and free radicals. Ocular surface represents a complex morpho-functional unit composed of different tissues that strictly interact to preserve homeostasis and function. Ageing severely disrupts this system by means of inflammaging and immunosenescence, leading to ocular surface failure in older population.

Tear film and ocular surface neuropeptides: Characteristics, synthesis, signaling and implications for ocular surface and systemic diseases.

Ocular surface neuropeptides are vital molecules primarily involved in maintaining ocular surface integrity and homeostasis. They also serve as communication channels between the nervous system and the immune system, maintaining the homeostasis of the ocular surface. Tear film and ocular surface neuropeptides have a role in disease often due to abnormalities in their synthesis (either high or low production), signaling through defective receptors, or both. This creates imbalances in otherwise normal physiological processes. They have been observed to be altered in many ocular surface and systemic diseases including dry eye disease, ocular allergy, keratoconus, LASIK-induced dry eye, pterygium, neurotrophic keratitis, corneal graft rejection, microbial keratitis, headaches and diabetes. This review examines the characteristics of neuropeptides, their synthesis and their signaling through G-protein coupled receptors. The review also explores the types of neuropeptides within the tears and ocular surface, and how they change in ocular and systemic diseases.

Corneal angiogenic privilege and its failure.

The cornea actively maintains its own avascular status to preserve its ultimate optical function. This corneal avascular state is also defined as "corneal angiogenic privilege", which results from a critical and sensitive balance between anti-angiogenic and pro-angiogenic mechanisms. In our review, we aim to explore the complex equilibrium among multiple mediators which prevents neovascularization in the resting cornea, as well as to unveil the evolutive process which leads to corneal angiogenesis in response to different injuries.

Inflammatory Stress Causes N-Glycan Processing Deficiency in Ocular Autoimmune Disease.

High levels of proinflammatory cytokines have been associated with a loss of tissue function in ocular autoimmune diseases, but the basis for this relationship remains poorly understood. Here we investigate a new role for tumor necrosis factor α in promoting N-glycan-processing deficiency at the surface of the eye through inhibition of N-acetylglucosaminyltransferase expression in the Golgi. Using mass spectrometry, complex-type biantennary oligosaccharides were identified as major N-glycan structures in differentiated human corneal epithelial cells. Remarkably, significant differences were detected between the efficacies of cytokines in regulating the expression of glycogenes involved in the biosynthesis of N-glycans. Tumor necrosis factor α but not IL-1ß had a profound effect in suppressing the expression of enzymes involved in the Golgi branching pathway, including N-acetylglucosaminyltransferases 1 and 2, which are required for the formation of biantennary structures. This decrease in gene expression was correlated with a reduction in enzymatic activity and impaired N-glycan branching. Moreover, patients with ocular mucous membrane pemphigoid were characterized by marginal N-acetylglucosaminyltransferase expression and decreased N-glycan branching in the conjunctiva. Together, these data indicate that proinflammatory cytokines differentially influence the expression of N-glycan-processing enzymes in the Golgi and set the stage for future studies to explore the pathophysiology of ocular autoimmune diseases.

Tears and ocular surface disorders: Usefulness of biomarkers.

INTRODUCTION: Corroborating data suggest that the analysis of tear fluid might represent an additional tool in the ophthalmological practice. AREAS COVERED: The purpose of this review was to sum up the tear protein profiles in healthy and diseased ocular surface and to highlight biomarker usefulness in the early diagnosis as well as at follow-up. This analysis encompasses a deep examination of the protein profile expression under physiological and pathological conditions. Tear protein profile analysis will allow in the near future discriminating between different grades of inflammation, from acute trauma toward immune-, endocrine-, and nervous-related disorders of the ocular surface. CONCLUDING REMARKS: The review provides an overview of old and recent findings about inflammatory mediators identified at the ocular surface, under physiological and pathological conditions. To date, the analysis of tear fluid represents a new additional approach for diagnosis and management of ocular surface diseases. Understanding the pathophysiological mechanism could also offer significant advantages to develop strategies addressed to better clarify some complex ocular surface disorders. To sum up, the possibility to provide selective biomarkers as a future target of specific diseases should be considered for supporting diagnosis and management of ocular surface diseases.

Phase II Randomized, Double-Masked, Vehicle-Controlled Trial of Recombinant Human Nerve Growth Factor for Neurotrophic Keratitis.

PURPOSE: To evaluate the safety and efficacy of topical recombinant human nerve growth factor (rhNGF) for treating moderate-to-severe neurotrophic keratitis (NK), a rare degenerative corneal disease resulting from impaired corneal innervation. DESIGN: Phase II multicenter, randomized, double-masked, vehicle-controlled trial. PARTICIPANTS: Patients with stage 2 (moderate) or stage 3 (severe) NK in 1 eye. METHODS: The REPARO phase II study assessed safety and efficacy in 156 patients randomized 1:1:1 to rhNGF 10 µg/ml, 20 µg/ml, or vehicle. Treatment was administered 6 drops per day for 8 weeks. Patients then entered a 48- or 56-week follow-up period. Safety was assessed in all patients who received study treatment, whereas efficacy was by intention to treat. MAIN OUTCOME MEASURES: Corneal healing (defined as <0.5-mm maximum diameter of fluorescein staining in the lesion area) was assessed by masked central readers at week 4 (primary efficacy end point) and week 8 (key secondary end point) of controlled treatment. Corneal healing was reassessed post hoc by masked central readers using a more conservative measure (0-mm staining in the lesion area and no other persistent staining). RESULTS: At week 4 (primary end point), 19.6% of vehicle-treated patients achieved corneal healing (<0.5-mm lesion staining) versus 54.9% receiving rhNGF 10 µg/ml (+35.3%; 97.06% confidence interval [CI], 15.88-54.71; P < 0.001) and 58.0% receiving rhNGF 20 µg/ml (+38.4%; 97.06% CI, 18.96-57.83; P < 0.001). At week 8 (key secondary end point), 43.1% of vehicle-treated patients achieved less than 0.5-mm lesion staining versus 74.5% receiving rhNGF 10 µg/ml (+31.4%; 97.06% CI, 11.25-51.49; P = 0.001) and 74.0% receiving rhNGF 20 µg/ml (+30.9%; 97.06% CI, 10.60-51.13; P = 0.002). Post hoc analysis of corneal healing by the more conservative measure (0-mm lesion staining and no other persistent staining) maintained statistically significant differences between rhNGF and vehicle at weeks 4 and 8. More than 96% of patients who healed after controlled rhNGF treatment remained recurrence free during follow-up. Treatment with rhNGF was well tolerated; adverse effects were mostly local, mild, and transient. CONCLUSIONS: Topical rhNGF is safe and more effective than vehicle in promoting healing of moderate-to-severe NK.

Toll-Like Receptors and Tissue Remodeling: The Pro/Cons Recent Findings.

The Toll-like Receptor (TLR) family ensures prompt response towards pathogens, protecting the host against infections, and guarantees a realistic balance between protective and detrimental activities. Multiple regulating mechanisms characterize TLR activity that is not limited to innate and adaptive antimicrobial immune responses, as observed in the inflammatory (either infective, allergic, or autoimmune) responses associated with tissue remodeling. Following the insult and the arise of inflammatory response, tissue remodeling takes place and might develop in fibrosis, depending on microenvironment as a result of imbalanced fibroblasts (FBs) and myofibroblasts (myoFBs) activation/survival. The process is driven by an epithelial-fibroblast-immune cell cross-talk. While the main FB function is the matrix metabolism for tissue homeostasis or repair, the myoFB differentiation represents a crucial step in attempting repair of injury. FBs/myoFBs provide more than structural support at site of injury, synthesizing and/or reacting to different cytokines, growth factors, neuromediators and soluble/lipid mediators. TLR-bearing FBs/myoFBs might contribute at the innate immune level, providing a second line of protection/defense as well as being a target/effector cell of tissue remodeling. TLRs might also interfere with acute inflammation as well as with established fibrosis, triggering structural/functional changes in agreement with the genetic background, the site of lesion, the entity of associated infection, the poor blood circulation or the pharmacological treatments, all together strictly influencing tissue repair/remodeling process. This review will focus on the recent findings on TLRs at launch and long-lasting tissue remodeling process, that strongly suggest TLRs as optional targets for future therapies.

Effects of Sex Hormones on Ocular Surface Epithelia: Lessons Learned From Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is the most common endocrine abnormality in women of reproductive age. Although its clinical consequences have been known for a long time to extend beyond the reproductive system, with type-2 diabetes and obesity being the most common, the involvement of the ocular surface in PCOS has been described only more recently. The ocular surface is a morphofunctional unit comprising eyelid margin, tear film, cornea, and conjunctiva. Increasing evidence indicates that these structures are under a sex hormone control and relevant diseases such as ocular allergy and dry eye are often caused by alterations in circulating or local steroid hormones levels. Novel treatments targeting sex hormone receptors on ocular surface epithelial cells are also being developed. In this review we aim to describe the current knowledge on the effects of sex hormones at the ocular surface, with a special focus on the effects of androgen imbalance in PCOS.

Cocaine snorting may induce ocular surface damage through corneal sensitivity impairment.

PURPOSE: Cocaine abuse may cause severe ischemic and necrotic tissue damage in several organs, including the eye. However, the cornea is an avascular tissue relying on sensitive nerves for its trophic support, and the pathogenesis of cocaine-induced corneal lesions is unclear. In this study, we aimed to investigate if corneal sensitivity, ocular surface, and tear function are damaged by habitual cocaine snorting. METHODS: Ocular examination, corneal sensitivity, and tear function testing were carried out in 48 cocaine addicts, and in 22 heroin addicts and 30 drug-free age/sex-matched individuals who served as controls. We also performed corneal confocal microscopy, conjunctival impression cytology, and tear sample collection to evaluate corneal and conjunctival morphology, and the presence of cocaine in tears. Statistical analysis was performed to compare groups and to correlate clinical findings with anamnestic data on cocaine use. RESULTS: We observed decreased corneal sensitivity in 26 cocaine addicts, and neurotrophic keratitis in six of them, with corneal damage, absence of symptoms, reduced tear production, and prolonged interblink-time. No significant changes in ocular surface parameters including corneal sensitivity were observed in heroin addicts. The major risk factors for developing cocaine-induced neurotrophic keratitis appeared to be duration and frequency of drug abuse. CONCLUSIONS: A complete ophthalmic evaluation including corneal sensitivity testing should be planned for an optimal management of cocaine addicts, even in the absence of ocular symptoms, to reduce the risk of corneal lesions and consequent vision impairment. Sensory nerve damage should also be evaluated in cocaine-induced lesions of other organs.

Molecular and biochemical expression of TLRs in human amniotic membrane: a comparative study of fresh and cryopreserved specimens.

BACKGROUND: To assess the expression of toll-like receptors (TLRs) in human amniotic membrane (AM) specimens and compare this expression with those of AMs undergoing the standard preservation procedure (handling) for ocular surgery. METHODS: Human fresh (n = 10; five spontaneous and five cesarean) or handled (n = 5) AMs were analyzed for TLR gene and protein expression. Two pieces were obtained from each specimen, and subjected to molecular or biochemical analysis. Relative real-time PCR and SDS-PAGE were carried out according to standard procedures. The REST-ANOVA coupled analysis was used to compare the molecular and biochemical data. RESULTS: The fresh membranes expressed all the TLRs (TLR1-10), with different gene expression as detected/evidenced by the Ct values, the intra-fresh group analysis showing that there was a variation of TLR expression whichvaried within the fresh membranes. The handled AMs retained the TLR expression after standard processing and preservation, but with a particular pattern which included a high TLR3/TLR4 and low TLR6 expression, when compared to the fresh membranes. The molecular data were confirmed by Western blot analysis. CONCLUSIONS: AM is routinely used in several ophthalmic surgical procedures, and notwithstanding its preservation procedure, AM is reported to favour wound healing and exert anti-angiogenic, anti-inflammatory, anti-scarring as well as anti-bacterial activities. The presence of TLRs in handled AM would imply that TLRs might be preserved in AMs used in ocular surgery. The findings herein described provide additional data concerning the presence of TLRs in cryopreserved AM, and suggest a possible contribution of AM in ocular surgery, via the innate immune response.

Management of porous orbital implants requiring explantation: a clinical and histopathological study.

PURPOSE: To perform a histopathological review of exposed porous orbital implants requiring explantation and to study the clinical outcome of replacement of the exposed implant with an autologous dermis-fat graft. METHODS: Case series. Analysis of the clinical charts of 25 patients (age 5 to 62 years) who were submitted to explantation of exposed hydroxyapatite orbital implants, followed by simultaneous replacement with a dermis-fat graft by 1 oculoplastic surgeon between 2000 and 2011. A histopathological and microbiological evaluation of implant sections was performed. This study adheres to the principles outlined in the Declaration of Helsinki. RESULTS: Microbiological examination showed the presence of Gram-positive cocci infection in 59% of the patients. Histopathological examination showed the presence of a chronic inflammatory infiltrate in 22 of the implants (88%) and significantly reduced fibrovascular colonization of the implant in all patients. CONCLUSIONS: The reduction of fibrovascular ingrowth resulted in poor integration of the implant in the eye socket. The exposure allowed bacterial colonization of the implant, causing a chronic inflammatory infiltrate. A dermis-fat graft at the same time of explantation can be considered a suitable surgical option in both adults and children: only minor complications may occur, and cosmetic results are satisfactory.

Ocular Surface Disease as Extraesophageal Gastroesophageal Reflux Disease Manifestation: A Specific Therapeutic Strategy.

PURPOSE: Gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) are common gastrointestinal disorders with extraesophageal manifestations (EGERD). Studies showed a correlation between GERD/LPR and ocular discomfort. Our aim was to report the prevalence of ocular involvement in patients with GERD/LPR, describe clinical and biomolecular manifestations, and provide a treatment strategy for this novel EGERD comorbidity. METHODS: Fifty-three patients with LPR and 25 healthy controls were enrolled in this masked randomized controlled study. Fifteen naive patients with LPR were treated with magnesium alginate eye drops and oral therapy (magnesium alginate and simethicone tablets) with a 1-month follow-up. Clinical ocular surface evaluation, Ocular Surface Disease Index questionnaire, tear sampling, and conjunctival imprints were performed. Tear pepsin levels were quantified by ELISA. Imprints were processed for human leukocyte antigen-DR isotype (HLA-DR) immunodetection and for HLA-DR, IL8, mucin 5AC (MUC5AC), nicotine adenine dinucleotide phosphate (NADPH), vasoactive intestinal peptide (VIP), and neuropeptide Y (NPY) transcript expression (PCR). RESULTS: Patients with LPR had significantly increased Ocular Surface Disease Index ( P < 0.05), reduced T-BUT ( P < 0.05), and higher meibomian gland dysfunction ( P < 0.001) compared with controls. After treatment, tear break-up time (T-BUT) and meibomian gland dysfunction scores improved to normal values. Pepsin concentration increased in patients with EGERD ( P = 0.01) and decreased with topical treatment ( P = 0.0025), significantly. HLA-DR, IL8, and NADPH transcripts were significantly increased in the untreated versus controls and comparable significant values were obtained after treatment ( P < 0.05). MUC5AC expression significantly increased with treatment ( P = 0.005). VIP transcripts were significantly higher in EGERD than in controls and decreased with the topical treatment ( P < 0.05). No significant changes were observed in NPY. CONCLUSIONS: We report an increase in prevalence of ocular discomfort in patients with GERD/LPR. The observations of VIP and NPY transcripts demonstrate the potential neurogenic nature of the inflammatory state. Restoration of the ocular surface parameters suggests the potential usefulness of topical alginate therapy.

Dupilumab-associated ocular surface disease or atopic keratoconjunctivitis not improved by dupilumab? Upadacitinib may clarify the dilemma: A case report.

Dupilumab-associated ocular surface disease is a common clinical sign appearing in patients with atopic dermatitis (AD) just few months after dupilumab treatment start, developing in about 25% of patients. Atopic keratoconjunctivitis (AKC) is a well-identified clinical entity, defined as a chronic inflammatory disease of eye that affects 25%-40% of patients with AD. Most clinical signs of ocular involvement in AD patients treated with dupilumab overlaps the AKC symptoms and signs. We supposed that Dupilumab-associated ocular surface disease and AKC represent the same disease but differently called by dermatologists and ophthalmologists. AKC-like disease may develop during dupilumab therapy as a consequence of alternative cytokines pathway activation (e.g. IL33) secondary to IL-4/13 pathway block. The novel upadacitinib drug may bypass ILs pathway through Janus Kinases selective inhibition, avoiding positive or negative ILs feedback at the ocular surface level. In this case report, molecular analysis on conjunctival samples showed a lower ocular surface inflammation (lower expression of HLADR) although higher levels of IL4 and IL13 in a patient with AD and AKC during upadacitinib therapy, compared to prior dupilumab treatment. Target therapies in patients suffering from AD may prevent ocular and dermatological comorbidities improving quality of life before quality of skin and vision.

Prophylactic Therapy for Long-Term Ocular Discomfort After Cataract Surgery.

PURPOSE: The cataract surgery dissatisfaction rate is 20% to 35% due to ocular surface discomfort. We investigate the ocular surface discomfort after surgical failure as a consequence of age-related parainflammation. We also aim to prevent it by immune-modulating prophylactic management. METHODS: Monocentric clinical trial realized in a teaching hospital. Prospective, randomized, open-label, unmasked clinical trial. One hundred patients diagnosed with cataracts underwent phacoemulsification surgery. Groups A (<65 years; n = 25) and B (>75 years; n = 25) received surgery only. Groups C and D (both >75 years and both n = 25) used cyclosporine A 0.1% cationic emulsion (CE) eye drops or CE lubricating eye drops (both twice daily), respectively, for 30 days before surgery. Patients were followed up 90 days after surgery. The primary outcome was postoperative ocular surface failure; secondary outcomes examined the influence of prophylactic cyclosporine A 0.1% CE therapy on ocular surface outcomes. RESULTS: Group B demonstrated greater severity regarding ocular surface signs and symptoms throughout the study period, versus all other groups. Signs/symptoms were typically lower in Group A. Group C achieved significant reductions in conjunctival Symptom Assessment in Dry Eye values ( P < 0.05), conjunctival hyperemia severity ( P < 0.01), and meibomian gland dysfunction ( P < 0.001) at Day 45, versus Group B, and tear break-up time was increased ( P < 0.001). Ocular surface inflammatory marker transcription (HLADR, intercellular adhesion molecule 1 [ICAM-1], and interleukin 6 [IL-6]) was significantly downregulated in Group C, versus Group B, at 90 days ( P < 0.05). CONCLUSIONS: Cataract surgery induced ocular surface system failure with a clinically significant persistent inflammatory status (InflammAging) in patients older than 75 years. Prophylactic cyclosporine A 0.1% CE eye drops were associated with improved ocular surface homeostasis and reductions in inflammatory markers.

The cellular mechanisms of dry eye: from pathogenesis to treatment.

Dry eye is a complex disease characterized by changes in the ocular surface epithelia related to reduced quality and/or quantity of tears, inflammatory reaction, and impairment of ocular surface sensitivity. It has recently been proposed that increased tear osmolarity represents a main trigger to the altered cellular mechanisms leading to epithelial damage in dry eye. However, dry eye pathogenesis is multifactorial, with cytotoxic inflammatory mediators, altered lacrimal gland secretion and nerve function, squamous metaplasia of the conjunctival epithelium and decrease of goblet cells density, all playing a role in a detrimental loop that perpetuates and worsens damage to the corneal and conjunctival epithelia. Current topical treatments for dry eye patients include the use of lubricants and anti-inflammatory drugs. However, lubricants only improve symptoms temporarily, and chronic use of topical steroids is associated to severe ocular side effects such as cataract and glaucoma. The deeper understanding of the cellular mechanisms that are altered in dry eye is opening novel perspectives for patients and physicians, who are seeking treatments capable not only of improving symptoms but also of restoring the homeostasis of the ocular surface. In this review, we will focus on novel anti-inflammatory agents and on nerve growth factor, a neurotrophin that is altered in dry eye and has been suggested as a main player in the neuroimmune cross-talk of the ocular surface as well as in the stimulation of corneal sensitivity, epithelial proliferation and differentiation, and stimulation of mucin production by goblet cells. J. Cell. Physiol. 228: 2253-2256, 2013. © 2013 Wiley Periodicals, Inc.

Hormones and dry eye syndrome: an update on what we do and don't know.

PURPOSE OF REVIEW: Dry eye syndrome (DES) prevalence is large and its relationship with hormonal diseases is becoming clearer, although more complex. This review provides insight to this association as well as clarifying what remains unanswered about how to interpret and treat findings common to both DES and hormonal diseases. RECENT FINDINGS: Several sex hormone-related diseases are associated with DES. Hormone replacement therapy to correct such conditions has conflicting outcomes based on epidemiologic studies and clinical trials. Thyroid-associated diseases are frequently involved in DES and must be investigated in cases where the cause of the ocular disease is undetermined. Diabetes mellitus is one of the major causes of DES, whereas correcting the metabolic imbalance minimizes its ocular symptomology. Gene therapy to treat DES-related hormonal diseases is a promising option based on animal studies. SUMMARY: Diagnosis and management of hormonal diseases can minimize the ocular surface damage and severity of DES. Clinical care of DES includes patient evaluation of hormonal status. Future research requires clarification of the underlying disease mechanisms and identifying novel strategies to reprogram the endocrine system rather than chronic medication usage.

A combined treatment for patients with dry eye and associated laryngopharyngeal reflux: a real-life approach.

AIM: To evaluate the efficacy and tolerability of administering a combined therapy in patients with dry eye syndrome (DES) and associated laryngopharyngeal reflux (LPR). METHODS: The study was retrospective, open, observational, and conducted in a real-life setting. Patients had pathological symptom assessment in dry eye (SANDE) and reflux symptom index (RSI) at baseline. Patients were re-assessed after 1mo and at the end of treatment. The treatment consisted of a three-month course based on the combined therapy: Gastroftal eye drops, one drop three times a day, and Gastroftal tablets, two tablets after lunch and two tablets after dinner. Tear break-up-time (TBUT) test, Schirmer test, RSI, and SANDE questionnaire were evaluated. RESULTS: The study included 253 patients. The mean age was 58±11.19y. TBUT test score and Schirmer's test significantly increased (both P<0.001) after 1mo and at the end of treatment. The RSI score and SANDE scores significantly decreased (both P<0.001) after 1mo and at the end of treatment. CONCLUSION: The current, retrospective, and open study shows that combined therapy using Gastroftal eye drops and tablets could represent a valuable option in managing patients with DES associated with LPR.