Dry eye and corneal langerhans cells in systemic lupus erythematosus

Examination of Subbasal Nerve Plexus and Central Corneal Stromal Microstructure in Subjects With Congenital Aniridia, Using in Vivo Confocal Laser Scanning Microscopy

PURPOSE

During life up to 70% of aniridia subjects develop aniridia-associated keratopathy (AAK). AAK is characterized by limbal stem cell insufficiency, impaired corneal epithelial cell differentiation and abnormal cell adhesion, which leads to centripetal spreading vascularization, conjunctivalization, and thickening of the cornea. Our aim was to examine the subbasal nerve plexus and central corneal stromal microstructure in subjects with congenital aniridia, using in vivo confocal laser scanning microscopy CLSM.

METHODS

31 eyes of 18 patients (55.6% males, mean age: 25.22 ± 16.35 years) with congenital aniridia and 46 eyes of 29 healthy subjects (41.4% males, mean age 30 ± 14.82 years) were examined using the Rostock Cornea Module of Heidelberg Retina Tomograph-III. At the subbasal nerve plexus, corneal nerve fiber density (CNFD), corneal nerve fiber length (CNFL), corneal total branch density (CTBD), and corneal nerve fiber width (CNFW) were analyzed using ACCMetrics software. Keratocyte density in the anterior, middle and posterior stroma was assessed manually.

RESULTS

The CNFD (2.02 ± 4.08 vs 13.99 ± 6.34/mm2), CNFL (5.78 ± 2.68 vs 10.56 ± 2.82 mm/mm2) and CTBD (15.08 ± 15.62 vs 27.44 ± 15.05/mm2) were significantly lower in congenital aniridia subjects than in controls (p < 0.001 for all). CNFW was significantly higher in aniridia subjects than in controls (0.03 ± 0.004 vs 0.02 ± 0.003 mm/mm2) (p = 0.003). Keratocyte density was significantly lower in all stromal layers of aniridia subjects than in controls (p < 0.001 for all). Stromal alterations included confluent keratocytes, keratocytes with long extensions and hyperreflective dots between keratocytes in aniridia.

CONCLUSIONS

Decrease in CNFD, CNFL, and CTBD, as well as increase in CNFW well refer to the congenital aniridia-associated neuropathy. The decreased keratocyte density and the stromal alterations may be related to an increased cell death in congenital aniridia, nevertheless, stromal changes in different stages of AAK have to be further analyzed in detail.

Unveiling Ocular Manifestations in Systemic Lupus Erythematosus

Systemic Lupus Erythematosus (SLE) is a complex autoimmune disorder characterized by immune dysregulation and multi-organ involvement. In this concise brief review, we highlight key insights into Ocular Systemic Lupus Erythematosus (SLE), an intricate autoimmune disorder with diverse organ involvement. Emphasizing the formation of autoantibodies and immune complex deposition, we delve into the inflammation and damage affecting ocular structures. Clinical presentations, ranging from mild dry eye syndrome to severe conditions like retinal vasculitis, necessitate a comprehensive diagnostic approach, including clinical exams, serological testing, and imaging studies. Differential diagnosis involves distinguishing SLE-related ocular manifestations from other autoimmune and non-inflammatory ocular conditions. The multidisciplinary management approach, involving rheumatologists, ophthalmologists, and immunologists, tailors treatment based on ocular involvement severity, encompassing corticosteroids, immunosuppressive agents, and biologics. Follow-up is crucial for monitoring disease progression and treatment response. Future perspectives revolve around advancing molecular understanding, refining diagnostic tools, and exploring targeted therapies. Novel research areas include genetic factors, microbiome composition, and biotechnology for tailored and effective SLE ocular treatments.

Dry eye disease: identification and therapeutic strategies for primary care clinicians and clinical specialists

Dry eye disease (DED) is a multifactorial disorder characterized by loss of tear film homeostasis with an estimated worldwide prevalence of 5% to 50%. In DED, dysfunction of the ocular structures that create and regulate the tear film components-including the lacrimal glands, meibomian glands, cornea, and conjunctiva-causes a qualitative and/or quantitative tear deficiency with resultant tear film instability and hyperosmolarity. This initiates a vicious cycle of ocular surface inflammation and damage that may ultimately impair the quality of life and vision of affected patients. Many factors can contribute to the development of DED, including ocular and systemic diseases, topical and systemic medications, and environmental conditions. Because DED is a chronic disorder, treatment is most often long term and may utilize both pharmacologic and nonpharmacologic interventions to address all etiologic components. The long-term management of DED can be challenging and most often should involve eye care specialist referral. However, primary care clinicians (PCCs) are often the first points of contact for patients with DED and importantly provide initial diagnosis and preliminary patient education about the disease process. Consideration of DED is also vital for the practice of various specialties due to the large number of comorbidities and medications that can contribute to DED pathogenesis and progression. Therefore, it is important that PCCs and clinical specialists be aware of the etiology of DED and its available therapeutic options. This manuscript provides an overview of DED pathophysiology and treatment and discusses specific considerations regarding DED management for PCCs and clinical specialists.Key messagesSuccessful management of dry eye disease often requires the use of various pharmacologic and/or nonpharmacologic therapies, as well as environmental and lifestyle modifications, to mitigate the underlying etiologies and restore tear film homeostasis.Primary care clinicians play an essential role in dry eye disease management by establishing a diagnosis, educating patients about the disorder, and providing referrals to eye care specialists for initiation of specialized treatment and long-term follow-up.Primary care clinicians and clinical specialists should consider prescribing medications with fewer ocular surface effects whenever possible in patients at risk for or with existing dry eye disease.

Confocal Microscopy Abnormalities Preceding Antibody Positivity and Manifestations of Sjogren's Syndrome

An asymptomatic 26-year-old woman underwent confocal microscopy as part of a control population for a research study. Images revealed reduced sub-basal corneal nerve density and multiple activated dendritic cells. Three years later, she presented with a self-limited cutaneous vasculitis in her lower extremities which prompted an evaluation for autoimmune diseases. Laboratory testing revealed positive antinuclear antibodies (1:320, thick granular pattern), and anti-SSA/SSB (SSA, 53.6 U/mL, moderately positive; SSB, 142.7 U/mL, strongly positive). Two weeks later, she presented with ocular pain and an ophthalmologic examination revealed ocular surface staining. An ocular ultrasound was consistent with posterior scleritis. Based on this picture, a diagnosis of Sjögren syndrome (SS) was made. SS is a chronic autoimmune disease that can present with symptoms that diminish the patient's quality of life. Confocal microscopy might be a valuable tool for the early diagnosis of disease.

Disrupted Neural Regeneration in Dry Eye Secondary to Ankylosing Spondylitis-With a Theoretical Link between Piezo2 Channelopathy and Gateway Reflex, WDR Neurons, and Flare-Ups

This study aimed at analyzing the corneal neural regeneration in ankylosing spondylitis patients using in vivo corneal confocal microscopy in correlation with Langerhans cell density, morphology, and dry eye parameters. Approximately 24 ankylosing spondylitis subjects and 35 age- and gender-matched control subjects were enrolled. Data analysis showed that all corneal nerve-fiber descriptives were lower in the ankylosing spondylitis group, implicating disrupted neural regeneration. Peripheral Langerhans cell density showed a negative correlation with nerve fiber descriptions. A negative correlation between tear film break-up time and corneal nerve fiber total branch density was detected. The potential role of somatosensory terminal Piezo2 channelopathy in the pathogenesis of dry eye disease and ankylosing spondylitis is highlighted in our study, exposing the neuroimmunological link between these diseases. We hypothesized earlier that spinal neuroimmune-induced sensitization due to this somatosensory terminal primary damage could lead to Langerhans cell activation in the cornea, in association with downregulated Piezo1 channels on these cells. This activation could lead to a Th17/Treg imbalance in dry eye secondary to ankylosing spondylitis. Hence, the corneal Piezo2 channelopathy-induced impaired Piezo2-Piezo1 crosstalk could explain the disrupted neural regeneration. Moreover, the translation of our findings highlights the link between Piezo2 channelopathy-induced gateway to pathophysiology and the gateway reflex, not to mention the potential role of spinal wide dynamic range neurons in the evolution of neuropathic pain and the flare-ups in ankylosing spondylitis and dry eye disease.

Examination of corneal microstructure in the quiescent phase of vernal keratoconjunctivitis using in vivo confocal microscopy

INTRODUCTION

This study investigated the morphological characteristics of corneal microstructure in the quiescent phase of vernal keratoconjunctivitis (VKC).

METHODS

Twenty patients with quiescent VKC and 25 healthy subjects were included. In vivo confocal microscopy (IVCM) of the central cornea was performed. Cellular density of each layer and the morphology of subbasal nerve plexus (SBNP) was analysed. Langerhans cell density (LCD), morphology (LCM), and field area (LCF) were also examined.

RESULTS

No differences were found either in cell densities nor in SBNP morphology (p > 0.05). LCD, LCM and LCF were significantly higher in the VKC group (p = 0.005, p < 0.001 and p < 0.001, respectively). The severity of papillary hypertrophy had a significant impact on LCD, LCM and LCF (β-coefficient: 19.541, p < 0.001; β-coefficient: 0.283, p < 0.001 and β-coefficient: 595.255, p < 0.001, respectively).

DISCUSSION

In quiescent VKC, LCD, LCM, and LCF were increased, and they were associated with the severity of papillary hypertrophy. Alterations of Langerhans cells indicate a subclinical inflammatory process without ocular symptoms.

Pathophysiology of Corneal Endothelial Cell Loss in Dry Eye Disease and Other Inflammatory Ocular Disorders

PURPOSE

Dry eye disease (DED) and other inflammatory ocular disorders have been reported to be associated with decreased corneal endothelial cell density (CECD), however the mechanism of underlying endothelial cell loss remains unknown.

METHODS

We conducted a comprehensive literature search of English-written publications on dry eye disease, corneal endothelial cell loss, Sjögren's syndrome, and Graft Vs Host Disease (GVHD), to review the effects of DED and other inflammatory ocular surface conditions on CECD.

RESULTS

A total of 78 studies were included in our study. Loss of corneal neurotrophic support, cytotoxic stress, and a heightened immune response, all of which may occur secondarily to a common causative agent such as inflammation, are major contributors to reduced CECD.

CONCLUSION

More studies are needed to determine how the interrelated pathways of altered corneal nerve function and upregulated expression of inflammatory activity influence corneal endothelial cell loss.

Corneal dendritic cells in diabetes mellitus: A narrative review

Diabetes mellitus is a global public health problem with both macrovascular and microvascular complications, such as diabetic corneal neuropathy (DCN). Using in-vivo confocal microscopy, corneal nerve changes in DCN patients can be examined. Additionally, changes in the morphology and quantity of corneal dendritic cells (DCs) in diabetic corneas have also been observed. DCs are bone marrow-derived antigen-presenting cells that serve both immunological and non-immunological roles in human corneas. However, the role and pathogenesis of corneal DC in diabetic corneas have not been well understood. In this article, we provide a comprehensive review of both animal and clinical studies that report changes in DCs, including the DC density, maturation stages, as well as relationships between the corneal DCs, corneal nerves, and corneal epithelium, in diabetic corneas. We have also discussed the associations between the changes in corneal DCs and various clinical or imaging parameters, including age, corneal nerve status, and blood metabolic parameters. Such information would provide valuable insight into the development of diagnostic, preventive, and therapeutic strategies for DM-associated ocular surface complications.

Corneal Langerhans cells in children with celiac disease

Celiac disease (CeD) is a common small bowel enteropathy characterized by an altered adaptive immune system and increased mucosal antigen presenting cells. This study aims to establish if quantification of corneal Langerhans cells (LCs) using corneal confocal microscopy (CCM) could act as a surrogate marker for antigen presenting cell status and hence disease activity in children with CeD. Twenty children with stable CeD and 20 age-matched controls underwent CCM and quantification of central corneal total, mature and immature LC density. There was no difference in age (11.78 ± 1.7 vs. 12.83 ± 1.91; P = 0.077) or height (1.38 ± 0.14 vs. 1.44 ± 0.13; P = 0.125). BMI (18.81 ± 3.90 vs. 22.26 ± 5.47; P = 0.031) and 25 OHD levels (43.50 ± 13.36 vs. 59.77 ± 22.45; P = 0.014) were significantly lower in children with CeD compared to controls. The total (33.33(16.67-59.37) vs. 51.56(30.21-85.42); P = 0.343), immature (33.33(16.67-52.08) vs. 44.79(29.17-82.29); P = 0.752) and mature (1.56(0-5) vs. 1.56(1.04-8.33); P = 0.752) LC density did not differ between the CeD and control groups. However, immature (r = 0.535, P = 0.015), mature (r = 0.464, P = 0.039), and total (r = 0.548, P = 0.012) LC density correlated with age. Immature (r = 0.602, P = 0.038) and total (r = 0.637, P = 0.026) LC density also correlated with tissue transglutaminase antibody (Anti-TtG) levels assessed in 12/20 subjects with CeD. There was no difference in corneal LC density between children with CeD and controls. However, the correlation between corneal LC density and anti-TtG levels suggests a relationship with disease activity in CeD and requires further study.

Density and distribution of dendritiform cells in the peripheral cornea of healthy subjects using in vivo confocal microscopy

PURPOSE

To establish dendritiform cell (DC) density and morphological parameters in the central and peripheral cornea in a large healthy cohort, using in vivo confocal microscopy (IVCM).

METHODS

A prospective, cross-sectional, observational study was conducted in 85 healthy volunteers (n = 85 eyes). IVCM images of corneal center and four peripheral zones were analyzed for DC density and morphology to compare means and assess correlations (p < 0.05 being statistically significant).

RESULTS

Central cornea had lower DC density (40.83 ± 5.14 cells/mm²; mean ± SEM) as compared to peripheral cornea (75.42 ± 2.67 cells/mm², p < 0.0001). Inferior and superior zones demonstrated higher DC density (105.01 ± 7.12 and 90.62 ± 4.62 cells/mm²) compared to the nasal and temporal zones (59.93 ± 3.42 and 51.77 ± 2.98 cells/mm², p < 0.0001). Similarly, lower DC size, field and number of dendrites were observed in the central as compared to the average peripheral cornea (p < 0.0001), with highest values in the inferior zone (p < 0.001 for all, except p < 0.05 for number of dendrites in superior zone). DC parameters did not correlate with age or gender. Inter-observer reliability was 0.987 for DC density and 0.771-0.922 for morphology.

CONCLUSION

In healthy individuals, the peripheral cornea demonstrates higher DC density and larger morphology compared to the center, with highest values in the inferior zone. We provide the largest normative cohort for sub-stratified DC density and morphology, which can be used in future clinical trials to compare differential changes in diseased states. Furthermore, as DC parameters in the peripheral zones are dissimilar, random sampling of peripheral cornea may be inaccurate.

Dry eye disease, a prominent manifestation of systemic autoimmune disorders

OBJECTIVES

Dry eye disease (DED) is arguably the most frequent ocular disease encountered in ophthalmic clinical practice. DED is frequently an underestimated condition causing a significant impact on visual function and quality of life. Many systemic autoimmune diseases (SAIDs) are related to moderate to severe DED. The main objective of this review is to enhance the awareness among ophthalmologists of the potential association of an underlying SAID in a high-risk patient with DED.

METHODS

An exhaustive literature search was performed in the National Library of Medicine's Pubmed, Scopus, Web of Science, and Google Scholar databases for all English language articles published until November 2021. The main keywords included "dry eye disease" associated with autoimmune, connective tissue, endocrine, gastrointestinal, hematopoietic, vascular, and pulmonary diseases. Case reports, series, letters to the editor, reviews, and original articles were included.

RESULTS

Although DED is frequently associated with SAIDs, its diagnosis is commonly delayed or missed, producing significant complications, including corneal ulceration, melting, scleritis, uveitis, and optic neuritis resulting in severe complications detrimental to visual function and quality of life. SAID should be suspected in a woman, 30 to 60 years old with a family history of autoimmunity, presenting with DED symptoms and extraocular manifestations including arthralgias, dry mouth, unexplained weight and hair loss, chronic fatigue, heat or cold intolerance, insomnia, and mood disorders.

CONCLUSIONS

Establishing the correct diagnosis and treatment of DED associated with SAIDs is crucial to avoid its significant burden and severe ocular complications.

Assessment of Tear Film Anomalies in Childhood Obesity

PURPOSE

To determine if childhood obesity has an effect on the ocular surface and tear film of children who are afflicted.

METHODS

Patients who had childhood obesity, 85 eyes, and patients who were healthy, 75 eyes, were enrolled in this prospective and comparative study. The tear film breakup time (TF-BUT), tear meniscus area and height (TMA and TMH) values, Schirmer test scores, and ocular surface disease index (OSDI) scores were obtained for all participants.

RESULTS

The TMH, TMA, TF-BUT, and Schirmer test results were statistically significantly lower in the obesity group (p < 0.001 for all). The children with obesity and insulin resistance had lower TMH, TMA, TF-BUT, and Schirmer test results when compared to the children without insulin resistance (p < 0.05 for all). The body mass index was found to be correlated with the TMH, TMA, TF-BUT, and Schirmer test results (p < 0.001 for all).

CONCLUSION

Children with obesity had lower TMA, TMH, TF-BUT, and Schirmer test results than healthy subjects. When insulin resistance was added to obesity, these values were even lower.

Subclinical Corneal Nerve Fiber Damage and Immune Cell Activation in Systemic Lupus Erythematosus: A Corneal Confocal Microscopy Study

Purpose

The purpose of this study was to evaluate the utility of corneal confocal microscopy (CCM) in identifying small nerve fiber damage and immune cell activation in patients with systemic lupus erythematosus (SLE).

Methods

This cross-sectional comparative study included 39 consecutive patients with SLE and 30 healthy control participants. Central corneal sensitivity was assessed using a Cochet-Bonnet contact corneal esthesiometer and a laser scanning CCM (Heidelberg, Germany) was used to quantify corneal nerve fiber density (CNFD), nerve branch density (CNBD), nerve fiber length (CNFL), and Langerhans cell (LC) density.

Results

Age was comparable among patients with SLE (33.7 ± 12.7) and controls (35.0 ± 13.7 years, P = 0.670) and the median duration of disease was 3.0 years (2.0–10.0 years). CNBD (P = 0.003) and CNFL (P = 0.019) were lower and mature LC density (P = 0.002) was higher, but corneal sensitivity (P = 0.178) and CNFD (P = 0.198) were comparable in patients with SLE compared with controls. The SELENA-SLEDAI score correlated with CNFD (ρ = −0.319, P = 0.048) and CNFL (ρ = −0.373, P = 0.019), and the total and immature LC densities correlated with CNBD (ρ = −0.319. P = 0.048, and ρ = −0.328, P = 0.041, respectively). Immature LC density was higher (P = 0.025), but corneal sensitivity and nerve fiber parameters were comparable between patients with (33%) and without neuropsychiatric symptoms and SLE.

Conclusions

Corneal confocal microscopy identifies distal corneal nerve fiber loss and increased immune cell density in patients with SLE and corneal nerve loss was associated with disease activity.

Translational Relevance

Corneal confocal microscopy may enable the detection of subclinical corneal nerve loss and immune cell activation in SLE.

Prevalence of dry eye in patients with systemic lupus erythematosus: a meta-analysis

OBJECTIVES

To investigate dry eye disease (DED) in patients affected by systemic lupus erythematosus (SLE).

METHODS

We conducted a systematic search of the literature on PubMed, EMBASE and the Cochrane Library databases from conception to 30 April 2020 for studies related to dry eye, secondary Sjögren's syndrome (sSS) and SLE. Original full-text articles with the number of patients diagnosed with SLE of over 15 were included. The risk of bias was evaluated with a validated critical appraisal tool which assessed study quality based on confounding factors, selection bias, bias related to measurement and bias related to data analysis. Data were extracted and pooled to evaluate the overall prevalence of DED with the random-effect model and sSS with the fixed effect model.

RESULTS

A total of 29 studies were included and 18 273 participants were involved. The pooled data showed that the overall prevalence of DED was 16% (95% CI 10% to 21%, p<0.001) in patients of SLE. Dry eye symptoms and abnormal Schirmer's test were found in 26% (95% CI 20% to 32%, p<0.001) and 24% (95% CI 14% to 34%, p<0.001) of patients with SLE, respectively. 12% (95% CI 9% to 15%, p<0.001) of patients also met the criteria of sSS. The OR of DED in patients with SLE was 4.26 (95% CI 3.47 to 5.05, p<0.001) compared with healthy controls. The meta-regression analysis showed that the sample size (p=0.004) and study location (p=0.022) could be the source of heterogeneity.

CONCLUSIONS

DED and sSS are both common in patients with SLE.

Anterior Segment Optical Coherence Tomography of Tear Film and Cornea in Systemic Lupus Erythematosus Patients

Purpose

To study tear film and corneal thickness measurements in systemic lupus erythematosus (SLE) patients compared to age-matched controls using anterior segment optical coherence tomography (AS-OCT).

Methods

This was a cross-sectional study. Study participants were divided into 3 groups: Group A: SLE patients with clinical dry eye, Group B: SLE patients without clinical dry eye and Group C: healthy controls. The lower tear meniscus parameters measured using AS-OCT were tear meniscus height (TMH), tear meniscus depth (TMD) and tear meniscus area (TMA). The central corneal and corneal epithelial thickness were automatically calculated.

Results

The study included 40 eyes in Group A, 60 in Group B, and 100 in Group C. Mean age was 26.9±6.6 years for Group A, 27.6±7.3 years for Group B and 35.7±9.2 years for Group C (p= 0.06). All subjects were females except for 1 male patient in Group A. Mean TMH, TMA and TMD in Group C were 487.7±185.6 µm, 0.068±0.040 mm², and 341.2±99.1 µm, respectively, which was significantly higher compared to Group A (225.5±27.9 µm, 0.018±0.004 mm² and 171.9±26.0 µm, respectively, all p < 0.001) and Group B (395.4±118.8 µm, p < 0.001; 0.05±0.04 mm², p=0.016 and 280.6±93.4 µm, p < 0.001, respectively). Group B eyes also had significantly higher parameters compared to Group A (all p < 0.001). Mean corneal and epithelial thickness in Group C were 501.6±37.5 µm and 53.3±4.5 µm, respectively, which was significantly higher compared to Group A (496.1±24.1 µm, p=0.044 and 49.5±3.5 µm, p < 0.001, respectively) and Group B (504.2±22.03 µm, p=0.046 and 47.5±5.6 µm, p < 0.001, respectively). Group B eyes also had a significantly higher corneal thickness (p=0.031) and epithelial thickness (p=0.011) compared to Group A.

Conclusion

We demonstrated significant reduction of tear meniscus dimensions, central corneal thickness and epithelial thickness in SLE patients compared to age-matched controls using AS-OCT.

Relationships between activated dendritic cells and dry eye symptoms and signs

PURPOSE

To examine whether "activated" dendritic cells (aDCs) could serve as a biomarker of systemic immune disorders in individuals with dry eye (DE) symptoms. Secondarily, to examine the impact of a topical anti-inflammatory agent on aDC number.

METHODS

Retrospective analysis was conducted to identify individuals with DE symptoms who had in-vivo confocal microscopy (IVCM) imaging between October 2018 and July 2020 at the Miami Veterans Hospital. aDCs were manually quantified based on morphology. Receiver operating curve (ROC) analysis examined relationships between aDC number and systemic immune disease status. Individuals were then grouped by aDC number (≥2 versus <2) and demographics and DE parameters were examined. Paired t-test was performed to evaluated aDC number pre-vs post-initiation of an anti-inflammatory agent.

RESULTS

128 individuals were included. Their mean age was 57.1 ± 15.0 years; 71.1% were male, 53.1% self-identified as White and 24.2% as Hispanic. The mean number of aDCs in the central cornea was 1.28 ± 2.16 cells/image. The presence of ≥2 aDCs had a sensitivity of 60% and specificity of 77% for the diagnosis of a systemic immune disorder. Individuals with ≥2 aDCs were more likely to self-identify as Black, have Secondary Sjögren's, and have higher nerve fiber area and fractal dimension. In 12 individuals, aDC number decreased from 2.69 ± 2.36 to 0.58 ± 0.73 cells/image after initiation of an anti-inflammatory agent, p = 0.01.

CONCLUSIONS

The presence of ≥2 aDCs in the central cornea suggests a systemic immune disorder in individuals with DE symptoms. Topical anti-inflammatory therapy can reduce the number of aDCs in the central cornea.

Advances in Screening, Early Diagnosis and Accurate Staging of Diabetic Neuropathy

The incidence of both type 1 and type 2 diabetes is increasing worldwide. Diabetic peripheral neuropathy (DPN) is among the most distressing and costly of all the chronic complications of diabetes and is a cause of significant disability and poor quality of life. This incurs a significant burden on health care costs and society, especially as these young people enter their peak working and earning capacity at the time when diabetes-related complications most often first occur. DPN is often asymptomatic during the early stages; however, once symptoms and overt deficits have developed, it cannot be reversed. Therefore, early diagnosis and timely intervention are essential to prevent the development and progression of diabetic neuropathy. The diagnosis of DPN, the determination of the global prevalence, and incidence rates of DPN remain challenging. The opinions vary about the effectiveness of the expansion of screenings to enable early diagnosis and treatment initiation before disease onset and progression. Although research has evolved over the years, DPN still represents an enormous burden for clinicians and health systems worldwide due to its difficult diagnosis, high costs related to treatment, and the multidisciplinary approach required for effective management. Therefore, there is an unmet need for reliable surrogate biomarkers to monitor the onset and progression of early neuropathic changes in DPN and facilitate drug discovery. In this review paper, the aim was to assess the currently available tests for DPN's sensitivity and performance.

[Antiangiogenic therapy in high-risk keratoplasty]

PURPOSE

To analyze the effectiveness and safety of VEGF inhibitor used to improve keratoconus transplant survival in patients with corneal neovascularization as stand-alone and in combination with laser coagulation of ingrowing vessels before keratoplasty.

MATERIAL AND METHODS

The study included 56 patients (56 eyes) with corneal opacifications of various etiology complicated by corneal neovascularization (CNV). The patients were divided into three groups. The 1st group included 27 patients with diffuse CNV who were undergoing an antiangiogenic therapy using anti-VEGF drug, the 2nd group - 14 patients with stem cell CNV who underwent laser coagulation of major corneal vessels combined with subconjunctival administration of drug before keratoplasty; the control group consisted of 15 patients with mixed type CNV who were undergoing conventional treatment without antiangiogenic therapy.

RESULTS

During the follow-up (24.5±4.84 months, 4 to 25 months), transplant rejection reaction was recorded in 7 (23%) patients of the 1^st group, 5 (35%) patients of the 2^nd group and 9 (60%) patients of the control group.

CONCLUSION

Subconjunctival administration of Aflibercept as a stand-alone measure and in combination with laser coagulation of ingrowing vessels may increase the chances of transparent transplant acceptance in high-risk keratoplasty.

Measurements of scleral thickness and corneal optic densitometry in patients with systemic lupus erythematosus

BACKGROUND

This study aimed to evaluate the scleral thickness and corneal parameters of patients with systemic lupus erythematosus (SLE).

METHODS

Forty-seven eyes of 47 SLE patients and 44 eyes of healthy controls were included in this cross-sectional study. Anterior segment optical coherence tomography (AS-OCT) was used to measure the corneal and scleral thickness. Scleral thickness (ST) was measured based upon the segmentation at 1000 to 5000 μm from the scleral spur. Pentacam HR was used to measure corneal parameters.

RESULTS

There was no statistically significant difference between SLE group and control group according to age and sex (P > .05). The ST measurements at all distances from scleral spur were found to be thicker in patients with SLE (P < .05). Central corneal thickness (CCT), cornea volume (CV), corneal densitometry (CD), and peripheral corneal thickness (PCT) measurements were similar between the groups (P > .05).

CONCLUSION

ST was thicker in SLE patients compared with healthy controls. AS-OCT seems helpful in selecting optimal sites for pharmaceutical or surgical intervention in SLE patients, since it shows thickness variations in anterior sclera.

In vivo confocal microscopy of the inflamed anterior segment: A review of clinical and research applications

In vivo confocal microscopy (IVCM) allows non-invasive imaging of the living human cornea, specifically enabling the detection of immune cells in the healthy and diseased ocular anterior segment. Studies using IVCM have provided insight into the effects of contact lens wear on corneal Langerhans cell density and morphology, and the effects of eye drops on conjunctiva-associated lymphoid tissue. IVCM has also been shown to be a useful adjunctive diagnostic tool in distinguishing infective and non-infective uveitis and in diagnosing atypical infective keratitis. In the research setting, this technology has enhanced our understanding of the role of inflammatory cells in corneal neuropathy and angiogenesis. In vivo-ex vivo correlation using animal models has helped overcome some of the difficulties in identifying cell type on IVCM images. As highlighted in this review, currently there are multiple established, and emerging, clinical and research applications for IVCM in the inflamed anterior segment.

Dry Eyes Status on Des Scale and Related Factors in Outpatients at Vietnam National Institute of Ophthalmology

BACKGROUND:

Dry eye (DE) can effect on quality of life by pain, inability to perform certain activities that require prolonged attention (driving, reading,…) and productivity at work and finally effect to Q0L associated with DE. OSDI is scale questionnaire is created team to measure the quality of life related to ocular surface disease.

AIM:

To describe the dry eye disease according to OSDI scale and related factors of this disease.

METHODS:

A cross-sectional descriptive study was carried out on outpatients (≥ 16-year-old) who were examined and diagnosed with dry eyes at Vietnam National Institute Of Ophthalmology from April to July 2018. Data was collected using the OSDI questionnaire.

RESULTS:

The average age of participants was 44.6 years; 80.9% of patients were female; 39.9% were identified having mild dry eye. The related factors have been identified that associated with severe dry eye, including age OR = 1.03 (95% CI: 1.01-1.05, p = 0.005), binocular good vision OR = 0.11 (95% CI: 0.05-0.23; p < 0.0001), medical history OR = 17.09 (95% CI: 2.24-130.25; p < 0.0001), chronic conjunctivitis OR = 0.36 (95% CI: 0.14-0.91; p = 0.027), refractive errors OR = 0.14 (95% CI: 0.04-0.48; p < 0.0001), Sjogren’s syndrome OR = 31.13 (95% CI: 7.08-136.76; p < 0.0001).

CONCLUSION:

Several related factors have been identified associated with severe dry eye, including: age, binocular good vision, medical history, chronic conjunctivitis, refractive errors, Sjogren’s syndrome.

C-Fiber Assays in the Cornea vs. Skin

C-fibers are unmyelinated nerve fibers that transmit high threshold mechanical, thermal, and chemical signals that are associated with pain sensations. This review examines current literature on measuring altered peripheral nerve morphology and discusses the most relevant aspects of corneal microscopy, especially whether corneal imaging presents significant method advantages over skin biopsy. Given its relative merits, corneal confocal microscopy would seem to be a more practical and patient-centric approach than utilizing skin biopsies.

Dry Eye Indexes Estimated by Keratograph 5M of Systemic Lupus Erythematosus Patients without Secondary Sjögren's Syndrome Correlate with Lupus Activity

Purpose

To investigate the incidence, severity, and influencing factors of dry eye in systemic lupus erythematosus (SLE) patients without secondary Sjögren's syndrome (sSS).

Methods

A total of 78 patients who were diagnosed with systemic lupus erythematosus and met inclusion criteria were selected as the study subjects in this cross-sectional study. Tear meniscus height (TMH) and noninvasive Keratograph tear breakup time (NIKBUT) including NIKBUT-first and NIKBUT-average of the subjects were measured using a noninvasive ocular analyzer, the Keratograph 5M (Oculus, Wetzlar, Germany). Symptoms related to dry eye were assessed using the Ocular Surface Disease Index (OSDI). The severity of SLE was evaluated by Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K). Results of the levels of 4 serum antibodies were collected from the patients' medical records. Correlations between SLEDAI and various ocular surface parameters were analyzed, and multiple-factor binary logistic regression analysis was conducted.

Results

In the study subjects, mean TMH was 0.22 mm, mean NIKBUT-first was 9.12 s, and mean OSDI was 13.14. The subjects (19 eyes) whose NIKBUT-average was < 10 s and OSDI was ≥ 13 accounted for 24.36% of all the included patients. SLEDAI showed a statistically significant correlation with TMH (r = −0.233, p=0.040), NIKBUT-first (r = −0.254, p=0.025), NIKBUT-average (r = −0.343, p=0.002), and OSDI (r = 0.256, p=0.024). According to multiple-factor binary logistic regression analysis, SLEDAI could be considered as a risk factor of the incidence of dry eye in SLE patients without sSS.

Conclusions

One-fourth of the SLE patients without sSS suffered from dry eye, and the severity of dry eye correlated with the activity of SLE.

Corneal epithelial dendritic cell density in the healthy human cornea: A meta-analysis of in-vivo confocal microscopy data

PURPOSE

Numerous studies have reported a wide range of corneal epithelial dendritic cells (CEDC) density using in-vivo confocal microscopy in healthy participants. It is necessary to establish normal CEDC values for healthy corneas to enable differentiation from pathological corneas. This meta-analysis aimed to establish CEDC density and distribution and examine their relationship with age and sex.

METHODS

A systematic review of the literature of studies using the Heidelberg Retinal Tomograph with Rostock Corneal Module and reporting CEDC density in healthy subjects up to December 2018 was conducted via Medline, Google Scholar, Scopus, PubMed, Embase and Cochrane library. A random effect modeling approach was used to obtain the results of meta-analysis and meta-regression was conducted to estimate the effect of age and sex.

RESULTS

38 studies reported central and 9 reported peripheral inferior CEDC density of 1203 participants (mean age 46.0 ± 12.2, range 18-81 years). CEDC density in the central and peripheral inferior cornea was 26.4 ± 13.6 cells/mm² (95% CI:22.5-26.8) and 74.9 ± 22.7 cells/mm² (95%CI:59.8-90.0), respectively. No effect of age was found on central CEDC density (p = 0.63); whereas peripheral CEDC density decreased with increasing age (p = 0.02). CEDC density was not influenced by sex at either location (p > 0.48).

CONCLUSION

This study established that the density at the peripheral inferior cornea is three-fold higher than at the central cornea. Peripheral but not central CEDC density decreased with increasing age. There are limited studies in youth (<18 years), precluding a more detailed analysis. Sex does not appear to be a significant factor in CEDC density.

Activation of Dendritic Cells in Dry Eye Mouse Model

Purpose

The immune system plays a major role in the pathogenesis of dry eye diseases (DED), and dendritic cells (DCs) are known to be important initiators of acquired immunity. Thus, the purpose of this study was to determine the contribution of DCs to the development of DED.

Methods

Mouse dry eye model was induced by subcutaneous injections of scopolamine and was euthanized at the baseline, and 2, 4, and 7 days postinjection. The activation of the DCs was determined by the mixed leukocyte reaction (MLR), and the number of activated CD86+ DCs in the lymph nodes was determined by flow cytometry. Upregulation of cytokines in the culture supernatant of MLR was determined by ELISA.

Results

Significantly increased superficial corneal punctate lesions and decreased number of goblet cells in the conjunctiva were observed in scopolamine-injected mice. The number of activated CD86+ DCs was significantly increased in the cervical lymph nodes but not in the inguinal lymph nodes of the dry eye mice. The stimulatory activity of the DCs derived from the cervical lymph nodes of dry eye mice was significantly higher than that of control mice, and upregulations of IL-17, IL-2, and IL-4 were observed in the culture supernatant of MLR. These results indicate that the DCs of the cervical lymph nodes were activated by the scopolamine injections.

Conclusions

Our results indicate that DCs in our dry eye model were sufficiently activated to stimulate the T cells that participate in the onset and progression of DED.

In Vivo Confocal Microscopy Evaluation of Ocular Surface with Graft-Versus-Host Disease-Related Dry Eye Disease

Dry eye disease (DED) is often elicited by graft-versus-host disease (GVHD), an extensive complication of hematopoietic stem cell transplantation (HSCT). To unravel the mechanism of this type of DED, in vivo confocal microscopy (IVCM) was used to investigate alterations in the state of the sub-basal nerves, dendritic cells (DCs) and globular immune cells (GICs) in the central cornea and limbal epithelia. In this study, we examined 12 HSCT recipients with GVHD-caused DED and 10 HSCT recipients without GVHD-associated DED and evaluated the clinical parameters in the 2 groups. Analysis of the central cornea and limbal epithelia using IVCM was conducted to investigate the density of the corneal sub-basal nerves, DCs and GICs as well as the tortuosity and branching of the sub-basal nerves. As suggested by our data, the clinical variables in the GVHD group were significantly different from those in the non-GVHD group. Additionally, GVHD-triggered DED conceivably increased the density of DCs and GICs in the central cornea and the density of DCs in limbal epithelia and altered the morphology of the sub-basal nerves. These phenomena are presumably correlated with the degree of inflammation. Thus, our findings may be translated into non-invasive diagnostic methods that indicate the severity of inflammation on the ocular surface in HSCT recipients.

Non-invasive objective and contemporary methods for measuring ocular surface inflammation in soft contact lens wearers - A review

Contact lens wear is one of the primary risk factors for the development of ocular surface inflammatory events. The purpose of this review is to examine and summarize existing knowledge on the mechanisms of contact lens related ocular surface inflammation and the evidence for the effectiveness of current objective methods to measure ocular surface inflammation. Contact lens wear is postulated to trigger an inflammatory response on the ocular surface due to mechanical, chemical, hypoxic stress, or by the introduction of microbes and their toxins. Apart from the traditional signs of inflammation, such as swelling, oedema, redness and heat, on the ocular surface, other methods to measure ocular surface inflammation in sub-clinical levels include tear inflammatory mediator concentrations, conjunctival cell morphology, and corneal epithelial dendritic cell density and morphology. Tear inflammatory mediator concentrations are up- or down-regulated during contact lens wear, with or without the presence of associated inflammatory events. There is higher conjunctival cell metaplasia observed with contact lens wear, but changes in goblet cell density are inconclusive. Dendritic cell density is seen to increase soon after initiating soft contact lens wear. The long term effects of contact lens wear on dendritic cell migration in the cornea and conjunctiva, including the lid wiper area, require further investigation. Currently patient factors, such as age, smoking, systemic diseases and genetic profile are being studied. A better understanding of these mechanisms may facilitate the development of new management options and strategies to minimize ocular surface inflammation related to contact lens wear.

Local ocular surface parameters in patients with systemic celiac disease

PurposeThis was a collaborative study from the Ophthalmology and Gastroenterology departments of a tertiary care hospital, designed to investigate the local ocular surface parameters in patients with celiac disease (CD).MethodsFifty-six eyes of 28 patients with CD and 58 eyes of 29 healthy adult subjects serving as controls were evaluated. The Schirmer test, tear-film break-up time, and conjunctival impression cytology were performed in addition to a complete ophthalmological examination. Impression cytology specimens of each group were graded and scored in the range 0-3.ResultsThe 28 patients with CD consisted of 24 females (86%) and 4 males (14%). The mean age was 34.4±11.3 years (22-55 years). Tear-film break-up time and Schirmer test results were significantly lower in the study group than in the controls (P<0.05). Also, there was a significant difference between the groups for impression cytology grading scores (P=0.001).ConclusionsThe CD group showed a marked preponderance of females with an F/M ratio of six females per male, as reported in the literature. Tear-film functions and conjunctival surface epithelial morphology were significantly altered in patients with CD.

Patients with multiple sclerosis demonstrate reduced subbasal corneal nerve fibre density

BACKGROUND

Many studies in multiple sclerosis (MS) have investigated the retina. Little, however, is known about the effect of MS on the cornea, which is innervated by the trigeminal nerve. It is the site of neural-immune interaction with local dendritic cells reacting in response to environmental stimuli.

OBJECTIVE

This study aims to investigate the effect of MS on corneal nerve fibres and dendritic cells in the subbasal nerve plexus using in vivo confocal microscopy (IVCM).

METHODS

We measured the corneal nerve fibre and dendritic cell density in 26 MS patients and matched healthy controls using a Heidelberg Retina Tomograph with cornea module. Disease severity was assessed with the Multiple Sclerosis Functional Composite, Expanded Disability Status Scale, visual acuity and retinal optical coherence tomography.

RESULTS

We observed significant reduction in total corneal nerve fibre density in MS patients compared to controls. Dendritic cell density was similar in both groups. Reduced total nerve fibre density was associated with worse clinical severity but not with previous clinical trigeminal symptoms, retinal neuro-axonal damage, visual acuity or disease duration.

CONCLUSION

Corneal nerve fibre density is a promising new imaging marker for the assessment of disease severity in MS and should be investigated further.

Severity of dry eye syndrome is related to anti-dsDNA autoantibody in systemic lupus erythematosus patients without secondary Sjogren syndrome: A cross-sectional analysis

There are as many as one-third of the systemic lupus erythematosus (SLE) patients who suffer from dry eye syndrome. To this date, dry eye syndrome in SLE patients is believed to be caused by secondary Sjogren syndrome (sSS). However, there is increasing evidence for possible independency of dry eye syndrome and sSS in patients suffering from autoimmune diseases. The purpose of this retrospective observational case series was to identify SLE patients without sSS who had dry eye syndrome, examine the correlation of different autoantibodies and dry eye severity, and determine the cause of dry eye in these patients.We included 49 consecutive SLE patients with dry eye who visited our dry eye clinic. In order to rule out sSS, these patients were all negative for anti-Sjogren's-syndrome-related antigen A and B (anti-SSA/SSB) and had no oral symptoms. Each patient's lupus activity was determined by serological tests including antidouble-stranded DNA antibody (anti-dsDNA), complement levels (C3, C4), erythrocyte sedimentation rate (ESR), and antinuclear antibody (ANA). Severity of dry eye syndrome was determined by corneal sensation (KSen), superficial punctuate keratopathy (SPK), Schirmer-I test (Schirmer), and tear film break-up time (TBUT). The autoantibodies and the dry eye parameters in each group were tested using the χ test or the Mann-Whitney U test for normally distributed or skewed data, respectively.The anti-dsDNA showed significant correlations with KSen (P < 0.001), SPK (P < 0.001), and Schirmer (P = 0.042) but not TBUT. The C3 showed significant correlations with KSen (P < 0.001), SPK (P < 0.001), and Schirmer (P = 0.014) but not TBUT. No correlations of dry eye parameters were observed between C4, ESR, and ANA.The major finding of this study was that the severity of dry eye syndrome in SLE patients without sSS was strongly correlated with anti-dsDNA and C3 but not with C4, ESR, and ANA.

Dry Eye Disease Patients with Xerostomia Report Higher Symptom Load and Have Poorer Meibum Expressibility

The purpose of the study was to investigate if xerostomia (dry mouth) is associated with symptoms and signs of dry eye disease (DED). At the Norwegian Dry Eye Clinic, patients with symptomatic DED with different etiologies were consecutively included in the study. The patients underwent a comprehensive ophthalmological work-up and completed self-questionnaires on symptoms of ocular dryness (Ocular Surface Disease Index [OSDI] and McMonnies Dry Eye Questionnaire) and the Sjögren’s syndrome (SS) questionnaire (SSQ). Three hundred and eighteen patients (52% women and 48% men) with DED were included. Patient demographics were: 0 to 19 years (1%), 20 to 39 (25%), 40 to 59 (34%), 60 to 79 (35%) and 80 to 99 (5%). Xerostomia, defined as “daily symptoms of dry mouth the last three months” (as presented in SSQ) was reported by 23% of the patients. Female sex was more common among patients with xerostomia (81%) than among non-xerostomia patients (44%; P<0.001). Patients with xerostomia (60 ± 15 years) were older than those without xerostomia (51 ± 17; P<0.001). The use of prescription drugs was more prevalent among xerostomia patients (65%) than among non-xerostomia patients (35%; P<0.021; adjusted for age and sex). Patients with xerostomia had a higher OSDI score (19.0 ± 10.0) than those without xerostomia (12.9 ± 8.0; P<0.001). Moreover, xerostomia patients had more pathological meibum expressibility (0.9 ± 0.7) than those without xerostomia (0.7 ± 0.8; P = 0.046). Comparisons of OSDI and ocular signs were performed after controlling for the effects of sex, age and the number of systemic prescription drugs used. In conclusion, xerostomia patients demonstrated a higher DED symptom load and had poorer meibum expressibility than non-xerostomia patients.

Observation of Corneal Langerhans Cells by In Vivo Confocal Microscopy in Thyroid-Associated Ophthalmopathy

PURPOSE

To examine the density and morphology of Langerhans cells (LCs) in the cornea of patients with thyroid-associated ophthalmopathy (TAO).

METHODS

Forty patients with TAO and 20 healthy volunteers were studied. All subjects underwent a thorough ophthalmic examination of both eyes. The ocular surface status was assessed by Ocular Surface Disease Index (OSDI) symptom questionnaires, tear break-up time (BUT), fluorescein staining and the Schirmer test. Laser scanning in vivo confocal microscopy was applied to evaluate the LC density and morphology in both central and peripheral cornea. The correlations between confocal microscopy data and clinical data were also analyzed.

RESULTS

The OSDI and fluorescein staining values were significantly higher, while BUT and Schirmer test scores were lower in both active and inactive TAO patients compared to the controls. Central LC densities of patients with active TAO (76.38 ± 67.77 cell/mm(2)) and inactive TAO (47.49 ± 38.58 cell/mm(2)) were both significantly higher than those of the controls (21.46 ± 21.74 cell/mm(2)). The number of LCs in the peripheral cornea was also significantly increased in the active TAO group (131.53 ± 74.18 cell/mm(2)) compared to the control group (70.21 ± 37.76 cell/mm(2)). Central LC morphology (LCM) values were significantly higher in both active (1.77 ± 0.63) and inactive (1.51 ± 0.63) TAO groups compared to the control group (1.01 ± 0.80), whereas peripheral LCM scores of the two TAO groups were increased without statistical significance. There were significant correlations between both central LC density and central LCM scores and clinical data, including clinical activity score, OSDI and Schirmer test scores, and between peripheral LC density and OSDI and Schirmer test scores. No significant correlations were found between peripheral LCM scores and clinical data.

CONCLUSIONS

The increase of corneal LCs in density and maturation in patients with TAO reflects an activated state of the local immune system, which indicates an inflammatory process in the cornea of TAO.

In Vivo Confocal Microscopy of the Human Cornea in the Assessment of Peripheral Neuropathy and Systemic Diseases

In vivo confocal microscopy (IVCM) of the living human cornea offers the ability to perform repeated imaging without tissue damage. Studies using corneal IVCM have led to significant contributions to scientific and clinical knowledge of the living cornea in health and pathological states. Recently the application of corneal IVCM beyond ophthalmology to wider clinical and research fields has been demonstrated. Abnormalities of the corneal subbasal nerve plexus have been associated with many forms of peripheral neuropathy and Langerhans cells correlate with systemic inflammatory states. There is a rapidly growing evidence base investigating the use of corneal IVCM in many systemic conditions and a well-established evidence base for IVCM imaging of the corneal subbasal plexus in diabetic peripheral neuropathy. This paper reviews the potential use of corneal IVCM in general clinical practice as a noninvasive method of assessing peripheral neuropathies, monitoring inflammatory states and clinical therapeutic response.