Tear Ferning Test and Pathological Effects on Ocular Surface before and after Topical Cyclosporine in Vernal Keratoconjunctivitis Patients

Amlodipine Ocular Delivery Restores Ferning Patterns and Reduces Intensity of Glycosylated Peak of Carrageenan-Induced Tear Fluid: An In-Silico Flexible Docking with IL-β1

BACKGROUND

The tear ferning test can be an easy clinical procedure for the evaluation and characterization of the ocular tear film.

OBJECTIVE

The objective of this study was to examine the restoration of tear ferning patterns and reduction of glycosylation peak after amlodipine application in carrageenan-induced conjunctivitis.

METHODS

At the rabbit's upper palpebral region, carrageenan was injected for cytokine-mediated conjunctivitis. Ferning pattern and glycosylation of the tear fluid were characterized using various instrumental analyses. The effect of amlodipine was also examined after ocular instillation and flexible docking studies.

RESULTS

Optical microscopy showed a disrupted ferning of the tear collected from the inflamed eye. FTIR of the induced tear fluid exhibited peaks within 1000-1200 cm-1, which might be due to the protein glycosylation absent in the normal tear spectrogram. The glycosylation peak reduced significantly in the tear sample collected from the amlodipine-treated group. Corresponding energy dispersive analysis showed the presence of sulphur, indicating protein leakage from the lacrimal gland in the induced group. The disappearance of sulphur from the treated group indicated its remedial effect. The flexible docking studies revealed a stronger binding mode of amlodipine with Interleukin-1β (IL-1β). The reduction in the intensity of the glycosylated peak and the restoration offering are probably due to suppression of IL-1β.

CONCLUSION

This study may be helpful in obtaining primary information for drug discovery to be effective against IL-1β and proving tear fluid as a novel diagnostic biomarker.

Vernal Keratoconjunctivitis: A Systematic Review

Vernal keratoconjunctivitis (VKC) is a chronic, bilateral corneal and conjunctival problem which typically presents in young individuals. VKC is characterized by itching, photophobia, white mucous discharge, lacrimation, foreign body sensation, and pain due to corneal involvement of shield ulcers. Vernal keratoconjunctivitis is categorized within ocular diseases. The diagnosis is clinical, as no sure biomarkers pathognomonic of the disease have yet been identified. The VKC therapy relies on different types of drugs, from antihistamines and topical steroids to cyclosporine or tacrolimus eye drops. In extremely rare cases, there is also the need for surgical treatment for the debridement of ulcers, as well as for advanced glaucoma and cataracts, caused by excessive prolonged use of steroid eye drops. We performed a systematic review of the literature, according to PRISMA guideline recommendations. We searched the PubMed database from January 2016 to June 2023. Search terms were Vernal, Vernal keratoconjunctivitis, and VKC. We initially identified 211 articles. After the screening process, 168 studies were eligible according to our criteria and were included in the review. In this study, we performed a systematic literature review to provide a comprehensive overview of currently available diagnostic methods, management of VKC, and its treatments.

Prevalence of allergic sensitization with vernal keratoconjunctivitis: A systematic review with meta-analyses

To determine the prevalence of allergic sensitization in patients with vernal keratoconjunctivitis (VKC) and to provide an overview of published studies on this topic. We systematically searched 11 literature databases on 24 May 2021, for studies with cross-sectional data on the prevalence of positive allergy tests in patients with VKC. Our main outcome of interest was the prevalence of allergic sensitization and the allergens involved. Prevalence meta-analyses were made to provide summary estimates. We identified 33 eligible studies for qualitative review with 2122 patients with VKC. Studies were predominantly based on patients seen in ophthalmology clinics. Overall, studies reported that the most prevalent positive allergen tests were the inhaled allergens house dust mites and pollen. Twenty-nine studies were eligible for the quantitative analysis. Here, we calculated the prevalence of allergen-positive patients to 57.7% (95% confidence interval: 52.5%-62.8%). Subgroup analyses of pooled estimates on sensitization based on specific testing methods found prevalence estimates of 51.4% for conjunctival provocation test, 68.7% for total tear IgE, 58.9% for specific tear IgE, and 58.2% for skin prick test. The prevalence of allergic sensitization in patients with VKC is 57.7%, and mostly towards inhaled allergens. The most frequent positive allergens are house dust mites and pollen. Identifying possible clinically relevant allergens provide information that may aid in managing VKC, such as environmental allergy-avoidance or allergy-specific treatment.

Advances in Dry Eye Disease Examination Techniques

Dry eye-related ocular surface examination is very important in the diagnosis and treatment of dry eye disease. With the recent advances in science and technology, dry eye examination techniques have progressed rapidly, which has greatly improved dry eye diagnoses and treatment. However, clinically, confusion remains about which examination to choose, how to ensure the repeatability of the examination, and how to accurately interpret the examination results. In this review, we systematically evaluate previous examinations of dry eye, analyze the latest views and research hotspots, and provide a reference for the diagnosis and management of dry eye.

Diagnostic tests based on pattern formation in drying body fluids - A mapping review

There are numerous diagnostic tests based on pattern formation in desiccating body fluids, where the pattern or some of its characteristics constitute the diagnostic test outcome. However, partially due to the development in different time periods, and partially due to publications in languages different from English, most of these diagnostic tests exist as separate approaches and have never been grouped, systematized, nor compared with each other. In the present mapping review, we performed a wide literature search with the aim to collect all diagnostic tests based on pattern formation in desiccating body fluids. Furthermore, we grouped the identified diagnostic tests according to their experimental protocols, type of body fluids investigated, and target conditions, and propose so for the first time a classification of different diagnostic tests based on pattern formation in desiccating body fluids. The literature search revealed 1603 publications, out of which 141 were included into the review. Following three main classification criteria (way of deposition of the fluid for desiccation, addition of reagents, and spatial restrictions during evaporation), we identified six different methods; following a further classification concerning the analyzed body fluid we identified 30 different diagnostic tests based on pattern formation in evaporating body fluids. Amongst these tests are well-known procedures such as ferning tests (tear ferning for the assessment of tear film quality, saliva and cervical mucus ferning for the detection of the fertile period, and amniotic fluid ferning for the diagnosis of fetal membrane rupture), whereas other tests are less well-established. In the latter group, the most frequently investigated body fluids were serum, saliva, and blood; the most frequently addressed target conditions were cancer, inflammation, and benign tumors. We recommend conducting further systematic reviews and meta-analyses concerning groups of methods addressing the same target condition.

Efficacy of medical treatments for vernal keratoconjunctivitis: A systematic review and meta-analysis

BACKGROUND

Vernal keratoconjunctivitis (VKC) is a severe type of allergic conjunctivitis for which treatment strategies are still under debate.

OBJECTIVES

This study sought to conduct a systematic review and meta-analysis to evaluate the efficacy of medical treatments for VKC.

METHODS

The PubMed, Cochrane Library, Embase, and ScienceDirect databases were searched to assess the efficacy of treatments for VKC. Random-effect meta-analyses on changes in clinical scores of symptoms and signs between baseline and after treatment, stratified on treatment classes, were computed. Meta-regressions were searched for potential influencing parameters.

RESULTS

Included were 45 studies (27 randomized controlled trials and 18 prospective cohort studies), 1749 patients (78% were men; mean age, 11.2 years), and 12 different treatment classes. Mast cell stabilizers (MCSs; usually considered as first-line therapy), cyclosporine, and tacrolimus were the most studied drugs (in three-quarters of studies). Overall, all clinical scores improved. Total symptom and sign score decreased for MCSs (effect size, -3.19; 95% CI, -4.26 to -2.13), cyclosporine (effect size, -2.06; 95% CI, -2.72 to -1.40), and tacrolimus (effect size, -2.39; 95% CI, -3.36 to -1.43). No significant differences were shown depending on treatment classes, concentration, age, sex, baseline activity scores, and atopy. Sensitivity analyses demonstrated similar results.

CONCLUSIONS

This study confirms the efficacy of MCSs in the treatment of VKC. Efficacy of cyclosporine and tacrolimus did not differ, suggesting that tacrolimus is a good alternative to cyclosporine for severe cases of VKC. Further studies are needed to compare other drugs and their precise place in treatment strategy.

Establishment of a Tear Ferning Test Protocol in the Mouse Model

Purpose

Analysis of ferning formation after tear drop desiccation on a glass slide has been applied as a simple method to examine tear normality and is referred to as the tear ferning (TF) test. Despite use of the TF test in clinical settings and in some animals, thus far no TF test protocol has been developed for the mouse model. This study aimed to establish a mouse TF test protocol that can be used for dry eye research using the mouse as the study model.

Methods

Tear samples were collected from 24 healthy mice after repeated flushes with 2, 5, 10, or 20 µL wash solutions, either 0.9% NaCl saline or sterile water, on the ocular surface. After sample collection, TF tests were performed at variable drop volumes (2–20 µL), at a relative humidity of either 46% ± 2% or 53% ± 2%, and with temperature fixed at 24°C ± 2°C for comparison. Moreover, the influence of osmolarity (between 280 and 360 mOsm/L) and pH values (6.5–8.0) and the effect of centrifugation (4000 rpm, 10 minutes) on ferning formation were examined. Reproducibility and ferning storage stability were also determined.

Results

An optimized protocol was established with relative humidity at 46% ± 2% and drop aliquot at 2 µL, using 0.9% NaCl saline as the wash solution. Using sterilized water as the wash solution did not result in any crystalloid formation. Centrifugation did not aid ferning formation in any of the samples. Higher osmolarity increased ferning formation from grades between 0 to 1 to grades between 2 to 3, but pH values that varied between 6.5 and 8.0 did not affect ferning formation. The established mouse TF test protocol also displayed reproducibility and storage stability.

Conclusions

A TF test protocol for the mouse model was established that could be used for comparative analyses under various ocular surface disease conditions.

Translational Relevance

This mouse TF test protocol will facilitate the application of basic research into the mouse model to clinical care.

Eye drop emulsion containing 0.1% cyclosporin (1 mg/mL) for the treatment of severe vernal keratoconjunctivitis: an evidence-based review and place in therapy

Vernal keratoconjunctivitis (VKC) is a rare, recurrent and multifactorial ocular disease, which typically flares up during spring and affects especially male children and adolescents. This condition does not usually respond to common treatments with antihistamines or mast cells stabilizers, whereas corticosteroids have effective results. Corticosteroids need to be carefully administered, to avoid adverse effects, mainly the secondary development of glaucoma, cataracts, or infections. Immunosuppressive agents, such as cyclosporin (CyA) or tacrolimus are, therefore, frequently employed in VKC patients. Only the 0.1% CyA (1 mg/mL) concentration has an approved and specific clinical indication for the treatment of VKC and this drug was given the denomination of orphan drug by the European Commission (EU/3/06/360) in 2006. So far, few studies have been conducted to evaluate the efficacy and the side effects of topical 0.1% CyA. Different topical CyA concentrations, ranging from 0.05% to 2%, and various types of formulation are available at the moment. In the future, 0.1% CyA will presumably take an important part in the management of VKC. The present review focuses on eye drops containing 0.1% CyA; however, more studies will be needed to define its long-term efficacy in the natural course of this severe ocular disease.

Effects of short-term oral vitamin A supplementation on the ocular tear film in patients with dry eye

Objective

To investigate the effects of short-term oral vitamin A supplementation on the ocular tear film in patients with dry eye.

Methods

In total, 30 male patients with dry eye (age range, 18–38 years; mean age, 25.2±2.8 years) who did not wear contact lenses or exhibit any ocular (other than dry eye) or systemic diseases were included, along with 30 age-matched men (control group; mean age, 24.5±2.3 years) with healthy eyes. Subject exclusion was based on the findings of the McMonnies questionnaire (cutoff score for dry eye: 14.5) and slit-lamp biomicroscopy. All subjects received an oral vitamin A supplement at a daily dose of 1,500 mg for 3 consecutive days. The phenol red thread (PRT) test was performed along with assessments of tear ferning (TF), tear osmolarity, and the tear break-up time (TBUT) before and 24 hours after the third dose of the vitamin A supplement. A 10-minute interval was observed between different tests.

Results

In the dry eye group, the TF grade (Wilcoxon test, P=0.01) exhibited a significant decrease, while the tear osmolarity value (t-test, P=0.01) exhibited a significant increase after vitamin A supplementation. The PRT test findings (P=0.17) and TBUT (P=0.49) showed no significant differences before and after vitamin A supplementation. In the control group, vitamin A supplementation showed no significant effects on TF (P=0.74), tear osmolarity (P=0.55), the TBUT (P=0.19), and the PRT test scores (P=0.48).

Conclusion

Our findings suggest that short-term oral vitamin A supplementation improves the quality, but not quantity, of tears in patients with dry eye. Future studies should involve larger patient samples and longer periods of vitamin A supplementation.