New approaches for diagnosis of dry eye disease

Dry Eye Disease: An Update on Changing Perspectives on Causes, Diagnosis, and Management

Dry eye disease is a common clinical problem encountered by ophthalmologists worldwide. Interest in this entity has increased in recent years due to the consequences it has on the ocular surface after any surface procedure. With changing times, several new factors have come to light that can influence this disease. The effect of the COVID-19 pandemic has also been greatly felt, with a range of causes, starting from increased screen work to inflammatory processes, exacerbating the condition in many. With changes in the concepts of the etiopathogenesis of the disease, a paradigm shift has taken place in the approaches to treatment. More researchers are in favor of a new tear film-oriented approach that tries to localize the disease to a single component in the tear film. Innovation of newer techniques for the treatment of meibomian gland disease has also made its foray into clinical ophthalmology. Newer drug formulations and molecules are underway to better treat the inflammatory component of the disease. Many other receptors and targets for the treatment of dry eyes are being researched. This review hopes to provide a succinct, narrative summary of the relevant research on dry eye disease to date to increase awareness about the nature and future course of this disease and its management.

The Human Ocular Surface Microbiome and Its Associations with the Tear Proteome in Dry Eye Disease

Although dry eye disease (DED) is one of the most common ocular surface diseases worldwide, its pathogenesis is incompletely understood, and treatment options are limited. There is growing evidence that complex interactions between the ocular surface microbiome (OSM) and tear fluid constituents, potentially leading to inflammatory processes, are associated with ocular surface diseases such as DED. In this study, we aimed to find unique compositional and functional features of the OSM associated with human and microbial tear proteins in patients with DED. Applying whole-metagenome shotgun sequencing of forty lid and conjunctival swabs, we identified 229 taxa, with Actinobacteria and Proteobacteria being the most abundant phyla and Propionibacterium acnes the dominating species in the cohort. When DED patients were compared to controls, the species Corynebacterium tuberculostearicum was more abundant in conjunctival samples, whereas the family Propionibacteriaceae was more abundant in lid samples. Functional analysis showed that genes of L-lysine biosynthesis, tetrapyrrole biosynthesis, 5-aminoimidazole ribonucleotide biosynthesis, and the super pathway of L-threonine biosynthesis were enriched in conjunctival samples of controls. The relative abundances of Acinetobacter johnsonii correlated with seven human tear proteins, including mucin-16. The three most abundant microbial tear proteins were the chaperone protein DnaK, the arsenical resistance protein ArsH, and helicase. Compositional and functional features of the OSM and the tear proteome are altered in patients with DED. Ultimately, this may help to design novel interventional therapeutics to target DED.

Perceived Eye-Related Symptoms and Influencing Factors in Hospital Nurses

Nurses are at risk of eye discomfort due to the increasing use of visual display terminals and wearing masks, which may worsen eye-related symptoms. This study was conducted in South Korea to identify the factors influencing eye-related symptoms among hospital nurses on/off duty. The study included 154 nurses who completed a self-reported questionnaire that assessed demographic characteristics, perceived health status, dry-eye symptoms, occupational stress, and eye-related symptoms. The results showed that nurses complained of more eye-related symptoms on duty than off duty, with female sex and dry-eye symptoms being the factors influencing eye-related symptoms on duty. On the other hand, computer use time (≥4 h) and dry-eye symptoms were the factors influencing eye-related symptoms off duty. The study suggests that assessing dry-eye symptoms can facilitate early interventions to relieve eye-related symptoms in hospital nurses, and they should pay attention to eye health during working hours as well as off hours.

Accuracy of a New Noninvasive Automatic Ocular Surface Analyzer for the Diagnosis of Dry Eye Disease-Two-Gate Design Using Healthy Controls

PURPOSE

The purpose of this study was to assess the diagnostic performance of measurements from a new noninvasive, automated ocular surface analyzer (IDRA) in the diagnosis of dry eye disease (DED).

METHODS

We prospectively identified patients with and without DED using best practice methods. Subsequently, all participants underwent IDRA analysis, consisting of 5 components: noninvasive tear film break-up time, tear meniscus height, lipid layer interferometry, eye blink quality, and infrared meibography. The manufacturer provides cutoff values for a pathologic result for each of these components. Using a stepwise augmentation multivariate logistic regression model, we identified the components with the strongest association for the presence of DED. For the 3 components with the strongest association (interferometry, tear meniscus, and infrared meibography), we calculated the probability of DED.

RESULTS

We enrolled 40 patients (80 eyes) with DED (mean age 60.5 years; women 78.3%) and 35 healthy subjects (70 eyes, mean age 31.1 years; women 21.7%). The IDRA had an area under the curve of 0.868 (95% confidence interval: 0.809-0.927) to detect DED. A normal (≥80) interferometry combined with a normal (>0.22) tear meniscus and a normal (≤40) infrared meibography was associated with an estimated probability of 18% for the presence of DED, whereas the estimated probability of DED was as high as 96% when all 3 findings were pathologic.

CONCLUSIONS

The results of IDRA showed a positive concordance with routine clinical diagnostic tests. The new analyzer is an easy-to-access diagnostic tool to rule out the presence of DED in the extramural setting and to guide a timely DED treatment.

Ocular Surface Disease in Glaucoma Patients

PURPOSE

To review the most recent studies in the literature regarding the ocular surface in glaucoma patients and treatment options aimed to reduce ocular surface disease in this population.

METHODS

We performed a literature search in the electronic databases of PubMed CENT RAL, Google Scholar, EMBASE the Register of Controlled Trials, and Ovid MEDLINE using the following terms: "ocular surface", "dry eye", "glaucoma", "selective laser trabeculoplasty", "glaucoma surgery", "preservatives", "preservative free", "ocular surface disease index", "tear break up time", "MMP-9" and "conjunctival hyperemia".

RESULTS

Over the last several years, several studies have demonstrated the changes to the ocular surface in the setting of glaucoma, the best tests for markers of dry eye, and how management can be altered to help address ocular surface disease routinely or in preparation for glaucoma surgery.

CONCLUSION

Ocular surface disease in the glaucoma patient population is widely recognized. It should be addressed to maximize patient compliance and quality of life.

[Risk factors, clinical features and indications for treatment of dry eye disease at a young age]

In recent decades, there has been an increase in the prevalence of dry eye disease (DED) not only in older people, but also in young people, which is potentially associated with the use of digital devices. Early detection of signs of DED and the appointment of preventive tear replacement therapy can help stabilize the tear film and slow down the progression of the disease.

PURPOSE

To study risk factors, prevalence and clinical manifestations of DED in young people, to determine indications and evaluate the effectiveness of treatment with artificial tears.

MATERIAL AND METHODS

The study included 91 patients aged 21 to 39 years (mean age 22.4±0.35 years), 63 (69.2%) women and 28 men (30.8%). All patients had tear film breakup time (TBUT) measured and underwent Schirmer I test, LIPCOF, ocular surface staining with vital dyes, lacrimal OCT-meniscometry and filled a questionnaire. To determine the effectiveness of the tear replacement therapy, 45 people prescribed sodium hyaluronate solution were randomly selected.

RESULTS

The time that study subjects spend using devices ranged from 6 to 18 hours per day, amounting to 11.5±0.35 hours on average. According to the results of the Ocular Surface Disease Index (OSDI) questionnaire, 92.9% of study participants were revealed to have subjective symptoms of eye irritation. A decrease in TBUT was recorded in 30.8% of cases, the results of the Schirmer I test were decreased in 82.4% of the subjects. Significant changes in OSDI, Schirmer test and TBUT were obtained as the result of treatment. Changes in the indicators of staining and OCT meniscometry were not reliable.

CONCLUSION

The most significant risk factor of developing DED at a young age is regular, prolonged visual work with digital screens. The main symptoms are subjective manifestations and TBUT.

Evidence for a phenotypic switch in corneal afferents after lacrimal gland excision

Dry eye is a common cause of ocular pain. The aim of this study was to investigate corneal innervation, ongoing pain, and alterations in corneal afferent phenotypes in a mouse model of severe aqueous tear deficiency. Chronic dry eye was produced by ipsilateral excision of the extra- and intraorbital lacrimal glands in male and female mice. Tearing was measured using a phenol thread and corneal epithelial damage assessed using fluorescein. Changes in corneal ongoing ocular pain was evaluated by measuring palpebral opening ratio. Corneal axons were visualized using Nav1.8-Cre;tdTomato reporter mice. Immunohistochemistry was performed to characterize somal expression of calcitonin gene-related peptide (CGRP), the capsaicin sensitive transient receptor potential vanilloid 1 (TRPV1), and activating transcription factor-3 (ATF-3) in tracer labeled corneal neurons following lacrimal gland excision (LGE). LGE decreased tearing, created severe epithelial damage, and decreased palpebral opening, indicative of chronic ocular irritation, over the 28-day observation period. Corneal axon terminals exhibited an acute decrease in density after LGE, followed by a regenerative process over the course of 28 days that was greater in male animals. Corneal neurons expressing CGRP, TRPV1, and ATF3 increased following injury, corresponding to axonal injury and regeneration processes observed during the same period. CGRP and TRPV1 expression was notably increased in IB4-positive cells following LGE. These results indicate that dry eye-induced damage to corneal afferents can result in alterations in IB4-positive neurons that may enhance neuroprotective mechanisms to create resiliency after chronic injury.

Outcome Measures to Assess Dry Eye Severity: A Review

Outcome measures used to assess efficacy of dry eye therapeutics have not been consistently applied in clinical settings, nor have they been shown to correlate with functional outcomes. We propose that corneal staining, a clinically meaningful dry eye parameter, should be used as a standard objective outcome measure across all clinical trials evaluating dry eye treatments. We justify this based on evidence regarding its relationship to vision and vision related quality-of-life. In addition, corneal staining has been shown to correlate with ocular surface inflammation, a well elucidated aspect of dry eye pathophysiology and an active area in therapeutics research. No one outcome measure explored herein correlates perfectly to this heterogenous disease. However, there is mounting evidence showing the correlation between corneal staining and functional visual indices. We hope that future clinical trials will standardize corneal staining as a measure to determine the efficacy of interventions and justify their clinical utility.

Assessment of tear film osmolarity using the IPen® Vet osmometer in Pug and Shih-Tzu dogs with and without keratoconjunctivitis sicca

OBJECTIVE

To establish tear film osmolarity (TFO) values in Pugs and Shih-Tzus, with and without keratoconjunctivitis sicca (KCS).

ANIMALS STUDIED

A total of 82 adult dogs were evaluated.

PROCEDURE

The inclusion criteria for the healthy group was a Schirmer tear test (STT-1) ≥15 mm/min with no clinical signs of KCS, whereas those with KCS had clinical signs and a STT-1 ≤10 mm/min. All animals underwent complete ophthalmological evaluation prior to STT-1 and TFO. Student's t tests were used to compare STT-1 and TFO in KCS and healthy eyes as well as possible differences in TFO between breeds. In addition, a linear regression to model the relationship between the two variables (STT-1 and TFO) was performed. A P-value ≤ 0.05 was considered statistically significant.

RESULTS

STT-1 results were significantly lower (p = 0.0001) in the KCS group (4.46 ± 1.74) compared with the control group (18.80 ± 2.02). Mean TFO results were significantly higher in the KCS group (353.02 ± 16.58 mOsm/L) (p < 0.0001) compared with the control group (315.27 ± 6.15 mOsm/L). The formula Y = 365.059-2.625 * X significantly predicts (p < 0.001) the value of the variable Y (TFO mOsm/L) as a function of the variable X (STT-1 mm/min), with a coefficient of determination of 0.71.

CONCLUSIONS

The results revealed differences in TFO and STT-1 between KCS and healthy dogs. Additionally, STT-1 and TFO values were correlated with the aim to use STT-1 values to predict TFO values in brachycephalic breeds.

Development of low-cost planar electrodes and microfluidic channels for applications in capacitively coupled contactless conductivity detection (C4 D)

Electrochemical techniques are commonly applied to micro total analysis system (μTAS) devices mainly due to its high sensitivity and miniaturization capacity. Among many electrochemical techniques, capacitively coupled contactless conductivity detection (C⁴ D) stands out for not requiring direct electrode-solution contact, avoiding several problems such as electrolysis, bubble formation, and metal degradation. Furthermore, the instrumentation required for C⁴ D measurements is compact, low cost, and easy to use, allowing in situ measurements to be performed even by nonspecialized personal. Contrarily, the production of metallic electrodes and microchannels adequate for C⁴ D measurements commonly requires specialized facilities and workers, increasing the costs of applying these methods. We propose alternatives to batch manufacture metallic electrodes and polymeric microchannels for C⁴ D analysis using more straightforward equipment and lower-cost materials. Three devices with different dielectric layer compositions and electrode sizes were tested and compared regarding their analytical performance. The constructed platforms have shown a reduction of more than 64% in cost when compared to traditional techniques and displayed good linearity (R² ≥ 0.994), reproducibility (RSD ≤ 4.07%, n = 3), and limits of detection (≤0.26 mmol/L) when measuring standard NaCl samples. Therefore, the proposed methods were successfully validated and are available for further C⁴ D applications such as diagnosis of dry-eye syndrome.

Real-World Experience with Lifitegrast Ophthalmic Solution (Xiidra®) in the US and Canada: Retrospective Study of Patient Characteristics, Treatment Patterns, and Clinical Effectiveness in 600 Patients with Dry Eye Disease

Purpose

This study evaluated real-world treatment of dry eye disease (DED) with lifitegrast.

Patients and Methods

Ophthalmologists and optometrists treating patients with DED were invited to participate through a healthcare provider (HCP)-based panel. HCPs completed a provider survey and contributed data toward a chart review for up to five qualifying patients with DED who initiated lifitegrast ophthalmic solution (index date) between 01/01/2017 (US) or 01/01/2018 (Canada) and 06/30/2019. Patient demographics, treatments, clinical characteristics, and outcomes (ie, severity, signs, symptoms) were collected for the 6-month pre-index period and up to 12-months post-index.

Results

For this study, 517 HCPs contributed 600 patient charts. Among 554 and 281 patients with follow-up at 6 and 12-months post-index, 512 (92.4%) and 238 (84.7%) patients had ongoing lifitegrast treatment, respectively. Other DED-related treatments were less frequently used post-index with lifitegrast vs pre-index: over-the-counter artificial tear use (45.2% vs 75.5%), topical corticosteroids (3.8% vs 18.8%), any cyclosporine (3.0% vs 20.5%). At 3-months (n=571) and 12-months (n=320) post-index vs pre-index, fewer patients had eye dryness (47 [8.2%] and 16 [5.0%] vs 525 [87.5%]), blurred vision (28 [4.9%] and 11 [3.4%] vs 346 [57.7%]), ocular burning/stinging (25 [4.4%] and 8 [2.5%] vs 336 [56.0%]), depression (8 [1.4%] and 9 [2.8%] vs 55 [9.2%]), fatigue (4 [0.7%] and 1 [0.3%] vs 82 [13.7%]), and headache (1 [0.2%] and 0 vs 19 [3.2%]). At 3 and 12-months post-index vs pre-index, average corneal staining score was numerically lower (2.7 and 2.0 vs 6.5), and average Schirmer score (10.6 and 10 vs 6.3) and tear film break-up time (7.3 and 8.0 vs 4.8) higher.

Conclusion

The majority of patients had ongoing lifitegrast treatment 6-months post-index with reduction in overall treatment burden. Improvement in DED signs and symptoms, including QoL impacts, was evident at 3 months and up to 12 months after lifitegrast initiation.

Automated diagnosis and staging of Fuchs' endothelial cell corneal dystrophy using deep learning

Background

To describe the diagnostic performance of a deep learning algorithm in discriminating early-stage Fuchs’ endothelial corneal dystrophy (FECD) without clinically evident corneal edema from healthy and late-stage FECD eyes using high-definition optical coherence tomography (HD-OCT).

Methods

In this observational case-control study, 104 eyes (53 FECD eyes and 51 healthy controls) received HD-OCT imaging (Envisu R2210, Bioptigen, Buffalo Grove, IL, USA) using a 6 mm radial scan pattern centered on the corneal vertex. FECD was clinically categorized into early (without corneal edema) and late-stage (with corneal edema). A total of 18,720 anterior segment optical coherence tomography (AS-OCT) images (9180 healthy; 5400 early-stage FECD; 4140 late-stage FECD) of 104 eyes (81 patients) were used to develop and validate a deep learning classification network to differentiate early-stage FECD eyes from healthy eyes and those with clinical edema. Using 5-fold cross-validation on the dataset containing 11,340 OCT images (63 eyes), the network was trained with 80% of these images (3420 healthy; 3060 early-stage FECD; 2700 late-stage FECD), then tested with 20% (720 healthy; 720 early-stage FECD; 720 late-stage FECD). Thereafter, a final model was trained with the entire dataset consisting the 11,340 images and validated with a remaining 7380 images of unseen AS-OCT scans of 41 eyes (5040 healthy; 1620 early-stage FECD 720 late-stage FECD). Visualization of learned features was done, and area under curve (AUC), specificity, and sensitivity of the prediction outputs for healthy, early and late-stage FECD were computed.

Results

The final model achieved an AUC of 0.997 ± 0.005 with 91% sensitivity and 97% specificity in detecting early-FECD; an AUC of 0.974 ± 0.005 with a specificity of 92% and a sensitivity up to 100% in detecting late-stage FECD; and an AUC of 0.998 ± 0.001 with a specificity 98% and a sensitivity of 99% in discriminating healthy corneas from all FECD.

Conclusion

Deep learning algorithm is an accurate autonomous novel diagnostic tool of FECD with very high sensitivity and specificity that can be used to grade FECD severity with high accuracy.

Objective Imaging Diagnostics for Dry Eye Disease

Traditional diagnostic tests for dry eye disease (DED), such as fluorescein tear film break-up time and the Schirmer test, are often associated with poor reproducibility and reliability, which make the diagnosis, follow-up, and management of the disease challenging. Advances in ocular imaging technology enables objective and reproducible measurement of changes in the ocular surface, tear film, and optical quality associated with DED. In this review, the authors will discuss the application of various imaging techniques, such as, noninvasive tear break-up time, anterior segment optical coherence tomography, in vivo confocal microscopy, meibography, interferometry, aberrometry, thermometry, and tear film imager in DED. Many studies have shown these devices to correlate with clinical symptoms and signs of DED, suggesting the potential of these imaging modalities as alternative tests for diagnosis and monitoring of the condition.