A Simple Novel Technique of Infrared Meibography by Means of Spectral-Domain Optical Coherence Tomography: A Cross-Sectional Clinical Study

How Eyelid Changes May Impact on Tears

This article examines the impact of eyelid margin diseases on tear film composition and associated ocular surface disorders. It highlights the prevalence of blepharitis and meibomian gland dysfunction, discussing risk factors and diagnostic considerations. Various therapeutic approaches, including eyelid hygiene, antibiotics, and innovative treatments, are explored. Emphasizing the chronic nature of these conditions, the article underscores the need for patient compliance. Overall, it provides a concise overview of eyelid-related issues and potential management strategies.

Anterior segment optical coherence tomography meibography compared with keratograph meibography

PURPOSE

The aim of this study was to determine the feasibility of using readily accessible technology, anterior segment optical coherence tomography (AS-OCT), to detect and grade meibomian gland dropout and examine its interchangeability with the Oculus Keratograph 5M (K5M).

METHODS

A total of 30 participants (30 eyes) with a median age of 21 (range = 19-28 years) were recruited. Meibography was performed using two commercially available imaging devices to look at the structure of the meibomian glands and grade them subjectively in real time, and image analysis was used to quantify meibomian gland loss objectively. Gland loss as imaged by the two techniques was graded using the meiboscore grading schema. Test-retest reliability was determined with intraclass correlation coefficients (ICCs). Weighted kappa was used to evaluate agreement between the two imaging devices and four methods of image analysis. Spearman and Pearson correlation coefficients were used to determine the association of structural measurements between each of the techniques. The agreement between the two imaging techniques was determined with the Bland-Altman analysis.

RESULTS

Reliability of subjective grading was strong for AS-OCT (ICC: 0.92, 95% CI: 0.83-0.96, p < 0.001) and K5M (ICC: 0.96, 95% CI: 0.96-0.91, p = 0.001). Image analysis with ImageJ reliability was strong between the imaging devices (ICC: 0.84, 95% CI: 0.55-0.94, p < 0.001). Agreement between each subjective technique was fair, κ = 0.45 (95% CI: 0.17-0.73, p < 0.001) and a positive Spearman correlation was also observed (r = 0.52, p < 0.001). There was no significant difference between the mean meibomian gland loss measured with ImageJ between AS-OCT and K5M (0.92 ± 6.28, p = 0.26). The 95% limits of agreement were -12.45% to +14.04%.

CONCLUSION

These findings suggest subjective real-time grading of meibomian gland loss could be performed using readily available AS-OCT technology and that this method was interchangeable with the K5M.

The Use of Infrared Auto Refractometer for Meibomian Gland Imaging

Introduction This study proposes the utility of an infrared auto refractometer for meibography and compares miebographs obtained by an auto refractometer to meibographs obtained by a designated meibography machine. Methods A prospective observational comparative study of meibographs of patients with clinical signs of meibomian gland dysfunction (MGD) using a designated meibography machine and an infrared auto refractometer. Five masked, experienced interpreters graded the images of the two machines. The Kappa test was used to calculate Intra-rater and inter-rater agreements between the meibography machine and automated refractor grading of meibomian gland dysfunction. Results High-quality photos of all 30 eyes delineating the meibomian glands (MG) were successfully obtained with both the meibography machine and the autorefractor. Both methods had a good intra-rater agreement (κ= 0.667 to 0.784, average 0.738). Poor to fair interrater agreement was noticed in the grading of autorefractor images (k= -0.030 to 0.343, average 0.092) and poor to moderate agreements between investigators for meibography machine images (K= -0.016 to 0.420, average 0.173). Conclusion A commercially available auto refractometer could capture high-quality non-contact IR digital meibographs.

Prevalence of Meibomian Gland Atrophy in Patients Undergoing Cataract Surgery

PURPOSE

The aim of this study was to determine the prevalence of meibomian gland (MG) atrophy in a US-based population of patients presenting for cataract surgery.

METHODS

In this retrospective study, case records of 391 patients aged 50 years or older, who had undergone a preoperative cataract surgery workup with meibography, were included. The amount of atrophy in the lower eyelid was graded as described by Arita et al (grade 0 = no atrophy, grade 1 = 1%-33% atrophy, grade 2 = 34%-66% atrophy, and grade 3 = >66% atrophy), and the prevalence of MG atrophy was determined. Associations between MG atrophy and demography, comorbidities, and risk factors were evaluated.

RESULTS

Overall, 95.1% of patients (372/391) had MG atrophy ≥grade 1, with 50.4% (197/391) having grade 1, 25.8% (101/391) grade 2, and 18.9% (74/391) grade 3. MG atrophy had a statistically significant correlation with MG expressibility (R = 0.22; P = 0.001), but not with meibum grade (R = 0.103; P = 0.123) and telangiectasia (R = 0.014; P = 0.787). The prevalence of MG atrophy (≥grade 1) was comparable among patients who had previously been diagnosed with dry eye disease (DED) versus those who had not; however, the severity of MG atrophy was higher in patients with previous DED diagnosis (grade 2/3: 59% vs. 30.9%). Among patients with no previous history of DED, 18% (35/194) had moderate and 13% (25/194) had severe MG atrophy.

CONCLUSIONS

MG atrophy is common in patients presenting for cataract surgery evaluation, indicating potential underdiagnosis. Routine use of meibography during preoperative screening in cataract surgery patients may facilitate more timely and effective diagnosis and treatment.

Automation of dry eye disease quantitative assessment: A review

Dry eye disease (DED) is a common eye condition worldwide and a primary reason for visits to the ophthalmologist. DED diagnosis is performed through a combination of tests, some of which are unfortunately invasive, non‐reproducible and lack accuracy. The following review describes methods that diagnose and measure the extent of eye dryness, enabling clinicians to quantify its severity. Our aim with this paper is to review classical methods as well as those that incorporate automation. For only four ways of quantifying DED, we take a deeper look into what main elements can benefit from automation and the different ways studies have incorporated it. Like numerous medical fields, Artificial Intelligence (AI) appears to be the path towards quality DED diagnosis. This review categorises diagnostic methods into the following: classical, semi‐automated and promising AI‐based automated methods.

Common ocular findings in patients with acne rosacea

PURPOSE

To evaluate ocular surface manifestations in patients with acne rosecea (AR) and to find out main features indicating a propensity toward an association with disease diagnosis.

METHODS

Right eyes of consecutive 76 AR patients and 113 age-gender matched healthy subjects were enrolled. Ophthalmologic examinations including tear break-up time (t-BUT) and Schirmer-2 tests to analyze tear film insufficiency, optical coherence tomography (OCT)-assisted infrared meibography to analyze meibomian gland drop-out, and Ocular Surface Disease Index (OSDI) questionnaire were performed in all participants.

RESULTS

No statistically differences were found in visual acuity, intraocular pressure, central corneal thickness, and axial length assessments between the study and control eyes. Study eyes had more foreign body sensation, itching, dryness, hyperemia, conjunctival telangiectasia, and meibomitis (p ≤ 0.005, for all). Significantly higher t-BUT and Schirmer-2 tests; lower-eyelid and total OCT meibography; and OSDI scores were found in AR patients (p < 0.05, for all). Among all, only conjunctival telangiectasia (p = 0.001; OR:0.070, 95% CI:0.015-0.330) was found to be major independent predictor for AR diagnosis.

CONCLUSION

Detailed slit-lamp examination to detect any conjunctival telangiectasia seems to be crucial in recalcitrant dry eye cases, not to miss underlying AR. Especially, lower-eyelid OCT meibography score may be sensitively used for disease staging.

Anwendungsmöglichkeiten der optischen Kohärenztomographie beim trockenen Auge

Durch die stetige Weiterentwicklung und Verbesserung der Technik hat die optische Kohärenztomographie (OCT) in den letzten Jahren neue Möglichkeiten zur Beurteilung der Strukturen des vorderen Augenabschnittes eröffnet. Aufgrund der Darstellung kleinster Strukturen, wie beispielsweise des Tränenfilms, nimmt die OCT in der Diagnostik und Verlaufsbeurteilung des trockenen Auges eine immer wichtigere Rolle ein. Der vorliegende Beitrag gibt einen Überblick über die derzeitigen Einsatzmöglichkeiten der OCT beim trockenen Auge.

Safety profiles of terahertz scanning in ophthalmology

Terahertz (THz) technology has emerged recently as a potential novel imaging modality in biomedical fields, including ophthalmology. However, the ocular biological responses after THz electromagnetic exposure have not been investigated. We conducted a rabbit study to evaluate the safety profiles of THz scanning on eyes, at a tissue, cellular, structural and functional level. Eight animals (16 eyes) were analysed after excessive THz exposure (control, 1 h, 4 h, and 1 week after continuous 4-h exposure; THz frequency = 0.3 THz with continuous pulse generated at 40 µW). We found that at all the time points, the corneas and lens remained clear with no corneal haze or lens opacity formation clinically and histopathologically. No thermal effect, assessed by thermographer, was observed. The rod and cone cell-mediated electroretinography responses were not significantly altered, and the corneal keratocytes activity as well as endothelial viability, assessed by in-vivo confocal microscopy, was not affected. Post-exposed corneas, lens and retinas exhibited no significant changes in the mRNA expression of heat shock protein (HSP)90AB1), DNA damage inducible transcript 3 (DDIT3), and early growth response (EGR)1. These tissues were also negative for the inflammatory (CD11b), fibrotic (fibronectin and α-smooth muscle actin), stress (HSP-47) and apoptotic (TUNEL assay) responses on the immunohistochemical analyses. The optical transmittance of corneas did not change significantly, and the inter-fibrillar distances of the corneal stroma evaluated with transmission electron microscopy were not significantly altered after THz exposure. These results provide the basis for future research work on the development of THz imaging system for its application in ophthalmology.

Latest evidences on meibomian gland dysfunction diagnosis and management

Meibomian gland dysfunction (MGD) can be considered the leading cause of dry eye disease (DED) and one of the most common ophthalmic disorders found in clinical practice. The growing body of literature provides a substantial amount of information on this condition, but more efforts are needed to better interpret research data and to properly apply them to daily clinical practice., In this article, we reviewed the most recent publications on MGD diagnosis and management, focusing on the highest available level of evidence, provided by well-designed and well-reported studies on humans., Latest evidences on MGD diagnosis are mainly focused on imaging techniques, including meibography, optical coherence tomography (OCT), and in vivo confocal microscopy. Meibographic parameters, such as drop-out and glands' distortion, show great diagnostic accuracy, which accounts for their widespread use in clinical practice and research., Recent randomized controlled clinical trials on MGD treatment provided data on the role of antibiotics, steroids, essential fatty acids, intraductal meibomian gland probing, electronic heating devices and intense pulsed light therapy.

Tear 1H Nuclear Magnetic Resonance-Based Metabolomics Application to the Molecular Diagnosis of Aqueous Tear Deficiency and Meibomian Gland Dysfunction

PURPOSE

Meibomian gland dysfunction (MGD) is a major cause of signs and symptoms related to dry eyes (DE) and eyelid inflammation. We investigated the composition of human tears by metabolomic approaches in patients with aqueous tear deficiency and MGD.

METHODS

Participants in this prospective, case-control pilot study were split into patients with aqueous tear deficiency and MGD (DE-MGD [n = 15]) and healthy controls (CG; n = 20). Personal interviews, ocular surface disease index (OSDI), and ophthalmic examinations were performed. Reflex tears collected by capillarity were processed to 1H nuclear magnetic resonance (NMR) spectroscopy and quantitative data analysis to identify molecules by spectra comparison to library entries of purified standards and/or unknown entities. Statistical analyses were made by the SPSS 22.0 program.

RESULTS

Chemometric analysis and 1H NMR spectra comparison revealed the presence of 60 metabolites in tears. Differentiating features were evident in the NMR spectra of the 2 clinical groups, characterized by significant upregulation of phenylalanine, glycerol, and isoleucine, and downregulation of glycoproteins, leucine, and -CH3 lipids, as compared to the CG. The 1H NMR metabolomic analyses of human tears confirmed the applicability of this platform with high predictive accuracy/reliability.

CONCLUSIONS

Our key distinctive findings support that DE-MGD induces tear metabolomics profile changes. Metabolites contributing to a higher separation from the CG can presumably be used, in the foreseeable future, as DE-MGD biomarkers for better managing the diagnosis and therapy of this disease.

The role of meibography in ocular surface diagnostics: A review

The meibomian glands are lipid-secreting glands located in the tarsal plates, whose secretory products cover the tear film, thereby reducing evaporation as well as ensuring lubrication of the ocular surface. The meibomian glands can be visualized at different levels of magnification by infrared meibography, laser confocal microscopy, and optical coherence tomography. These imaging modalities have been subject to much research and progress in clinical practice and have shaped our current understanding of meibomian glands in health and disease. In this review, we explore the evolution of meibography over the past decades, the major contributions of various meibographic modalities, and discuss their clinical significance.

[In vivo Meibomian gland imaging techniques: A review of the literature (French translation of the article)]

Meibomian gland dysfunction (MGD) encompasses a group of complex pathologies of the ocular surface. They represent one of the main etiologies of dry eye but also one of the leading causes of consultation in ophthalmology. Conventional clinical tests (dry eye symptoms, tear film rupture time, glandular expressiveness assessment, or Schirmer's test) allow only an indirect assessment of Meibomian gland function and physiology. Various in vivo investigation methods have therefore been developed to image the meibomian glands such as meibography, optical coherence tomography, ultrasound or in vivo confocal microscopy. Some are accessible in clinical practice, while others remain in the field of clinical research. All these techniques aim to develop a direct structural analysis of the Meibomian glands to help in the diagnosis of DGM but also to better understand the pathophysiology of Meibomian glands. This review of the literature aims to provide an overview of existing imaging modalities and their interest in the evaluation of Meibomian glands and MGD.

The future of retinal imaging

PURPOSE OF REVIEW

This article reviews emerging technologies in retinal imaging, including their scientific background, clinical implications and future directions.

RECENT FINDINGS

Fluorescence lifetime imaging ophthalmoscopy is a technology that will reveal biochemical and metabolic changes of the retina at the cellular level. Optical coherence tomography is evolving exponentially toward higher resolution, faster speed, increased portability and more cost effective. Adaptive optics scanning laser ophthalmoscopy fluorescein angiography will provide unprecedented detail of the retinal vasculature down to the level of capillaries, enabling earlier and more sensitive detection of retinal vascular diseases.

SUMMARY

Continued developments in retinal imaging focus on improved resolution, faster speed and noninvasiveness, while providing new information on the structure-function relationship of the retina inclusive of metabolic activity at the cellular level.

Fourier-Domain OCT Imaging of the Ocular Surface and Tear Film Dynamics: A Review of the State of the Art and an Integrative Model of the Tear Behavior During the Inter-Blink Period and Visual Fixation

In the last few decades, the ocular surface and the tear film have been noninvasively investigated in vivo, in a three-dimensional, high resolution, and real-time mode, by optical coherence tomography (OCT). Recently, OCT technology has made great strides in improving the acquisition speed and image resolution, thus increasing its impact in daily clinical practice and in the research setting. All these results have been achieved because of a transition from traditional time-domain (TD) to Fourier-domain (FD) technology. FD-OCT devices include a spectrometer in the receiver that analyzes the spectrum of reflected light on the retina or ocular surface and transforms it into information about the depth of the structures according to the Fourier principle. In this review, we summarize and provide the state-of-the-art in FD-OCT imaging of the ocular surface system, addressing specific aspects such as tear film dynamics and epithelial changes under physiologic and pathologic conditions. A theory on the dynamic nature of the tear film has been developed to explain the variations within the individual compartments. Moreover, an integrative model of tear film behavior during the inter-blink period and visual fixation is proposed.

In vivo Meibomian gland imaging techniques: A review of the literature

Meibomian gland dysfunction (MGD) includes a group of complex disorders of the ocular surface. It represents one of the main etiologies of dry eye as well as one of the main reasons for patient visits to the ophthalmologist. Classic clinical tests (dry eye symptoms, tear film break-up time, evaluation of gland expressibility or Schirmer's testing) only provide an indirect assessment of the function of the Meibomian glands and the meibum. Various in vivo testing methods have therefore been developed to image the Meibomian glands, such as Meibography, optical coherence tomography, ultrasound, or even in vivo confocal microscopy. Some are accessible in clinical practice, while others are limited to the realm of clinical research. All of these techniques aim to develop a direct structural analysis of the Meibomian glands so as to assist in the diagnosis of MGD as well as to better understand the pathophysiology of the Meibomian glands. This review of the literature hopes to provide an overview of the current imaging modalities and their role in the evaluation of the Meibomian glands and MGD.

Diagnostic Test Efficacy of Meibomian Gland Morphology and Function

Meibomian gland dysfunction (MGD) is the leading cause of dry eye and proposed treatments are based on disease severity. Our purpose was to establish reliable morphologic measurements of meibomian glands for evaluating MGD severity. This retrospective, cross-sectional study included 100 MGD patients and 20 controls. The patients were classified into dry eye severity level (DESL) 1–4 based on symptoms and clinical parameters including tear-film breakup time, ocular staining and Schirmer I. The gland loss, length, thickness, density and distortion were analyzed. We compared the morphology between patients and controls; examined their correlations to meibum expressibility, quality, and DESL. Relative to controls, the gland thickness, density and distortion were elevated in patients (p < 0.001 for all tests). The area under the receiver operating characteristic curve was 0.98 (95% confidence interval [CI], 0.96–1.0) for gland loss, and 0.96 (CI 0.91–1.0) for gland distortion, with a cutoff value of six distorted glands yielding a sensitivity of 93% and specificity of 97% for MGD diagnosis. The gland distortion was negatively correlated to the meibum expressibility (r = −0.53; p < 0.001) and DESL (r = −0.22, p = 0.018). In conclusion, evaluation of meibomian gland loss and distortion are valuable complementary clinical parameters to assess MGD status.

A study of refractory cases of persistent epithelial defects associated with dry eye syndrome and recurrent corneal erosions successfully treated with cyclosporine A 0.05% eye drops

Background: Effective and tolerable therapeutic strategies for patients with refractory persistent epithelial defects (PEDs) are limited and generally provide poor outcomes. This retrospective case review describes four refractory cases of PEDs associated with recurrent corneal erosions (RCEs) and dry eye disease (DED), which were successfully treated with cyclosporine eye drops.

Methods: Patients were treated with cyclosporine A 0.05% eye drops twice a day for at least 12 months. At enrolling time, each patient was asked to suspend topical steroids or other eye drops used for ocular surface abnormalities with the exception of lubricants and eye washing. A complete evaluation of ocular surface symptoms was performed including the McMonnies Dry Eye Questionnaire, Ocular Surface Disease Index, slit-lamp biomicroscopy, fluorescein break-up time, the fluorescein staining of the cornea and conjunctiva (according to the Oxford grading system), the Schirmer I test, and the meibomian secretion after digital pressure application on the lids. This set of exams was carried out at baseline and repeated at all follow-up assessments.

Results: All participants that did not benefit from previous therapies, including corticosteroids tapering schedule, showed an important improvement in the clinical picture after two months with topical cyclosporine medication. Moreover, after 12 months of continuous therapy, all patients showed a clinical improvement in DED signs and symptoms, related to the absence of new RCE episodes. The treatment was well tolerated, and no adverse effects were reported.

Conclusion: Although a small number of cases were available of our analysis, the treatment with cyclosporine eye drops represents a promising approach in the management of refractory PEDs with associated ocular comorbidities, since it may reduce the RCE episodes and improve the tear film stability, in absence of systemic or local side effects.

The Bull's Eye Pattern of the Tear Film in Humans during Visual Fixation on En-Face Optical Coherence Tomography

The aim of the study was to define and characterize the optical behavior of the tear film during visual fixation in humans on en-face optical coherence tomography (OCT). We included 20 healthy participants, 60% female, aged from 25 to 42 years (33.05 ± 4.97 [mean ± SD]) and ten patients with severe dry eye, 50% female, aged from 26 to 42 years (33.7 ± 5.31). To perform high-resolution tear film imaging, participants were asked to gaze at the internal fixation point in the spectral-domain anterior segment OCT device, and meanwhile scanning session was executed at the following time-points after blinking: at the 2nd, 3rd, 4th, 5th, and 6th second. After one hour, OCT imaging was repeated (second session) by a different operator masked to the study to verify the reliability of results. During each measuring session, a pulse oximetry was used for continuously measuring the heart rate and oxygen saturation (SpO2%). A preliminary experiment was also performed to test the absence of geometric patterns from the anterior surface of a motionless artificial eye. OCT imaging showed a motionless, stable anterior surface of the artificial eye and in dry eye patients. Conversely, in the healthy participants of the study, a bull's eye pattern of the tear film was detected by OCT at the 2nd, 3rd, 4th, 5th, and 6th second after blinking, respectively, in 45%, 60%, 45%, 60%, and 40% of OCT scans during the first session, and in 35%, 65%, 65%, 60%, and 35% of cases in the second session. Overall, a total of 200 OCT scans were performed in normal human population. A significant correlation was found between the novel tear film pattern and heart rate during the first and the second session (p < 0.01) in healthy eyes. Conversely, no correlation was revealed with SpO2%. Intraclass correlation (ICC) analysis for OCT imaging of the tear film revealed a statistically significant reproducibility of the results (ICC = 0.838; p < 0.01), indicating the high level of reliability of the method, independently of heart rate and SpO2% variables. There exists a novel, geometric pattern of the tear film during visual fixation detectable by en-face OCT, which is mainly evident as heart rate increases. Its discovery implies in turn the presence of a specific vibration (or imperceptible motion) of the tear film that, at present, is not recognized and corrected by the OCT software (in image postprocessing) unlike other eyeball movements.

[Modified meibography in malignant eyelid tumors of epithelial origin]

INTRODUCTION

Eyelid tumors can be diagnosed using various diagnostic techniques. However, capability of existing methods for determining the type and margins of the tumor at the preoperative stage remains insufficiently studied.

PURPOSE

To improve the noncontact infrared meibography technique and determine its diagnostic capabilities for studying structural changes in meibomian glands in malignant eyelid tumors of epithelial origin.

MATERIAL AND METHODS

The study included 49 people (66 eyelids), among which 21 (21 eyelids) with malignant eyelid tumors, 11 - with benign eyelid tumors (11 eyelids), and 17 (34 eyelids) comprised the control group. The mean age of patients was 64.8±1.56 years. Meibomian glands of the lower eyelids were photographed in infrared light. Receiver-operating characteristic (ROC) curves were constructed to estimate the sensitivity and specificity of the method.

RESULTS

Modified meibography showed 100% sensitivity and 90% specificity in the differential diagnosis of malignant and benign eyelid tumors in 32 patients. Unlike other methods, the modified meibography technique can clarify the margins of tumor growth, which is considered when planning the resection volume.

CONCLUSION

Modified meibography can indicate the margins of tumor invasion; it can be successfully used in the differential diagnostics of malignant eyelid tumors of epithelial origin and benign eyelid tumors.

Corneal endothelium features in Fuchs' Endothelial Corneal Dystrophy: A preliminary 3D anterior segment optical coherence tomography study

Purpose

To evaluate the feasibility of 3D anterior segment optical coherence tomography (AS-OCT) for the detection of corneal endothelial features in patients with Fuchs’ Endothelial Corneal Dystrophy (FECD).

Methods

Twenty patients with clinical diagnosis of FECD (group A), and 20 control subjects (group B) were enrolled. In all patients a complete ophthalmological examination was performed, including best corrected visual acuity (BCVA), slit lamp examination for subjective grading of FECD and corneal endothelial specular microscopy. A 512x128 AS-OCT cube centered on the corneal apex was performed, and then the inner surface of the cornea was visualized and analyzed individually.

Results

Overall, the study participants were adults (mean age was 57.35 ± 8.45 years [mean ± SD] 80% female) with a BCVA ranged from 1.3 to 0 LogMAR. The OCT analysis disclosed three different patterns of the corneal endothelium (1, 2, 3) according to the signal distribution and the level of reflectivity: a homogenous, hypo-reflective surface (pattern 1); the presence of hyper-reflective orange-yellowish points (pattern 2); and a mottled appearance with a variable number of hyper-reflective areas (pattern 3). The distributions of these morphological models in the two populations were as follows: patterns 1, 2 and 3 were observed respectively in 0%, 80%, and 20% of patients in group A, and in 80%, 20% and 0% of subjects in group B. Correlation analysis unveiled a positive relationship between OCT corneal endothelium reflectivity and the clinical severity score (assessed with biomicroscopy), as well as an inverse relationship between the OCT pattern and the integrity of corneal endothelium.

Conclusion

3D AS-OCT is a useful tool in investigation of endothelial features and therefore may represent a valuable support in the setting of FECD diagnosis and staging.

Ocular surface and respiratory tract damages from occupational, sub-chronic exposure to fluorspar: case report and other considerations

OBJECTIVES

To report the ocular surface and respiratory tract damages due to a sub-chronic (3 months), occupational exposure to fluorspar dust in case of inconsistent use of personal protective equipment.

METHODS

A 50-year-old man was referred to our clinic with bilateral conjunctival injection, ocular foreign body sensation and symptoms of ocular discomfort. He reported having 3 days before an urgent hospital admission for dyspnoea with odynophagia, hyposmia, nausea, vomiting, headache and asthenia. Otorhinolaryngological examination revealed a severe hypertrophic rhinopharyngitis and a significant decrease in overall sensitivity to olfactory stimuli. General anamnesis was negative for previous diseases or medication use.

RESULTS

Ocular examination revealed a diffuse injection of the ocular surface with some areas of conjunctival and limbal ischaemia, a best-corrected visual acuity of 20/25 in both eyes, an intraocular pressure of 23 and 21 mmHg, respectively, in the right and in the left eyes, and a normal fundus oculi. Assessment of the tear film and ocular surface showed the presence of dry eye disease. Based on medical history and clinical tests, initial diagnostic hypothesis was ocular surface burn due to chemical exposure, i.e. to fluorspar. Therefore, anterior segment fluorescein angiography was performed to confirm the extension of conjunctival and limbal ischaemia. Thus, ocular ischaemia was detected in approximately 10 clock hours of limbus and in 50% of conjunctiva.

CONCLUSIONS

The present work remarks the importance of using protective equipment for preventing ocular and respiratory tract damages in workers occupationally exposed to the 'acid-grade fluorite'.

Morphological evaluation for diagnosis of dry eye related to meibomian gland dysfunction

The evaluation of morphological changes of the acini in the meibomian glands is important for the diagnosis and management of dry eye related to meibomian gland dysfunction. While several tools have been developed to detect meibomian gland structure, infrared imaging is generally used in clinical settings. Unlike the lipid component analysis of tear film in which quantitative analysis is possible, the meibomian glands are limited to qualitative analysis because of the low image quality of the diagnostic tools. This review describes diagnostic tools, especially in terms of morphological evaluation of the acini, which are visualized by the existence of lipid within them.

Risk factors for severe Meibomian gland atrophy in a young adult population: A cross-sectional study

PURPOSE

Assess potential risk factors for severe Meibomian gland atrophy (SMGA) in a young adult population.

METHODS

Cross-sectional study using medical history and ocular surface examination to evaluate relationships with study outcomes: SMGA, tear lipid layer (TLL) thickness, non-invasive (NITBUT) and fluorescein (FTBUT) tear breakup times, and symptoms using the Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire.

RESULTS

One hundred one participants (101; 202 eyes; Age: mean±SD = 22.3±4.0 years) completed the study. Hormonal birth control (HBC) use was the only significant risk factor for SMGA (p = 0.028). Female HBC users had 4.8 times greater odds of having SMGA compared to female HBC non-users (p = 0.028), but the odds of having SMGA was similar between female HBC non-users and males (p = 0.885). Multivariable analysis suggested that the relationship between SMGA and TLL thickness was dependent on HBC use. Compared to female HBC non-users without SMGA, TLL thickness for HBC users was estimated to be 10 nm thinner if SMGA was absent (p = 0.007) and 21 nm thinner if SMGA was present (p<0.001). SMGA status had no significant impact on TLL thickness among female HBC non-users (p = 0.552). The effect of TLL thickness on FTBUT was small but significant (p = 0.026). TLL thickness was not significantly associated with NITBUT (p = 0.349). Neither FTBUT nor NITBUT was significantly associated with the SPEED score.

CONCLUSION

HBC use may be associated with SMGA, supporting the hypothesis that SMGA could lead to thinner TLL. However, less evidence was present to support that thin TLL could lead to clinically detectable tear film instability and subsequently to increased ocular dryness symptoms. Further investigation with a larger sample size is warranted to confirm these findings.

Resolution of pinguecula-related dry eye disease after argon laser photocoagulation

Purpose

To describe an unusual case of unilateral, chronic symptoms and signs of dry eye, and recurrent episodes of ocular irritation related to pinguecula, which were refractory to prior medical treatments, successfully treated with argon laser photocoagulation.

Methods

A 36-year-old man presented with an elevated yellowish mass on his conjunctiva in his left eye, which was associated with dry eye symptoms and general discomfort, such as “tightening sensation” and “stiffness”. On clinical assessment, the left eye revealed a mild conjunctival injection, a fluorescein break-up time (FBUT) of 3.5 s, an abnormal fluorescein staining, and a Schirmer I test of 5 mm. Optical coherence tomography (OCT) imaging evidenced a height at the most elevated point of the pinguecula of 740 µm. The patient underwent argon-laser photocoagulation.

Results

After 2 weeks postoperatively, no residual of pinguecula or focal injection of the conjunctiva was detected by slit-lamp biomicroscopy and there was a significant improvement of clinical symptoms and signs: Schirmer I test and FBUT increased to 12 mm and >10 s, respectively, and fluorescein staining was absent. OCT imaging revealed a smooth structure of conjunctival contour, with a height of 404 µm. According to an ex juvantibus line of reasoning, definitive diagnosis was pinguecula-related dry eye disease.

Conclusion

Based on the concept that tear film instability and inflammation are two key components of the pathogenesis of dry eye, we coined the term “pinguecula-related dry eye disease,” which can be successfully treated by a complete, accurate removal of the lesion with argon laser photocoagulation.