Meibography-Guided Electroepilation for Congenital Distichiasis: A Novel Surgical Technique.

PURPOSE: Congenital distichiasis is managed either by ablation, using laser, cryotherapy, or electroepilation, or by surgical excision with mucous membrane grafting. Ablative procedures are usually blind as the exact depth of distichiatic eyelashes is unknown. The described surgical technique utilizes meibography for imaging the root and depth of distichiatic eyelashes that aided in performing electroepilation. METHODS: Six patients (n = 24 eyelids; mean age 15.5 ± 12.2 years) underwent infrared meibography (Oculus Keratograph 5 M) and noninvasive tear breakup time prospectively. Eyelashes were electroepilated using a premarked needle inserted at a depth based on meibography findings in 4 patients. Surgical success was defined as no distichiatic eyelash regrowth and functional success was defined as the resolution of symptoms at a minimum of 3 months of follow-up. RESULTS: All 6 patients had all 4 eyelids involved to varying degrees, with a total of 230 distichiatic eyelashes. The median number of distichiatic eyelashes was 9 in the upper eyelids and 4.5 in the lower eyelids. Meibography revealed visible distichiatic eyelash roots in 70% of eyelashes in the upper eyelid and 87.8% in the lower eyelid, respectively. The median eyelash root depth was 2.7 mm (mean 2.9 mm, range 1.8-5.4 mm). The mean noninvasive tear breakup time was 12.2 seconds despite absent or rudimentary meibomian gland segments seen on meibography. The anatomical success was 75% (12/16 eyelids), and functional success was 87.5% (7/8 eyes) at a median follow-up of 5.5 months. CONCLUSION: Preoperative infrared meibography in eyelids with congenital distichiasis helps estimate the eyelash depth and can be used to guide eyelash ablation procedures.

Evaluation of tear meniscus height and lipid layer patterns in the tear film in domestic cats: An observational study.

Background: Healthy vision in humans and animals requires a stable tear film. The environmental factor could affect the status of the tear film. Therefore, assessing the tear film in animals is essential to avoid visual system disturbance. Aim: The current research used a noninvasive device to evaluate the tear meniscus height (TMH) and lipid layer pattern (LLP) in domestic cats. In addition, the scores were compared with those of humans with healthy eyes. Methods: Fifty-four domestic cats (28 males and 26 females; mean ± SD = 13.9 ± 18.2 months) were randomly selected and included in the study. The cats were healthy, without any ocular disorders or diseases. Fifty-four healthy eye subjects (27 males and 27 females; mean ± SD = 25.6 ± 5.1 years) were randomly recruited and took part in the study for comparison. EASYTEAR View+ was used, for the first time, to assess the tear film parameters on the right eye of each subject. The examiner allowed a 5-minute gap between the tests. Each test was performed by the same examiner three times, followed by calculating the mean scores. Results: Significant differences (Mann-Whitney U test) were found in the median scores of LLP (p = 0.009) between cats and subjects with healthy eyes. The median TMH score was higher in cats (0.18 mm) than in humans (0.14). However, no significant difference (Mann-Whitney U Test, p = 0.210) exists in the TMH scores between cats and humans. The LLP analysis indicated that a dense white-blue lipid layer (grade 4 or D; lipid layer thickness, LLT, = approximately 80 nm) was predominant in both cats (N = 24, 44.4%) and humans (N = 29, 53.7%). In comparison, variable colors lipid layer (grade 5 or E; LLT = 90-140 nm) was a minority in cats (N = 5, 9.3%) and common in humans (N = 16, 29.6%). The statistical analysis indicated medium correlations between cats' TMH and LLP scores (r = 0.431, p < 0.01) and between age and TMH scores in humans (r = 0.440, p < 0.01). In addition, it indicated a weak correlation (r = 0.291, p < 0.05) between the LLP scores in cats and humans. Conclusion: Assessing animals' tear film is essential to avoid any ocular disorders. EASYTEAR View+ is efficiently used to evaluate domestic cats' TMH and LLP. Cats have thicker lipid layers and longer TMH comparable to those reported for humans with healthy eyes.

Assessment of lipid layer patterns in domestic dogs and rabbits: an observational study.

Background: Maintaining a stable tear film is crucial for having healthy human and animal vision. Animals are expected to have thicker lipid layers than humans due to living in high-temperature and humid environments. Aim: The study aimed to evaluate the lipid layer patterns (LLPs) in Arabian dogs and rabbits using a non-invasive, practical, and easy-to-use device and compare them to humans with healthy eyes. Methods: The study included 75 domestic Arabian dogs (42 males and 33 females; mean ± SD = 6.1 ± 12.7 months) and 75 rabbits (37 males and 38 females; mean ± SD = 3.1 ± 3.4 months). In addition, 75 individuals with healthy eyes (39 males and 36 females; mean ± SD = 25.7 ± 5.0 years) were included for comparison. EASYTEAR View+ assessed the LLP in each animal's and individual's right eye. Results: The median LLP grades significantly differed between dogs and humans (Mann-Whitney U test, p < 0.001). Similarly, the LLP grades differed significantly between rabbits and humans (Mann-Whitney U test, p < 0.001). No significant difference (Mann-Whitney U test) in the LLP grades between dogs and rabbits was found. The analysis indicated that most dogs had either an A (34.7%) or a B grade (37.3%). Similarly, rabbits had predominantly A or 1 (46.7%) and B (30.7%) grades. On the other hand, humans had predominantly D (53.3%) and E (30.7%) grades. Conclusion: The EASYTEAR View+ has been employed to assess LLP in dogs and rabbits, and the measurements were compared to those of humans with normal ocular health. Dogs and rabbits have thinner lipid layers than healthy humans.

Association between dryness sensation and ocular surface temperature and conjunctival blood flow in soft contact lens wearers.

PURPOSE: To investigate the association between dryness, ocular surface temperature (OST), and conjunctival blood flow (CBF) in soft contact lens (SCL) wearers after airflow stimulation. METHODS: After recruiting 21 SCL wearers (mean age, 25.3 ± 4.2 years), subjects used two different daily disposable silicone hydrogel SCLs (narafilcon A and delefilcon A lenses). On three of four measurement days, excluding the first, OST, CBF, tear meniscus height (TMH), and non-invasive tear break-up time (NIBUT) were measured after airflow stimulation at a rate of 3 m/s for 10 min. The measurements were conducted without SCLs on the first and second days, and with different SCLs on the third and fourth days. Dryness was evaluated using the visual analogue scale (VAS). These parameters were compared between the two types of SCLs, and their association with the dryness sensation was then investigated. RESULTS: Dryness was significantly weakly correlated with OST (r = -0.375, p < 0.05) and CBF (r = 0.339, p < 0.05). TMH, NIBUT, and VAS scores for dryness with the delefilcon A lens (0.15 ± 0.05 mm, 3.7 ± 01.7 s and 29.4 ± 16.9) were significantly higher, longer, and lower, respectively, than those with the narafilcon A lens (0.12 ± 0.05 mm, 2.3 ± 1.7 s and 35.9 ± 17.0; p < 0.05, p < 0.01 and p < 0.01). The changes in the OST and CBF between with and without the delefilcon A lens (-0.36 ± 0.35 °C and 0.99 ± 0.19) were significantly small compared to the narafilcon A lens (-0.60 ± 0.42 °C and 1.11 ± 0.21; p < 0.01 for both comparisons). CONCLUSION: Dryness was correlated with OST and CBF, which indicates that when dryness was high, OST was low and CBF was high. These results suggest that OST and CBF assessments are effective for evaluating dryness sensation.

The impact of dry eye disease on retinal image quality in children.

BACKGROUND AND OBJECTIVES: Dry eye disease (DED) is increasingly prevalent, resultinginhigher morbidityamong children. This study evaluates the impact of DED severity on visual quality using double-pass technology, focusing on dynamic observation of the ocular light scatter in pediatric DED cases. METHOD: In this non-interventional, cross-sectional study, a mild DED group (37 cases, 37 eyes), a moderate DED group (40 cases, 40 eyes), and a control group of healthy children (35 cases, 35 eyes) were examined. Measurements included the Schirmer I test, tear film break-up time (BUT), and vision-related quality of life assessments using the Modified Ocular Surface Disease Index (OSDI) questionnaires. Participants underwent visual quality analysis using double-pass technology, which measured the modulation transfer function cut-off frequency value, Strehl ratio, objective scatter index (OSI), and OQAS-II value (OQAS-II value 100%, OQAS-II value 20%, and OQAS-II value 9%) under natural conditions. Additionally, dynamic changes in OSI post-blinking, Tear film mean-OSI , and the corresponding standard deviation OSI were recorded. RESULTS: Statistically significant differences were observed among the groups in modulation transfer function cutoff, Strehl ratio, OSI, OQAS-II value 100 %, OQAs-II value 20 %, OQAs-II value 9 %, tear film mean OSI, and standard deviation OSI (P < 0.05). As DED severity increased, tear film mean OSI significantly rose, while modulation transfer function cutoff, strehl ratio, OQAS-II value 100 %, OQAS-II value 20 %, OQAS-II value 9 % notably declined. All optical quality parameters were correlated with BUT, with no association observed with age, sex, or Schirmer I test. CONCLUSION: Dual-channel technology objectively assesses visual quality in pediatric DED, demonstrating that tear film scattering significantly affects retinal imaging and visual quality in children with DED.

Models for Meibomian gland dysfunction: In vivo and in vitro.

Meibomian gland dysfunction (MGD) is a chronic abnormality of the Meibomian glands (MGs) that is recognized as the leading cause of evaporative dry eye worldwide. Despite its prevalence, however, the pathophysiology of MGD remains elusive, and effective disease management continues to be a challenge. In the past 50 years, different models have been developed to illustrate the pathophysiological nature of MGD and the underlying disease mechanisms. An understanding of these models is crucial if researchers are to select an appropriate model to address specific questions related to MGD and to develop new treatments. Here, we summarize the various models of MGD, discuss their applications and limitations, and provide perspectives for future studies in the field.

Efficacy and safety of trigeminal parasympathetic pathway stimulation for dry eye: A systematic review and meta-analysis.

This study aimed to investigate the efficacy and safety of trigeminal parasympathetic pathway (TPP) stimulation in the treatment of dry eye. A comprehensive search for randomized clinical trials was performed in seven databases (MEDLINE, Embase, CENTRAL, etc.) up to 28 February 2023. After screening the suitable studies, the data were extracted and transformed as necessary. Data synthesis and analysis were performed using Review Manager 5.4, and the risk of bias and quality of evidence were evaluated with the recommended tools. Fourteen studies enrolling 1714 patients with two methods (electrical and chemical) of TPP stimulation were included. Overall findings indicate that TPP stimulation was effective in reducing subjective symptom score (standardized mean difference [SMD], -0.45; 95% confidence interval [CI], -0.63 to -0.28), corneal fluorescence staining (mean difference [MD], -0.78; 95% CI, -1.39 to -0.18), goblet cell area (MD, -32.10; 95% CI, -54.58 to -9.62) and perimeter (MD, -5.90; 95% CI, -10.27 to -1.53), and increasing Schirmer's test score (SMD, 0.98; 95% CI, 0.65 to 1.31) and tear film break-up time (SMD, 0.57; 95% CI, 0.19 to 0.95). Compared to inactive or low-activity stimulation controls, it has a higher incidence of adverse events. Therefore, TPP stimulation may be an effective treatment for dry eye, whether electrical or chemical. Adverse events are relatively mild and tolerable. Due to the high heterogeneity and low level of evidence, the current conclusions require to be further verified.

Effect of upper eyelid blepharoplasty on the ocular surface, tear film, and corneal microstructure.

PURPOSE: This study aimed to investigate the effect of upper eyelid blepharoplasty with the removal of the skin and a strip of orbicularis oculi muscle on the ocular surface, tear film, and dry eye-related symptoms. METHODS: Twenty-two eyes of 22 consecutive patients operated by a single surgeon (21 females; mean age, 61 years; age range, 41-75 years) were included. All subjects completed the Ocular Surface Disease Index questionnaire, underwent in vivo confocal microscopy, tear film breakup time measurements, the Schirmer test with anesthesia, and fluorescein and lissamine green staining measurements before, 1 month, and 6 months after upper blepharoplasty alone with preseptal orbicularis excision. RESULTS: A significant increase in Ocular Surface Disease Index, and corneal fluorescein and lissamine green staining and a significant decrease in tear film breakup time were observed after 1 month (p=0.003, p=0.004, p=0.029, and p=0.024 respectively) and 6 months (p=0.001 for all findings). No significant difference in the Schirmer test score was observed during the follow-up. None of the in vivo confocal microscopy parameters showed significant changes during the study. CONCLUSIONS: An increase in dry eye symptoms and a decrease in tear film stability along with ocular surface staining were observed in patients undergoing upper eyelid blepharoplasty.

Thermal relations in sled dogs before and after exercise.

Regulation of internal body temperature (Tb), or thermoregulation, is an evolutionarily conserved trait that places demand on basal metabolic rate of endothermic animals. Across species, athletes generate increased quantities of heat in comparison to their nonathletic counterparts and, therefore, must mediate physiological unbalance by upregulating the effectiveness of their heat dissipation abilities. Canine athletes are no exception to this phenomenon, however, with literature denoting body temperatures lower than nonathletic canines, it is clear they must possess adaptations to mitigate this demand. With VO2 max measurements of more than 200 mL/kg/min in sled dogs with mild training to 300 mL/kg/min in highly trained animals, sled dogs are a prime example of athleticism in canines. Seeking to determine correlations between Tear and body mass, morphology, and age of canine athletes, core body temperature (Tb) was measured with an instant ear thermometer, using Tear as a correlate before and after a 2-mile run. In addition, we employed thermal imaging analysis to capture body-wide heat dissipation patterns in sled dogs, and focused on thermal variation of mouth (Tmouth), nose (Tnose), and eyes (Teye). Furthermore, we looked at correlations between thermal variability across these four tissues and head morphology of each dog. Tear was consistently the highest temperature across all tissues measured, with a 1.5°C increase between pre- to postexercise (p < 0.001). Thermal imaging revealed significant positive correlations between Tmouth and body mass 15 min postexercise (p = 0.0023) as well as significantly negative correlations between Tnose and body mass at before exercise (p = 0.0468), Teye and nose length after run (p = 0.0076), and Tmouth and nose length after run (p = 0.0110). As body temperature rises during exercise, it becomes increasingly important to regulate blood flow throughout the body to supply working tissues with oxygen. This demand is offset by the role of the snout in evaporative cooling through panting, functioning as a prime location for heat dissipation and therefore maintaining significant relationships with many other vascularized tissues.

Impact of stress on the tear production of healthy cats.

OBJECTIVES: This study aimed to determine the impact of acute stress on tear production in companion cats to provide a basis for minimizing stress-inducing stimuli during ophthalmic evaluations. METHODS: A total of 24 healthy owned cats (12 males, 12 females) of mixed breed, aged 8 months to 7 years, with no history of ocular diseases, were selected for the study. The cats were housed in individual cages under controlled conditions for 6 days. The Schirmer tear test-1 (STT-1) was performed in the morning (between 9:00 am and 11:00 am) using test strips from the same batch. The first test (without stress) was conducted on the fifth day of acclimation, and the second test (with stress) on the sixth day. The stress stimulus consisted of recordings of barking dogs, cats fighting and the murmuring of people. For both tests, the heart rate was assessed with a stethoscope before, during and after the tests, and the environmental stress level was also evaluated. Results are presented as mean ± SD and 95% confidence interval (CI). RESULTS: The study found that STT-1 values were significantly higher (P = 0.009) with stress (22.2 ± 6.0 mm/min [95% CI 19.9-24.6]) than without stress (17.5 ± 6.9 mm/min [95% CI 14.8-20.2]). Similarly, the heart rate was significantly higher (P = 0.028) in stress vs non-stress conditions (213.4 ± 37.5 beats per minute [bpm] [95% CI 198.7-228.1] vs 171.5 ± 28.6 bpm [95% CI 160.3-182.7], respectively), and the environmental stress score was significantly higher (P <0.001) in stress vs non-stress conditions (3.3 ± 0.5 [95% CI 3.1-3.5] vs 1.2 ± 0.4 [95% CI 1.1-1.4], respectively). CONCLUSIONS AND RELEVANCE: Stress increased tear production in cats. Although the mean STT-1 value obtained under stress conditions was within the normal range, stress can influence the test results. The use of cat friendly handling techniques facilitates execution of the STT-1.

End-of-day assessment of asymptomatic versus highly symptomatic soft contact lens wearers.

PURPOSE: To investigate differences in key clinical parameters between asymptomatic and highly symptomatic soft contact lens (CL) wearers after 14 h of wear. METHODS: In this pilot investigation, Phase 1 identified asymptomatic (CLDEQ-8 score ≤ 7) and highly symptomatic (CLDEQ-8 score ≥ 20) subjects after fitting with nelfilcon A CLs. Phase 2 investigated the following over a single nelfilcon A CL-wearing day (14 ± 2 h): blinking characteristics, tear meniscus height (TMH), non-invasive tear break-up time (NIBUT), tear film osmolarity and eyelid margin staining. Parameters for the two groups were compared using linear mixed models and post-hoc testing. The relationship between comfort scores and the clinical parameters was also investigated. RESULTS: Overall, 161 and 42 subjects were enrolled into Phase 1 and 2, respectively. Twenty-five asymptomatic and 17 symptomatic subjects completed Phase 2. Lower eyelid TMH was decreased after 14 h in symptomatic compared with asymptomatic subjects (least square mean [LSM] difference -0.04 mm, 95% CI: -0.07, -0.01). Osmolarity was lower in symptomatic than in asymptomatic subjects at fitting (LSM difference -9.89, 95% CI: -18.91, -0.86). Upper eyelid margin staining was greater after 14 h in symptomatic than in asymptomatic subjects (LSM difference 0.53, 95% CI: 0.01, 1.05) and greater after 14 h than baseline in the symptomatic group (LSM difference 0.61, 95% CI: 0.16, 1.07). There was a significant relationship between comfort and upper eyelid margin staining (r = -0.40, 95% CI: -0.63, -0.11) and blink rate (r = -0.31, 95% CI: -0.57, -0.003). CONCLUSION: The potential parameters most effective in differentiating asymptomatic from symptomatic wearers were upper eyelid margin staining and lower TMH. The parameter with the strongest relationship to comfort was upper eyelid margin staining, where higher comfort scores were associated with lower levels of staining.

Ocular effects of exposure to low-humidity environment with contact lens wear: A pilot study.

PURPOSE: To compare the ocular effects of exposure to a low-humidity environment with and without contact lens (CL) wear using various non-invasive tests. METHODS: Fourteen habitual soft CL wearers were exposed to controlled low humidity (5% relative humidity [RH]) in an environmental chamber for 90 min on two separate occasions. First, when wearing their habitual spectacles and then, on a separate visit, when wearing silicone hydrogel CLs that were fitted specifically for this purpose. All participants had adapted to the new CL prior to data collection. Three non-invasive objective measurements were taken at each visit: blinking rate, objective ocular scatter (measured using the objective scatter index) and ocular surface cooling rate (measured using a long-wave infrared thermal camera). At each visit, measurements were taken before the exposure in comfortable environmental conditions (RH: 45%), and after exposure to environmental stress (low humidity, RH: 5%). RESULTS: CL wearers showed increased blinking rate (p < 0.005) and ocular scatter (p = 0.03) but similar cooling rate of the ocular surface (p = 0.08) when compared with spectacle wear in comfortable environmental conditions. The exposure to low humidity increased the blinking rate significantly with both types of corrections (p = 0.01). Interestingly, ocular scatter (p = 0.96) and cooling rate (p = 0.73) were not significantly different before and after exposure to low humidity. There were no significant two-way interactions between correction and exposure in any of the measurements. CONCLUSIONS: CLs significantly increased the blinking rate, which prevented a quick degradation of the tear film integrity as it was refreshed more regularly. It is hypothesised that the increased blinking rate in CL wearers aids in maintaining ocular scatter quality and cooling rate when exposed to a low-humidity environment. These results highlight the importance of blinking in maintaining tear film stability.

New advances in medical management of dry eye: optimizing treatment strategies for enhanced relief.

PURPOSE: Dry eye disease (DED) is a prevalent ocular surface disease that is conventionally characterized by tear film hyperosmolarity and instability. This review presents a summarized classification of DED, followed by a comprehensive discussion of the most recent topical and systemic medications and clinical recommendations for selecting the most appropriate option for each patient. METHODS: An extensive literature search was conducted on electronic databases, such as PubMed, Scopus, and Web of Science, using keywords including "dry eye syndrome," "ocular surface disease," "medical management," "artificial tears," "topical immunomodulators," and "meibomian gland dysfunction." RESULTS: The underlying reasons for DED can range from insufficient aqueous tear production to increased tear evaporation. Recent literature has provided a more in-depth understanding of the pathophysiology of DED by examining the tear film's lipid, aqueous, and mucin layers. However, despite these advancements, medical management of patients with symptomatic DED has not fully reflected this modernized knowledge of its pathophysiology. CONCLUSION: To develop a rationalized strategy for treating DED, it is crucial to have updated knowledge of therapeutic options, their mechanisms of actions, and indications based on the DED type and underlying causes.

Rethinking Sjögren Beyond Inflammation: Considering the Role of Nerves in Driving Disease Manifestations.

ABSTRACT: Sjögren syndrome (SS) is a chronic inflammatory autoimmune disease characterized by destruction of mucosal glands resulting in dry eye and dry mouth. Ocular presentations can be heterogenous in SS with corneal nerves abnormalities that are structural, functional, or both. Some individuals present with corneal hyposensitivity, with a phenotype of decreased tear production and epithelial disruption. Others present with corneal hypersensitivity, with a phenotype of neuropathic pain including light sensitivity and pain out of proportion to signs of tear dysfunction. A similar correlate can be found outside the eye, with dry mouth predominating in some individuals while pain conditions predominate in others. Understanding how nerve status affects SS phenotype is an important first step to improving disease management by targeting nerve abnormalities, as well as inflammation.

New Insights into the Molecular Structure of Tear Film Lipids Revealed by Surface X-ray Scattering.

The tear film lipid layer (TFLL) is a unique biological membrane that serves a pivotal role in the maintenance of ocular surface health. Reaching an overarching understanding of the functional principle of the TFLL has been hampered by a lack of insights into the structural and functional roles played by individual lipid classes. To bridge this knowledge gap, we herein focus on studying films formed by principal lipid classes by surface scattering methods. Through grazing incidence X-ray diffraction and X-ray reflectivity studies, we reveal quantitative data about the lattice distances, molecular tilt angles, and mono/multilayer thickness and density profiles for central TFLL lipid classes under close to simulated physiological conditions. In addition, we discuss the correlation of the results to those obtained previously with the natural lipid composition of meibum.

Real or MADE-up: Investigating Mask-Associated Dry Eye (MADE) as an emerging syndrome.

Mask-Associated Dry Eye (MADE) has emerged as a consequence of widespread face mask usage during the Covid-19 pandemic. This review critically assesses the available evidence. A comprehensive search on PUBMED and EMBASE was conducted to identify studies on MADE, which were then categorized based on their design. A total of 26 studies were critically appraised, with the majority exhibiting poor study design quality. Investigating the impact of mask use on ocular surface irritation faced challenges due to global mask mandates, pandemic-related behavioural changes, and a lack of validated methods to measure the response to mask wear. Among the 15 studies, 12 reported a statistically significant reduction in TBUT associated with mask wear; however, the median decrease of 1.3 s was considered clinically insignificant. Results from Schirmer's test in 8 studies varied, with 5 studies reporting a decrease, contradicting the hypothesis of misdirected airflow. Out of 7 studies on corneal and conjunctival staining, 6 indicated a worsening associated with mask wear. Five studies investigating OSDI scores reported an increase following mask wear, but 3 studies repeated the survey too soon. Limited evidence suggests that masks may cause mild ocular surface irritation, but the quality and certainty of this evidence remain low. Methodological limitations were prevalent across the majority of studies, and the observed changes were minimal. Therefore, it is unlikely that significant ocular surface pathology will develop in the majority of mask wearers. Currently, there is insufficient data to support the establishment of a new syndrome.

Influential Signs of Dry Eye-Related Ocular Symptoms in Participants With Unstable Tear Film.

PURPOSE: The aim of this study was to investigate the factors influencing dry eye disease (DED)-related ocular symptoms in participants with short fluorescein tear break-up time (FTBUT). METHODS: This cross-sectional study included 82 participants with short FTBUT (<10 seconds). Examinations included Ocular Surface Disease Index (OSDI), FTBUT, average noninvasive tear break-up time (NIBUTave), lid wiper epitheliopathy, lipid layer thickness, blink rate, partial blink, tear meniscus height, and meibomian gland (MG) evaluation which included ratio of residual MG area (RMGA) and MG grade in tarsal plates. One-way analysis of variance was used to detect differences between symptomatic tear film instability group (FTBUT <5 s, OSDI ≥13), asymptomatic tear film instability group (FTBUT <5 s, OSDI <13), and control group (FTBUT ≥5 s, OSDI <13). A bivariate correlation, partial correlation, and multiple linear regression analyses were used to identify major factors. Only the right eye was included. RESULTS: Among the participants with FTBUT <5 seconds, symptomatic group showed less upper RMGA ( P < 0.001) and NIBUTave ( P = 0.010). OSDI was negatively associated with upper RMGA ( r = -0.450, P < 0.001) and NIBUTave ( r = -0.414, P = 0.001), and positively associated with upper MG grade ( r = 0.277, P = 0.027). Linear regression analysis showed that the upper RMGA significantly affected OSDI (B = -41.895, P = 0.001), while not significantly correlated with age, upper MG grade, and NIBUTave. CONCLUSIONS: The upper RMGA might be the main factor affecting DED-related discomfort in participants with unstable tear film, indicating an early ocular change in DED.

Review of clinical outcomes of a cationic emulsion tear substitute in patients with dry eye disease.

First-line options for the treatment of dry eye disease (DED) rely on artificial tears (ATs), among which cationic emulsion (CE)-based ATs have been developed in order to mimic the healthy tear film for an improved restoration of the ocular surface homeostasis. In this review, we describe the outcomes reported in several studies, assessing the mode of action, ocular tolerance and clinical performance of a CE-based AT. Pilot studies have revealed that CE-based ATs can increase the volume and stability of the tear film while limiting its evaporation rate. Larger studies have demonstrated that CE-based ATs play a significant role in the improvement of both objective and subjective DED parameters, including superior efficacy on DED symptoms compared to several other available AT formulation types. Concomitantly, CE-based ATs have been shown to help patients to prevent or recover from corneal defects associated with refractive surgery. These positive outcomes on ocular surface epithelia are likely due to the combination of unique rheological behaviour and intrinsic anti-inflammatory properties. Based on all clinical findings, CE-based ATs represent a valuable treatment option for patients with various etiologies of DED including evaporative forms and would deserve evaluation of benefits in other surgical intervention types triggering DED.

Cornea Classic: Stern, Beuerman, Fox, Gao, Mircheff, and Pflugfelder, "The Pathology of Dry Eye: The Interaction Between the Ocular Surface and Lacrimal Glands" (1998).

ABSTRACT: In one of the most frequently cited articles from Cornea , Stern et al's "The pathology of dry eye: the interaction between the ocular surface and lacrimal glands" (1998) revolutionized our current understanding of the pathophysiology of dry eye disease.

[Watery eyes: diagnostic and therapeutic considerations]. / Tranende ogen.

Tear complaints can arise from either an increased tear production or from a disturbed tear drainage. Increased tear production from the lacrimal gland is a neuroregulated response to a dried out or irritated ocular surface. Dryness often results from a reduced quality of the tear film, but can also be caused by eyelid malposition with increased globe exposure. Impaired tear drainage usually occurs when the lacrimal drainage system is blocked at the level of the ductus nasolacrimalis, the canaliculi or the lacrimal punctae. Anatomical knowledge of the lacrimal system is necessary to distinguish between the different causes. Using cases and illustrations, we provide insight into the diagnostic considerations for a patient with a watery eye.