CLINICAL RELEVANCE:Non-invasive break-up time (NIBUT) has become the measurement of choice to evaluate stability of the tear film. Tear film stability is essential in the diagnosis and follow-up of dry eye disease. BACKGROUND:Instruments used to measure NIBUT have different spacing of luminous mires, but the influence of this characteristic on the measurement of NIBUT is poorly understood. This study aimed at comparing the characteristics of five different instruments used to measure NIBUT and to determine if the mire spacing had an impact on the measured NIBUT. METHODS:Mire spacing of the instruments was assessed using a calibration sphere. Two raters then measured the NIBUT of 20 participants (20 eyes) with normal ocular surfaces three consecutive times with five different instruments (Oculus Placido Disk, Keeler Tearscope Plus with the Coarse and the Fine Grid, Medmont E300 Topographer and Oculus Keratograph 5M). A two-way repeated measure analysis of variance was performed to compare the NIBUT data and correlation values (intra-class and Spearman) were computed for intra-rater agreement and test-retest reliability. RESULTS:The Tearscope Plus with the Fine Grid was the instrument that presented the finest mire spacing. Two instruments, the Medmont E300 and the Keratograph gave shorter NIBUTs compared to the Tearscope Plus with the Fine Grid. All instruments had good inter-rater agreement. The Medmont E300 had a less good test-retest reliability for one of the raters. Bland-Altman plots were used to compare all the instruments with the one having the finest mire spacing. A positive proportional bias between the Tearscope Plus using the Fine Grid and the Coarse Grid was found. CONCLUSION:The topography-based instruments had shorter subjective NIBUT values in non-dry eye participants compared to the other instruments. Mire spacing is not the most definitive factor that impacts the NIBUT value.

This report provides an evidence-based review of current strategies to manage dry eye disease (DED). First-line management focuses on methods to replenish, conserve, and stimulate the tear film, with an emphasis on ocular supplements, which remain the cornerstone of DED treatment. Meibomian gland dysfunction, a primary contributor to DED, is typically treated with warm compresses and a wide variety of in-office treatments, including device-driven technologies to warm the eyelids, intense pulsed light therapy, low-level light therapy, and other new and emerging technologies. Lid hygiene treatments include lid wipes, anti-Demodex therapies, blepharoexfoliation, and topical antibiotics. DED caused by certain etiological drivers can benefit from anti-inflammatory therapies, including topical and oral corticosteroids, T-cell immunomodulatory drugs, and a wide variety of pharmacological agents, in addition to biologic tear substitutes such as autologous serum and platelet-rich plasma. Emerging therapies, such as neuromodulation via nasal neurostimulation and novel pharmacological treatments, offer potential future options. Advanced options, including amniotic membrane grafts and complex surgical methods, provide options for severe or refractory cases. Lifestyle modifications, including optimized blinking, dietary supplementation, and environmental adjustments, play a crucial role in long-term management. Patient education and adherence to treatment regimens remain essential for sustained symptom relief. The TFOS DEWS III prescribing algorithm provides an evidence-based framework to offer guidance to clinicians in selecting relevant interventions based on disease etiology that aim to provide targeted management of the relevant DED subtype(s) that an individual is experiencing.

PURPOSE:Periocular castor oil application shows possible benefits in managing Demodex blepharitis based on visibly reduced cylindrical dandruff at the base of the eyelashes, but the antidemodectic mechanism remains unclear. This research sought to establish Demodex mite susceptibility to castor oil directly in a controlled, ex vivo study. METHODS:Motile Demodex mites from epilated eyelashes with visible cylindrical dandruff were exposed to 5 µL aliquots of one of four castor oil or tea tree oil-based preparations, or remained unexposed (negative control). Adult Demodex mite motility was confirmed by high magnification microscopy every 5 min for up to 480 min post-exposure and survival time recorded when movement ceased. Tested oils were 100% cold-pressed castor oil, a proprietary castor oil preparation containing identical castor oil combined with manuka and kanuka oils, and 100% and 50% tea tree oil as positive controls. RESULTS:Survival time in the negative control group exceeded 480 min. All tested oils exhibited shortened mite survival time relative to the negative control (p < 0.05 in all cases). Survival times for 59 mites from 12 participants were plotted for the 5 experimental groups. Undiluted and proprietary castor oil preparations exhibited median (interquartile range; IQR) survival times of 235 (200-285) and 325 (240-405) minutes, respectively, with no significant difference between groups (p > 0.05). A single mite from each castor oil group survived beyond 480 min. Positive controls exhibited median (IQR) survival times of 5 (5-10) mins for 100% tea tree oil and 20 (15-25) mins, for 50% tea tree oil. CONCLUSIONS:Castor oil alone, or in proprietary form supplemented with manuka and kanuka oils, reduced Demodex survival over an 8-hour period. Outcomes suggest extended duration exposure to castor oil, such as in overnight application, has demodecidal activity that could contribute to Demodex blepharitis management.

CLINICAL RELEVANCE:The multifactorial aspect of dry eye disease remains challenging. Demodex folliculorum, a common ectoparasite on human eyelashes, may impact eye conditions such as blepharitis which can be a contributor to dry eye disease. Exploring risk factors for Demodex helps to raise awareness for early detection potentially improving ocular health. BACKGROUND:Demodex folliculorum found on eyelashes can cause blepharitis. Its gelatinous debris at the base of the lashes, termed cylindrical dandruff is often associated with ocular itching. This study examined the prevalence of Demodex in a University population and assessed its relationship to symptoms of dry eye and itching. METHODS:Visual acuity, dry eye questionnaire (OSDI), non-invasive break up time (NIBUT), meibography, and slit-lamp examination were measured. When cylindrical dandruff was observed, lateral tension was exerted on two eyelashes to identify Demodex tails. Mann-Whitney tests were applied for comparisons, logistic regressions were applied to determine relationships, and chi-square, Fisher's exact test and Spearman correlation tests determined associations. RESULTS:Of the 101 participants (mean age: 28 ± 12, range: 19-68 years, 90 females), 20% had dry eye (OSDI score ≥ 13 and NIBUT < 10 sec). Demodex tails/lash were significantly more prevalent in the upper (44%) compared with the lower eyelids (19%). Anterior blepharitis and cylindrical dandruff were significantly correlated with Demodex. Ocular itching (prevalence: 39%) was significantly associated with presence of Demodex only for the upper eyelids (p = 0.02). UODS was positively correlated (p < 0.001) with Demodex, cylindrical dandruff and anterior blepharitis. CONCLUSIONS:There was a relatively high prevalence of Demodex among a university population. The prevalence of Demodex was not significantly different in those diagnosed with dry eye. Cylindrical dandruff and anterior blepharitis were significantly associated with the presence of Demodex, while itching was associated with presence of Demodex only for the upper eyelids. The UODS can be a valuable tool to add in future Demodex studies.

PURPOSE:The central lower TMH is used as a clinical measure of tear volume in the assessment of contact lens candidates and patients with dry eyes. Ethnic differences in eyelid morphology may influence the measurement of the TMH. Furthermore, with the advent of larger contact lenses, such as scleral lenses, it would be of clinical value to assess the TMH centrally and peripherally. The purpose of this study was to evaluate and compare the TMH at different positions along the palpebral margin between Caucasian and Asian eyes. METHODS:This prospective study evaluated the lower TMH in five positions (central, temporal and nasal limbus and temporal and nasal periphery) of the right eye using the Keratograph 5M (Oculus) instrument in Caucasian and Asian participants between 10 am and 12 pm . The TMH at each position was taken three times and averaged and analyzed using a 5 × 2 repeated-measures analysis of variance. RESULTS:Central TMH did not differ significantly ( F = 0.02, p=0.88) in Caucasians (n = 20, aged 24.45 [2.30] years, TMH 0.320 [0.052] mm) and Asians (n = 20, aged 22.25 [3.43] years, TMH 0.325 [0.048] mm). A difference was noted with respect to TMH positions along the lid margin ( F = 64.17, p<0.001), independent of ethnicity ( F = 2.15, p=0.15). A post hoc analysis revealed a significantly higher TMH temporally when compared with centrally or nasally (p<0.001). CONCLUSIONS:This study demonstrated the similarity of the central TMH and the differences in the peripheral TMH within Caucasian and Asian eyes. This may be clinically relevant when using the Tear Film & Ocular Surface Society Dry Eye Workshop II diagnostic algorithm for dry eyes and when fitting scleral contact lenses. Future studies need to consider that ethnic differences may exist for certain tests in order to personalize the care and management of each patient.

Clinical relevance: Ocular lubricants are the mainstay of dry eye management and are available in a variety of formulations and bottle designs. The squeezability of ocular lubricant bottles may influence administration and compliance. Background A key component for managing dry eye disease is the use of ocular lubricants. The different bottle types, each with their unique material strength and dispensing mechanism, may be challenging for patients with limited hand and pinch strength. The aim of this study was to evaluate the force required to expulse a drop from different eye drop containers used in the management of dry eye disease. Methods: The force, in newtons (N), required to expulse a drop from different eye drops was evaluated five times using a force gauge, and divided by bottle type, i.e. tubes, unidose, multidose with preservatives, and multidose preservative free (MDPF) bottles. Results: Sixty (n = 60) bottles were examined with 57 eye lubricants and 3 dry eye medications (cyclosporine (0.5% and 0.9%), and lifitegrast). The average force varied depending on the bottle type (tubes 4.28 +/- 1.29 N; unidose 14.24 +/- 4.83 N; multidose 16.62 +/- 5.21 N; MDPF 26.68 +/- 8.32 N, p < 0.001). Post-hoc test revealed that MDPF bottles required more force than all other bottle types (p < 0.001), and among those, the ophthalmic squeeze dispenser bottle required significantly more force (p < 0.001). Lifitegrast required more force (17.38 +/- 2.13 N) than cyclosporine 0.5% (9.16 +/- 0.80 N, p < 0.024) and cyclosporine 0.9% (5.68 +/- 0.40 N, p < 0.001), but was not significantly different from unidose ocular lubricants (p > 0.05). Conclusion: The squeezability of bottles used in dry eye disease management varies with bottle type. Hand and pinch strength should be considered when choosing products for dry eye disease management, as the squeezability of an ophthalmic drop can influence its administration and compliance.

OBJECTIVE:Demodex folliculorum blepharitis is typically confirmed with lash epilation and microscopic identification of mites. However, mite counts may vary with the epilation technique. As there is no gold standard to epilating lashes for the purposes of mite counts, the aim of this study was to compare three epilation techniques. METHOD:A prospective randomized double-blind study compared three epilation techniques on lashes with cylindrical dandruff. Techniques included (A) direct pulling of the lash; (B) rotating the lash before epilation; and (C) sliding the cylindrical dandruff away, lash rotation, and epilation. Mean mite counts were analyzed using a repeated-measures analysis of variance. RESULTS:Forty (n=40) participants (20 M: 20 F, mean age of 62.3±17.1 years) revealed similar mite counts between right (1.43±1.74) and left (1.35±1.59) eyes ( P =0.63). A significant difference ( P =0.03) in mite count was noted (technique A: 1.05 ± 1.60; technique B 1.76 ± 1.80; and technique C 1.36 ± 1.54) with technique B yielding the highest mite count ( P =0.04). CONCLUSION:Demodex mite count is a key parameter in establishing infestation or to determine treatment efficacy. This study revealed that rotating the lash before epilation yielded the highest mite count. Future studies should report the epilation technique used to allow for study comparisons.

Blepharitis is defined as inflammation of the eyelids, classified according to anatomical location: anterior (eyelid skin, base of the lashes including the eyelash follicle) or posterior (meibomian glands) blepharitis. Although blepharitis is one of the most common ocular disorders, epidemiological data on the condition is lacking, making prevalence difficult to assess. A 2009 survey of eyecare practitioners reported observing blepharitis in 37%–47% of patients in their clinical practice. This observation may vary depending on the age, sex, and types of patients (i.e., dry eye) in the practice. Younger females are found to have more acute short-term presentation of blepharitis, whereas older, more fair-skinned females present with chronic blepharitis often concurrent with rosacea. Large population‑based studies, using a standardized definition and diagnostic technique, are needed to properly assess the prevalence and incidence of blepharitis and to allow for study comparisons among various age groups. The ocular surface, including the lid margin, has a natural flora or microbiome, which is imperative in maintaining the health and defence mechanism of the ocular surface. This can be affected by age, gender, inflammation, disease, medication, cosmetics, and treatment (systemic or topical). An overgrowth of microbes or an imbalance of the natural flora may result in an inflammatory response, leading to blepharitis, conjunctivitis, keratitis, or a combination of these.

The word “elective” refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.

SIGNIFICANCE:The advancing age of the population will require increased access to eye care services to manage eye diseases and vision correction. Optometric education requires a sound financial plan to manage student debt. This study evaluates the financial inequalities of optometric programs in Canada and how this may impact the provision of eye care professionals. PURPOSE:The objective of this study was to compare the financial inequities in optometric education in Canada from the 2020 graduating class. METHODS:A cross-sectional study assessed monetary variables related to the study of optometry in Canada, including academic and personal expenses, and overall debt and expenses related to the COVID-19 lockdown for the 2020 graduating class. RESULTS:A total of 108 optometry students from the 2020 graduating classes of the University of Montreal and the University of Waterloo responded, with 68 (female/male respondents, 53:15; mean [standard deviation] age, 25.66 [2.01] years) completing the study. Waterloo students spent more years in university ( P < .001), had higher academic fees ( P < .001), spent more on traveling to their family residence ( P = .007), and received more provincial ( P = .002) and federal ( P < .001) loans than Montreal students. Overall debt before optometry was similar among students but differed ( P < .001) at the end of their program, with Waterloo students having a higher debt burden. CONCLUSIONS:There is a financial inequity in optometric education in Canada depending on the chosen program. Cumulative optometry student debt for the 2020 graduating class in Canada ranges from Can $0 to $189,000 with an average of Can $65,800 and a median of Can $50,000. The results of this study can assist financial and government agencies, and future optometry students to better understand the financial burdens and establish a financial plan to study optometry in Canada, to respond to the growing eye care needs of the public.

PURPOSE:To evaluate the short-term tolerability of five commercially available anti-demodectic eyelid cleansers; OCuSOFT Oust Demodex (OD), I-MED I-Lid'n Lash Plus (ILL+), Labtician BlephaDex (BD), Chrissanthe Eye Cleanse (EC), and Théa Blephademodex (BDdx). METHODS:Thirty healthy non-contact lens wearers (18 female; mean ± SD age, 33 ± 12 years) were enrolled in a prospective randomised crossover study. On separate visits, spaced at least 48 h apart, participants were randomised to receive topical application of one of five eyelid cleansers or saline. Participants rated subjective ocular discomfort during the 10-minute post-application period. Visual acuity, non-invasive tear film stability, conjunctival hyperaemia, and ocular surface staining were assessed at baseline and 10 min. RESULTS:No inter-group differences in ocular parameters were noted at baseline (all p > 0.05). Ocular discomfort scores significantly exceeded baseline scores for 60 s following BD application, 120 s with OD, 135 s with BDdx, 150 s with ILL+, and 195 s with EC (all p < 0.05). Deterioration in non-invasive tear film stability, limbal conjunctival hyperaemia, as well as corneal, conjunctival, and lid margin staining was detected following EC application (all p < 0.05), and increased bulbar conjunctival hyperaemia was observed following both EC and ILL+ treatment (both p < 0.05). CONCLUSIONS:Study outcomes highlight varying tolerability profiles with different anti-demodectic lid cleanser preparations, and the potential to induce tear film instability, conjunctival hyperaemia and ocular surface staining on application. Awareness of possible adverse effects arising from topical application of commercial anti-demodectic lid cleanser formulations may help clinicians set realistic patient expectations and encourage better compliance in their use of lid hygiene therapies.

Demodex is the most common parasite living on humans and yet little is understood about its pathogenicity with respect to the ocular surface. An increasing interest in Demodex over the past 20-years has increased our understanding of this mite and its pathogenetic role. This article begins with a review of the anatomy, life cycle, mode of transmission and advances in genetics that can distinguish between Demodex folliculorum and Demodex brevis, the only two Demodex species in humans. Additionally, a review of diagnostic procedures and existing and emerging ocular and systemic management options are presented. Despite the increasing interest in Demodex in the literature, there remains numerous obstacles for future studies, hence a section of this review is dedicated to the identification and proposal for future considerations. The lack of uniformity with respect to terminology, diagnostic technique and management approach for Demodex remain as obstacles for future study comparisons. This review summarised the current knowledge on Demodex and hopes to offer some recommendations for future directions in the study of Demodex in humans.

SIGNIFICANCE The prevalence of dry eye disease and low vision increases with age; they share risk factors and can be the result of underlying common causes. They are generally studied separately; however, combining these perspectives is relevant for research on assistive technology given that sustained focus affects the tear film because of decreased blinking rates. PURPOSE The objective of this study was to elucidate to which extent dry eye disease risk factors, signs, and symptoms are assessed in low vision patients who receive an eye examination as part of their vision rehabilitation services. METHODS Using a retrospective chart review, dry eye disease risk factors, signs, or symptoms were extracted from 201 randomly selected files that contained an eye examination in the past 5 years from two vision rehabilitation centers. RESULTS Demographic variables of charts from the two sites did not differ (mean visual acuity, 0.85 logMAR [standard deviation, 0.53; range, 0 to 2.3]; mean age, 71.2 years [standard deviation, 19 years; range, 24 to 101 years]). Fifty charts (25%) mentioned at least one dry eye disease symptom. Sixty-one charts (30.3%) reported systemic medications that can exacerbate dry eye disease, whereas 99 (49.2%) contained at least one systemic disease thought to contribute to dry eye disease symptoms; 145 (72.1%) mentioned at least one type of ocular surgery. Artificial tears were documented in 74 charts (36.8%). Few specific dry eye tests were performed, with the exception of corneal integrity assessment reported in 18 charts (8.95%). CONCLUSIONS Low vision patients have multiple risk factors for dry eye disease; however, dry eye disease tests were not frequently performed in comprehensive low vision eye examinations in this sample. More efforts should be made to assess dry eye disease to enhance comfort and functional vision, especially with the increasing demands of digital devices as visual aids.

Demodex is the most common parasite living on humans and yet little is understood about its pathogenicity with respect to the ocular surface. An increasing interest in Demodex over the past 20 years has increased our understanding of this mite and its pathogenetic role. This article begins with a review of the anatomy, life cycle, mode of transmission and advances in genetics that can distinguish betweenDemodex folliculorumandDemodex brevis, the only two Demodex species in humans. Additionally, a review of diagnostic procedures and existing and emerging ocular and systemic management options are presented. Despite the increasing interest in Demodex in the literature, there remains numerous obstacles for future studies, hence a section of this review is dedicated to the identification and proposal for future considerations. The lack of uniformity with respect to terminology, diagnostic technique and management approach for Demodex remain as obstacles for future study comparisons. This review summarised the current knowledge on Demodex and hopes to offer some recommendations for future directions in the study of Demodex in humans.

SIGNIFICANCE Dry eye disease (DED) imposes a substantial burden on patients, which can lead to significant economic consequences for society. We provide insights into the DED patient population and DED diagnostic/management practices in Canada, which to date have been inadequately addressed in the literature. PURPOSE The purpose of this study was to describe DED patient demographic/clinical characteristics alongside DED diagnosis/management in university-based optometry clinics in Canada. METHODS This was a retrospective chart review of nonconcurrent non-Sjögren patients with DED at two university-based optometry clinics in Montreal and Waterloo. Waterloo charts with a diagnosis of DED and all charts from the Montreal dry eye clinic were considered for inclusion. RESULTS Overall, 200 charts were reviewed. Most patients were female (Montreal, 76%; Waterloo, 72%), and the mean age was 57.2 ± 14.9 years at Montreal and 52.6 ± 20.1 years at Waterloo. Patients commonly reported multiple health conditions (e.g., allergies [Montreal, 44%; Waterloo, 36%]), and high use of systemic nonocular medications was observed (Montreal, 76%; Waterloo, 62%). Clinical signs and symptoms of DED were recorded more often in Montreal patients than in Waterloo patients (e.g., dryness symptoms, 100 vs. 72%; tear breakup time, 100 vs. 60%). Warm compresses (Montreal, 63%; Waterloo, 83%) and artificial tears (Montreal, 94%; Waterloo, 96%) were the most frequently recommended nonmedical treatment and ocular lubricant, respectively. Topical steroids were the most frequently prescribed medications (Montreal, 22%; Waterloo, 21%), with typically three to four different interventions recommended per patient at each clinic. No relationship was found between symptoms and clinical signs or recommended interventions. CONCLUSIONS This retrospective chart review provided the demographics, clinical characteristics, diagnosis, and management options for DED patients in Canadian university-based optometry clinics. The more comprehensive assessments conducted at Montreal may be beneficial to better monitor the progression of DED and to determine treatment effects over time.

Purpose: To evaluate facial Demodex densities in participants with varying severities of blepharitis secondary to Demodex folliculorum.

Open almost any ophthalmic journal and you will likely find one or more articles discussing some aspect of dry eye. The literature on dry eye is vast, growing exponentially, and confusing at the same time. In order to bring order and good evidence-based science to this almost limitless field of data, the Tear Film and Ocular Surface Society (TFOS) Dry Eye Workshop (DEWS II) in 2017 published the most comprehensive meta-analysis of this expansive literature, updating the prior TFOS DEWS report from 2007.

Purpose: Evaluating tear volume, as measured by the inferior central tear meniscus height (TMH), is a valuable clinical measure in the assessment of tear deficient dry eye (DE). A previous study (Bitton, Wittich 2014) found that an inferior gaze position increased the Schirmer score over that of superior gaze. Due to the invasive nature of the Schirmer strip coupled with the enhanced resolution of imaging techniques such as optical coherence tomography (OCT), it would be of clinical value to reassess if gaze position has an influence on the tear meniscus using an anterior segment OCT.

PURPOSE:To evaluate facial Demodex densities in participants with varying severities of blepharitis secondary to Demodex folliculorum assessed by the highest number of cylindrical dandruff on one lid. METHODS:This double masked cross-sectional study included 58 participants [19 control, 21 mild/moderate and 18 severe Demodex blepharitis] who underwent a standardized skin-surface biopsy and a lash epilation for each lid to obtain the forehead Demodex densities and the overall lash mite count, respectively. Also, facial photographs were taken to evaluate facial erythema and dermatological conditions. The Ocular Surface Disease Index [OSDI], non-invasive break-up time [NIBUT], tear meniscus height [TMH], bulbar conjunctival redness as well as additional questions on watery eyes, ocular itching and itching along the lids were assessed. RESULTS:Both mild/moderate and severe Demodex blepharitis groups were over the cut-off value [≥ 5 mites/cm2] that confirms a facial demodicosis (mild/moderate: 5 ± 1; severe: 6 ± 1) while the control group was below it (2 ± 1). Thereby, group comparisons showed that an increased severity of Demodex blepharitis was associated with higher forehead mite densities (p = 0.002) and increased lash mite count (p < 0.001). The degree of facial erythema was also positively correlated with forehead mite densities (rs = 0.31, p = 0.02). When compared to the controls, the mild/moderate group had more watery eyes (X2 = 6.54, p = 0.02), a lower TMH (U = 100.5, p = 0.006) and the severe group had more itching along the lids (X2 = 4.94, p = 0.04). The other ocular signs and symptoms [NIBUT, bulbar conjunctival redness, OSDI] were not affected by the severity of Demodex blepharitis (p > 0.05). CONCLUSION:Palpebral and facial Demodex infestation can co-exist, as the presence of blepharitis secondary to Demodex is associated with increased facial mite densities.