Inflammatory status predicts contact lens discomfort under adverse environmental conditions

PurposeTo characterize and predict the clinical and tear molecular response of contact lens (CL) wearers exposed to a controlled adverse desiccating environment (CADE).MethodsObjective and subjective variables and tear cytokine levels were evaluated of monthly silicone hydrogel CL wearers pre- and post-90 min of CADE exposure. Unsupervised hierarchical agglomerative clustering based on relative change from baseline values was used to identify response profiles (clusters). A multiple logistic regression model was used to identify cluster membership predictors.ResultsForty-seven CL wearers were divided into 3 clusters having similar age (mean: 27.7 ± 7.7 years) and sex distribution. All of them showed a significant (p ≤ 0.05) increase in limbal hyperemia and staining after CADE exposure. Additionally, Cluster-1 (n = 22, 46.8%) membership was characterized by a significant (p ≤ 0.05) higher worsening of corneal and limbal staining, increased CL wear symptoms, and reduced epidermal-growth-factor and increased interleukin (IL)-4 and IL-6 tear levels. Cluster-2 (n = 22, 46.8%) showed no changes (p > 0.05) in symptoms after CADE; however, their IL-12p70, monocyte-chemoattractant-protein-1 and regulated-on-activation, normal-T-cell-expressed-and-secreted (RANTES) post-exposure tear levels significantly (p ≤ 0.05) increased. Finally, Cluster-3 (n = 3, 6.4%) mainly showed significant higher blink rate (78.1 ± 21.7) during CADE. Corneal staining and tear IL-12p70 levels were identified as Cluster-1 membership predictors.ConclusionsMost of silicone hydrogel CL wearers exposed to CADE showed a worsening of the ocular surface integrity and an upregulated tear inflammatory status. However, only half of them reported worsening of CL wear symptoms. These CL wearers were detected based on corneal integrity and tear inflammatory status. These findings can help reduce CL wear discontinuation and drop out.     

Tear ferning in contact lens wearers

Tear ferning (TF) has shown good sensitivity and specificity in the diagnosis of dry eye, but is a relatively uncommon test, especially in contact lens wearers. The aim of this study was to investigate the relationship between TF, ocular comfort and tear film stability amongst contact lens (CL) wearers and non-contact lens (NCL) wearers. Subjects (36 NCL, 24 CL; mean age 23.2 ± 4.8 years) underwent assessment of non-invasive tear break up time (NIBUT), fluorescein tear break up time (FBUT) and completed the Ocular Comfort Index (OCI) questionnaire. Non-stimulated tears were collected from the inferior tear meniscus with a glass capillary. Samples of 1.5 μL were air dried, observed by light microscopy and the TF pattern quantified according to Rolando's grading scale. Significantly higher grades of TF pattern and discomfort (higher OCI scores) were observed in CL wearers compared to NCL wearers (Mann–Whitney U -test; p  < 0.005 and p  < 0.05 respectively). Differences in tear film stability were not significant between groups. Even when asymptomatic (low OCI scores) CL and NCL subjects were compared, TF remained significantly different ( p  < 0.005). In both CL and NCL subjects, TF displayed poor correlation with tear film stability tests and OCI scores. Higher TF grades in CL wearers, even if asymptomatic, indicate an unfavourable ratio of salt to macromolecule concentration within the tear film of such subjects. The lack of significant difference in TF between symptomatic CL and NCL wearers could suggest similar aetiology (tear film hyperosmolarity) in each cohort. The TF technique demonstrates limited sensitivity and specificity for the prediction of ocular surface comfort in both CL and NCL wearers.     

Ocular surface assessment in soft contact lens wearers; the contribution of tear osmolarity among other tests

Purpose:  To determine whether tear osmolarity contributes to the assessment of the ocular surface in soft contact lens (CL) wearers. Methods:  Prospective, case–control series in 44 CL wearers (28 tolerant and 16 intolerant) and 34 healthy subjects. Every patient underwent a thorough ophthalmic examination with a tear osmolarity test (TearLab System), conjunctival impression cytology and meibomian lipid sampling. Symptoms, break‐up time (BUT), tear osmolarity, conjunctival expression of HLA‐DR and meibomian fatty acid composition were evaluated. Results:  Tear osmolarity did not differ between controls and CL wearers (p = 0.23). Flow cytometry results expressed in antibody‐binding capacity (ABC) units and percentage of positive cells revealed a significant difference between the intolerant CL wearer group and the control group (p < 0.0001). Comparisons between tolerant and intolerant CL wearers showed only a significant difference for mean fluorescence levels expressed in ABC units (p < 0.0001). The BUT was significantly shorter in intolerant and tolerant CL wearers subjects than in healthy subjects (p < 0.0001), whereas there was no significant difference in meibomian fatty acid composition (p = 0.99) between the two groups. Conclusion:  Contact lens wear is responsible for ocular surface alterations whose patterns are very similar to those reported in early dry‐eye syndrome. However, tear osmolarity was not modified in these selected CL wearers. The yield of tear osmolarity with TearLab? in assessing ocular surface disorders in CL wearers deserves further investigation.     

Role of diurnal variation of corneal sensory processing in contact lens discomfort

PurposeTo examine the diurnal variation of corneal threshold and suprathreshold sensory processing, symptoms, and tear secretion in symptomatic and asymptomatic contact lens (CL) wearers and controls.Methods26 symptomatic and 25 asymptomatic CL wearers and 15 asymptomatic non-CL wearing controls participated. Cooling thresholds, symptoms and tear meniscus height (TMH) were measured on each of 3 measurement days (random order) on the following schedules; Day-1 within 1 h of awakening (Baseline) and 3, 6 and 9 h later, Day-2 baseline and 9 h later (CLs worn in CL group) and Day-3 baseline and 9 h later. Magnitudes estimates for threshold-scaled suprathreshold stimuli were also estimated on Day-3. Data were analyzed using mixed models and repeated measures ANOVA.ResultsCooling thresholds for the symptomatic group were lower and decreased over Day-1 (p < 0.008) and after 8 h of CL wear on Day-2 (p < 0.001) and were paralleled by increased symptoms (all p < 0.001), whereas minimal variations were found in the asymptomatic and control groups. Magnitude estimates for suprathreshold stimuli were higher (p ≤ 0.002) in the symptomatic group but did not differ significantly over the day. TMH varied little over time and was lower in the symptomatic group, but the difference was not statistically significant.ConclusionCorneal sensitivity and symptoms, but not TMH, increased diurnally irrespective of CL wear in symptomatic CL wearers. These results reveal the essential role of neurosensory abnormalities in CL discomfort and suggest involvement of a central mechanism in the diurnally increased symptoms of these patients.     

Basal and Reflex Human Tear Analysis: I. Physical Measurements: Osmolarity,Basal Volumes,and Reflex Flow Rate

Minimally stimulated, retained “basal” tears and stimulated reflex tears were collected from normal controls, keratoconjunctivitis sicca (KCS) patients, and contact lens (CL) wearers. Basal tear samples were collected on small filter paper strips (Periopaper®) over a five-second period, and volume was measured by means of an electronic device (Periotron®). Collected basal tear volumes for KCS patients (0.84 ± 0.42 μl) were significantly lower (P <; 0.01) than normal controls (1.18 ± 0.36) and CL wearers (1.24 ± 0.27). Reflex tear flow rates were measured over a five-minute period on Schirmer strips. Volume was calculated by comparison of wet length with known volumes of 1% egg white lysozyme solution. The reflex tear flow rates in KCS patients (3.29 ± 3.57 μl/minute) were significantly lower than normal controls (5.71 ± 5.86) and CL wearers (6.96 ± 6.07). The elevation in CL wearers was not statistically significant when compared to normals. KCS patients are deficient in both basal and reflex tears compared to normals but have a more significant deficiency of basal tears. Female normals and CL wearers over 40 years of age have a higher tear osmolarity than those under 41 years of age. Female KCS patients over 40 years of age have a tear osmolarity that is not significantly different from female KCS patients under 41 years of age.     

Peripapillary retinal nerve fibre layer thickness measurement with SD-OCT in normal and glaucomatous eyes:distribution and correlation with age

AIM:To determine peripapillary retinal fiber layer thickness (RNFL) measured with spectral domain optical coherence tomography (SD-OCT) in normal and glaucomatous eyes in a large sample of exclusively white population and compare results with other similarly constructed studies.METHODS:Average, maximum, minimum and per quadrant RNFL thickness were measured in normal and glaucomatous Greek patients with a scanning laser ophthalmoscope (SLO)/SD-OCT device. The effect of age in normal RNFL thickness was also determined.RESULTS: A total of 278 normal (278 patients) and 67 glaucomatous (67 patients) eyes were included in the study. Average RNFL thickness was 114.8±13.3μm in normal and 92.1±18.5μm in glaucomatous eyes (P<0.001). In normal discs, superior quadrant was the thickest, followed by the inferior, nasal and temporal. Decline of normal RNFL thickness with age was statistically significant for average RNFL thickness (1.92μm per decade of life) and for the superior and inferior quadrants of the disc.CONCLUSION:SD-OCT peripapillary RNFL measurements can be used to distinguish between normal and glaucomatous eyes and establish normative databases, since normal disc measurements differ between different ethnic groups and between different SD-OCT devices.     

A link between tear breakup and symptoms of ocular irritation

Purpose

We used the presence or absence of a soft contact lens (CL) as a barrier to test the hypothesis that tear breakup (TBU) presents a direct noxious stimulus to the ocular surface.

Exploring topical anti-glaucoma medication effects on the ocular surface in the context of the current understanding of dry eye

Purpose

To assess tear film parameters, ocular surface characteristics, and dry eye symptomology in patients receiving topical anti-glaucoma medications.

Comparison of the effects of first and second generation silicone hydrogel contact lens wear on tear film osmolarity Running title:Tear film osmolarity and silicone hydrogel contact lens wear

AIM: To evaluate the outcomes of pars plana vitrectomy (PPV) without the use of an ocular tamponade in patients having tractional retinal detachment (TRD) secondary to proliferative diabetic retinopathy (PDR).METHODS: It was an interventional study conducted at the Department of Ophthalmology, B.V. Hospital, Bahawalpur, Pakistan, from July 2011 to July 2012. A total of 75 patients (84 eyes) having TRD secondary to PDR were treated by PPV without using an ocular tamponade. All patients included in the study had a tractional retinal detachment secondary to proliferative diabetic retinopathy but didn’t have or develop retinal breaks before or during the study period. The surgical procedure included a PPV combined with the removal of the tractional retinal membranes and the application of endolaser photocoagulation to the retina. The mean follow-up period was 12 months.RESULTS:Successful retinal reattachement was observed in 78 of the operated eyes (92.8%). In these patients, the retina remained attached till the end of the one year follow-up period. Improvement in best corrected visual acuity (BCVA) was seen in 63 eyes (75%). The visual acuity remained unchanged in 9 eyes (10.7%). Mean improvement in BCVA was 2.00+1.24 at baseline to 1.24+1.22 (P<0.05) at the end of the follow-up period.CONCLUSION: In the absence of the retinal breaks, a TRD secondary to PDR can be successfully treated by pars plana vitrectomy without the use of an ocular tamponade.     

角膜接触镜相关性干眼与睑板腺形态变化的关系

目的:探讨软性角膜接触镜(CL)长期配戴者睑板腺形态改变与干眼观察指标的关系。方法:采用横断面研究方法,连续纳入2014年5月至2015年6月就诊于天津医科大学眼科医院拟行屈光性手术的患者157例314眼,其中长期配戴软性CL者91例182眼作为CL组,未配戴CL者66例132眼作为对照组。收集并比较2个组患者眼表疾病...     

Morphological characteristics of Meibomian Glands and their Influence on Dry Eye disease in contact lens wearers

PurposeMeibomian glands (MG) are now easily imaged via clinical meibography machines. The purpose of this work was to explore the utility of the known MG morphology metrics for predicting dry eye disease (DED) in contact lens (CL) wearers.MethodsSuccessful and previous CL wearers were recruited. DED was diagnosed if the participant's worst eye had a reduced tear meniscus height (TMH) of <0.2 mm or non-invasive tear break-up time (NITBUT) of <10 s and a Standardized Patient Evaluation of Eye Dryness (SPEED) score >5.0. Meibography was performed and images were subjectively graded by two examiners for the following MG characteristics: distorted, tortuous, hooked, abnormal gap, overlapping, fluffy areas, tadpoling, thinned, thickened, ghost, no extension to lid margin, shortened and dropout (atrophy). DED diagnostic ability of each metric was determined with receiver operating characteristic (ROC) analysis.ResultsA total of 112 participants were recruited, with 18.8% having DED and 60.7% being female. The only MG morphology metrics that were marginally predictive of DED were thickened upper eyelid MGs (p = 0.046), thickened mean upper plus lower eyelid MGs (p = 0.007), and atrophy of upper eyelid MGs (p = 0.043); however, none of these metrics reached a meaningful area under the curve in ROC analysis (all <0.70).ConclusionWhile abnormal MG morphology is likely suggestive of DED in CL wearers, none of the MG morphology metrics evaluated alone in this study had clinically meaningful predictive value for detecting DED in this group of current and previous CL wearers.     

Comparison of the impact of nesofilcon A hydrogel contact lens on the ocular surface and the comfort of presbyopic and non-presbyopic wearers

AIM: To assess and compare the impact of a daily disposable contact lens (CL) with high water content on the ocular surface and comfort of the presbyopic and non-presbyopic population after one day of use. METHODS: Totally 20 presbyopes and 30 non-presbyopes non-contact wearers were fitted with nesofilcon A CLs. CL thickness was measured to assess material stability during daily wear, and ocular surface parameters were also assessed. Optical quality was analyzed for all cases. In addition, CL comfort was rated. RESULTS: No significant differences were found in CL thickness, tear film osmolarity, average tear break-up time, bulbar redness, central corneal thickness, corneal volume, root-mean-square of higher-order aberrations (RMS of HOAs) and vertical and horizontal coma, either as a function of the group or time of use. A significant decrease in tear meniscus height and first break-up of the tear film was found in the presbyopic group (P=0.038; P=0.007 respectively). A decrease in spherical aberration coefficient was found after CL insertion (P=0.031 monofocal CL; P=0.023 low addition multifocal CL; P=0.016 high addition multifocal CL). Multifocal CL were thicker than monofocal CL (P=0.045). Comparison between groups showed more discomfort in presbyopes than non-presbyopes (P=0.003). CONCLUSION: This study evidence that the behavior of the daily disposable CL with high water content seems to be stable during the day of use. Ocular parameters measured during wear show that CL behavior is the same for presbyopes and non-presbyopes, being more uncomfortable for presbyopes.     

Basal and Reflex Human Tear Analysis: II. Chemical Analysis: Lactoferrin and Lysozyme

Unstimulated basal tears and stimulated tears were collected from normal controls, keratoconjunctivitis sicca (KCS) patients, and contact lens (CL) wearers. Basal tear volume (Periopaper®) and reflex tear volume (Schirmer Strip®) were measured and tears eluted from their respective strip with a TMED-acetic acid buffer. Lactoferrin and lysozyme concentrations were measured in the eluates. Concentration of lysozyme in basal tears was: 65 ± 43 mg% in normals; 44 ± 26 mg% in KCS, and 81 ± 50 mg% in CL wearers. Concentration of lysozyme in reflex tears was: 160 ± 73 mg% in normals, 74 ± 41 mg% in KCS, and 186 ± 83 mg% in CL wearers. Concentration of lactoferrin in basal tears was 137 ± 102 mg% in normals, 154 ± 82 mg% in KCS, and 157 ± 80 mg% in CL wearers. Concentrations of lactoferrin in reflex tears was: 327 ± 187 mg% in normals; 171 ± 69 mg% in KCS, and 302 ± 160 mg% in CL wearers. The lactoferrin concentration in all tear samples was consistently higher (1.6–3.5 times) than lysozyme. In basal tears, lactoferrin concentrations were not significantly different in the three groups. In reflex tears, however, lactoferrin was significantly lower in KCS than normal or CL wearers. The concentration of lysozyme in both basal and reflex tears was significantly lower in the KCS when compared to normal or CL wearers. Lysozyme and lactoferrin concentrations in both basal and reflex tears were similar in CL wearers and normal controls. The sampling and elution of basal and reflex tears as described appears to be a feasible technique for analysis of lysozyme-and lactoferrin concentrations by the electroimmunodiffusion technique and has potential diagnostic value.     

【In Press】The association between demodex infestation and ocular surface manifestations in meibomian gland dysfunction

AIM: To investigate the association between ocular demodex folliculorum infestation and ocular surface manifestations in meibomian gland dysfunction (MGD). METHODS: Eight-six subjects with MGD were enrolled. All enrolled subjects were tested in the following sequence: ocular surface disease index (OSDI), slit lamp biomicroscope examination, corneal surface regularity index (SRI) and asymmetry index (SAI), tear fluid collection, fluorescein tear film break-up time (F-BUT), corneal fluorescein staining (CFS), modified Schirmer I test with anesthetic (SIT) and finally demodex folliculorum counting. Tear matrix metalloprotein (MMP)-9 activity was assessed with a MMP-9 activity assay kit. RESULTS: Ocular demodex mite was found in 40 of 86 patients with MGD. The ocular demodex-positive group showed significantly increased scores of OSDI (25.96±13.74 vs 18.07±11.55, p=0.01), lid margin abnormality (2.38±0.87 vs 1.98±0.91, p=0.04) and CFS (1.28±2.00 vs 0.94±1.36, p=0.01) compared to the ocular demodex-free group. The tear MMP-9 activity was higher in the ocular demodex-positive group (102.9±32.4 ng/ml) than the ocular demodex-free group (46.2±19.2 ng/ml, p=0.03). There was no significant difference in meibum quality and expressibility, SRI, SAI, F-BUT and SIT between the two groups (p>0.05 for each). No significant correlation was noted between the number of demodex and ocular surface parameters in demodex-positive MGD (p>0.05 for each). CONCLUSION: Ocular demodex folliculorum infestation may be associated with ocular discomfort and ocular surface damage in MGD.     

In vitro and in vivo effects of a lubricant in a contact lens solution

PURPOSE: Physical properties and tear film function were investigated for a multipurpose contact lens solution containing the ocular lubricant hydroxypropyl methylcellulose (HPMC). METHODS: In the laboratory, wetting properties of multipurpose solutions with and without HPMC, and binding of HPMC to hydrogel lenses in vitro following an overnight soak, were measured. Tear physiology was evaluated in 35 hydrogel contact lens wearers using multipurpose solutions with and without HPMC. Pre-lens tear evaporation rate (TER), tear thinning time (TTT) and tear film structure (TFS) were recorded, and subjective responses were obtained. RESULTS: Laboratory measurements indicated improved wetting with the HPMC-containing solution, and continued release of HPMC from lenses after an overnight soak in the solution. Pre-lens TTT was longer (p < 0.001) and pre-lens TFS was improved (p = 0.034) with use of the HPMC-containing solution. Pre-lens TER and subjective comparisons did not demonstrate significant differences. CONCLUSIONS: In vitro and in vivo results are consistent with HPMC producing a thicker, longer-lasting layer of fluid on the hydrogel lens, leading to improvements in tear function in contact lens wearers.     

Phenotypic characterization of patients developing chronic dry eye and pain after refractive surgery: A cross-sectional study

PurposeTo describe the clinical characteristics of patients suffering from chronic dry eye (DE) and pain after refractive surgery (RS).MethodsCross-sectional, observational, single-visit study. DE-, pain- and psychological-related symptoms were evaluated with specific questionnaires. DE-related tests evaluated tear osmolarity, conjunctival hyperemia, Meibomian gland dysfunction, tear stability and production, and ocular surface staining. Corneal mechanical sensitivity (Cochet-Bonnet) was measured pre/post topical anesthesia, and symptomatic variation post-anesthesia (anesthetic challenge test) was recorded. When pain was present, it was further categorized as neuropathic or nociceptive based on published criteria.ResultsWe recruited 104 patients (39.5 ± 9.5 years). Most, 85.6%, had corneal RS as opposed to intraocular RS. Migraines, anxiety, depression (p < 0.0001), and central sensitization syndromes (p = 0.0214) were more frequent post-RS than pre-RS. Persistent DE-symptoms, severe in 86.5% patients, developed in a range of 0–204 months post-RS. Dryness and pain were the two most frequent symptoms. The only DE-related tests showing abnormal values were tear osmolarity (315.2 ± 17.1 mOsm/L; normal ≤308) and tear break-up time (4.1 ± 2.5 s; normal >7). Corneal sensitivity was 55.4 ± 7.0 mm, and decreased (p < 0.0001) after topical anesthesia, 6.0 ± 10.4 mm. However, it remained pathologically elevated, ≥10 mm in 61 (58.7%) patients. The normal symptomatic post-anesthesia improvement was absent in 58 (55.7%) patients. Ocular pain was present in 82 (78.8%) patients, and it was categorized as neuropathic in 66 (80.5%) of them, 63.5% of the entire cohort.ConclusionsChronic ocular pain and its neuropathic subtype were diagnosed in 78.8% and 63.5% respectively of patients seeking consultation for persistent symptomatic DE post-RS.     

Increased Tear Film Osmolarity in Systemic Lupus Erythematosus

Purpose: To evaluate tear film osmolarity in patients with systemic lupus erythematosus (SLE). Methods: A total of 55 eyes from 55 patients with SLE and 47 eyes from 47 age- and gender-matched healthy individuals were included in this study. Tear film osmolarity was evaluated with a lab-on-a-chip technique (TearLab; TearLab Corporation, San Diego, CA) in SLE patients in comparison with healthy individuals, and results were correlated to clinically available diagnostic tests for dry eye, such as tear ?lm break-up time (BUT), Schirmer’s test, and Ocular Surface Disease Index (OSDI). Results: The mean tear film osmolarity in the SLE patients and healthy individuals was 306.02 ± 13.27 mOsm/L and 300.74 ± 9.11 mOsm/L, respectively, which made for a statistically significant difference (p = 0.020). In the SLE group, tear film osmolarity was negatively correlated with the Schirmer’s test score and the BUT value (r = ?0.295 p = 0.029 and r = 0.347 p = 0.009, respectively), whereas tear film osmolarity was not correlated with OSDI score (r = ?0.182 p = 0.183). Conclusions: This study revealed that tear film hyperosmolarity and abnormal tear film function are associated with SLE.     

Symptoms in a population of contact lens and noncontact lens wearers under different environmental conditions.

PURPOSE: To investigate ocular symptoms related to dryness in an adult population of contact lens (CL) and non contact lens wearers (n-CL) using video display terminals (VDT) for different periods of time under different indoor conditions related to air conditioning (AC) and heating units (HU) exposure. METHODS: A questionnaire was distributed to 334 people within a university population of which 258 were part of the n-CL group and 76 of the CL wearers to assess symptoms of ocular discomfort potentially related to dryness. Only soft contact lens (SCL) wearers (n = 71) were included for further statistical analysis because of the reduced number of people wearing other lens types. A 2:1 match by gender group of 142 subjects in the n-CL group was used as a control sample. RESULTS: There was a marked difference between the prevalence of symptoms and the way they are reported by CL and n-CL wearers. Red eye, itching, and scratchiness are more common among CL wearers, but the difference is statistically significant only for scratchiness (p < 0.01, chi(2)). The vast majority of subjects who reported symptoms often and at the end of the day are significantly more prevalent among CL wearers (p < 0.01, chi(2)). Gender differences were also encountered. Female CL wearers reported more scratchiness than males in the n-CL wearing group (p = 0.029, chi(2)) and in the CL group (p < 0.008, chi(2)). Females wearing CL reported symptoms of red eye (p = 0.043, chi(2)) and scratchiness (p < 0.001, chi(2)) more significantly than those in the n-CL group. Within the CL group, the prevalence of symptoms occurring sometimes or often and at the end of the day was higher among females (p < 0.001, chi(2)). The use of VDT was associated with a higher level of scratchiness among CL wearers (p < 0.05, chi(2)). The number of hours working with VDTs seemed to be associated with an increase in the prevalence of burning sensation in the CL group (p < 0.01, chi(2)), whereas symptoms like red eye and scratchiness also increased significantly among n-CL wearers. Compared to n-CL wearers, all symptoms increase in CL wearers in environments with AC and HU, except excessive tearing. However, these differences are only statistically significant for scratchiness. CONCLUSIONS: Our results show that people who wear soft CL and work with VDTs for longer periods of time are more likely to develop symptoms like eye burning and scratchiness than n-CL wearers. This risk could be higher for women than men. Scratchiness and the appearance of symptoms near the end of the day are typically associated with ocular discomfort during CL wear in this sample, and clinicians should question their patients about these symptoms to anticipate serious discomfort.     

Assessment of Tear Functions in Patients with Acne Rosacea without Meibomian Gland Dysfunction

Purpose: To evaluate the results of tear functions in acne rosacea.

Methods: This prospective study includes 64 eyes of 32 acne rosacea patients without blepharitis and meibomian gland dysfunction and 90 eyes of 45 patients as control group. Tear functions of all were evaluated with ocular surface disease index (OSDI) questionnaire, and measurements of tear osmolarity were performed by using TearLab, Schirmer I tests without anesthesia and fluorescein tear break-up time (TBUT).

Results: The mean Schirmer test result was 12.53 ± 6.54 in study group and 16.21 + 7.52 mm/5 min in control group (p = 0.28). The mean TBUT in study group was 8.21 ± 4.01 and in control group was 18.03 ± 6.45 s (p = 0.02). Mean tear osmolarity in study group was 304.77 ± 15.59and in control group was 275.23 + 28.52 mOsms/L (p = 0.03). Mean OSDI score in study group was 27.51 ± 16.73 and was 18.15 ± 7.05 in control group (p = 0.38).

Conclusions: Our study demonstrated lower dry eye tests before the appearance of clinical signs of meibomian gland disease in acne rosacea.     

El ojo seco está relacionado con un aumento intrasujeto de la variabilidad de osmolaridad lagrimal confirmado por tecnología de aprendizaje de máquinas

ObjectiveBecause of high variability, tear film osmolarity measures have been questioned in dry eye assessment. Understanding the origin of such variability would aid data interpretation. This study aims to evaluate osmolarity variability in a clinical setting.Material and methodsTwenty dry eyes and 20 control patients were evaluated. Three consecutive osmolarity measurements per eye at 5 min intervals were obtained. Variability was represented by the difference between both extreme readings per eye. Machine learning techniques were used to quantify discrimination capacity of tear osmolarity for dry eye.ResultsMean osmolarities in the control and dry eye groups were 295.1 ± 7.3 mOsm/L and 300.6 ± 11.2 mOsm/L, respectively (P = .004). Osmolarity variabilities were 7.5 ± 3.6 mOsm/L and 16.7 ± 11.9 mOsm/L, for the control and dry eye groups, respectively (P < .001). Based on osmolarity, a logistic classifier showed an 85% classification accuracy.ConclusionsIn the clinical setting, both mean osmolarity and osmolarity variability in the dry eye group were significantly higher than in the control group. Machine learning techniques showed good classification accuracy. It is concluded that higher variability of tear osmolarity is a dry eye feature.