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

Associations with meibomian gland loss in soft and rigid contact lens wearers

Understanding the Dual Dilemma of Dry Eye and Glaucoma: An International Review.

Purpose To determine whether tear osmolarity using the TearLabTM Osmolarity System contributes to the assessment of the ocular surface in contact lens (CL) wearers.Methods Data were collected from 44 CL wearers (28 tolerant and 16 intolerant) and 34 healthy subjects. Every patient underwent a thorough ophthalmic examination and tear osmolarity test, 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 was significantly higher in the controls compared to tolerant and intolerant CL wearers (p=0.0007). Flow cytometry results expressed in antibody‐binding capacity (ABC) units and percentage of positive cells revealed a significant difference between intolerant CL wearers group and control group (p<0.0001). Moreover, impression cytology analysis showed similar values in the tolerant CL wearers and the control group. 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=0.98) between groups.Conclusion CL wear is responsible for ocular surface alterations whose patterns are very similar to those reported in dry eye syndrome. However, the yield of tear osmolarity with TearLabTM in assessing ocular surface disorders in CL wearers deserves further investigation.

BackgroundThe aim of this study was to explore the differences in terms of tear film and meibomian glands (MGs) between young Asian soft contact lens (CL) wearers and non-wearers.MethodsA prospective, cross-sectional observational study was conducted using 148 subjects (63 non-wearers, and 85 soft CL wearers who had been wearing CLs for more than 1 year) recruited from a clinic in Tianjin, China. All subjects first responded to an Ocular Surface Disease Index (OSDI) questionnaire and then underwent a standardized dry eye examination, which included measuring tear meniscus height (TMH), non-invasive tear breakup time (NIBUT), and corneal fluorescein staining (CFS). The MGs were evaluated via ImageJ, distorted MG count and the MG dropout were recorded.ResultsCompared to the control group (non-wearers), the CL group recorded higher OSDI and CFS scores, lower TMH and NITBUT values, a larger distorted MG count, and larger MG dropout (all P < 0.05). Pearson correlation analysis found a correlation between MG dropout and the duration of CL use (r = 0.440, P < 0.001), OSDI (r = 0.298, P = 0.006), and CFS scores (r = 0.442, P < 0.001).ConclusionCL wearers showed higher MG dropout and reduced TMH and NITBUT, which likely contributes to severe CL-related dry eye symptoms. CL use may lead to a higher MG dropout rate, and the extent of the MG dropout presumably influences the tear film status in CL wearers.

As contact lens (CL) wear affects the ocular surface, this cross-sectional study aims to assess the effects of soft CL wear and its duration on the tear film and meibomian gland (MG) drop-out and visibility. Thirty non-CL wearers (22.5 ± 2.3 years) and twenty-four soft CL wearers (23.8 ± 2.2 years) participated in this study. The Keratograph 5M was used to assess the ocular surface. CL users were surveyed on years of CL wear and hours per week. MG visibility was assessed using a previously developed method based on analysing pixel intensity of meibographies. The CL group showed higher gland drop-out (p < 0.001) and lower gland visibility (p < 0.022). Gland drop-out was independently associated with CL wear (p = 0.006). When gland drop-out was excluded, the relative energy of pixel intensity values showed an independent association with CL wear (p = 0.005). Prolonged hours of CL wear were associated with higher dry eye symptoms and entropy of MGs (p < 0.029). A reduction in non-invasive keratograph break-up time was associated with using CLs for ≥8 years (p = 0.030). Overall, gland drop-out was higher and gland visibility lower in soft CL wearers. New gland visibility metrics might help to assess MGs in soft CL wearers quickly and objectively.

To assess the potential additive effects of short-term display use and contact lens (CL) wear on the ocular surface and tear film. Thirty-four healthy volunteers (20.87±2.33years old) participated in this study. Participants' dry eye symptoms, ocular surface, tear film and pupil size were assessed before and after executing a 20-min reading task on a computer and a smartphone with and without CL wear, or with CL wear and artificial tear instillation. Measurements included the Ocular Surface Disease Index (OSDI) questionnaire; 5-item Dry Eye Questionnaire (DEQ-5); tear meniscus height (TMH); noninvasive keratograph break-up time (NIKBUT); bulbar conjunctival redness (BR) and pupil size. Higher symptoms were reported after reading on both displays with and without CLs (p≤0.001) for short periods. BR was higher and NIKBUT shorter after reading on the computer regardless of wearing CLs (p≤0.02 and p≤0.02, respectively), while TMH increased for all conditions (p≤0.02) except for CL computer reading (p=0.23). Reading with CLs did not lead to greater signs of dry eye (BR, NIKBUT) and symptoms compared with reading unaided (p>0.05), although a smaller increase in TMH was observed when reading on the computer with CLs (p=0.005). Artificial tear instillation during CL wear led to a smaller increase in symptoms (p≤0.02), a smaller increase in BR (p≤0.04) and a decrease in NIKBUT (p=0.02) compared to reading without correction. Disposable CL wear had no additive effects on signs and symptoms of dry eye when using digital devices for short periods. The instillation of artificial tears is an effective strategy for reducing the impact of display use in CL wearers.

This study addressed the utilisation of machine learning techniques to estimate tear osmolarity, a clinically significant yet challenging parameter to measure accurately. Elevated tear osmolarity has been observed in contact lens wearers and is associated with contact lens-induced dry eye, a common cause of discomfort leading to discontinuation of lens wear. The study explored machine learning, regression and classification techniques to predict tear osmolarity using routine clinical parameters. The data set consisted of 175 participants, primarily healthy subjects eligible for soft contact lens wear. Various clinical assessments were performed, including symptom assessment with the Ocular Surface Disease Index and 5-Item Dry Eye Questionnaire (DEQ-5), tear meniscus height (TMH), tear osmolarity, non-invasive keratometric tear film break-up time (NIKBUT), ocular redness, corneal and conjunctival fluorescein staining and Meibomian glands loss. The results revealed that simple linear regression was insufficient for accurate osmolarity prediction. Instead, more advanced regression models achieved a moderate level of predictive power, explaining approximately 32% of the osmolarity variability. Notably, key predictors for osmolarity included NIKBUT, TMH, ocular redness, Meibomian gland coverage and the DEQ-5 questionnaire. In classification tasks, distinguishing between low (<299 mOsmol/L), medium (300-307 mOsmol/L) and high osmolarity (>308 mOsmol/L) levels yielded an accuracy of approximately 80%. Key parameters for classification were similar to those in regression models, emphasising the importance of NIKBUT, TMH, ocular redness, Meibomian glands coverage and the DEQ-5 questionnaire. This study highlights the potential benefits of integrating machine learning into contact lens research and practice. It suggests the clinical utility of assessing Meibomian glands and NIKBUT in contact lens fitting and follow-up visits. Machine learning models can optimise contact lens prescriptions and aid in early detection of conditions like dry eye, ultimately enhancing ocular health and the contact lens wearing experience.

To analyze differences in the ocular surface appearance and tear film status of contact lens wearers and non-wearers in a group of visual display terminals (VDT) workers and additionally to assess differences between lens materials. Cross-sectional study of 236 office workers, of whom 92 were contact lens wearers. Workers provided information on their contact lenses (conventional hydrogel, silicone hydrogel or rigid gas permeable lenses) and exposure to VDT at work. Ocular surface and tear film status were determined by the presence of bulbar, limbal and lid redness, lid roughness and corneal staining type, and by Schirmer's and tear break-up time tests (TBUT). A generalized linear model was used to calculate the crude (cRR) and age- and sex-adjusted (aRR) relative risk to measure the association between ocular surface and tear film abnormalities and contact lens use and type. The aRR of ocular surface abnormalities was higher in contact lens wearers compared to non-wearers: bulbar redness (aRR 1.69; 95% CI 1.25-2.30), limbal redness (aRR 2.87; 1.88-4.37), lid redness (aRR 2.53; 1.35-4.73) and lid roughness (aRR 7.03; 1.31-37.82). VDT exposure > 4h/day increased wearers' risk of limbal and lid redness. Conventional hydrogel wearers had the highest risk of ocular surface abnormalities, followed by silicone hydrogel wearers. Both contact and non-contact lens wearers had a high prevalence of altered TBUT (77.3 and 75.7% respectively) and Schirmer (51.8 and 41.3%). Regular contact lens use during VDT exposure at work increases risk of bulbar, limbal and lid redness, and lid roughness, especially in soft contact lens wearers. The high prevalence of altered TBUT and Schirmer's results in all participants suggests that VDT use greatly affects tear film characteristics.

Contact Lens Wear Is Associated with Decrease of Meibomian Glands

PurposeTo evaluate the effect of a single vectored thermal pulsation (VTP) treatment in contact lens wearers with meibomian gland dysfunction (MGD) and dry eye symptoms.MethodsThe prospective, nonsignificant risk, open-label, randomized, multi-center clinical trial included 55 soft contact lens (SCL) wearers with MGD and evaporative dry eye. Subjects were randomized to the single VTP treatment group or an untreated control. The controls received a crossover VTP treatment at 3 months (crossover treatment group). Primary effectiveness measures were meibomian gland secretion (MGS) score and Standard Patient Evaluation of Eye Dryness (SPEED) that were evaluated at baseline, at 1 and 3 months post-VTP treatment, and at 1 month post-VTP treatment in the crossover treatment group. Exploratory variables included fluorescein tear break-up time (TBUT), lid wiper epitheliopathy (LWE), lid parallel conjunctival folds (LIPCOF), ocular surface staining, frequency of over-the-counter (OTC) drop use, and hours of comfortable contact lens wear.ResultsAt 3 months, the treatment group showed significantly greater mean change from baseline in MGS (12.4±9.1 vs 1.4±6.4, p<0.0001), SPEED (−8.4±4.7 vs −0.7±4.4, p<0.0001) and significantly greater improvement in exploratory variables (TBUT, LWE, and frequency of OTC drop use) relative to the controls. Mean comfortable contact lens wearing time increased by 4.0±3.9 hours at 1 month. This was sustained for 3 months with no change in the control group. The crossover treatment group demonstrated similar results to the treatment group at 1 month post-VTP.ConclusionIn SCL wearers with MGD, a single VTP treatment significantly improved mean meibomian gland function and significantly reduced dry eye signs and symptoms compared to an untreated control. The treatment increased mean comfortable lens wearing time by 4 hours (approximately doubling the pretreatment findings). This was sustained for up to 3 months post-treatment on average.

The aim of the study was to investigate the relationship between daily soft contact lens (CL) wear and various signs of ocular involvement. We focused on comprehensive meibomian gland (MG) evaluation, including both functional and morphological parameters of the MGs. The ocular surface and MG characteristics were evaluated in 41 daily soft CL users and 31 age-matched non-lens wearers. We analyzed the MG function (meibum quality and meibum expressibility) and morphology (meibography) and evaluated lid margin alterations. We also correlated our findings with self-reported ocular symptoms and tear film abnormalities (tear film breakup time and Schirmer test values). CL use was associated with abnormal meibum quality [higher meibum quality score, odds ratio (OR) = 2.7, 95% confidence interval (CI), 1.3-5.6, P = 0.0057], more frequent bulbar (OR = 3.6, 95% CI, 1.5-8.2, P = 0.0028) and palpebral (OR = 2.4, 95% CI, 1.1-5.1, P = 0.028) conjunctival hyperemia, lid margin telangiectasia (OR = 6.0, 95% CI, 2.4-14.6, P < 0.00001), rounding (OR = 9.3, 95% CI, 1.1-81.0, P = 0.04), notching (OR = 3.9, 95% CI, 1.2-12.4, P = 0.019), hyperemia (OR = 4.3, 95% CI, 1.3-14.1, P = 0.015) of the posterior lid margin, orifice plugging (OR = 4.8, 95% CI, 1.3-17.1, P = 0.015), and retroplacement (OR = 0.8, 95% CI, 0.4-1.9, P = 0.037) after adjustment for age and sex in a logistic regression model. Lid margin abnormality and meibum quality scores strongly positively correlated with the duration of CL wear. These associations remained significant after adjustment for age and sex (P = 0.00003 and P = 0.01, respectively). CL wear may predispose individuals to meibomian gland dysfunction, which is not usually investigated unless significant symptoms are present. Therefore, we recommend to routinely examine CL wearers for meibomian gland dysfunction manifestations and to introduce specific prophylaxis if required.

Contact Lens Comfort.

Topical review of the relationship between contact lens wear and meibomian gland dysfunction

Intravitreal injections and endophthalmitis risk

This study demonstrates that asymptomatic habitual soft contact lens (CL) wearers have lower tear aqueous production (TAP) rates compared with non-lens wearers, while symptomatic wearers have higher rates than those of asymptomatic wearers. These findings suggest that the impact of soft CL on TAP rate may differ between symptomatic and asymptomatic soft CL wearers. To understand the role of TAP rate in symptomatic and asymptomatic soft CL wearers, the TAP rate was measured for four groups: symptomatic CL wearers who remain symptomatic after CL removal (dry eye); symptomatic CL wearers who become asymptomatic after CL removal (contact lens-induced dry eye); asymptomatic CL wearers; asymptomatic non-CL wearers. Subjects were grouped based on responses to the Berkeley Dry Eye Flow Chart. TAP rate was measured by the modified (sheathed) Schirmer strip test. A recent study showed that TAP rate reached a peak between 12:00 and 14:00 hours; therefore, visit times were designated as "before peak," "peak," and "after peak." The between-group difference in TAP rate was modeled as a fixed effect in a linear mixed model, adjusting for random effects (between-eye correlation, repeated visits) and confounding factors (demographics, visit time, and ocular surface diagnoses). Data from 115 subjects were analyzed. The grand mean (standard deviation) TAP rate was 1.2 (0.92) µL/min. The mean TAP rate of asymptomatic CL wearers was the lowest among the study groups. Compared with asymptomatic CL wearers, the adjusted mean difference (95% confidence interval) in the TAP rate for asymptomatic non-CL wearers, contact lens-induced dry eye, and dry eye groups were 0.49 (0.09~0.89; p=0.02), 0.44 (0.02~0.86; p=0.04), and 0.56 (0.05~1.07; p=0.03) µL/min higher during the "before peak" period (i.e., in the morning), respectively. In the morning, asymptomatic CL wearers show lower TAP rates than asymptomatic non-CL wearers, suggesting that habitual CL wear may reduce TAP rate. Symptomatic CL wearers also have higher TAP rates compared to asymptomatic wearers. Further research is warranted to determine how TAP rate differs between the two symptomatic groups to advance our understanding of the interplay between soft CL wear and TAP rate and to shed additional insights into mechanisms for CL discomfort.