Increase In Lipid Layer Thickness Research Articles

Evaluation of Therapeutic Capability of Emustil Drops against Tear Film Complications under Dry Environmental Conditions in Healthy Individuals.

Background and Objectives: Dry eye disease (DED) is a multifactorial ailment of the tears and ocular surface. The purpose of this study was to assess the tear film physiology under controlled dry environmental conditions and compare the efficacy of oil-in-water emulsion drops on tear film parameters in protection and relief treatment modalities under low-humidity conditions. Emustil eye drops were used after exposure to a low-humidity environment in the relief method, whereas, in the protection method, the drops were applied before exposure to low humidity. Materials and Methods: 12 normal male subjects (mean age 34.0 ± 7.0 years) were exposed to ultra-dry environmental conditions. A number of tear film measurements were carried out under desiccating environmental conditions in a controlled environment chamber (CEC), where the chamber temperature sat at 21 °C with a relative humidity (RH) of 5%. Keeler's TearScope Plus and an HIRCAL grid were used to assess the tear break-up time and lipid layer thickness (LLT), and the evaporation rate was evaluated using a Servomed EP3 Evaporimeter. Results: LLT measurements showed that the dry environment affected LLT significantly (p = 0.031). The median grade of LLT dropped from grade 3 (50-70 nm) at 40% RH to grade 2 (13-50 nm) at 5% RH. A significant increase in LLT was seen after both modes of treatment, with a median LLT grade of 3 when the Emustil was used for both protection (p = 0.004) and relief (p = 0.016). The mean tear evaporation rate in normal environmental conditions (40%) was 40.46 ± 11.80 g/m2/h (0.11 µL/min) and increased sharply to 83.77 ± 20.37 g/m2/h (0.25 µL/min) after exposure to the dry environment. A minimal decrease in tear film evaporation rate was seen in relief; however, statistical tests showed that the decrease in tear film evaporation rate was not significant. Mean NITBUT dropped from 13.6 s at 40% RH to 6.6 s at 5% RH (p = 0.002). All NITBUT measurements at 5% RH (with or without the instillation of Emustil) were significantly lower than those at 40%. The instillation of Emustil at 5% RH resulted in a significant improvement in NITBUT for protection (p = 0.016) but this was not the case for relief (p = 0.0.56). Conclusions: A control environmental chamber (CEC) enables the analysis of tear film parameters comparable to those found in dry eye patients. This enables us to examine the capability of oil in emulsion drops to manage tear film disruption in healthy individuals. This study suggests that using Emustil oil-in-water emulsion before exposure to a dry environment should be advocated for people who work in dry environments.

Impact of virtual reality headset use on eye blinking and lipid layer thickness

Blinking plays an important role in protecting the eyes, and the use of computers has been associated with a reduction in the blink rate. The goal of this study was to evaluate the effect of a virtual reality headset on blinking and lipid layer thickness and to compare these data to those associated with a conventional desktop monitor. Two experiments were performed to compare the effect of 20minutes of use of a virtual reality headset (FOVE) and 20minutes of use of a desktop monitor on the frequency and length of blinks (experiment 1, 15 participants) and on the thickness of the lipid layer as measured by Lipiview (experiment 2, 12 participants). In the first experiment, the blink rate [F(1.83)=4.3, P=0.04, β=0.36] and duration [F(1.83)=13, P=0.001, β=0.35] increased with time under both conditions, but no statistical difference was found between the two conditions (headset vs. desktop monitor) either for blink rate [rmANOVA F(1.11)=0.01, P=0.92; headset: 15.1 blinks, 95% CI: 12.6 to 17.6 blinks; desktop: 14.6 blinks, 95% CI: 13.6 to 15.7 blinks] or for blink duration [rmANOVA F(1.11)=4.534, P=0.06; headset: 205.75ms, 95% CI: 200.9 to 210.6ms; desktop: 202.82ms, 95% CI: 198.2 to 207.5ms]. However, strong individual variations were observed. Evaluation of simulator sickness and visual fatigue by questionnaire showed no significant differences between the two conditions (SSQ simulator sickness questionnaire: V=46, P=0.62; VFQ visual fatigue questionnaire: V=15.5, P=0.13). In the second experiment, the lipid layer thickness increased significantly after use of the VR headset [F(1.18)=11.03, P=0.004, headset: 76.2nm, desktop: 58.8nm]. In terms of recommendations, the effect of virtual reality headsets on blink duration and frequency during a moderate exposure (20minutes) is comparable to that of a conventional desktop monitor. However, the strong individual variations observed, the lack of reliable tests to evaluate this individual sensitivity, and the significant increase in lipid layer thickness in experiment 2 suggest the value of a more detailed investigation, in particular with consideration of a longer exposure time and other tear film parameters.

Increase lipid tear thickness after botulinum neurotoxin A injection in patients with blepharospasm and hemifacial spasm

The aim of this study was to investigate changes in the tear film lipid layer thickness (LLT) and aqueous tear production after botulinum neurotoxin A (BoNT) injection in patients with benign essential blepharospasm (BEB) and hemifacial spasm (HFS). Eleven and six patients with BEB and HFS, respectively, who received BoNT injection were consecutively enrolled in this prospective study. The blepharospasm disability index (BSDI), blink pattern, dry eye symptoms, Schirmer test 1 findings, LLT, eyelid performance, and corneal integrity were evaluated before and after treatment. Both BEB and HSF patients experienced remarkable relief from spasms and ocular discomfort after BoNT injection. LLT, the partial blink rate, the snap-back time, the lid distraction distance, and lateral canthal laxity were significantly increased at 1 month after treatment. There were no significant changes in Schirmer test 1 findings and meibomian gland dropout. Our findings suggest that LLT, a decisive factor for tear film stability, significantly increases at 1 month after BoNT injection for BEB and HFS. A decrease in BSDI and an increase in the snap-back time may contribute to the increase in LLT; this mechanism is probably responsible for the relief from dryness after BoNT injection in patients with facial movement disorders.

Low concentration of sodium hyaluronate temporarily elevates the tear film lipid layer thickness in dry eye patients with lipid deficiency.

To investigate the effects of different concentrations of artificial tears on lipid layer thickness (LLT) and blink rate (BR) in dry eye patients. This study included 106 eyes of 58 patients with dry eye. The lipid deficiency type was defined as the LLT baseline <75 nm. The LLT and BR were measured at baseline and 1, 5 and 15min after the instillation of 0.1% or 0.3% sodium hyaluronate (SH) eye drops by using the LipiView ocular surface interferometer. In the lipid deficiency group, the LLT increased from baseline at 1min post instillation. The LLT after the instillation of 0.1% SH was significantly higher than that after the instillation of 0.3% SH (P<0.001). The LLT returned to baseline at 15min post instillation of 0.1% SH and at 5min post instillation of 0.3% SH. In the non-lipid deficiency group, the LLT decreased from baseline at 1min and returned to baseline at 5min for both treatments. The BRs were not significantly different at different time points for both treatments. SH eye drops induce a short-term increase in LLT of patients with lipid deficiency. A low concentration of artificial tears have a stronger effect than a high concentration of artificial tears on the increase in LLT. In comparison, SH eye drops induce a transient and slight decrease in LLT of patients without lipid deficiency. A low concentration of artificial tears might be better for patients with lipid deficiency.

The Effect of Optive and Optive Advanced Artificial Tears on the Healthy Tear Film

ABSTRACTPurpose: To evaluate the impact of Optive (Allergan, Irvine, CA) and Optive Advanced (Allergan, Irvine, CA) on tear film stability and quality during a one-hour observation period when compared to saline (Pfizer, Perth, WA).Methods: This was a double-masked, cross-over study. Twenty participants attended three visits, randomly receiving either Optive, Optive Advanced or saline. Oculus Keratograph 5M (Oculus, Arlington, WA, USA), non-invasive keratograph break-up time (NIKBUT), Lipiview (TearScience Inc, Morrisville, NC, USA), lipid layer thickness (LLT) and comfort were measured prior to and 5, 15 and 60 min after drop instillation.Results: Optive Advanced demonstrated a significant increase in LLT between baseline (57.5 ± 12.3 nm) and both 5 min (67.5 ± 18.8 nm, p = 0.04) and 15 min (68.9 ± 17.3 nm, p = 0.04) but not 60 min (61.6 ± 14.3 nm, p = 0.47). Optive and saline were not different between timepoints for LLT (p > 0.05). There was no difference between timepoints for any of the drops for NIKBUT (p = 0.75). Comfort was significantly better at 5 min compared to baseline for Optive (8.3 ± 1.2 and 7.3 ± 1.4, respectively, p = 0.03) but not different for Optive Advance or saline (p > 0.05).Conclusions: Optive Advanced increased LLT for 15 min following instillation, returning to baseline within one hour. This did not however, translate into an improvement in tear film stability over this time period. Only Optive demonstrated an improvement in comfort.

Increase in tear film lipid layer thickness after instillation of 3% diquafosol ophthalmic solution in healthy human eyes

PurposeTo evaluate the effect of 3% diquafosol ophthalmic solution on tear film lipid layer thickness (LLT) in normal human eyes by tear interferometry. MethodsForty-seven healthy men (mean age of 42.4 years) randomly received one drop of artificial tears in one eye and one drop of 3% diquafosol ophthalmic solution in the other. LLT of each eye was quantified by tear interferometry before and 15, 30, and 60 min after instillation. Ocular symptoms were assessed before and 30 min after instillation. Baseline LLT, tear film breakup time (TBUT), meibomian gland area (meiboscore) of the upper and lower eyelids, and Schirmer test value were evaluated on a different day before treatment. ResultsLLT before and 15, 30, and 60 min after diquafosol instillation was 62.3 ± 31.1, 77.0 ± 39.5, 79.3 ± 40.5, and 77.7 ± 43.6 nm, respectively, with the diquafosol-induced increase in LLT being significant at each time point. Artificial tears did not result in a significant increase in LLT. TBUT (ρ = 0.32, P = 0.026), meiboscore of the lower eyelid (ρ = −0.33, P = 0.022), and the maximum difference in LLT between before and after diquafosol instillation (ΔLLTmax) (ρ = 0.35, P = 0.016) were significantly correlated with baseline LLT in the diquafosol group. Age was not significantly related to baseline LLT or ΔLLTmax. Symptoms did not differ significantly between the two groups. ConclusionsTopical instillation of 3% diquafosol ophthalmic solution increased LLT for up to 60 min in normal human eyes regardless of age.

Effect of lipid-based dry eye supplements on the tear film in wearers of eye cosmetics.

To compare the effects on tear film parameters and contamination in cosmetic eyeliner wearers, after single application of two lipid-based dry eye treatments: a lipid-containing lubricant eye drop and a phospholipid liposomal spray. Fifty participants were enrolled in a prospective, randomised, paired-eye, investigator-masked trial. Pencil eyeliner (Body Shop® Crayon Eye Definer) was applied to the upper eyelid periocular skin of both eyes, anterior to the lash line. Baseline tear film quality was assessed fifteen minutes after eyeliner application. A lubricant drop (Systane® Balance) was then applied to one eye (randomised), and liposomal spray (Tears Again®) to the contralateral eye. Tear film contamination, lipid layer grade, non-invasive tear film break-up time and tear evaporation rate were evaluated fifteen minutes post-treatment and compared to pre-treatment values. Pre-treatment measurements did not differ between eyes assigned to lubricant drop and liposomal spray. Tear film contamination was observed in a greater proportion of eyes following both treatments (both p<0.05), with no significant difference between treatments (p=0.41). Both treatments improved lipid layer thickness (both p≤0.01), but effected no significant change in non-invasive tear film break-up time or tear evaporation rate (all p>0.05). Changes in tear film parameters did not differ between treatments (all p>0.05). Both the lipid-containing lubricant eye drop and phospholipid liposomal spray result in clinically apparent tear film contamination in eyeliner cosmetic wearers. Although both treatments effected an increase in lipid layer thickness, neither displayed clinical efficacy in improving tear film stability.

Tear lipid layer thickness with eye drops in meibomian gland dysfunction.

PurposeThe aim of this study was to evaluate the efficacy of a lipid containing emollient eye drop, Soothe XP, which was reformulated in 2014 with a more stable preservative and buffer system, compared to a control, non-emollient, eye drop (Systane Ultra) in improving lipid layer thickness (LLT) in subjects with dry eye due to meibomian gland dysfunction (MGD).Patients and methodsThis prospective single-center, open-label, cross-over, examiner masked-study enrolled subjects aged 30–75 years with lipid-deficient dry eye and a clinical diagnosis of MGD as determined by a slit lamp examination, an evaluation of meibomian gland drop out with meibography, and a standard patient evaluation of eye dryness questionnaire of >5. Eligibility was then determined by a LLT of <75 nm at baseline and the inability to increase LLT ≥15 nm with three blinks, as determined by interferometric methods. Subjects were randomized to receive a single emollient or non-emollient eye drop at Visit 1 and were crossed over for the alternate treatment at Visit 2. At each visit, LLT was measured prior to and 15 minutes following the instillation of the assigned eye drop. The primary endpoint was the change in LLT from baseline.ResultsSubjects (n=40) were enrolled and 35 completed the two study arms. Mean (±SD) patient age was 55.7 years (10.9) and 69% were female. Mean (±SD) LLT at baseline was 49.5 nm (9.2). Instillation of Soothe XP resulted in an increase in LLT to 77.5 nm (29.3) 15 minutes following drop instillation, which is an increase of 28.0 nm (27.4) (P<0.001). In contrast, LLT 15 minutes after the instillation of Systane Ultra was 50.8 nm (14.1), which was not statistically significant when compared to the baseline LLT.ConclusionIn this study of subjects with MGD, the emollient, or lipid containing eye drop, increased the LLT of tears when measured 15 minutes after instilling a single eye drop.

Comparison of the Efficacy of Two Lipid Emulsion Eyedrops in Increasing Tear Film Lipid Layer Thickness

The lipid layer of the tear film is critical to maintaining the thickness of the multilayered tear film. This study was designed to determine whether a single drop of Refresh Dry Eye Therapy or Soothe, both lipid emulsion eyedrops, significantly increased the lipid layer thickness (LLT) of patients with self-reported dry eyes and thin lipid layers. Lipid layer interference patterns were used to quantify the LLT of both eyes of eligible patients before and after test drop instillation. Patients (n=41) reporting dry eye symptoms and having baseline LLT of no more than 75 nm received 40 microL of Refresh Dry Eye Therapy in one eye and 40 microL of Soothe in the contralateral eye. After instillation, LLT was quantified at 1, 5, and 15 minutes. LLT after drop instillation was averaged for the three time points. The mean +/- standard error baseline LLT was 59.6 +/- 1.7 nm for eyes treated with Refresh Dry Eye Therapy and 61.5 +/- 1.6 nm for eyes treated with Soothe. These means were not significantly different (P>0.05). The overall mean LLT after drop instillation was 83.2 +/- 3.6 nm for Refresh Dry Eye Therapy (P<0.0001) and 121.5 +/- 3.8 nm for Soothe (P<0.0001). The mean LLT increase from Soothe (60.0 nm) was significantly greater than that from Refresh Dry Eye Therapy (23.6 nm) (P<0.0001). The application of a lipid emulsion eyedrop will increase LLT and benefit patients with deficient lipid layers who experience dry eye symptoms. Although both products are lipid emulsions, one drop of Soothe essentially doubled LLT and provided a mean increase in LLT that was 2.5 times greater than that of Refresh Dry Eye Therapy.

The Effect of Two Novel Lubricant Eye Drops on Tear Film Lipid Layer Thickness in Subjects With Dry Eye Symptoms

Because the lipid layer of the tear film is recognized as a critical component in dry eye disease, this study was designed to determine if a single eye drop of either Soothe or Systane produces a significant increase in lipid layer thickness (LLT) for subjects reporting symptoms indicative of dry eyes. A double-blind, internally paired study was performed. A custom-built lipid layer interferometer, enabling characterization of lipid layer interference patterns, was used to quantify baseline LLT (OU) of eligible subjects. Inclusion criteria included: 1) presence of dry eye symptoms and 2) baseline LLT < or =75 nm. Subjects (n = 40) received a single eye drop of Soothe in one eye and a single eye drop of Systane in the contralateral eye. After the instillation of each test drop, LLT was reanalyzed for all subjects. The mean +/- standard error baseline LLT pre-eye drop instillation was 60.0 +/- 1.8 nm for eyes treated with Soothe and 61.5 +/- 1.8 nm for eyes treated with Systane. These means were not significantly different (p > 0.5). The mean LLT for eyes treated with Soothe increased to 124.4 +/- 4.9 nm (p < 0.0001). The mean LLT for eyes treated with Systane increased to 71.3 +/- 2.6 nm (p < 0.0001). The LLT increase from Soothe was significantly greater than that from Systane (p < 0.0001). In subjects with symptoms indicative of dry eye states and LLT < or =75 nm, one eye drop of Soothe more than doubled LLT, a 107% mean increase, whereas Systane increased LLT by 16%.

Tear film lipid layer thickness as a function of blinking.

Alterations in the tear film lipid layer as a function of blinking were investigated using a custom-designed specular reflection monitoring system. The tear film lipid layer of 104 subjects under conditions of normal ("baseline") blinking and "forceful" blinking was quantitated on the basis of specific interference colors. Deliberate, forceful blinking was found to significantly increase the lipid layer thickness (LLT) of the tear film. The magnitude of increase was found to be correlated with the baseline LLT values; individuals with baseline LLT values of 75-150 nm demonstrated a mean increase in LLT of 33 nm following forceful blinking, whereas subjects with baseline LLT values < or = 60 nm experienced a mean increase of 19 nm. The difference in the magnitude of increase between the groups was highly significant (p = 0.0001). The data suggest that, in addition to playing a role in the spreading of lipid across the tear film, the blinking mechanism may be important in the maintenance of the lipid layer by augmenting the expression of lipids from the meibomian glands.