Symptoms, visual function, and mucin expression of eyes with tear film instability

Relationship Between Ocular Surface Epithelial Damage, Tear Abnormalities, and Blink in Patients With Dry Eye

PURPOSE

Considering that tears play the role of a lubricant, it is speculated that in the pathophysiology of dry eye, increased friction during blinking results in corneal and conjunctival damage, which may subsequently affect the blink. The purpose of this study was to investigate the relationship between ocular surface epithelial damage, tear abnormalities, and blinks in patients with dry eye.

METHODS

This study involved 45 eyes of 45 female patients with dry eye (mean age: 57.6 years). In all eyes, tear meniscus radius (mm), spread grade of the tear film lipid layer (SG: 1-5: 1 being the best), fluorescein breakup time (FBUT, seconds), corneal and bulbar conjunctival epithelial damage (CED: 15 points maximum and CONJUNCTIVAL EPITHELIAL DAMAGE (CjED): 6 points maximum, respectively), and Schirmer I test (ST1, mm) were evaluated. Blink rate (BR, blinks per minute), palpebral aperture height (mm), upper-eyelid opening-phase amplitude/upper-eyelid closing-phase amplitude (mm), upper-eyelid opening-phase duration/upper-eyelid closing-phase duration (ms), and upper-eyelid opening-phase maximum velocity/upper-eyelid closing-phase maximum velocity (mm/s) were measured using a custom-made high-speed blink analyzer. Finally, the factors that determine CED and CjED were investigated by multiple regression analysis, in which the parameters were chosen using the stepwise procedure.

RESULTS

CED and CjED were found to be described as 2.687 + (1.816 × SG) - (0.937 × FBUT) (R = 0.656, P < 0.0001) and 0.684 + (0.801 × SG) - (0.526 × FBUT) - (0.041 × ST1) + (0.010 × upper-eyelid closing-phase maximum velocity) (R = 0.714, P < 0.0001), respectively.

CONCLUSIONS

Although CED was significantly related to only tear abnormalities, CjED was significantly related to tear abnormalities and blinking.

Air pollutant particulate matter 2.5 induces dry eye syndrome in mice

In this study, we explored the effects of particulate matter 2.5 (PM_2.5) eye drops on the ocular surface structure and tear function in mice and established a novel animal model for dry eye research. We found that, following treatment with PM_2.5, the tear volume and, the tear film break-up time showed statistical differences at each time point (P < 0.05). The FL score of the PM_2.5-treated group was higher than that of others (P < 0.05). The average number of corneal epithelial layer cells in groups A and B was significantly lower than that in group C (P < 0.05). Scanning electron microscopy and transmission electron microscopy revealed that the number of corneal epithelial microvilli and corneal desmosomes was drastically reduced in group C. PM_2.5 induced apoptosis in the corneal superficial and basal epithelium and led to abnormal differentiation and proliferation of the ocular surface with higher expression levels of Ki67 and a reduced number of goblet cells in the conjunctival fornix in group C. PM_2.5 significantly increased the levels of TNF-α, NF-κB p65 (phospho S536), and NF-κB in the cornea. Thus, the topical administration of PM_2.5 in mice induces ocular surface changes that are similar to those of dry eye in humans, representing a novel model of dry eye.

Reconsidering the central role of mucins in dry eye and ocular surface diseases

Mucins are key actors in tear film quality and tear film stability. Alteration of membrane-bound mucin expression on corneal and conjunctival epithelial cells and/or gel-forming mucin secretion by goblet cells (GCs) promotes in ocular surface diseases and dry eye disease (DED). Changes in the mucin layer may lead to enhanced tear evaporation eventually contributing to tear hyperosmolarity which has been associated with ocular surface inflammation. Inflammatory mediators in turn may have a negative impact on GCs differentiation, proliferation, and mucin secretion. This sheds new light on the position of GCs in the vicious circle of DED. As contributor to ocular surface immune homeostasis, GC loss may contribute to impaired ocular surface immune tolerance observed in DED. In spite of this, there are no tools in routine clinical practice for exploring ocular surface mucin deficiency/dysregulation. Therefore, when selecting the most appropriate treatment options, there is a clear unmet need for a better understanding of the importance of mucins and options for their replacement. Here, we comprehensively revisited the current knowledge on ocular surface mucin biology, including functions, synthesis, and secretion as well as the available diagnostic tools and treatment options to improve mucin-associated homeostasis. In particular, we detailed the potential link between mucin dysfunction and inflammation as part of the uncontrolled chronic inflammation which perpetuates the vicious circle in DED.

Therapeutic effects of 3% diquafosol ophthalmic solution in patients with short tear film break-up time-type dry eye disease

Background

To investigate therapeutic effects of topical diquafosol tetrasodium 3% ophthalmic solution in patients with short tear film break-up time (TFBUT)-type dry eye (DE).

Methods

The prospective study was performed in 70 eyes of 70 patients with short TFBUT-type DE. Diagnosis of short TFBUT-type DE was made based on the presence of DE symptoms, TFBUT value ≤5 s, corneoconjunctival staining score ≤ 2 (on a scale of 0 to 4), and Schirmer I value > 5 mm. Patients with systemic immunologic disorders or ocular graft-versus-host disease were excluded. Before and after instillation of 3% diquafosol ophthalmic solution six times per day for 4 weeks, subjective DE symptoms, TFBUT, corneoconjunctival staining score, and Schirmer I value were examined and compared. Also, demographic factors were compared between patients who showed improvement in each DE parameter by treatment and those who did not.

Results

Four-week treatment with 3% diquafosol ophthalmic solution significantly improved DE symptoms (p < 0.0001), increased TFBUT (p < 0.0001), and reduced corneoconjunctival staining scores (p < 0.0001). Schirmer I values were not changed by treatment. The age of patients who showed improvement in subjective DE symptoms after treatment was significantly lower than that of patients who did not (53.4 ± 27.5 vs. 63.3 ± 13.9 years, p = 0.012). Ocular side effects developed in 3 patients (4.3%), including conjunctival chemosis (n = 1) and persistent stinging sensation (n = 2).

Conclusions

Diquafosol tetrasodium 3% ophthalmic solution is effective in improving subjective symptoms and tear film stability in short TFBUT-type DE patients.

Trial registration

The study was retrospectively registered on Clinical Research Information Service (CRiS), Republic of Korea.

Trial registration number: KCT0003134.

Date of registration: 2018-08-15.

Quality of life measures and health utility values among dry eye subgroups

Background

To determine whether quality of life (QOL) and health utility are affected to the same extent among dry eye (DE) patients with short tear film break-up time dry eye (TBUT-DE) with minimal clinical signs were as severe as aqueous-deficient dry eye (ADDE).

Methods

A multicenter cross-sectional study was conducted among DE patients who visited one of 10 eye clinics in Japan. Among the 463 registered patients, this study involved 449 patients with DE who were aged 20 years or older. Ophthalmic examination findings were assessed, including tear film break-up time (TBUT), Schirmer I value, and keratoconjunctival staining score. QOL was evaluated with the Dry Eye-Related Quality-of-Life Score (DEQS; 0 [best], 100 [worst]) and health utility (1 [total health], 0 [worst]) with the Health Utilities Index Mark 3 (HUI-3); scores were stratified by DE subgroup.

Results

Median (interquartile range) of DEQS and HUI-3 scores across all participants were 21.7 (10.0–40.0) and 0.82 (0.69–0.91), respectively. Median (interquartile range) DEQS and HUI-3 scores in the ADDE group were 23.3 (10.0–40.0) and 0.79 (0.69–0.88), respectively; those in the short TBUT-DE group were 23.3 (13.3–38.3) and 0.82 (0.74–0.92), respectively. There were no significant between-group differences in questionnaire scores. Among the ophthalmic examination findings, a weak significant correlation between TBUT, corneal staining score and keratoconjunctival staining score to DEQS; TBUT and Schirmer test values to HUI-3, were seen.

Conclusions

The burden of short TBUT-DE on QOL as assessed by the DEQS and HUI-3 was as severe as that in ADDE. Our findings suggest that clinicians should be aware of the impact of short TBUT-DE on patients QOL and utility values.

Trial registration

University Hospital Medical Information Network (registration no. UMIN 000015890). Registered 10th December 2014, retrospectively registered.

Randomized Controlled Study to Investigate the Effect of Topical Diquafosol Tetrasodium on Corneal Sensitivity in Short Tear Break-Up Time Dry Eye

INTRODUCTION

Complex mechanisms underlie dry eye (DE) symptom provocation. In particular, corneal hypersensitivity may provoke symptoms in short tear break-up time (BUT) DE characterized by tear film instability. We hypothesized that improved tear film stability may alleviate corneal sensitivity in patients with short tear BUT DE. Therefore, we investigated the effect of topical diquafosol tetrasodium (DQS) on corneal sensitivity in unstable tear film DE.

METHODS

This prospective, randomized study included 27 subjects (age: 39.1 ± 8.4 years; range: 25-59 years) with short tear BUT DE, defined based on the presence of DE symptoms and tear film instability. Subjects were randomly divided into DQS (3% DQS, 12 subjects) and artificial tear (AT; preservative-free AT, 15 subjects) groups. Subjects applied the medication 6 times a day for 5 weeks. The perception of touch (S-touch) and pain (S-pain) sensitivity was measured using a Cochet-Bonnet esthesiometer. Tear evaluation, corneal sensitivity, and DE symptoms were compared before and after DQS or AT administration. The correlation between the improvement degrees of corneal sensitivity and DE symptoms following medication was analyzed.

RESULTS

DQS significantly improved tear BUT and tear meniscus height (TMH) scores (p < 0.05), while AT significantly improved tear BUT (p < 0.05) but not TMH score. Mean S-pain and DE symptom scores were lower after medication use in the DQS (S-pain and DE symptoms: p  < 0.05) and AT groups (S-pain: p  = 0.05; DE symptoms: p  < 0.05). However, S-touch did not change significantly in either group. A positive correlation was observed between the improvement degrees of S-pain and DE symptoms in the overall subjects studied.

CONCLUSION

Both DQS and AT alleviate corneal hypersensitivity and DE symptoms in eyes with short tear BUT DE. However, DQS seems to be more effective to adjust tear environment, leading to the normalization of corneal sensitivity and DE symptoms.

TRIAL REGISTRATION

UMIN Clinical Trials Registry Identifier, UMIN000014536.

Influence of glaucoma surgery on the ocular surface using oculus keratograph

PURPOSE

To investigate the influence of trabeculectomy and phacotrabeculectomy on the ocular surface.

DESIGN

Retrospective, case-control study.

METHODS

Eighty-one samples without dry eyes were recruited and divided into three groups, including phacoemulsification group (N = 30) as control group, trabeculectomy group (N = 27) and phacotrabeculectomy group (N = 24) as study groups. Ocular surface parameters, including noninvasive keratograph first (NifBUT) and average (NiaBUT) tear film breakup time, tear meniscus height (TMH) and corneal fluorescein stain (CFS), were estimated preoperatively, at 3 days, 1 month and 3 months postoperatively using oculus keratograph.

RESULTS

No significant difference was observed in ocular surface parameters at baseline among three groups (p > 0.05). The magnitude of NifBUT and NiaBUT was reduced at 3 days and 1 month postoperatively in phacotrabeculectomy group, but greater than that in the other two groups (All p < 0.001). In all the groups, both the NifBUT and NiaBUT tended to recover at 1 and 3 months postoperatively, whereas both of them did not recover to baseline at 3 months postoperatively in trabeculectomy (NifBUT, p = 0.001; NiaBUT, p < 0.001) and phacotrabeculectomy group (NifBUT, p < 0.001; NiaBUT, p = 0.020). TMH was raised at 3 days postoperatively and restored to the baseline level at 1 and 3 months postoperatively for three groups (p > 0.05). CFS was elevated at 3 days postoperatively and different in recovery at 1 and 3 months postoperatively for three groups.

CONCLUSIONS

The influence of phacotrabeculectomy on ocular surface is worse than that of trabeculectomy for the short run and is not distinct different for a long time.

Influence of Meibomian Gland Dysfunction and Friction-Related Disease on the Severity of Dry Eye

PURPOSE

To evaluate the effect of meibomian gland dysfunction (MGD) and friction-related disease (FRD) on the severity of dry eye disease (DED).

DESIGN

Cross-sectional observational study.

PARTICIPANTS

This study enrolled 449 patients with DED (63 men and 386 women; mean age, 62.6±15.7 years [range, 21-90 years]) for analysis.

METHODS

Subjective symptoms, the ocular surface, tear function, and the presence of MGD and FRD (superior limbic keratoconjunctivitis, conjunctivochalasis, and lid wiper epitheliopathy) were investigated.

MAIN OUTCOME MEASURES

Schirmer value, tear film breakup time (TBUT), and keratoconjunctival score.

RESULTS

We classified the participants into aqueous-deficient dry eye (ADDE; n = 231 [51.4%]) and short TBUT dry eye subtype (TBUT-DE; n = 109 [24.3%]) subgroups. The TBUT was shorter in patients with MGD than in those without MGD, whereas other ocular signs showed no difference (TBUT: MGD present, 1.97±1.02 seconds; MGD absent, 2.94±1.63 seconds [P < 0.001]; ADDE/MGD present, 1.94±1.08 seconds; ADDE/MGD absent, 2.77±1.61 seconds [P < 0.001]; short TBUT-DE/MGD present, 2.07±0.97 seconds; short TBUT-DE/MGD absent, 2.94±1.23 seconds [P = 0.01]). The ADDE patients with FRD showed a worse TBUT than ADDE patients without FRD (TBUT: ADDE/FRD present, 2.08±1.39 seconds; ADDE/FRD absent, 2.92±1.54 seconds; P < 0.001).

CONCLUSIONS

This study showed associations between MGD, FRD, or both and ocular signs in DED. In the presence of MGD, FRD, or both, TBUT was significantly shortened regardless of the dry eye status or subtype.

Relation of accommodative microfluctuation with dry eye symptoms in short tear break-up time dry eye

Purpose

To investigate accommodative microfluctuations (AMFs) and visual function in short tear break-up time (BUT)-type dry eye (DE) and non-DE subjects.

Methods

This prospective comparative study included 48 volunteers with DE symptoms (mean age 34.8 ± 5.5 years, age range 25–42 years) and 73 without DE symptoms (mean age 30.6 ± 4.7 years, age range 25–42 years). The eyes were divided into two groups: (1) DE group with DE symptoms and BUT ≤ 5 s and (2) non-DE group without DE symptoms and BUT > 5 s. We excluded eyes with Schirmer score ≤ 5 mm and positive keratoconjunctival epithelial damage. Tear evaluation, AMF, and functional visual acuity (VA) examinations were performed. AMF parameters included total high-frequency component (HFC), HFC with low accommodation for the task of staring into the distance (HFC1), and HFC with high accommodation for deskwork (HFC2). Functional VA parameters included starting VA, functional VA, visual maintenance ratio, and blink frequency.

Results

A total of 33 and 34 eyes were categorized in the DE and non-DE groups, respectively. Mean blink frequency and HFC1 values were significantly higher in the DE group than they were in the non-DE group.

Conclusions

DEs with symptoms showed abnormal AMF and visual function, which may be associated with DE symptoms.

Effectiveness of Combined Tear Film Therapy in Patients with Evaporative Dry Eye with Short Tear Film Breakup Time

PURPOSE

The aim of this study was to evaluate the effectiveness of combined tear film therapy targeted to aqueous, mucin, and lipid layers in patients with refractory evaporative dry eye (EDE) with short tear film breakup time (TBUT).

METHODS

The patients who had EDE with short TBUT and severe symptoms refractory to artificial tears were treated with hyaluronic acid (HA) 0.15% and diquafosol tetrasodium (DQS) 3% (Group 1), HA and carbomer-based lipid-containing eyedrops (Liposic EDO Gel, LPO) (Group 2), or HA, DQS, and LPO (Group 3). Ocular Surface Disease Index (OSDI) score, visual analog scale (VAS) symptom score, TBUT, Schirmer score, and corneal and conjunctival staining scores were evaluated, and noninvasive tear film breakup time (NIBUT) and tear meniscus height were measured using Keratograph^® 5 M before and 1 and 3 months after treatment.

RESULTS

OSDI scores, VAS scores, TBUT, and NIBUT were improved at 1 and 3 months after treatment in all groups (all P < 0.05). At each follow-up visit, the total OSDI, OSDI symptom, and all VAS scores were significantly lower in group 3 compared with groups 1 and 2 (all P < 0.05). In addition, TBUT and NIBUT were significantly higher in group 3 compared with groups 1 and 2 (all P < 0.05). No significant adverse effects were noted in the groups during treatment.

CONCLUSIONS

Mucin or lipid-targeting agents combined with aqueous supplements in patients with refractory EDE with short TBUT might improve subjective symptoms and TBUT. Of this, targeting whole tear film layers was most effective in improving ocular symptoms and tear film quality.

Diquafosol for Soft Contact Lens Dryness: Clinical Evaluation and Tear Analysis

PURPOSE

To evaluate the efficacy of topical application of 3% diquafosol tetrasodium solution for the treatment of soft contact lens (SCL) wearers with dryness. In addition to clinical tests and subjective symptoms, we assessed the fluorescence intensity of wheat germ agglutinin conjugate of fluorescein (F-WGA) used as a marker of membrane-associated mucins and sialic acid concentration in tear fluids as a marker of secreted mucins.

METHODS

Twelve SCL wearers with dryness symptoms were treated with diquafosol for 4 weeks. Clinical tests included the tear film break-up time (BUT), corneal and conjunctival fluorescein staining scores, and Schirmer values. Subjective symptoms were evaluated by the Dry Eye-Related Quality-of-Life Score (DEQS). Fluorescence intensities in the central cornea were measured by fluorophotometry at 5 minutes after a 5% F-WGA solution was applied to the eye. The tears collected by the Schirmer test strips were analyzed by high-performance liquid chromatography (HPLC), and the concentrations of sialic acid; total protein; and the four major tear proteins secretory IgA, lactoferrin, lipocalin-1, and lysozyme proteins were measured.

RESULTS

Comparing the results before and after diquafosol treatment, BUT (p < 0.01), kerato-conjunctival staining score (p < 0.05), corneal staining score (p < 0.05), and DEQS score (p < 0.01) showed statistically significant improvements. The F-WGA fluorescence intensities (p < 0.0001) significantly increased after treatment, whereas the concentrations of sialic acid and tear proteins remained unchanged.

CONCLUSIONS

Topical application of diquafosol solution to the SCL wearers with dryness improved biomarker of membrane-associated mucins, BUT, staining of cornea and conjunctiva, and subjective symptoms.

Classification of Fluorescein Breakup Patterns: A Novel Method of Differential Diagnosis for Dry Eye

PURPOSE

To investigate the relationship between fluorescein breakup patterns (FBUPs) and clinical manifestations in dry eye cases.

DESIGN

Cross-sectional study.

METHODS

In 106 eyes of 106 subjects (19 male, 87 female; mean age: 64.2 years), FBUPs were categorized into 1 of the following 5 break (B) types: area (AB, n = 19); spot (SB, n = 22); line (LB, n = 24); dimple (DB, n = 19); random (RB, n = 22 eyes); and dry eye-related symptoms using the visual analog scale (VAS, 100 mm = maximum), tear meniscus radius (TMR, mm), tear film lipid layer interference grade (IG) (grades 1-5; 1 = best) and spread grade (SG) (grades 1-4; 1 = best), tear film noninvasive breakup time (NIBUT, seconds), fluorescein breakup time (FBUT, seconds), corneal-epithelial damage (CED) score (15 points = maximum), ocular surface epithelial damage (OSED) score (9 points = maximum), and the Schirmer 1 test (ST1, mm) were examined and compared between each FBUP.

RESULTS

In each FBUP, eye dryness and fatigue were the severest symptoms. Characteristic symptoms were sensitivity to light, heavy eyelids, pain, foreign body sensation, difficulty opening the eye, and discharge for AB, heavy eyelids for SB, and foreign-body sensation for LB. Statistically significant differences were found in TMR (AB-SB, -DB, and -RB; LB-RB), IG (AB-all other FBUP; LB-SB and -DB), and SG (AB-all other FBUPs), FBUT (AB-LB, -DB, and -RB; SB-DB and -RB; LB-RB; DB-RB), and NIBUT (AB-all other FBUPs; SB-DB and-RB, and LB-RB), CED (AB-all other FBUPs; LB-SB, -DB, and -RB) and OSED (AB-SB, -LB, and -DB; LB-SB, -DB, and -RB), and ST1 (AB-SB, -DB, and -LB) (P < .05 in each comparison).

CONCLUSIONS

The 5 different FBUPs constituted different groups, reflecting different pathophysi-ologies.

TFOS DEWS II pathophysiology report

The TFOS DEWS II Pathophysiology Subcommittee reviewed the mechanisms involved in the initiation and perpetuation of dry eye disease. Its central mechanism is evaporative water loss leading to hyperosmolar tissue damage. Research in human disease and in animal models has shown that this, either directly or by inducing inflammation, causes a loss of both epithelial and goblet cells. The consequent decrease in surface wettability leads to early tear film breakup and amplifies hyperosmolarity via a Vicious Circle. Pain in dry eye is caused by tear hyperosmolarity, loss of lubrication, inflammatory mediators and neurosensory factors, while visual symptoms arise from tear and ocular surface irregularity. Increased friction targets damage to the lids and ocular surface, resulting in characteristic punctate epithelial keratitis, superior limbic keratoconjunctivitis, filamentary keratitis, lid parallel conjunctival folds, and lid wiper epitheliopathy. Hybrid dry eye disease, with features of both aqueous deficiency and increased evaporation, is common and efforts should be made to determine the relative contribution of each form to the total picture. To this end, practical methods are needed to measure tear evaporation in the clinic, and similarly, methods are needed to measure osmolarity at the tissue level across the ocular surface, to better determine the severity of dry eye. Areas for future research include the role of genetic mechanisms in non-Sjögren syndrome dry eye, the targeting of the terminal duct in meibomian gland disease and the influence of gaze dynamics and the closed eye state on tear stability and ocular surface inflammation.

TFOS DEWS II Tear Film Report

The members of the Tear Film Subcommittee reviewed the role of the tear film in dry eye disease (DED). The Subcommittee reviewed biophysical and biochemical aspects of tears and how these change in DED. Clinically, DED is characterized by loss of tear volume, more rapid breakup of the tear film and increased evaporation of tears from the ocular surface. The tear film is composed of many substances including lipids, proteins, mucins and electrolytes. All of these contribute to the integrity of the tear film but exactly how they interact is still an area of active research. Tear film osmolarity increases in DED. Changes to other components such as proteins and mucins can be used as biomarkers for DED. The Subcommittee recommended areas for future research to advance our understanding of the tear film and how this changes with DED. The final report was written after review by all Subcommittee members and the entire TFOS DEWS II membership.

Comparison of Short-Term Effects of Diquafosol and Rebamipide on Mucin 5AC Level on the Rabbit Ocular Surface

PURPOSE

To investigate the short-term effects of 2 new secretagogue eye drops for dry eye, 3% diquafosol tetrasodium ophthalmic solution (diquafosol) and 2% rebamipide ophthalmic suspension (rebamipide), on the concentration of mucin 5AC (MUC5AC) in rabbit tear fluid and conjunctival goblet cells.

METHODS

One dose of artificial tears, diquafosol or rebamipide, was instilled into 8 eyes of Japanese white rabbits. MUC5AC concentration in the tear fluid was examined using the enzyme-linked immunosorbent assay 15 min after instillation and compared with 8 untreated controls. Impression cytology was performed to measure the number of periodic acid Schiff (PAS)-positive cells and the ratio of the PAS-positive area using image analysis software. Statistical comparison was performed using ANOVA with post hoc analysis with the Tukey's test.

RESULTS

After 15 min, only diquafosol significantly (P ≤ 0.01) increased the MUC5AC level in the tear fluid. Although no drug affected the number of PAS-positive cells, the ratio of the PAS-positive area decreased significantly (P ≤ 0.01) only in the diquafosol group.

CONCLUSIONS

These data indicated that more PAS-positive MUC5AC was released into the tear fluid from the goblet cells by diquafosol than by rebamipide. There is a difference in the induction pattern of MUC5AC into the tears from the goblet cells between these eye drops.

New Perspectives on Dry Eye Definition and Diagnosis: A Consensus Report by the Asia Dry Eye Society

For the last 20 years, a great amount of evidence has accumulated through epidemiological studies that most of the dry eye disease encountered in daily life, especially in video display terminal (VDT) workers, involves short tear film breakup time (TFBUT) type dry eye, a category characterized by severe symptoms but minimal clinical signs other than short TFBUT. An unstable tear film also affects the visual function, possibly due to the increase of higher order aberrations. Based on the change in the understanding of the types, symptoms, and signs of dry eye disease, the Asia Dry Eye Society agreed to the following definition of dry eye: "Dry eye is a multifactorial disease characterized by unstable tear film causing a variety of symptoms and/or visual impairment, potentially accompanied by ocular surface damage." The definition stresses instability of the tear film as well as the importance of visual impairment, highlighting an essential role for TFBUT assessment. This paper discusses the concept of Tear Film Oriented Therapy (TFOT), which evolved from the definition of dry eye, emphasizing the importance of a stable tear film.

Assessment of the Tear Film Lipid Layer Thickness after Cataract Surgery

PURPOSE

To evaluate changes in the tear film lipid layer thickness (LLT) after cataract surgery and the effects of cataract surgery on dry eye syndrome (DES) and meibomian gland dysfunction (MGD).

METHODS

LLT measurements obtained using the LipiView interferometer, tear break-up time (TBUT) measurements, Schirmer's tests, Oxford staining scores, lid margin and meibomian gland findings, and the Ocular Surface Disease Index (OSDI) questionnaire scores were evaluated before and one and three months after cataract surgery.

RESULTS

Forty-three eyes (43 patients) were included. LLT was significantly thinner one month after surgery than at baseline (P = 0.004). TBUT was significantly shorter at both one (P < 0.001) and three (P < 0.001) months after surgery than at baseline. OSDI scores were significantly higher (P < 0.001) and the meibum quality was significantly poorer (P = 0.001) at one month after surgery than at baseline. TBUT was significantly and positively correlated with LLT (r = 0.29, P < 0.001), while the OSDI (r = -0.38, P < 0.001) and Oxford staining (r = -0.30, P = 0.001) scores and the meibum quality (r = -0.21, P = 0.01) were significantly and negatively correlated with LLT.

CONCLUSIONS

The tear film LLT was significantly thinner and DES and MGD parameters showed deterioration after cataract surgery. In addition, LLT was significantly correlated with DES and MGD parameters. These results suggest that clinicians should consider the tear film lipid layer while managing the exacerbation of DES after cataract surgery.

A pilot exome-wide association study of age-related cataract in Koreans

Age-related cataract (ARC) is the most common cause of visual impairment and blindness worldwide. A previous study reported that genetic factors could explain approximately 50% of the heritability of cataract. However, a genetic predisposition to ARC and the contributing factors have not yet been elucidated in the Korean population. In this study, we assessed the influence of genetic polymorphisms on the risk of ARC in Koreans, including 156 cataract cases and 138 healthy adults. We conducted an exome-wide association study using Illumina Human Exome-12v1.2 platform to screen 244,770 single nucleotide polymorphisms (SNPs). No SNPs reached exome-wide significance level of association (P < 1×10⁻⁶). B3GNT4 rs7136356 showed the most significant association with ARC (P = 6.54×10⁻⁵). Two loci (MUC16 and P2RY2) among the top 20 ARC-associated SNPs were recognized as probably linked to cataractogenesis. Functions of these genes were potentially related to regulating dehydration or homeostasis of the eyes, and showed a potential association with dry eye disease. This finding suggests that mucin- and dry eye disease-related genes may play a significant role in cataractogenesis. Our study provides insight into the genetic predisposition of ARC in Koreans. Additional studies with larger sample sizes are required to confirm the results of this study.

Prevalence of dry eye syndrome in residents of surgical specialties

Background

The aim of this study was to determine the prevalence and severity of dry eye syndrome in a group of Mexican residents of different surgical specialties.

Methods

A cross-sectional descriptive study where the residents were studied using the Ocular Surface Disease Index, together with diagnostic tests for dry eye syndrome, such as tear breakup time, Oxford Schema, Schirmer’s test I, and meibomian gland dysfunction testing. Statistical analyses were performed by Pearson’s chi-squared test for categorical variables and student’s t-test for quantitative variables. Any P value < 0.05 was considered statistically significant.

Results

One hundred and twenty-three residents were included (246 eyes); 90 (73 %) were male and 33 (27 %) were female. The mean age was 27.8 ± 2.1 years. A higher number of residents with dry eye syndrome was found in the cardiothoracic surgery (75 %) and otorhinolaryngology (71 %) specialties; 70 % of them reported ocular symptoms, with teardrop quality involvement in >50 % of them.

Conclusions

We found a prevalence of 56 % for mild-to-moderate/severe stages of the condition. Their presence in the operating room predisposes surgical residents to dry eye syndrome because of environmental conditions.

Effect of three months of soft contact lens wear on conjunctival cytology

BACKGROUND

The purpose of this study was to investigate the effect of three months of soft contact lens wear on conjunctival goblet cell density and epithelial cell morphology.

METHODS

This was a longitudinal clinical trial. Conjunctival impression cytology was performed on the superior palpebral conjunctiva in fifty-four eyes of twenty-seven neophyte contact lens wearers before and after three months of contact lens wear. Goblet cell density was determined by optical microscopy and epithelial cell morphology was classified according to the Tseng classification. Changes in goblet cell density as well as epithelial cell grading were determined. The effects of lens material and wearing modality on cytological changes were also investigated.

RESULTS

Goblet cell density reduced significantly by 85 ± 151 cells/mm(2) (p < 0.001) after three months of contact lens wear. Reduction in goblet cell density was associated with lens materials; it was higher in conventional hydrogel lenses in comparison to silicone-hydrogel lenses (p = 0.008). The highest reduction in goblet cell density was found with Nelfilcon A lens wear (p = 0.002) and the lowest with Comfilcon A lens wear (p = 0.414). There was no statistically significant difference in grading of epithelial metaplasia before and after three months of contact lens wear (p = 0.075). Age was not correlated with the reduction in goblet cell density (r = -0.196, p = 0.160) but it was associated with the change in epithelial cell morphology (p = 0.036).

CONCLUSION

Three months of soft contact lens wear statistically significantly reduced goblet cell density; however, no significant changes were found in the grading of epithelial metaplasia. Contact lenses with lower oxygen permeability, higher Young modulus and higher thickness highly affected the conjunctival cytology.

Efficacy and safety of topical diquafosol ophthalmic solution for treatment of dry eye: a systematic review of randomized clinical trials

PURPOSE

To evaluate the efficacy and safety of topical diquafosol ophthalmic solution for treatment of dry eye.

METHODS

Randomized clinical trials (RCTs) from MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were identified to evaluate the efficacy and safety of topical administration of diquafosol to patients with dry eyes. Data evaluation was based on endpoints including Schirmer test, tear film break-up time, ocular surface staining score, subjective symptom score, and adverse events.

RESULTS

A total of 8 RCTs involving 1516 patients were selected based on the prespecified criteria. Significant improvement of Schirmer test values and tear film break-up time were reported in 40% (2 of 5) and 80% (4 of 5) studies, respectively. Ocular surface staining scores significantly decreased in 100% (fluorescein corneal staining, 6 of 6; Rose Bengal corneal and conjunctival staining, 4 of 4) RCTs. Symptoms significantly improved in 75% (6 of 8) RCTs in patients with dry eyes. No severe adverse events were reported with the concentration of diquafosol from 0.5% to 5%. Heterogeneity in study design prevented meta-analysis from statistical integration and summarization.

CONCLUSIONS

Topical diquafosol seems to be a safe therapeutic option for the treatment of dry eye. The high variability of the selected RCTs compromised the strength of evidence and limits the determination of efficacy. However, the topical administration of diquafosol seems to be beneficial in improving the integrity of the epithelial cell layer of the ocular surface and mucin secretion in patients with dry eyes. This review indicates a need for standardized criteria and methods for evaluation to assess the efficacy of diquafosol in the future clinical trials.

Effects of Dry Eye Therapies on Environmentally Induced Ocular Surface Disease

PURPOSE

To evaluate the effectiveness of artificial tears and corticosteroids on mitigating the acute ocular surface response to low-humidity environments.

DESIGN

Single-group, crossover clinical trial.

METHODS

Twenty subjects with aqueous deficient dry eye were enrolled. Subjects meeting inclusion criteria at visit 1 were exposed to a baseline 90-minute low-humidity environment at visit 2. They then used artificial tears for 2 weeks prior to low-humidity exposure at visit 3, followed by 0.1% dexamethasone for 2 weeks prior to the final low-humidity exposure at visit 4. Outcome measures included corneal and conjunctival staining, blink rate, and irritation symptoms before and after each low-humidity exposure. Digital polymerase chain reaction (PCR) was performed to measure HLA-DR RNA transcripts in conjunctival cells taken by impression cytology at each visit.

RESULTS

There was significantly less corneal and conjunctival epitheliopathy after the low-humidity exposure at visit 4 compared to after the low-humidity exposure at visit 3 (P = .003). Subjects reported significantly less eye irritation during the low-humidity exposure after using the dexamethasone (visit 4) compared to artificial tears (visit 3) (P = .01). HLA-DR transcripts significantly decreased after the stress at visit 4 (post dexamethasone) compared to visit 2.

CONCLUSION

Our study demonstrates that corticosteroid eye drops mitigate the acute adverse effects of an experimental low-humidity challenge, likely owing to suppression of stress-activated inflammatory pathways. While extended use of corticosteroids is not indicated, other anti-inflammatory therapies with activity against stress-activated pathways may prove as effective.

Importance of tear film instability in dry eye disease in office workers using visual display terminals: the Osaka study

PURPOSE

To evaluate the relationship between subjective symptoms and clinical signs in dry eye disease (DED) in office workers using visual display terminals (VDTs).

DESIGN

Cross-sectional study.

METHODS

This study involved 672 Japanese young and middle-aged office workers who use VDTs. The subjects completed questionnaires designed to detect subjective symptoms and risk factors for DED. Dry eye tests, including tear film break-up time (TBUT), corneal-conjunctival staining with fluorescein and lissamine green, and the Schirmer test, were performed. Based on the Japanese diagnostic criteria for DED, the subjects were classified into 3 groups: definite DED, probable DED, and non-DED. Between each group, subjective symptoms and clinical signs were compared.

RESULTS

Of the 672 subjects, 561 (374 male, 187 female) completed the questionnaire (response rate: 83.5%). Definite DED was diagnosed in 65 subjects (11.6%), probable DED in 303 subjects (54.0%), and non-DED in 193 subjects (34.4%). The mean subjective symptom score was significantly less in subjects with probable DED (2.05 ± 0.42) and non-DED (1.63 ± 0.38) than in those with definite DED (2.19 ± 0.40) (P < .05 and P < .01, respectively). In the subjects with probable DED, a subgroup with positive subjective symptoms and abnormal TBUT (≤5 seconds) was categorized as short TBUT-type DED, and it was found that they had a higher subjective symptom score (2.09 ± 0.40), equivalent to that of those with definite DED (P = .269).

CONCLUSIONS

Despite no or minor epithelial damage, the severity of subjective symptoms was greater in short TBUT-type DED, most likely attributable to tear film instability. Thus, it might prove important to evaluate TBUT to successfully treat those patients.

Isolation of microRNA from conjunctival impression cytology

Impression cytology (IC) is an easy and safe technique that has been used in the past for harvesting epithelial cells from the cornea and conjunctiva for various applications including histology, immunohistology and molecular studies. Previous investigations have shown the usage of different types of membranes for the purpose of investigating pathophysiology and staging of diseases. This contributes to a better understanding of ocular surface conditions and helps to provide information for diagnosis, therapeutic options and prognosis. Recently, there has been a shift of focus in research towards understanding the contribution of microRNAs (miRs) to ocular disease. Thus far, impression cytology has been explored for measuring gene expression but not for quantifying miR expression. This study describes how miRs and mRNA can be isolated from conjunctival epithelial cells obtained by impression cytology and determines the optimum membrane and technique for this purpose. The IC technique was optimized using Biopore, Immobilon-P(SQ) and Millicell Hanging Cell Culture Insert membranes on healthy controls. miRs and mRNAs were isolated from the conjunctival epithelial cells (CEC) obtained and measured. Biopore membrane provided the optimum yield of miRs (38.8 ng/μL ± 10.8) and mRNA (155.3 ng/μL ± 20.1) as well as subjectively found to be best tolerated with minimum discomfort. Appreciable levels of miRs and mRNAs were detected from the CEC from healthy controls, confirming that it is possible to isolate miR and mRNA from CEC. Here, we give a detailed description of the application of conjunctival impression cytology to isolate miRs and the convenience of the technique by using the best membrane available. This method can be readily adopted in both clinical and laboratory settings. This technique will facilitate the measurement of miRs to improve our understanding of the pathogenesis of ocular surface conditions as well as potentially identifying novel therapeutic targets.

Effects of Systane(®) Balance on noninvasive tear film break-up time in patients with lipid-deficient dry eye

Purpose

To evaluate the ability of Systane^® Balance (SYSB) administered four times per day for 4 weeks to increase noninvasive tear film break-up time (NITFBUT) over baseline compared with a saline (SAL) control in patients with lipid-deficient dry eye (DE).

Patients and methods

Patients aged ≥18 years with DE and evidence of meibomian gland dysfunction (ie, abnormal gland expression and missing meibomian glands) were included in this randomized, parallel-group, controlled, investigator-masked comparison study. Patients were randomized to SYSB or SAL four times daily for 4 weeks. The primary efficacy variable was mean change in NITFBUT from baseline at week 4. Ocular surface staining, goblet cell density, and meibomian gland expression were also assessed. Safety assessments included adverse events (AEs), best-corrected visual acuity, and ocular signs.

Results

A total of 49 patients received study treatments (SYSB, n=25; SAL, n=24). Most patients were women (67.4%) and Caucasian (63.3%); mean ± standard deviation (SD) age was 44±19 years. DE characteristics at baseline were similar between groups. After 4 weeks of treatment, the mean ± SD NITFBUT increase from baseline was significantly greater with SYSB (2.83±0.74 seconds) compared with SAL (0.66±0.55 seconds; P<0.001, t-test). Improvements in conjunctival and corneal staining, percentage of patients with increased goblet cell density, and meibomian gland expression were also observed with 4 weeks of SYSB over SAL. No AEs were reported for either treatment group; best-corrected visual acuity and ocular signs remained stable or improved compared with baseline.

Conclusion

SYSB restored tear film stability, improved ocular surface healing, and improved meibomian gland functionality after 4 weeks of use in patients with lipid-deficient DE. No AEs were reported with either SYSB or SAL.

The Association between Dry Eye Disease and Physical Activity as well as Sedentary Behavior: Results from the Osaka Study

Purpose. To assess the association of dry eye disease (DED) with physical activity and sedentary behavior. Methods. The cross-sectional survey conducted included Japanese office workers who use visual display terminals (n = 672). DED was assessed according to the Japanese Dry Eye Diagnostic Criteria, and participants were categorized into "definite DED," "probable DED," or "non-DED" groups based on the results of DED examinations. Physical activity and sedentary behavior of participants were assessed using the International Physical Activity Questionnaire (IPAQ), and physical activity level was calculated in metabolic equivalent units per week (MET, min/week). Participants were classified as having a high, moderate, or low level of physical activity. Results. Participants with abnormal tear break-up time (BUT) (≤5 s) were involved in sedentary behavior for significantly longer duration than those with normal BUT (P = 0.035). Non-DED participants (14.5%) tended to have higher levels of physical activity than definite DED participants (2.5%). Participants with definite DED had significantly lower MET scores than those with non-DED (P = 0.025). Conclusions. Our findings suggest that a lower level of physical activity and sedentary behavior are associated with DED; however, longitudinal/intervention studies with large groups of participants are needed to validate these findings.

Effect of Korean Red Ginseng supplementation on dry eye syndrome in glaucoma patients - A randomized, double-blind, placebo-controlled study

BACKGROUND

Many patients with glaucoma have difficulty using antiglaucoma eye drops because of dry eye symptom. In this prospective, randomized, double-blind, placebo-controlled study, we evaluated the effect of Korean Red Ginseng on dry eye syndrome in patients with glaucoma treated with antiglaucoma eye drops.

METHODS

Forty-nine participants were allocated to the Korean Red Ginseng (3 g/day; n = 24) or placebo (n = 25) groups for 8 weeks. Tear film stability, fluorescein corneal staining, conjunctival hyperemia, tear production, grade of meibomian gland dysfunction, and dry eye questionnaire (Ocular Surface Disease Index) were evaluated at baseline and on completion of the treatment.

RESULTS

Almost all patients displayed dry eye symptoms and signs at baseline. After the 8-week intervention, Korean Red Ginseng supplementation significantly improved the tear film stability and total Ocular Surface Disease Index score, as compared to placebo (p < 0.01).

CONCLUSION

Korean Red Ginseng supplementation may provide an additional treatment option for dry eye and patients with glaucoma using antiglaucoma eye drops.

Rebamipide ophthalmic suspension for the treatment of dry eye syndrome: a critical appraisal

Rebamipide was initially developed and approved for use in treating gastric ulcers and lesions associated with gastritis. Discovery of its ability to increase gastric mucin led to investigations of its effect on ocular surface mucin and the subsequent development for use in dry eye patients. Investigations have confirmed that rebamipide increases corneal and conjunctival mucin-like substances along with improving corneal and conjunctival injury. Clinically, rebamipide ophthalmic suspensions can effectively treat tear deficiency and mucin-caused corneal epithelial damage, and can restore the microstructure responsible for tear stability. Topical rebamipide has also been shown to be effective in treating other ocular surface disorders such as lagophthalmos, lid wiper epitheliopathy, and persistent corneal erosion. Rebamipide's ability to modify epithelial cell function, improve tear stability, and suppress inflammation in the absence of any known major side effects suggest that it may be a beneficial first drug of choice for severe dry eye treatment and other ocular surface disorders. This review summarizes the history and development of this innovative dry eye treatment from its initial use as an effective stomach medication to its current use in the treatment of dry eye in Japan.