Cleaning effects of eyewashes on ocular surface symptoms caused by air pollution in a single-center, two-arm, nonrandomized trial in Indonesia: first report from Jakarta study.

PURPOSE: Air pollutants, such as Asian sand and particulate matter (PM) 2.5, have become a global concern for causing ocular inflammation and allergic symptoms. This study, as part of an international investigation, examined the effects of eyewashes for ocular damage caused by air pollution in Indonesia. METHODS: This was a single-center, patient- and-evaluator-blinded, parallel two-arm, nonrandomized trial. In Jakarta, Indonesia, 30 eyes of 15 car commuters and 30 eyes of 15 motorcycle commuters were recruited from healthy volunteers. After commuting to work, both eyes were washed with a commercial eyewash. Before and after eyewashing, eight items of ocular surface symptoms and four items of rhinitis subjective symptoms were scored using a modified Japanese Allergic Conjunctival Disease Quality-of-Life Questionnaire. RESULTS: Five of the 12 subjective symptom scores before eyewashing were higher in motorcycle commuters than in car commuters (p < 0.05). Motorcycle commuters showed improvement in the five symptom scores of "itchy eyes, foreign body sensation, eye mucus, dryness, and eye strain" after eyewashing compared to before eyewashing (p < 0.05). In all patients, sootlike particles and ocular mucus were found in the solutions collected after eyewashing. CONCLUSION: These findings indicate that eyewashing for ocular symptoms caused by airborne particles may be effective in removing foreign particles from the ocular surface and relieving subjective symptoms.

Eye Washing Downregulated Angiotensin-Converting Enzyme 2 in Conjunctival Tissue Samples from Smokers.

This study aimed to (1) determine whether the expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 is increased in tobacco smokers, which potentially increases their susceptibility to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and (2) assess whether eye rinsing can reduce susceptibility. This prospective study included 20 eyes of 10 smokers and 18 eyes of nine healthy non-smokers (control) for reverse-transcription polymerase chain reaction. This study also included 28 eyes of 14 smokers and 16 eyes of eight healthy non-smokers (control) for enzyme-linked immunosorbent assay. Tear and impression cytology samples were collected from the right eye of each patient. The left eye was then rinsed for 30 s, and after 5 min, the tear and impression cytology samples were collected in the same manner. The expression of the ACE2 gene was significantly higher in the conjunctiva of smokers (n = 17; median 3.07 copies/ng of total RNA) than in those of non-smokers (n = 17; median 1.92 copies/ng of total RNA, p = 0.003). Further, mRNA expression and protein levels of ACE2 were weakly correlated in smokers (r = 0.49). ACE2 protein levels in Schirmer's strip samples were significantly reduced from 5051 to 3202 pg/mL after eye washing (n = 10; p = 0.001). Ocular surface cells are susceptible to SARS-CoV-2 infection. Smoking may be a risk factor for SARS-CoV-2 infection, and eye rinsing may reduce the risk of infection.

Impact of Kayumidas© app on subjective symptoms and treatment adherence in allergic Rhinoconjunctivitis: Prospective Single-Arm interventional pilot study.

INTRODUCTION: In the spring of 2021, a physician-supervised application (app) "Kayumidas© - Itchy Eye Alert" was released for allergy sufferers, which implements a function to predict pollen dispersal status for each user based on weather forecasts and notify users of the results. This app provides push notifications of warning levels of itchiness and other symptoms, countermeasures, and the time to use medication. However, no evaluation has been conducted to determine whether the use of app improves compliance with treatment. This study aimed to verify whether the use of a smartphone app is effective in relieving the symptoms of allergic conjunctivitis and rhinitis and how it changes patients' eye drop behavior. METHODS: This was an investigator-initiated, observational, prospective cohort study that was conducted between February 2022 and May 2022. In 62 patients diagnosed with allergic conjunctivitis, the scores of nine subjective eye and nose symptoms (1-4) and eye itchiness (1-7) before and after using the app were compared using a questionnaire. The adherence scores for eye drops (1-4) were also investigated using a questionnaire. RESULTS: The scores for all five ocular subjective symptoms and all four nasal subjective symptoms improved significantly after app use (p < 0.01). Both itching scores (4.1 ± 1.1 vs. 1.6 ± 0.5, p < 0.01) and eye drop compliance scores (2.0 ± 0.7 vs. 3.9 ± 0.3, p < 0.01) improved significantly after app use. CONCLUSION: The use of the Kayumidas© app improved adherence to eye drops and the subjective symptoms of allergic conjunctivitis and rhinitis. Thus, app use effectively improves symptoms by changing behavior and improving self-care awareness regarding treatment in patients with allergic diseases.

Adhesion of Asian Dust Particles to Verofilcon a Soft Contact Lenses.

Purpose: Asian dust poses a serious global health hazard. Airborne particles adhering to contact lenses may cause substantial damage to the ocular surface. The recently released one-day disposable silicone hydrogel soft contact lens (SCL), the verofilcon A, has a smooth surface with SMARTSURFACE® technology, which is designed to prevent adhesion of protein components and foreign bodies. The purpose of this study was to verify the protective quality of verofilcon A SCL against adhesion of Asian dust particles to its surface. Methods: Verofilcon A and etafilcon A (control lens) SCLs were used (n=16 per group), and 0.2 mL of physiological saline containing 0.01 mg/mL of Asian dust particles was dropped on the surface of SCLs, allowed to stand for 1 hour, shaken for 1 minute, and rinsed three times with saline (after rinsing). In addition, the samples were agitated by a vortex mixer for 1 minute and rinsed three times with saline (after vortex). The number of Asian dust particles adhering to the SCLs and percentage of the surface area occupied by the Asian dust particles was determined before washing, after rinsing, and after vortexing. Results: The number of adherent Asian dust particles was lower on verofilcon A SCL (297 ± 116 after rinsing, and 5 ± 14 after vortexing) than on etafilcon A SCL (523 ± 212 after rinsing, p=0.003, and 378 ± 268 after vortexing, p<0.001). The Asian dust adhesion area was also lower on verofilcon A SCL (3.6 ± 2.3% after rinsing and 0.0 ± 0.1% after vortexing than on etafilcon A (10.2 ± 2.1% after rinsing, p=0.002, and 5.2 ± 3.0% after vortexing, p<0.001). Conclusion: These findings indicate that verofilcon A SCL has the property of low adhesion of Asian dust particles. Verofilcon A SCL can be recommended for SCL wearers during windy and Asian dust days.

Executive summary: Japanese guidelines for allergic conjunctival diseases 2021.

Allergic conjunctival disease (ACD) is an inflammatory disease of the conjunctiva that is mainly caused by type I hypersensitivity response to allergens and accompanied by subjective symptoms and other findings induced by antigens. ACD is classified as allergic conjunctivitis, atopic keratoconjunctivitis, vernal keratoconjunctivitis, and giant papillary conjunctivitis. This article summarizes the third edition of the Japanese guidelines for allergic conjunctival diseases published in 2021 and outlines the diagnosis, pathogenesis, and treatment of ACD. Since the introduction of immunosuppressive eye drops, the treatment strategies for severe ACDs have significantly changed. To clarify the recommended standard treatment protocols for ACD, the advantages and disadvantages of these treatments were assessed using clinical questions, with a focus on the use of steroids and immunosuppressive drugs. This knowledge will assist healthcare providers and patients in taking an active role in medical decision making.

Clinical Observation of Allergic Conjunctival Diseases with Portable and Recordable Slit-Lamp Device.

BACKGROUND: The incidence of allergic conjunctival diseases (ACDs) is gradually increasing worldwide. Both ophthalmologists and non-ophthalmologists prescribe eye drops to treat ACDs; however, there are many cases which are treated without sufficient examination and diagnosis of the eyes. We have invented a portable, recordable, and smartphone-attachable slit-lamp device-Smart Eye Camera (SEC). The purpose of this study was to compare the diagnostic abilities of ACDs between the SEC and the conventional, non-portable slit-lamp microscope. METHODS: This prospective observational study included 32 eyes of 17 Japanese patients (mean age: 21.5 ± 14.8 years; range: 11-51 years; female: 5). The severity of 10 objective signs in the palpebral conjunctiva, bulbar conjunctiva, limbus, and cornea were scored on a grading scale of 0 to 4 (0 = normal; 1+ = mild; 2+ = moderate; 3+ = severe), respectively. First, the conventional slit-lamp microscope was used to examine the grade of the ACDs. Second, another ophthalmologist filmed the eyes using the SEC and two other ophthalmologists evaluated the grades on another day. The correlation and inter-rater reproducibility in total scores among the two devices were determined. RESULTS: Total scores of clinical signs, evaluated by the two approaches, correlated significantly (both eyes: r = 0.918 (95% CI: 0.839 to 0.959; p < 0.001)), with substantial inter-rater agreement (weighted κ value = 0.631 (95% CI: 0.601 to 0.661; p < 0.001)). CONCLUSIONS: The SEC is as reliable as the conventional non-portable slit-lamp microscope for assessing ACDs.

Adhesion of Pollen Particles to Daily Disposable Soft Contact Lenses.

PURPOSE: Pollen and proteins attached to soft contact lenses (SCLs) exacerbate allergic conjunctivitis. The material of SCLs may affect the pollen adhesion to the SCLs. The factors associated with the number of pollen particles that are adherent to daily disposable SCL were investigated. METHODS: Pollen particles were experimentally exposed to the contact lens surface of 12 types of SCLs for 1 hour, and the SCLs were washed and rinsed with a physiological saline (n=10 for each SCL type). A total of 120 contact lenses were used in this study. The pollen particles attached to the SCL were observed and photographed under a microscope. The influence of the materials of the SCLs on the degree of pollen adhesion were investigated. RESULTS: The number of residual pollen particles attached to SCLs was in the range from 0-293/area of 200×200 µm. Percentage of pollen adhesion area of the surface of the SCL was in the range from 0.01% to 3.25%. There were significant differences in both the number and adhesion area of pollen particles among the 12 types of SCLs tested (P<0.0001 and P<0.0001, respectively). The number of pollen particles adhered to SCLs was significantly higher in colored SCLs than clear SCLs (unpaired t-test, p<0.001). The portion of pollen adhesion area was the lowest in the silicone hydrogel SCLs made with delefilcon-A (0.01 ± 0.02%). CONCLUSION: Pollen adhesion in daily disposable SCLs depends on the characteristics and materials of the SCLs and was high in colored SCLs and lowest in delefilcon-A silicone hydrogel SCL. These results suggest that colored SCLs are not preferred during pollen season.

Long-term outcomes of 0.1% tacrolimus eye drops in eyes with severe allergic conjunctival diseases.

BACKGROUND: Because atopic dermatitis does not heal completely, associated severe atopic keratoconjunctivitis (AKC) and vernal keratoconjunctivitis (VKC) often require long-term treatment. This study aims to evaluate the long-term outcomes of using 0.1% tacrolimus eye drops to treat these severe allergic conjunctival diseases. METHODS: Two-hundred-and-seventy eyes of 135 patients diagnosed with AKC or VKC from April 2004 to April 2014 were screened retrospectively. Patient demographics and objective signs were extracted from the electronic medical records. The severity of 10 objective signs, related to the palpebral and bulbar conjunctiva, limbus, and cornea, and intraocular pressure (IOP) were observed at baseline, at 2 weeks, 1, 2, 3, 6, and 12 months after starting treatment, and every 1 year thereafter (average use period: 8.4 ± 2.9 years). Safety was evaluated based on the incidence and severity of adverse events. RESULTS: 12 patients (AKC; 7 cases, VKC; 5 cases) who were treated with 0.1% tacrolimus eye drops were enrolled in this study. The total score of clinical signs significantly decreased after 2 weeks and remained effective thereafter. Tacrolimus eye drops elicited a statistically significant difference in the mean total clinical scores and IOP over the course of treatment (P < 0.001). Elevated IOP was observed in 2 cases and corneal infection in 1 case; these effects were completely controlled with medication. CONCLUSIONS: Topical tacrolimus may provide effective and long-term improvement in clinical signs of severe AKC and VKC cases that refractory to standard conventional treatment. TRIAL REGISTRATION: University Hospital Medical Information Network (UMIN) 000034460.

Japanese guidelines for allergic conjunctival diseases 2020.

The definition, classification, pathogenesis, test methods, clinical findings, criteria for diagnosis, and therapies of allergic conjunctival disease are summarized based on the Guidelines for Clinical Management of Allergic Conjunctival Disease 2019. Allergic conjunctival disease is defined as "a conjunctival inflammatory disease associated with a Type I allergy accompanied by some subjective or objective symptoms." Allergic conjunctival disease is classified into allergic conjunctivitis, atopic keratoconjunctivitis, vernal keratoconjunctivitis, and giant papillary conjunctivitis. Representative subjective symptoms include ocular itching, hyperemia, and lacrimation, whereas objective symptoms include conjunctival hyperemia, swelling, folliculosis, and papillae. Patients with vernal keratoconjunctivitis, which is characterized by conjunctival proliferative changes called giant papilla accompanied by varying extents of corneal lesion, such as corneal erosion and shield ulcer, complain of foreign body sensation, ocular pain, and photophobia. In the diagnosis of allergic conjunctival diseases, it is required that type I allergic diathesis is present, along with subjective and objective symptoms accompanying allergic inflammation. The diagnosis is ensured by proving a type I allergic reaction in the conjunctiva. Given that the first-line drug for the treatment of allergic conjunctival disease is an antiallergic eye drop, a steroid eye drop will be selected in accordance with the severity. In the treatment of vernal keratoconjunctivitis, an immunosuppressive eye drop will be concomitantly used with the abovementioned drugs.

Epidemiological aspects of allergic conjunctivitis.

The prevalence of ocular allergies has been increasing worldwide for the past several decades. The geographical distribution and hot spots of rhinoconjunctivitis have been documented in a global survey by the International Study of Asthma and Allergies in Childhood (ISAAC). ISAAC indicated that Africa, Latin America, and Japan were notable for their high prevalence of rhinoconjunctivitis. The outcomes of follow-up studies of regional differences and the characteristics of allergic conjunctivitis are summarized in this review. Currently, comorbid diseases and socioeconomic and environmental factors, including climate and air pollution, are proposed to contribute to the regional differences in the prevalence of allergic conjunctivitis. Of them, rhinitis has been shown repeatedly to be significantly associated with allergic conjunctivitis. Their mechanistic aspects on association with the prevalence of systemic allergic diseases have been reviewed by examining the birth cohort or in vitro analyses. A vision threatening form of ocular allergy, vernal keratoconjunctivitis, is prevalent in the African countries and Japan. Of the proposed associated factors, air pollution was shown to contribute not only to aggravating the symptoms but also to the increase in the incidence of its severe forms. Its mechanistic aspects are discussed in this review in the context of comorbid diseases.

Combination of Two Rapid Ophthalmic Test Kits for Improved Diagnosis in Cases of Severe Binocular Conjunctivitis.

INTRODUCTION: Diagnosis of conjunctivitis can be sometimes difficult, especially in cases of severe conjunctivitis and those involving both eyes. In this study, we performed commercial tests for adenovirus (Capilia Adeno Eye®) and total tear IgE (Allerwatch®) in a single visit in patients with bilateral conjunctivitis to examine if, and by how much, the combination of these two tests would improve the diagnostic accuracy of conjunctivitis. METHODS: The study included sixty patients with relatively severe conjunctivitis in both eyes within a week of consulting our clinic and who had no previous treatment. Capilia Adeno Eye® and Allerwatch® tests were performed. RESULTS: A significantly higher number of cases (55/60) were diagnosed when both tests were evaluated than with either test (Capilia Adeno Eye® (12/60; p < 0.001) or Allerwatch® (44/60; p < 0.005)) alone. The positivity rate of Allerwatch® was significantly higher than that of Capilia Adeno Eye® (p < 0.001). The diagnosis rate of atopic keratoconjunctivitis was 100% in patients with allergic conjunctivitis, but there was no significant difference in positivity compared with other types of allergic conjunctivitis. CONCLUSIONS: Testing patients with both Capilia Adeno Eye® and Allerwatch® improves the diagnostic accuracy for conjunctivitis and can diagnose more than 90% of cases. Detection of adenovirus antigen and IgE in tears, using these simple and rapid methods, will be useful for early diagnosis and prevention of adenoviral conjunctivitis.

Effects of Docosahexaenoic Acid on Chemokine Expression in Human Conjunctival Fibroblasts.

Purpose: We assessed the production of chemokines by human conjunctival fibroblasts in response to inflammation and the effects of omega (ω)-3 fatty acids on chemokine expression.Methods: Primary cultures of human conjunctival fibroblasts were incubated with interleukin-4 (IL-4) and tumor necrosis factor-alpha (TNF-α). The expression of eotaxin-1 and RANTES in response to pretreatment with docosahexaenoic acid (DHA) was investigated. Moreover, western blotting was used to evaluate the effects of DHA on the activation of nuclear factor (NF)-κB and signal transducer and activator of transcription 6 (STAT6).Results: The expression of eotaxin-1 mRNA was significantly suppressed by pretreatment with DHA with IL-4 and TNF-α costimulation. RANTES expression was similarly suppressed, but the difference was not significant. The secretion of eotaxin-1 and RANTES was significantly lower in DHA-pretreated cells than in vehicle-treated cells. Western blotting for NF-κB and STAT6 showed that these proteins were downregulated in the DHA pretreatment group compared with those in the vehicle control group.Conclusion: The results of this study suggested that DHA could have applications in the management of allergic inflammation.

The Effect of Cytokine-Stimulation and Pharmacologic Intervention on PGE2 Production in Primary Human Conjunctival and Corneal Cells.

We studied the production of PGE2 by human conjunctival and corneal cells in response to inflammation, and reduction of inflammation with non-steroidal anti-inflammatory drugs. Primary cultures of human conjunctival epithelial cells, fibroblasts, corneal epithelial cells, and keratocytes were incubated with IL-4 and TNF-α. PGE2 and COX-2 levels were analyzed. Effects of anti-inflammatory and anti-immune drugs on PGE2 production were also investigated. IL-4 and TNF-α induced the generation of PGE2 and COX-2 in conjunctival and corneal cells. Epithelial PGE2 production was significantly lower than in keratocytes and fibroblasts, which was down-regulated by aspirin. IL-4 and TNF-α enhanced the inflammatory response via prostaglandin production which contributed to ocular surface inflammation. Prostaglandin production was higher in stromal cells than epithelial cells. These results suggest that the epithelial barrier disruption may contribute to ocular allergic inflammation by the PGE2 production from stromal cells. Moreover, NSAIDs were effective in suppressing PGE2 production in our experiment.

Air pollution significantly associated with severe ocular allergic inflammatory diseases.

Ambient air pollution is a well-recognized risk for various diseases including asthma and heart diseases. However, it remains unclear whether air pollution may also be a risk of ocular allergic diseases. Using a web-based, nation-wide, cross-sectional study design, we examined whether the level of ambient air pollution is significantly associated with the prevalence of ocular allergic diseases. A web-based questionnaire was posted to invite the participants who are members of the Japan Ophthalmologist Association and their family members. The answers from 3004 respondents were used to determine whether there were significant associations between the level of the pollutants and the prevalence of ocular allergic diseases. The study period was between March to May 2017. The data of the air pollutants during 2012 to 2016 were obtained from the National Institute for Environmental Studies. The prevalence of allergic diseases was calculated by post stratification and examined for significant associations with the level of pollutants using multiple logistic regression analyses. The prevalence of seasonal allergic conjunctivitis, perennial allergic conjunctivitis, atopic keratoconjunctivitis (AKC), and vernal keratoconjunctivitis (VKC) in Japan was 45.4%, 14.0%, 5.3%, and 1.2%, respectively. The high prevalence of the severe forms of allergic conjunctivitis, including AKC and VKC, were significantly associated with the levels of the air pollutants. The prevalence of AKC was significantly associated with the levels of NO2 with an odds ratio (OR) of 1.23 (per quintile). The prevalence of VKC was significantly associated with the levels of NOx and PM10 with ORs of 1.72 and 1.54 respectively. The significant associations between the prevalence of AKC and VKC and the levels of air pollutants indicate that clinicians need to be aware that air pollutants may pose serious risks of vision threatening severe ocular allergy.

The efficacy of 0.1% tacrolimus ophthalmic suspension in the treatment of severe atopic keratoconjunctivitis.

BACKGROUND: Severe atopic keratoconjunctivitis (AKC) is a relatively rare disease, and some cases are refractory to conventional steroid treatment. OBJECTIVE: To examine the efficacy of 0.1% tacrolimus ophthalmic suspension in treating severe AKC during a 1-year follow-up. METHODS: This was a single-center, retrospective clinical study. Sixty eyes from 30 patients with severe AKC who were treated with 0.1% tacrolimus ophthalmic suspension 4 times per day, were included. The mean age of the patients was 21.5 ± 13.7 years. The severity of objective signs was observed at baseline (before treatment), at 2 weeks, and at 1, 2, 3, 6, and 12 months after treatment initiation. Ten objective signs of palpebral conjunctiva, bulbar conjunctiva, limbus, and cornea were assessed using 4 grades (0 = normal; 1+ = mild; 2+ = moderate; 3+ = severe). Safety was assessed based on the incidence and the severity of adverse events. RESULTS: The total score of the 10 clinical signs significantly decreased from baseline 2 weeks after initiating tacrolimus eye drop treatment, except at 2 months. The mean total score of clinical signs was 13.6 ± 6.6 at the beginning of treatment, and decreased to 5.4 ± 4.8 12 months after initiation. Treatment was gradually tapered, with increasing intervals between applications. Additional medications were required to provide relief in 18 patients during follow-up. No patient discontinued treatment due to adverse drug effects. Herpes keratitis was observed in 3 cases during follow-up. However, these cases were completely controlled. CONCLUSION: The 0.1% tacrolimus ophthalmic suspension is effective for the treatment of severe AKC refractory to standard conventional treatments throughout a full year.

A Prospective, Randomized Trial of Two Mucin Secretogogues for the Treatment of Dry Eye Syndrome in Office Workers.

The purpose of the study was to compare the two mucin secretogogues, diquafosol (DQS) and rebamipide (RBM), for the treatment of dry eye syndrome (DES) in office workers. Dry eye patients using computers for >4 h/day were randomly assigned treatment with either DQS or RBM. Main outcomes measures included changes in tear film break-up time (TBUT) and subjective symptoms assessed by the Dry Eye-Related Quality of Life Score (DEQS). The subjects had scheduled examinations at 0 and 4 weeks, and the examinations at 2 and 8 weeks were optional. Changes in keratoconjunctival fluorescein score and a patient satisfaction questionnaire were also recorded. Both groups showed significant improvements in the DEQS scores at 2, 4, and 8 weeks following the initiation of the study. Both groups showed significant increases in the TBUT at 2 and 4 weeks. No significant difference was found between the DQS and RBM groups at any time periods. Patients reported more comfort with the use of DQS compared with the use of RBM. No local or systemic side effects were noted. The results of the present study indicated that both DQS and RBM were effective for the treatment of DES in office workers.

Japanese guidelines for allergic conjunctival diseases 2017.

The definition, classification, pathogenesis, test methods, clinical findings, criteria for diagnosis, and therapies of allergic conjunctival disease are summarized based on the Guidelines for Clinical Management of Allergic Conjunctival Disease (Second Edition) revised in 2010. Allergic conjunctival disease is defined as "a conjunctival inflammatory disease associated with a Type I allergy accompanied by some subjective or objective symptoms." Allergic conjunctival disease is classified into allergic conjunctivitis, atopic keratoconjunctivitis, vernal keratoconjunctivitis, and giant papillary conjunctivitis. Representative subjective symptoms include ocular itching, hyperemia, and lacrimation, whereas objective symptoms include conjunctival hyperemia, swelling, folliculosis, and papillae. Patients with vernal keratoconjunctivitis, which is characterized by conjunctival proliferative changes called giant papilla accompanied by varying extents of corneal lesion, such as corneal erosion and shield ulcer, complain of foreign body sensation, ocular pain, and photophobia. In the diagnosis of allergic conjunctival diseases, it is required that type I allergic diathesis is present, along with subjective and objective symptoms accompanying allergic inflammation. The diagnosis is ensured by proving a type I allergic reaction in the conjunctiva. Given that the first-line drug for the treatment of allergic conjunctival disease is an antiallergic eye drop, a steroid eye drop will be selected in accordance with the severity. In the treatment of vernal keratoconjunctivitis, an immunosuppressive eye drop will be concomitantly used with the abovementioned drugs.

The usefulness of measuring tear periostin for the diagnosis and management of ocular allergic diseases.

BACKGROUND: Chronic ocular allergic diseases such as vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC) are accompanied by serious comorbidities; however, the underlying pathogenesis remains obscure. Furthermore, diagnosing conjunctival lesions in patients with atopic dermatitis and estimating the severity in AKC are important for the treatment of ocular allergic diseases. OBJECTIVE: We addressed whether periostin, a novel mediator and biomarker in allergic inflammation, is involved in the pathogenesis of ocular allergic diseases and whether periostin can be a biomarker for these diseases. METHODS: We investigated tear periostin in patients with seasonal allergic conjunctivitis (SAC), VKC, and AKC and allergic patients without conjunctivitis and compared it with tear IL-13 and serum periostin. Furthermore, in patients with AKC, we measured tear periostin before and after topical treatment with tacrolimus. RESULTS: Tears from patients with ocular allergic disease showed significantly high periostin levels than did tears from allergic patients without conjunctivitis and from patients with AKC, VKC, and SAC in descending order. Tear periostin was associated with serious comorbidities such as large papilla formation and corneal damage in AKC, although both tear IL-13 and serum periostin had little to no such abilities. Furthermore, after topical tacrolimus treatment, tear periostin tended to decrease in most patients with AKC along with their clinical improvement. CONCLUSIONS: Periostin produced in conjunctival tissues stimulated by IL-13 may contribute to the pathogenesis of ocular allergic diseases. Furthermore, tear periostin can be potentially applied as a biomarker to diagnose conjunctivitis in allergic patients and to evaluate disease severity as well as the efficacy of treatments in AKC.