Association between systemic activity ındex and dry eye severity in patients with primary Sjögren syndrome

Submitted for publication: January 28, 2018 Accepted for publication: June 3, 2018 Funding: No specific financial support was available for this study. Disclosure of potential conflicts of interest: None of the authors have any potential conflicts of interest to disclose. Corresponding author: Dilay Ozek Dumlupinar Bulvari 364/B D.24 Ankara, Turkey E-mail: dilaytop@gmail.com Approved by the following research ethics committee: Ankara Numune Education and Research Hospital (# E-17-1531). ABSTRACT | Purpose: The aim of the present study was to compare the severity of ocular and systemic findings among patients with primary Sjögren syndrome. Methods: The study followed a prospective controlled design and comprised two groups; the test group included 58 eyes of 58 patients newly diagnosed with primary Sjögren syndrome with poor dry eye test findings and the control group included 45 right eyes of 45 healthy ageand sex-matched individuals. The ocular surface disease index score, tear osmolarity, Schirmer I test without anesthesia, fluorescein tear breakup time, and cornea-conjunctiva staining with lissamine green (van Bijsterveld scoring) were used to examine tear function in the patients via a complete ophthalmological examination. The results were graded and classified on the basis of a Dry Eye WorkShop report and results of the corneal and conjunctival staining test, Schirmer’s test, and fluorescein tear breakup time test. Discomfort, severity and frequency of symptoms, visual symptoms, conjunctival injection, eyelid-meibomian gland findings, and corneal-tear signs were interpreted. Disease activity was scored per the EULAR Sjögren’s syndrome disease activity index (ESSDAI) via systemic examination and laboratory evaluations, and the EULAR Sjögren’s syndrome patient-reported index (ESSPRI) assessed via a survey of patient responses. Results: Mean patient age was 48.15 ± 16.34 years in the primary Sjögren syndrome group and 44.06 ± 9.15 years in the control group. Mean fluorescein tear breakup time was 4.51 ± 2.89s in the primary Sjögren syndrome group and 10.20 ± 2.39 s in the control group. Mean Schirmer I test result was 3.51 ± 3.18 mm/5 min in the primary Sjögren syndrome group and 9.77±2.30 mm/5 min in the control group. Mean ocular surface disease index score was 18.56 ± 16.09 in the primary Sjögren syndrome group, and 19.92 ± 7.16 in the control group. Mean osmolarity was 306.48 ± 19.35 in the primary Sjögren syndrome group, and 292.54 ± 10.67 in the control group. Mean lissamine green staining score was 2.17 ± 2.76 in the primary Sjögren syndrome group, and 0.00 in the control group. Statistically significant differences were found berween the primary Sjögren syndrome group and control group in terms of fluorescein tear breakup time, Schirmer’s test, lissamine green staining, and osmolarity tests (p=0.036, p=0.041, p=0.001, and p=0.001 respectively). The Dry Eye WorkShop score was 2.15 ± 0.98, the EULAR Sjögren’s syndrome disease activity index score was 11.18 ± 4.05, and the EULAR Sjögren’s syndrome patient-reported index score was 5.20±2.63. When potential associations of the Dry Eye Workshop Study scores and osmolarity scores with the Eular Sjögren’s syndrome disease activity index scores were evaluated, the results were found to be statistically significant (p=0.001, p=0.001 respectively). Conclusion: The results showed an association between dry eye severity and systemic activity index in primary Sjögren syndrome patients.

ABSTRACT | Purpose: The aim of the present study was to compare the severity of ocular and systemic findings among patients with primary Sjögren syndrome.Methods: The study followed a prospective controlled design and comprised two groups; the test group included 58 eyes of 58 patients newly diagnosed with primary Sjögren syndrome with poor dry eye test findings and the control group included 45 right eyes of 45 healthy age-and sex-matched individuals.The ocular surface disease index score, tear osmolarity, Schirmer I test without anesthesia, fluorescein tear breakup time, and cornea-conjunctiva staining with lissamine green (van Bijsterveld scoring) were used to examine tear function in the patients via a complete ophthalmological examination.The results were graded and classified on the basis of a Dry Eye WorkShop report and results of the corneal and conjunctival staining test, Schirmer's test, and fluorescein tear breakup time test.Discomfort, severity and frequency of symptoms, visual symptoms, conjunctival injection, eyelid-meibomian gland findings, and corneal-tear signs were interpreted.Disease activity was scored per the EULAR Sjögren's syndrome disease activity index (ESSDAI) via systemic examination and laboratory evaluations, and the EULAR Sjögren's syndrome patient-reported index (ESSPRI) assessed via a survey of patient responses.Results: Mean patient age was 48.15 ± 16.34 years in the primary Sjögren syndrome group and 44.06 ± 9.15 years in the control group.Mean fluorescein tear breakup time was 4.51 ± 2.89s in the primary Sjögren syndrome group and 10.20 ± 2.39 s in the control group.Mean Schirmer I test result was 3.51 ± 3.18 mm/5 min in the primary Sjögren syndrome group and 9.77±2.30mm/5 min in the control group.
Mean ocular surface disease index score was 18.56 ± 16.09 in the primary Sjögren syndrome group, and 19.92 ± 7.16 in the control group.Mean osmolarity was 306.48 ± 19.35 in the primary Sjögren syndrome group, and 292.54 ± 10.67 in the control group.Mean lissamine green staining score was 2.17 ± 2.76 in the primary Sjögren syndrome group, and 0.00 in the control group.Statistically significant differences were found berween the primary Sjögren syndrome group and control group in terms of fluorescein tear breakup time, Schirmer's test, lissamine green staining, and osmolarity tests (p=0.036,p=0.041, p=0.001, and p=0.001 respectively).The Dry Eye WorkShop score was 2.15 ± 0.98, the EULAR Sjögren's syndrome disease activity index score was 11.18 ± 4.05, and the EULAR Sjögren's syndrome patient-reported index score was 5.20±2.63.When potential associations of the Dry Eye Workshop Study scores and osmolarity scores with the Eular Sjögren's syndrome disease activity index scores were evaluated, the results were found to be statistically significant (p=0.001,p=0.001 respectively).

Conclusion:
The results showed an association between dry eye severity and systemic activity index in primary Sjögren syndrome patients.

INTRODUCTION
Dry eye may cause potential damage to the ocular surface, and is associated with tear instability, visual problems, and discomfort, constituting a multifactorial disorder of the ocular surface.Tear osmolarity is increased and inflammation is observed on the ocular surface (1) .
Dry eye was described in a report in 2017 as "A multi factorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and accompanied by ocular symptoms in which tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neurosensory abnormalities play an etiological role" (2) .
Dry eye is a defect of the lacrimal functional unit that includes the lacrimal gland, the ocular surface (conjunctiva, cornea, and meibomian gland), the eyelid, and the sensory and motor nerves connecting them (3) .
This functional unit controls the main components of the tear film in a regulated form and responds to environmental, endocrinological, and cortical effects.Its general function is to maintain the integrity of the tear film, the transparency of the cornea, and the quality of the image reflected on the retina (3)(4)(5) .
Dry eye is examined in two parts etiopathologically, as evaporative and aqueous tear deficiency.Both are lacrimal functional unit disorders.Aqueous tear deficiency is a condition in which lacrimal secretion in the lacrimal glands is inadequate.When adequate tears cannot be produced, osmolarity and inflammation develop on the ocular surface (6) .Aqueous tear deficiency is categorised in two groups as Sjögren syndrome and Non-Sjögren syndrome.
Sjögren's syndrome is systemic disease in which lymphocyte infiltration into the exocrine glands damages the salivary gland and the lacrimal gland resulting in the development of dry eyes and dry mouth.This inflammatory process can also involve synovitis; vasculitis; and skin, lung, kidney, and neuronal systems (7)(8)(9) .Sjögren's syndrome aloneis referred to as primary Sjögren syndrome (PSS), and when accompanied by other autoimmune diseases such as systemic erythromatosis and rheumatoid arthritis, it is known as secondary Sjögren syndrome (SSS) (10)(11) .Auto-antibodies such as antinuclear antibody, Ro/SSA, La/SSB are detected in the serum of patients because PSS is an autoimmune disease (12) .Inflammatory mediators in the tear film and conjunctiva in PSS cause hyposecretion due to inflammation in the lacrimal gland and cause dry eye (13) .
In the present study, results of dry eye tests in PSS pa tients were classified based on a Dry Eye WorkShop (DEWS) report (14) using fluorescein breakup time (FBUT) test, Schirmer I test and lissamine green staining scores, and evaluation of discomfort, severity and frequency symptoms, visual symptoms, conjunctival injection, eyelid-meibomian gland findings, and corneal-tear signs; the EULAR Sjögren's syndrome disease activity index (ESSDAI) scoring system was also used to assess systemic disease activity.Considering the results of a comprehensive ESSDAI-correlated DEWS and literature searches, the present study is the first to evaluate both visual and systemic activity.We investigated whether or not ocular surface status was correlated with systemic activity of the PSS.

METHODS
The study was conducted in accordance with the principles of the Helsinki Declaration.Approval for the study was granted by the Ethics Committee of Ankara Numune Traning and Research Hospital.
The study followed a prospective, controlled design and comprised two groups; the test group included 58 eyes of 58 patients newly diagnosed with primary Sjögren syndrome with worsening dry eye test findings and the control group included 45 right eyes of 45 healthy age and gender-matched individuals with no systemic or eye diseases.The PSS group comprised 46 females and 12 males with a mean age of 48.15 ± 16.34 years.The control group comprised 35 females and 10 males with a mean age of 44.06 ± 9.15 years (p=0.213).
The disease was defined per the 2002 AECG (American-European Consensus Group) criteria for the diagnosis of PSS (15) .The 2010 ESSDAI index score was used to determine the systemic activity score of the disease (16) .This clinical index score assesses PSS in a standardized manner and classifies disease severity in 12 organ regions.ESSDAI is a physician-based assessment of systemic features and severity and includes kidney, synovitis, vasculitis, lung, skin, musculoskeletal system, and neurological evaluation.Scores <5 indicate low disease activity and scores ≥5 indicate high disease activity.Another simple index designed to measure PSS patient symptoms is the EULAR Sjögren's syndrome patient-reported index (ESSPRI) assessed via a survey of patient responses (17) .The survey used included three questions that assessed dryness, weakness, and pain in arms and legs during the previous two weeks.The patients marked the scale of the relevant complaint(s) from 0 to 10 and the total score was based on the average of three answers.
All evaluations of the ocular surface were done by one ophthalmologist (DO).The ocular surface disease index (OSDI) questionnaire, osmolarity, schirmer I test with no anesthesia, FBUT, and cornea-conjunctiva staining with lissamine green (van Bijsterveld scoring) were applied to evaluate tear function via a complete ophthalmological examination after PSS diagnosis and the results were graded based on the DEWS report.
Tear osmolarity was measured using the TearLab Osmolarity System (TearLab, San Diego, CA, USA) which automatically collects tears and provides test results.
The OSDI questionnaire consists of 12 items evaluating the symptoms of eye-related irritation and the effect on visual acuity.The Turkish translation of this questionnaire was done by a single physician (DO).The total OSDI score of each patient was calculated as follows; OSDI score = Total score in all answered questions × 100/Total number of questions answered × 4. A total score of ≥33 was considered to indicate severity (18,19) .
The Schirmer I test was done on the lower third of the lateral bulbar conjunctiva without topical anesthesia and the patients were asked to wait for five minutes and blink normally.The results were recorded in millimeters (mm).
The fluorescein breakup time (FBUT) test was done using a biomicroscope under cobalt blue light.A fluorescein strip (1% Biotech ® , India) was dropped onto the tear film of the patient, who was then told to blink once and not thereafter.The FBUT was recorded as the time in seconds from the blink until the appearance of the first break spot in the fluorescein under cobalt blue illumination.The test was repeated a total of three times and the average was considered the final result.Any break of the punctate epithelial defect was not evaluated.
Cornea-conjunctiva staining with lissamine green was done on the lower eyelid of the patients.A lissamine green strip (1.5 mg, Biotech ® , India) diluted with unpreserved artificial tears was placed in the lateral third of the bulbar conjunctiva.Biomicroscopy was done by a single physician (DO) to obtain the lissamine green staining score.The eye was divided into three sections comprising temporal, nasal conjunctival, and corneal sections, and each area was graded using the van Bijsterveld scoring system (0, no staining; 1, light staining; 2, moderate staining; 3, diffuse staining) (20) .The total stain was rated from 0 to 9.
The PSS diagnosis was assessed using the 2002 AECG findings regarding the diagnostic criteria for dry mouth and dry eye.Accordingly, salivary gland biopsy, sialography and/or scintigraphy, positive serology, and tests that define tear deficiency are recommended.The ESSDAI activity score is widely used, especially in the treatment plan.Using these criteria scored from 1-19, a score of <5 is evaluated as low, ≤13 as medium, and ≥14 as high activity (21) .The specificity of these criteria has been reported to be 95.2% and the sensitivity 89.5% (15) .In the present study, the ESSDAI and ESSPRI were evaluated by a single physician (AO) in the rheumatology department after PSS was first diagnosed per the AECA criteria.
Exclusion criteria were any previous ocular surgery, meibomian gland disease which may cause dry eye, blepharitis, use of topical drops in the previous six months, a systemic disease such as diabetes mellitus, hypertension, other rheumatologic disease, glaucoma, uveitis, or contact lens use.
All data were analyzed using the software Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, USA) 15.0 for Windows.Continuous variables were represented as mean± standard deviation and categorical variables as numbers and percentages.Independent samples t-test was used for the comparisons of the means of the patient and control groups.Pearson correlation analysis was performed to determine the association of ESSDAI and osmolarity scores with the other dry eye test parameters.A value of p<0.05 was accepted as statistically significant.

RESULTS
The dry eye test results and ESSDAI and ESSPRI evaluations of the patients are shown in table 1 and correlations of ESSDAI and osmolarity scores with dry eye test results of PSS patients are shown in table 2.
Lissamine green staining scores, osmolarity, schirmer I test scores, and FBUT scores in the PSS group were statistically significantly different from those in the control group (p=0.001,p=0.001, p=0.041, and p=0.036 respectively).

DISCUSSION
The ESSDAI was used to evaluate disease severity in PSS patients because of its recent extensive use in clinical practice.In a comprehensive review of the use of ESSDAI by Seror et al., the authors confirmed the validity of ESSDAI in most clinical studies and in ongoing clinical trials (22) .In an analysis of 195 patients by Risselada et al., the value of the ESSDAI in clinical practice was critically appraised for the first time.The ESSDAI scores were found to be low and stable in the general population and were recommended for their ability to capture disease activity in patients in whom individual changes may be present (23) .
The OSDI questionnaire addressing daily complaints of patients and their effect on visual acuity, eyelid examination, FBUT, Schirmer test, and cornea-conjunctiva staining with lissamine green or rose bengal are applied to evaluate dry eye in PSS patients.However, low specificity is a problem in these tests due to differences between examining physicians (1) .Occassionally, the patient symp-  toms may not be consistent with their findings.Therefore, tear osmolarity is considered a reliable diagnostic marker of dry eye disease (24)(25)(26)(27) .The TearLab Osmolarity system automatically collects tears and generates a numerical value.Several studies have indicated that dry eye severity and tear osmolarity are correlated (27)(28) .Bunya and et al. found that ocular osmolarity and Schirmer I test scores were correlated with dry eye symptoms in a study of PSS patients (29) .Kim et al. determined that mean osmolarity was 311.1 ± 16.4 mOsm/L and found a positive correlation with the OSDI score, a negative correlation with the Schirmer test scores, and no significant correlation with FBUT scores in PSS patients (30) .In the present study, osmolarity was determined to be 306.48± 19.35 mOsm/L and was found to be statistically significantly positively correlated with the lissamine green staining scores, DEWS scores, OSDI scores, and ESSDAI scores, and negatively correlated with the Schirmer I test scores and FBUT scores.There were differences between the PSS group and the control group in terms of the FBUT and Schirmer test scores but there were no differences in the OSDI test scores.It is also notable that the osmolarity, Schirmer test scores, FBUT scores, and lissamine green staining scores were higher in PSS eyes, and this emphasizes the reliability of these tests.
Although PSS may occur at any age, the mean age of onset is between 40-50 years and the female:male ratio is 9:1 (31,32) .In the present study, the female:male ratio was 3.8:1, which may be due to the study being conducted on patients recently diagnosed with PSS.
To the best of our knowledge, the present study is the first to demonstrate a correlation of ESSDAI with eye test findings.We found no correlation of ESSDAI with OSDI scores, FBUT scores, or Schirmer I test scores, and a positive correlation of ESSDAI with the lissamine green staining scores, osmolarity, and DEWS scores.Further, there were no correlations of ESSPRI or ESSDAI with osmolarity.

Table 1 .
Comparison of the dry eye and ESSDAI test scores in the PSS and control groups

Table 2 .
Correlations of ESSDAI and osmolarity scores with dry eye test scores in PSS patients *p <0.05, Pearson correlation analysis.