Modification of the tear function index and its use in the diagnosis of Sjögren's syndrome

Efficacy of hydroxypropyl-guar drops in improving tear film index and ocular surface dynamics using two treatment methods under a controlled desiccating environment

AIM

This study aimed to assess the efficacy of hp-guar eye drops on tear film index and ocular surface dynamics under desiccating conditions using protection and relief treatment modalities.

METHODOLOGY

The 12 normal, non-dry eye participants were subjected to adverse environmental conditions using a Controlled Environment Chamber (CEC) where the relative humidity (RH) was 5% and the ambient temperature was 21 °C. The participants were screened for ocular symptoms, tear osmolarity, ocular surface temperature (OST), tear production using the Ocular Surface Disease Index questionnaire (OSDI), OcuSense TearLab Osmometer, FLIR System ThermaCAM P620, and Schirmer strips. Tear production was calculated by the Tear Function Index test (TFI).

RESULTS

The mean tear film osmolarity decreased significantly from 296 mOsm/L at 40% RH to 285 mOsm/L at 5% RH (p = 0.01). Conflicting responses were seen for osmolarity in protection and relief. Mean tear osmolarity was significantly higher in the protection method in comparison to the relief method (p = 0.005). The mean TFI increased from 557 at 40% to 854 at 5% (p = 0.02). A significant increase in TFI was observed in the relief method in comparison with both 40% (p = 0.001) and 5% (p = 0.04). In the relief method, the mean TFI score went up to 1139 when hp-guar was installed. A significant improvement in ocular comfort was experienced in both the protection (p = 0.041) and relief (p = 0.010) methods at 5% RH. The instillation of hp-guar drops in the relief method resulted in a significant reduction in OST. The mean OST dropped to 33.01 ºC, significantly lower than the recorded OST for both normal (p = 0.040) and dry (p = 0.014) environmental conditions.

CONCLUSION

Hp-guar drops significantly improve tear film parameters under a desiccating environment, however, tear film parameters respond differently to the management modalities. In the protection method, tear film osmolarity was protected against a dry environment, while in the relief mode, an improvement in tear production and a decrease in ocular surface temperature were seen. Hp-guar performance could be maximized for the management of exposure to adverse environments by using a treatment protocol that targets the most affected parameters in each group of patients. Using CEC has the potential to provide researchers with a readily available method to evaluate the efficiency of tear supplementation.

Ophthalmological Approach for the Diagnosis of Dry Eye Disease in Patients with Sjögren's Syndrome

Dry eye has two basic subdivisions: aqueous deficient dry eye (ADDE), with SS a major cause; and evaporative dry eye (EDE), due to either intrinsic or extrinsic factors. SS is a chronic inflammatory disorder defined by dysfunction of the exocrine glands leading to dry eye and dry mouth. The objective of this article was to carry out a systematic and critical review of several scientific publications on dry eye disease, with the aim of providing general recommendations to distinguish dry eye and its different variants in patients with SS, during the period 1979 to 2020, using search engines for articles indexed in Scopus, Latindex, Scielo, Clinical Trials, Medline, Embase, and Cochrane, allowing the analysis of 132 articles published in indexed journals on the subject of dry eye disease and SS, evidencing its conceptualization, prevalence, risk factors, etiopathogenesis, clinical manifestations, diagnosis, and treatment.

In vitro validation of the tear matrix metalloproteinase 9 in-situ immunoassay

We aimed to validate a tear MMP-9 in-situ immunoassay (InflammaDry) and to identify factors that could affect results or interpretation. Three factors were examined: sample concentration, volume, and time. Recombinant human (rh) MMP-9 (10 or 20 μl; 0, 12.5, 25, 50, 100, 200, 500, and 1,000 ng/ml) was applied to the kit and the detection limit and assay reproducibility were examined. At a rhMMP-9 volume of 10 μl (≥ 50 ng/ml), all positive results were identified by densitometry at 10 and 20 min; however, after 20 min, more than half of the nine ophthalmologists interpreted a positive result. At a rhMMP-9 volume of 20 μl (≥ 25 ng/ml), ophthalmologists and densitometry identified almost all test lines at 10 and 20 min. At 10 μl, densitometry showed a linear dose–response pattern. At 20 μl, densitometry showed a linear dose–response pattern at concentrations up to 500 ng/ml; however, full saturation was achieved at concentrations ≥ 500 ng/ml. When the same amount of rhMMP-9 was applied, the density result increased significantly upon doubling of the solvent volume (i.e., by adding the same volume of PBS to a sample). InflammaDry showed a high inter- and intra-assay coefficient of variation at 10 min (28.4% and 24.7%, respectively). The results of the MMP-9 in-situ immunoassay varied significantly depending on sample volume. Therefore, when interpreting the results, careful attention must be paid to tear volume.

The Potential Role for Early Biomarker Testing as Part of a Modern, Multidisciplinary Approach to Sjögren's Syndrome Diagnosis

Sjögren's syndrome (SS) is a chronic and progressive multisystem autoimmune disease typically managed by rheumatologists. Diagnostic delays are common, due in large part to the non-specific and variable nature of SS symptoms and the slow progression of disease. The hallmark characteristics of SS are dry eye and dry mouth, but there are a broad range of other possible symptoms such as joint and muscle pain, skin rashes, chronic dry cough, vaginal dryness, extremity numbness or tingling, and disabling fatigue. Given that dry eye and dry mouth are typically the earliest presenting complaints, eye care clinicians and dental professionals are often the first point of medical contact and can provide critical collaboration with rheumatologists to facilitate both timely diagnosis and ongoing care of patients with SS. Current diagnostic criteria advocated by the American College of Rheumatology are predicated on the presence of signs/symptoms suggestive of SS along with at least two objective factors such as traditional biomarker positivity, salivary gland biopsy findings, and/or presence of keratoconjunctivitis sicca. Traditional biomarkers for SS include the autoantibodies anti-Sjögren's syndrome-related antigen A (SS-A/Ro), anti-Sjögren's syndrome-related antigen B (SS-B/La), antinuclear antibody (ANA) titers, and rheumatoid factor (RF). While diagnostically useful, these biomarkers have low specificity for SS and are not always positive, especially in early cases of SS. Several newly-identified biomarkers for SS include autoantibodies to proteins specific to the salivary and lacrimal glands [SP-1 (salivary gland protein-1), PSP (parotid secretory protein), CA-6 (carbonic anhydrase VI)]. Data suggest that these novel biomarkers may appear earlier in the course of disease and are often identified in cases that test negative to traditional biomarkers. The Sjö^® test is a commercially available diagnostic panel that incorporates testing for traditional SS biomarkers (anti-SS-A/Ro, anti-SS-B/La, ANA, and RF), as well as three novel, proprietary early biomarkers (antibodies to SP-1, PSP, and CA-6) which provide greater sensitivity and specificity than traditional biomarker testing alone. Timely diagnosis of SS requires appropriate clinical vigilance for potential SS symptoms, referral and collaborative communication among rheumatology, ophthalmology, and oral care professions, and proactive differential work-up that includes both physical and laboratory evaluations.

Ocular Surface Changes With Sofosbuvir in Egyptian Patients With Hepatitis C Virus Infection

PURPOSE

To evaluate the effect of oral sofosbuvir on the ocular surface of Egyptian patients with chronic hepatitis C virus infection.

METHODS

This prospective randomized comparative study was performed on 300 eyes undergoing sofosbuvir therapy with peginterferon and ribavirin and on 300 eyes undergoing treatment with only peginterferon and ribavirin. Patients were evaluated for dry eye subjectively (Ocular Surface Disease Index questionnaire) and objectively, Schirmer test, tear film breakup time, and conjunctival nucleus/cytoplasm ratio by impression cytology.

RESULTS

The Ocular Surface Disease Index score significantly changed from 3.1 ± 2.8 at baseline to 11.9 ± 4.1 and 15.2 ± 3.8 after 1 and 3 months of therapy, respectively, in the sofosbuvir group but had decreased to 7.6 ± 6.2 by 3 months after cessation of therapy. Mean Schirmer test values showed a significant change in the sofosbuvir group from 17.5 ± 2.7 mm at baseline to 10.8 ± 1.4 and 7.0 ± 2.5 mm after 1 and 3 months, respectively, and started returning to normal (11.0 ± 3.3 mm) after 1 month of treatment and mean tear film breakup time varied from 11.0 ± 5.2 seconds at baseline to 9.2 ± 2.6 and 6.1 ± 1.2 seconds at 1 and 3 months, respectively (P < 0.001). The mean nucleus/cytoplasm ratio was significantly different from 1/1.5 at baseline to 1/1.9 and 1/2.4 at 1 and 3 months, respectively, and persisted 3 months after discontinuation of therapy (nucleus/cytoplasm ratio 1/2.0). These changes were not the same in the non-sofosbuvir group.

CONCLUSIONS

Impairment of tear function and squamous metaplastic changes in the ocular surface occurred in patients with chronic hepatitis C treated with sofosbuvir combined with other antivirals.

Making the diagnosis of Sjögren's syndrome in patients with dry eye

Sjögren’s syndrome (SS) is a chronic and progressive systemic autoimmune disease that often presents initially with symptoms of dry eye and dry mouth. Symptoms are often nonspecific and develop gradually, making diagnosis difficult. Patients with dry eye complaints warrant a step-wise evaluation for possible SS. Initial evaluation requires establishment of a dry eye diagnosis using a combination of patient questionnaires and objective ocular tests, including inflammatory biomarker testing. Additional work-up using the Schirmer test and tear film break-up time can differentiate between aqueous-deficient dry eye (ADDE) and evaporative dry eye. The presence of ADDE should trigger further work-up to differentiate between SS-ADDE and non-SS-ADDE. There are numerous non-ocular manifestations of SS, and monitoring for SS-related comorbid findings can aid in diagnosis, ideally in collaboration with a rheumatologist. The clinical work-up of SS can involve a variety of tests, including tear function tests, serological tests for autoantibody biomarkers, minor salivary gland and lacrimal gland biopsies. Examination of classic SS biomarkers (SS-A/Ro, SS-B/La, antinuclear antibody, and rheumatoid factor) is a convenient and non-invasive way of evaluating patients for the presence of SS, even years prior to confirmed diagnosis, although not all SS patients will test positive, particularly those with early disease. Recently, newer biomarkers have been identified, including autoantibodies to salivary gland protein-1, parotid secretory protein, and carbonic anhydrase VI, and may allow for earlier diagnosis of SS. A diagnostic test kit is commercially available (Sjö^®), incorporating these new biomarkers along with the classic autoantibodies. This advanced test has been shown to identify SS patients who previously tested negative against traditional biomarkers only. All patients with clinically significant ADDE should be considered for serological assessment for SS, given the availability of new serological diagnostic tests and the potentially serious consequences of missing the diagnosis.

Diagnosis of dry eye disease and emerging technologies

Dry eye is one of the most commonly encountered problems in ophthalmology. Signs can include punctate epithelial erosions, hyperemia, low tear lakes, rapid tear break-up time, and meibomian gland disease. Current methods of diagnosis include a slit-lamp examination with and without different stains, including fluorescein, rose bengal, and lissamine green. Other methods are the Schirmer test, tear function index, tear break-up time, and functional visual acuity. Emerging technologies include meniscometry, optical coherence tomography, tear film stability analysis, interferometry, tear osmolarity, the tear film normalization test, ocular surface thermography, and tear biomarkers. Patient-specific considerations involve relevant history of autoimmune disease, refractive surgery or use of oral medications, and allergies or rosacea. Other patient considerations include clinical examination for lid margin disease and presence of lagophthalmos or blink abnormalities. Given a complex presentation and a variety of signs and symptoms, it would be beneficial if there was an inexpensive, readily available, and reproducible diagnostic test for dry eye.

Limbal stem cell deficiency and ocular phenotype in ectrodactyly-ectodermal dysplasia-clefting syndrome caused by p63 mutations

OBJECTIVE

To describe the ocular phenotype in patients with ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome (MIM#604292) and to determine the pathogenic basis of visual morbidity.

DESIGN

Retrospective case series.

PARTICIPANTS

Nineteen families (23 patients) affected by EEC syndrome from the United Kingdom, Ireland, and Italy.

METHODS

General medical examination to fulfill the diagnostic criteria for EEC syndrome and determine the phenotypic severity. Mutational analysis of p63 was performed by polymerase chain reaction-based bidirectional Sanger sequencing. All patients with EEC syndrome underwent a complete ophthalmic examination and ocular surface assessment. Limbal stem cell deficiency (LSCD) was diagnosed clinically on the basis of corneal conjunctivalization and anatomy of the limbal palisades of Vogt. Impression cytology using immunofluorescent antibodies was performed in 1 individual. Histologic and immunohistochemical analyses were performed on a corneal button and corneal pannus from 2 EEC patients.

MAIN OUTCOME MEASURES

The EEC syndrome phenotypic severity (EEC score), best-corrected Snellen visual acuity (decimal fraction), slit-lamp biomicroscopy, tear function index, tear breakup time, LSCD, p63 DNA sequence variants, impression cytology, and corneal histopathology.

RESULTS

Eleven heterozygous missense mutations in the DNA binding domain of p63 were identified in all patients with EEC syndrome. All patients had ocular involvement and the commonest was an anomaly of the meibomian glands and lacrimal drainage system defects. The major cause of visual morbidity was progressive LSCD, which was detected in 61% (14/23). Limbal stem cell deficiency was related to advancing age and caused a progressive keratopathy, resulting in a dense vascularized corneal pannus, and eventually leading to visual impairment. Histologic analysis and impression cytology confirmed LSCD.

CONCLUSIONS

Heterozygous p63 mutations cause the EEC syndrome and result in visual impairment owing to progressive LSCD. There was no relationship of limbal stem cell failure with the severity of EEC syndrome, as classified by the EEC score, or the underlying molecular defect in p63.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

The challenge of dry eye diagnosis

The currently available methods for the diagnosis of dry eye are still far from being perfect for a variety of reasons. This review attempts to highlight the advantages and disadvantages of both traditional tests (such as Schirmer’s test, break-up time and ocular surface staining) and innovative noninvasive procedures, including tear meniscus height measurement, corneal topography, functional visual acuity, tear interferometry, tear evaporimetry and tear osmolarity assessment.

A clinical alternative to fluorophotometry for measuring tear production in the diagnosis of dry eye

PURPOSE

To determine the utility of the tear function index (Liverpool modification TFI) in assessing tear turnover rate (TTR), evaluate association of tear clearance rate (TCR) and TFI with measurements of TTR by fluorophotometry, and determine effectivity of these test measures in dry eye (DE) diagnosis.

METHODS

Forty-one subjects with DE and 15 control subjects participated. Tests included symptoms, fluorophotometry (by automated scanning fluorophotometry), and TCR and TFI from a prepared Liverpool modification TFI strip.

RESULTS

Significant differences between subjects with DE and control subjects were found for all tests. Although wetting length values gave highest sensitivity (SS) and specificity (SP) (71% and 73%, respectively), this resulted from a high degree of selection bias because the Schirmer test was one of the inclusion criteria for patients entering the study. Therefore, the best tear production test was found to be TTR (SS 71% and SP 60%). The TTR test is not readily available in clinical settings; therefore, associations between the TTR test and other tests were determined. Significant correlations were found between TTR and wetting length/TCR/TFI, indicating these latter clinical tests useful as surrogates. The strongest correlations, TTR/TCR at 0.69 (P = 0.000) and TTR/TFI at 0.65 (P = 0.000), indicate TCR/TFI with the Liverpool test can be used as an alternative to TTR by fluorophotometry. The diagnostic effectiveness between these tests was compared, with both TCR and TFI found to have equal effectivity of 78% SS and 40% SP (TCR) and 83% SS and 40% SP (TFI).

CONCLUSIONS

TCR measured by the commercially available Liverpool modification TFI strip is an acceptable alternative to TTR by fluorophotometry as a measure of tear production. It is effective as a single test for the discrimination of those with DE from those without the condition.

Methodologies to diagnose and monitor dry eye disease: report of the Diagnostic Methodology Subcommittee of the International Dry Eye WorkShop (2007)

The role of the Diagnostic Methodology Subcommittee of the Dry Eye Workshop was 1) to identify tests used to screen, diagnose and monitor dry eye disease, 2) to establish criteria for test performance, and 3) to consider the utility of tests in a variety of clinical settings. The committee created a database of tests used to diagnose and monitor dry eye, each compiled by an expert in the field (rapporteur) and presented within a standard template. Development of the templates involved an iterative process between the Chairman of the subcommittee, the rapporteurs, and, at times, an additional group of expert reviewers. This process is ongoing. Each rapporteur was instructed on how to the complete a template, using a proforma template and an example of a completed template. Rapporteurs used the literature and other available sources as the basis for constructing their assigned template. The chairman of the subcommittee modifed the template to produce a standardized version and reviewed it with the rapporteur. The completed database will be searchable by an alphabetical list of test names, as well as by functional groupings, for instance, tests of aqueous dynamics, lipid functions, etc. The templates can be accessed on the website of the Tear Film and Ocular Surface Society (www.tearfilm.org). This report provides a general overview of the criteria applied in the development of tests for screening and diagnosis.

Tear Function Changes During Interferon and Ribavirin Treatment in Patients With Chronic Hepatitis C

PURPOSE

To evaluate symptoms and changes in tear function and the ocular surface with interferon and ribavirin therapy for chronic hepatitis C.

METHODS

Nineteen patients with chronic hepatitis C undergoing a course of interferon alfa-2b/ribavirin therapy and 19 age- and sex-matched controls participated in this prospective study. Patients were evaluated for dry eye subjectively (15-symptom assessment questionnaire) and objectively, including ophthalmologic examination, Schirmer test, tear clearance rate (TCR), tear function index (TFI), and nucleus/cytoplasm (N/C) ratio of conjunctival epithelial cell by impression cytology. All tests were performed before antiviral therapy (baseline); at 1, 3, and 6 months after initiation of therapy; and at 3 and 6 months after completing the 6-month course of treatment. All the tear functional tests and impression cytology results in controls were compared with pretreatment baseline of study group, using the Student t test. A paired t test was used to compare mean patient follow-up values with mean patient baseline values.

RESULTS

Patients' mean score on the dry eye symptom assessment questionnaire was significantly (P < 0.05) higher than baseline after 1 and 3 months of therapy, peaked after 6 months of therapy, remained significantly elevated at 3 months after completion of therapy, but had decreased to almost baseline by 6 months after cessation of therapy. Compared with baseline, mean Schirmer test values showed a significant change only at 1 month after the start of treatment. In contrast, mean TCR, mean TFI, and mean N/C ratio were significantly different from baseline at every examination, including 6 months after discontinuation of therapy. After 6 months of therapy, 4 patients (21%) had advanced squamous metaplasia (stage 3 or 4), but 2 patients still had mild squamous metaplasia (stage 2) even 6 months after the completion of therapy.

CONCLUSIONS

Impairment of tear dynamics and squamous metaplastic changes in the ocular surface occurred in patients with chronic hepatitis C treated with interferon alfa-2b and ribavirin. Symptoms of dry eye were mild and reversible; however, abnormalities in tear dynamics and the ocular surface persisted even 6 months after discontinuation of treatment.