Jianjiang Xu

A new tonometer--the Corvis ST tonometer: clinical comparison with noncontact and Goldmann applanation tonometers.

PURPOSE To compare intraocular pressure (IOP) measurements obtained using the Topocon noncontact tonometer (NCT), the Goldmann applanation tonometer (GAT), and the Corvis ST (CST), a newly developed tonometer with features of visualization and measurement of the corneal deformation response to an air impulse. A secondary objective was to assess the agreement among the devices. METHODS Fifty-nine participants, including glaucoma patients (36 cases) and control volunteers (23 cases), were enrolled. One eye was selected randomly for further study. IOP measurements were obtained with the CST, NCT, and GAT by two experienced clinicians. IOP values were compared. Intraobserver variability and interobserver variability were assessed by the coefficient of variation and intraclass correlation coefficient. Device agreement was calculated by Bland-Altman analysis. RESULTS Mean IOP for all examined eyes was 18.9 ± 5.8 mm Hg for CST, 21.3 ± 6.8 mm Hg for NCT, and 20.3 ± 5.7 mm Hg for GAT. There was no statistically significant difference in IOP measurements among the tonometers except between the CST and NCT. Correlation analysis showed a high correlation between each pair of devices (all P < 0.001). The CST displayed the best intraobserver variability and interobserver variability. Bland-Altman analysis revealed a bias between CST and GAT, CST and NCT, and GAT and NCT of -1.3, -2.4, and -1.1 mm Hg, with 95% limits of agreement of -6.2 to 3.5 mm Hg, -10.1 to 5.2 mm Hg, and -8.3 to 6.2 mm Hg, respectively. CONCLUSIONS The CST offers an alternative method for measuring IOP. IOP measurements taken with these devices may not be interchangeable.

Impact of Dry Eye Syndrome on Vision-Related Quality of Life in a Non-Clinic-Based General Population

BackgroundDry eye syndrome (DES) is a common ocular disorder occurring in general population. The purpose of this study is to evaluate the impact of DES on vision-related quality of life (QoL) in a non-clinic-based general population.MethodsThis population-based cross-sectional study enrolled subjects older than 40 years, who took part in an epidemiological study on dry eye in Sanle Community, Shanghai. Apart from the collection of sociodemographics, dry eye symptoms, and other clinical data, a Chinese version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) was administered to all subjects. Comparisons of the NEI VFQ-25 subscale item scores and composite score were made among subgroups divided according to the presence of dry eye symptoms or signs. Multivariate regression analysis was performed to investigate the relationship between the clinical variables and the VFQ-25 composite score.ResultsA total of 229 participants were enrolled in the study, with an average age of (60.7 ±10.1) years old. Majority of these participants were female (59.8 %, 137/229). The total DES symptom scores (TDSS) in subjects either with definite DES or only with dry eye symptoms were significantly higher (F = 60.331, P < 0.001). The values of tear break-up time (TBUT) and Schirmer test were significantly lower in participants with DES and those with dry eye signs only (F = 55.158 and 40.778, P < 0.001). The composite score of the NEI VFQ-25 was significantly lower in subjects with DES (F = 4.901, P = 0.003). Moreover, the subscale scores of ocular pain and mental health were significantly lower in those with either DES or dry eye symptoms only (F = 10.962 and 7.362 respectively, both P < 0.001). The multiple regression analysis showed that the TDSS had a significant negative correlation with the VFQ-25 composite score as well as with the subscale score for ocular pain and mental health, even after the adjustment of all other factors (all P < 0.01).ConclusionsThe symptoms of dry eye are associated with an adverse impact on vision-related QoL in non-clinic-based general population, which is mainly represented as more ocular pain and discomfort, and impaired mental health as well. Apart from clinical examination, it is also important to refer to subjective symptoms and QoL scores when assessing the severity of DES.

Assessment of tear film stability in dry eye with a newly developed keratograph.

Purpose: To investigate the applicability of a newly developed corneal topographer in assessing tear film stability. Methods: This is a prospective, case–control study. Forty-four Chinese dry eye patients and 41 normal subjects were recruited. Noninvasive tear film break-up time (NI-BUT) was measured using a new method based on a corneal topographer equipped with modified scan software. The reliability of the measurements was determined. Then, the correlations between the NI-BUT and the traditional fluorescein tear film break-up time, Schirmer I test values, and inferior tear meniscus height measurements were determined. The receiver operating characteristic curve technique was used to evaluate the NI-BUT examination in the diagnosis of dry eye. Results: In total, a significant difference between the NI-BUT and the fluorescein tear film break-up time was found (3.2 ± 2.3 seconds vs. 5.2 ± 3.4 seconds; P < 0.001). The coefficient of variation and intraclass correlation coefficient values of NI-BUT were 12.8% and 0.93, respectively, for NI-BUT for intraobserver repeatability and 15.4% and 0.88, respectively for interobserver repeatability. The NI-BUT showed a good correlation with other dry eye examinations (all P < 0.05). In addition, the NI-BUT was significantly shorter in dry eye patients (2.0 ± 0.2 seconds) than in normal subjects (4.3 ± 0.3 seconds; P < 0.001). When the cutoff value was set at <2.65 seconds, the sensitivity and specificity of the test were 84.1% and 75.6%, respectively. Conclusions: Measurements of NI-BUT obtained with the newly developed corneal topographer may provide a simple, noninvasive screening test for dry eyes with acceptable sensitivity, specificity, and repeatability.

TFOS DEWS II Management and Therapy Report

The members of the Management and Therapy Subcommittee undertook an evidence-based review of current dry eye therapies and management options. Management options reviewed in detail included treatments for tear insufficiency and lid abnormalities, as well as anti-inflammatory medications, surgical approaches, dietary modifications, environmental considerations and complementary therapies. Following this extensive review it became clear that many of the treatments available for the management of dry eye disease lack the necessary Level 1 evidence to support their recommendation, often due to a lack of appropriate masking, randomization or controls and in some cases due to issues with selection bias or inadequate sample size. Reflecting on all available evidence, a staged management algorithm was derived that presents a step-wise approach to implementing the various management and therapeutic options according to disease severity. While this exercise indicated that differentiating between aqueous-deficient and evaporative dry eye disease was critical in selecting the most appropriate management strategy, it also highlighted challenges, based on the limited evidence currently available, in predicting relative benefits of specific management options, in managing the two dry eye disease subtypes. Further evidence is required to support the introduction, and continued use, of many of the treatment options currently available to manage dry eye disease, as well as to inform appropriate treatment starting points and understand treatment specificity in relation to dry eye disease subtype.

An in vivo confocal microscopy and impression cytology analysis of goblet cells in patients with chemical burns.

PURPOSE To evaluate goblet cell density (GCD) on conjunctiva and cornea in patients with ocular chemical burns by in vivo laser scanning confocal microscopy (LSCM) and impression cytology (IC) and to explore the correlation between two methods. METHODS Fifty-four patients (58 eyes) with chemical burn were enrolled in the study. LSCM was applied to identify the goblet cells on conjunctiva and cornea under in vivo conditions, and GCD was analyzed with the customized software. Impression cytology was then performed, and the biopsy specimens were stained to visualize goblet cells in vitro and to measure the density. Statistical software was used to analyze the correlation between GCD taken by two methods. RESULTS Conjunctival goblet cells could be discriminated in 55 eyes and 57 eyes by in vivo LSCM and IC. They could be identified on the cornea in nine eyes and eight eyes by two methods. The positive rate of two methods had no significant difference. GCDs on conjunctiva measured by in vivo LSCM and IC were 136 +/- 79 cells/mm(2) and 121 +/- 66 cells/mm(2). Median GCDs on cornea detected by two methods were 30 cells/mm(2) and 23 cells/mm(2), respectively. A significant positive correlation was found between the GCDs on conjunctiva measured by these two methods as well as the GCDs on cornea. CONCLUSIONS GCD decreased in patients with chemical burns. A positive correlation was found between GCD measured by in vivo LSCM and IC after chemical burns. In vivo LSCM was a promising device to study goblet cells in vivo under pathologic conditions.

In vivo confocal microscopy of conjunctival goblet cells in patients with Sjögren's syndrome dry eye

Background To study the morphology and the density of conjunctival goblet cells (GC) in patients with Sjögrens syndrome dry eye with in vivo laser scanning confocal microscopy (LSCM), and to explore its correlation with the GC density detected by impression cytology. Methods A total of 43 Sjögrens syndrome dry eye patients were recruited. All were required to fill in the Ocular Surface Disease Index Questionnaires. The tear break-up time was measured, followed by corneal fluorescein staining examination and Schirmer I test. The images of conjunctiva were taken by the Heidelberg retina tomography (HRT-II)/Rostock cornea module. Finally, the specimens for impression cytology were obtained. SPSS V.13.0 software was used to analyse the data. Results Tear film function test showed that all patients had moderate to severe dry eye. The GC in LSCM images was characterised as a large hyper-reflective oval-shape cell with relatively homogeneous brightness. Though GC density assessed by LSCM (332±137) cells/mm2 was higher than that measured by impression cytology (200±141) cells/mm2, they showed a significant positive correlation, ρ=0.908 (p<0.05). Conclusion Conjunctival GC could be easily discriminated under the LSCM. LSCM may be a valuable tool in monitoring the progress and the follow-up of patients with Sjögrens syndrome dry eye.

Age-Related Changes in Human Corneal Epithelial Thickness Measured With Anterior Segment Optical Coherence Tomography

PURPOSE To measure corneal and limbal epithelial thickness (ET) in normal subjects and to evaluate its variation with age by using anterior segment optical coherence tomography (AS-OCT). METHODS A total of 180 normal subjects (180 healthy eyes) were enrolled and divided into four groups according to age: A (0-20 years), B (21-40 years), C (41-60 years), and D (>60 years). Cornea and limbus were imaged with OCT. Corneal ET (CET) was obtained automatically by the built-in analysis software of the OCT system. Limbal ET (LET) in four quadrants was manually measured from OCT images. RESULTS Corneal ET of a central 2-mm diameter zone in groups A, B, C, and D were 53.4 ± 2.8 μm, 53.4 ± 2.7 μm, 53.2 ± 3.0 μm, and 52.9 ± 3.3 μm, respectively, N showing no significant change with aging. In the paracentral zone extending to 6-mm diameter, correlation analysis suggested that CET was inversely associated with age (P < 0.05). Limbal ET in the nasal and the temporal quadrants were similar and decreased with aging, the averages were 58.3 ± 8.1 μm, 54.1 ± 6.1 μm, 51.2 ± 6.1 μm, 51.6 ± 5.2 μm for groups A, B, C and D, respectively; while age seemed to have no effect on LET of the superior and the inferior quadrant. CONCLUSIONS The paracentral corneal epithelium, as well as the nasal and temporal limbal epithelium, became thinner with aging, while the central CET seemed to remain constant. Measurement with AS-OCT of the corneal and limbal ET could aid in clinical assessment and planning treatments of the cornea.

Comparison of Anterior Segment Parameters Between the Acute Primary Angle Closure Eye and the Fellow Eye

PURPOSE To investigate features of the anterior segment (AS) of the affected eye compared to the fellow eye within the same patient in acute primary angle closure (APAC). METHODS Thirty-six patients with unilateral APAC were imaged with AS optical coherence tomography (OCT) before medical or laser treatment for the acute attack. Anterior chamber depth (ACD), iris curvature (IC), iris thickness at 750 μm from the scleral spur (IT750), lens vault (LV), anterior chamber area (ACA), and iris area were estimated by using ImageJ software (version 1.46). Conditional logistic regression analysis was performed to find the associated factors with the prediction of APAC. RESULTS When compared to fellow eyes, affected eyes showed significantly shallower ACD (1.90 ± 0.24 and 1.55 ± 0.30 mm, respectively; P < 0.001), smaller ACA (12.96 ± 2.38 and 10.41 ± 2.34 mm(2), respectively; P < 0.001), and greater LV (1.06 ± 0.31 and 1.26 ± 0.36 mm, respectively; P = 0.017). Less IC (odds ratio [OR]*100: 0.935 [95% confidence interval: 0.894, 0.979], P = 0.004) and IT750 (OR*100: 0.904 [0.8294, 0.987], P = 0.024), greater central corneal thickness (OR*100: 2.100 [1.245, 3.542], P = 0.005), greater LV (OR: 66.7 [2.529, 1761.3], P = 0.012), less ACA (OR: 0.386 [0.193, 0.774], P = 0.007), and less ACD (OR*100: 0.912 [0.855, 0.972], P = 0.005) were significantly associated with prediction of APAC. CONCLUSIONS Greater LV was the most prominent feature of affected eyes compared to fellow eyes in APAC patients when assessed by AS OCT. This may play a role in the development of acute attack in primary angle closure.

Evaluation of age-related changes in human palpebral conjunctiva and meibomian glands by in vivo confocal microscopy.

Purpose: To investigate the age-related changes in human palpebral conjunctiva and meibomian glands by in vivo confocal microscopy. Methods: Forty-nine healthy volunteers (20 men and 29 women; mean age, 43.4 ± 22.7 years; range, 9-85 years) were recruited from the community. Laser scanning confocal microscopy was used to observe and measure the upper palpebral conjunctiva and meibomian glands. Customized software was used to analyze the images. The quantitative parameters included the mean densities of goblet cells, conjunctival basal epithelium, Langerhans cells, and meibomian glandular acinar units. Results: Mean densities of goblet cells, conjunctival basal epithelium, Langerhans cells, and meibomian glandular acinar units were 1050 ± 495 cells per square millimeter, 2979 ± 510 cells per square millimeter, 32 ± 16 cells per square millimeter, and 71 ± 27 glands per square millimeter in total subjects, respectively. No statistically significant difference in these 4 parameters was observed between the male and female subjects. Significant negative correlations were noted between age and goblet cell density (r = −0.646; P < 0.0001) and meibomian glandular acinar unit density (r = −0.585; P < 0.0001). However, no significant correlation was detected between the densities of conjunctival basal epithelium or Langerhans cell density and age. Conclusions: Age-related changes under laser scanning confocal microscopy included decreased densities of goblet cells in human palpebral conjunctiva and the acinar units in meibomian glands.

Spectral-Domain Optical Coherence Tomographic Assessment of Schlemm's Canal in Chinese Subjects with Primary Open-angle Glaucoma

PURPOSE To evaluate in vivo features of Schlemms canal (SC) in patients with primary open-angle glaucoma (POAG) with spectral-domain optical coherence tomography (SD-OCT) and to investigate the relationship of SC size with intraocular pressure (IOP) and glaucoma severity. DESIGN Prospective, comparative study. PARTICIPANTS Fifty Chinese patients with newly diagnosed POAG who had not undergone surgery and 50 normal Chinese subjects from a population-based, cross-sectional study in Shanghai. METHODS All participants underwent SD-OCT. The diameter and area of SC were examined in the temporal and nasal sections and measured with customized software. MAIN OUTCOME MEASURES Patient demographics, repeatability and reproducibility assessed with the coefficient of variation (CV) and the intraclass correlation coefficient (ICC), SC parameters and their correlation with IOP, and the mean deviation (MD) of the visual field were analyzed. RESULTS The percentage of sections in which SC was observable was similar between eyes with POAG and normal eyes, and ranged from 78% to 86%. For intraobserver repeatability, the CV and ICC values were 7.9% and 0.97 for diameter, and 13.8% and 0.83 for area, respectively. For interobserver repeatability, the CV and ICC values were 13.6% and 0.89 for diameter, and 13.4% and 0.80 for area, respectively. Significant differences between the 2 groups were found for the average SC area (11332 ± 2015 μm(2) vs. 13991 ± 1357 μm(2); P<0.001), but not for the SC diameter (40.2 ± 7.1 μm vs. 45.2 ± 4.0 μm; P = 0.195). In addition, the mean IOP values correlated well only with the SC area (ρ = -0.674, P<0.001), not with the SC diameter (ρ = -0.103, P = 248). No significant correlations were found between the MD values and the SC parameters. CONCLUSIONS Eyes with POAG have a decreased SC area compared with normal eyes. A correlation between the SC area and the IOP also was observed. However, the degree of glaucoma damage was not consistently associated with the SC area. Spectral-domain OCT could be used for investigating SC changes in patients with glaucoma.