Xinhan Cui

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.

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.

Assessment of corneal epithelial thickness in dry eye patients.

Purpose To investigate the features of corneal epithelial thickness topography with Fourier-domain optical coherence tomography (OCT) in dry eye patients. Methods In this cross-sectional study, 100 symptomatic dry eye patients and 35 normal subjects were enrolled. All participants answered the ocular surface disease index questionnaire and were subjected to OCT, corneal fluorescein staining, tear breakup time, Schirmer 1 test without anesthetic (S1t), and meibomian morphology. Several epithelium statistics for each eye, including central, superior, inferior, minimum, maximum, minimum − maximum, and map standard deviation, were averaged. Correlations of epithelial thickness with the symptoms of dry eye were calculated. Results The mean (±SD) central, superior, and inferior corneal epithelial thickness was 53.57 (±3.31) &mgr;m, 52.00 (±3.39) &mgr;m, and 53.03 (±3.67) &mgr;m in normal eyes and 52.71 (±2.83) &mgr;m, 50.58 (±3.44) &mgr;m, and 52.53 (±3.36) &mgr;m in dry eyes, respectively. The superior corneal epithelium was thinner in dry eye patients compared with normal subjects (p = 0.037), whereas central and inferior epithelium were not statistically different. In the dry eye group, patients with higher severity grades had thinner superior (p = 0.017) and minimum (p < 0.001) epithelial thickness, more wide range (p = 0.032), and greater deviation (p = 0.003). The average central epithelial thickness had no correlation with tear breakup time, S1t, or the severity of meibomian glands, whereas average superior epithelial thickness positively correlated with S1t (r = 0.238, p = 0.017). Conclusions Fourier-domain OCT demonstrated that the thickness map of the dry eye corneal epithelium was thinner than normal eyes in the superior region. In more severe dry eye disease patients, the superior and minimum epithelium was much thinner, with a greater range of map standard deviation.

Assessment of Bulbar Redness with a Newly Developed Keratograph.

PurposeTo determine the validity and reliability of the clinical assessment of bulbar redness (BR) using a newly developed corneal topographer. MethodsThis is a cross-sectional diagnostic evaluation study. The BR scores [Oculus Index (OI)] from 30 eyes of 26 patients with different degrees of conjunctival hyperemia were assessed and scored automatically using a new method: a keratograph equipped with scanning and scoring software. The values obtained via this system were correlated with three image-based comparative subjective scales: the Institute for Eye Research (IER), the Efron, and the Validated Bulbar Redness (VBR) grading scales. The IER and Efron scores were interpolated to 0.1 unit, and the VBR scores were interpolated to 1 unit. We also evaluated the repeatability of each method and the level of agreement between the OI score and the scores achieved using the three other image-based methods. ResultsThere was a significant correlation between the OI score and the scores obtained with the IER (r = 0.921, p < 0.001), Efron (r = 0.958, p < 0.001), and VBR (r = 0.965, p < 0.001) scales. The intraobserver intraclass correlation coefficients were 0.947, 0.874, 0.810, and 0.920 for the OI, IER, Efron, and VBR, respectively, and the intraobserver coefficients of repeatability were 13.924, 16.111, 17.684, and 16.900, respectively. Furthermore, the interobserver intraclass correlation coefficients were 0.889, 0.880, 0.884, and 0.881 for the OI, IER, Efron, and VBR, respectively, and the interobserver coefficients of repeatability were 15.934, 16.366, 22.059, and 21.373, respectively. ConclusionsThe OI is an objective and reliable method for scoring BR. Its reproducibility was the highest of all the four modalities. The keratograph is recommended, therefore, as a suitable alternative for BR assessment.

Impact of Conjunctivochalasis on Visual Quality of Life: A Community Population Survey

Conjunctivochalasis (Cch) is a very common ocular disorder, which can cause an unstable tear film and ocular discomfort. The study of vision-related quality of life (VR-QoL) in a community population with Cch can provide a better understanding of the impact of Cch on common people than objective clinical examinations alone. This cross-sectional comparative study enrolled 360 participants ≥40 years old living in Sanle Community, Shanghai. In the study, 198 subjects were diagnosed with Cch and 86 with dry eye syndrome (DES) without Cch. The remaining 76 subjects were normal controls. Socio-demographical data were collected, and Cch and related ocular symptoms and signs were evaluated. In addition, all participants were required to complete the Chinese version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) and Ocular Surface Disease Index Questionnaire (OSDI). Main outcome measures include the comparison on the OSDI score and VFQ-25 score among the subgroups, and the correlation of these scores with the socio-demographical and clinical data. The results revealed that subjects with Cch had significantly decreased tear film stability even compared with those with DES (P = 0.001). The participants with either Cch or DES reported significantly higher OSDI scores and lower VFQ-25 composite scores than the normal controls (P<0.001 and 0.007 respectively). Further comparisons among the subgroups of Cch revealed that the following factors were associated with higher OSDI scores and lower VFQ-25 composite scores: nasal-side Cch, chalasis folds higher than tear meniscus height, punctal occlusion, or increased extent of chalasis on digital pressure. In conclusion, Cch was associated with an adverse impact on VR-QoL in a community population, and the impairment in VR-QoL had a significant correlation with disease severity and tear film abnormalities.

Vision-Related Quality of Life in Patients with Infectious Keratitis

Purpose To determine the vision-related quality of life (VR-QOL) in patients with infectious keratitis using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). Methods Sixty-five patients with infectious keratitis (IK) were enrolled in the study. The NEI VFQ-25 scores and clinical and demographic data, including age, gender, pathogen, best corrected visual acuity (BCVA), and duration of the disease, were collected from the subjects. The subscale and composite scores were calculated and analyzed. Correlations between the VFQ-25 scores and the clinical and demographic features were also explored. Results The mean age of enrolled subjects was 48.4 years (SD, 16.2), with 44 males (67.7%). The microbial pathogens were viruses (n = 48, 73.8%), fungi (n = 13, 20.0%), and bacteria (n = 4, 6.2%). The mean scores of each VFQ-25 subscale ranged from 31.9 (SD, 28.6) for role difficulties to 92.7 (SD, 13.1) for color vision; the mean composite score was 58.1 (SD, 19.2). Significant differences in scores were observed only in the subscale of dependency among educational levels and in the mental health subscale and the composite among the three pathogen groups. Multivariate regression analysis revealed that VFQ-25 composite score correlated significantly with the BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender. Conclusions Infectious keratitis has extensive impacts on patients and VR-QOL. The BCVA of worse-seeing eye, duration, history of operation for IK treatment, and gender contributed independently to VR-QOL. Early treatment should be encouraged to obtain better visual prognosis and VR-QOL for patients with IK.

Vitamin A Palmitate and Carbomer Gel Protects the Conjunctiva of Patients With Long-term Prostaglandin Analogs Application.

Purpose:To investigate the protective effects of vitamin A palmitate and carbomer gel on the morphology of conjunctival epithelium and density of goblet cells (GCs) in patients on long-term prostaglandin analogs (PGAs) application. Methods:In this prospective cohort study, 23 primary open-angle glaucoma patients and 7 normal-tension glaucoma patients prescribed PGAs for >1 year were enrolled into 3 identical clinical trials and randomized into 3 groups (10 per group). Patients were treated twice daily with vitamin A palmitate eye gel 0.1%, or carbomer eye gel 0.2%, or no additional application of these 2 drugs. Ocular surface disease index questionnaires, Schirmer 1 test without anesthesia, tear break-up time test, and GCs density assessment by in vivo confocal microscopy and conjunctival impression cytology analysis were performed at baseline and at months 1, 3, and 6 of the study. Results:Both vitamin A palmitate and carbomer gel led to a significant improvement in ocular surface disease index questionnaires score and prevented the gradual decline in tear break-up time. Vitamin A palmitate significantly increased the GC density after treatment. The GC density assessed by in vivo confocal microscopy positively correlated with that measured by conjunctival impression cytology. Conclusions:Vitamin A palmitate and carbomer eye gel can effectively relieve dry eye symptom caused by long-term application of PGAs by increasing the GCs density and thereby reducing the toxicity to the conjunctiva. Vitamin A palmitate and carbomer eye gel may be valuable alternatives for glaucoma patients who prescribed long-term PGAs.

Limitations of Keratoplasty in China: A Survey Analysis

Purpose Each year, over 8,000 corneal transplantation surgeries are performed in China. Unlike developed countries, which have established standard requirements for operative experience for corneal specialists, little information exists on surgical training for keratoplasty in China. The aim of this study was to assess the keratoplasty experience of Chinese corneal specialists and to characterize their surgical patterns. Methods One hundred and twenty-one corneal specialists in 16 provinces (65 cities) in China were invited to complete an anonymous survey at the 2014 Chinese Corneal Society annual meeting, which consisted of questions with single or multiple-choice answers. Demographics, the number and type of keratoplasties performed, and the perceived limiting factors for performing keratoplasties were analyzed. Results An overwhelming 89% response rate was achieved. Of the 108 respondents, 76% worked in tertiary centers, and only 23% held a medical doctorate degree. Furthermore, 69% of the participants had received corneal fellowship training of less than one year. Only 71% were capable of keratoplasties. Among those doing keratoplasty, 68% performed less than 50 keratoplasties each year. Of the same group of keratoplasty surgeons, 88% of corneal specialists capable of keratoplasties had performed penetrating keratoplasties, 87% had performed lamellar keratoplasties, 12% had performed deep anterior lamellar keratoplasties, and 5% had performed Descemet’s stripping endothelial keratoplasties. When questioned on the reasons for the low number of keratoplasties performed in China, the respondents deemed the following factors most important: lack of surgical training (71%), a shortage of donor supply (52%), and a lack of curricula (42%). A multivariate logistic regression analysis showed that corneal transplantation capabilities are significantly associated with responders’ education levels and training time. Conclusion Keratoplasty surgery experience is suboptimal for Chinese corneal specialists. Penetrating and lamellar keratoplasties are the preferred surgical patterns. Our findings raise concerns about the adequacy of keratoplasty training in China.

Prevalence and Associated Factors of Pinguecula in a Rural Population in Shanghai, Eastern China

Abstract Purpose: To determine the prevalence and associated factors of pinguecula in a rural Chinese population aged ≥50 years in Eastern China. Methods: This cross-sectional, population-based survey included an age-stratified random sample of 1108 residents living in Lvxiang Town of Jinshan District. Participants were requested to complete a comprehensive questionnaire to collect demographic data, history of systemic diseases and lifestyle details. The presence of pinguecula on slit lamp examination was recorded. The prevalence of pinguecula and its associated factors were investigated by logistic regression models. Results: Among 1108 eligible subjects, 959 participated in the study, with an average age of 65.1 ± 9.2 years (range 50–89 years). The overall age-adjusted prevalence of pinguecula in this population was 75.57% (95% confidence interval 71.79–79.35%). Logistic regression analysis revealed that age (p = 0.002) and working outdoors (daily sunlight exposure ≥2 hours; p = 0.001) were independent risk factors for pinguecula. In addition, sex, education level, alcohol intake, smoking and decreased tear break-up time did not have associations with the development of pinguecula after adjusting for age and outdoor work occupations. Conclusions: The prevalence of pinguecula was 75.57% in this Chinese population aged ≥ 50 years from a coastal rural area of Shanghai, Eastern China, which was higher than the majority of previous findings. Age and working outdoors were independent risk factors for pinguecula.

Meibomian Gland Alteration in Patients with Primary Chronic Dacryocystitis: An In vivo Confocal Microscopy Study

Abstract Purpose: To evaluate meibomian gland (MG) alterations in patients with primary chronic dacryocystitis (PCD) by in vivo confocal microscopy (IVCM), and to correlate the finding with clinical presentation. Methods: Twenty-eight eyes with the diagnosis of PCD and their contralateral unaffected eyes were studied and compared with 27 normal controls. All subjects completed an Ocular Surface Disease Index questionnaire (OSDI) and underwent slit-lamp biomicroscopy examination, tear break-up time (BUT) measurements, fluorescein staining, Schirmer test I, and an IVCM examination of the MG. IVCM parameters, including the MG acinar unit density (MGAUD), periglandular inflammatory cell density (ICD), MG acinar unit longest diameter (MGALD), and MG acinar unit shortest diameter (MGASD) and their correlation with clinical data were analyzed. Results: The mean MG expressibility scores, BUT values, and staining scores were significantly worse in eyes with PCD compared with the contralateral clinically unaffected eyes and controls (p < 0.05). A significant decrease in MGAUD was observed in PCD eyes compared with the controls and the contralateral clinically unaffected eyes. Conversely, the mean ICD and MGASD values were significantly higher in the PCD eyes. There were no significant differences in mean MGALD value between the PCD eyes and the contralateral clinically unaffected eyes. In addition, there were significant changes in the IVCM parameters in the contralateral unaffected eyes compared with the controls, including MGAUD, ICD, MGALD, and MGASD. All IVCM parameters showed a strong, significant correlation with MG dropout grades, MG expressibility, fluorescein staining scores, and OSDI values (all p < 0.05). Conclusions: Patients with unilateral PCD demonstrated significant changes in MG as compared with the contralateral clinically unaffected eyes and controls. The MG function should be closely observed in these patients.