Six-Year Incidence and Risk Factors for Primary Open-Angle Glaucoma and Ocular Hypertension: The Singapore Epidemiology of Eye Diseases Study.

OBJECTIVE: To determine the incidence and risk factors for primary open-angle glaucoma (POAG) and ocular hypertension (OHT) in a multiethnic Asian population. DESIGN: Population-based cohort study. PARTICIPANTS: The Singapore Epidemiology of Eye Diseases study included 10 033 participants in the baseline examination between 2004 and 2011. Of those, 6762 (response rate = 78.8%) participated in the 6-year follow-up visit between 2011 and 2017. METHODS: Standardized examination and investigations were performed, including slit lamp biomicroscopy, intraocular pressure (IOP) measurement, pachymetry, gonioscopy, optic disc examination and static automated perimetry. Glaucoma was defined according to a combination of clinical evaluation, ocular imaging (fundus photo, visual field, and OCT) and criteria given by International Society of Geographical and Epidemiological Ophthalmology. OHT was defined on the basis of elevated IOP over the upper limit of normal; i.e., 20.4 mmHg, 21.5 mmHg, and 22.6 mmHg for the Chinese, Indian, and Malay cohort respectively, without glaucomatous optic disc change. MAIN OUTCOME MEASURES: Incidence of POAG, OHT, and OHT progression. RESULTS: The overall 6-year age-adjusted incidences of POAG and OHT were 1.31% (95% confidence interval [CI], 1.04-1.62) and 0.47% (95% CI, 0.30-0.70). The rate of progression of baseline OHT to POAG at 6 years was 5.32%. Primary open-angle glaucoma incidence was similar (1.37%) in Chinese and Indians and lower (0.80%) in Malays. Malays had higher incidence (0.79%) of OHT than Indians (0.38%) and Chinese (0.37%). Baseline parameters associated with higher risk of POAG were older age (per decade: odds ratio [OR], 1.90; 95% CI, 1.54-2.35; P < 0.001), higher baseline IOP (per mmHg: OR, 1.20; 95% CI, 1.12-1.29; P < 0.001) and longer axial length (per mm: OR, 1.22; 95% CI, 1.07-1.40, P = 0.004). CONCLUSION: Six-year incidence of POAG was 1.31% in a multiethnic Asian population. Older age, higher IOP, and longer axial length were associated with higher risk of POAG. These findings can help in future projections and guide public healthcare policy decisions for screening at-risk individuals. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.

Correction: From 2 dimensions to 3rd dimension: Quantitative prediction of anterior chamber depth from anterior segment photographs via deep-learning.

[This corrects the article DOI: 10.1371/journal.pdig.0000193.].

Assessment of anxiety and depression in patients with Posner-Schlossman syndrome.

BACKGROUND: To assess the anxiety and depression levels in patients with Posner-Schlossman syndrome (PSS) and to determine the potential risk factors. METHODS: In this cross-sectional study, a total of 195 participants, including 93 PSS patients and 102 healthy controls were recruited. Sociodemographic and clinical information were collected for all participants. Hospital Anxiety and Depression scale (HADS) was administered to evaluate the anxiety and depression levels. Visual function (VF) and quality-of-life (QOL) questionnaires were administered to assess variables potentially associated with anxiety and depression. RESULTS: Increased anxiety level was observed in 22 (23.7%) PSS patients as compared to 10 (9.8%) of controls (P = 0.009). While the frequency of depression between the two groups was not significantly different (P = 0.349). The mean anxiety and depression scores were 6.98 ± 4.20 and 6.44 ± 3.66 in PSS patients as compared to 6.67 ± 3.21 (P = 0.564) and 5.96 ± 2.93 (P = 0.311) in controls. Logistic regression analysis showed mental well-being was significantly associated with anxiety (odds ratio [OR] = 0.920, 95% confidence interval [CI] = 0.881-0.962, P < 0.001) and depression (OR = 0.959, CI = 0.926-0.994, P = 0.023) in PSS patients. CONCLUSION: More patients with PSS may experience anxiety as compared to healthy controls. Mental well-being is an independent risk factor for anxiety and depression. It is important for ophthalmologists to be aware of these factors and should pay more attention on mental health when PSS is managed in clinic.

From 2 dimensions to 3rd dimension: Quantitative prediction of anterior chamber depth from anterior segment photographs via deep-learning.

Anterior chamber depth (ACD) is a major risk factor of angle closure disease, and has been used in angle closure screening in various populations. However, ACD is measured from ocular biometer or anterior segment optical coherence tomography (AS-OCT), which are costly and may not be readily available in primary care and community settings. Thus, this proof-of-concept study aims to predict ACD from low-cost anterior segment photographs (ASPs) using deep-learning (DL). We included 2,311 pairs of ASPs and ACD measurements for algorithm development and validation, and 380 pairs for algorithm testing. We captured ASPs with a digital camera mounted on a slit-lamp biomicroscope. Anterior chamber depth was measured with ocular biometer (IOLMaster700 or Lenstar LS9000) in data used for algorithm development and validation, and with AS-OCT (Visante) in data used for testing. The DL algorithm was modified from the ResNet-50 architecture, and assessed using mean absolute error (MAE), coefficient-of-determination (R2), Bland-Altman plot and intraclass correlation coefficients (ICC). In validation, our algorithm predicted ACD with a MAE (standard deviation) of 0.18 (0.14) mm; R2 = 0.63. The MAE of predicted ACD was 0.18 (0.14) mm in eyes with open angles and 0.19 (0.14) mm in eyes with angle closure. The ICC between actual and predicted ACD measurements was 0.81 (95% CI 0.77, 0.84). In testing, our algorithm predicted ACD with a MAE of 0.23 (0.18) mm; R2 = 0.37. Saliency maps highlighted the pupil and its margin as the main structures used in ACD prediction. This study demonstrates the possibility of predicting ACD from ASPs via DL. This algorithm mimics an ocular biometer in making its prediction, and provides a foundation to predict other quantitative measurements that are relevant to angle closure screening.

Relationship between vision impairment and employment.

AIMS: To examine the relationship between vision impairment (VI) and employment outcomes in a multiethnic Asian population. METHODS: We included 7608 Asian individuals aged ≥40 years (mean (SD) age: 58.4 (10.3) years; 64.8% male) from the Singapore Epidemiology Eye Disease Study (response rate: 78.8%), a population-based cohort study (mean follow-up period: 6.2 years). Presenting visual acuity (VA) was assessed using a logarithm of the minimum angle of resolution (logMAR) chart, with VI defined as mild (VA >0.3 to <0.6 logMAR) and moderate to severe (VA ≥0.6 logMAR). Self-reported employment statuses at both baseline and follow-up were used as outcomes. Underemployment was defined as a decline in occupational skill level, categorised by International Standard Classification of Occupations, at follow-up compared with baseline. Multinomial logistic regression models were used to determine independent associations between VI and various employment outcomes, adjusted for variables that were found to significantly differ across employment statuses. RESULTS: Presenting VI was prevalent in 20.2% (N=1536) of participants. Compared with those without VI, participants with mild and moderate to severe VI were more likely to be unemployed at baseline (OR 1.47, 95% CI 1.15 to 1.87, p=0.002 and 2.74, 95% CI 1.94 to 3.89, p<0.001, respectively). At follow-up, participants with any VI at baseline were more likely to be underemployed (OR 1.46, 95% CI 1.03 to 2.05, p=0.033). CONCLUSION: VI, even when mild, is associated with unemployment and underemployment. Future studies should investigate whether visual interventions could be used as part of a multipronged strategy to improve employment outcomes for the population.

Machine learning identifying peripheral circulating metabolites associated with intraocular pressure alterations.

AIMS: To identify blood metabolite markers associated with intraocular pressure (IOP) in a population-based cross-sectional study. METHODS: This study was conducted in a multiethnic Asian population (Chinese, n=2805; Indians, n=3045; Malays, n=3041 aged 40-80 years) in Singapore. All subjects underwent standardised systemic and ocular examinations, and biosamples were collected. Selected metabolites (n=228) in either serum or plasma were analysed and quantified using nuclear magnetic resonance spectroscopy. Least absolute shrinkage and selection operator regression was used for metabolites selection. Multivariable linear regression was used to evaluate the relationship between metabolites and IOP in each of the three ethnic groups, followed by a meta-analysis combining the three cohorts. RESULTS: Six metabolites, including albumin, glucose, lactate, glutamine, ratio of saturated fatty acids to total fatty acids (SFAFA) and cholesterol esters in very large high-density lipoprotein (HDL), were significantly associated with IOP in all three cohorts. Higher levels of albumin (per SD, beta=0.24, p=0.002), lactate (per SD, beta=0.27, p=0.008), glucose (per SD, beta=0.11, p=0.010) and cholesterol esters in very large HDL (per SD, beta=0.47, p=0.006), along with lower levels of glutamine (per SD, beta=0.17, p<0.001) and SFAFA (per SD, beta=0.21, p=0.008) were associated with higher IOP levels. CONCLUSION: We identify several novel blood metabolites associated with IOP. These findings may provide insight into the physiological and pathological processes underlying IOP control.

Associations between visual impairment, incident falls and fall frequency among older asians: longitudinal findings from the Singapore Epidemiology of Eye Diseases study.

BACKGROUND: Association between baseline visual impairment (VI) bilaterality and severity, and associated causes; and incident and frequent falls at 6 years in a multiethnic Asian population aged ≥60 years. METHODS: It is a population-based prospective cohort study. Visual acuity was clinically measured at both visits. Self-reported incidence and frequency of falls were defined as having no fall at baseline but having one fall and ≥2 incident falls in the 12 months prior to the follow-up visit, respectively. RESULTS: Of the 1972 older participants (mean age (SD): 67.37 (5.4) years), 253 (12.8%) and 69 (3.5%) reported at least one fall and ≥2 falls, respectively, at a 6-year follow-up. After multivariable adjustments, baseline bilateral VI, but not unilateral, was associated with higher odds of any incident falls (mild bilateral VI: OR=1.79, 95% CI 1.07 to 2.98; moderate-severe VI in one eye and mild VI in the other eye: OR=1.58, 95% CI 1.01 to 2.47). However, having any form of bilateral VI (OR ranging between 2.46 and 4.32; all p<0.05) and even unilateral mild VI (OR=2.34, 95% CI 1.09 to 5.03) significantly increased the odds of incident frequent falls, compared with bilateral normal vision. VI caused by correctable (OR=2.02, 95% CI 1.19 to 3.44) and uncorrectable (OR=3.09, 95% CI 1.08 to 8.80) eye conditions were both associated with greater odds of incident frequent falls, compared with no VI. CONCLUSIONS: Baseline bilateral but not unilateral VI conferred nearly two-fold higher odds of incident fall. Importantly, even mild unilateral VI conferred a substantially greater likelihood of frequent falls from correctable and uncorrectable conditions.

Smartphone-Acquired Anterior Segment Images for Deep Learning Prediction of Anterior Chamber Depth: A Proof-of-Concept Study.

Purpose: To develop a deep learning (DL) algorithm for predicting anterior chamber depth (ACD) from smartphone-acquired anterior segment photographs. Methods: For algorithm development, we included 4,157 eyes from 2,084 Chinese primary school students (aged 11-15 years) from Mojiang Myopia Progression Study (MMPS). All participants had with ACD measurement measured with Lenstar (LS 900) and anterior segment photographs acquired from a smartphone (iPhone Xs), which was mounted on slit lamp and under diffuses lighting. The anterior segment photographs were randomly selected by person into training (80%, no. of eyes = 3,326) and testing (20%, no. of eyes = 831) dataset. We excluded participants with intraocular surgery history or pronounced corneal haze. A convolutional neural network was developed to predict ACD based on these anterior segment photographs. To determine the accuracy of our algorithm, we measured the mean absolute error (MAE) and coefficient of determination (R 2) were evaluated. Bland Altman plot was used to illustrate the agreement between DL-predicted and measured ACD values. Results: In the test set of 831 eyes, the mean measured ACD was 3.06 ± 0.25 mm, and the mean DL-predicted ACD was 3.10 ± 0.20 mm. The MAE was 0.16 ± 0.13 mm, and R 2 was 0.40 between the predicted and measured ACD. The overall mean difference was -0.04 ± 0.20 mm, with 95% limits of agreement ranging between -0.43 and 0.34 mm. The generated saliency maps showed that the algorithm mainly utilized central corneal region (i.e., the site where ACD is clinically measured typically) in making its prediction, providing further plausibility to the algorithm's prediction. Conclusions: We developed a DL algorithm to estimate ACD based on smartphone-acquired anterior segment photographs. Upon further validation, our algorithm may be further refined for use as a ACD screening tool in rural localities where means of assessing ocular biometry is not readily available. This is particularly important in China where the risk of primary angle closure disease is high and often undetected.

A Multimodal Classification Architecture for the Severity Diagnosis of Glaucoma Based on Deep Learning.

Glaucoma is an optic neuropathy that leads to characteristic visual field defects. However, there is no cure for glaucoma, so the diagnosis of its severity is essential for its prevention. In this paper, we propose a multimodal classification architecture based on deep learning for the severity diagnosis of glaucoma. In this architecture, a gray scale image of the visual field is first reconstructed with a higher resolution in the preprocessing stage, and more subtle feature information is provided for glaucoma diagnosis. We then use multimodal fusion technology to integrate fundus images and gray scale images of the visual field as the input of this architecture. Finally, the inherent limitation of convolutional neural networks (CNNs) is addressed by replacing the original classifier with the proposed classifier. Our architecture is trained and tested on the datasets provided by the First Affiliated Hospital of Kunming Medical University, and the results show that the proposed architecture achieves superior performance for glaucoma diagnosis.

Different impact of early and late stages irreversible eye diseases on vision-specific quality of life domains.

To determine the differential impact of the irreversible eye diseases on vision-related quality of life (VRQoL) in a multi-ethnic Asian population. 2652 participants from the Singapore Epidemiology of Eye Disease Study, with any of the following early and late-stage eye conditions including age-related macular degeneration (AMD, n = 158), diabetic retinopathy (DR, n = 105; non vision threatening [non-VTDR]; VTDR), glaucoma (n = 57) and myopic macular degeneration (MMD, n = 106), or none of the above (controls, 2226 [83.9%]) were included. Rasch-scaled scores of the Emotional well-being Mobility and Reading subscales of the Impact of Vision Impairment (IVI) questionnaire, collectively referred to as "VRQoL" were assessed. Multivariable linear regression analyses and pairwise comparisons adjusting for age, gender, ethnicity, socio-economic status, BMI, smoking, alcohol use, presence of systemic diseases and presenting VI were performed to assess and compare the impact of the presence and severity of each eye condition on the three IVI domains. Multivariable adjusted pairwise comparisons of VRQoL between early stages of the four eye diseases showed no significant differences (all P > 0.05). For late stage diseases, individuals with VTDR had significantly larger decrements in Emotional well-being compared to glaucoma (ß - 0.81; 95% CI - 1.47 to - 0.16) and MMD (ß - 1.17; 95% CI - 2.16 to - 0.18); and Reading decrements compared to glaucoma (ß - 0.66; 95% CI - 1.22 to - 0.11). When compared to late glaucoma, individuals with late AMD (ß - 0.76; 95% CI - 1.50 to - 0.01) had significantly larger IVI Mobility subscale decrements. VTDR and late AMD, appear to have the greatest impact on VRQoL, compared to late glaucoma and MMD, suggesting a differential impact of late-stage eye disease categorization on VRQoL.

The longitudinal association between cognitive impairment and incident visual impairment in a multiethnic Asian population: a prospective cohort study.

BACKGROUND: The relationship between baseline cognitive impairment (CI) and incident visual impairment (VI) in Asians is unclear. OBJECTIVE: To determine the associations between baseline CI with incident VI and visual acuity (VA) at 6-year follow-up in multiethnic Asians. DESIGN: Cohort. SETTING: Population-based. SUBJECTS: Two thousand three hundred and twenty-four adults aged ≥60 years from the Singapore Epidemiology of Eye Diseases Study (response rate 64%). METHODS: CI was defined using the validated Abbreviated Mental Test (AMT). VA was objectively measured using a LogMAR chart. Any incident VI was defined as having no VI (Snellen's VA better than or equal to 20/40) at baseline but present (VA worse than 20/40) at 6-year follow-up. VI severity was defined according to the International Classification of Diseases, 11th Revision. Associations were assessed using logistic and linear regression models. RESULTS: Of the 2,324 participants, 248 had CI at baseline. Presence of baseline CI was associated with more than twice the odds of any incident VI, incident mild and moderate-severe VI (OR [95% confidence interval]: 2.48 [1.55-3.90], 2.07 [1.17-3.55], and 2.61 [1.36-4.93], respectively) and worse VA (ß [95% confidence interval]: 0.026 [0.006-0.046]) at 6-year follow-up. The leading causes of incident VI were cataract and under-corrected refractive error. CONCLUSIONS: Older adults with CI had more than double the odds of VI development and poorer VA than their cognitively intact counterparts, and most causes of incident VI were correctable. Strategies such as targeted vision screening and early intervention for early detection and management of vision loss in patients with cognitive decline are warranted.

Novel Serum and Urinary Metabolites Associated with Diabetic Retinopathy in Three Asian Cohorts.

Diabetic retinopathy (DR) is a microvascular complication of diabetes mellitus, a metabolic disorder, but understanding of its pathophysiology remains incomplete. Meta-analysis of three population-based cross-sectional studies (2004-11) representing three major Asian ethnic groups (aged 40-80 years: Chinese, 592; Malays, 1052; Indians, 1320) was performed. A panel of 228 serum/plasma metabolites and 54 urinary metabolites were quantified using nuclear magnetic resonance (NMR) spectroscopy. Main outcomes were defined as any DR, moderate/above DR, and vision-threatening DR assessed from retinal photographs. The relationship between metabolites and DR outcomes was assessed using multivariate logistic regression models, and metabolites significant after Bonferroni correction were meta-analyzed. Among serum/plasma metabolites, lower levels of tyrosine and cholesterol esters to total lipids ratio in IDL and higher levels of creatinine were positively associated with all three outcomes of DR (all p < 0.005). Among urinary metabolites, lower levels of citrate, ethanolamine, formate, and hypoxanthine were positively associated with all three DR outcomes (all p < 0.005). Higher levels of serum/plasma 3-hydroxybutyrate and lower levels of urinary 3-hydroxyisobutyrate were associated with VTDR. Comprehensive metabolic profiling in three large Asian cohorts with DR demonstrated alterations in serum/plasma and urinary metabolites mostly related to amino acids, lipoprotein subclasses, kidney function, and glycolysis.

Comparison of the SITA Faster-a new visual field strategy with SITA Fast strategy.

AIM: To compare visual field defects using the Swedish Interactive Thresholding Algorithm (SITA) Fast strategy with SITA Faster strategy, a newly developed time-saving threshold visual field strategy. METHODS: Ninety-three participants (60 glaucoma patients and 33 normal controls) were enrolled. One eye from each participant was selected randomly for the study. SITA Fast and SITA Faster were performed using the 24-2 default mode for each test. The differences of visual field defects between the two strategies were compared using the test duration, false-positive response errors, mean deviation (MD), visual field index (VFI) and the numbers of depressed test points at the significant levels of P<5%, <2%, <1%, and <0.5% in probability plots. The correlation between strategies was analyzed. The agreement between strategies was acquired by Bland-Altman analysis. RESULTS: Mean test durations were 246.0±60.9s for SITA Fast, and 156.3±46.3s for SITA Faster (P<0.001). The test duration of SITA Faster was 36.5% shorter than SITA Fast. The MD, VFI and numbers of depressed points at P<5%, <2%, <1%, and <0.5% in probability plots showed no statistically significant difference between two strategies (P>0.05). Correlation analysis showed a high correlation for MD (r=0.986, P<0.001) and VFI (r=0.986, P<0.001) between the two strategies. Bland-Altman analysis showed great agreement between the two strategies. CONCLUSION: SITA Faster, which saves considerable test time, has a great test quality comparing to SITA Fast, but may be not directly interchangeable.

Investigation of expression and influence of CTGF and HO-1 in rats with diabetic retinopathy.

The expression and influence mechanism of CTGF and HO-1 in rats with diabetic retinopathy (DR) was investigated. One hundred and thirty male Sprague-Dawley (SD) rats were selected and randomly divided into the control group and DR group, with 65 rats in each group. DR was caused by intraperitoneal injection of streptozotocin in rats in the DR group. There were 55 successful models and 10 failed in the modelling. The successful models were sacrificed at the 2nd, 4th and 6th month, respectively. RT-qPCR technology was used for detection of the expression of CTGF and HO-1 in rat retina in each group, H&E staining for observation of the gradation structure in rat retina and TUNEL method for detection of apoptosis of retinal cells. In the DR group, the retina layers were disordered and a few blood vessels dilated at the 2nd month. In the DR group, the inner membrane of the retina swelled, and the ganglion cells were irregularly arranged at the 4th month. In the DR group, dilatation of the blood vessels was more obvious, the inner membrane edema was more severe, and the arrangement was more irregular at the 6th month. The retinal apoptosis rate of DR rats gradually increased at the 2nd, 4th and 6th month, after which, the CTGF expression gradually increased, but the HO-1 expression gradually decreased in retina in the DR group. However, the mRNA expression of CTGF and HO-1 in the rats at the 2nd, 4th and 6th month in the DR group was higher than that in the control group at the same period. Therefore, CTGF and HO-1 are associated with the occurrence and development of DR in rats and can be considered as targets for the treatment of DR.

Viscocanalostomy combined with trabeculotomy and mitomycin C in the treatment of primary congenital glaucoma.

AIM: To evaluate the long-term outcome of viscocanalostomy combined with trabeculotomy and mitomycin C in the treatment of primary congenital glaucoma. METHODS: This is a retrospective study. Forty-two eyes of 26 patients with primary congenital glaucoma were enrolled. Intraocular pressure (IOP), corneal diameter (mm) and cup/disc (C/D) were measured before and after the surgery respectively. Follow-up period was 30mo. RESULTS: The mean preoperative IOP was 30.6±7.35 mm Hg. Of the 42 eyes, 2 eyes were required conversion to trabeculectomy for the absence of Schlemm's canal. Of remained 40 eyes, 38 eyes (95%) achieved successful IOP control. The average postoperative IOP was 11.69±4.18 mm Hg at 12mo. The mean reduction was 18.91 mm Hg (P<0.0001). Eighteen (75%) eyes presented a reduction in corneal diameter, and 25 (62.5%) eyes presented a C/D ratio reversal after the surgery. There was no serious complication in any patients over the follow-up period. CONCLUSION: Viscocanalostomy combined with trabeculotomy and mitomycin C is useful in the management of primary congenital glaucoma.

[The effect of AQP4 knock out on retinal electrophysiology in laser-induced ocular hypertension mice].

OBJECTIVE: To investigate the effect of aquaporin 4 (AQP4) knock out (KO) on the dysfunction of retinal ganglion cells (RGC) in laser-induced ocular hypertension (OHT) mice. METHODS: Experimental study. AQP4 KO mice (n = 18, 36 eyes) and wide type (WT) mice (n = 18, 36 eyes) were used. Unilateral OHT was induced by laser photocoagulation in KO and WT mice after anesthesia. A simultaneous recording of PERG was performed by homemade electrodes. Intraocular pressure (IOP) was measured with an IcareLAB rebound tonometer every day at noon before and after surgery. The data was analysed by ANOVA and t test. RESULTS: In AQP4 KO mice, the mean P50 and P95 amplitudes were significantly (P < 0.01) reduced compared with WT mice [P50: KO: (5.53 ± 1.31) vs WT: (8.14 ± 1.24) µv t = 5.70 and P95: KO: (7.71 ± 1.89) vs WT: (11.30 ± 2.61) µv, t = 3.83, respectively]. The latencies of AQP4 KO mice in both P50 and N95 were shorter than those of WT (t = 5.70 and t = 3.83 respectively, P < 0.01). The mean IOP was significantly (P < 0.05) increased after photocoagulation in AQP4 KO and WT mice compared with pre-photocoagulation [KO post: (14.78 ± 1.80) mm Hg(1 mm Hg = 0.133 kPa) vs KO pre-photocoagulation: (6.61 ± 0.90) mm Hg and WT post: (16.44 ± 1.46) mm Hg vs WT pre-photocoagulation: (7.31 ± 0.98) mm Hg, respectively] with animals under general anesthesia. IOP was lowered mildly but significantly in KO mice when compare with WT mice (t = 3.09, P < 0.05) lasting seven days. IOP was gradually decreased to baseline values at day eight in both of KO and WT mice. CONCLUSIONS: Our results indicate that AQP4 null may damage retinal function that can be detected by the measurement of PEGR, a sensitive parameter to reflect the function of RGC.

[The effect of AQP4 gene on the activation of retinal glial cells in chronic high intraocular pressure mice].

OBJECTIVES: To investigate whether aquaporin 4 (AQP4) gene can affect the activation of glial cells and cause the injury of retina of chronic high intraocular pressure mice models, and to discuss its possible mechanism. METHODS: Experimental study. The chronic high intraocular pressure models were established by burning the scleral venous of the right eye, which as the experiment group, and the left eye without any treatment as the control group. The intraocular pressure (IOP) was measured by rebound tonometer. Selected each of the successful model of chronic high intraocular pressure male AQP4 knockout mice (AQP-/-) and their wild-type (WT) male mice 40, divided the two type of mice into five groups after scleral venous burn according to the time of establishing models (24 h, 3 d, 1 w, 2 w, 4 w after scleral venous burn), 8 mouse in each group. And then producing the paraffin sections of mouse eye. Immunohistochemical staining methods was used to observe the expression of the glial fibrillary acid protein (GFAP) in retina glial cells, and observe the expression of the AQP4 in the retina of the WT mouse. Image was acquired under the fluorescence microscopy. The intraocular pressure was analyzed by t-test. RESULTS: After scleral venous burn (24 h, 3 d, 1 w, 2 w, 4 w), there were significant difference (t = 6.66 - 18.08, all P value < 0.05) in the IOP of the AQP4-/- mice (11.30 ± 1.59, 11.20 ± 1.15, 10.60 ± 1.53, 10.75 ± 1.45, 10.45 ± 1.39) and WT mice (11.50 ± 2.56, 11.25 ± 1.65, 10.75 ± 1.33, 10.60 ± 1.33, 10.40 ± 1.19) between the experimental groups and control groups (6.60 ± 0.94, 6.35 ± 0.99, 6.55 ± 0.94, 6.45 ± 0.99, 6.50 ± 0.94 and 6.60 ± 1.05, 6.50 ± 0.89, 6.40 ± 1.09, 6.30 ± 1.13, 6.50 ± 1.05). Since 24 hours after the scleral venous burn, the expression of GAFP of the two type mice began to increase and reached to peak at 1 week after burning. This peak of WT mice was more obvious than that of AQP4-/- mice. The concentration of GAFP began to decrease at 2 weeks after burning and reached to bottom at 4 weeks later. To the WT mice, the expression of AQP4 was remarkable higher in experimental group than that in control group at 1 week after the scleral venous burn. The expression of AQP4 was related to the expression of GAFP in high intraocular pressure of WT mice at 1 w, 2 w, and 4 w after the scleral venous burn. CONCLUSIONS: The chronic high intraocular pressure models can be established successfully by burning the scleral venous. AQP4 gene can affect the activation of the glial cells in chronic high intraocular pressure mice and lead to the injury of retina.

Induction and mechanism of apoptosis by hydroxycamptothecin in human Tenon's capsule fibroblasts.

PURPOSE: We investigated apoptosis induced by hydroxycamptothecin (HCPT) in human Tenon's capsule using fibroblasts cultured from human Tenon's capsule (HTFs), and the mechanism of induction. METHODS: HTFs were treated with 0-4 mg/L HCPT for 24 hours. Cell proliferation was measured by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay, and apoptotic cells were analyzed by Hoechst 33258 stain. The mRNA and protein levels of caspase-3, -8, and -9 were detected by RT-PCR and Western blotting. RESULTS: By MTT assay, HCPT induced apoptosis in HTFs in a concentration- and time-dependent manner. Hoechst 33258 staining and transmission electron microscopy showed typical apoptotic morphology, such as condensed chromatin, irregular nuclei, and apoptotic body formation. The mRNA and protein levels of caspase-3 and caspase-9 were upregulated, while caspase-8 was unchanged. Z-VAD-FMK, a caspase inhibitor, inhibited the apoptosis of fibroblasts induced by HCPT. The expression levels of caspase-3 and caspase-9 were down-regulated after Z-VAD-FMK treatment. CONCLUSIONS: Caspase-3 and caspase-9 are important elements in regulating HCPT-induced apoptosis in HTFs.