Quantitative analysis of dynamic iris changes in primary angle-closure disease with long axial lengths: the Handan Eye Study.

OBJECTIVE: To investigate dynamic iris changes in patients with primary angle-closure disease (PACD) with long axial length (AL) compared to those with short and medium AL. METHODS: This observational cross-sectional study enrolled participants aged 35 years or older from the Handan Eye Study follow-up examination who were diagnosed with PACD and underwent Visante anterior segment optical coherence tomography (ASOCT) imaging under light and dark conditions. The right eye of each participant was included in the analysis. AL was categorized as short (<22.0 mm), medium (≥22.0 to ≤23.5 mm), or long (>23.5 mm). Anterior segment parameters, including iris dynamic changes, were compared among the three groups with different ALs. RESULTS: Data from 448 patients with PACD were analyzed. We found that 10.9% of included eyes had a long AL with a flatter cornea; larger central anterior chamber depth, angle opening distance, anterior chamber width, anterior chamber area, and volume; and smaller lens thickness and lens vault (LV) (P < 0.05) than those with short AL. No significant difference existed between the three groups in iris thickness, iris cross-sectional area (IA), iris curvature, or pupil diameter (PD) change between light and dark (P > 0.05). The significant associated factors for IA changes were area recess area (ARA) in the dark, LV in the dark, and PD change from light to dark (P < 0.05). CONCLUSIONS: Dynamic and static iris parameters were consistent across patients with PACD with short, medium, or long AL and may contribute to the pathogenesis of angle closure in atypical PACD.

Anterior segment measurements and determinants of angle width with short, medium, and long axial lengths in a rural Chinese population.

Purpose: To report the anterior segment measurements and investigate the determinants of angle width with short, medium, and long axial length (AL) in a rural Chinese population. Design: Observational, population-based, cross-sectional study. Methods: Subjects aged ≥35 years who underwent complete ocular examinations during the follow-up of the Handan Eye Study were included. Ocular data of the right eye were analyzed. Anterior segment parameters were obtained and stratified by age and sex. AL was categorized into short (<22.0 mm), medium (22.0-23.5 mm), and long (>23.5 mm) subgroups. Linear regression analyses were performed to identify the parameters associated with angle width (angle opening distance at 500 µm from the scleral spur (SS) [AOD500]). Results: The final analysis included 4435 subjects (58.0 [49.0, 64.0] years old, 44.1% males). Smaller AOD500 was significantly associated with female sex (P = 0.032), larger iris thickness at 750 µm from the SS (IT750) (P < 0.001), larger lens vault (LV) (P < 0.001), and smaller anterior chamber volume (ACV) (P < 0.001) in the short AL subgroup; larger sphere equivalent (SE), IT750, iris curvature (IC), and LV and smaller ACV (all P < 0.001) in the medium AL subgroup; and larger SE, IT750, IA, IC, and LV and smaller ACV (all P < 0.001) in the long AL subgroup. Conclusions: Our study provides the anterior segment parameters of a large rural Chinese population. IT750, ACV, and LV were found to be the most important factors associated with angle width.

Anterior Segment Characteristics and Risk Factors for Primary Angle Closure Disease With Long Axial Lengths: The Handan Eye Study.

Purpose: To investigate the anterior segment characteristics of primary angle closure disease (PACD) with long axial length (AL) compared with that of those with short and medium AL and explore the risk factors associated with AC with different AL levels. Methods: This observational cross-sectional study enrolled subjects aged 35 years or older who completed the follow-up examinations of the Handan Eye Study and dichotomized them into normal and PACD groups. Ocular data of the right eye were analyzed. AL was categorized into short (<22.0 mm), medium (22.0-24.0 mm), or long (>24.0 mm) subgroups. Demographic and anterior segment parameters of PACD subjects were compared between the three AL subgroups. Logistic regression analysis was performed to identify the risk factors for PACD in the three subgroups. Results: Data from 715 PACD and 1446 normal subjects were analyzed. Only 6.6% of the PACD eyes had long AL, with lower spherical equivalent, larger anterior chamber depth (P < 0.001), and smaller lens thickness (P < 0.001) than those with short and medium AL. No significant differences were found for angle opening distance and iris parameters on comparing the values of eyes with long AL with that of those with short and medium AL. Significant risk factors for the development of PACD with long AL were peripheral iris thickness, anterior chamber width, and lens vault. Conclusions: PACD with long AL was uncommon. A thicker peripheral iris, larger lens vault, and smaller ACW contributed to angle closure in these patients.

Five-year incidence of primary glaucoma and related risk factors - The Handan eye study.

PURPOSE: To determine the 5-year incidence of primary glaucoma and its associated risk factors in rural northern China. METHODS: Population-based cohort study. A total of 5184 participants aged 30 years and older, without glaucoma at baseline, were subjected to comprehensive standardized interviews and ophthalmic and systemic examinations at baseline and after a 5-year interval in the Handan Eye Study. Incident glaucoma was diagnosed by a consensus panel of five senior glaucoma specialists. Univariate and multivariable logistic regression analyses were performed to identify the baseline risk factors that could predict the incidence of glaucoma. RESULTS: During the 5-year follow-up, incident primary glaucoma developed in 82 subjects (1.6%; 95% confidence interval [CI], 1.2%-1.9%). The age- and gender-standardized incidence of glaucoma among subjects ≥40 years old was 2.1% (0.4% annually), calculated according to the 2010 Chinese census. A higher age (odds ratio [OR], 1.06; 95% CI, 1.04-1.09; p < 0.001), higher intraocular pressure (IOP) (OR, 1.11; 95% CI, 1.02-1.20; p = 0.017), and vertical cup disc ratio (VCDR) ≥ 0.60 (OR, 5.30; 95% CI, 3.22-8.73; p < 0.001) were found to be associated with an increased risk of incident glaucoma. For each year, older age and each mmHg higher IOP, the risks of primary glaucoma increased by 1.2% and 2.0% per year, respectively. CONCLUSION: We reported the 5-year incidence of primary glaucoma in a rural Chinese population and found that older age, higher IOP, and VCDR ≥ 0.60 at baseline could help in identifying those at highest risk of disease development.

Development of angle closure and associated risk factors: The Handan eye study.

PURPOSE: To investigate the development of angle closure from baseline open angle and associated risk factors in a rural Chinese population through a longitudinal study over a 5-year period. METHODS: Subjects aged ≥30 years and older with bilateral open angles at baseline of the Handan Eye Study who participated in the follow-up and had undergone both baseline and follow-up gonioscopic examinations were included. Subjects with any form of angle closure, glaucoma, incisional ocular surgery or other conditions that could influence the results were excluded. The development of angle closure was defined as the presence of primary angle closure suspect (PACS) or primary angle closure (PAC)/primary angle closure glaucoma (PACG) during the follow-up in normal subjects with baseline bilateral open angles. Logistic regression was performed to identify the baseline risk factors for the development of angle closure. RESULTS: A total of 457 subjects with bilateral open angles at baseline aged 53.0 (45.5, 58.0) years were enrolled. 94.7% of the included cases developed PACS, 5.3% developed PAC and no one developed PACG after 5 years. In logistic regression, significant risk factors for the development of angle closure were shallower central anterior chamber depth (ACD) (p = 0.002) and narrower mean angle width (p < 0.001). CONCLUSIONS: This study reports the development from baseline open angle to angle closure after a 5-year follow-up. We confirm that the mean angle width and central ACD were independent predictive risk factors for the development of any form of angle closure.

Association of Hypertriglyceridemia and Incident Glaucoma in a Rural Chinese Population: The Handan Eye Study.

Purpose: The purpose of this paper was to investigate the association between baseline metabolic risk factors and incident glaucoma over a 5-year period in rural Chinese adults. Methods: Population-based prospective cohort study. Participants aged 30 years and older without glaucoma at baseline who underwent comprehensive examinations at baseline and after a 5-year interval in the Handan Eye Study were enrolled. Incident glaucoma was defined as people without glaucoma in either eye at baseline that had developed glaucoma in at least one eye in the 5-year follow-up. Five metabolic syndrome components, mean blood pressure, fasting plasma glucose, total cholesterol, triglycerides (TGs), low density lipoprotein cholesterol, high-density lipoprotein cholesterol, and obesity, determined as body mass index ≥30 kg/m2 at baseline were considered as potential metabolic risk factors for incident glaucoma. Univariate and multivariate logistic regression analyses were carried out to determine baseline metabolic risk factors associated with incident glaucoma. Results: A total of 5184 participants were included in our study. During the 5-year follow-up, incident glaucoma developed in 82 subjects. Age (odds ratio [OR] = 1.060, 95% confidence interval [CI] = 1.034, 1.086, P < 0.001) and TGs level (OR = 1.213, 95% CI = 1.030, 1.429, P = 0.021) were independently and positively associated with incident glaucoma. Conclusions: Our study revealed that increased age and high TGs level, one of the baseline metabolic features, were independent risk factors for incident glaucoma. The data implied that the metabolic features be involved in the pathogenesis of glaucoma. Translational Relevance: This study shed the light on that the TGs level was involved in the pathogenesis of glaucoma.

Progression of Primary Angle Closure Suspect to Primary Angle Closure and Associated Risk Factors: The Handan Eye Study.

Purpose: To investigate the progression of angle closure from primary angle closure suspect (PACS) and associated risk factors over five years in rural Chinese adults. Methods: In this population-based cohort study, subjects aged ≥30 years old with unilateral or bilateral PACS at baseline of the Handan Eye Study who participated in the follow-up and had undergone baseline and follow-up gonioscopic examinations were included. The progression of angle closure was defined as the presence of primary angle closure (PAC)/primary angle-closure glaucoma (PACG) during the follow-up in subjects with PACS at baseline. Ocular data from the right eye were used for cases with bilateral PACS and unilateral PACS in the right eye at baseline. For those with unilateral PACS in the left eye at baseline, ocular data from the left eye were used. Demographic information, ocular conditions, personal history, and systemic comorbidities were compared between the progression and nonprogression groups. Univariate and multivariate logistic regression was performed to identify the baseline risk factors for progression of angle closure. Results: In total, 526 subjects (111 male, 415 female) with baseline PACS were finally enrolled. The overall progression of PACS to angle closure was 32 cases (31 PAC, 1 PACG). Logistic regression analysis identified narrower mean angle width (P < 0.001) to be associated with the progression. Conclusions: We report the progression from baseline PACS to PAC/PACG after five years. And baseline mean angle width was determined to be independent predictive risk factor for the progression of angle closure.

Detection of primary angleclosure suspect with different mechanisms of angle closure using multivariate prediction models.

PURPOSE: We had found that a multivariate prediction model used for the detection of primary angle-closure suspects (PACS) by combining multiple static and dynamic anterior segment optical coherence tomography (ASOCT) parameters had an area under the receiver operating characteristic curve (AUC) of 0.844. We undertook this study to evaluate this method in screening of PACS with different dominant mechanisms of angle closure (AC). METHODS: The right eyes of subjects aged ≥40 years who participated in the 5-year follow-up of the Handan Eye Study and had undergone gonioscopy and ASOCT examinations under light and dark conditions were included. All ASOCT images were analysed by the Zhongshan Angle Assessment Program. The dominant AC mechanism in each eye was determined to be pupillary block (PB), plateau iris configuration (PIC) or thick peripheral iris roll (TPIR). Backward logistic regression (LR) was used for inclusion of variables in the prediction models. LR, Naïve Bayes' classification (NBC) and neural network (NN) were evaluated and compared using the AUC. RESULTS: Data from 796 subjects (413 PACS and 383 normal eyes) were analysed. The AUCs of LR, NBC and NN in the PB group were 0.920, 0.918 and 0.917. The AUCs of LR, NBC and NN in the PIC group were 0.715, 0.708 and 0.707. The AUCs of LR, NBC and NN in TPIR group were 0.867, 0.833 and 0.886. CONCLUSIONS: Prediction models showed the best performance for detection of PACS with PB mechanism for AC and have potential for screening of PACS.

Establishment and Comparison of Algorithms for Detection of Primary Angle Closure Suspect Based on Static and Dynamic Anterior Segment Parameters.

Purpose: To establish and evaluate algorithms for detection of primary angle closure suspects (PACS), the risk factor for primary angle closure disease by combining multiple static and dynamic anterior segment optical coherence tomography (ASOCT) parameters. Methods: Observational, cross-sectional study. The right eyes of subjects aged ≥40 years who participated in the 5-year follow-up of the Handan Eye Study, and underwent gonioscopy and ASOCT examinations under light and dark conditions were included. All ASOCT images were analyzed by Zhongshan Angle Assessment Program. Backward logistic regression (BLR) was used for inclusion of variables in the prediction models. BLR, naïve Bayes' classification (NBC), and neural network (NN) were evaluated and compared using the area under the receiver operating characteristic curve (AUC). Results: Data from 744 subjects (405 eyes with PACS and 339 normal eyes) were analyzed. Angle recess area at 750 µm, anterior chamber volume, lens vault in light and iris cross-sectional area change/pupil diameter change were included in the prediction models. The AUCs of BLR, NBC, and NN were 0.827 (95% confidence interval [CI], 0.798-0.856), 0.826 (95% CI, 0.797-0.854), and 0.844 (95% CI, 0.817-0.871), respectively. No significant statistical differences were found between the three algorithms (P = 0.622). Conclusions: The three algorithms did not meet the requirements for population-based screening of PACS. One possible reason could be the different angle closure mechanisms in enrolled eyes. Translational Relevance: This study provides a promise for basis for future research directed toward the development of an image-based, noncontact method to screen for angle closure.

Design, methodology, and preliminary results of the follow-up of a population-based cohort study in rural area of northern China: Handan Eye Study.

BACKGROUND: Handan Eye Study (HES), a large population-based cohort study in rural area of northern China, was one of the few studies focusing on the major eye diseases of rural Chinese population. The aim of this study was to introduce the design, methodology and to assess the data quality of the follow-up phase of HES. METHODS: All participants were recruited in Yongnian county of Handan city between 2012 and 2013. Main outcomes were measured by visual quality scales and ocular examinations. We performed the Chi-square test to make comparison of categorical data among groups, One-way analysis of variance and Kruskal-Wallis test was applied to make comparison of continuous data among groups, a post-hoc test was done to make further pairwise comparison. Inter-class correlation coefficients (ICCs) and Kappa coefficients were used to evaluate the consistency between different operators. Logistic regression was used to explore the influence factors of death, odds ratio (OR) and 95% confidence interval (CI) were used to estimate the effect size of each influence factor. RESULTS: The follow-up rate was 85.3%. Subjects were classified into three groups: the follow-up group (n = 5394), the loss to follow-up group (n = 929), and the dead group (n = 507), comparison of their baseline information was done. Compared with the other two groups, age of the dead group (66.52 ±â€Š10.31 years) was the oldest (Z = 651.293, P < 0.001), male proportion was the highest (59.0%) (χ = 42.351, P < 0.001), only 65.9% of the dead finished middle school education (Z = 205.354, P < 0.001). The marriage percentage, body mass index (BMI), best-corrected visual acuity (BCVA), and intra-ocular pressure of the dead group was the lowest either. Spherical equivalent error (SER) of the dead group was the highest. Besides, history of smoking, hypertension, diabetes, and heart disease were more common in the dead group. Multivariate analysis showed that age (OR = 1.901, 95% CI: 1.074-1.108), gender (OR = 0.317, 95% CI: 0.224-0.448), and BCVA (OR = 0.282, 95% CI: 0.158-0.503) were associated with death. While between the follow-up group and the loss to follow-up group, there was only difference on age, gender, BMI, systolic blood pressure and SER. The Cronbach coefficients of all scales used in the follow-up were ≥0.63 and the cumulative variances were ≥0.61, indicating good reliability and validity. The ICCs and Kappa coefficients between different operators were ≥0.69. CONCLUSIONS: HES has a high follow-up rate and a low risk of loss to follow-up bias. Age, gender, and BCVA are influence factors of death. Specifically, male subjects are at a higher risk of death than female, age is a risk factor of death while BCVA is a protective factor for death.

Dynamic Iris Changes as a Risk Factor in Primary Angle Closure Disease.

PURPOSE: We studied the association between dynamic iris changes and the spectrum of primary angle closure disease (PACD), using the anterior segment optical coherence tomography (ASOCT). METHODS: Eligible primary angle closure (PAC), primary angle closure glaucoma (PACG), age, and sex comparable primary angle closure suspects (PACS) and normal subjects from the 5-year follow-up of the Handan Eye Study underwent ASOCT testing in dark and light conditions. The right eye of each subject was analyzed and biometric parameters including iris cross-sectional area (IA), lens vault (LV), pupil diameter (PD), and centroid-to-centroid distance (CCD) were calculated using the Zhongshan Angle Assessment Program. RESULTS: Totals of 31 PACS, 31 PAC/PACG, and 31 normal eyes were eligible for analysis. Loss of IA per mm PD increase in the dark compared to light was 0.18 mm in PACS, 0.13 mm in PAC/PACG, and 0.24 mm in normal (P = 0.015 between groups) groups. Diagnoses of normal (P = 0.001) and a smaller PD in light (P = 0.003) were statistically significant determinants of a larger IA loss per mm PD increase in the dark compared to light. Logistic regression analysis showed that LV (P = 0.002) and IA loss per mm PD increase (P = 0.017) were risk factors for an occludable angle. CONCLUSIONS: Significant differences in iris behavior in the dark compared to light in PACS, PACD, and normal eyes add to the evidence that dynamic iris change has a role in the pathogenesis of PAC in a rural Chinese population.

A Population-based Investigation of Circadian Rhythm of Intraocular Pressure in Habitual Position Among Healthy Subjects: The Handan Eye Study.

PURPOSE: (1) To investigate the reference value of peak-trough difference in circadian rhythm of intraocular pressure (IOP) in habitual position and (2) to compare the IOP parameters among 3 age groups. MATERIALS AND METHODS: Habitual IOP of healthy subjects sampled from the population in the Handan Eye Study was measured every 2 hours in the seated position during light-wake period (7:30 AM, 9:30 AM, 11:30 AM, 1:30 PM, 3:30 PM, 5:30 PM, 7:30 PM, 9:30 PM) and in the supine position during dark-sleep period (11:30 PM, 1:30 AM, 3:30 AM, 5:30 AM). Blood pressure and heart rate were obtained subsequently at each IOP measurement. RESULTS: Two hundred six healthy subjects were included in the final analyses (n=20, 30 to 39 y old; n=95, 40 to 49 y old; n=91, 50 to 59 y old). For peak-trough difference (7.2±2.3 mm Hg; 6.8 to 7.5 mm Hg, 95% confidence interval) in habitual position, the reference value was described as median 7.0 mm Hg, 25th percentile 5.5 mm Hg, and 95th percentile 11.5 mm Hg. No significant differences in peak-trough difference, acrophase (cosine-fit analysis derived peak timing) and amplitude (half distance between the cosine-fit maximum and minimum) were found among the 3 age groups. In the cosine model, the nocturnal acrophase (3:49±0.53 AM; 3:42 to 3:55 AM, 95% confidence interval) was detected for the entire group. Furthermore, 106 subjects (52%) had a nocturnal peak pattern, 36 subjects (17%) had a diurnal peak pattern, and 64 subjects (31%) had no evident pattern. CONCLUSIONS: In habitual position, 75% of healthy subjects from a population-based investigation had IOP variation >5.5 mm Hg and 95% subjects had <11.5 mm Hg variation. Aging may not influence the circadian habitual IOP rhythm.

Quantitative analysis of iris changes following mydriasis in subjects with different mechanisms of angle closure.

PURPOSE: We estimate and compare change in iris cross-sectional area (IA) after physiologic and pharmacologic mydriasis in subjects with different dominant mechanisms for primary angle closure. METHODS: Anterior segment optical coherence tomography (AS-OCT) measurements in light, dark, and following pharmacologic dilation were obtained on primary angle closure suspects (PACS), primary angle closure (PAC), and primary angle closure glaucoma (PACG) examined during the 5-year follow-up of the Handan Eye Study. Subjects were categorized into three subgroups according to their dominant angle closure (AC) mechanisms as determined by AS-OCT: pupillary block (PB), plateau iris configuration (PIC), and thick peripheral iris roll (TPIR). The IA and other biometric parameters measured using the Zhongshan Angle Assessment Program in the right eyes of all subjects were analyzed. RESULTS: A total of 364 right eyes of subjects with PACS (333), and PAC/PACG (31) was included in the analysis. Significant differences in the change of IAs (P = 0.030), IA loss per mm pupil diameter (PD) increase (P = 0.001) in light versus pharmacologic dilation, and IA loss per mm PD increase (P = 0.011) from dark versus pharmacologic dilation were observed among the three groups. The smallest decrease occurred in the PB group. CONCLUSIONS: There are significant differences in IA and IA loss per mm of pupil change following physiologic or pharmacologic mydriasis in Chinese subjects with dissimilar dominant mechanisms for AC. Dynamic iris change may have a more important role in angle closure where PB is the dominant mechanism.

The Handan Eye Study: comparison of screening methods for primary angle closure suspects in a rural Chinese population.

OBJECTIVE: To evaluate the van Herick test, anterior segment optical coherence tomography (AS-OCT), Pentacam and scanning peripheral anterior chamber depth analyzer (SPAC) for detecting primary angle-closure suspect (PACS) in a rural Chinese population. METHODS: Eligible subjects aged ≥40 years were examined at the 5-year follow-up of the Handan Eye Study. PACS was defined as non-visibility of the posterior pigmented trabecular meshwork for ≥180° of the angle. Sensitivity, specificity, predictive values and receiver operating characteristic curves were used to assess the tests. RESULTS: A total of 425 right eyes of 431 eligible subjects were analyzed. The area under the curve (AUC) for the van Herick test and AS-OCT were 0.711 and 0.799, respectively. The AUC for Pentacam anterior chamber depth was 0.834, while anterior chamber angle and anterior chamber volume had AUCs of 0.680 and 0.800, respectively. The AUC for SPAC was 0.779. AS-OCT had a specificity of 87% with a sensitivity of 73%. The best specificity of 92% (sensitivity 19%) was achieved by the van Herrick test at the 15% cut-off. CONCLUSIONS: None of the tests evaluated achieved the combination of specificity and sensitivity needed for population-based screening and their current capability does not realize the objective of case detection in the setting of an ophthalmology clinic.

Quantitative analysis of iris changes after physiologic and pharmacologic mydriasis in a rural Chinese population.

PURPOSE: To estimate and compare the change in iris cross-sectional area (IA) and iris volume (IV) following physiologic and pharmacologic pupil dilation in primary angle closure suspects (PACS) and normal subjects. METHODS: Anterior segment-optical coherence tomography (AS-OCT) measurements in light, dark, and following pharmacologic dilation were obtained on 186 PACS and 224 normal subjects examined during the 5-year follow-up of the Handan Eye Study. Iris cross-sectional area, IV, and other biometric parameters calculated using the Zhongshan angle assessment program in the right eyes of all subjects were analyzed. RESULTS: The mean IA and IV decreased in dark compared with light and after pharmacologic dilation in both PACS and normal eyes. This change was statistically significant in normal eyes: light versus pharmacologic dilation for IA (P = 0.038) and for IV, both light versus dark (P = 0.031) and light versus pharmacologic dilation (P = 0.012). A longer axial length (P = 0.028) and a greater change in pupil diameter (PD) (P < 0.001) were associated with a larger decrease of IA for the light to dark comparison. A diagnosis of normal eyes (P = 0.011), larger PD in dark (P = 0.001), and a larger change in PD (P = 0.001) were associated with a larger decrease of IV from light to dark. CONCLUSIONS: The differences in iris behavior between PACS and normal rural Chinese subjects following physiologic or pharmacologic pupillary dilation may help provide insights into the pathogenesis of angle closure.

Can intraoperative intraocular pressure during primary trabeculectomy predict early postoperative pressure?

PURPOSE: To study the association of intraoperative intraocular pressure (IOP) at the conclusion of primary trabeculectomy with postoperative IOP on days 1, 7, and 30 and report the ability of intraoperative IOP to predict early postoperative IOP. PATIENTS AND METHODS: Prospective, observational, case series. Ninety-seven consecutive patients with primary open-angle or angle-closure glaucoma underwent primary trabeculectomy. The IOP was measured 3 minutes after the closure of scleral flap with a formed anterior chamber. Clinical details and complications were recorded over a 30-day follow-up. The patients were grouped as A (intraoperative IOP≤10.0 mm Hg), B (>10, ≤15.0 mm Hg), and C (>15 mm Hg). RESULTS: Mean age was 60.8±9.9 years. Forty (41.3%) patients were males. Eighty-two (84.5%) had primary angle-closure glaucoma. Mitomycin-c (MMC) was used in 75 (77.3%) eyes. Mean IOP in group C was significantly higher than group A at all visits (P=0.005, 0.002, and 0.05). Postoperative IOP was associated with intraoperative IOP, age, duration, and dose of MMC in univariable regressions. On multivariable analysis, the intraoperative IOP was associated with postoperative IOP's on day 1 (regression coefficient b=0.24, P=0.039, R(2)=0.24) and day 7 (b=0.47, P<0.001, R=0.42), but not on day 30 (b=0.22, P=0.065, R(2)=0.12). IOP on day 7 was predicted by -8.6+0.47×(intraoperative IOP)+0.27×age-11.7×(dose of MMC in mg/mL). Prediction for day 30=9.8+0.27×(intraoperative IOP). CONCLUSIONS: In patients undergoing uncomplicated primary trabeculectomy, intraoperative IOP is associated with and may predict early postoperative IOP. Adjusting the IOP during the operation may optimize postoperative IOP.

Baseline characteristics of nearwork-induced transient myopia.

PURPOSE: The purpose of the present study was to describe the baseline refractive and nearwork-induced transient myopia (NITM) characteristics of the Beijing Myopia Progression Study, a 3-year cohort study, that has three overall specific aims: to investigate the natural history of NITM in schoolchildren living in the inner city of Beijing aged between 7 and 17 years; to investigate the possible relation between NITM and permanent myopia; and to determine the possible associations with NITM (eg, parental history). METHODS: Three hundred eighty-six students (187 males and 199 females) were enrolled. The mean ages were 8.4 ± 1.1 years and 14.2 ± 1.6 years for the primary school and secondary school students, respectively. Baseline refractive aspects were determined clinically. Initial NITM and its decay were assessed objectively immediately after binocularly viewing and performing a sustained near task (5 minutes; 5 diopters [D]), incorporating a cognitive demand with full distance refractive correction in place. RESULTS: Initial NITM (mean ± SD) / decay time (median, first quartile, and third quartile) was 0.18 ± 0.16 D / 50 (20, 90) seconds, 0.09 ± 0.13 D / 30 (10, 40) seconds, and 0.10 ± 0.19 D / 20 (10, 40) seconds among the myopic, emmetropic, and hyperopic students, respectively, for the combined school levels. Initial NITM and decay time were significantly larger/longer in the myopic versus the other two refractive groups. CONCLUSIONS: The present findings demonstrate that in a large sample of school-aged children with myopia, the initial NITM magnitude was significantly larger and the decay duration was significantly longer than that observed in age-matched children with either emmetropia or hyperopia. Follow-up for the next 3 years will provide insight into the possible role of NITM in the development of permanent myopia.

[Physical exercise and intraocular pressure].

In the 1960s, it had been observed that physical exercises could reduce the intraocular pressure (IOP) in patients with glaucoma. However, the effect of IOP reduction varied with exercise type and intensity, as well as the duration after exercise. Difference of lowering the IOP in glaucoma patients and healthy people were also observed. The mechanisms of reducing the IOP by exercise were very complicated and believed to be associated with the lower concentration of norepinephrine, the rising of colloid osmotic pressure, the co-action of nitric oxide and endothelin after exercise, and also related to the gene polymorphism of ß2-adrenergic receptor. Physical exercise, such as jogging, walking and bicycle riding, could be suggested as a complimentary therapy in addition to the pharmaceutical and surgical therapies available for glaucoma patients, even though the mechanism for lowering IOP is not clear enough.

Long-term intraocular pressure fluctuation of primary angle closure disease following laser peripheral iridotomy/iridoplasty.

BACKGROUND: Many studies indicated that short-term and long-term intraocular pressure (IOP) fluctuations in primary open angle glaucoma patients might lead to glaucomatous progression. However, seldom study has evaluated the long-term fluctuation of IOP in primary chronic angle closure diseases. The objective of this study was to investigate the long-term IOP fluctuation of primary angle closure diseases and its associations following laser peripheral iridotomy (LPI) with or without laser peripheral iridoplasty. METHODS: A total of 158 patients with primary angle closure suspect (PACS, n = 21), primary angle closure (PAC, n = 81) and primary angle closure glaucoma (PACG, n = 55) had been treated by LPI with or without laser peripheral iridoplasty and followed up for more than 12 months. IOP was measured with Goldman applanation tonometer. Multivariate linear regression with generalized estimating equation (GEE) regression models was used to evaluate the association of long-term IOP fluctuation (maximum IOP minus minimum IOP) with gender, age, baseline IOP, baseline peripheral anterior synechia (PAS), baseline vertical cup/disc ratio (VCDR), baseline mean deviation (MD), need for IOP-lowering medications. RESULTS: IOP fluctuation during follow-up in PACS, PAC and PACG groups were (4.83 ± 2.90), (5.67 ± 3.35), and (9.40 ± 7.14) mmHg, respectively. IOP fluctuation was strongly correlated with baseline IOP (r = 0.356, P < 0.001), PAS (r = 0.374, P < 0.001). IOP fluctuation was higher in patients with higher baseline IOP (0.18 mmHg per unit increase, 95%CI: 0.05 - 0.31 mmHg). CONCLUSIONS: Long-term IOP fluctuation in PACG group was larger than that in PACS or PAC group. Eyes with higher baseline IOP were observed to have larger long-term IOP fluctuation.

[Alteration of anterior chamber and angle structure in eyes with primary angle closure after laser peripheral iridotomy].

OBJECTIVE: To quantitatively evaluate the long-term changes in anterior segment morphology by using ultrasound biomicroscopy (UBM) after laser peripheral iridotomy (LPI) in eyes with primary angle closure (PAC). METHODS: This was a clinical case series study. A total of 54 eyes with PAC of 31 consecutive patients were enrolled. Routine ophthalmic and UBM examination were performed at visit one (before LPI), 2 weeks, 6, and 12 months after LPI. The parameters of anterior chamber were measured by UBM and calculated. Results of each follow-up time were analyzed using repeated measures analysis of variance. Parameters of UBM measurement at 750 µm anterior to the sclera spur and at 500 µm counterpart were compared using paired student t-test. RESULTS: Compared to before LPI, anterior chamber depth (ACD) was deepened by approximate 0.10 mm after LPI, however, it was not statistically significant (F = 3.50, P > 0.05). Angle opening distance (AOD), trabecular-iris angle (TIA), angle recess area (ARA) and trabecular-ciliary process distance (TCPD) were significantly increased at 2 weeks, 6 and 12 months after LPI compared with respective baseline [AOD750: (165.0 ± 70.3), (185.8 ± 68.5), (196.1 ± 77.7) µm vs (66.2 ± 51.6) µm, F = 92.60; TIA750: 14.1° ± 6.3°, 15.5° ± 6.2°, 16.4° ± 5.9° vs 6.4° ± 4.9°, F = 92.60; ARA: (0.058 ± 0.024), (0.065 ± 0.023), (0.068 ± 0.026) mm(2) vs (0.025 ± 0.017) mm(2), F = 92.60; TCPD: (647.1 ± 113.0), (701.8 ± 93.4), (670.1 ± 95.4) µm vs (571.0 ± 97.2) µm, F = 34.00; P < 0.05]. The parameters of UMB measurement at 750 µm were significantly increased more than that at 500 µm anterior to the sclera spur (AOD: t = 5.90, TIA750: t = 2.70, P < 0.05; ARA: t = 2.00, P = 0.05). CONCLUSIONS: LPI can significantly widen the peripheral anterior angle in eyes with PAC lasting for at least 1 year after LPI. Parameters detected by UBM at 750 µm anterior to the sclera spur appear to be more sensitive in evaluating the alternation of peripheral angle structure.