Macular thickness and its associated factors in a Chinese rural adult population: the Handan Eye Study.

PURPOSE: To describe the normal macular thickness and assess its associations. METHODS: The Handan Eye Follow-up Study was conducted between 2012 and 2013. Macular thickness was scanned by spectral-domain optical coherence tomography (OCT). The built-in software generated a retinal thickness (RT) map, which was divided into three regions (central, internal and external regions) and nine quadrants (one in central and four in internal and external regions each). RESULTS: For 5394 subjects in the Handan Eye Follow-up Study, 4793 received OCT examination, 2946 of whom (accounting for 61.46% of the total subjects, mean age 58.91±10.95, 55.6% were women) were included for analysis. The mean RT in central macula, inner and outer rings were (237.38 µm±23.05 µm), (309.77 µm±18.36 µm) and (278.29 µm±14.38 µm), respectively (overall difference, p＜0.001). In inner ring, the RT in temporal was thinnest, followed by nasal, superior and inferior. In outer ring, the RT in superior was thinnest, with the next subfields being temporal, inferior and nasal, respectively. The RT in central macula, inner and outer rings were significantly thicker in men than in women. Multivariate linear regression analysis showed that in central macula, RT increased in subjects younger than 60 years and thinned above the age of 60. In inner and outer rings, RT thinned along with age (p＜0.001). CONCLUSIONS: This study finds that RT in central macula is the thinnest, followed by the outer ring, the RT in the inner ring is the thickest. Age and gender are related to RT. These associated factors need to be considered when explaining RT.

Intraocular Pressure, Age, and Central Corneal Thickness in a Healthy Chinese Children Population: The Handan Offspring Myopia Study.

PURPOSE: To assess the distribution and factors related to intraocular pressure (IOP) in a Chinese children population in Northern China. METHODS: 1,238 offspring aged 6 to 18 years, residing in six villages, were recruited for this current study, the Handan Offspring Myopia Study. Participants underwent an interviewer-administered questionnaire and a complete ocular examination, including standardized measurement of IOP with Perkins applanation tonometry. RESULTS: 1,648 eyes of 828 children were included in the analysis. The mean IOP was 13.9 ± 1.6 mmHg. The mean IOP for the study population increased from 13.0 ± 1.5 mmHg for those 6 to 7 years of age to 14.2 ± 1.4 mmHg for those 15 years of age or older (P < .001). The mean central corneal thickness (CCT) was 548.7 ± 32.1 µm, and had no difference among different age groups and gender. In univariate regression analysis, age (0.12 mmHg per 1 year old), height (0.09 mmHg per 5 cm), weight (0.02 mmHg per kg), body mass index (0.07 mmHg per 1 m/kg2), systolic blood pressure (0.06 mmHg per 5 mmHg), CCT (0.06 mmHg per 5 µm), and SE (-0.11 mmHg per 1 D) were correlated with IOP. In multivariate regression analysis, higher IOP was only associated with older ages (p = .002) and thicker CCT (p = .001). CONCLUSION: The mean IOP in healthy rural Chinese children aged 6-18 years is about 14 mmHg, which is lower than in adults in the same locality. The mean IOP is slightly increasing with age during childhood, which is opposite to the result among adults. Age and CCT are the major independent factors associated with IOP.

Association of peripheral anterior synechia, intraocular pressure, and glaucomatous optic neuropathy in primary angle-closure diseases.

AIM: To investigate the association of peripheral anterior synechiae (PAS) with intraocular pressure (IOP) and glaucomatous optic neuropathy (GON) in primary angle closure (PAC) and primary angle-closure glaucoma (PACG). METHODS: Totally 355 eyes (238 PAC and 117 PACG) of 181 patients were included in this retrospective analysis of baseline data from a randomized clinical trial. All patients had undergone a comprehensive ophthalmic examination. The extent of PAS in clock hours as determined on gonioscopy was documented. The independent effect of the extent of PAS on IOP and the prevalence of GON were determined using multivariable generalized estimating equation (GEE) models. RESULTS: The frequency of GON increased with the extent of PAS and a higher IOP. PAS were more extensive (8 vs 1 clock hour, P<0.001) and IOP higher (28.01 vs 18.00 mm Hg, P<0.001) in PACG compared to PAC. The prevalence of GON among the PAS quartiles were 10.2% (PAS<0.5 clock hours), 16.9% (PAS≥0.5 and PAS<3 clock hours), 29.6% (PAS≥3 and PAS<7 clock hours), and 74.4% (PAS≥7 clock hours), respectively. After adjusting for IOP, age, gender, spherical equivalent, average Shaffer score and number of medications, the odds ratio (OR) for GON was 4.4 (95%CI: 1.5-13.0; P=0.007) with PAS≥3 clock hours and 13.8 (95%CI: 4.3-43.6; P<0.001) with PAS≥7 clock hours as compared to eyes with PAS<0.5 clock hours. The frequency of GON increased linearly with the extent of PAS. Extent of PAS was also associated with higher IOP. Eyes with both PAS≥6 clock hours and IOP≥21 mm Hg had the highest risk of GON compared to eyes with both PAS<6 clock hours and IOP<21 mm Hg (OR=18.0, 95%CI: 7.5-43.4; P<0.001). CONCLUSION: The extent of PAS in PAC and PACG is an important predictor of higher IOP and is linearly associated with GON independent of IOP, suggesting other factors related to PAS formation may be involved in the development of GON in PACG.

Progression rate to primary angle closure following laser peripheral iridotomy in primary angle-closure suspects: a randomised study.

AIM: To report the progression rate (PR) to primary angle closure (PAC) following laser peripheral iridotomy (LPI) in PAC suspects (PACS). METHODS: Prospective, randomized controlled interventional clinical trial conducted at the Handan Eye Hospital, China. Totally 134 bilateral PACS, defined as non-visibility of the posterior trabecular meshwork for ≥180 degrees on gonioscopy were randomly assigned to undergo LPI in one eye. Gonioscopy and Goldmann applanation tonometry were performed prior to, on day 7 and 12mo post LPI. RESULTS: Eighty of 134 patients (59.7%) could be followed up at one year. The mean intraocular pressure (IOP) in treated eyes was 15.9±2.6 mm Hg at baseline, 15.4±3.0 mm Hg on day 7; 16.5±2.9 mm Hg at one month, and 15.5±2.9 mm Hg at 12mo; the IOP in untreated eyes was similar (P=0.834). One or more quadrants of the angle opened in 93.7% of the LPI treated eyes, but 67.0% (53/79) remained closed in two or more quadrants. The PR to PAC in untreated eyes was 3.75% and one developed acute angle-closure glaucoma (AACG); the PR to PAC in treated eyes was 2.5% and none had developed peripheral anterior synechia (PAS) or AACG. CONCLUSION: LPI can open some of the occludable angle in the majority of eyes with PACS, but 67% continue to have non-visibility of the trabecular meshwork for over 180 degrees.

Factors associated with blindness three months following treatment for acute primary angle glaucoma.

AIMS: To study the risk factors associated with blindness after treatment of acute primary angle closure (APAC), and to identify the critical time window to decrease rate of blindness. METHODS: In this multicentre retrospective case series, 1030 consecutive subjects (1164 eyes) with APAC in China were recruited. The rates of blindness were analysed up to 3 months after treatment of APAC. A logistic regression was used to identify the risk factors associated with blindness, including age, gender, distance to hospital, rural or urban settings, treatment method, education level, time from symptom to treatment (TST, hours) and presenting intraocular pressure (IOP). The critical time window associated with a blindness rate of ≤1% was calculated based on a cubic function by fitting TST to the rate of blindness at each time point. RESULTS: The rate of blindness after APAC was 12.54% after treatment. In multivariate regression, education level, TST and presenting IOP were risk factors for blindness (p=0.022, 0.004 and 0.001, respectively). The critical time window associated with a blindness rate of ≤1% was 4.6 hours. CONCLUSIONS AND RELEVANCE: Education level, TST and presenting IOP were risk factors for blindness after APAC. Timely medical treatment is key in reducing blindness after APAC.

Near work, outdoor activity, and myopia in children in rural China: the Handan offspring myopia study.

BACKGROUND: The near work and outdoor activity are the most important environmental risk factors for myopia. However, data from Chinese rural children are relatively rare and remain controversial. Therefore, the purpose of this study was to evaluate the relationship of both near work and outdoor activities with refractive error in rural children in China. METHODS: In this cross-sectional study, 572 (65.1%) of 878 children (6-18 years of age) were included from the Handan Offspring Myopia Study (HOMS). Information from the parents on these children, as well as the parent's non-cycloplegic refraction, were obtained from the database of the Handan Eye Study conducted in the years 2006-2007. A comprehensive vision examination, including cycloplegic refraction, and a related questionnaire, were assessed on all children. RESULTS: The overall time spent on near work and outdoor activity in the children was 4.8 ± 1.6 and 2.9 ± 1.4 h per day, respectively. Myopic children spent more time on near work (5.0 ± 1.7 h vs.4.7 ± 1.6 h, p = 0.049), while no significant difference was found in outdoor activity hours (2.8 ± 1.3 h vs. 3.0 ± 1.4 h, p = 0.38), as compared to non-myopic children. In the multiple logistic analysis, in general, no association between near work and myopia was found after adjusting for the children's age, gender, parental refractive error, parental educational level, and daily outdoor activity hours [odds ratio (OR), 95% confidence interval (CI): 1.10, 0.94-1.27]. However, a weak protective effect of the outdoor activity on myopia was found (OR, 95% CI: 0.82, 0.70-0.96), after adjusting for similar confounders. CONCLUSIONS: In general, no association between near work and myopia was found, except for the high near work subgroup with moderate outdoor activity levels. A weak protective effect of outdoor activity on myopia in Chinese rural children was observed.

Laser Peripheral Iridotomy versus Trabeculectomy as an Initial Treatment for Primary Angle-Closure Glaucoma.

PURPOSE: To compare laser peripheral iridotomy (LPI) with trabeculectomy as an initial treatment for primary angle-closure glaucoma (PACG) with peripheral anterior synechiae (PAS) ≥ 6 clock hours. METHODS: Patients were drawn from two randomized controlled trials. 38 eyes of 38 patients (PAS ≥ 6 clock hours) were treated with LPI (group 1) while 111 eyes of 111 PACG patients (PAS ≥ 6 clock hours) underwent primary trabeculectomy (group 2). All patients underwent a comprehensive ophthalmic examination at baseline and at postoperative visits and were followed up for a minimum of one year. RESULTS: Group 2 had higher baseline IOP (45.7 ± 14.8 mmHg versus 34.3 ± 14.3 mmHg) than group 1 and more clock hours of PAS (10.4 ± 1.9 versus 9.0 ± 2.2). IOPs at all postoperative visits were significantly lower in group 2 than in group 1 (p = 0.000). Five eyes in group 1 required trabeculectomy. 17 of the 38 eyes in group 1 (44.7%) required IOP-lowering medications as compared to seven of the 111 eyes in group 2 (6.3%). Cataract progression was documented in 2 eyes (5.3%) in group 1 and 16 eyes (14.4%) in group 2. CONCLUSIONS: Primary trabeculectomy for PACG (PAS ≥ 6 clock hours) is more effective than LPI in lowering IOP.

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.

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.

Daytime fluctuation of intraocular pressure in patients with primary angle-closure glaucoma after trabeculectomy.

PURPOSE: To evaluate the daytime fluctuation of intraocular pressure (IOP) in patients with primary angle-closure glaucoma (PACG) after trabeculectomy. PARTICIPANTS AND METHODS: A total of 176 patients with PACG participated in a clinical trial of trabeculectomy with or without releasable sutures. Applanation IOP was measured at 5, 7, and 10 AM, and 2, 6, and 10 PM at 3 months posttrabeculectomy. We documented the mean, peak, and trough IOPs, determined the fluctuation of daytime IOP, and explored the associations of IOP fluctuation with baseline factors. RESULTS: IOP measurements were obtained in 173 patients. The mean daytime IOP was 13.2±3.7 mm Hg; mean peak IOP 15.1±4.1 mm Hg, mean trough IOP 11.3±3.5 mm Hg, and mean fluctuation 3.8±2.1 mm Hg. Fluctuation was positively correlated with peak (r=0.528, R2=0.28, P<0.001) and mean IOP (r=0.278, R2=0.08, P<0.001), but not with the trough IOP (r=0.015, P=0.843). Fluctuation was lower with extent of bleb (0.6 mm Hg/unit increase in extent; 95% CI, 0.1-1.2 mm Hg) and in blebs with microcysts (1.1 mm Hg less fluctuation; 95% CI, 0.2-1.9 mm Hg). Fluctuation was not associated with sex, age, baseline IOP, extent of peripheral anterior synechia or number of glaucoma medications before surgery, mean deviation of the visual field, vertical cup:disc ratio, or the use of releasable sutures. CONCLUSIONS: The mean fluctuation of daytime IOP after trabeculectomy for PACG was about 4 mm Hg. The fluctuation was positively associated with higher peak and mean IOP and negatively associated with extent of bleb and presence of microcysts.

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.

[Assess correlation between bleb morphology at long-term intraocular pressure effect in primary angle-closure glaucoma following trabeculectomy].

OBJECTIVE: To evaluate the correlation between morphologic appearance of blebs at 3 month and long-term intraocular pressure (IOP) effect in patients with primary angle-closure glaucoma (PACG) after trabeculectomy. METHODS: Multi-centered cases series. Data were collected from 176 patients aged ≥ 40 years with PACG who were participated in a randomized clinical trial that aimed at addressing the efficacy of augmented releasable sutures after trabeculectomy. The bleb morphology was graded using the Modified Indian Bleb Appearance Grading Scale (IBAGS) based on standard photos at 3 month after trabeculectomy. IOPs were measured with Goldmann applanation tonometer. The correlation between bleb components and other selected testing influencing factors and long-term IOP was tested by linear Logistic regression analysis. RESULTS: 150 patients (85.7%) completed 18 months of follow up. IOP was (15.6 ± 5.4) mm Hg at 18 month of post-operation. 135 eyes had an IOP ≤ 21 mm Hg without additional medications, 10 eyes ≥ 21 mm Hg, and the remaining 5 eyes required one or two medications to maintain normal IOP. Using IBAGS system, bleb was graded in 142 eyes as follows: H(0) in 3 eyes, H(1) in 45 eyes, H(2) in 90 eyes, and H(3) in 4 eyes, while V(0) was observed in 66 eyes, V(1-3) in 76 eyes. IOP at 18 months in bleb with microcysts was 2.77 mm Hg lower (ß = -2.77, 95%CI = -0.46 to -5.08) than those without microcysts and in bleb with non-vascular was 2.07 mm Hg lower (ß = -2.07, 95%CI = -0.15 to -3.98) than those with vascular at 3 months after surgery. IOP was significantly (ß = -1.20, 95%CI: -0.00 to -2.40) decreased by 1.2 mm Hg with 10 years of age increase (P < 0.05). CONCLUSIONS: Early filtering bleb with microcysts, vascular, and age are identified as important factors to predict long-term IOP effect in patients with PACG after trabeculectomy but not early morphological appearance of filtering bleb.

Laser peripheral iridotomy with and without iridoplasty for primary angle-closure glaucoma: 1-year results of a randomized pilot study.

PURPOSE: To compare the efficacy and safety of laser peripheral iridotomy with or without laser peripheral iridoplasty in the treatment of eyes with synechial primary angle-closure or primary angle-closure glaucoma. DESIGN: Randomized, controlled clinical trial. METHODS: Consecutive patients older than 40 years with synechial primary angle-closure or primary angle closure glaucoma were recruited. Eligible patients were randomized to 1 of 2 treatment options, iridotomy or iridotomy plus iridoplasty, and were followed up for 1 year. Main outcome measures were intraocular pressure (IOP), peripheral anterior synechiae, corneal endothelial cell count, and complications. RESULTS: Seventy-seven eyes (77 patients) were randomized to the iridotomy group, and 81 eyes (81 patients) were randomized to the iridotomy plus iridoplasty group. Sixty-one patients (79.2%) in the iridotomy and 65 patients (80.2%) from the iridotomy plus iridoplasty groups completed 1 year of follow-up. There were no significant differences between the groups in the baseline data. IOP was reduced from 24.66 +/- 13.76 mm Hg to 19.03 +/- 6.21 mm Hg in the iridotomy group (P < .001) and from 27.96 +/- 13.06 mm Hg to 20.45 +/- 7.26 mm Hg in the iridotomy plus iridoplasty group (P < .001). Extent of peripheral anterior synechiae was decreased by 1 more clock-hour after iridoplasty compared with that after iridotomy in the iridotomy plus iridoplasty group (P < .001). There was no significant difference in IOP, medications, need for surgery, or visual function between groups at the 1-year visit. CONCLUSIONS: In eyes with synechial primary angle-closure or primary angle-closure glaucoma, both iridotomy alone or combined with iridoplasty provide a significant and equivalent reduction in IOP. There is also a possible reduction in peripheral anterior synechiae, more so in the iridoplasty group.