Treatment Preferences and Factors Influencing the Management of Primary Angle-Closure Suspect in China: A National Survey Study.

INTRODUCTION: This study explored the current views of ophthalmologists in China on the preferred strategy and the primary influencing factors in managing primary angle-closure suspect (PACS). METHODS: An online survey was distributed via WeChat to ophthalmologists working in hospitals at all levels throughout China to investigate the optimal management strategy and factors influencing the strategy for treating PACS from February to March 2023. Management strategies examined included regular observation (RO), laser peripheral iridectomy (LPI), and phacoemulsification with intraocular lens implantation (PEI). The study explored the factors that influenced clinical decision-making processes and collected demographic information from the respondents for analysis. RESULTS: A total of 1009 ophthalmologists responded; 442 responders considered RO as a reasonable option for patients with PACS, while the majority opted for more positive treatments, with 460 choosing LPI and 107 selecting PEI. Further grouping analysis revealed significant differences between tertiary and lower-level hospitals (P < 0.01) and between public and private hospitals (P < 0.05). Significant differences were found among resident, attending, and senior doctors and between northern and southern hospitals. The top three considerations for ophthalmologists who selected RO were ultrasound biomicroscopy (UBM) without pupillary block, absence of a family history of glaucoma, and good compliance with regular follow-up. For LPI, the factors were UBM indicating pupillary block, glaucoma symptoms, and poor compliance with regular follow-up. For PEI the factors were age, family history of glaucoma, and poor compliance with regular follow-up. CONCLUSION: The majority of ophthalmologists prefer aggressive treatments such as LPI or PEI over RO when dealing with patients with PACS. Disparity existed among ophthalmologists based on their level of experience, hospital ownership and level, and geographical location. The survey underscores the complexity and multifactorial nature of PACS management and highlights the need for further research and standardization of treatment protocols to ensure optimal patient outcomes.

Short-term changes detected by corneal topography and optical coherence tomography after prophylactic laser iridotomy in primary angle closure suspect.

PURPOSE: To evaluate early changes in anterior segment parameters by Scheimpflug-Placido disc topography system and changes in retinal layers by optical coherence tomography in primary angle-closure suspects after laser peripheral iridotomy. METHODS: One eye of 26 patients with primary angle closure suspect and of 20 healthy subjects were included in this retrospective cross-sectional study. Anterior chamber depth/volume, iridocorneal angle and central corneal thickness were obtained by Scheimpflug-Placido disc topography system. Retinal thickness, retinal nerve fiber layer thickness and ganglion cell-inner plexiform layer thickness were acquired by optical coherence tomography. All the tests were repeated 1 week and 1 month after laser peripheral iridotomy. RESULTS: The mean ages of the patients and healthy controls were 64.8 ± 10.7 years and 64.5 ± 3.9 years, respectively (p = 0.990). Anterior chamber depth/volume and iridocorneal angle value were lower in the PACS group (p < 0.001, for all). Anterior chamber volume and iridocorneal angle increased significantly after laser peripheral iridotomy (p = 0.004, for both). While foveal thickness decreased significantly after laser peripheral iridotomy (p = 0.027), retinal nerve fiber layer thickness increased in superior and temporal quadrants (p = 0.038 and p = 0.016, respectively). CONCLUSION: Our results suggest that LPI in patients with PACS provides improved retinal thickness and RNFL thickness, as well as anterior chamber parameters.

Rethinking Prophylactic Laser Peripheral Iridotomy in Primary Angle-Closure Suspects: A Review.

PURPOSE: To examine the generalizability, discuss limitations, and critically appraise recommendations on the management of primary angle-closure suspects (PACSs) that emerged as a result of recent randomized clinical trials challenging the widely accepted clinical practice of offering laser peripheral iridotomy (LPI) to PACS patients. To synthetize findings from these and other studies. DESIGN: Narrative review. SUBJECTS: Patients classified as PACS. METHODS: The Zhongshan Angle-Closure Prevention (ZAP)-Trial and the Singapore Asymptomatic Narrow Angle Laser Iridotomy Study (ANA-LIS) along with accompanying publications were reviewed. Epidemiologic studies reporting on the prevalence of primary angle-closure glaucoma and other precursor forms of the disease were also analyzed along with publications reporting on the natural course of the disease or studies reporting on outcomes after prophylactic LPI. MAIN OUTCOME MEASURES: Incidence of progression to more severe forms of angle closure. RESULTS: Patients recruited in recent randomized clinical trials are asymptomatic, do not have cataracts, may be younger, and have, on average, deeper anterior chambers depth compared with patients treated with LPI in clinics. CONCLUSIONS: The ZAP-Trial and ANA-LIS clearly represent the best available data on PACS management, additional parameters however may need to be considered when physicians face patients in clinic. PACS patients encountered at tertiary referral centers may represent more advanced cases with respect to ocular biometric parameters and may be at higher risk for disease progression compared with those recruited through population-based screening. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

[Predictors of the success of laser peripheral iridotomy and lensectomy in the early stages of primary angle closure disease]. / Prediktory uspekha perifericheskoi lazernoi iridotomii i lensektomii pri nachal'nykh stadiyakh zabolevaniya pervichnogo zakrytiya ugla perednei kamery.

The article reviews literature data on the search for predictors of the success of laser peripheral iridotomy (LPI) and lensectomy in the early stages of primary angle closure disease (PACD) and presents a trend analysis of the studies conducted on individuals identified as primary angle closure suspects (PACs) and those with primary angle closure (PAC). The concept of the review was determined by the ambiguous choice of treatment for patients at the stage of PAC onset. Determining the success predictors of LPI or lensectomy plays a key role in optimizing the treatment of PACD. The results of literature analysis are contradictory, which indicates the need for further research taking into account modern methods of visualization of the eye structures such as optical coherence tomography (OCT), Swept Source OCT (SS-OCT), and the use of uniform criteria for evaluating the effectiveness of treatment.

Assessment of Iris Trabecular Contact in Eyes with Gonioscopic Angle-Closure.

PURPOSE: To investigate the extent of iris trabecular contact (ITC) measured by anterior segment OCT (AS-OCT) and its association with primary angle-closure (PAC) and PAC glaucoma (PACG) in eyes with gonioscopic angle-closure and to determine the diagnostic performance of ITC for detection of gonioscopic angle-closure. DESIGN: Multicenter, prospective study. PARTICIPANTS: A total of 119 healthy participants with gonioscopic open-angle and 170 patients with gonioscopic angle-closure (94 with PAC suspect and 76 with PAC/PACG) were included. METHODS: One eye of each subject was randomly selected for AS-OCT imaging. Angle-opening distance (AOD500) and trabecular iris space area (TISA500) were measured every 10° for 360°. Two criteria of ITC500 were examined: (1) AOD500 = 0 mm and (2) TISA500 = 0 mm2. The association between the extent of ITC500 and PAC/PACG in eyes with gonioscopic angle-closure was analyzed with logistic regression analysis. MAIN OUTCOME MEASURES: Sensitivity and specificity of ITC500 for detection of gonioscopic angle-closure; odds ratio (OR) of PAC/PACG. RESULTS: The sensitivity of ITC500 ≥ 10° for detection of gonioscopic angle-closure ranged from 82.4% (AOD500 = 0 mm) to 84.7% (TISA500 = 0 mm2), and the specificity was 85.7% (for both AOD500 = 0 mm and TISA500 = 0 mm2). The extent of ITC500 determined by AS-OCT, not cumulative gonioscopy score (i.e., the sum of the modified Shaffer grades over 4 quadrants), was associated with the odds of PAC/PACG in eyes with gonioscopic angle-closure; the odds of PAC/PACG increased by 5% for every 10° increase in ITC500 (OR, 1.051, 95% confidence interval [CI], 1.022-1.080 for AOD500 = 0 mm; OR, 1.049, 95% CI, 1.022-1.078 for TISA500 = 0 mm2). Axial length and anterior chamber depth were not associated with PAC/PACG in eyes with gonioscopic angle-closure (P ≥ 0.574). CONCLUSIONS: A greater extent of ITC measured by AS-OCT, not angle-closure determined by gonioscopy, was associated with a greater odds of PAC/PACG in eyes with gonioscopic angle-closure.

New understandings of the pathogenesis of primary angle-closure glaucoma / 中华实验眼科杂志

Primary angle-closure glaucoma (PACG) is still one of the common blinding eye diseases in China.Because of the irreversibility of the vision loss it caused, the factors affecting the early development of glaucoma are of great concern.The understanding of static anatomic structure of high-risk anterior segment, such as shallow anterior chamber, short axial length, thick iris and large anterior lens cannot fully explain the transformation process of PACG, so the specific role of dynamic changes in the development of glaucoma should be further considered.This article expounded the differences in iris volume and dynamic process of elasticity between normal people and patients with PACG, the incoordination between lens and intraocular structure during eyeball development, the dynamic block and expansion of ciliary body, vitreous and choroid, and the latest research on the relationship between the abnormal ocular nerve and vascular system adjustment and change with the onset of PACG, in order to provide guidance for understanding the pathogenesis of PACG, accurate clinical diagnosis and formulation of treatment strategies.

[Primary anterior chamber angle closure: progression from suspect to glaucoma. Part 1. Frequency and rate of transition from suspected primary angle closure to true angle closure and primary angle closure glaucoma]. / Pervichnyi zakrytyi ugol perednei kamery: progressirovanie ot podozreniya do glaukomy. Chast' 1. Chastota i skorost' perekhoda podozreniya na pervichnyi zakrytyi ugol v istinno zakrytyi ugol i pervichnuyu zakrytougol'nuyu glaukomu.

OBJECTIVE: To review the literature devoted to the problem of primary anterior chamber angle closure (PAC) and the development of this pathology from glaucoma suspect to primary angle closure glaucoma. The paper includes a trend analysis of the studies concerning primary angle closure suspects (PACS). The concept of this review is conditioned by the conflicting strategies for treating patients with initial PAC without glaucomatous optic neuropathy. Solving the problem of angle closure plays a key role in preventing the development of PAC glaucoma, which is the world's leading cause of irreversible blindness. This part of the review provides information on the frequency and rate of disease progression in PACS. The analyzed literature data is contradictory and indicates the need for further search that would consider a standardized approach to defining the concept of PAC disease, demographic factors and unified examination methods for generalizing and systematizing data in order to draw out unified treatment recommendations.

[Primary anterior chamber angle closure: progression from suspect to glaucoma. Part 2. Predictors of primary angle closure]. / Pervichnyi zakrytyi ugol perednei kamery: progressirovanie ot podozreniya do glaukomy. Chast' 2. Prediktory pervichnogo zakrytogo ugla.

OBJECTIVE: To review the literature devoted to the search of predictors of primary angle closure (PAC) progression as an important link in the pathogenesis of primary angle-closure glaucoma. This part presents a cluster analysis, describes the mechanisms of PAC development, and considers the studies aimed at discovering the risk factors for the progression of primary angle closure suspect into true angle closure. The results of the analyzed literature are ambiguous, indicating the need for further research that would involve strict inclusion criteria, and a standard approach to defining the primary angle closure disease and expanding the diagnostic parameters, in which a key role belongs to anterior segment optical coherence tomography (AS-OCT).

Lowering of intraocular pressure after phacoemulsification in primary open-angle and angle-closure glaucoma: Correlation with lens thickness.

PURPOSE: To assess anterior chamber configuration changes during phacoemulsification in primary angle-closure suspect (PACS/PAC) and primary open-angle glaucoma (POAG). METHODS: Prospective observational comparative study of anterior segment optical coherence tomography (AS-OCT) findings before and after phacoemulsification on three groups of patients (PACS/PAC, POAG, and controls). Data were collected over a period of 9 months. Main outcome measures included mean change in anterior chamber depth (ACD), angle opening distance (AOD), and trabecular iris space area (TISA). RESULTS: 153 patients (51 PACS/PAC, 51 POAG, and 51 controls) were included in the study. Change in all parameters (ACD, AOD at 500 um, and AOD at 750 um) between the groups demonstrated a greater change in PACS/PAC as compared to POAG and controls. AOD at 750 µm in the temporal quadrant, which has been considered to be having the highest correlation or best representation of the angle, increased in all groups after phacoemulsification (463.59 ± 10.99 vs. 656.27 ± 9.73 mm in PACS; 521.29 ± 16.36 vs. 674.37 ± 8.72 mm in POAG; 549.27 ± 12.40 vs. 702.82 ± 13.04 mm in controls, (P < 0.001). After phacoemulsification, intraocular pressure (IOP) decreased by 2.75 ± 1.17 mm Hg in PACS/PAC (P < 0.001), 2.14 ± 1.33 mm Hg in POAG and 1.90 ± 1.25 mm Hg in controls and it was statistically significant in the PACS group compared to control (P < 0.001). CONCLUSION: Phacoemulsification with intraocular lens implantation is associated with increase in the ACD and angle parameters and a corresponding decrease in IOP. Findings were more pronounced in PACS/PAC suggesting early phacoemulsification may be a treatment option in this group.

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.

Retina Vascular Structures near the Optic Disc and in the Macula in Primary Angle-Closure Suspects.

INTRODUCTION: The main aim of this article was to study the retinal peripapillary and macular vascular structures in eyes with primary angle-closure suspects (PACS) using optical coherence tomography angiography (OCTA). METHODS: In this cross-sectional study, control and PACS subjects were recruited from a community screening. Only one eye per subject was used for analysis. All participants underwent a questionnaire survey, physical and ophthalmic examinations, ocular biometry measurements, and OCTA. We compared basic demographics and vessel structure parameters between control and PACS eyes. Univariate and multivariate linear regression analyses were performed to investigate factors associated with vascular parameters in both groups. RESULTS: Data from 254 subjects including 155 PACS and 99 controls were analyzed. In the peripapillary region, PACS eyes showed similar retina nerve fiber layer (RNFL) and vessel densities (VDs) including and excluding large vessels compared to control eyes. Compared to control eyes, all macular OCTA parameters showed significant differences in PACS eyes, including decreased superficial VD (p = 0.006) and deep VD (p = 0.004), larger fovea avascular zone (FAZ) area (p = 0.006), and longer FAZ perimeter (p = 0.004). Gender (p = 0.039), age (p < 0.001), and Garway-Heath superior hemisphere RNFL (p < 0.001) were risk factors influencing optic disc VD excluding large vessels. Axial length was the major factor affecting macula superficial and deep VDs (p = 0.004 and 0.001 respectively), while PACS was an independent factor associated with larger FAZ perimeter (p = 0.046). CONCLUSION: While PACS and control eyes have comparable RNFL and vascular structure around the optic nerve head, macular vascular structures are significantly different.

The Singapore Asymptomatic Narrow Angles Laser Iridotomy Study: Five-Year Results of a Randomized Controlled Trial.

PURPOSE: To examine the efficacy of laser peripheral iridotomy (LPI) in patients who received a diagnosis of primary angle-closure suspect (PACS). DESIGN: Prospective, randomized controlled trial. PARTICIPANTS: This multicenter, randomized controlled trial (ClinicalTrials.gov identifier, NCT00347178) enrolled 480 patients older than 50 years from glaucoma clinics in Singapore with bilateral asymptomatic PACS (defined as having ≥2 quadrants of appositional angle closure on gonioscopy). METHODS: Each participant underwent prophylactic LPI in 1 randomly selected eye, whereas the fellow eye served as a control. Patients were followed up yearly for 5 years. MAIN OUTCOME MEASURES: The primary outcome measure was development of primary angle closure (PAC; defined as presence of peripheral anterior synechiae, intraocular pressure [IOP] of >21 mmHg, or both or acute angle closure [AAC]) or primary angle-closure glaucoma (PACG) over 5 years. RESULTS: Of the 480 randomized participants, most were Chinese (92.7%) and were women (75.8%) with mean age of 62.8 ± 6.9 years. Eyes treated with LPI reached the end point less frequently after 5 years (n = 24 [5.0%]; incidence rate [IR], 11.65 per 1000 eye-years) compared with control eyes (n = 45 [9.4%]; IR, 21.84 per 1000 eye-years; P = 0.001). The adjusted hazard ratio (HR) for progression to PAC was 0.55 (95% confidence interval [CI], 0.37-0.83; P = 0.004) in LPI-treated eyes compared with control eyes. Older participants (per year; HR, 1.06; 95% CI, 1.03-1.10; P < 0.001) and eyes with higher baseline IOP (per millimeter of mercury; HR, 1.35; 95% CI, 1.22-1.50; P < 0.0001) were more likely to reach an end point. The number needed to treat to prevent an end point was 22 (95% CI, 12.8-57.5). CONCLUSIONS: In patients with bilateral asymptomatic PACS, eyes that underwent prophylactic LPI reached significantly fewer end points compared with control eyes over 5 years. However, the overall incidence of PAC or PACG was low.

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.

Changes in Intraocular Pressure and Angle Structure after Dilation in Primary Angle-Closure Suspects with Visually Significant Cataract.

PURPOSE: To evaluate the safety of pupillary dilation in primary angle-closure suspects (PACS) with concurrent visually significant cataract (VSC), to identify risk factors associated with elevated intraocular pressure (IOP), and to describe changes in anterior segment anatomy after pupillary dilation. DESIGN: Prospective study. PARTICIPANTS: Patients with PACS and VSC and no prior laser or intraocular surgery were recruited. Visually significant cataract was defined as best-corrected visual acuity ≤ 20/40 due to cataract. METHODS: Subjects' eyes were dilated with 0.5% tropicamide and 0.5% phenylephrine hydrochloride. A standardized eye examination, biometry, and swept-source OCT (SS-OCT) were performed before dilation. Intraocular pressure and SS-OCT were repeated 1, 4, and 6 hours postdilation (PDH1, PDH4, and PDH6, respectively). All parameters were compared between time points before and after dilation using paired t test. Linear regression models were used to determine the risk factors associated with postdilation IOP changes. MAIN OUTCOME MEASURES: Change in IOP and SS-OCT parameters from baseline. RESULTS: Seventy-eight eyes from 78 patients were included, with 78, 66, and 12 patients completing the study at PDH1, PDH4, and PDH6, respectively. Mean IOP increased from 14.8 ± 2.6 mmHg at baseline to 15.5 ± 3.5 mmHg at PDH1 (P = 0.03) and decreased to 14.9 ± 3.1 mmHg at PDH4 (P = 0.09). Four patients (5.13%) and 3 patients (3.85%) had an increase in IOP ≥ 5 mmHg at PDH1 and PDH4, respectively. Two patients (2.56%) and 1 patient (1.28%) had an increase in IOP ≥ 8 mmHg at PDH1 and PDH4, respectively. None developed acute primary angle-closure during the observation period. Almost all anterior chamber parameters showed a significant increase after dilation at PDH1 and PDH4, except lens vault and iris volume, which decreased at PDH1 and PDH4 from baseline. Increase in anterior chamber depth was negatively associated with the level of IOP elevation after dilation (P < 0.01). CONCLUSIONS: Dilation of patients' eyes with PACS and VSC in this cohort appears to have a low risk for IOP spike. This may be associated with relaxation of the ciliary muscle leading to posterior displacement of the lens-iris diaphragm and deepening of the anterior chamber.

Peripapillary capillary density in acute angle closure crisis and angle closure suspect: A structure, flow and function correlation study.

PURPOSE: to describe peripapillary vascular changes using Optical Coherence Tomography Angiography (OCT-A) in patients with acute angle closure crisis (AACC) and primary-angle closure-suspects (PACS) in comparison to normal controls. METHODS: This cross-sectional/case-control/non-randomized study was conducted at Cairo University Hospitals. It included 21 eyes following AACC, 21 eyes of PACS and 32 eyes of age-matched-controls. Participants underwent visual field (VF) examination, retinal nerve fiber layer (RNFL) assessment using spectral-domain-OCT (SD-OCT), and radial peripapillary capillary density (RPC%) using OCT-A. RESULTS: There was a statistically significant difference in MD and PSD among the three groups (p ⩽ 0.001). There was a significant difference in mean RNFL among the three groups (p ⩽ 0.001), this decrease was still present when comparing the AACC group to controls p = 0.032. There was a significant decrease in the peripapillary RPC% in all groups p ⩽ 0.001. The correlation between structure, function and flow was studied for all groups. Peripapillary RPC% in AACC was positively correlated to MD and peripapillary RNFL (p ⩽ 0.001). In PACS, RPC% was positively correlated to RNFL (p = 0.012). In controls, RPC% was positively correlated to PSD and peripapillary RNFL (p ⩽ 0.001). AUC was 0.8 for the MD, 0.56 for the RPC and 0.38 for the RNFL. CONCLUSIONS: Peripapillary vessel density was lower in AACC eyes than in suspects and control eyes. OCT-A parameters could be a more sensitive marker than OCT parameters after an AACC attack as evident on ROC analysis. PACS remains a clinical diagnosis as we could not find any significant differences in OCT or OCT-A parameters between suspects and normal healthy controls.

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.

Water-drinking Test and Pharmacologic Mydriasis as Provocative Tests in Primary Angle Closure Suspects.

PURPOSE: To compare the water-drinking test (WDT) and pharmacologic mydriasis as provocative tests in patients with primary angle closure suspect (PACS). METHODS: This observational non-randomized comparative study evaluated changes in intraocular pressure (IOP) in 21 patients with PACS who underwent pharmacologic mydriasis and compared it with IOP changes in 26 patients given the WDT. Ocular biometric and anterior chamber parameters were also assessed. Tests were repeated on the same patient two weeks after performing laser peripheral iridotomy (LPI). RESULTS: The mean age ± standard deviation was 60 ± 7 and 57 ± 9 years in the mydriasis and WDT groups, respectively (P = 0.201). Before LPI, both provocative tests were associated with a significant increase in IOP (mydriasis: 15.1 ± 3.1 to 16.6 ± 3.5 mmHg, P = 0.025; WDT: 16.2 ± 2.8 to 18.5 ± 3.3 mmHg, P < 0.001). However, the IOP changes were not statistically different between groups (P = 0.102). After LPI, only the WDT group showed a continued significant IOP elevation after the test (mydriasis: 16.4 ± 3.3 to 16.7 ± 3.5 mmHg, P = 0.569; WDT: 14.9 ± 3.0 to 17.8 ± 4.1 mmHg, P < 0.001). The post-test IOP change was significantly greater in the WDT than in the mydriasis group (3.0 versus 0.3 mmHg, respectively; P = 0.002). Step-wise multiple regression analysis verified the type of provocative test as the only independent factor affecting the post-test IOP change after LPI (regression coefficient: 2.664; P = 0.002). CONCLUSION: Pharmacologic mydriasis and the WDT had similar IOP elevation before LPI, but after LPI, IOP elevation was much greater in the WDT group.

Ten-year incidence of primary angle closure in elderly Chinese: the Liwan Eye Study.

PURPOSE: To determine the 10-year incidence of all forms of primary angle closure (PAC) in phakic eyes and its risk factors in an urban Chinese population aged 50 years and older. METHODS: Survivors of 1405 baseline participants were invited to attend the 10-year follow-up visit in the Liwan Eye Study. Participants with established baseline angle closure, including primary angle closure suspects (PACS), PAC and primary angle closure glaucoma (PACG), or those who underwent bilateral cataract surgery during the 10-year period, as well as those who did not tolerate gonioscopic examinations, were excluded from this analysis. Incident PAC was present when those with open angles at baseline developed angle closure in any form in either eye during the 10-year period. RESULTS: Among 791 participants who returned during the 10-year follow-up visit, 620 (78.4%) provided data on PAC incidence. The 10-year cumulative incidence of any forms of PAC was 20.5% (127/620, 95% CI 17.4% to 24.9%), including 16.9%, 2.4% and 1.1% with incident PACS, PAC and PACG in either eye, respectively. In multiple logistic regression, significant risk factors for incident angle closure were greater baseline lens thickness (OR=1.82 per mm, p=0.003), shallower anterior chamber depth (OR=3.18 per mm decreased, p=0.010) and narrower angle width (OR=1.63 per decreased angle width, p<0.0001). CONCLUSIONS: Approximately one in five people aged 50 years and older developed some form of angle closure over a 10-year period. Small ocular dimensions and hyperopia at baseline were associated with the development of angle closure.

Low iris and anterior chamber volume is associated with deepening after laser peripheral iridotomy in primary angle closure suspects.

PURPOSE: To evaluate the association between baseline ocular variables and the widening of the anterior chamber angle by laser peripheral iridotomy (LPI) in primary angle closure suspects (PACS) using a new Fourier-domain swept-source anterior segment optical coherence tomography (FD-ASOCT). METHOD: Sixty-six PACS eyes of 41 individuals were enrolled in this prospective interventional case series. An FD-ASOCT (Casia SS-1000 OCT; Tomey, Nagoya, Japan) was used to measure biometric baseline variables and at 1 month after the LPI. Paired t test was used to compare the difference between pre-and post-LPI measurements. Multivariate regression analysis was used to test for an association between baseline iris thickness and volume, anterior chamber depth and volume, and lens vault with a widening of the angle after an LPI. Changes in trabecular iris space area and angle opening distance after the LPI were main outcome measures. RESULTS: The mean age of participants was 58.6 ± 8.7 years, 68.2% of whom were female. The angle opening distance, recess area, and trabecular iris surface area at 500 µm increased by 48 to 73% (all P < 0.001). Lens vault and iris volume did not change. A low anterior chamber volume and low iris volume were associated with angle greater deepening by LPI. CONCLUSION: Eyes with a shallow anterior chamber and thinner irises are more likely to experience angle opening from an LPI.