Contribution of systemic factors on macular vessel density: a sex-specific population-based study.

PURPOSE: To evaluate the influence of systemic factors on macular vessel density in quantitative Optical Coherence Tomography Angiography (OCTA) by sex. STUDY DESIGN: A cross-sectional study. METHODS: A total of 2018 adults were recruited in this study. Participants were excluded (n=964) due to missing data, eye-related problems, or low OCTA scan quality. Macular vessel densities were measured with OCTA using split-spectrum amplitude decorrelation angiography algorithm. Only the data from the right eyes were selected for analysis. Multivariable linear regression analysis was performed to determine the associations between macular vessel density and obesity-related systemic factors in each gender group. RESULTS: The right eyes of 1054 participants (59.6% women) were enrolled. Men had significantly higher obesity parameters and associated risk factors. In multivariable linear regression analysis in men, older age and type 2 diabetes mellitus were independently associated with lower superficial retinal vessel density (ß = -0.37, p = 0.002; ß = -1.22, p = 0.03) and deep retinal vessel density, respectively (ß = -0.66, p < 0.001; ß = -1.76, p = 0.02); positive association was also observed between body mass index (BMI) and superficial retinal vessel density (ß = 0.56, p = 0.02). In women, only higher systolic blood pressure was independently associated with a lower deep retinal vessel density (ß = -0.50, p = 0.003). CONCLUSIONS: This large cross-sectional study shows that older age and type 2 diabetes mellitus are associated with lower superficial and deep retinal capillary vessel density in men. This may help clinicians better understand how systemic factors influence retinal vessel density in different genders and future studies can ascertain more potential sex differences.

Randomized Control Trial of the Impact of Patient Decision Aid Developed for Chinese Primary Open-Angle Glaucoma Patients.

INTRODUCTION: Patient decision aid (PDA) is a tool to prompt shared decision-making. The aim of this study was to evaluate the impact of a PDA on Chinese primary open-angle glaucoma patients. METHODS: All subjects were randomized into control and PDA group. The questionnaires, including 1) glaucoma knowledge; 2) 8-item Morisky medication adherence scale (MMAS-8); 3) 10-item glaucoma medication adherence self-efficacy scale (GMASES-10); and 4) 16-item decision conflict scale (DCS), were evaluated at baseline, 3- and 6-month follow-up. RESULTS: Totally, 156 subjects participated in this study, including 77 in the control group and 79 in the PDA group. Compared to the control group, PDA group showed around 1 point more improvement in disease knowledge at both 3 and 6 months (both p < 0.05), 2.5 (95% CI: [1.0, 4.1]) and 1.9 (95% CI: [0.2, 3.7]) points more improvement in GMASES-10 at 3 and 6 months, respectively, and reduction in DCS by 8.8 (95% CI: [4.6, 12.9]) points more at 3 months and 13.5 (95% CI: [8.9, 18.0]) points more at 6 months. No difference was detected in MMAS-8. CONCLUSION: PDA led to improvement in disease knowledge and self-confidence in medication adherence and reduced decision conflict compared to control group for at least 6 months.

Optic disc and peripapillary vessel density measured with optical coherence tomography angiography and its associations in Chinese adults: a large population-based study.

PURPOSE: To investigate the optic disc and peripapillary vessel density, as well as its ocular and systemic associations, in healthy eyes among adult Chinese population. METHODS: A population-based cross-sectional eye survey was conducted on Chinese adults residing in Hong Kong. 1891 eyes from 1891 participants who completed 4.5×4.5 mm optical coherence tomography angiography scans were recruited. Among the 1891 eyes, 404 were excluded due to low scan quality, optic disc or retinal disorders and non-Chinese ethnicity. The vessel densities (VDs) at nerve fibre layer plexus (NFLP) at both optic disc and peripapillary were collected for analysis. Multiple linear regression analysis was performed to determine the ocular and systemic associations of NFLP VD. RESULTS: The study included 1487 participants (men: 41.2%) with a mean age of 48.8±15.4 years. The mean NFLP VD of the whole en face image, inside disc and peripapillary region was 53.8%, 42.7% and 60.3%, respectively. In the multivariable model, decreased NFLP VDs were significantly associated with older age, male gender, longer axial length (AL) and lower Signal Strength Index. CONCLUSIONS: This large population-based cross-sectional study provided quantitative data of optic disc and peripapillary NFLP VD which may serve as a normative reference for clinical use. Apart from age, gender and AL, the scan signal strength also should be taken into consideration during the assessment of NFLP VD.

An insect-scale robot reveals the effects of different body dynamics regimes during open-loop running in feature-laden terrain.

The transition from the lab to natural environments is an archetypal challenge in robotics. While larger robots can manage complex limb-ground interactions using sensing and control, such strategies are difficult to implement on small platforms where space and power are limited. The Harvard Ambulatory Microrobot (HAMR) is an insect-scale quadruped capable of effective open-loop running on featureless, hard substrates. Inspired by the predominantly feedforward strategy of rapidly-running cockroaches on uneven terrain (Sponberg, 2007), we used HAMR to explore open-loop running on two 3D printed heterogeneous terrains generated using fractional Brownian motion. The 'pocked' terrain had foot-scale features throughout while the 'jagged' terrain features increased in height in the direction of travel. We measured the performance of trot and pronk gaits while varying limb amplitude and stride frequency. The frequencies tested encompassed different dynamics regimes: body resonance (10-25 Hz) and kinematic running (30-40 Hz), with dynamics typical of biological running and walking, respectively, and limb-transmission resonance (45-60 Hz). On the featureless and pocked terrains, low mechanical cost-of-transport (mCoT) kinematic running combinations performed best without systematic differences between trot and pronk; indicating that if terrain features are not too tall, a robot can transition from homo-to heterogeneous environments in open-loop. Pronk bypassed taller features than trot on the jagged terrain, and higher mCoT, lower frequency running was more often effective. While increasing input power to the robot improved performance in general, lower frequency pronking on jagged terrain allowed the robot to bypass taller features compared with the same input power at higher frequencies. This was correlated with the increased variation in center-of-mass orientation occurring at frequencies near body resonance. This study established that appropriate choice of robot dynamics, as mediated by gait, frequency, and limb amplitude, can expand the terrains accessible to microrobots without the addition of sensing or closed-loop control.

Commercially available seizure detection devices: A systematic review.

IMPORTANCE: Epilepsy can be associated with significant morbidity and mortality. Seizure detection devices could be invaluable tools for both people with epilepsy, their caregivers, and clinicians as they could alert caretakers about seizures, reduce the risk of sudden unexpected death in epilepsy, and provide objective and more reliable seizure tracking to guide treatment decisions or monitor outcomes in clinical trials. OBJECTIVE: To synthesize the characteristics of commercial seizure detection tools/devices currently available. METHODS: We performed a systematic search utilizing a diverse set of resources to identify commercially available seizure detection products for consumer use. Performance data was obtained through a systematic review on commercially available products. OBSERVATIONS: We identified 23 products marketed for seizure detection/alerting. Devices utilize a variety of mechanisms to detect seizures, including movement detectors, autonomic change detectors, electroencephalogram (EEG) based detectors, and other mechanisms (audio). The optimal device for a person with epilepsy depends on a variety of factors including the main purpose of the device, their age, seizure type and personal preferences. Only 8 devices have published peer-reviewed performance data and the majority for tonic-clonic seizures. An informed conversation between the clinician and the patient can help guide if a seizure detection device is appropriate. CONCLUSIONS AND RELEVANCE: Seizure detection devices have a potential to reduce morbidity and mortality for certain people with epilepsy. Clinicians should be familiar with the characteristics of commercially available devices to best counsel their patients on whether a seizure detection device may be beneficial and what the optimal devices may be.

Neural correlates of sign language production revealed by electrocorticography.

OBJECTIVE: The combined spatiotemporal dynamics underlying sign language production remain largely unknown. To investigate these dynamics compared to speech production, we used intracranial electrocorticography during a battery of language tasks. METHODS: We report a unique case of direct cortical surface recordings obtained from a neurosurgical patient with intact hearing who is bilingual in English and American Sign Language. We designed a battery of cognitive tasks to capture multiple modalities of language processing and production. RESULTS: We identified 2 spatially distinct cortical networks: ventral for speech and dorsal for sign production. Sign production recruited perirolandic, parietal, and posterior temporal regions, while speech production recruited frontal, perisylvian, and perirolandic regions. Electrical cortical stimulation confirmed this spatial segregation, identifying mouth areas for speech production and limb areas for sign production. The temporal dynamics revealed superior parietal cortex activity immediately before sign production, suggesting its role in planning and producing sign language. CONCLUSIONS: Our findings reveal a distinct network for sign language and detail the temporal propagation supporting sign production.

Prevalence and Causes of Visual Impairment and Blindness among Adult Chinese in Hong Kong - The Hong Kong Eye Study.

PURPOSE: To investigate the prevalence, associations, and causes of visual impairment and blindness in the adult population of Hong Kong. METHODS: This cross-sectional population-based study included 2018 (870, 43% male) randomly selected adults with a mean age 52 ± 16 years (range 18-90 years) in Hong Kong. Each participant underwent comprehensive ophthalmic examinations. Presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) of each eye was recorded. Prevalence of visual impairment and blindness was calculated using both World Health Organization (WHO) and United States (US) definitions, based on BCVA and PVA. RESULTS: Visual acuity measurements were available for 1952 (96.8%) participants. The prevalence of visual impairment, based on BCVA value, using WHO and US definition, was 1.0 ± 0.1% and 2.7 ± 0.4%, respectively. The prevalence of visual impairment, based on PVA value, was 5.1 ± 0.5% and 14.0 ± 0.8%, using WHO and US definition, respectively. Multivariate analysis demonstrated the presence of visual impairment (PVA, WHO definition) increased significantly with older age (odds ratio 1.039, P < .001) and thinner central cornea thickness (odds ratio 0.994, P = .014), but not significantly associated with other socioeconomic, systemic or ocular parameters after adjusting for age and central corneal thickness. Under-correction of refractive error was the most common reason for presenting visual impairment. Causes of impaired BCVA were cataract (37%), age-related macular degeneration (26%), diabetic macular edema (11%), glaucoma (11%), epiretinal membrane (5%), and unknown (11%). CONCLUSION: The prevalence of visual impairment in Hong Kong increased significantly with older age and thinner central corneal thickness. The major causes for impairment were under-correction of refractive error, cataract, and age-related macular degeneration.

Sounds of seizures.

PURPOSE: A phase I feasibility study to determine the accuracy of identifying seizures based on audio recordings. METHODS: We systematically generated 166 audio clips of 30 s duration from 83 patients admitted to an epilepsy monitoring unit between 1/2015 and 12/2016, with one clip during a seizure period and one clip during a non-seizure control period for each patient. Five epileptologists performed a blinded review of the audio clips and rated whether a seizure occurred or not, and indicated the confidence level (low or high) of their rating. The accuracy of individual and consensus ratings were calculated. RESULTS: The overall performance of the consensus rating between the five epileptologists showed a positive predictive value (PPV) of 0.91 and a negative predictive value (NPV) of 0.66. The performance improved when confidence was high (PPV of 0.96, NPV of 0.70). The agreement between the epileptologists was moderate with a kappa of 0.584. Hyperkinetic (PPV 0.92, NPV 0.86) and tonic-clonic (PPV and NPV 1.00) seizures were most accurately identified. Seizures with automatisms only and non-motor seizures could not be accurately identified. Specific seizure-related sounds associated with accurate identification included disordered breathing (PPV and NPV 1.00), rhythmic sounds (PPV 0.93, NPV 0.80), and ictal vocalizations (PPV 1.00, NPV 0.97). CONCLUSION: This phase I feasibility study shows that epileptologists are able to accurately identify certain seizure types from audio recordings when the seizures produce sounds. This provides guidance for the development of audio-based seizure detection devices and demonstrate which seizure types could potentially be detected.

Exophthalmometry values in the Hong Kong Chinese adult population from a population-based study.

This study aims to establish the range of exophthalmometry values (EV) in the adult Hong Kong (HK) Chinese population, its relationship with various anthropometric parameters, and to compare it with the EV in different ethnic groups.About 1485 adult HK Chinese were drawn from a random sample from the community-based FAMILY Cohort. Participants were interviewed, and comprehensive ophthalmological assessments were conducted. EV was measured using the Hertel's exophthalmometer.EV of both eyes from 630 male (42.4%) and 855 female (57.6%) participants, mean age 54 ±â€Š17.2 and 52 ±â€Š16 respectively were analyzed. The mean EV were found to be 15.3 ±â€Š2.8 mm in the right eye, 15.2 ±â€Š2.9 mm in the left eye for men and 14.4 ±â€Š2.7 mm in the right eye, 14.3 ±â€Š2.7 mm in the left eye for women. There were no differences in the EV between right and left eyes (P > .05). Men had significantly higher EV than women (P < .05) and age was found to be negatively correlated to EV (P < .05). Body height (r = 0.20), weight (r = 0.25), waist (r = 0.11), hip circumference (r = 0.15), body mass index (r = 0.17), interpupillary distance (r = 0.54), and axial length (AL) (r = 0.20) were all found to have statistically significant positive correlations with EV (P < .01). Spherical equivalent was found to have statistically significant negative correlation with EV (P < .01).Our study provides normative data on EV in the HK Chinese population. Height, weight, interpupillary distance, waist, hip circumference, and AL had positive correlations with EV. Spherical equivalent had negative correlation with EV. There was no significant difference in EV between the right and left eye. Age and gender had significant effect on EV.

Macular Vessel Density Measured With Optical Coherence Tomography Angiography and Its Associations in a Large Population-Based Study.

Purpose: We investigate macular perfusion and the systemic and ocular associations in a population-based setting. Methods: In this cross-sectional study, 2018 adults residing in Hong Kong underwent detailed ophthalmic examinations after consenting to participate. Macular perfusion was measured with optical coherence tomography angiography (OCTA) using the split-spectrum amplitude decorrelation angiography algorithm. The parafoveal flow index and vessel area density were quantified using automated custom-built software. Results: Of the 2018 participants, the OCTA measurements were available for 1940, and 1631 (84.1%) had good quality scans. The right eyes of these 1631 participants (43.1% men) were included for final analysis. Mean age was 49.8 years (range, 18-92 years). Mean global macular vessel density was 47.3% and 55.1% for the superficial and deep retinal layers, respectively. In multivariate analysis, lower superficial vessel density remained significantly associated with lower signal strength index (SSI; P < 0.001, standardized ß = 0.607) and male sex (P < 0.001, ß = 0.162), and borderline associated with older age (P = 0.09, ß = -0.045) and longer axial length (AL; P = 0.09, ß = -0.037), while lower deep layer vessel density was significantly associated with lower SSI (P < 0.001, standardized ß = 0.667), longer AL (P < 0.001, ß = -0.097), and higher creatinine (P < 0.001, ß = -0.072). Conclusions: This large population-based study provided normative OCTA data of macular vessel density and demonstrated that a lower superficial retinal vessel density was significantly associated with lower SSI and male sex, while a lower deep layer retinal vessel density was significantly associated with lower SSI, longer AL, and higher level of creatinine. These associations must be considered when interpreting clinical quantitative OCTA data.

Physical exercise and glaucoma: a review on the roles of physical exercise on intraocular pressure control, ocular blood flow regulation, neuroprotection and glaucoma-related mental health.

The benefits of physical exercise on health and well-being have been studied in a wide range of systemic and ocular diseases, including glaucoma, a progressive optic neuropathy characterized by accelerated apoptosis of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP) and insufficient ocular perfusion have been postulated to be the two main theories in glaucoma development and progression. The effects of exercise in these two aspects have been demonstrated by numerous researches. A review in 2009 focusing on these two theories concluded that exercise results in transient IOP reduction but an inconsistent elevation in ocular perfusion. However, the majority of the studies had been conducted in healthy subjects. Over the past decade, technological advancement has brought forth new and more detailed evidence regarding the effects of exercise. Moreover, the neuroprotective effect of exercise by upregulation of neurotrophin and enhancement of mitochondrial function has been a focus of interest. Apart from visual impairment, the mental health issues in patients with glaucoma, which include anxiety and depression, should also be addressed. In this review, we mainly focus on publications from the recent years, so as to provide a comprehensive review on the impact of physical exercise on IOP, ocular perfusion, neuroprotection and mental health in patients with glaucoma.

Randomized Crossover Study Showing Nurse-Led Same Day Review Replacing Next Day Review in Uneventful Phacoemulsification to Be Safe and Efficacious.

Purpose. To study whether nurse led same-day review (SDR) after uneventful phacoemulsification can replace next-day review (NDR) in terms of safety and efficacy. Setting. Patients are recruited from an ophthalmology outpatient clinic in Hong Kong. Design. A prospective, randomized crossover study conducted from November 2012 to 2014. Methods. Inclusion criteria include cataract surgery naïve patients undergoing phacoemulsification under local anaesthesia. All patients were seen by our ophthalmic nurse 2 hours after surgery. Before undergoing phacoemulsification of the first eye, patients were randomized to be reviewed on day 1 or 7 after surgery. Surgeons and reviewing doctors were blinded to patient allocation. For the patients' second eye surgery, group allocation will cross over. Primary outcome measures include visual improvement and patient satisfaction questionnaire. Other measures include cataract characteristics, surgical details, and complications. Statistical tests include paired t-test, Wilcoxon signed rank test, and Chi-square test. Results. 164 eyes from 82 patients were available. Visual improvement, satisfaction, and complications were comparable between both groups. Conclusions. A nurse led SDR can replace NDR in uneventful phacoemulsification in terms of safety and efficacy. Patient satisfaction is also comparable in the setting of Asian culture and when transportation is not a major concern.

Development and pilot-testing of patient decision aid for use among Chinese patients with primary open-angle glaucoma.

BACKGROUND: A patient decision aid (PDA) is a tool for shared decision making (SDM), which emphasises patient empowerment. It is useful in chronic diseases and when there are multiple, no best single treatment option. Although SDM is prevalent in Western countries, its use is limited in Chinese societies, where the adoption of a paternalistic approach is strong. Here, we report the development, acceptance and pilot test results of a PDA targeted at Chinese patients with primary open-angle glaucoma (POAG). METHODS: We developed a PDA designed for use in Chinese patients with POAG. Recruited subjects were given our PDA. Baseline evaluation included decision conflict scale (DCS), validated glaucoma adherence questionnaires and glaucoma knowledge questionnaire. Subjects were briefed through the PDA and instructed to read it that day. Three to four weeks later, follow-up questionnaire as described above were conducted with the addition of acceptance questionnaires. RESULTS: Data from 65 subjects were available. The PDA was well received among subjects. DCS improved from 48.9±20.4 at baseline to 34.3±20.3 during follow-up, with P<0.01. Validated medication adherence questionnaires and knowledge showed improvement from baseline, which was statistically significant. CONCLUSIONS: The use of PDA among Chinese subjects with POAG demonstrated positive reception and acceptance. Evaluation of its initial effects shows improvement in DCS, medication adherence and glaucoma knowledge. The implementation of SDM and PDA among Chinese subjects with POAG is encouraged. Future studies with randomised design and later evaluation time points can further reveal the impacts of PDA among Chinese subjects with POAG.

Use of anti-vascular endothelial growth factor in the management of pterygium.

The rising success of anti-vascular endothelial growth factor (VEGF) therapies in ocular disease has stimulated the use of such treatments in the surgical management of pterygium. We reviewed the literature to better understand the safety and efficacy of the adjunctive role of anti-VEGF treatments for pterygium excision. Without surgery, anti-VEGF alone may favourably alter symptoms and vascularity, but does not cause pterygium regression. Some evidence supports the use of anti-VEGF as an adjuvant therapy to surgery, especially when using a higher dose and a more frequent dosing regimen. Overall, anti-VEGF is generally safe and well tolerated in patients with pterygium. Currently, the evidence does not conclusively support the use of anti-VEGF in pterygium surgery. However, further research may guide unanswered questions regarding the interaction between VEGF and other factors responsible for pterygium growth. In addition, the optimal route and dosage of anti-VEGF administration is not yet known.

A circuit motif in the zebrafish hindbrain for a two alternative behavioral choice to turn left or right.

Animals collect sensory information from the world and make adaptive choices about how to respond to it. Here, we reveal a network motif in the brain for one of the most fundamental behavioral choices made by bilaterally symmetric animals: whether to respond to a sensory stimulus by moving to the left or to the right. We define network connectivity in the hindbrain important for the lateralized escape behavior of zebrafish and then test the role of neurons by using laser ablations and behavioral studies. Key inhibitory neurons in the circuit lie in a column of morphologically similar cells that is one of a series of such columns that form a developmental and functional ground plan for building hindbrain networks. Repetition within the columns of the network motif we defined may therefore lie at the foundation of other lateralized behavioral choices.

Consensual ophthalmotonic reaction in Chinese patients following augmented trabeculectomy or ExPRESS shunt implantation.

INTRODUCTION: Consensual ophthalmotonic reaction (COR) was first described in 1924. Studies following monocular application of glaucoma drops and laser trabeculoplasty showed a drop in fellow eye intraocular pressure (IOP). However, studies following monocular surgery showed heterogeneous results. The purpose of this study was to investigate the COR in Chinese patients who have received monocular filtration surgery. METHODS: A noncomparative retrospective study of 65 eyes undergoing filtration surgery in Queen Mary Hospital was conducted. The IOP was obtained at baseline and postoperative days 1, 3, 7 and 14. Patient's age, sex, type of glaucoma and surgery, preoperative medications, postoperative bleb status, and number of interventions were tabulated. The postoperative IOP measurements over both eyes were obtained, and the readings were averaged to decrease the chances of extreme readings being a one-off event and allow for regression to the mean bias. RESULTS: COR was observed in the unoperated fellow eye. The mean preoperative IOP and averaged postoperative IOP were 17.2 ±â€Š5.2 mm Hg and 20.1 ±â€Š8.9 mm Hg, respectively (P < 0.04). All medications were continued in the fellow eye or even stepped up. Twenty-three percent of patients demonstrated fellow eye IOP rise >30% from baseline, while none showed IOP drop >30% from baseline. DISCUSSION: Following monocular penetrating filtration surgery, our Chinese population demonstrated a significant fellow eye IOP increase in the early postoperative period. We should bear in mind the influence of COR and take care to measure the fellow eye IOP following monocular surgery.

A Case Report: Anti-Psychotic Agents Related Ocular Toxicity.

Chlorpromazine is known to cause ocular pigmentary deposits. However, delayed presentation after cessation of chlorpromazine has not been reported. There are also no reports on whether newer generation of anti-psychotic agents contribute to ocular toxicity. We describe a case of ocular toxicity related to anti-psychotic agents. To the best of our knowledge, this is the first reported case of anterior segment pigmentary deposits associated with olanzapine use, 2 years after the cessation of chlorpromazine. We report a case of ocular toxicity in a patient with history of chlorpromazine usage of 100 mg per day for 13 years and subsequently switched to olanzapine 5 mg for 2 years. There were no signs of ocular toxicity while the patient was on chlorpromazine. However, when the patient switched to olanzapine, she developed the ocular side effect as described for chlorpromazine-induced ocular toxicity, with pigmentary depositions on both corneas and the anterior lens surface and decrease in vision. Olanzapine, a newer anti-psychotic agent, may play a role in the ocular pigmentary deposition, either directly causing pigmentary deposition itself or accentuating the effect of chlorpromazine as the 2 drugs act on the same receptors, although further studies are required to support this hypothesis. As patients with psychiatric conditions may not voluntarily complain of visual symptoms, ocular screening could be considered in these patients receiving chronic anti-psychotic treatment, so that any ocular toxicity could be diagnosed in a timely manner.

The progress in optic nerve regeneration, where are we?

Optic nerve regeneration is an important area of research. It can be used to treat patients suffering from optic neuropathy and provides insights into the treatment of numerous neurodegenerative diseases. There are many hurdles impeding optic regeneration in mammals. The mammalian central nervous system is non-permissive to regeneration and intrinsically lacks the capacity for axonal regrowth. Any axonal injury also triggers a vicious cycle of apoptosis. Understanding these hurdles provides us with a rough framework to appreciate the essential steps to bring about optic nerve regeneration: enhancing neuronal survival, axon regeneration, remyelination and establishing functional synapses to the original neuronal targets. In this review article, we will go through current potential treatments for optic nerve regeneration, which includes neurotrophic factor provision, inflammatory stimulation, growth inhibition suppression, intracellular signaling modification and modeling of bridging substrates.

Management of Primary Angle-Closure Glaucoma.

Primary angle-closure glaucoma (PACG) is a progressive optic nerve degeneration and is defined as a glaucomatous optic neuropathy with associated characteristic enlargement of optic disc cupping and visual field loss that is secondary to ocular hypertension caused by closure of the drainage angle. Angle closure is caused by appositional approximation or adhesion between the iris and the trabecular meshwork. The main treatment strategy for PACG lies in the reduction of intraocular pressure, reopening of the closed angle, and possible prevention of further angle closure. There is no universally agreed best surgical treatment for PACG. Trabeculectomy, goniosynechialysis (GSL), glaucoma implant, and cyclodestructive procedures are effective surgical options. Each of them plays an important role in the management of PACG with its own pros and cons. Accumulating evidence is available to show the effectiveness of visually significant and visually nonsignificant cataract extraction in the treatment of PACG. Trabeculectomy and GSL are often combined with cataract extraction, which may offer additional pressure control benefits to patients with PACG. This review article will discuss laser peripheral iridotomy, argon laser peripheral iridoplasty, and surgeries such as GSL, phacoemulsification, and phaco plus glaucoma surgeries that lower intraocular pressure and also alter the anterior segment and/or drainage angle anatomy. Currently, glaucoma implants and cyclodestruction are mainly reserved for PACG patients who have failed previous filtering operations. Their role as initial surgical treatment for PACG will not be discussed.