Acute Primary Angle-closure Glaucoma Research Articles

Visually Significant Ocular Decompression Retinopathy Following Laser Peripheral Iridotomy in a Patient with Primary Acute Angle-Closure Glaucoma

Visually Significant Ocular Decompression Retinopathy Following Laser Peripheral Iridotomy in a Patient with Primary Acute Angle-Closure Glaucoma

Optical Coherence Tomography Angiography Assessment of Optic Nerve Head and Macula across the Primary Angle Closure Disease Spectrum.

The microvasculature of the optic disc and macula in eyes with acute primary angle closure and primary angle closure glaucoma was lower across the disease spectrum, but the significant difference was only observed in primary angle closure glaucoma. To assess the microvasculature in the optic nerve head (ONH) and macula across primary angle-closure disease (PACD) spectrum using optical coherence tomography angiography (OCTA). OCTA (AngioVue, Fremont, CA) imaging was performed on 122 PACD subjects. Flow area (FA) and vessel density (VD) in the ONH, radial peripapillary capillary (RPC) network, and superficial and deep capillary plexuses of the macula were calculated and compared across the PACD spectrum using linear regression models with generalized estimating equations adjusted for inter-eye correlation. A total of 234 eyes including 44 primary angle-closure suspects (PACS), 93 primary angle-closure (PAC), 79 primary angle-closure glaucoma (PACG) and 18 PAC with history of previous acute primary angle-closure (APAC) were included in the analysis. Compared to other groups, PACG eyes showed smaller FA in the ONH (1.35±0.02mm2), RPC (0.78±0.03mm2), and the superficial retinal layer (1.08±0.03mm2) (all P<0.05). Lower VD was also observed in the "whole image", "inside disc", and "peripapillary" regions of the ONH and RPC, and the "whole image" and "parafoveal" regions of the retinal layer in the PACG group when compared with other groups (all P<0.05). No significant differences were found for the other groups (all P>0.05). Lower VD in the ONH, RPC, and superficial retinal layer significantly correlated with worse visual field loss in PACG eyes (all P<0.05). Significant reduction in the microvasculature of the optic disc and macula in PACG suggests that glaucoma development may contribute to lower VD in these regions.

Potential Immune-Inflammatory Proteome Biomarkers for Guiding the Treatment of Patients with Primary Acute Angle-Closure Glaucoma Caused by COVID-19.

Primary acute angle-closure glaucoma (PAACG) is a sight-threatening condition that can lead to blindness. With the increasing incidence of COVID-19, a multitude of people are experiencing acute vision loss and severe swelling of the eyes and head. These patients were then diagnosed with acute angle closure, with or without a history of PACG. However, the mechanism by which viral infection causes PACG has not been clarified. This is the first study to explore the specific inflammatory proteomic landscape in SARS-CoV-2-induced PAACG. The expression of 92 inflammation-related proteins in 19 aqueous humor samples from PAACGs or cataract patients was detected using the Olink Target 96 Inflammation Panel based on a highly sensitive and specific proximity extension assay technology. The results showed that 76 proteins were significantly more abundant in the PAACG group than in the cataract group. Notably, the top eight differentially expressed proteins were IL-8, MCP-1, TNFRSF9, DNER, CCL4, Flt3L, CXCL10, and CD40. Generally, immune markers are related to inflammation, macrophage activation, and viral infection, revealing the crucial role of macrophages in the occurrence of PAACGs caused by SARS-CoV-2.

Eye Emergency: A Case Report On Acute Primary Angle Closure

Acute Primary Angle Closure (APAC) or Acute Glaucoma is a condition where intraocular pressure rapidly increases due to the occlusion of the trabecular meshwork by the iris. This case report aims to present the clinical manifestations of APAC and evaluate the initial treatment strategies to immediately reduce intraocular pressure (IOP) and prevent visual loss. A 63-year-old woman presented with a sudden onset of pain in her left eye, accompanied by redness, headache, blurred vision, and nausea. Her visual acuity in the left eye was 1/300, with an IOP of 69.3 mmHg. Slit-lamp examination revealed hyperemic conjunctiva, mixed conjunctival and pericorneal injection, corneal edema, a shallow anterior chamber with Van Herrick grade I, radially dilated iris, a mid-dilated pupil (4 mm in diameter), and a cloudy lens. Gonioscopy confirmed a closed angle and peripheral anterior synechiae (PAS). The right eye had a shallow anterior chamber with normal IOP. Initial treatment included oral glycerin, intravenous analgesic, oral acetazolamide 250 mg, potassium chloride 600 mg, and topical beta-blocker 0.5%, but showed no improvement. Subsequently, a trabeculectomy was performed. The patient also underwent Laser Peripheral Iridotomy (LPI) on the right eye. This case underscores that acute primary angle closure is an ophthalmic emergency, and timely management is crucial to prevent further complications and visual loss. Postoperative follow-up indicated a significant reduction in IOP and stabilization of visual acuity, highlighting the importance of rapid intervention in APAC cases.

Treat the individual and not the angle.

Glaucoma, the silent thief of sight, is one of the most common vision-threatening conditions. Even though POAG (primary open angle glaucoma) is more common, PACG (primary angle closure glaucoma) is the dreaded variant. ISGEO (International Society for Geographical and Epidemiological Ophthalmology) has classified primary angle closure as PACS (primary angle closure suspect), PAC (primary angle closure), and PACG (primary angle closure glaucoma. The inconspicuous nature of PACS makes its diagnosis and treatment very tricky. To determine which cases are best suited for laser peripheral iridotomy. Laser peripheral iridotomy is the gold standard for acute primary angle closure glaucoma treatment. But there is a lot of confusion regarding its use in PACS as a prophylactic measure. We have tried to throw light on laser peripheral iridotomy, a much debatable topic. The video focuses on various trials regarding laser peripheral iridotomy, the indications, side effects, and contraindications. We have also discussed its use as a therapeutic and prophylactic procedure. The video highlights that the approach of laser peripheral iridotomy should be on a case-by-case basis. https://youtu.be/kiEYI9ct2Oo.

The Effect of Persistent High Intraocular Pressure Treated by Phacoemulsification Combined with Goniosynechialysis in Eyes with Acute Primary Angle- closure Glaucoma

AIM: To investigate the availability and safety of phacoemulsification combined with goniosynechialysis for patients with persistent high intraocular pressure in acute primary angle-closure glaucoma. METHODS: Retrospective study. The clinical data of 31 patients (31 eyes) with persistent high intraocular pressure of primary angle-closure glaucoma treated in our center from January 2018 to April 2022 were collected. Each patient underwent phacoemulsification combined with goniosynechialysis after removing the cloudy corneal epithelium and recording the best corrected visual acuity(BCVA), intraocular pressure, and the appearance of the anterior chamber All data were analyzed statistically. RESULTS: After surgical treatment, the best corrected visual acuity was 0.70 (0.30, 0.90) 1 week, 0.30 (0.20, 0.50), 1 month, 0.30 (0.10,0.40), 3 months after surgery, and 0.30 (0.20,0.40) at the last follow-up, respectively, and it was significantly higher than preoperative 1.40 (1.10,2.00) (P &lt; 0.01). The intraocular pressure was 16.20 (12.30,19.40) mmHg, 11.90 (10.80,14.20) mmHg, 13.80 (12.10,16.20) mmHg, 0.30 (0.10,0.40) mmHg and 11.70 (10.40, 12.40) mmHg at 1 day, 1week, 1 month, 3 months, and the last follow-up, and were significantly lower than preoperative 38.60(33.90,42.80)mmHg (P &lt;0.01 ). The central anterior chamber depth and anterior chamber angle width were significantly different between pre-operation and each visit time after the operation (P &lt; 0.01). CONCLUSION: Phacoemulsification combined with goniosynechialysis is a safe and feasible method to treat patients of acute primary angle-closure glaucoma eyes with persistent high intraocular pressure, which can reopen the anterior chamber angle, control intraocular pressure, and improve the visual acuity.

The anti-apoptotic role of Ginkgolide B via mitochondrial permeability transition pore inhibition in retinal ischemia-reperfusion

This research delves into the effectiveness of Ginkgolide B (GB), a compound from Ginkgo biloba, in combating cell death caused by glaucoma, with a focus on mitochondrial impairment and the mitochondrial permeability transition pore (mPTP). Utilizing models of high intraocular pressure and in vitro glaucoma simulations, the study investigates GB's impact on retinal progenitor cells (RPCs) under oxygen-glucose deprivation/reperfusion (OGD/R) and in a rat glaucoma model. The study methodologies included apoptosis assessment, apoptotic marker analysis via Western blot, and mitochondrial structure and function evaluation. The findings reveal that GB notably decreases apoptosis in RPCs exposed to OGD/R in vitro, and reduces ischemia-reperfusion damage in vivo. GB's protective role is attributed to its ability to preserve mitochondrial integrity, maintain membrane potential, regulate calcium levels, and inhibit mPTP opening. These results underscore GB's potential as a therapeutic agent for acute primary angle-closure glaucoma, highlighting its capability to alleviate mitochondrial damage and apoptosis in RPCs and retinal nerve fiber layer cells.

Ocular decompression retinopathy after phacoemulsification in a patient with primary acute angle-closure glaucoma undergoing chemotherapy.

Ocular decompression retinopathy after phacoemulsification in a patient with primary acute angle-closure glaucoma undergoing chemotherapy.

Three-dimensional choroidal vascularity index and choroidal thickness in fellow eyes of acute and chronic primary angle-closure using swept-source optical coherence tomography.

To compare the three-dimensional choroidal vascularity index (CVI) and choroidal thickness between fellow eyes of acute primary angle-closure (F-APAC) and chronic primary angle-closure glaucoma (F-CPACG) and the eyes of normal controls. This study included 37 patients with unilateral APAC, 37 with asymmetric CPACG without prior treatment, and 36 healthy participants. Using swept-source optical coherence tomography (SS-OCT), the macular and peripapillary choroidal thickness and three-dimensional CVI were measured and compared globally and sectorally. Pearson's correlation analysis and multivariate regression models were used to evaluate choroidal thickness or CVI with related factors. The mean subfoveal CVIs were 0.35±0.10, 0.33±0.09, and 0.29±0.04, and the mean subfoveal choroidal thickness were 315.62±52.92, 306.22±59.29, and 262.69±45.55 µm in the F-APAC, F-CPACG, and normal groups, respectively. All macular sectors showed significantly higher CVIs and choroidal thickness in the F-APAC and F-CPACG eyes than in the normal eyes (P<0.05), while there were no significant differences between the F-APAC and F-CPACG eyes. In the peripapillary region, the mean overall CVIs were 0.21±0.08, 0.20±0.08, and 0.19±0.05, and the mean overall choroidal thickness were 180.45±54.18, 174.82±50.67, and 176.18±37.94 µm in the F-APAC, F-CPACG, and normal groups, respectively. There were no significant differences between any of the two groups in all peripapillary sectors. Younger age, shorter axial length, and the F-APAC or F-CPACG diagnosis were significantly associated with higher subfoveal CVI and thicker subfoveal choroidal thickness (P<0.05). The fellow eyes of unilateral APAC or asymmetric CPACG have higher macular CVI and choroidal thickness than those of the normal controls. Neither CVI nor choroidal thickness can distinguish between eyes predisposed to APAC or CPACG. A thicker choroid with a higher vascular volume may play a role in the pathogenesis of primary angle-closure glaucoma.

Bilateral acute angle closure attack in Weill–Marchesani syndrome: A case report

Bilateral acute primary angle closure attack, though possible, is a rare condition. Secondary causes such as psychotropic drugs (topiramate), snake bite, and general anesthesia have been implicated in various case reports. We hereby describe a rare case of bilateral simultaneous acute angle closure attack secondary to microspherophakia and lens subluxation in a young lady with Weill–Marchesani syndrome, which was initially misdiagnosed as acute primary angle closure glaucoma. This case highlights the importance of eliciting proper history and paying attention to general examination findings to rule out secondary causes in a young patient with bilateral acute angle closure glaucoma.

Paracentral Acute Middle Maculopathy Following Acute Primary Angle Closure and Acute Primary Angle Closure Glaucoma.

To report the prevalence, clinical characteristics and risk factors for paracentral acute middle maculopathy (PAMM) following acute primary angle closure (APAC) and acute primary angle closure glaucoma (APACG). This retrospective study consecutively recruited patients diagnosed with APAC or APACG. Based on the spectral domain optical coherence tomography characteristics, PAMM eyes were divided into three stages. Characteristics of different stages such as the time from symptoms to treatment (TST), retinal thickness and BCVA improvement were analyzed. The risk factors of PAMM were evaluated by binary logistic regression models. A total of 781 eyes of 781 APAC or APACG patients were included, and PAMM was found in 22 (2.9%) of them. Stage III eyes had a significantly longer TST than stage I eyes (P = 0.008) while exhibiting significantly thinner retinal thicknesses (P < 0.0001). The BCVA improvement was significantly worse in the eyes treated in stage III than in those treated in stage I (P = 0.008). Older age, longer axial length and without type 2 diabetes were associated with a lower risk of incident PAMM (OR = 0.95, P = 0.028; OR = 0.52, P = 0.019; OR = 3.92, P = 0.022). PAMM can be secondary to APAC or APACG at a rate of 2.9%. Different visual outcomes were observed in patients who received the intervention at different stages of PAMM. Younger patients with a shorter axial length and type 2 diabetes were found to be more susceptible to PAMM.

Association of body mass index and PXDNL gene variants with acute primary angle closure in southern Chinese population

This study aimed to evaluate the association of body mass index (BMI) and the weight-related gene, peroxidasin-like (PXDNL), with acute primary angle closure (APAC) and primary angle-closure glaucoma (PACG) in southern Chinese population. Total 4700 study subjects (1024 APAC, 781 PACG, and 2895 control subjects) with complete ophthalmic examinations were enrolled into this study. The association of BMI with APAC, PACG and ocular biometric parameters was evaluated. Three PXDNL missense variants were genotyped by TaqMan assay, and their association with APAC and PACG was also investigated. Multivariable logistic regression analysis showed that BMI and body weight were significantly associated with both APAC and PACG (P < 0.01). Multiple linear regression analysis demonstrated that each 1 kg/m2 increased in BMI was associated with 0.038 mm increase in axial length, 0.018 mm increase in central anterior chamber depth, 0.002 mm increase in lens position, 0.012 mm increase in corneal diameter and 0.014 mm decrease in lens thickness among the APAC subjects (P < 0.001), but not with PACG. Genetic association analysis identified that PXDNL rs11985241–rs16916207 CT haplotype conferred a higher risk to APAC (OR = 1.25, P = 0.004) than the TG haplotype, but not with PACG. The APAC subjects carrying the rs11985241 C or rs16916207 T alleles showed significantly lower weight than those carrying the corresponding protective alleles. In summary, this study revealed that lower BMI could be associated with higher risk of APAC. PXDNL could be a new associated gene for APAC.

Clinical presentation of acute primary angle-closure glaucoma during the 2019-nCoV epidemic of Omicron variants: a single-center retrospective study

Objective: To investigate the clinical presentation pattern of acute primary angle-closure glaucoma (PACG) during the 2019 novel coronavirus (2019-nCoV) pandemic over the past three years, and its relationship with 2019-nCoV infections of Omicron variants in Guangdong province. Methods: Ecological study.Patients who were newly diagnosed with acute PACG from February 2020 to January 2023 at the Zhongshan Ophthalmic Center of Sun Yat-sen University were included in the study, and their basic information was collected. Patients were divided into the 2020 group (diagnosed between February 1st, 2020 and January 31st 2021), the 2021 group (diagnosed between February 1st, 2021 and January 31st 2022), and the 2022 group (diagnosed between February 1st, 2022 and January 31st 2023). The clinical presentation pattern of newly diagnosed acute PACG was observed and compared between groups. The daily number of newly diagnosed 2019-nCoV infections in Guangdong province was obtained from the Chinese Center for Disease Control and Prevention. The correlation between the daily number of newly diagnosed acute PACG and that of newly diagnosed 2019-nCoV infections during the epidemic period of Omicron variants between December 2022 and January 2023 was assessed. Results: The study included 1 048 patients with newly diagnosed acute PACG, with 235 for the 2020 group, 274 for the 2021 group, and 539 for the 2022 group. Our results showed that the average weekly number of newly diagnosed acute PACG patients in 2022 [8 (5, 11)] was significantly larger than that in 2020 (4.52±1.95, P<0.05) and 2021 (5.27±2.76, P<0.05). The average weekly number increased to 22.11±20.84 between December 2022 and January 2023. The total number of newly diagnosed acute PACG patients during this period was 199, which was 36.9% (199/539) of the total number of the same year and was 6.63 and 6.42 times as many as that in the same period (December and January) of 2020 and 2021. The proportion of patients with bilateral eye involvement during this period in 2022 was significantly higher than that in 2020 and 2021 (P<0.05). Further analysis found that 88.6% (109/123) of cases had a history of 2019-nCoV infection 2 (0, 3) days before the onset of acute PACG symptoms in average. The estimated daily number of acute PACG onset increased rapidly, peaked on December 23th, 2022, and then dropped gradually. This trend was similar to that of the daily number of new 2019-nCoV infections in Guangdong province. Changes of the daily number of new 2019-nCoV infections in Guangdong province had a positive correlation with the estimated daily number of acute PACG onset (r=0.84, P<0.001). Conclusion: A dramatic increase in the clinical presentation of acute PACG was observed at Zhongshan Ophthalmic Center between December 2022 and January 2023, which was the epidemic period of Omicron variants. There is a correlation between the trend of the estimated daily number of acute PACG onset and that of new 2019-nCoV infections of Omicron variants in Guangdong province, but the exact reason remains to be further studied.

Low ambient temperature and temperature drop as novel risk factors of acute glaucoma: a case-crossover study.

The prevalence of glaucoma has seasonal variation in population, but the role of ambient temperature and its variation remains unclear in this seasonal trend. So, we conducted a time-stratified case-crossover study to examine the association of ambient temperature and temperature change between neighboring days (TCN) with the risk of acute glaucoma. Data on meteorological parameters and glaucoma outpatient visit between 2015 and 2021 covered all districts of Shanghai. Conditional logistic regression with distributed lag nonlinear model was applied to estimate the association of temperature or TCN with the risk of acute glaucoma. A total of 7,746 patients diagnosed with acute primary angle-closure glaucoma (APACG) were included in this analysis. We observed a significant increase in therisk of acute glaucoma with cold temperature and temperature drop. Compared with the referent temperature (32℃), moderate low (12°C) and extreme low (4°C) temperature exposures were associated with higher risk of acute glaucoma outpatient visit, with the highest cumulative OR of 1.46 (95% CI: 1.11, 1.91) and 1.50 (95% CI: 1.09, 2.06) over lag 0-2days. Temperature drop (TCN = - 4°C) also increases the risk of acute glaucoma (OR = 1.34, 95% CI: 1.07, 1.67) over lag 0-7days, comparing with no temperature change. Patients of female and above age 65 were more vulnerable to cold exposure and temperature drop. This case-crossover study provided novel and robust individual-level evidence that low ambient temperature and temperature drop significantly increase the acute glaucoma risk. The findings provide protective strategies for glaucoma patient, especially for female and the old, under cold exposure and sudden temperature decline.

FIRST POSNER SCHLOSSMAN SYNDROME POST COVID-19 INFECTION

Introduction: We reported a unique case report of Posner Schlossman Syndrome (PSS) after Covid-19 infection. Case Illustration: Female 54 y.o. came in our hospital with chief complaint of painless blurred vision, red eye, and very high pressure on right eye (RE). She had the same complaint 1½ months before and diagnosed as acute primary angle closure glaucoma (PACG), treated successfully with good outcome. She also had history of covid-19 infection 1 month before the first attack. Initial visual acuity (VA) of RE is 20/70. Anterior segment showed mild inflammation with flare and cell but no KP, while posterior segment cannot be assessed. IOP was 57.0 mmHg. After 1 month of medication (patient rejected to go inward), the patient finally agreed to the trabeculectomy because VA decreased to 20/200. Perimetry and OCT has been done before the operation, showed decreased parameter. One day, 7-days, and 28-days post operated VA were 3/60, 20/50, and 20/40 respectively, while IOP were 9.0 mmHg, 6.7 mmHg, and 15.0 mmHg respectively. Discussion: PSS can be very similar to acute PACG, though with careful history taking and examination we can distinct the disease. History taking for recurrent attack and unilateral is very important. Examination that showed acute open angle marked IOP with sign of uveitis should lead to PSS. Conclusion: In every attack of glaucoma, PSS has resemblance with acute PACG. The foresight of an ophthalmologist in determining the diagnosis is indeed very important.

Acute Primary Angle-Closure Glaucoma: An Overview

Angle-closure glaucoma (ACG) is a condition that leads to optic nerve neurodegeneration caused by increased intraocular pressure (IOP). It’s an ophthalmic emergency that may cause irreversible visual impairment if left untreated. ACG causes can be classified into Primary and Secondary causes. This article will focus on Primary Angle Closure Glaucoma (PACG). In this article, we will briefly outline the pathophysiology, diagnosis, and management of acute PACG.

The Difference of Lens Thickness in Acute and Chronic Primary Angle Closure Glaucoma

Background: Lens thickness is one of the factors that influence the mechanism of acute primary angle closure glaucoma (PACG). The thicker lens usually results in a shallower anterior chamber angle (ACA), and the gradual and progressive increase in lens thickness with age results in exaggerated shallowing of the ACA. Because lens thickness has an important role in acute PACG mechanism, prophylactic treatment like lens extraction might prevent PACG in early stages. This study aimed to describe the difference in lens thickness in acute and chronic PACG.&#x0D; Methods: The research was a cross-sectional study with samples conducted in Dr. M. Djamil General Hospital from September-December 2019. The number of eyes that fulfilled the inclusion criteria were 50 eyes from 50 patients consisting of 25 eyes with acute PACG and 25 eyes with chronic PACG. Subjects were examined with ocular biometry using A-scan biometry to evaluate lens thickness. Data were processed and analyzed using a computer program with a chi-square test.&#x0D; Results: Mean of lens thickness in acute PACG is 5.02 ± 0.45, while in chronic PACG is 4.86 ± 0.40. The difference in lens thickness in acute and chronic PACG were statistically significant (p = 0,037).&#x0D; Conclusion: Lens thickness is thicker in acute PACG than in chronic PACG.

The Agreement of the Nomogram Tool and Ultrasound Biomicroscopy Images in Calculating Ultrasound Cycloplasty Probe Model in Chinese Patients

Purpose: The aim of the study was to compare and explore the agreement between the nomogram tool and ultrasound biomicroscopy (UBM) images method to calculate the ultrasound cycloplasty (UCP) probe model in Chinese glaucoma patients. Methods: Retrospective analysis of Chinese glaucoma patients who visited Zhongshan Ophthalmic Center in Guangzhou from January to December 2019 and were eligible for UCP surgery. Visual acuity, intraocular pressure (IOP), ocular axial length (AL), and horizontal corneal diameter (white to white [WTW]) were measured. UBM images with clear ciliary body imaging and AL and WTW data were sent to trained personnel for probe model measurements. The data calculated by both methods were analyzed using unweighted and weighted κ statistics. The level of agreement refers to Landis and Koch’s guideline for the strength of agreement indicated with weighted κ values. Results: 1,061 eyes of 642 patients were involved, with a mean age of 61.66 ± 11.66 years. Their best-corrected visual acuity converted to logarithm of minimal-angle-of-resolution (logMAR) scores of −0.18–3.00 with a mean value of 0.69 ± 0.77. IOP was 22.0–60.0 mm Hg with a mean of 27.97 ± 5.66 mm Hg. The mean AL and WTW were 22.88 ± 1.33 (19.15–32.14) mm and 11.52 ± 0.49 (10.00–12.90) mm, respectively. The agreement between the two methods was fair (weighted κ = 0.299), matching in 62.86% of eyes (weighted κ = 0.299, κ = 0.264). The agreement in primary open angle glaucoma, acute primary angle-closure glaucoma, chronic primary angle-closure glaucoma, and secondary glaucoma patients was 60.85% (weighted κ = 0.336, κ = 0.301), 65.06% (weighted κ = 0.146, κ = 0.127), 62.26% (weighted κ = 0.204, κ = 0.184), and 57.97% (weighted κ = 0.332, κ = 0.280) of eyes, respectively. Conclusion: The agreement between UBM images and the nomogram tool to calculate the UCP probe model of Chinese patients is at a fair level. The nomogram tool prefers to use larger probes. Improvements to the nomogram tool, such as including data from more ethnic groups and being able to calculate separately for different types of glaucoma, are needed to improve accuracy. The inclusion of parameters or images from more directions of the eye may help measure probe models more accurately for both the nomogram tool and the UBM image measurement.

Anterior Segment Parameter Changes after Cataract Surgery in Open-Angle and Angle-Closure Eyes: A Prospective Study.

Background: To investigate the anterior segment parameters before and after cataract surgery in open-angle eyes and different subtypes of primary angle-closure glaucoma (PACG) eyes and to further explore the potential relationship between the anterior rotation of the ciliary process and crystalline lens. Methods: An observational, prospective study was performed on 66 patients who had cataract surgery including 22 chronic PACG patients, 22 acute PACG patients, and 22 open-angle cataract patients. Anterior segment parameters including the trabecular-ciliary process distance, ciliary process area, trabecular-ciliary angle (TCA), maximum ciliary body thickness (CBTmax), and so on, were measured using ultrasound biomicroscopy preoperatively and 3 months postoperatively. Results: After the surgery, there were significant increases in TCA (p < 0.001) and CBTmax (p < 0.05) in all three groups, while there was no significant change in the trabecular-ciliary process distance (p > 0.05) in all three groups. No significant difference in the changes of ciliary process area, TCA, and CBTmax (p > 0.05) pre- and postoperatively among the three groups were identified. Conclusions: Extractions of crystalline lenses played similar roles in terms of decreasing the anterior rotation of ciliary processes in open-angle eyes and angle-closure eyes. A natural anatomical abnormality may be a more important factor in the anterior rotation of ciliary processes in PACG patients.

Age-Related Changes in Dynamic Iris Behavior Assessed Using a Programmable Closed-Loop Iris Control System.

The purpose of this study was to develop and test a programmable closed-loop system for tracking, modulating, and assessing dynamic iris behavior, including in the mid-dilated position. A programmable closed-loop iris control system was developed by customizing an ANTERION OCT device (Heidelberg Engineering, Heidelberg, Germany). Custom software was developed to store camera and optical coherence tomography (OCT) images, track pupillary diameter (PD), control a light-emitting diode (LED), and modulate ambient lighting to maintain the iris in a dilated, constricted, or mid-dilated position in real-time. Study participants underwent 3 consecutive 65-second scan sessions. Dynamic iris behavior in the form of peak constriction velocity (PCV) and mid-dilated iris activity (MDIA) were calculated and analyzed offline. Among 58 participants, 56 (96.6%) were eligible for analysis based on achieving and maintaining mean PD within ±10% of the calculated mid-dilated PD. Mean participant age was 49.8 ± 18.9 years. Mean PCV was 3.92 ± 0.83 mm/s, and mean MDIA was 0.37 ± 0.15 mm. The mean difference between the calculated and achieved mid-dilated PD was 0.166 ± 0.192 mm. There were significant negative correlations between PCV and age (slope = -0.022, P < 0.001) and MDIA and age (slope = -0.004, P < 0.001). Success rates were lower (69.0%) but relationships between dynamic iris behavior and age were similar based on achieving and maintaining mean PD within ±5% of the calculated mid-dilated PD. A programmable closed-loop iris control system can modulate dynamic iris behavior and maintain the iris in a mid-dilated position. Pupillary constriction velocity and iris activity in the mid-dilated position decrease with age. This system can be applied to study dynamic disease processes involving the iris and establish novel biometric measures that could serve as risk factors for acute and chronic primary angle closure glaucoma (PACG).