Primary Angle-closure Glaucoma Eyes Research Articles

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.

Intraocular pressure and gonioscopic findings in primary angle-closure disease in India-a big data study.

To describe the gonioscopic profile and intraocular pressure (IOP) in primary angle-closure (PAC) disease in patients presenting to a tertiary eye care network in India. A cross-sectional hospital-based study that included 31 484 new patients presenting between 2011 and 2021. Patients with a clinical diagnosis of PAC/suspect/glaucoma were included. The data was collected from an electronic medical record system. PAC glaucoma (PACG) (47.55%) was the most common diagnosis followed by PAC (39.49%) and PAC suspect (PACS; 12.96%). Female preponderance (54.6%) was noted with higher mean age at presentation among males (P<0.0001). PACS and PAC showed the highest prevalence in 6th decade but PACG was higher at 7th decade. The probability of angle opening was 95.93%, 90.32% and 63.36% in PACS, PAC and PACG eyes respectively post peripheral iridotomy (PI). Plateau iris syndrome (PIS) was noted in 252 eyes and all showed post dilated rise of IOP. A post dilated IOP rise was also noted with 8.86%, 33.95% and 57.19% eyes with PACS, PAC and PACG respectively with IOP rise between 6-8 mm Hg across the disease spectrum. The superior quadrant is the narrowest angle and difficult to open with indentation and post PI. The probability of angle opening is less in PIS especially the complete variety along with post dilated IOP rise. The post dilated IOP rise in angle closure eyes warrants a careful dilatation, especially with PIS.

The Macular Pigment Optical Density (MPOD) Decrease in Chinese Primary Angle Closure Glaucoma Using the One-Wavelength Reflectometry Method

Purpose The objective of this study was to observe the macular pigment optical density (MPOD) and the relationship between MPOD and retinal thickness in Chinese primary angle-closure glaucoma (PACG) patients by the one-wavelength reflectometry method. Methods This study was a prospective comparative observational study, including 39 eyes from 39 PACG patients (15 men and 24 women, mean age 61.89 ± 12.30) and 41 eyes from 41 controls (20 men and 21 women, mean age 63.24 ± 14.02). We measured the MPOD 7-degree area by the one-wavelength reflectometry method and analyzed both the max and mean optical density (OD). The central retinal thickness (CRT) and the total thickness of the macular ganglion cell layer (GCL), and inner plexiform layer (IPL)were measured by spectral-domain-optical coherence tomography (SD-OCT). Statistical methods such as Shapiro–Wilk test, Fisher’s exact test, chi-square test, two independent samples test and Spearman’s correlation coefficient were used to observe the differences in the MPOD between normal subjects and PACG patients and the correlation between the MPOD and retinal thickness. Results The max optical density (Max OD) (PACG group: 0.302 ± 0.067d.u, control group: 0.372 ± 0.059d.u., p < .001) and mean optical density (Mean OD) (PACG group: 0.124 ± 0.035d.u., control group: 0.141 ± 0.028d.u., p < 0.05) were significantly reduced in PACG patients compared with control subjects. Significant decreases in GCL + IPL thickness (PACG group: 74.71 ± 39.56 μm, control group:113.61 ± 8.14 μm, p < 0.001) and CRT (PACG group: 254.49 ± 41.47 μm, control group:329.10 ± 18.57 μm, p < 0.001) were also observed in PACG eyes. There was no statistically significant correlation between the MPOD and GCL + IPL thickness (p = .639, p = .828). Conclusions MPOD was significantly lower in Chinese PACG patients than in the control group, potentially due to thinning of the GCL + IPL thickness. This study provides insights for the pathophysiology, assessment of PACG and potential guidance for lifestyle modifications.

Comparison of intraocular pressure and anterior segment parameters in subjects with asymmetrical primary angle closure disease.

To compare intraocular pressure (IOP) and anterior segment parameters between eyes with unilateral primary angle closure glaucoma (PACG) and their fellow eyes with primary angle closure (PAC) or primary angle closure suspect (PACS). Subjects underwent anterior segment imaging using 360-degree swept-source optical coherence tomography (SS-OCT, CASIA Tomey, Nagoya, Japan) and ocular investigations including gonioscopy and IOP measurement. Each SS-OCT scan (divided into 8 frames, 22.5 degrees apart) was analysed and an average was obtained for the following anterior segment parameters: iridotrabecular contact (ITC), angle opening distance (AOD750), iris thickness and curvature, anterior chamber width, depth and area (ACW, ACD and ACA) and lens vault (LV). Among 132 unilateral PACG subjects (mean age: 62.91 ± 7.2 years; 59.1% male), eyes with PACG had significantly higher presenting IOP (24.81 ± 0.94 vs. 18.43 ± 0.57 mmHg, p < 0.001), smaller gonioscopic Shaffer grade (2.07 ± 0.07 vs. 2.31 ± 0.07, p < 0.001) and a greater extent of peripheral anterior synechiae (PAS, 1.21 ± 0.21 vs. 0.54 ± 0.16 clock hours, p = 0.001). PACG eyes also exhibited increased ITC, ITC area, greater LV and smaller AOD750, ACD and ACA (all p < 0.05). Using the forward stepwise regression model, an increase in 1 mmHg in presenting IOP before laser peripheral iridotomy (LPI)increases the odds of having PACG by 9% (95% confidence interval 5%-14%). PACG eyes have higher presenting IOP, smaller anterior segment parameters, greater extent of PAS, and larger LV compared to their fellow eyes with angle closure. Narrower anterior chamber dimensions and higher presenting IOP before LPI may increase risk of chronic elevated IOP and glaucomatous optic neuropathy after LPI.

Phacoemulsification in angle-closure glaucoma: A 360° evaluation.

To evaluate the effect of phacoemulsification on intraocular pressure (IOP) and anterior chamber angle (ACA) morphology in primary angle-closure glaucoma (PACG). A hospital-based, prospective pre- and post-interventional study was carried out in 40 PAC and PACG eyes post patent PI with visually significant cataracts. All patients underwent phacoemulsification and were evaluated for IOP control, ACA widening, and disease progression for a minimum of 6 months. Failure was defined as an IOP of >21 mmHg necessitating another intervention, including trabeculectomy and/or an increase in the required number of antiglaucoma medications (AGMs) by >1. A highly statistically significant reduction of IOP ( P < 0.0001) was seen with an overall reduction of 42.2% over 6 months and a mean reduction of 8.9 ± 3.59 mmHg, with the requirement of AGMs reducing from 39/40 patients preoperatively to 1/38 postoperatively. Success was seen in 95% of cases, with two patients not achieving target IOP and requiring trabeculectomy. Angle widening was documented in all cases by both gonioscopy and AS-OCT, and none of the patients showed any progression in disc damage and visual field changes. Early cataract surgery in ACG not only helps to control IOP and disease progression by widening angles and improving aqueous outflow but also improves visual acuity and reduces the economic burden of AGMs. It also helps in better evaluation of disease progression by both structural and functional analysis, as was documented by the improved and more reliable visual field indices.

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.

Long-Term Efficacy of Selective Laser Trabeculoplasty in Primary Angle-Closure Disease After Laser Peripheral Iridotomy

ABSTRACT Purpose To evaluate the long-term efficacy of selective laser trabeculoplasty (SLT) in eyes with primary angle-closure (PAC) and primary angle-closure glaucoma (PACG) following a laser peripheral iridotomy (LPI). Method In this prospective cross-sectional study, 45 eyes of 34 patients with PAC/PACG diagnosis, uncontrolled intraocular pressure (IOP), and visible pigmented trabecular-meshwork (TM) at least 180° on gonioscopy following a LPI were recruited. Following a detailed baseline ophthalmic evaluation, all eligible eyes underwent SLT, and the patients were examined on day1, at 1 week, 1-, 3-, and 6-months, and 1-, 2-, 3-, 4-, and 5-year subsequently. The main outcomes measured were IOP, number of IOP-lowering agents, and complications. Results The mean age of the cohort was 57.80 ± 6.44 years, the male–female ratio was 8:26, and 17 eyes were PACG, and 28 were PAC. The baseline IOP was 23.81 ± 1.78 mm Hg, and was significantly declined at all follow-ups (p < .0001). The cumulative probability of overall success was 91% and 84% at 2-, and 5-year, respectively. At 5-year SLT provided drug-freedom in 80% of PAC and 23% of PACG eyes. Six eyes had IOP spike at 1-week and two patients underwent repeat SLT after 1-year. No other complications, such as pain/discomfort, inflammation, an increase in peripheral anterior synechiae and cystoid-macular-edema, were noted. Conclusions SLT appears a safe and cost-effective procedure in PAC/mild- moderate PACG eyes with uncontrolled IOP after laser iridotomy. The long-term effectiveness of SLT as adjuvant treatment was good, but need large sized randomized studies for more validation.

Short‐term intraocular pressure fluctuation in primary angle closure glaucoma

Purpose: To identify the most sensitive period for detecting significant circadian and ultra‐short‐term intraocular pressure (IOP) fluctuation associated with disease progression in primary angle closure glaucoma (PACG).Methods: PACG eyes, which had been followed up for over 2 years under the CUHK PACG Longitudinal (CUPAL) Study, were recruited. Eyes with or without functional or structural glaucomatous progression were classified into ‘progressive’ or ‘stable’ groups based on serial visual field (VF) and retinal nerve fibre layer (RNFL) thickness documentations, respectively. Circadian and ultra‐short‐term IOP fluctuations were recorded by Sensimed Triggerfish® sensors with 288 readings over 30 s, at 5‐min intervals, over a 24‐h period. The circadian IOP fluctuation was represented by smoothed sensor output signals using B‐spline smoothing transform and described by functional data analysis. In each of seven activity‐related 1‐h periods during the examining day, the mean value of the amplitude‐frequency profiles of the signal fluctuations in twelve 30‐s intervals, which represent the ultra‐short‐term IOP fluctuation, was calculated by semi‐variogram/semi‐variance. The signals were compared between ‘progressive’ and ‘stable’ groups by permutation tests on functional t‐statistics.Results: Among the 25 recruited PACG eyes, 16 eyes were classified as RNFL ‘progressive’ group (the mean rate of change in global RNFL thickness: −0.199 ± 0.128 μm/month). Statistically significant differences were found during the time periods from 22:00 to 23:00 and from 07: 00 to 08:00 in gradients that reflected by the first derivative of the IOP fluctuation curve, as well as from 23:00 to 24:00 and 08:00 to 09:00 in curvatures that reflected by the second derivative of the IOP fluctuation curve, between the VF progressive and the VF stable groups (p &lt; 0.05). Gradients differences were also found during the time periods from 24:00 to 01:00 and 02:00 to 03:00 between structural progressive and stable groups (p &lt; 0.05). Higher signal fluctuations, in terms of amplitude‐frequency, were found during the first 1‐h period of sleeping in the RNFL ‘progressive’ group, compared to the RNFL ‘stable’ group (p = 0.028).Conclusions: Between RNFL ‘progressive’ and ‘stable’ PACG eyes, significant differences in circadian IOP fluctuation and ultra‐short‐term IOP fluctuation at the 1‐h period after falling asleep were identified. Large circadian IOP fluctuations may be associated with disease progression in PACG eyes. The first hour of sleeping may be the most sensitive period for detecting significant short‐term IOP fluctuation in PACG eyes.

Comparison of the Choroid in Primary Open-angle and Angle-Closure Glaucoma Using Optical Coherence Tomography.

The current study highlights distinct choroidal alterations in primary open-angle and angle-closure glaucoma, underscoring the potential of choroidal vascularity index as a valuable indicator for understanding glaucoma pathogenesis. To evaluate choroidal structural changes in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) and healthy controls utilizing the choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) by enhanced depth imaging optical coherence tomography (EDI-OCT). This study was cross-sectional. A total of 171 eyes of 171 subjects, comprising 69 eyes with untreated POAG, 58 eyes with untreated PACG and 44 healthy eyes, were enrolled in this study. SFCT, luminal area (LA), stromal area (SA) and total choroidal area (TCA) were measured on EDI-OCT scans. The CVI parameter is calculated as the proportion of LA to TCA. This study included 69 POAG patients with a mean age of 51.4±13.3 years, 58 PACG patients with a mean age of 57.0±7.3 years, and 44 healthy subjects with a mean age of 51.11±10.7 years. The CVI in the POAG and PACG groups was significantly lower than that in the control group (P = 0.001 and P = 0.005, respectively), however not significantly different between the two glaucoma groups (P = 1.000). POAG eyes had significantly lower LA than PACG and controls (P = 0.014 and P = 0.049, respectively), while PACG eyes had significantly greater SA than controls (P = 0.041). The CVI of POAG and PACG eyes was significantly lower than that of normal eyes. A reduced LA was observed mainly in eyes with POAG, and an increased SA was observed mainly in eyes with PACG. The role of the choroid may differ between POAG and PACG eyes.

Structural measurements and vessel density of spectral-domain optic coherence tomography in early, moderate, and severe primary angle-closure glaucoma.

To compare the macular ganglion cell-inner plexiform layer (GCIPL) thickness, retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) parameters, and retinal vessel density (VD) measured by spectral-domain optical coherence tomography (SD-OCT) and analyze the correlations between them in the early, moderate, severe primary angle-closure glaucoma (PACG) and normal eyes. Totally 70 PACG eyes and 20 normal eyes were recruited for this retrospective analysis. PACG eyes were further separated into early, moderate, or severe PACG eyes using the Enhanced Glaucoma Staging System (GSS2). The GCIPL thickness, RNFL thickness, ONH parameters, and retinal VD were measured by SD-OCT, differences among the groups and correlations within the same group were calculated. The inferior and superotemporal sectors of the GCIPL thickness, rim area of ONH, average and inferior sector of the retinal VD were significantly reduced (all P<0.05) in the early PACG eyes compared to the normal and the optic disc area, cup to disc ratio (C/D), and cup volume were significantly higher (all P<0.05); but the RNFL was not significant changes in early and moderate PACG. In severe group, the GCIPL and RNFL thickness were obvious thinning with retinal VD were decreasing as well as C/D and cup volume increasing than other three groups (all P<0.01). In the early PACG subgroup, there were significant positive correlations between retinal VD and GCIPL thickness (except superonasal and inferonasal sectors, r=0.573 to 0.641, all P<0.05), superior sectors of RNFL thickness (r=0.055, P=0.049). More obvious significant positive correlations were existed in moderate PACG eyes between retinal VD and superior sectors of RNFL thickness (r=0.650, P=0.022), and temporal sectors of RNFL thickness (r=0.740, P=0.006). In the severe PACG eyes, neither GCIPL nor RNFL thickness was associated with retinal VD. The ONH damage and retinal VD loss appears earlier than RNFL thickness loss in PACG eyes. As the PACG disease progressed from the early to the moderate stage, the correlations between the retinal VD and RNFL thickness increases.

Deep Learning Classification of Angle Closure based on Anterior Segment OCT

To assess the performance and generalizability of a convolutional neural network (CNN) model for objective and high-throughput identification of primary angle-closure disease (PACD) as well as PACD stage differentiation on anterior segment swept-source OCT (AS-OCT). Cross-sectional. Patients from 3 different eye centers across China and Singapore were recruited for this study. Eight hundred forty-one eyes from the 2 Chinese centers were divided into 170 control eyes, 488 PACS, and 183 PAC+ PACG eyes. An additional 300 eyes were recruited from Singapore National Eye Center as a testing data set, divided into 100 control eyes, 100 PACS, and 100 PAC+ PACG eyes. Each participant underwent standardized ophthalmic examination and was classified by the presiding physician as either control, primary angle-closure suspect (PACS), primary angle closure (PAC), or primary angle-closure glaucoma (PACG). Deep Learning model was used to train 3 different CNN classifiers: classifier 1 aimed to separate control versus PACS versus PAC+ PACG; classifier 2 aimed to separate control versus PACD; and classifier 3 aimed to separate PACS versus PAC+ PACG. All classifiers were evaluated on independent validation sets from the same region, China and further tested using data from a different country, Singapore. Area under receiver operator characteristic curve (AUC), precision, and recall. Classifier 1 achieved an AUC of 0.96 on validation set from the same region, but dropped to an AUC of 0.84 on test set from a different country. Classifier 2 achieved the most generalizable performance with an AUCof 0.96 on validation set and AUC of 0.95 on test set. Classifier 3 showed the poorest performance, with an AUC of 0.83 and 0.64 on test and validation data sets, respectively. Convolutional neural network classifiers can effectively distinguish PACD from controls on AS-OCT with good generalizability across different patient cohorts. However, their performance is moderate when trying to distinguish PACS versus PAC+ PACG. The authors have no proprietary or commercial interest in any materials discussed in this article.

Evaluation of microvascular changes in the retina and choriocapillaris in primary glaucoma and neuromyelitis optica spectrum disorder with optical coherence tomography angiography

BackgroundTo assess quantitatively the microvascular changes in the retina and choroid of healthy eyes, eyes of subjects with primary angle-closure glaucoma (PACG), primary open-angle glaucoma (POAG) and neuromyelitis optica spectrum disorder (NMOSD) using optical coherence tomography angiography (OCTA). MethodsA series of healthy individuals and subjects with PACG, POAG and NMOSD were recruited in this cross-sectional study. OCTA was performed to capture the optic nerve head and macula images and the vessel density (VD) and retinal nerve fiber layer (RNFL) thickness were quantified. The choriocapillary flow density (CFD) was calculated as the percentage of flow area to the whole selected area. ResultsA total of 68 PACG subjects, 25 POAG subjects, 51 NMOSD subjects and 37 healthy controls were enrolled. Significant decreases in peripapillary VD and RNFL thickness were observed in PACG (p < 0.001) and POAG (p < 0.001) eyes and also in NMOSD subjects with an optic neuritis history (p < 0.001) compared with healthy controls. Unaffected eyes in PACG and POAG subjects had lower baseline peripapillary VD than healthy controls (p = 0.002 and p = 0.011, respectively). PACG eyes showed a lower baseline CFD than POAG (p = 0.0027) and the CFD in early and advanced PACG eyes showed a significantly much more decrease than POAG (p = 0.002 and p < 0.001, respectively). ConclusionsThe peripapillary vessel density and RNFL thickness was reduced in glaucomatous and NMOSD eyes compared with healthy controls. PACG eyes showed a lower CFD than POAG and the distinct peripapillary and choriocapillaris microvasculature changes may be correlated to different PACG and POAG pathogenesis.

Relatively anterior lens position in primary angle-closure glaucoma eyes with long axial length.

To evaluate the refractive status and ocular biometric parameters in primary angle-closure glaucoma (PACG) eyes with different axial lengths (ALs). In total, 742 Chinese PACG subjects with complete ophthalmic examinations were enrolled. The refractive status was categorized as myopia (spherical equivalent [SE] ≤-0.5 D), emmetropia (-0.5 D < SE < +0.5 D), and hyperopia (SE ≥+0.5 D), whereas the AL was divided into short (AL <22.5 mm), regular (22.5 ≤ AL <23.5 mm), and long (AL ≥23.5 mm). The refractive status and ocular biometric parameters were compared among different AL groups. The mean AL of the PACG eyes was 22.53 ± 0.84 mm (range: 19.68-25.57 mm). The refractive status was significantly different among different AL groups (P < 0.001). Also, 92.6% of hyperopic PACG eyes showed AL <23.5 mm, and 19.0% of myopic PACG eyes showed AL ≥23.5 mm. The SE showed significant differences among different AL groups only in the hyperopic subjects (P = 0.012). The AL was significantly longer in myopic eyes (P < 0.001). The PACG eyes with longer AL exhibited lower keratometry, longer central anterior chamber depth and corneal diameter, and lens position and relative lens position closer to the anterior (P < 0.001). Axial hyperopia was common in PACG eyes, and axial myopia was not uncommon. Relatively anterior lens position could explain the occurrence of PACG in the eyes with long AL.

Changes of Optic Disc and Macular Vessel Perfusion Density in Primary Angle Closure Glaucoma: A Quantitative Study Using Optical Coherence Tomography Angiograph

Introduction: This study aims to investigate the changes of retinal vascular system in primary angle closure glaucoma (PACG) and acute primary angle closure (APAC) by optical coherence tomography (OCT) angiograph (OCTA) and to evaluate the diagnostic ability of changes of vessel density (VD) in different sectors and layers of optic disc and macular area in APAC and PACG. Methods: In this cross-sectional, observational study, 21 APAC patients (22 eyes) and 21 PACG patients (27 eyes) along with 17 healthy people were enrolled from August 2018 to March 2019. Optic disc region and macular region were imaged using swept-source OCTA system. VD of the macular region was quantified by Image J (1.52a, USA) and Matlab 2018a. The circumpapillary retinal nerve fiber layer (cpRNFL) thickness and ganglion cell complex thickness were obtained by spectral-domain OCT. Results: Compared with the healthy group, the cpRNFL thickness in superior sector was thicker in the APAC group, and this area had the most diffuse microvascular dropout as well. The difference in the macular superficial capillary plexus (SCP) VD between APAC and the control group was not statistically significant. The area under the ROC curves (AUC) of the total optic disc VD in the radial peripapillary capillary (RPC) layer was higher than the AUC of the papillary VD in the optic nerve head (ONH) layer. Compared to the control group, the total optic disc VD, peripapillary VD, and each quadrant of peripapillary VD were decreased in PACG (p < 0.01). In PACG macular region, SCP VD, and deep capillary plexus (DCP) VD, parafovea VD (except temporal sectors) decreased (p < 0.01). The PACG eyes had a greater decrease percentage of VD in total ONH than total macula. The diagnostic value of the VD in the ONH layer and the RPC layer was similar. The diagnostic value of the SCP VD in the macula was greater than the DCP VD in the macula. The AUC was no significant difference between cpRNFL thickness and the total optic disc VD AUC. Conclusion: Elevated intraocular pressure preferentially affects vascular perfusion in the optic disc region more than the macular region in APAC and PACG. In the APAC eyes, there was a perfusion defect in the optic disc region and an increase in RNFL thickness. In this study, the OCTA vascular parameters have similar performance to the OCT structural parameters for glaucoma diagnosis in PACG.

Longitudinal change of peripapillary vessel density and retinal nerve fibre layer thickness in normal tension and primary angle closure glaucoma

PurposeTo compare the rates of peripapillary vessel density (pVD) loss and retinal nerve fibre layer (RNFL) thinning in normal tension glaucoma (NTG) and primary angle closure glaucoma (PACG).MethodsBaseline age and...

The Topographic Relationship Between Choroidal Microvascular Dropout and Glaucomatous Damage in Primary Angle-Closure Glaucoma.

PurposeTo study the topographic relationship between parapapillary choroidal microvasculature dropout (MvD) and parapapillary retinal nerve fiber layer (RNFL) defect in primary angle-closure glaucoma (PACG) eyes.MethodsThis cross-sectional study was carried out in a glaucoma clinic. Patients with PACG and healthy controls were consecutively enrolled. Each subject underwent optical coherence tomography angiography (OCTA) and OCT testing; additionally, visual field (VF) tests were also conducted in the patients with PACG. MvD was determined when choroidal layer images in OCTA showed a complete loss of the microvasculature. The study included 55 patients with PACG and 30 healthy controls.ResultsFifty-five eyes in 55 patients with PACG and 30 eyes in 30 healthy controls were recruited. MvD was found in 26 PACG eyes (47.3%), but no MvD was found in the healthy eyes. Compared with PACG eyes without MvD, eyes with MvD had thinner average RNFL (P < 0.001), worse VF mean deviation (P = 0.006), and lower peripapillary vessel density (P < 0.001). Between MvD and RNFL defects, there was good topographic consistency in angular circumference (Bland–Altman 95% confidence interval [CI], −24.9° to 21.0°) and position (Bland-Altman 95% CI, −18.6° to 20.6°). There was a significant correlation between the MvD angular circumference and the average peripapillary vessel density (r = −0.505; P = 0.014), average RNFL thickness (r = −0.742; P < 0.001), and VF mean deviation (r = −0.572; P = 0.004).ConclusionsIn patients with PACG, the MvD angular circumference and position were highly topographic consistent with those of the peripapillary RNFL defect area. This study suggests that there is a significant correlation between MvD and glaucoma optic nerve injury.Translational RelevanceGiven the vascular etiology for glaucoma, the current research suggests that the MvD angular circumference may serve as a potential supplementary clue of glaucoma disease severity.

Hemisphere opposite to central retinal vascular trunk deviation is earlier affected by glaucomatous damage in primary angle-closure glaucoma.

The purpose of the study was to investigate whether the position of the central retinal vascular trunk (CRVT), as a surrogate for lamina cribrosa (LC) offset, is associated with the dominant hemisphere of visual field defect in primary angle-closure glaucoma (PACG) eyes. Central retinal vascular trunkdeviation was measured from Bruch's membrane opening (BMO) centre, which was delineated by OCT imaging, using the horizontal midline as a reference. The dominant hemisphere developing visual field defect was defined as three connected abnormal points (having a p-value < 5% probability of being normal) appearing in only one hemisphere or each point of the hemisphere having a statistically worse value compared with its mirrored point in the opposite hemisphere on pattern deviation plots. One hundred five (80%) of 132 eyes with PACG had dominant hemisphere of visual field defect initially: 70 eyes (67%) in the superior and 35 eyes (33%) in the inferior hemisphere. The CRVT was located superiorly in the dominant superior visual field defect group (p < 0.001). A logistic regression analysis revealed that superior deviation of the CRVT was the only factor associated with dominant superior visual field defect (p < 0.001). Externally oblique border (EOB) presence was associated with larger BMO (p=0.005) and angular deviation of CRVT (p=0.002). Central retinal vascular trunk deviation was associated with the dominant hemisphere of visual field defect in PACG eyes. This finding implies that the LC position relative to the BMO centre (LC/BMO offset) may incur structural vulnerability in the optic nerve head of PACG eyes.

Comparison of microvascular parameters and diagnostic ability of optical coherence tomography angiography between eyes with primary angle closure glaucoma and primary open angle glaucoma

BackgroundTo investigate and compare the peripapillary and macular microvascular parameters between eyes with primary angle closure glaucoma (PACG) and primary open-angle glaucoma (POAG) using optical coherence tomography angiography (OCTA). MethodsSeventy-nine eyes of 43 patients with primary angle closure glaucoma (PACG), 78 eyes of 43 patients with primary open-angle glaucoma (POAG), 64 eyes of 35 patients with primary angle closure (PAC), and 73 eyes of 40 control subjects underwent imaging with OCTA. Perfusion density (PD) and vessel density (VD) for the macular area, and PD and flux index (FI) for the peripapillary area were calculated automatically. The area under receiver operator characteristic curves (AUC) were constructed to distinguish PACG and POAG eyes from healthy control eyes. ResultsThe peripapillary FI in all quadrants and PD and VD of the macular outer circle in superior and inferior quadrants were significantly lower in PACG and POAG eyes than in control eyes. The peripapillary FI in the inferior quadrant was significantly lower in the POAG group than in the PACG group (0.348 ± 0.06 vs. 0.369 ± 0.06, p = 0.04). The remaining OCTA parameters in the peripapillary and macular area did not show a significant difference between the POAG and PACG groups. Eyes with PAC presented significantly lower PD and VD than healthy control eyes at the superior and inferior quadrant of the macular outer circle, while retinal nerve fiber layer and ganglion cell inner complex thickness were not significantly different from than control eyes. The best diagnostic parameter was peripapillary FI in both PACG (AUC: 0.922) and POAG (AUC: 0.938) eyes. ConclusionsWe found significantly lower peripapillary FI in the inferior quadrant in POAG eyes compared to the PACG eyes, which may indicate the different underlying pathogenesis between POAG and PACG. The PAC eyes had lower macular PD and VD than normal eyes. This suggests that retinal vascular impairment may develop earlier than structural damage in PAC eyes.

Development of Cumulative Order-Preserving Image Transformation Based Variational Autoencoder for Anterior Segment Optical Coherence Tomography Images.

PurposeTo develop a variational autoencoder (VAE) suitable for analysis of the latent structure of anterior segment optical coherence tomography (AS-OCT) images and to investigate possibilities of latent structure analysis of the AS-OCT images.MethodsWe retrospectively collected clinical data and AS-OCT images from 2111 eyes of 1261 participants from the ongoing Asan Glaucoma Progression Study. A specifically modified VAE was used to extract six symmetrical and one asymmetrical latent variable. A total of 1692 eyes of 1007 patients were used for training the model. Conventional measurements and latent variables were compared between 74 primary angle closure (PAC) and 51 primary angle closure glaucoma (PACG) eyes from validation set (419 eyes of 254 patients) that were not used for training.ResultsAmong the symmetrical latent variables, the first three and the last demonstrated easily recognized features, anterior chamber area in η1, curvature of the cornea in η2, the pupil size in η3 and corneal thickness in η6, whereas η4 and η5 were more complex aggregating complex interactions of multiple structures. Compared with PAC eyes, there was no difference in any of the conventional measurements in PACG eyes. However, values of η4 were significantly different between the two groups, being smaller in the PACG group (P = 0.015).ConclusionsVAE is a useful framework for analysis of the latent structure of AS-OCT. Latent structure analysis could be useful in capturing features not readily evident with conventional measures.Translational RelevanceThis study suggested that a deep learning-based latent space model can be applied for the analysis of AS-OCT images to find latent characteristics of the anterior segment of the eye.

Association of Ultra-Short-Term Intraocular Pressure Fluctuation With Disease Progression in Primary Angle Closure Glaucoma: The CUPAL Study.

This study demonstrated significant differences in ultra-short-term IOP fluctuations, measured by a contact lens sensor between progressive and stable PACG eyes, during the first one hour after falling asleep. To identify the most sensitive period for detecting significant ultra-short-term intraocular pressure (IOP) fluctuation associated with disease progression in primary angle closure glaucoma (PACG). PACG eyes, which had been followed up for over 2 years under the CUHK PACG Longitudinal (CUPAL) Study, were recruited. Eyes with or without functional or structural glaucomatous progression were classified into 'progressive' or 'stable' groups on the basis of serial visual field and retinal nerve fiber layer (RNFL) thickness documentations, respectively. Ultra-short-term IOP fluctuations were recorded by Sensimed Triggerfish sensors (Sensimed AG, Lausanne, Switzerland) with 288 readings over 30 seconds, at 5-minute intervals, over a 24-hour period. In each of 7 activity-related 1-hour periods during the examining day, the mean value of the amplitude-frequency profiles of the signal fluctuations in twelve 30-second intervals was calculated by semivariogram/semi-variance. The 'progressive' and 'stable' groups were compared by permutation tests on functional t-statistics. Among the 25 recruited PACG eyes, 16 eyes were classified as RNFL 'progressive' group (the mean rate of change in global RNFL thickness: -0.199 ±0.128μm/mo). Higher signal fluctuations, in terms of amplitude-frequency, were found during the first 1-hour period of sleeping in the RNFL 'progressive' group compared with the RNFL 'stable' group ( P =0.028). Between RNFL 'progressive' and 'stable' PACG eyes, significant differences in ultra-short-term IOP fluctuation at the 1-hour period after falling asleep were identified. The first hour of sleeping may be the most sensitive period for detecting significant ultra-short-term IOP fluctuation in PACG eyes.