AIM:To study the microvascular density of the macular and optic nerve head in healthy and glaucoma subjects using optical coherence tomography angiography.
METHODOLOGY:We performed a cross-sectional ...cohort study on healthy subjects and patients with glaucoma. The AngioVue Enhanced Microvascular Imaging System was used to capture the optic nerve head and macula images during one visit. En face segment images of the macular and optic disc were studied in layers. Microvascular density of the optic nerve head and macula were quantified by the number of pixels measured by a novel in-house developed software. Areas under the receiver operating characteristic curves (AUROC) were used to determine the accuracy of differentiating between glaucoma and healthy subjects.
RESULTS:A total of 24 (32 eyes) glaucoma subjects (57.5±9.5-y old) and 29 (58 eyes) age-matched controls (51.17±13.5-y old) were recruited. Optic disc and macula scans were performed showing a greater mean vessel density (VD) in healthy compared with glaucoma subjects. The control group had higher VD than the glaucoma group at the en face segmented layers of the optic disc (optic nerve head0.209±0.05 vs. 0.110±0.048, P<0.001; vitreoretinal interface0.086±0.045 vs. 0.052±0.034, P=0.001; radial peripapillary capillary0.146±0.040 vs. 0.053±0.036, P<0.001; and choroid0.228±0.074 vs. 0.165±0.062, P<0.001). Similarly, the VD at the macula was also greater in controls than glaucoma patients (superficial retina capillary plexus0.115±0.016 vs. 0.088±0.027, P<0.001; deep retina capillary plexus0.233±0.027 vs. 0.136±0.073, P<0.001; outer retinal capillary plexus0.190±0.057 vs. 0.136±0.105, P=0.036; and choriocapillaris0.225±0.053 vs. 0.153±0.068, P<0.001. The AUROC was highest for optic disc radial peripapillary capillary (0.96), followed by nerve head (0.92) and optic disc choroid (0.76). At the macula, the AUROC was highest for deep retina (0.86), followed by choroid (0.84), superficial retina (0.81), and outer retina (0.72).
CONCLUSIONS:Microvascular density of the optic disc and macula in glaucoma patients was reduced compared with healthy controls. VD of both optic disc and macula had a high diagnostic ability in differentiating healthy and glaucoma eyes.
Primary open angle glaucoma (POAG) is a complex disease and a leading cause of irreversible blindness, and its underlying pathophysiology remains poorly understood. Proteomic characterization of the ...protein composition of aqueous humor (AH) may identify prognostic candidate proteins involved in pathogenesis and progression of the disease. To delineate the possible mechanisms that lead to POAG, this study adopted state-of-art mass spectrometric technique and analyzed AH of POAG and their respective controls. In total, more than 1000 proteins were identified with false discovery rate of less than 1%. Numerous proteins of complement cascade, immunoglobulin, neuronal and amyloidogenic proteins, which were part of processes like acute-phase and inflammatory response, humoral immune and acute inflammatory response, regulation of complement activation and protein processing were identified. Proteins of complement system underwent significant changes, which correlate to pathogenic events characterizing POAG, including altered complement cascade, astrocyte activation, neural degeneration, and apoptosis. Further, protein modification such as deamidation of complement subcomponent was noted, particularly in POAG. Proteomic analysis of AH allows a better understanding of the mechanism involved in the pathogenesis of POAG.
Purpose
The Coronavirus (COVID-19) outbreak is rapidly emerging as a global health threat. With no proven vaccination or treatment, infection control measures are paramount. In this article, we aim ...to describe the impact of COVID-19 on our practice and share our strategies and guidelines to maintain a sustainable ophthalmology practice.
Methods
Tan Tock Seng Hospital (TTSH) Eye Centre is the only ophthalmology department supporting the National Centre for Infectious Diseases (NCID), which is the national screening center and the main center for management of COVID-19 patients in Singapore. Our guidelines during this outbreak are discussed.
Results
Challenges in different care settings in our ophthalmology practice have been identified and analyzed with practical solutions and guidelines implemented in anticipation of these challenges. First, to minimize cross-infection of COVID-19, stringent infection control measures were set up. These include personal protective equipment (PPE) for healthcare workers and routine cleaning of “high-touch” surfaces. Second, for outpatient care, a stringent dual screening and triaging process were carried out to identify high-risk patients, with proper isolation for such patients. Administrative measures to lower patient attendance and reschedule appointments were carried out. Third, inpatient and outpatient care were separated to minimize interactions. Last but not least, logistics and manpower plans were drawn up in anticipation of resource demands and measures to improve the mental well-being of staff were implemented.
Conclusion
We hope our measures during this COVID-19 pandemic can help ophthalmologists globally and serve to guide and maintain safe access in ophthalmology clinics when faced with similar disease outbreaks.
To conduct a preliminary evaluation of the feasibility of visual field fast (VFF), a free iPad-based noise-field perimeter, in detecting glaucomatous scotomas versus the clinical-standard Humphrey ...visual field (HVF) test. VFF confronts subjects with a screen of flickering stimulus, allowing the immediate perception of scotomas.
This was a cross-sectional observational study of 66 glaucoma patients (66 eyes) and 30 healthy controls (30 eyes). All patients had no other visual field disorders. VFF was compared against HVF in terms of whole field and quadrants for the following: (1) correspondence in scotoma detection. (2) Agreement and correlation of the scotoma size (percentage of abnormal visual field area). (3) Test duration. Other domains tested included: (1) correlation of VFF scotoma area with the severity of visual field loss on HVF (mean deviation, MD; visual field index, VFI). (2) Repeatability of VFF. (3) Patient descriptors of scotomas.
Using HVF pattern deviation plot as a reference, VFF detected 52/57 (91.2%) of glaucoma subjects with 1 false-positive (control) (kappa = 0.86). 146/184 (79.3%) of abnormal quadrants (visual field defect present) were localized and 23/157 (14.6%) healthy quadrants were falsely identified as abnormal (kappa = 0.61). VFF underestimated scotoma area as compared to HVF (21.0% versus 44.0%, p < 0.01) but correlated positively (r = 0.268, p = 0.044) with HVF area and negatively with VFI (r = -0.340, p = 0.01) and MD (r = -0.398, p < 0.01). Using HVF total deviation plot as reference, VFF's glaucoma detection rate remained unchanged (kappa = 0.86) with similar quadrant detection (kappa = 0.68). However, a greater underestimation of scotoma area was observed (21.0% versus 85.4%, p < 0.01). VFF's quantitative repeatability was excellent for whole field (intraclass correlation coefficient, ICC: 0.96; p < 0.0001) and quadrants (ICC: 0.82-0.96; all p < 0.001). Qualitatively, 35/37 (94.6%) of subjects reported reduced luminance and flicker in scotomas, with similar morphologies on retests. VFF is faster than HVF SITA-Standard in glaucoma (3.60 ± 1.85 min versus 6.92 ± 1.12 min, p < 0.01) and control (1.12 ± 0.486 min versus 5.16 ± 0.727 min, p < 0.01).
This early model of VFF accurately detected scotomas with high repeatability. However, its accuracy in localizing and quantifying the scotoma can be improved. Considering its portability and cost-effectiveness, VFF demonstrated potential as a general screening tool for moderate-to-severe glaucoma.
Combined phacoemulsification and trabeculectomy is able to achieve greater reduction in intraocular pressure (IOP), higher rates of complete surgical success and fewer postoperative manipulations and ...visits compared with combined phacoemulsification and Xen implantation in glaucomatous eyes.
Our study aims to compare and understand the differences between the efficacy and safety of XEN45 implantation and trabeculectomy in Asian eyes with glaucoma.
This was a retrospective, single-center, comparative study of consecutive patients who underwent combined phacoemulsification and trabeculectomy (Phaco-Trab) from January 2013 to June 2014 and combined phacoemulsification and XEN45 implantation (Phaco-Xen) from May 2017 to September 2018 in a tertiary Ophthalmology center in Singapore. Outcome measures included IOP, number of anti-glaucoma eyedrops, success rate, factors leading to success/failure, number of postoperative interventions and visits required, and surgical complications.
A total of 137 eyes (91 Phaco-Trab, 46 Phaco-Xen) were included. Phaco-Trab group had greater mean IOP reduction at all time points beyond postoperative month (POM) 1 (mean difference 2.9 to 3.8 mm Hg; P<0.05), and greater reduction in mean number of antiglaucoma eyedrops beyond POM3, thought this was not statistically significant. At POM12, complete success was achieved in 83.5% in Phaco-Trab and 52.2% of Phaco-Xen group, respectively (P<0.001). There was no significant factor associated with surgical failure, other than the difference in surgical procedure. Phaco-Trab group required fewer number of postoperative interventions (P=0.009), with only a mean of 0.1 bleb interventions required per patient, versus 1.5 in Phaco-Xen group (P<0.001). Safety profiles in both groups were comparable, with no statistically significant difference in intraoperative/postoperative complications.
Phaco-Trab has significantly higher reduction in both IOP and number of antiglaucoma medications compared with Phaco-Xen group, with greater surgical success and fewer postoperative manipulations and visits. Safety profiles were comparable.
PURPOSE:To determine the prevalence and risk factors for anxiety disorder and depression among glaucoma patients in Singapore, and to assess the relationship between quality of life (QOL) and ...depression/anxiety.
METHODS:In this cross-sectional study, glaucoma patients aged 21 and above with a known diagnosis of primary open-angle glaucoma or primary angle-closure glaucoma were recruited from a tertiary care hospital. Patients with other types of glaucoma, and coexisting ocular or psychiatric disorders were excluded.Ophthalmic examination was carried out on all participants, which included best-corrected visual acuity (BCVA), intraocular pressure (IOP), gonioscopy, standard automated perimetry, and optic disc evaluation. Sociodemographic information and treatment histories were also collected.The Hamilton Depression Rating Scale (HAM-D), Hamilton Anxiety Rating Scale (HAM-A), and Visual Function Questionnaire (VFQ25) were administered to evaluate for depression, anxiety, and impact on QOL, respectively.
RESULTS:A total of 100 patients were included in this study. The mean age was 67.1±12.0 years (range, 24 to 90 y). The frequency of depression and anxiety among our patients was 30% and 64%, respectively. The mean HAM-D score was 4.37±4.17 (range, 0 to 17), whereas the mean HAM-A score was 2.38±2.80 (range, 0 to 13). The mean VFQ25 score was 78.8±16.0 (range, 42.4 to 97.0). The poorest subscale on the VFQ25 was driving, with a mean score of 42.4±42.6 (range, 0.0 to 100.0).We did not find any significant difference between the presence of depression/anxiety between patients with primary open-angle glaucoma (P=0.263) and primary angle-closure glaucoma (P=0.830). Risk factors for depression includedfemale sex (P=0.020), higher logMAR BCVA in the worse eye (P=0.004), higher cup-disc ratio (P=0.016), lower MD in the better and worse eye (P=0.022 and 0.001, respectively), and lower mean VFQ25 score (P<0.001). Risk factors for anxiety includedlower MD in the worse eye (P=0.004) and lower mean VFQ25 score (P=0.004). There was also no significant association between the use of topical β-blockers/carbonic anhydrase inhibitors with depression (P=0.793) or anxiety (P=0.282).
CONCLUSIONS:There is a relatively high prevalence of depression (30%) and anxiety disorders (64%) among glaucoma patients in Singapore. Female glaucoma patients are more likely to suffer from depression. Other risk factors for depression include higher cup-disc ratio, higher logMAR BCVA, lower MD, and a lower mean VFQ25 score. Risk factors for anxiety disorder include lower MD and lower mean VFQ25 score. Ophthalmologists could consider use of the VFQ25 as an assessment for impairments in QOL in a glaucoma patient. If a glaucoma patient is at high risk of depression or anxiety disorder, a multidisciplinary management approach involving ophthalmology and psychiatry may be required.
Purpose
To evaluate efficacy and safety of the iStent inject combined with phacoemulsification in Asian eyes with normal-tension glaucoma (NTG) up to 12 months after surgery.
Study design
...Retrospective case series.
Methods
Retrospective case series of eyes undergoing surgery from April 2017 to August 2019. Outcome measures included intraocular pressure (IOP), number of topical glaucoma medications and adverse outcomes. Data were retrieved from the post-operative day 1 (POD1), week 1 (POW1), month 1 (POM1), month 3 (POM3), month 6 (POM6) and month 12 (POM12) timepoints. Data were analysed at each timepoint for eyes with available clinical data at that visit. Subgroup analysis was performed for a consistent cohort which included only eyes with data at all six follow-up timepoints.
Results
Data from 91 eyes in the collective subject group was analysed. Majority of subjects were male (53, 58.2%) and Chinese (79, 86.8%). Mean age was 73.2 ± 7.2 years. Pre-operatively, mean IOP was 14.3 ± 3.0 mmHg and mean number of medications was 1.5 ± 0.8. Significant IOP reduction was observed at all timepoints except POW1 and POM12. The number of medications was reduced at all timepoints (
p
< 0.001). By POM12, there was reduction of 1.2 ± 1.0 medications (
p
< 0.001). Both the collective and consistent cohorts demonstrated a trend towards decreasing surgical efficacy with time, in IOP reduction and decrease in medications. None of the eyes experienced sight-threatening complications.
Conclusions
Asian eyes with NTG undergoing combined phacoemulsification and iStent inject surgery demonstrated significant and sustained reduction in number of glaucoma medications up to 12 months post-operatively.
Glaucoma is a malady that occurs due to the buildup of fluid pressure in the inner eye. Detection of glaucoma at an early stage is crucial as by 2040, 111.8 million people are expected to be ...afflicted with glaucoma globally. Feature extraction methods prove to be promising in the diagnosis of glaucoma. In this study, we have used optical coherence tomography angiogram (OCTA) images for automated glaucoma detection. Ocular sinister (OS) from the left eye while ocular dexter (OD) were obtained from right eye of subjects. We have used OS macular, OS disc, OD macular and OD disc images. In this work, local phase quantization (LPQ) technique was applied to extract the features. Information fusion and principal component analysis (PCA) are used to combine and reduce the features. Our method achieved the highest accuracy of 94.3% using LPQ coupled with PCA for right eye optic disc images with AdaBoost classifier. The proposed technique can aid clinicians in glaucoma detection at an early stage. The developed model is ready to be tested with more images before deploying for clinical application.
•Automated detection of glaucoma using OCTA images.•OS macular, OS disc, OD macular and OD disc images are considered.•LPQ, Information fusion, PCA, and AdaBoost classifier are used.•Obtained accuracy of 94.3% for OD optic disc images.
Purpose
Primary angle-closure glaucoma (PACG) is associated with increased intraocular pressure, optic nerve damage, and progressive vision loss, but the molecular mechanism that underpins retinal ...ganglion neuropathy in PACG remains poorly understood. To better understand the pathogenesis of human PACG, we performed the first comprehensive proteomic analysis of aqueous humor (AH) samples from PACG patients and matched control donors to study pathogenic alteration in AH composition in disease.
Methods
High-resolution, label-free, liquid chromatography–tandem mass spectrometry-based quantitative proteomic analyses were performed in AH samples collected from PACG patients and a matched control cohort of patients with cataracts.
Results
The AH proteome comprised of 1363 distinct proteins, of which more than 50% were differentially expressed in PACG (773 total; 501 up-regulated, 272 down-regulated). AH from PACG patients was enriched in atypical collagens and fibronectins, suggesting that the composition of the trabecular matrix is significantly altered in disease. Pathway and cluster analyses revealed that AH protein modulation in PACG is closely associated with biological processes including platelet degranulation, cellular import/export mechanisms, and control of protease activity. In addition, critical mediators of oxygen homeostasis and neuronal function in AH were significantly dysregulated in disease, strongly implicating oxidative stress responses in PACG-associated nerve damage.
Conclusions
Altered AH proteome in human PACG indicated oxidative stress in the neuronal damage that preceded vision loss. Identifying key mediators of PACG pathology will yield new prognostic biomarkers and novel targets for future therapeutic interventions.
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