Abstract
To investigate the association of peripheral anterior synechiae (PAS) with intraocular pressure (IOP) and anterior-segment parameters in subjects with primary angle-closure glaucoma (PACG). ...A total of 267 subjects with PACG were recruited and underwent gonioscopy and anterior-segment optical coherence tomography (ASOCT). Customized software was used to measure ASOCT parameters, including angle opening distance (AOD750) and trabecular-iris-space-area (TISA750) at 750 µm from the scleral spur, anterior chamber depth, width, area and volume (ACD, ACW, ACA, ACV), iris thickness (IT750), iris area (IAREA), and lens vault (LV). Presenting IOP was defined as the first IOP reading before the initiation of IOP-lowering treatment. The mean age of the 267 subjects was 67.0 ± 8.9 years, 140 (52.4%) were male, and 246 (92.1%) were of Chinese ethnicity. PAS was present in 122 (45.7%) subjects, and was most frequently found in the superior quadrant (79.5%). Subjects with PAS had greater presenting IOP (28.7 ± 12.9 vs 22.4 ± 9.7 mmHg, p < 0.001), narrower AOD750 (p < 0.001), smaller TISA750 (p < 0.001), ACD (p = 0.04), ACA (p = 0.02), ACV (p = 0.01) and larger LV (p = 0.01) compared to PACG eyes without PAS. No significant differences were noted for iris parameters. A multivariate logistic regression analysis showed that higher presenting IOP (β = 0.20, p < 0.001), worse visual field mean deviation (β = − 0.20, p = 0.01) and narrower AOD750 (β = − 0.25, p = 0.03) were the only parameters that significantly correlated with the extent of PAS in clock hours. Almost one-half of the subjects with PACG demonstrated PAS; these eyes were associated with higher presenting IOP, smaller anterior segment dimensions and more severe disease.
COVID-19 has led to massive disruptions in societal, economic and healthcare systems globally. While COVID-19 has sparked a surge and expansion of new digital business models in different industries, ...healthcare has been slower to adapt to digital solutions. The majority of ophthalmology clinical practices are still operating through a traditional model of ‘brick-and-mortar’ facilities and ‘face-to-face’ patient–physician interaction. In the current climate of COVID-19, there is a need to fuel implementation of digital health models for ophthalmology. In this article, we highlight the current limitations in traditional clinical models as we confront COVID-19, review the current lack of digital initiatives in ophthalmology sphere despite the presence of COVID-19, propose new digital models of care for ophthalmology and discuss potential barriers that need to be considered for sustainable transformation to take place.
The growing global burden of visual impairment necessitates better population eye screening for early detection of eye diseases. However, accessibility to testing is often limited and centralized at ...in-hospital settings. Furthermore, many eye screening programs were disrupted by the COVID-19 pandemic, presenting an urgent need for out-of-hospital solutions. This study investigates the performance of a novel remote perimetry application designed in a virtual reality metaverse environment to enable functional testing in community-based and primary care settings. This was a prospective observational study investigating the performance of a novel remote perimetry solution in comparison with the gold standard Humphrey visual field (HVF) perimeter. Subjects received a comprehensive ophthalmologic assessment, HVF perimetry, and remote perimetry testing. The primary outcome measure was the agreement in the classification of overall perimetry result normality by the HVF (Swedish interactive threshold algorithm–fast) and testing with the novel algorithm. Secondary outcome measures included concordance of individual testing points and perimetry topographic maps. We recruited 10 subjects with an average age of 59.6 (range 28-81) years. Of these, 7 (70%) were male and 3 (30%) were female. The agreement in the classification of overall perimetry results was high (9/10, 90%). The pointwise concordance in the automated classification of individual test points was 83.3% (8.2%; range 75%-100%). In addition, there was good perimetry topographic concordance with the HVF in all subjects. Remote perimetry in a metaverse environment had good concordance with gold standard perimetry using the HVF and could potentially avail functional eye screening in out-of-hospital settings.
Studies using machine learning (ML) approaches have reported high diagnostic accuracies for glaucoma detection. However, none assessed model performance across ethnicities. The aim of the study is to ...externally validate ML models for glaucoma detection from optical coherence tomography (OCT) data. We performed a prospective, cross-sectional study, where 514 Asians (257 glaucoma/257 controls) were enrolled to construct ML models for glaucoma detection, which was then tested on 356 Asians (183 glaucoma/173 controls) and 138 Caucasians (57 glaucoma/81 controls). We used the retinal nerve fibre layer (RNFL) thickness values produced by the compensation model, which is a multiple regression model fitted on healthy subjects that corrects the RNFL profile for anatomical factors and the original OCT data (measured) to build two classifiers, respectively. Both the ML models (area under the receiver operating AUC = 0.96 and accuracy = 92%) outperformed the measured data (AUC = 0.93; P < 0.001) for glaucoma detection in the Asian dataset. However, in the Caucasian dataset, the ML model trained with compensated data (AUC = 0.93 and accuracy = 84%) outperformed the ML model trained with original data (AUC = 0.83 and accuracy = 79%; P < 0.001) and measured data (AUC = 0.82; P < 0.001) for glaucoma detection. The performance with the ML model trained on measured data showed poor reproducibility across different datasets, whereas the performance of the compensated data was maintained. Care must be taken when ML models are applied to patient cohorts of different ethnicities.
To investigate the patterns of visual field (VF) defects in primary angle-closure glaucoma (PACG) across different severity levels and to assess hemifield differences within each severity level.
...Cross-sectional study.
Three hundred four patients diagnosed with PACG were recruited from glaucoma clinics at a Singapore hospital.
Point-wise total deviation values were recorded from the static automated perimetry (Swedish interactive threshold algorithm standard program 24-2; Humphrey model 750 Carl Zeiss Meditec, Dublin, CA) printouts. Patients were excluded if they had unreliable VFs (fixation losses >33% and false-positive responses >15%), had undergone only 10-2 VF testing, had VF defects not typical of glaucoma, or had undergone cataract extraction. Mild, moderate, and severe VF loss were defined by a mean deviation of -6.00 dB or more, -6.01 to -12.00 dB, and -12.01 dB or less, respectively. Each hemifield was divided into regions according to glaucoma hemifield test sectors. The average mean deviation (MD) of each region was obtained using total deviation values.
Between- and within-hemifield differences of the regions across the severity levels.
After excluding ineligible cases, 249 patients with PACG were included in the analysis. Mean age of the patients was 65.7±8.6 years, with a 1:1 gender ratio. The number of patients who had mild, moderate, and severe VFs was 72 (28.9%), 78 (31.3%), and 99 (39.8%), respectively. For between-hemifield comparisons, all regions in the superior hemifield had worse MDs compared with their counterparts in the inferior hemifield across the severity spectrum. Likewise, for within-hemifield comparisons, MDs of the regions gradually worsened with increasing distance from the fixation point.
In this group of clinic-based PACG patients, the superior hemifield was found to be affected more severely than the inferior hemifield, and the differences between them increased with worsening disease severity. The damage was consistently more pronounced in the nasal area.
OBJECTIVE:The objective of this article was to study longitudinal changes in bleb morphology (presence of microcysts and bleb height and vascularity) in subjects enrolled in the Singapore ...5-Fluorouracil (5-FU) trabeculectomy study.
STUDY DESIGN:Retrospective subgroup analysis of a randomized controlled trial.
MATERIALS AND METHODS:Following trabeculectomy with either 5-FU or placebo, subjects were reviewed at day 1, weeks 1, 2, and 3, and months 3, 6, 9, 12, 16, 20, 24, 28, 32, and 36 and intraocular pressure (IOP), presence of microcysts and bleb height and vascularity graded and recorded. Statistical analyses were used to investigate baseline factors (demographics, eye drops use, IOP, treatment type, and comorbidities) that might account for long-term bleb changes and assess the influence of bleb morphology on mean, maximum, minimum, and variation in IOP following trabeculectomy.
RESULTS:One hundred fifty-nine (61.2%) subjects completed follow-up and 71 subjects (44.7%) received 5-FU. Proportion of subjects with microcysts increased posttrabeculectomy till weeks 3 and 6 in 5-FU and placebo-treated eyes, respectively, before decreasing. Presence of microcysts at day 1 and week 2 was associated with lower mean (P=0.027 to 0.033), maximum (P=0.040), and minimum IOP (P=0.010). Mean bleb height decreased over 36 months and at months 20 and 36 was associated with maximum (P=0.031) and minimum IOP (P=0.032), respectively. Mean bleb vascularity decreased till month 9 and remained fairly constant after.
CONCLUSIONS:Microcysts seen early posttrabeculectomy is associated with lower IOP. Blebs reduce in height as they remodel and the relationship between bleb vascularity and IOP is complex.
To evaluate visual field (VF) progression and rate of glaucomatous VF loss in patients with primary angle-closure glaucoma (PACG) using pointwise linear regression (PLR) trend analysis.
Clinic-based ...retrospective study.
Primary angle-closure glaucoma patients with 5 or more reliable VF tests and with 5 years or more of follow-up.
Visual field progression was assessed by PROGRESSOR software version 3.7 (Medisoft, Leeds, United Kingdom) and was defined by the presence of at least 2 adjacent testing points located within the same hemifield that showed progression with a change of -1 dB/year or more (P < 0.01) for inner points or -2 dB/year or more (P < 0.01) for edge points. We also performed a logistic regression analysis to determine the variables associated with rapid progression (defined as mean slope of progressing points ≥-1.5 dB/year).
Visual field progression and rate of VF loss.
Of the 1296 patients who were assessed, 398 (30.7%) fulfilled the inclusion criteria of 5 or more VFs and 5 years or more of follow-up. Visual field progression was observed in 63 of 398 eyes (15.8%) according to the PLR criteria. The overall mean rate of VF change for these patients was -0.12±0.51 dB/year over a mean follow-up period of 10.4±3.7 years. There were no significant differences in the age, gender distribution, follow-up duration, or number of VFs between those who showed progression and those who did not (all P > 0.05). The most common sector of VF progression was the superior arcuate area (65%). Rapid progression was found in 36 patients (57%). Multiple logistic regression analysis revealed older age and higher vertical cup-to-disc ratio (VCDR) at presentation as predictors of rapid progression (all P < 0.005) in the progressing group (n = 63).
In patients with PACG being managed in a hospital setting, VF progression was noted in 15.8%, and the overall rate of VF loss was -0.12±0.51 dB/year. The superior arcuate was the most common sector of progression. Older age and higher VCDR at presentation were associated with rapid progression.
PURPOSE OF REVIEWLens extraction for primary angle-closure glaucoma (PACG) is a subject of increased interest recently, with advocates promoting its benefits of anatomical opening of the angle, ...intraocular pressure (IOP) reduction and improved vision. The present review seeks to evaluate recent available evidence to provide clarity on this potential intervention within the armamentarium of approaches for PACG.
RECENT FINDINGSThe emergence of recent case–control studies, cohort studies and randomized controlled trials has provided a stronger evidence base to equip ophthalmic surgeons with the necessary information to utilize lens extraction in the management of PACG, and to consider whether this should be combined with trabeculectomy or goniosynechialysis. Imaging modalities such as anterior segment optical coherence tomography have yielded new insights into the mechanical features of the lens in angle closure, with the lens thickness and lens vault now quantifiable. A trend is emerging regarding the improvement in IOP control, reduced complication rates and reduced need for IOP-lowering medications in patients who undergo lens extraction for PACG. These issues are discussed, along with aspects of preoperative assessment and surgical techniques.
SUMMARYGood outcomes in terms of long-term IOP control have been found following lens extraction for PACG. Lens extraction should be considered in patients with PACG, especially with hyperopia, or a thick and anteriorly vaulted lens.
Cataract surgery is a common procedure, and cystoid macular edema (CME) is a sight-threatening complication. Prostaglandin analogues are the first-line therapy for glaucoma, but their effect on the ...risk for CME after phacoemulsification is unknown. A systematic search of Medline and PubMed was performed to determine the effect of the use of prostaglandin analogues (PGA) on the development of CME after cataract surgery. A total of 412 articles were identified. Thirteen articles met inclusion criteria and were analyzed using Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria. Prostaglandin analogue use was not associated with the development of clinically significant CME after cataract surgery regardless of the timepoint. There is no evidence for stopping PGA use prior to or during the course of cataract surgery to reduce CME, but caution should be exercised in complex eyes, which appear more susceptible to PGA-mediated CME.
Introduction
There has been a growing interest in the role of vascular factors in glaucoma. Studies have looked at the characteristics of macular choriocapillaris in patients with glaucoma but with ...conflicting results. Our study aims to use swept-source optical coherence tomography angiography (SS-OCTA) to evaluate macular choriocapillaris metrics in normal participants and compare them with patients with early primary open-angle glaucoma (POAG) (mean deviation better than −6dB).
Methods
In this prospective, observational, cross-sectional study, 104 normal controls (157 eyes) and 100 patients with POAG (144 eyes) underwent 3 mm × 3mm imaging of the macula using the Plex Elite 9000 (Zeiss Meditec, Dublin, CA, USA). Choriocapillaris OCTA images were extracted from the device’s built-in review software and were subsequently evaluated for the density and size of choriocapillaris flow deficits.
Results
After adjusting for confounding factors, the density of flow deficits was independently higher in those aged 53 years and above (
P
≤ 0.024) whereas the average flow deficit size was significantly larger in those aged 69 years and above (95% CI = 12.39 to 72.91;
P
= 0.006) in both normal and POAG patients. There were no significant differences in the density of flow deficits (
P
= 0.453) and average flow deficit size (
P
= 0.637) between normal and POAG participants.
Conclusion
Our study found that macular choriocapillaris microvasculature on SS-OCTA is unaltered by subjects with POAG. This suggests that OCTA macular choriocapillaris may not be potentially helpful in differentiating early glaucoma from healthy eyes.
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