Selective Laser Trabeculoplasty for the Treatment of Glaucoma: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the current published literature for high-quality studies on the use of selective laser trabeculoplasty (SLT) for the treatment of glaucoma. This is an update of the Ophthalmic Technology Assessment titled, "Laser Trabeculoplasty for Open-Angle Glaucoma," published in November 2011. METHODS: Literature searches in the PubMed database in March 2020, September 2021, August 2022, and March 2023 yielded 110 articles. The abstracts of these articles were examined to include those written since November 2011 and to exclude reviews and non-English articles. The panel reviewed 47 articles in full text, and 30 were found to fit the inclusion criteria. The panel methodologist assigned a level I rating to 19 studies and a level II rating to 11 studies. RESULTS: Data in the level I studies support the long-term effectiveness of SLT as primary treatment or as a supplemental therapy to glaucoma medications for patients with open-angle glaucoma. Several level I studies also found that SLT and argon laser trabeculoplasty (ALT) are equivalent in terms of safety and long-term efficacy. Level I evidence indicates that perioperative corticosteroid and nonsteroidal anti-inflammatory drug eye drops do not hinder the intraocular pressure (IOP)-lowering effect of SLT treatment. The impact of these eye drops on lowering IOP differed in various studies. No level I or II studies exist that determine the ideal power settings for SLT. CONCLUSIONS: Based on level I evidence, SLT is an effective long-term option for the treatment of open-angle glaucoma and is equivalent to ALT. It can be used as either a primary intervention, a replacement for medication, or an additional therapy with glaucoma medications. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Assessment of the iridocorneal angle pigmentation and structures after the implantation of EVO+ Visian Implantable Collamer Lens.

PURPOSE: To evaluate the effect of EVO+ Visian Implantable Collamer Lens (ICL) implantation on the iridocorneal angle pigmentation and structures. METHODS: Myopic refractive surgery candidates who underwent posterior chamber EVO+ ICL implantation were evaluated preoperatively and 3 and 6 months postoperatively. High-resolution images of the iridocorneal angle (nasal, superior, temporal and inferior quadrants) were acquired during gonioscopy. A masked observer, blinded to study visits and patients' information, evaluated the angle width, apparent iris root insertion, iris configuration, and trabecular meshwork pigmentation according to the Spaeth scale in two different occasions. The intra-rater reliability was estimated using the weighted Gwet's Agreement Coefficient (AC2). Differences between visits were analyzed using the Cochran Q test or the Friedman test. RESULTS: Twenty-one patients (13 females and 8 males) aging 31.3 ± 6.3 years old were recruited. The intra-rater reliability of gonioscopy assessment was excellent for every parameter assessed (AC2 ≥ 0.97). No significant differences were found among the study visits for any quadrant in the angle width (p ≥ 0.74), apparent iris root insertion (p ≥ 0.22), iris configuration (p ≥ 0.21) and trabecular meshwork pigmentation (p ≥ 0.24). Mean pigmentation of trabecular meshwork for the four quadrants did not vary either among visits (p = 0.25). CONCLUSIONS: The EVO+ ICL implantation after uneventful procedures appears not to clinically affect the iridocorneal angle pigmentation and/or structures during a short-medium follow-up using gonioscopy assessment. The intra-rater reliability of glaucoma specialists assessing iridocorneal angle structures using gonioscopy images is very high.

Assessment of Iridotrabecular Contact and Its Association With Intraocular Pressure After Phacoemulsification in Primary Angle Closure.

PURPOSE: To investigate the association between the quantitative assessment of iridotrabecular contact (ITC), measured by swept-source anterior segment optical coherence tomography (SS AS-OCT), and intraocular pressure (IOP) control after phacoemulsification in patients with primary angle closure disease (PACD). DESIGN: Retrospective, clinical cohort study. METHODS: Preoperative and postoperative anterior chamber angle parameters were measured using SS AS-OCT. IOP was measured preoperatively and until 6 months postoperatively. Percent IOP reduction and fluctuation after surgery were calculated, and their relationships with SS AS-OCT parameters were assessed by correlation analyses and locally weighted scatterplot smoothing (LOWESS) regression with change-point analysis. RESULTS: A total of 51 eyes of 51 PACD patients were included. Preoperative ITC index and area (r = 0.626, r = 0.551), as well as changes in ITC index and area (r = 0.632, r = 0.543) after surgery, were significantly correlated with postoperative IOP reduction, after adjusting for age and gender (all P <.001). Higher postoperative ITC index (r = 0.405, P = .005) and ITC area (r = 0.460, P = 0.001) were associated with greater postoperative IOP fluctuations. Change points on LOWESS curves were observed for preoperative ITC index (33.0%) and change in ITC index (27.0%) and percent IOP reductions were significantly correlated with them above (ß = 0.386, ß = 0.664, all P < .001) but not below the change points. CONCLUSIONS: Quantitative assessment of circumferential ITC can predict postoperative IOP control after phacoemulsification, and thus it may be used as a reference for determining lens extraction in PACD eyes.

Cost-Effectiveness Analysis of Minimally Invasive Trabecular Meshwork Stents with Phacoemulsification.

PURPOSE: To investigate the costs and effects of implanting trabecular meshwork bypass stents during cataract surgery from a societal perspective in the United States. DESIGN: Cost-utility analysis using Markov models and efficacy/safety data from published pivotal or randomized control trials (RCTs) of devices investigated. PARTICIPANTS: Patients aged 65 years and older with mild to moderate primary open-angle glaucoma with or without visually significant cataract. METHODS: With the use of Markov models, glaucoma progression through 4 glaucoma states (mild, moderate, advanced, severe/blind) and death were simulated over 35 years. The cohort with cataract entered the model and received cataract surgery with or without device implantation. We included a medication management only reference group to calculate total costs and outcomes for those without cataract. Intraocular pressure (IOP) reductions from RCTs were converted to glaucoma state transition probabilities using visual field (VF) mean deviation (MD) decline rates from the Early Manifest Glaucoma Trial. Progressive thinning of the retinal nerve fiber layer (RNFL) on OCT imaging related to IOP control warranted further intervention, including adding medication, selective laser trabeculoplasty (SLT), or incisional glaucoma surgery. We estimated whole costs at Medicare rates and obtained utility values for glaucoma states from previous studies. Incremental costs per quality-adjusted life-year (QALY) gained were evaluated at a QALY threshold of $50 000. One-way deterministic sensitivity analysis, scenario analyses, and probabilistic sensitivity analyses addressed parameter uncertainty and demonstrated model robustness. MAIN OUTCOME MEASURES: Total costs, QALY, and incremental cost-effectiveness ratio (ICER). RESULTS: Over 35 years in the base case, the Hydrus (Ivantis, Inc.) implanted with cataract surgery arm cost $48 026.13 and gained 12.26 QALYs. The iStent inject (Glaukos Corp.) implanted with cataract surgery arm cost $49 599.86 and gained 12.21 QALYs. Cataract surgery alone cost $54 409.25 and gained 12.04 QALYs. Initial nonsurgical management cost $57 931.22 and gained 11.74 QALY. The device arms dominated or were cost-effective compared with cataract surgery alone within 5 years and throughout sensitivity analyses. The iStent inject arm was cost-effective in 94.19% of iterations in probabilistic sensitivity analyses, whereas the Hydrus arm was cost-effective in 94.69% of iterations. CONCLUSIONS: Implanting the Hydrus Microstent or iStent inject during cataract surgery is cost-effective at a conservative QALY threshold.

Assessment of differential intraocular pressure response to dexamethasone treatment in perfusion cultured Indian cadaveric eyes.

The purpose of the present study was to assess the differential intraocular pressure response (IOP) to dexamethasone (DEX) treatment at two dose levels (100 or 500 nM) in perfusion cultured Indian cadaveric eyes to investigate glucocorticoid (GC) responsiveness. In a human organ-cultured anterior segment (HOCAS) set-up, the eye pressure was monitored for every 24 h post DEX infusion (100 or 500 nM) or 0.1% ethanol treatment for 7 days after baseline stabilization. The expression of DEX-inducible proteins such as myocilin and fibronectin in HOCAS-TM tissues was assessed by immunostaining. Elevated IOP was observed in 6/16 eyes [Mean ± SEM (mΔIOP): 15.50 ± 1.96 mmHg; 37.5% responders] and 3/15 eyes (Mean ± SEM mΔIOP: 10 ± 0.84 mmHg; 20% responders) in 100 nM and 500 nM dose groups respectively. Elevated IOP in GC responder eyes was substantiated with a significant increase in myocilin (11.8-fold; p = 0.0002) and fibronectin (eightfold; p = 0.04) expression as compared to vehicle-treated eyes by immunofluorescence analysis. This is the first study reporting the GC responsiveness in Indian cadaveric eyes. The observed GC response rate was comparable with the previous studies and hence, this model will enable us to investigate the relationship between differential gene expression and individual GC responsiveness in our population.

Preventing glaucoma progression using the trabecular micro-bypass implant iStent inject®. A cost-effectiveness analysis / Prevenindo a progressão do glaucoma por meio do implante de by-pass trabecular iStent inject®. Uma análise de custo-efetividade

ABSTRACT Objective To assess the economic impact of reducing glaucoma progression by using the trabecular micro-bypass implant, iStent inject®, in the Reference Centers for glaucoma treatment within the Brazilian Public Unified Health System (SUS). Methods In a cost-effectiveness analysis, a Markov model was developed, and the costs were obtained from the SUS perspective (medical direct costs). Effectiveness was measured in progression-free life-years. The time horizon was the mean life expectancy of the Brazilian population. The model parameters were obtained through a review and a critical analysis of the literature. The base case comprised a hypothetical cohort of patients with open-angle glaucoma, using anti-glaucoma eye drops and followed up at Reference Centers of SUS. We tested whether the incorporation of iStent inject® as an alternative second-line therapy would be cost-effective. The outcome measure was the incremental cost-effectiveness ratio (R$/progression-free life-years). We tested the robustness of the model by univariate and probabilistic sensitivity analyses. Results The use of iStent inject® led to decreased progression rate of glaucoma, evidenced by the amount of progression-free life-years obtained with each treatment strategy (7.82 progression-free life-years with iStent inject® versus 6.33 progression-free life-years with medical treatment), thereby improving glaucoma control. There was also a reduction in future costs associated with eye drops, filtering surgeries, and treatment complications. Incremental cost-effectiveness ratio ranged from R$ 6,429.30 to R$ 7,550.97/progression-free life-years. The model proved to be robust in the sensitivity analyses. Conclusion This analysis showed that iStent inject®, when used after the failure of the first-line therapy, is able to reduce the rate of glaucoma progression at an acceptable cost.

RESUMO Objetivo Avaliar o impacto econômico da redução da progressão do glaucoma pelo uso do implante de by-pass trabecular iStent inject® no ambiente dos Centros de Referência para tratamento do Sistema Único de Saúde (SUS). Métodos Em uma análise de custo-efetividade, elaborou-se um modelo de Markov, cujos custos foram obtidos a partir da perspectiva do SUS financiador (custos médicos diretos). A efetividade foi medida em anos de vida livres de progressão. O horizonte temporal foi a expectativa de vida média da população brasileira. Os parâmetros do modelo foram obtidos pela revisão e pela análise crítica da literatura. O caso base foi composto de uma coorte hipotética de portadores de glaucoma de ângulo aberto em uso de colírios antiglaucomatosos e em acompanhamento nos Centros de Referência do SUS. Testou-se se a incorporação do iStent inject® como alternativa à segunda linha de tratamento seria custo-efetiva. A medida de desfecho foi a razão de custo-efetividade incremental (R$/anos de vida livres de progressão). A robustez do modelo foi testada por meio de análises de sensibilidade univariada e probabilística. Resultados A utilização do iStent inject® proporcionou uma diminuição da velocidade de progressão do glaucoma, evidenciada pela quantidade de anos de vida livres de progressão obtida com cada estratégia de tratamento (7,82 anos de vida livres de progressão com iStent inject® versus 6,33 anos de vida livres de progressão com tratamento com colírios), melhorando, dessa forma, o controle do glaucoma. Houve ainda redução nos custos futuros associados aos colírios, às cirurgias filtrantes e às complicações do tratamento. A razão de custo-efetividade incremental variou de R$6.429,30 a R$7.550,97/anos de vida livres de progressão. O modelo mostrou-se robusto nas análises de sensibilidade. Conclusão O iStent inject®, quando usado após a falha do primeiro medicamento, é capaz de reduzir a taxa de progressão do glaucoma a um custo aceitável.

2D- and 3D-cultures of human trabecular meshwork cells: A preliminary assessment of an in vitro model for glaucoma study.

A physiologically relevant in vitro human-based model could be the 'gold standard' to clarify the pathological steps involved in glaucoma onset. In this regard, human 3D cultures may represent an excellent starting point to achieve this goal. Indeed, the 3D matrix allows to re-create the in vivo-like tissue architecture, maintaining its functionality and cellular behaviour, compared to the 2D model. Thus, we propose a comparison between the 2D and 3D in vitro models of human trabecular meshwork cells in terms of cellular responses after chronic stress exposure. Our results showed that 3D-cells are more sensitive to intracellular reactive oxidative specie production induced by hydrogen peroxide treatment, compared to 2D cultures. Additionally, in 3D cultures a more accurate regulation of the apoptosis trigger and cell adaptation mechanisms was detected than in 2D models. In line with these findings, the 3D-HTMC model shows the ability to better mimic the in vivo cell behaviour in adaptive responses to chronic oxidative stress than 2D.

Comparison of spectral domain and swept source optical coherence tomography for angle assessment of Chinese elderly subjects.

BACKGROUND: This comparative study aimed to demonstrate the differences between swept source OCT (SS-OCT) (1310 nm) and spectral domain OCT (SD-OCT) (840 nm) for the identification and measurement of anterior chamber angle (ACA) structures. METHODS: Sixty seven eyes from 67 healthy subjects underwent ACA imaging at the nasal and temporal sides using SS-OCT and SD-OCT with different wavelength (Tomey, 1310 nm and RTvue, 840 nm). Images were evaluated for the ability to distinguish angle structures including the Schwalbe's line (SL), the Schlemm's canal (SC) and the scleral spur (SS). The length of trabecular meshwork (LTM), the angle-opening distance (AOD500 and AOD750) and the length of Schlemm's canal (LSC) were also measured. RESULTS: The nasal identification rate for SL, SC and SS were 91.04%/89.55%, 50.75%/40.30% and 100.0%/74.63% (SS-OCT/SD-OCT), respectively. The temporal identification rate for SL, SC and SS were 86.57%/91.04%, 68.66%/70.15% and 100.0%/65.67% (SS-OCT/SD-OCT), respectively. Differences between SS-OCT and SD-OCT were found in terms of the visualization of the SS. With respect to the measurements of angle, the evaluation of LTM at the nasal side, LSC at the temporal side and AOD500/750 at both sides showed significant difference between the two devices. However, there existed good correlation between the AOD500/750 measured by SS-OCT and SD-OCT (Spearman's rank correlation coefficient > 0.8, p < 0.000). CONCLUSIONS: SS-OCT displayed a better performance in detecting deeper structures of the angle such as the SS. However, for discriminating structures lying in transparent or semi-transparent tissue such as the SL and the SC, the two devices showed good consistency. Although SS-OCT and SD-OCT demonstrated high correlation for angle measurement (AOD500/750), their agreement was poor.

Assessment of Transport of Lipid Metabolites Within Trabecular Meshwork Cells.

Lipids from trabecular meshwork (TM) cells are of particular interest to ophthalmological researchers as a therapeutic target for lowering intraocular pressure (IOP) in glaucomatous eyes. Fluorescence-based lipid transport assays (FBLTA) and immunocytochemistry (ICC) are dynamic fluorescence analysis techniques that allow for quantitative and qualitative comparisons, respectively, between multiple samples. Here we describe methods for FBLTA, ICC, and mass spectroscopy designed to measure the kinetics and localization of lipid metabolites within the trabecular meshwork.

Assessment of Circumferential Angle Closure with Swept-Source Optical Coherence Tomography: a Community Based Study.

PURPOSE: To evaluate the diagnostic performance of swept-source optical coherence tomography (SS-OCT, CASIA SS-1000; Tomey Corporation, Nagoya, Japan) for angle closure detection, in comparison with gonioscopy, in a community setting. DESIGN: Reliability analysis. METHODS: A total of 2027 phakic subjects aged ≥50 years, with no previous history of glaucoma, laser (including peripheral iridotomy), intraocular surgery, or ocular trauma, were consecutively recruited from a community polyclinic in Singapore. Gonioscopy was performed by a single trained ophthalmologist. SS-OCT angle scans, which obtain radial scans for the entire circumference of the angle, were analyzed by a single examiner, masked to the subject's clinical details. On SS-OCT images, angle closure was defined as contact between the iris and any part of the angle wall anterior to the scleral spur. Different cutoff values of the degree of circumferential angle closure (≥35%, ≥50%, and ≥75%) were taken for analysis to assess SS-OCT performance in detecting angle closure. RESULTS: A total of 1857 subjects (91.6%) were included in the final analysis after excluding poor-quality SS-OCT scans. Almost 90% of the subjects were Chinese, with a mean age of 61.8 ± 6.7 years, and more than half were women (63.5%). The overall AUC of SS-OCT manual grading against gonioscopy was 0.84 (95% confidence interval, 0.81-0.88). The prevalence of angle closure on SS-OCT was 26.1% for the ≥35% definition, with an area under the curve of 0.80 (0.77-0.84), sensitivity of 82.5% (75.3%-88.4%), and specificity of 78.5% (76.5%-80.4%). The first-order agreement coefficient statistics for the 2-quadrant gonioscopic definition of angle-closure with corresponding ≥35%, ≥50%, and ≥75% angle closure definitions for SS-OCT were good at 0.89 (0.83-0.93), 0.88 (0.842-0.93), and 0.88 (0.831-0.99), respectively. CONCLUSIONS: In this large community-based study, SS-OCT exhibited moderate performance for angle closure detection compared to gonioscopy as the reference standard.

Agreement between Pentacam and optical coherence tomography in the assessment of iridocorneal angle width in a large healthy population.

PURPOSE: To analyze the agreement between Pentacam and optical coherence tomography (OCT) in the assessment of trabecular-iris angle (TIA) width in a large population of normal subjects. METHODS: A cross-sectional study was performed in 989 right eyes of 989 healthy subjects. The trabecular-iris angle (TIA) was measured in the temporal and nasal quadrants using the Pentacam (Oculus, Wetzlar, Germany), a device based on Scheimpflug technology and RTVue 100 OCT (Optovue, Fremont, CA, USA). Intraclass correlation coefficients (ICC) and Bland-Altman plots were used to evaluate agreement between these devices. RESULTS: Mean age was 49.1±15.2 years (18-84); 61% were women and spherical error range was -14 to 8.25. TIA could be measured by OCT in 94.9% and 94.1% in the temporal and nasal quadrants, with a mean value of 35.8±13.2 degrees (2.5-78.7) and 35.7±12.9 degrees (2.2-76.8) respectively. TIA was able to be measured by Pentacam in 95.2% and 95% in the temporal and nasal quadrants and means were 35.7±7.3 degrees (11-74.2) and 36.4±8.2 degrees (14.5-64) respectively. An ICC of 0.378 (95% confidence interval [CI], 0.322-0.431) and 0.589 (95% CI 0.546-0.629) for the temporal and nasal quadrants was obtained, showing moderate agreement between the devices. Bland-Altman plots revealed that, compared with OCT, Pentacam tends to overestimate measurements in narrow angles and underestimate these in open angles. CONCLUSIONS: Agreement between OCT and Pentacam was mediocre, indicating the two devices are not interchangeable when used to measure angle width.

Functional assessment of the aqueous humour distal outflow pathways in bovine eyes using time-of-flight magnetic resonance tomography.

The major part of the aqueous humor leaves the eye through the "conventional outflow pathway", consisting of the trabecular meshwork, Schlemm's canal, collector channels, an intrasceral plexus and the episcleral veins. While the trabecular meshwork is well characterized, little is known about anatomical and functional features of the peripheral outflow tract beyond Schlemm's canal. The emergence of minimally-invasive glaucoma surgery directly targeting the outflow resistance in the trabecular meshwork has elicited growing interest in these structures. We used time-of-flight magnetic resonance imaging in ex vivo bovine eyes to map fluid flow under physiological conditions. We were able to identify the peripheral outflow vessels solely by the signal detected from the fluid flow inside their lumina. A question of clinical relevance is, whether localized opening of the trabecular meshwork leads to only localized or to a 360° increase in intrascleral flow. To address this, a goniotomy ab interno was performed in 3 eyes and the flow signal intensity was quantified sectorially. A significant increase in fluid flow was observed in the sector distal to the goniotomy (p = 0.0005) but not in the other sectors (p = 0.1). As a proof of concept we demonstrated that TOF-MRI based detection of flow in the peripheral aqueous outflow tract is feasible. The functional link observed between trabecular meshwork sectors and their distal outflow tract sectors may be relevant for minimally-invasive glaucoma surgery in humans.

Incidence and management of haemorrhagic Descemet membrane detachment in canaloplasty and phacocanaloplasty.

PURPOSE: To report the incidence and management of haemorrhagic Descemet membrane detachment (HDMD) in canaloplasty and phacocanaloplasty. METHODS: This study included 105 eyes of 92 patients with uncontrolled open angle glaucoma who underwent canaloplasty and phacocanaloplasty between 2010 and 2014. Eyes that developed either HDMD or non-HDMD were identified. The main outcome measures were the development of HDMD and non-HDMD, best corrected visual acuity, recovery time after Descemet membrane detachment (DMD), intra-ocular pressure (IOP) and number of antiglaucoma medications. Each eye was managed according to the time of development, type and extent of DMD. RESULTS: Ten eyes (9.5%) developed DMD- four eyes underwent canaloplasty (3.8%) and six eyes underwent phacocanaloplasty (5.7%). Three of 10 eyes developed non-HDMD while seven of 10 developed HDMD, the majority of HDMD cases occurred in combination with phacocanaloplasty (five of seven). The non-HDMD eyes resolved completely within 2 weeks without intervention. One eye with HDMD was observed for 2 weeks, before a 15% sulphur hexafluoride (SF6) intracameral injection was given. The patient developed a dense corneal stain that was resolving slowly over 30 months. One eye with HDMD underwent YAG laser membranotomy 2 weeks after being identified, which regained corneal transparency 1 month after treatment, while the remaining five eyes underwent immediate surgical drainage and regained corneal transparency 1 day post-procedure. CONCLUSION: HDMD occurred in up to 6.7% in canaloplasty and phacocanaloplasty procedures, mostly during catheter withdrawal and the viscodilation step. Early recognition and management prevented further manipulation.

Optical Coherence Tomography Assessment of Angle Anatomy Changes After Trabeculectomy in Primary Angle-Closure Glaucoma.

PURPOSE: Using anterior chamber optical coherence tomography to evaluate changes in angle anatomy in patients with primary angle-closure glaucoma (PACG) before and after trabeculectomy. METHODS: This is a prospective observational study in 38 eyes of 38 patients with PACG, who underwent trabeculectomy. We used customized software to analyze optical coherence tomography images (Visante) of all participants before and after the surgical treatment. Multivariate linear regression analysis was performed for predictors of percentage change in mean angle parameters, including scleral spur angle, angle opening distance, angle recess area, and trabecular-iris surface area. The main outcome measures were changes in angle parameters and their relationship with age, sex, refraction, MD, visual outcomes, central corneal thickness, axial length of eye, number of glaucoma bottles, baseline intraocular pressure (IOP), and percentage changes in IOP (ΔIOP). RESULTS: There was a significant increase in all angle parameters at the follow-up examination compared with the baseline value (all P<0.001). After multivariate analysis, the only variable related to changes in all angle parameters was ΔIOP. CONCLUSIONS: Trabeculectomy results in a significant increase in the angle width in PACG. The increase in angle parameters was significantly related to the IOP changes.

Comparing Gonioscopy With Visante and Cirrus Optical Coherence Tomography for Anterior Chamber Angle Assessment in Glaucoma Patients.

PURPOSE: The aim of this study was to compare gonioscopy with Visante and Cirrus optical coherence tomography (OCT) for identifying angle structures and the presence of angle closure in patients with glaucoma. A secondary objective was to assess interrater agreement for gonioscopy grading among 3 independent examiners. METHODS: Gonioscopy grading using Spaeth Classification and determination of angle-closure risk was performed on 1 randomly selected eye for 50 phakic patients. Images of the same eye using both Visante and Cirrus OCT were obtained in both light and dark conditions. Agreement of angle closure among 3 devices and interrater agreement for gonioscopy were determined using Cohen's κ (K) or Kendall's coefficient of concordance (W). RESULTS: Of the 50 patients, 60% were female, 64% were white, and the mean age was 62 years. Angle closure was detected in 18%, 16%, and 48% of quadrants with Visante, Cirrus, and gonioscopy, respectively. The scleral spur was identified in 56% and 50% of quadrants with Visante and Cirrus OCT, respectively. Visante and Cirrus OCT showed moderate agreement in detecting angle closure (K=0.42 light, K=0.53 dark) but slight-to-fair agreement with gonioscopy (Visante K=0.25, Cirrus K=0.15). Gonioscopy demonstrated substantial agreement in angle closure (K=0.65 to 0.68) and angle-closure risk assessment (W=0.83) among 3 examiners. CONCLUSIONS: Visante and Cirrus OCT imaging may have limited ability to identify angle closure because of difficulty identifying angle structures. Gonioscopy by well-trained clinicians had remarkably consistent agreement for identifying angle-closure risk.

Swept-source optical coherence tomography assessment of iris-trabecular contact after phacoemulsification with or without goniosynechialysis in eyes with primary angle closure glaucoma.

AIMS: To compare the change in iris-trabecular contact (ITC) area using swept-source optical coherence tomography (SS-OCT) in eyes with primary angle closure glaucoma (PACG) and cataract that underwent phacoemulsification (PE) with intraocular lens implantation alone compared with PE with goniosynechialysis (GSL). METHODS: One eye of 22 patients with PACG with peripheral anterior synechiae (PAS) detected by indentation gonioscopy was randomised into two groups (PE alone (n=11) and PE+GSL (n=11)). The anterior chamber angles were evaluated by SS-OCT under dark conditions before and 12 months after surgery using the three-dimensional angle analysis scan protocol that simultaneously obtains 128 cross-sectional radial scans across the anterior chamber at equal intervals (every 1.4°). The ITC area, defined as the area of extent of the circumferential contact of peripheral iris to the angle wall, was computed automatically by SS-OCT after an observer marked the scleral spurs of all 128 scans of each eye. RESULTS: The majority of the 22 subjects were women (77.3%) and the mean±SD age was 67.3±5.8 years. The ITC area was significantly reduced in the PE+GSL group compared with the PE alone group (10.2 mm2 vs. 4.6 mm2, ß=0.54, p=0.03) after adjusting for age, gender, intraocular pressure, extent of PAS and pupil diameter before surgery. Smaller iris volume at baseline was associated with greater ITC area reduction by PE+GSL (ß=-0.728, p=0.03). CONCLUSIONS: Eyes that undergo PE+GSL surgery have a greater reduction in circumferential ITC area than eyes that undergo PE alone.

Anterior Chamber Angle Assessment by Anterior-segment Optical Coherence Tomography After Phacoemulsification With or Without Goniosynechialysis in Patients With Primary Angle Closure Glaucoma.

PURPOSE: To evaluate changes of anterior chamber angle (ACA) by anterior-segment optical coherence tomography (AS-OCT) in patients with primary angle closure glaucoma (PACG) following phacoemulsification (phaco) with or without goniosynechialysis (GSL). METHODS: Patients with PACG recruited into 2 randomized controlled trials comparing phaco-GSL versus phaco were pooled for analysis. Images of ACA were obtained by AS-OCT before surgery, and at 1 and 2 weeks, and 1, 3, and 6 months after surgery. The following parameters were analyzed: angle opening distance (AOD) at 500 and 750 µm from the scleral spur, trabecular-iris space area (TISA) at 500 and 750 µm, angle recess area (ARA) at 500 and 750 µm, and scleral spur angle (SSA). RESULTS: All parameters of ACA increased significantly after phaco-GSL (P<0.001), whereas no increase occurred in the phaco group. Negatively significant correlations were found in ΔAOD500 (P<0.05), ΔARA750 (P<0.05), ΔTISA500 (P<0.05), and ΔTISA750 (P<0.05) at 1, 3, and 6 months, and ΔSSA (P<0.05) at 3 and 6 months after phaco-GSL against Δ intraocular pressure (IOP). In the phaco-GSL group, 23 of 23 eyes had IOP<21 mm Hg without any antiglaucoma medication postoperatively. In the phaco group, 12 of 20 eyes (60%) had IOP<21 mm Hg without medication, 8 of 20 eyes required medication with IOP<21 mm Hg (15%) and uncontrollable IOP (25%) after surgery. CONCLUSIONS: On AS-OCT evaluation, ACA in eyes with PACG opened and widened significantly after phaco-GSL in our study. It is suggested that ΔAOD500, ΔARA750, ΔTISA500, ΔTISA750, and ΔSSA would provide valuable information to estimate the effectiveness of phaco-GSL.

Assessment of circumferential angle-closure by the iris-trabecular contact index with swept-source optical coherence tomography.

PURPOSE: To evaluate the diagnostic performance of the iris-trabecular contact (ITC) index, a measure of the degree of angle-closure, using swept-source optical coherence tomography (SSOCT, CASIA SS-1000, Tomey Corporation, Nagoya, Japan) in comparison with gonioscopy. DESIGN: Prospective observational study. PARTICIPANTS: A total of 108 normal subjects and 32 subjects with angle-closure. METHODS: The SSOCT 3-dimensional angle scans, which obtain radial scans for the entire circumference of the angle, were performed under dark conditions and analyzed using customized software by a single examiner masked to the subjects' clinical details. The ITC index was calculated as a percentage of the angle that was closed on SSOCT images. First-order agreement coefficient (AC1) statistics and area under the receiver operating characteristic curve (AUC) analyses were performed for angle-closure on the basis of the ITC index in comparison with gonioscopy. MAIN OUTCOME MEASURES: Angle-closure on gonioscopy was defined as nonvisibility of posterior trabecular meshwork for at least 2 quadrants. Agreement of the ITC index with gonioscopically defined angle-closure was assessed using the AC1 statistic. RESULTS: Study subjects were predominantly Chinese (95.7%) and female (70.7%), with a mean age of 59.2 (standard deviation, 8.9) years. The median ITC index was 15.24% for gonioscopically open-angle eyes (n = 108) and 48.5% for closed-angle eyes (n = 32) (P = 0.0001). The agreement for angle-closure based on ITC index cutoffs (>35% and ≥50%) and gonioscopic angle-closure was 0.699 and 0.718, respectively. The AUC for angle-closure detection using the ITC index was 0.83 (95% confidence interval, 0.76-0.89), with an ITC index >35% having a sensitivity of 71.9% and specificity of 84.3%. CONCLUSIONS: The ITC index is a summary measure of the circumferential extent of angle-closure as imaged with SSOCT. The index had moderate agreement and good diagnostic performance for angle-closure with gonioscopy as the reference standard.