Management of advanced glaucoma: Characterization and monitoring

Assessing the economic burden of vision loss and irreversible legal blindness in Spain (2021-2030): a societal perspective

OBJECTIVE

To estimate the economic impact for the society, generated as a consequence of the onset of loss of vision and irreversible legal blindness, for the main ophthalmologic diseases in Spain: glaucoma, diabetic retinopathy (DR), diabetic macular edema (DME), age-related macular degeneration (AMD) and high myopia (HM).

METHODS

A cost analysis model was developed to estimate the economic burden of glaucoma, DR, DME, AMD and HM over a 10-year time horizon (2021-2030), from a societal perspective in Spain. The epidemiological and economic parameters used in the model were obtained through a literature review. Prevalence, incidence, and progression stages were used to establish the epidemiological flows. Annual costs per patient from publications were included and classified into direct healthcare, direct non-healthcare and indirect costs. Costs from other countries were converted based on purchasing-power-parity (€EUR, PPP). Epidemiological parameters about population and cost results were validated by a panel of experts. All costs were adjusted to euros, 2021 (€, 2021), and using the Consumer Price Index (CPI) of the last 10 years, extrapolated to 2030 euros (€, 2030).

RESULTS

It was estimated that the total population of patients with the main diseases pathologies (glaucoma, DR, DME, AMD and HM) will increase to 7.99 million patients by 2030, representing an increase of 103%. The total cost by 2030 of all pathologies would amount to 99.8 billion euros. Direct non-healthcare costs account for the largest item (44%), followed by loss of productivity costs (38%), and direct healthcare costs (18%). The pathologies with the highest cumulative costs will be glaucoma (€33.6 billion) and DME (€19.8 billion).The greatest increment costs compared to 2021 will likely be generated by pathologies related to diabetes mellitus, such as DR (703%) and DME (317%).

CONCLUSIONS

Knowing the costs associated with the pathologies that generate loss of vision and irreversible legal blindness is essential to understand the socioeconomic impact associated with these pathologies. Furthermore, the high cost of treating these diseases makes necessary to coordinate efforts between administrations, together with the support of patient associations, to meet their needs.

Correlation of contrast sensitivity with ganglion cell/inner plexiform layer thickness and damage location in glaucoma with varying severity

OBJECTIVES

To investigate the correlation of contrast sensitivity with macular region ganglion cell/inner plexiform layer (GC/IPL) thickness and damage location in open-angle glaucoma (OAG) of varying severity.

METHODS

Cross-sectional study with 106 patients (203 eyes) who had OAG. Contrast sensitivity of each eye evaluated by quick contrast sensitivity function test based on intelligent algorithm. The GC/IPL thickness measured with optical coherence tomography; six sectors were delineated for localization of damage area. All eyes were grouped by the healthy macular sector and divided into pre-perimetric, early, moderate, and advanced stages, according to severity of visual field impairment.

RESULTS

Mean GC/IPL thickness in the entire macular region and each sector were correlated with parameters that reflected contrast sensitivity (p < 0.01). The structure-function correlations were stronger nasally compared with temporally, and superiorly compared with inferiorly. Eyes with normal structure in inferior temporal sector had less visual field (p' = 0.024) and macular damage (p' = 0.034) compared with eyes that had healthy superior nasal sector; there was no difference in contrast sensitivity (p = 0.898). The structure-function correlations were significant in early, moderate, and advanced glaucoma (p < 0.05) but not in pre-perimetric glaucoma (p = 0.116).

CONCLUSIONS

GC/IPL thinning in all sectors of the macular region in OAG was correlated with contrast sensitivity impairment, whereas the inferior temporal sector was least affected. Contrast sensitivity was supported as a severity evaluation indicator of early, moderate, and advanced glaucoma, but not of pre-perimetric glaucoma.

Differentiating stages of functional vision loss from glaucoma using the Disc Damage Likelihood Scale and cup:disc ratio

BACKGROUND

Glaucoma staging is critical for treatment planning but has rarely been tested in severe/end-stage disease. We compared the performance of the Disc Damage Likelihood Scale (DDLS) and cup:disc ratio (CDR) using a functional glaucoma staging system (GSS) as the reference standard.

METHODS

Post hoc analysis of a randomised controlled trial at the Eye Department of Kilimanjaro Christian Medical Centre, Tanzania. Eligible participants (aged ≥18 years) with open-angle glaucoma, intraocular pressure (IOP) of >21 mm Hg, were randomised to timolol 0.5% eye drops or selective laser trabeculoplasty. Fundoscopy established vertical and horizontal CDRs and DDLS. Visual acuity and static visual fields were graded (GSS). The study used area under the receiver operating characteristic (AROC) curves and Spearman's rank correlation coefficients to compare staging systems. Logistic regression with generalised estimating equations determined risk factors of functional severe/end-stage glaucoma.

RESULTS

382 eyes (201 participants) were evaluated; 195 (51%) had severe or end-stage glaucoma; mean IOP was 26.7 (SD 6.9) mm Hg. DDLS yielded an AROC of 0.90 (95% CI 0.87 to 0.93), vertical cup:disc ratio (vCDR) of 0.88 (95% CI 0.85 to 0.91, p=0.048) for identifying severe/end-stage disease. Correlation coefficients comparing GSS to DDLS and vCDRs were 0.73 and 0.71, respectively. Advanced structural stages, vision impairment, higher IOP and less financial resources were risk factors of functional severe/end-stage glaucoma.

CONCLUSION

This study indicates that both structural staging systems can differentiate severe/end-stage glaucoma from less severe disease, with a moderate advantage of DDLS over CDR. Clinical examination of the optic disc plays an important role in addition to functional assessment when managing severe/end-stage glaucoma.

LIMBARE: An Advanced Linear Mixed-Effects Breakpoint Analysis With Robust Estimation Method With Applications to Longitudinal Ophthalmic Studies

Purpose

Broken stick analysis is a widely used approach for detecting unknown breakpoints where the association between measurements is nonlinear. We propose LIMBARE, an advanced linear mixed-effects breakpoint analysis with robust estimation, especially designed for longitudinal ophthalmic studies. LIMBARE accommodates repeated measurements from both eyes and over time, and it effectively addresses the presence of outliers.

Methods

The model setup of LIMBARE and the computing algorithm for point and confidence interval estimates of the breakpoint were introduced. The performance of LIMBARE and other competing methods was assessed via comprehensive simulation studies and application to a longitudinal ophthalmic study with 216 eyes (145 subjects) followed for an average of 3.7 ± 1.3 years to examine the longitudinal association between structural and functional measurements.

Results

In simulation studies, LIMBARE showed the smallest bias and mean squared error for estimating the breakpoint, with an empirical coverage probability of corresponding confidence interval estimates closest to the nominal level for scenarios with and without outlier data points. In the application to the longitudinal ophthalmic study, LIMBARE detected two breakpoints between visual field mean deviation (MD) and retinal nerve fiber layer thickness and one breakpoint between MD and cup-to-disc ratio, whereas the cross-sectional analysis approach detected only one and none, respectively.

Conclusions

LIMBARE enhances breakpoint estimation accuracy in longitudinal ophthalmic studies, and the cross-sectional analysis approach is not recommended for future studies.

Translational Relevance

Our proposed method and companion R package provide a valuable computational tool for advancing longitudinal ophthalmology research and exploring the association relationships among ophthalmic variables.

Ex-PRESS Implantation versus Trabeculectomy for Long-Term Maintenance in Patients with Open-Angle Glaucoma

Purpose

To compare the efficacy of Ex-PRESS implantation (EXP) with that of trabeculectomy (TLE) with mitomycin C for maintaining low target intraocular pressure (IOP) in patients with open-angle glaucoma.

Patients and Methods

Patients were randomly assigned to receive EXP or TLE. Surgical success was defined according to three target mean IOP ranges (5 mmHg ≤ IOP ≤ 18 mmHg [criterion A], 5 mmHg ≤ IOP ≤ 15 mmHg [criterion B], and 5 mmHg ≤ IOP ≤ 12 mmHg [criterion C]) representing reductions of at least 20% below the baseline on two consecutive follow-up visits 3 months post-surgery, with or without antiglaucoma medication and without further glaucoma surgery. Participants were divided into three subgroups based on baseline mean deviation (MD) values: early (MD ≥ -6 dB), moderate (-6 dB > MD ≥ -12 dB), and advanced (-12 dB > MD). Survival rates were calculated by subgroup.

Results

A total of 73 patients, including 30 in the EXP group and 43 in the TLE group, were included in the study. No significant differences in baseline ocular or demographic characteristics were found between the two groups. No significant difference in IOP was noted every 6 months. After the 3-year follow-up, success rates were A) 60.0% and 60.2%, B) 45.7% and 58.1%, and C) 31.5% and 40.5% for the EXP and TLE groups, respectively. Moreover, there was no difference in success rate based on glaucoma level. Many glaucoma medications administered before surgery were associated with a higher failure rate in the TLE group but not in the EXP group.

Conclusion

Both procedures resulted in similar IOP reductions and success rates for a low target IOP. The number of preoperative glaucoma medications was a risk factor for TLE failure.

Relationship between the Macular Microvasculature and Central Visual Field Sensitivity in Patients with Advanced Glaucoma

PURPOSE

To evaluate the relationship between central visual field sensitivity (cVFS) and the structural parameters in patients with advanced glaucoma.

DESIGN

Cross-sectional study.

METHODS

In total, 226 eyes of 226 patients with advanced glaucoma were classified into the "minor central defect" (mean deviation on 10-2 visual field test [MD10] > -10 dB) and "significant central defect" (MD10 ≤ -10 dB) groups. We examined the structural parameters using RTVue OCT and angiography, including the retinal nerve fiber layer, ganglion cell complex, peripapillary vessel density (VD), and superficial and deep macular VD (mVD). The assessment of cVFS included MD10 and the mean deviation of the central 16 points on the 10-2 VF test (MD16). We used Pearson correlation and segmented regression to assess the global and regional relationships between the structural parameters and cVFS.

MAIN OUTCOME MEASURES

Correlation between structural parameters and cVFS.

RESULTS

In the minor central defect group, the best global correlations existed between the superficial macular and parafoveal mVD and MD16 (r = 0.52 and 0.54, P < 0.001). In the significant central defect group, superficial mVD best correlated with MD10 (r = 0.47, P < 0.001). Segmented regression between superficial mVD and cVFS revealed no breakpoint was found as MD10 declined, but a breakpoint was identified at -5.95 dB for MD16, which was statistically significant (P < 0.001). The regional correlations between the grid VD and sectors of the central 16 points were significant (r = 0.20-0.53, P= 0.010 ∼P < 0.001).

CONCLUSIONS

The fair global and regional relationships between mVD and cVFS suggest that mVD may be beneficial for monitoring cVFS in patients with advanced glaucoma.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Usability and Clinician Acceptance of a Deep Learning-Based Clinical Decision Support Tool for Predicting Glaucomatous Visual Field Progression

PRCIS

We updated a clinical decision support tool integrating predicted visual field (VF) metrics from an artificial intelligence model and assessed clinician perceptions of the predicted VF metric in this usability study.

PURPOSE

To evaluate clinician perceptions of a prototyped clinical decision support (CDS) tool that integrates visual field (VF) metric predictions from artificial intelligence (AI) models.

METHODS

Ten ophthalmologists and optometrists from the University of California San Diego participated in 6 cases from 6 patients, consisting of 11 eyes, uploaded to a CDS tool ("GLANCE", designed to help clinicians "at a glance"). For each case, clinicians answered questions about management recommendations and attitudes towards GLANCE, particularly regarding the utility and trustworthiness of the AI-predicted VF metrics and willingness to decrease VF testing frequency.

MAIN OUTCOMES AND MEASURES

Mean counts of management recommendations and mean Likert scale scores were calculated to assess overall management trends and attitudes towards the CDS tool for each case. In addition, system usability scale scores were calculated.

RESULTS

The mean Likert scores for trust in and utility of the predicted VF metric and clinician willingness to decrease VF testing frequency were 3.27, 3.42, and 2.64, respectively (1=strongly disagree, 5=strongly agree). When stratified by glaucoma severity, all mean Likert scores decreased as severity increased. The system usability scale score across all responders was 66.1±16.0 (43rd percentile).

CONCLUSIONS

A CDS tool can be designed to present AI model outputs in a useful, trustworthy manner that clinicians are generally willing to integrate into their clinical decision-making. Future work is needed to understand how to best develop explainable and trustworthy CDS tools integrating AI before clinical deployment.

Detecting disease progression in mild, moderate and severe glaucoma

PURPOSE OF REVIEW

The purpose of this review is to examine contemporary techniques for detecting the progression of glaucoma. We provide a general overview of detection principles and review evidence-based diagnostic strategies and specific considerations for detecting glaucomatous progression in patients with mild, moderate and severe disease.

RECENT FINDINGS

Diagnostic techniques and technologies for glaucoma have dramatically evolved in recent years, affording clinicians an expansive toolkit with which to detect glaucoma progression. Each stage of glaucoma, however, presents unique diagnostic challenges. In mild disease, either structural or functional changes can develop first in disease progression. In moderate disease, structural or functional changes can occur either in tandem or in isolation. In severe disease, standard techniques may fail to detect further disease progression, but such detection can still be measured using other modalities.

SUMMARY

Detecting disease progression is central to the management of glaucoma. Glaucomatous progression has both structural and functional elements, both of which must be carefully monitored at all disease stages to determine when interventions are warranted.

The Japan Glaucoma Society guidelines for glaucoma 5th edition

We are pleased to bring you the 5th edition of the Glaucoma Clinical Practice Guidelines. Clinical practice guidelines are based on evidence (scientific grounds). It is a document that presents the treatment that is the most appropriate for the patient. "Glaucoma Clinical Guidelines" was first published in 2003. This was the first guideline for glaucoma treatment in Japan. The principle of glaucoma treatment is to lower intraocular pressure. Means for lowering intraocular pressure includes drugs, lasers, and surgery; Glaucoma is a disease that should be considered as a complex syndrome rather than a single condition. Therefore, the actual medical treatment is not as simple as one word. This time we set the Clinical Questionnaire with a focus on glaucoma treatment. We hope that you will take advantage of the 5th edition.

Comparative Analysis of 10-2 Test on Advanced Vision Analyzer and Humphrey Perimeter in Glaucoma

Purpose

To evaluate diagnostic precision and prove equivalence of 2 devices, Advanced vision analyzer (AVA, Elisar Vision Technology) and Humphrey field analyzer (HFA, Zeiss) for the detection of glaucoma on 10-2 program.

Design

Prospective, cross-sectional, observational study.

Participants

Threshold estimates of 1 eye each of 66 patients with glaucoma, 36 control participants, and 10 glaucoma suspects were analyzed on 10-2 test with AVA and HFA.

Methods

Mean sensitivity (MS) values of 68 points and central 16 test points were calculated and compared. Intraclass correlation (ICC), Bland-Altman (BA) plots, linear regression of MS, mean deviation (MD), and pattern standard deviation (PSD) were computed to assess the 10-2 threshold estimate of the devices. Receiver operating characteristic curves were generated for MS and MD values, and the area under the curve (AUC) was compared with assessing diagnostic precision.

Main Outcome Measures

Mean sensitivity values of 68 points and central 16 points, AUC for MS and MD values, ICC values, BA plots, and linear-regression analysis.

Results

Bland-Altman plot showed significant correlation for MS, MD, and PSD values for both devices. For MS, the overall ICC value was 0.96 (P < 0.001) with a mean bias of 0.0 dB and limits of agreement range of 7.59. The difference in MS values between both devices was -0.4760 ± 1.95 (P > 0.05). The AUC for MS values for AVA was 0.89 and for HFA was 0.92 (P = 0.188); whereas it was similar at 0.88 for MD values (P = 0.799). Advanced vision analyzer and HFA identically discriminated between healthy and patients with glaucoma (P < 0.001), although HFA denoted marginally greater ability (P > 0.05).

Conclusions

Statistical results denote adequate equivalence between AVA and HFA because threshold estimates of AVA strongly correlate with HFA for 10-2 program.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

A Prospective Analysis of the Simplified Student Sight Savers Program on Open-Angle Glaucoma Cost Burden in Underserved Communities

(1) Background: Glaucoma is a leading cause of irreversible blindness worldwide. Unfortunately, no noticeable symptoms exist until mid- to late-stage glaucoma, leading to substantial costs to the patient and the healthcare system. (2) Methods: The Student Sight Savers Program, an initiative started at Johns Hopkins University, was designed to meet the needs of community screening for glaucoma. Several medical students at the Rocky Vista University in Saint George, Utah, were trained, and screened patients at local fairs and gathering places using a modified version of this program. Patients found to have elevated pressure (>21 mmHg) or other ocular abnormalities were referred for an ophthalmological examination. (3) Results: Individuals from medically underserved areas/populations (MUA/Ps) were nearly three times as likely to have elevated intraocular pressure as individuals not in underserved areas (p = 0.0141). A further analysis demonstrates that medical students can help reduce medical costs for patients and the healthcare system by providing referrals to ophthalmologists and reaching populations that are not usually screened for glaucoma. (4) Conclusions: Allowing medical students to perform community-based glaucoma screening events in MUA/Ps using handheld tonometers may decrease the cost burden associated with late diagnosis, and raise awareness about glaucoma, especially in underserved populations.

Long-term Intraocular Pressure Fluctuation Is a Risk Factor for Visual Field Progression in Advanced Glaucoma

PRCIS

Intraocular pressure (IOP) fluctuations increase the risk of visual field progression of primary open-angle glaucoma (POAG) in the advanced stage even when IOP is maintained low on average.

PURPOSE

The purpose of this study was to identify risk factors associated with the progression of visual field defect in patients with advanced POAG.

MATERIALS AND METHODS

A retrospective review of medical records was conducted to identify patients who met the Hodapp-Parrish-Anderson criteria for advanced POAG. A total of 122 eyes of 122 patients had undergone IOP measurement with Goldmann applanation tonometer, standard automated perimetry, Cirrus optical coherence tomography, and fundus photography at 6-month intervals. Visual field progression was defined as the deterioration of a minimum of 3 visual field locations more than baseline at 5% levels in 4 consecutive visual fields with 24-2 SITA testing.

RESULTS

Thirty-six eyes of 122 eyes (29.5%, 51.9±13.9 y old) showed visual field progression during 100.7±44.2 months of follow-up. The progression group showed greater long-term IOP fluctuations (2.6±1.4 mm Hg) than the no progression group (53.5±13.5 y; 2.0±1.0 mm Hg, P=0.008). Disc hemorrhage was detected more frequently in the progression group (40.5% vs. 17.4%, P=0.005). Multivariate Cox regression analysis revealed long-term IOP fluctuations [hazard ratio (HR)=2.567, 95% confidence interval (CI): 1.327-5.370, P=0.012] and disc hemorrhage (HR=2.351, 95% CI: 1.120-4.931, P=0.024) to be independent risk factors of visual field progression. Patients who showed both disc hemorrhage and long-term IOP fluctuations were at greater risks of progression (HR=2.675, 95% CI: 1.072-6.457, P=0.035).

CONCLUSIONS

Long-term IOP fluctuations and disc hemorrhage are independent and additive risk factors of visual field progression in advanced glaucoma even at low IOPs. Patients in whom these risk factors are identified require close monitoring and vigorous treatment.

Evaluating Visual Field Progression in Advanced Glaucoma Using Trend Analysis of Targeted Mean Total Deviation

PURPOSE

Trend analysis of visual field (VF) global indices may underestimate the rate of progression in severe glaucoma because of the influence of test points without detectable sensitivity. To test this hypothesis, we compared the rates of change of VF global indices with and without exclusion of undetectable points at various disease stages.

MATERIALS AND METHODS

Six hundred and forty-eight eyes of 366 glaucoma patients with 8 or more reliable 30-2 standard automated perimetry over more than 2 years were enrolled. We calculated targeted mean total deviation (TMTD) by averaging total deviation except points which were consistently undetectable in 3 baseline tests. Eyes were classified as early (≥-6 dB), moderate (-6 dB to -12 dB), advanced (-12 dB to -20 dB), and severe (<-20 dB) based on baseline mean deviation (MD). The rates of change of MD and TMTD in each stage were statistically compared.

RESULTS

Mean age±SD at baseline was 56.9±11.9 years. The MD slope (-0.34 dB/y) in severe glaucoma was significantly slower than TMTD slope (-0.42 dB/y, P=0.028) and was slower than MD slopes in the other stages. Difference between MD slopes and TMTD slopes was most prominent in eyes with MD values less than -25 dB (P=0.002).

CONCLUSIONS

Undetectable locations in eyes with severe glaucoma may underestimate the rates of VF progression. Trend analysis of TMTD rather than global indices offers a practical and simple approach for alleviating underestimation of VF progression in severe glaucoma.

Comparison of the Structure-Function Relationship in Glaucoma Using Optical Microangiography in the Peripapillary Retinal Nerve Fiber Layer

PRCIS

Optical microangiography measurements correlated with functional parameters in glaucoma patients. Optical coherence tomography angiography-derived vessel perfusion density (VPD) better reflected the structure-function relationship than flux index (FI) and retinal nerve fiber layer thickness.

PURPOSE

The purpose of this study was to compare the structure-function relationship between peripapillary optical microangiography (OMAG) measurements and standard automated perimetry (SAP) loss by comparison with peripapillary retinal nerve fiber layer (pRNFL) thickness in primary open-angle glaucoma.

MATERIALS AND METHODS

One eye from each of 128 patients with early-to-severe glaucoma (including preperimetric glaucoma) and 23 normal participants underwent optic nerve head scanning of the radial peripapillary capillaries and pRNFL scans with OMAG centered on the optic disc and SAP (mean age: 67.8±12.0 y; SAP mean deviation: -5.84±6.6 dB). Regional relationships between VPD, FI, pRNFL thickness, and corresponding SAP sensitivity were compared using linear and fractional polynomial (FP) models.

RESULTS

Structure was significantly related to function for all but the nasal pRNFL thickness region. For VPD, the coefficient of determination (R2) using the FP model was significantly stronger than that of the linear model (FP: 0.25 to 0.67, linear: 0.19 to 0.61), while no difference was found for FI in any region (FP: 0.19 to 0.44, linear: 0.15 to 0.42). R2 for VPD was stronger than FI and pRNFL (FP: 0.11 to 0.52, linear: 0.01 to 0.44) in inferior and superior regions, while VPD and FI were not different in temporal and nasal regions.

CONCLUSIONS

VPD showed a stronger association with visual field loss than FI or retinal nerve fiber layer thickness except in the temporal region. The FI relationship was weak but more linear around the peripapillary region. The strength of the structure-function relationship may differ depending on the region of OMAG measurements.

Combining vascular and nerve fiber layer thickness measurements to model glaucomatous focal visual field loss

We compare the focal structure-function correlation of structural measurements of peripapillary retinal nerve fiber layer thickness (RNFL-T) using optical coherence tomography (OCT), capillary density (CD) measurements using OCT-angiography (OCT-A), or a combination of both, with visual field deviation (VFD) in early to advanced glaucoma. Primary open angle glaucoma patients (n = 46, mean ± SD age: 67 ± 10 years; VF mean deviation: -10.41 ± 6.76 dB) were included in this cross-sectional study. We performed 30-2 standard automated perimetry OCT (3.5-mm diameter ring scan) and 15°×15° OCT-A (superficial vascular complex slab). Based on a nerve fiber trajectory model, each VF test spot was assigned to an OCT-A wedge and an OCT ring-sector. Two univariate linear models (M_v and M_t ) using either CD-based vascular (M_v ) or RNFL-T-based thickness information (M_t ) and one multivariate model using both (M_v:t ) were compared in their associations with measured focal VFD, which were higher for the multivariate model M_v:t (mean ± SD correlation coefficient: 0.710 ± 0.086) than for either nested model (0.627 ± 0.078 for M_v and 0.578 ± 0.095 for M_t ). Using a focal visual field approach, the combination of RNFL-T and CD showed better structure-function correlations than thickness or vascular information only.

Temporal contrast adaptation in the analysis of visual function in primary open-angle glaucoma

PURPOSE

To explore the utility of the recovery time (RT) after temporal contrast adaptation in primary open-angle glaucoma (POAG) visual function analysis, especially in severe and end-stage glaucoma, by the Erlanger Flicker Test (EFT).

METHODS

This study included 80 POAG eyes (45 subjects) and 20 normal eyes (20 subjects). POAG eyes were divided into 5 groups. The diagnostic efficacy of the EFT was assessed, and the RT of POAG eyes at different stages was compared. The EFT results were compared with glaucomatous structure and function test results. A nomogram was developed to predict disease progression by the RT and structural indicators.

RESULTS

In the normal eyes, as the test contrast increased, the RT gradually decreased. The EFT test-retest reproducibility was good, with intraclass correlation coefficient values of 0.6 (P < 0.05) for each test contrast. At 12%, 25%, and 35% contrast, the RT in the severe and end-stage glaucoma eyes was significantly prolonged compared with the control group (P < 0.05). The RT at different contrasts was significantly correlated with visual acuity, mean defect, mean sensitivity, and general and individual quadrant optic nerve fiber layer thickness (P ≤ 0.001). The receiver operating curve indicated that RT_12% showed the best overall area under the curve (0.863). We included RT_25% and average optic nerve fiber layer thickness in constructing the nomogram. POAG eyes were further divided into 8 stages. According to the probability distribution, this model showed good performance for visual function analysis in advanced glaucoma.

CONCLUSIONS

Combined with traditional glaucomatous structural and functional parameters, the EFT can be used in the diagnosis and visual function analysis of POAG, especially for severe and end-stage glaucoma. It could be a potential test for disease staging in severe and end-stage glaucoma.

Path to Diagnosis and Clinical Characteristics of Advanced Glaucoma at Initial Diagnosis: a Tertiary Single Center Experience

Purpose: As routine health examinations become more common, many patients first diagnosed with glaucoma have advanced glaucoma. We analyzed the routes to diagnosis and the characteristics of patients initially diagnosed with advanced glaucoma.Methods: We retrospectively retrieved the medical records of patients first diagnosed with advanced glaucoma in our tertiary care center. The inclusion criteria were a mean deviation (MD) less than -12 dB on the visual field test, accompanied by structural damage. All patients were classified in terms of unilateral/bilateral disease, the intraocular pressure before medication, and lens status. We divided patients into those with monocular or binocular advanced glaucoma, high- or normal-pressure glaucoma, and those who were pseudophakic or phakic.Results: We included 73 patients of mean age 69.3 years. The visual field test MD was -19.6 dB. In those with binocular advanced glaucoma, incidental ophthalmic examination was the most common means of diagnosis (52.2%). Central-island visual field defects were the most common defects (54.2%). In those with monocular advanced glaucoma, glaucoma-associated symptoms most commonly triggered diagnosis (46.9%). Both superior and inferiorvisual field defects were the most common defects (42.8%). Glaucoma-associated symptoms were present in 68.2 and 22.8% of patients with high- and normal-pressure glaucoma, respectively. Central-island visual field defects were present in 43.6 and 29.4% of those with high- and normal-pressure glaucoma, respectively.Conclusions: We analyzed the routes to diagnosis and the clinical characteristics of patients with advanced glaucoma. In those with binocular disease, glaucoma was most commonly diagnosed on incidental ophthalmic examination. Central-island visual field defects were the most common defects in patients with binocular and high-pressure glaucoma, and the pseudophakic group. A multi-center longitudinal study on risk factors for delayed glaucoma diagnosis is needed.

Variability and Power to Detect Progression of Different Visual Field Patterns

PURPOSE

To compare the variability and ability to detect visual field (VF) progression of 24-2, central 12 locations of the 24-2 and 10-2 VF tests in eyes with abnormal VFs.

DESIGN

Retrospective, multisite cohort.

PARTICIPANTS

A total of 52 806 24-2 and 11 966 10-2 VF tests from 7307 eyes from the Glaucoma Research Network database were analyzed. Only eyes with ≥ 5 visits and ≥ 2 years of follow-up were included.

METHODS

Linear regression models were used to calculate the rates of mean deviation (MD) change (slopes), whereas their residuals were used to assess variability across the entire MD range. Computer simulations (n = 10 000) based on real MD residuals of our sample were performed to estimate power to detect significant progression (P < 5%) at various rates of MD change.

MAIN OUTCOME MEASURES

Time required to detect progression.

RESULTS

For all 3 patterns, the MD variability was highest within the -5 to -20 decibel (dB) range and consistently lower with the 10-2 compared with 24-2 or central 24-2. Overall, time to detect confirmed significant progression at 80% power was the lowest with 10-2 VF, with a decrease of 14.6% to 18.5% when compared with 24-2 and a decrease of 22.9% to 26.5% when compared with central 24-2.

CONCLUSIONS

Time to detect central VF progression was reduced with 10-2 MD compared with 24-2 and C24-2 MD in glaucoma eyes in this large dataset, in part because 10-2 tests had lower variability. These findings contribute to current evidence of the potential value of 10-2 testing in the clinical management of patients with glaucoma and in clinical trial design.

Aspects of Tertiary Prevention in Patients with Primary Open Angle Glaucoma

The purpose of the study is to assess the health of patients in the activity of tertiary prevention dedicated to preventing blindness caused by POAG (primary glaucoma with open angle and high tension) and NTG (primary glaucoma with open-angle and statistically normal tension-particular form of glaucoma with open angle) and preservation of the remaining visual function. The design of the study is epidemiological, observational, descriptive and retrospective, and uses only the data recorded in the existing records in the archives of the Ophthalmology office within the Integrated Outpatient Clinic of the Emergency Clinical Hospital of Oradea (IOCECHO) during the years 1999-2019 (anamnestic data; objective examination and paraclinical examination: intraocular pressure-IOP and visual field-VF). The methods of the study included the standardized protocol: anamnesis, physical ophthalmological examination, IOP determination, and computerized perimetry with the "Fast Threshold" strategy performed with the "Opto AP-300" perimeter. The obtained results were statistically processed with a specialized software (S.P.S.S.-I.B.M. Statistics version 22). The study examined the available data of 522 patients of which 140 were men (26.8%) and 382 were women (73.2%). The gender ratio was 0.37. In the period 1999-2019, 150,844 people with ophthalmic pathology were consulted in the Ophthalmology office of IOCECHO out of which 522 patients (0.35%) were diagnosed with primitive open-angle glaucoma, 184 people (35.2%) presented high IOP (POAG), and 338 people (64.8%) had statistically normal IOP (NTG). The annual proportion of cases diagnosed with glaucoma in the total number of patients examined was between 0.1% (2005; 2008; 2010) and 2.4% in 2012, when 101 people were detected. In the studied records, no cases of uni- and/or bilateral blindness were mentioned. The mean age of glaucoma patients at the first consultation was 60.81 ± 12.14 years with high frequencies in the 55-69 age groups and at the last consultation it was 66.10 ± 12.47 years with high frequencies in the age groups between 60-74 years. Monitoring and treatment of glaucoma patients was beneficial; IOP decreased statistically significantly: in patients with POAG by 46.16%, from 30.50 ± 7.98 mmHg to 16.42 ± 3.01 mmHg (p = 0.000) and in those with NTG by 17.44%, at 16.39 ± 3.66 mmHg at 13.53 ± 1.92 mmHG (p = 0.000). The duration of treatment and monitoring was on average 5.1 ± 3.4 years, for 184 patients (35.2%) with POAG and 5.1 ± 3.8 years for 338 patients (64.8%) with NTG. Tertiary prevention of glaucoma, by providing specialized care, ensures effective control of IOP and implicitly of the long-term evolution of the disease. IOP is the only modifiable risk factor in patients with POAG and NTG and its decrease prevents the progression of the disease and emphasizes the importance of early diagnosis and treatment. The management of the glaucoma patient consisted of: complete ophthalmological examination (subjective and objective), paraclinical examination with IOP, and VF measurement (valuable ophthalmological diagnostic tool) for disease detection and effective assessment of disease progression in order to improve the process of therapeutic decision making.

Validating tablet perimetry against standard Humphrey Visual Field Analyzer for glaucoma screening in Indian population

Purpose:

The aim of this study was to determine the correlation between the perimetric outcomes using a free application program of the iPad, 'Visual Fields Easy' (VFE), and Humphrey Visual Field Analyzer (HVFA), in normal as well as eyes with glaucomatous damage of varying severity.

Methods:

In this prospective, cross-sectional, observational pilot investigation, visual field testing was carried out in 210 eyes of 210 patients (60 Normal, 150 Glaucoma), using suprathreshold VFE application (Version 8) on the iPad and Standard White-on-White using HVFA. Severity of glaucoma was categorized using Hodapp-Anderson-Parrish criteria for visual field defects. The results of the VFE program were compared to the 24-2 SITA FAST HVFA.

Results:

Data of 210 patients, 100 (47.6%) females, and 110 (52.4%) males, age ranging from 42 to 78 years, Mean 56.64 ± 10.67 years, was analyzed. The Spearman correlation coefficient showed a significant inverse relationship between missed points on the VFE app with MD (S = –0.783) and a parabolic relationship with PSD (S = 0.646) values obtained with the HVFA. As regards missed points, for mild glaucoma, missed points were 37.5, sensitivity was 77.8% and specificity was 52.6%; for moderate glaucoma, missed points were 33.5, sensitivity was 90% and specificity was 48% while for severe glaucoma, missed points were 23, sensitivity was 97% and specificity was 70%. AROC for eyes with mild glaucoma versus normal was 0.419 (95% CI: 0.343-0.495), moderate glaucoma versus normal was 0.705 (95% CI: 0.630-0.780) and severe glaucoma versus normal was 0.857 (95% CI: 0.806-0.908).

Conclusion:

Suprathreshold perimetry using VFE is not suitable as a rapid screening tool for mass screening of glaucoma. VFE cannot be used as a substitute for HVFA in clinic because of its inability to detect early or moderate glaucoma.

Detecting Progression in Advanced Glaucoma: Are Optical Coherence Tomography Global Metrics Viable Measures?

SIGNIFICANCE

Optical coherence tomography (OCT) summary measures have been suggested as a way to detect progression in eyes with advanced glaucoma. Here, we show that these measures have serious flaws largely due to segmentation errors. However, inspection of the images and thickness maps can be clinically useful.

PURPOSE

This study aimed to test the hypothesis that recently suggested global OCT measures for detecting progression in eyes with advanced progression are seriously affected by segmentation mistakes and other errors that limit their clinical utility.

METHODS

Forty-five eyes of 38 patients with a 24-2 mean deviation worse than -12 dB had at least two spectral domain OCT sessions (0.8 to 4.4 years apart) with 3.5-mm circle scans of the disc and cube scans centered on the fovea. Average (global) circumpapillary retinal nerve fiber layer thickness, GcRNFL, and ganglion cell plus inner plexiform layer thickness, GGCLP, were obtained from the circle and cube scan, respectively. To evaluate progression, ΔGcRNFL was calculated for each eye as the GcRNFL value at time 2 minus the value at time 1, and ΔGGCLP was calculated in a similar manner. The b-scans of the six eyes with the highest and lowest ΔGcRNFL and ΔGGCLP values were examined for progression as well as segmentation, alignment, and centering errors.

RESULTS

Progression was a major factor in only 7 of the 12 eyes with the most negative values of either ΔGcRNFL or ΔGGCLP, whereas segmentation played a role in 8 eyes and was the major factor in all 12 eyes with the largest positive values. In addition, alignment (one eye) and other (three eyes) errors played a secondary role in four of the six eyes with the most negative ΔGcRNFL values.

CONCLUSIONS

For detecting the progression of advanced glaucoma, common summary metrics have serious flaws largely due to segmentation errors, which limit their utility in clinical and research settings.

Assessing glaucoma deterioration using Spaeth/Richman contrast sensitivity test

Purpose:

To assess changes in the central and peripheral contrast sensitivity in severe primary open-angle glaucoma (POAG) patients using a computer-based Spaeth/Richman contrast sensitivity test (SPARCS) over a period of 24 months.

Methods:

Our pilot, observational study included 15 patients (30 eyes) with severe POAG. Visual acuity, intraocular pressure, number of anti-glaucoma drugs, visual fields, and SPARCS score were recorded at first visit and at 12 and 24 months.

Results:

We observed changes in mean deviation (MD) from −19.37 ± 5.04 to −20.63 ± 4.07, mean pattern standard deviation (PSD) from 11.49 ± 2.61 to 11.35 ± 2.01, and mean SPARCS score from 54.97 ± 15.66 to 53.50 ± 16.42. We found no statistically significant difference between visual field parameters and SPARCS scores associated with the number or type of prescribed anti-glaucoma drugs. Spearman’s correlation coefficient of SPARCS at baseline (SPARCS1) versus MD at baseline (MD1) was 0.274 (p = 0.142) and SPARCS1 versus PSD at baseline (PSD1) was −0.163 (p = 0.389). The correlation coefficient between SPARCS at 12 months (SPARCS2) versus MD (MD2) at the same time point was computed to be 0.391 (p = 0.03), whereas SPARCS2 versus PSD at 12 months was −0.212 (p = 0.262). Similarly, we found the coefficient to be 0.336 (p = 0.069) for SPARCS3 (SPARCS at 24 months) versus MD3 (MD at 24 months) and −0.242 (p = 0.197) for SPARCS3 versus PSD3 (PSD at 24 months). Correlation coefficients between SPARCS1/2, SPARCS1/3, MD1/2, MD1/3 PSD1/2, and PSD1/3 were 0.856, 0.865, 0.748, 0.722, 0.497, and 0.562, respectively (p < 0.001). MD changed by 9.46% ± 12.73%, PSD by 0.64% ± 14.03%, and average SPARCS by 3.31% ± 12.73% over 24 months.

Conclusion:

The data from our study indicate the utilitarian application of SPARCS, an inexpensive and readily available tool for monitoring functional deterioration in cases with advanced glaucomatous damage, especially in resource-poor settings. Furthermore, it is a useful and reliable alternative to the imaging modalities where retinal nerve fiber layer measurement can be erroneous in advanced cases secondary to the floor effect.

Visual field progression in patients with severe glaucoma

PURPOSE

To assess the cumulative risk of progression in glaucomatous eyes in the severe stage of disease.

METHODS

This was a retrospective observational study. Patients that had severe damage in at least one eye, as defined by three criteria including a mean deviation of ≤ - 20 dB, were included. Glaucoma progression was defined as a loss of ≥ 2 dB in mean deviation confirmed in three consecutive visual field tests, or a persistent loss of two or more lines of vision-not attributable to non-glaucomatous causes-in three consecutive follow-up examinations. Kaplan-Meier survival analysis was used to assess the cumulative incidence of progression of the first eye to reach endpoint in cases where both eyes were eligible.

RESULTS

A total of 143 eyes from 119 patients, were studied over a mean period of 4.9 ± 2.9 years. Baseline mean deviation was - 25.3 ± 3.6 dB. Twenty-three eyes of 22 patients reached the progression endpoint: 14 eyes by visual field criteria and 9 by visual acuity criteria. The cumulative 5-year risk of progression estimated by Kaplan-Meier analysis was 14.6% (95% confidence interval: 6.1-22.2%).

CONCLUSIONS

In severe glaucoma patients, we found a cumulative incidence of progression of 2.9% per year during the first 5 years of follow-up. Similar incidences have been reported in other studies of glaucoma at different stages of severity.

Depth-resolved variations in visibility of retinal nerve fibre bundles across the retina in enface OCT images of healthy eyes

PURPOSE

Recent developments in optical coherence tomography (OCT) technology enable direct enface visualisation of retinal nerve fibre bundle (RNFB) loss in glaucoma. However, the optimum depth at which to visualise RNFBs across the retina is unknown. We aimed to evaluate the range of depths and optimum depth at which RNFBs can be visualised across the retina in healthy eyes.

METHODS

The central ± 25° retina of 10 healthy eyes from 10 people aged 57-75 years (median 68.5 years) were imaged with spectral domain OCT. Slab images of maximum axial resolution (4 μm) containing depth-resolved attenuation coefficients were extracted from 0 to 193.5 μm below the inner limiting membrane (ILM). Bundle visibility within 10 regions of a superimposed grid was assessed subjectively by trained optometrists (n = 8), according to written instructions. Anterior and posterior limits of RNFB visibility and depth of best visibility were identified for each grid sector. Effects of retinal location and individual eye on RNFB visibility were explored using linear mixed modelling with likelihood ratio tests. Intraclass correlation coefficient (ICC) was used to measure overall agreement and repeatability of grading. Spearman's correlation was used to measure correlation between depth range of visible RNFBs and retinal nerve fibre layer thickness (RNFLT).

RESULTS

Retinal location and individual eye affected anterior limit of visibility (χ² ₍₉₎  = 58.6 and 60.5, both p < 0.0001), but none of the differences exceeded instrument resolution, making anterior limit consistent across the retina and different eyes. Greater differences were observed in the posterior limit of visibility across retinal areas (χ² ₍₉₎  = 1671.1, p < 0.0001) and different eyes (χ² ₍₉₎  = 88.7, p < 0.0001). Optimal depth for visualisation of RNFBs was around 20 µm below the ILM in most regions. It varied slightly with retinal location (χ² ₍₉₎  = 58.8, p < 0.0001), but it was not affected by individual eye (χ² ₍₉₎  = 10.7, p = 0.29). RNFB visibility showed good agreement between graders (ICC 0.89, 95%CI 0.87-0.91), and excellent repeatability (ICC 0.96-0.99). Depth range of visible RNFBs was highly correlated with RNFLT (ρ = 0.9, 95%CI: 0.86-0.95).

CONCLUSIONS

The range of depths with visible RNFBs varies markedly across the healthy retina, consistently with RNFLT. To extract all RNFB information consistently across the retina, slab properties should account for differences across retinal locations and between individual eyes.

Associations of Ganglion Cell-Inner Plexiform Layer and Optic Nerve Head Parameters with Visual Field Sensitivity in Advanced Glaucoma

PURPOSE

To evaluate the associations of optical coherence tomography (OCT)-derived macular ganglion cell-inner plexiform layer thickness (mGCIPLT), circumpapillary retinal nerve fiber layer thickness (cpRNFLT), and optic nerve head (ONH) parameters with visual field (VF) sensitivity in advanced glaucoma.

METHODS

In this cross-sectional study, 102 eyes from 102 patients with advanced glaucoma (defined as a 24-2 VF mean deviation (MD) of ≤-12 dB) were included. mGCIPLT, cpRNFLT, and ONH parameters (including the rim area, average cup-to-disc [C:D] ratio, and vertical C:D ratio) were measured using Cirrus high-definition OCT, and 24-2 and 10-2 VF sensitivity tests were performed using standard automated perimetry. Pearson correlations and linear models were used to analyze relationships between OCT-derived parameters and VF parameters.

RESULTS

The mGCIPLT and rim area were significantly positively correlated with the 24-2 VF MD, 24-2 VF pattern standard deviation, 24-2 VF visual field index, and 10-2 VF MD, but cpRNFLT was not significantly correlated with VF parameters. In addition, the average and vertical C:D ratios were significantly negatively correlated with VF parameters. The mGCIPLT and rim area were significantly positively correlated with the 10-2 VF MD (r ranging between 0.542 and 0.621, p < 0.001), while the average and vertical C:D ratios were significantly negatively correlated with the 10-2 VF MD (r = -0.537, p < 0.001, and r = -0.428, p < 0.001, respectively). Each 1-µm change in the average mGCIPLT was associated with an approximately 0.368-dB change in the 24-2 VF MD and 0.677-dB change in the 10-2 VF MD (R2 = 0.268, p < 0.001, and R2 = 0.385, p < 0.001, respectively). The 10-2 VF MD showed a significantly stronger association with inferonasal mGCIPLT than did the 24-2 VF MD in advanced glaucoma (p = 0.007).

CONCLUSIONS

mGCIPLT and ONH parameters were associated with the severity of VF damage and reflected functional damage better than cpRNFLT in advanced glaucoma. Our results suggested that structural measurements of mGCIPLT and ONH parameters and functional measurement of the 10-2 VF may be useful for monitoring progression in advanced glaucoma.

The effect of Bushen Huoxue method in treating glaucoma: A protocol for systematic review and meta-analysis

BACKGROUND

Glaucoma is a common ophthalmic neurodegenerative disease and the main cause of blindness, which seriously affects the life and work of patients, without more effective treatment for optic nerve damage. Bushen Huoxue (BSHX) method is a traditional Chinese medicine (TCM) therapy that has been widely used as an alternative therapy to treat optic nerve damage in glaucoma patients with growing beneficial effect evidence, however, there is no current systematic review has addressed its effect for glaucoma. This study will conduct a systematic review and meta-analysis of the currently published randomized controlled trials (RCTs) of BSHX method for the treatment of glaucoma, aim to assess the efficacy and safety of BSHX method for patients with glaucoma.

METHODS

We will thoroughly search literatures of RCTs related to BSHX method for glaucoma in PubMed, Medline, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP and Wanfang database and other databases from the establishment of the database to November 2019, with no language restriction. After reviewing the title, abstract and full text, 2 reviewers will independently select the study, extract the data, after assess the risk of bias, we will conduct a meta-analysis of the data extracted from the included RCTs, including total effective rate, intraocular pressure (IOP), visual acuity, visual field, TCM syndrome score, and adverse events. The meta-analysis will be performed using Review Manager 5.3 software and the results will be based on either random effects or fixed effects models, depending on the heterogeneity. Trial sequential analysis (TSA) and Grading of Recommendations, Development and Evaluate system (GRADE) will be conduct to evaluate the reliability and quality of evidence.

RESULTS

The results of the study will be published in a peer-reviewed journal, and provide a reasonable and high-quality evidence for the efficacy and safety of BSHX method for glaucoma.

CONCLUSION

This study will be the first meta-analysis to evaluate the efficacy of BSHX method in the treatment of glaucoma comprehensively, and will to provide helpful evidence for the clinical treatment of this disease.

REGISTRATION

PROSPERO CRD42020159897.

Comparison of Rates of Progression of Macular OCT Measures in Glaucoma

Purpose

The purpose of this study was to compare rates of change of various macular thickness measures and evaluate the influence of baseline damage on macular rates of change.

Methods

One hundred twelve eyes (112 patients) with ≥ 2 years of follow-up and ≥ 5 macular optical coherence tomography (OCT) images and 10-2 visual field (VF) tests were included. OCT measures of interests were full macular thickness (FMT), ganglion cell complex (GCC), ganglion cell/inner plexiform layer (GCIPL), ganglion cell layer (GCL), and outer retinal layer (ORL) thickness in 3° × 3° superpixels. Rates of change were estimated with linear regression and normalized by dividing rates by the average normative superpixel thickness. We compared rates of change and proportion of significantly worsening superpixels (detection rate) and improving superpixels (false discovery rate [FDR]) among macular measures as a function of baseline thickness and 10-2 VF status.

Results

Median (interquartile range [IQR]) baseline VF mean deviation, follow-up time, and number of VFs/OCTs were -7.6 dB (-11.8 to -3.8 dB), 4.5 years (4.0-5.0 years), and 9 (8-10), respectively. Normalized FMT and GCC rates of change were faster and detection rates were higher than GCIPL and GCL (P < 0.001), but FMT had lower FDR than GCC (P = 0.02); faster FMT rates were partially explained by ORL rates of change. GCC detection rates were less likely than GCIPL and GCL rates to decrease with diminishing baseline thickness or worse VF damage. In eyes with 10-2 VF worsening, GCC and GCL demonstrated the fastest rates of change.

Conclusions

GCC measurements are most likely to detect structural worsening along the spectrum of glaucoma severity. Although FMT rates of change are least influenced by baseline thickness, they partially reflect likely age-related ORL changes.

Translational Relevance

GCC thickness measurements seem to be the optimal macular outcome measure for detection of glaucoma deterioration.

Individualized Significance of 24-Hour Intraocular Pressure Curves for Therapeutic Decisions in Primary Chronic Open-Angle Glaucoma Patients

Purpose

Diagnostic 24-hour intraocular pressure curves (IPC) are well established in the management of glaucoma. However, objective criteria for the IPC indication are lacking. The aim of this study was to evaluate the impact of individual patient characteristics and glaucoma-related parameters on therapy decisions after IPC and thus examine their relevance for glaucoma management.

Patients and Methods

Retrospective analysis of adult primary open-angle glaucoma (POAG) patients who underwent an IPC (≥6 IOP measurements in 24 hours). The main exclusion criterion was previous IOP-lowering surgery. IPC-dependent (eg, mean and peak IOP) and IPC-independent parameters (eg, perimetry, RNFL thickness) were analyzed in relation to the therapeutic decision after IPC. Further, these parameters were compared in patient subgroups based on age, glaucoma stage, or therapy intensity.

Results

A total of 101 eyes of 101 patients were included. In general, mean and peak IOP were elevated in patients with a therapeutic change after IPC. These subjects presented differences of IPC-independent parameters (eg, IOP at admission, RNFL thickness, glaucoma stage). Regression analysis results suggested a predictive role of IPC-independent parameters for IPC therapeutic decisions. In subgroups of patients of older age or advanced glaucoma, IPC-independent parameters did not correlate with therapeutic decisions after IPC.

Conclusion

These results support the relevance of IPC in the therapeutic management of POAG. Moreover, the study promotes a personalized classification of patients using selected glaucoma characteristics to objectivize their individual benefit from IPC. Further prospective studies are needed to verify the utility of these parameters and IPC in the management of glaucoma.

Individual Macular Layer Evaluation with Spectral Domain Optical Coherence Tomography in Normal and Glaucomatous Eyes

PURPOSE

To evaluate differences in the thickness of the individual macular layers between early, moderate, and severe glaucomatous eyes and compare them with healthy controls.

PATIENTS AND METHODS

Subjects with glaucoma presenting typical optic nerve head findings, high intraocular pressure with or without visual field (VF) damage and normal controls were included. All participants underwent 24-2 perimetry and spectral-domain OCT. Patients were divided into three groups (early, moderate, and severe) based on the mean deviation of the VF and a healthy control group. The device segmented the layers automatically, and their measurements were plotted using the means of the sectors of the inner (3mm) and outer (6mm) circles of the ETDRS grid.

RESULTS

A total of 109 eyes qualified for the study: 14 in the control group and 52, 18 and 25 in the early, moderate and severe groups, respectively. Mean age was 66.13 (SD=12.38). The mean thickness of the circumpapillary retinal nerve fiber layer (RNFL), total macular thickness (TMT), macular RNFL, ganglion cell layer (GCL) and inner plexiform layer (IPL) were significantly different between the 4 groups, with progressive decrease in thickness. Significant overall difference was found for the inner nuclear layer (INL), and the severe glaucoma group presented thicker measurements than controls and early glaucoma. Outer nuclear layer (ONL) was thinner in severe glaucoma group compared with early glaucoma group.

CONCLUSION

Individual macular layer measurement using the inner and outer circles of the ETDRS grid is useful to evaluate different stages of glaucoma. The INL thickening and ONL thinning in advanced glaucoma should be explored in the future studies.

Normal tension glaucoma in obstructive sleep apnea syndrome: A structural and functional study

This study characterized and evaluated normal tension glaucoma (NTG) in obstructive sleep apnea syndrome (OSAS).In this retrospective, cross-sectional study, all participants were examined with polysomnography (PSG). Functional parameters of standard automated perimetry (SAP) were recorded. Structural parameters in optical coherence tomography angiography (OCTA) included peripapillary superficial vessel density (VD RPC), peripapillary whole-layer (VD NH), and superficial and deep macular area VD. Participants were categorized into perimetric and nonperimetric groups by SAP result. Low reliability of SAP and signal strength index <50 in OCTA were excluded.Severity of OSAS was graded by apnea-hypopnea index (AHI) in PSG. Those with moderate/severe OSAS (AHI ≥ 15, n = 39) had longer neck circumference and shorter ocular axial length than mild OSAS (AHI < 15, n = 14). Furthermore, there was significantly higher AHI and larger neck circumference in the NTG perimetric group (n = 27) than in the control group (n = 26; p < 0.001 and p = 0.047, respectively). Superficial and deep-layer peripapillary and macular area VD significantly decreased in the perimetric group. Overall, structural and functional parameters show that VF PSD was negatively correlated with VD NH and VD RPC (p = 0.007, p = 0.015); and VF MD was positively correlated with VD NH (p = 0.029), but not significantly to VD RPC (p = 0.106).OSAS is a risk factor of NTG. With aid of OCTA, whole-layer retinal capillary dropout supports that the vascular dysregulation of OSAS leads to NTG.

Evaluation of contrast sensitivity in patients with advanced glaucoma: comparison of two tests

AIMS

To evaluate contrast sensitivity (CS) in patients with advanced glaucomatous visual field damage, and to compare two clinical CS tests.

METHODS

This was a cross-sectional test-retest study. Twenty-eight patients with open-angle glaucoma, visual acuity (VA) better than 20/40 and visual field mean deviation (MD) worse than -15 dB were enrolled. Patients underwent VA, visual field and CS testing with the Pelli-Robson (PR) chart and the Freiburg Visual Acuity and Contrast Test (FrACT). Retest measurements were obtained within 1 week to 1 month.

RESULTS

Median (IQR) age and MD were 61.5 (55.5 to 69.2) years and -27.7 (-29.7 to -22.7) dB, respectively. Median (IQR) VA was 0.08 logarithm minimum angle of resolution (0.02 to 0.16), corresponding to 20/25 (20/20 to 20/30). Median (IQR) CS was 1.35 (1.11 to 1.51) log units with the PR chart and 1.39 (1.24 to 1.64) log units with FrACT. VA explained less than 40% of the variance in CS (adjusted R²=0.36). CS estimates of both tests were closely related (rho=0.88, p=0.001), but CS was 0.09 log units higher with FrACT compared with the PR chart, and the 95% repeatability intervals (Bland-Altman) were 46% tighter with the PR chart.

CONCLUSIONS

Despite near-normal VA, almost all patients showed moderate to profound deficits in CS. CS measurement provides additional information on central visual function in patients with advanced glaucoma.

Advanced glaucoma at diagnosis: current perspectives

Presentation with advanced glaucoma is a significant risk factor for lifetime blindness. The asymptomatic nature of glaucoma, particularly in early disease, means that substantial vision loss in one eye does not always translate into a perceptible loss of visual function. This, along with the lack of an effective screening strategy, contributes to late presentation. Those most at risk of presenting with advanced glaucoma have asymptomatic high intraocular pressure (IOP), no family history of glaucoma, are socially disadvantaged, and do not attend sight testing. Patients with glaucoma may have impaired functionality for daily activities, such as reading, walking and driving. Quality of life measures have shown this to be significantly worse in patients with more severe visual field loss, particularly if bilateral. In addition, quality of life decreases faster with further bilateral visual field loss when advanced visual field damage is present. Management of these patients requires disproportionally more resources than those with earlier disease. Both medical and surgical options are used as the initial approach to treat patients presenting with advanced glaucoma. The most recently published National Institute for Health and Care Excellence (NICE) guidelines suggest that patients presenting with advanced disease should be offered trabeculectomy as a primary intervention. However, more evidence is required to determine the best initial management. The Treatment of Advanced Glaucoma Study (TAGS) is being conducted, comparing primary medical management with primary mitomycin C-augmented trabeculectomy for people presenting with advanced open-angle glaucoma. The results of TAGS will provide robust evidence for the most appropriate initial intervention.

Cyclodialysis ab externo with implantation of a collagen implant in surgical management of glaucoma

Glaucoma is one of the main causes of irreversible blindness in the Russian Federation and it is the leading cause of visual impairments among working age population. The primary goal of glaucoma therapy is to preserve the visual function, which is mainly achieved through persistent normalization of IOP by instillation of hypotensive drugs, laser therapy and/or surgery/ In this clinical study safety and efficacy of a glaucoma surgical technique implying valve cyclodialysis ab externo with implantation of a non-absorbable collagen implant (NACI) (Xenoplast, Dubna-Biofarm, Russia) in the supraciliary space were evaluated. All patients exhibited moderate and severe primary open-angle glaucoma (POAG). The efficacy assessment criterias were intraocular pressure (IOP) dynamics, use of hypotensive medications, need for repeat surgical intervention and complications. A total of 26 patients (26 eyes) were operated upon and under observation. Twelve months after surgery, 34% IOP decrease from the baseline level was observed: from 29.5 ± 6.8 to 18.8 ± 4.3 mmHg. The amount of hypotensive medications used reduced from 2.8 ± 0.9 to 0.6 ± 0.9. Applying the criteria recommended by the World Glaucoma Association, complete success was registered in 73.1% of patients and partial success — in 26.9% patients. No surgery ended in a failure through the follow-up period. Post-operatively, one patient developed hyphema, 2 patients had some blood elements in aqueous humor and 1 patient had shallow anterior chamber (AC). The suggested surgical technique proved to be an efficient and safe way to decrease IOP and reduce the number of hypotensive medications and had a minimal number of complications associated with the surgery, therefore it can be recommended as a method of choice in patients with advanced stage POAG.

Contrast-to-Noise Ratios for Assessing the Detection of Progression in the Various Stages of Glaucoma

Purpose

We determine the contrast-to-noise ratios (CNRs) of structural and functional measurements to assess their sensitivity to detect progression in the various stages of glaucoma.

Methods

We calculated the CNRs for the mean peripapillary retinal nerve fiber layer (RNFL) thickness measured by spectral domain optical coherence tomography, and the mean deviation (MD) and visual field index (VFI) determined by standard automated perimetry for the transitions between five stages. Longitudinal data from healthy and glaucomatous eyes from a prospective study were used. Contrast was defined as the change in the mean value of the parameter between two successive stages. Noise was defined as the variability of the parameter and calculated from the residuals of linear regression on the data from five subsequent visits per eye.

Results

We studied 205 eyes from 125 participants (46% men, 54% women). CNRs for different parameters varied considerably across the range of disease severity (0.8–12.2). The RNFL thickness had a higher CNR in the transition from normal to mild glaucoma (12.2) compared to the CNRs of the functional measures (MD 4.1, VFI 4.5). The CNRs for the functional measures were higher in the transition from moderate to advanced (MD 5.2, VFI 5.8) and advanced to severe glaucoma (MD 7.2, VFI 5.8) compared to the RNFL thickness (CNR 0.8 and 3.2, respectively).

Conclusions

The RNFL thickness is more sensitive for detecting glaucomatous progression at the onset of glaucoma compared to the functional measures, while the latter are more sensitive for detecting progression in the later stages of glaucoma.

Translational Relevance

The CNR method can be used to determine which measurement is most sensitive for detecting progression in glaucoma, differentiated for the severity of the disease. Furthermore, it creates a basic toolset for determining the most sensitive measurement in detecting progression not only in glaucoma, but other (ophthalmic) diseases as well.

Detecting Glaucoma Progression Using Guided Progression Analysis with OCT and Visual Field Assessment in Eyes Classified by International Classification of Disease Severity Codes

PURPOSE

To compare the detection and rates of progressive retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) loss with spectral-domain (SD) OCT and visual field (VF) loss using Guided Progression Analysis (GPA; Carl Zeiss Meditec, Dublin, CA) in glaucomatous eyes classified using International Classification of Diseases (ICD) diagnosis codes.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Glaucoma patients with at least 3 years of follow-up and a minimum of 4 SD OCT and 5 reliable VF examinations.

METHODS

Glaucoma severity was classified using ICD, 10th Edition, Clinical Modification, diagnosis codes. Rates of RNFL, macular GCIPL, and VF loss were calculated, and progression estimates were compared using generalized estimating equations and McNemar's tests.

MAIN OUTCOME MEASURES

Progressive RNFL, GCIPL, and VF loss assessed by GPA criteria.

RESULTS

A total of 147 eyes of 116 patients (mean age, 69.9±8.5 years) were included with mean follow-up of 69.67±18.64 months. Overall, 38 of 147 eyes (25.9%) showed RNFL progression, 35 eyes (23.8%) showed GCIPL progression, and 20 eyes (13.6%) showed VF progression. Progression by all 3 methods was noted in 10 eyes (7.0%). Eyes with mild (n = 62) and severe (n = 46) glaucoma showed significantly more progression on SD OCT compared with VF (P < 0.001 and P = 0.004). Retinal nerve fiber layer, GCIPL, and VF progressors showed faster rates of loss in average RNFL, GCIPL, and VF mean deviation compared with nonprogressors (mean ± standard error: -1.47±0.30 μm/year vs. -0.03±0.12 μm/year [P = 0.0001], -1.68±0.34 μm/year vs. -0.29±0.07 μm/year [P = 0.0001], and -1.07±0.20 dB/year vs. -0.19±0.04 dB/year [P = 0.0001], respectively).

CONCLUSIONS

Spectral-domain OCT progression was significantly more common than VF progression in glaucomatous eyes classified with mild and severe disease. Structure and function should be monitored closely across the entire spectrum of glaucoma severity.

Can Macula and Optic Nerve Head Parameters Detect Glaucoma Progression in Eyes with Advanced Circumpapillary Retinal Nerve Fiber Layer Damage?

PURPOSE

To evaluate the ability of OCT optic nerve head (ONH) and macular parameters to detect disease progression in eyes with advanced structural glaucomatous damage of the circumpapillary retinal nerve fiber layer (cRNFL).

DESIGN

Longitudinal study.

PARTICIPANTS

Forty-four eyes from 37 patients with advanced average cRNFL damage (≤60 μm) followed up for an average of 4.0 years.

METHODS

All patients were examined with spectral-domain OCT and visual field (VF) assessment during at least 4 visits.

MAIN OUTCOME MEASUREMENTS

Visual field mean deviation (MD) and VF index. OCT cRNFL (average, superior, and inferior quadrants), ganglion cell-inner plexiform layer (GCIPL) (average, superior, and inferior), rim area, cup volume, average cup-to-disc (C:D) ratio, and vertical C:D ratio.

RESULTS

At baseline, patients had a median VF MD of -10.18 dB and mean cRNFL of 54.55±3.42 μm. The rate of change for MD and VF index were significant. No significant rate of change was noted for cRNFL, whereas significant (P < 0.001) rates were detected for GCIPL (-0.57±0.05 μm/year) and ONH parameters such as rim area (-0.010±0.001 mm²/year).

CONCLUSIONS

Macula GCIPL and ONH parameters may be useful in tracking progression in patients with advanced glaucoma.

Optical Coherence Tomography in the Management of Skull Base Fibrous Dysplasia with Optic Nerve Involvement

BACKGROUND

Fibrous dysplasia (FD) of the skull base can manifest with optic nerve compression. As most patients initially do not experience vision loss, controversy exists whether to proceed with prophylactic surgical decompression or elect for conservative observation. Optical coherence tomography (OCT), a physiologic imaging modality widely used to assess the condition of the retinal nerve fiber layer (RNFL), has been useful in monitoring compressive tumors on the optic nerve. This study evaluated potential use of OCT in management of patients with fibrous dysplasia and optic nerve involvement.

METHODS

Six patients with suspected optic nerve compression who underwent OCT imaging as part of a neuro-ophthalmic examination were reviewed over a 2-year period. Patient records were evaluated for visual examination measures, most notably the presence of optic neuropathy, and radiographic measures on computed tomography. Measures were compared by age-adjusted RNFL thickness (above or below fifth percentile) on OCT imaging.

RESULTS

Two patients were found to have mild optic neuropathy in 1 eye each. Three of 12 eyes fell below the age-adjusted fifth percentile of RNFL thickness. Presence of optic neuropathy was associated with abnormal age-adjusted RNFL thickness but not with optic nerve compression (P = 0.45).

CONCLUSIONS

Abnormal RNFL thickness as measured by OCT better predicted the presence of optic neuropathy than computed tomography alone. OCT may be a valuable imaging modality to monitor patients with fibrous dysplasia for development of optic neuropathy during periods of conservative watchful waiting.

The Estimates of Retinal Ganglion Cell Counts Performed Better than Isolated Structure and Functional Tests for Glaucoma Diagnosis

Purpose

To evaluate the diagnostic accuracy of retinal ganglion cell (RGC) counts as estimated by combining data from standard automated perimetry (SAP) and spectral domain optical coherence tomography (SD-OCT).

Methods

Healthy individuals and glaucoma patients were included in this cross-sectional study. All eyes underwent 24-2 SITA SAP and structural imaging tests. RGC count estimates were obtained using a previously described algorithm, which combines estimates of RGC numbers from SAP sensitivity thresholds and SD-OCT retinal nerve fiber layer (RNFL) average thickness.

Results

A total of 119 eyes were evaluated, including 75 eyes of 48 healthy individuals and 44 eyes of 29 glaucoma patients. RGC count estimates performed better than data derived from SD-OCT RNFL average thickness or SAP mean deviation alone (area under ROC curves: 0.98, 0.92, and 0.79; P < 0.001) for discriminating healthy from glaucomatous eyes, even in a subgroup of eyes with mild disease (0.97, 0.88, and 0.75; P < 0.001). There was a strong and significant correlation between estimates of RGC numbers derived from SAP and SD-OCT (R² = 0.74; P < 0.001).

Conclusion

RGC count estimates obtained by combined structural and functional data showed excellent diagnostic accuracy for discriminating the healthy from the glaucomatous eyes and performed better than isolated structural and functional parameters.

Technology and the Glaucoma Suspect

Purpose

To determine and compare the diagnostic performance of spectral-domain optical coherence tomography (SD-OCT), stereoscopic disc photographs, and automated perimetry as assessed by a group of glaucoma specialists in differentiating individuals with early glaucoma from suspects.

Methods

Forty-six eyes (46 patients) with suspicious optic nerves had previously undergone SD-OCT scans, 24-2 visual fields (VFs), and optic disc photographs. The average VF mean deviation was −1.97 ± 2.09 (SD) dB. Four glaucoma specialists examined the 138 individual diagnostic tests and classified the patient as likely glaucomatous or nonglaucomatous based on the results of a single test. The diagnostic performances of each of the three tests were compared to a previously determined reference standard, based on the consensus of a separate panel of four glaucoma specialists who examined all three tests together.

Results

Among the four specialists, the interobserver agreement across the three diagnostic tests was poor for VF and photos, with kappa (κ) values of 0.13 and 0.16, respectively, and moderate for OCT, with κ value of 0.40. Using panel consensus as reference standard, OCT had the highest discriminative ability, with an area under the curve (AUC) of 0.99 (95% 0.96–1.0) compared to photograph AUC 0.85 (95% 0.73–0.96) and VF AUC 0.86 (95% 0.76–0.96), suggestive of closer performance to that of a group of glaucoma specialists.

Conclusions

Compared to VF and disc photography, SD-OCT, when used alone, had better internal agreement as well as better agreement with the consensus of clinicians using all available data. Future studies should evaluate best practices for SD-OCT interpretation.

Association of Structural and Functional Measures With Contrast Sensitivity in Glaucoma

PURPOSE

To test the hypothesis that structural and functional measures predict contrast sensitivity (CS) outcomes in glaucomatous eyes.

DESIGN

Cross-sectional prospective study.

METHODS

One hundred five eyes of 65 patients who underwent macular spectral-domain optical coherence tomography imaging, 24-2 standard achromatic visual fields (VF), and CS measurement on the same day were enrolled. Association of CS at 4 spatial frequencies (3, 6, 12, and 18 cycles per degree, cpd) with structural and functional outcomes was explored with correlation and regression analyses.

RESULTS

The median (IQR) 24-2 visual field mean deviation was -7.6 (-11.1 to -3.0). Significant correlations were found between CS at 6 cpd and ganglion cell/inner plexiform layer thickness at inferotemporal and inferonasal macular sectors (ρ = 0.222, P = .023 and ρ = 0.209, P = .032, respectively). CS at 6 cpd demonstrated higher correlations with full macular thickness measurements, the strongest of which was with the central macular thickness in the superior 6 × 3-degree region (ρ = 0.311, P = .001). Contrast sensitivity at 6 cpd also had the strongest correlation with mean deviation of the 4 central VF points (ρ = -0.420; P < .001). There was a significant correlation between logMAR visual acuity and contrast sensitivity at 6, 12, and 18 cpd (ρ = -0.306, ρ = -0.348 and ρ = -0.241, P < .013, respectively).

CONCLUSIONS

Structural and functional measures showed a fair relationship with contrast sensitivity. This association was most prominent between full-thickness macular measures or central VF parameters and CS at 6 cpd. Contrast sensitivity was not a reliable surrogate for glaucoma severity in this cross-sectional study.

Improving our understanding, and detection, of glaucomatous damage: An approach based upon optical coherence tomography (OCT)

Although ophthalmologists are becoming increasingly reliant upon optical coherence tomography (OCT), clinicians who care for glaucoma patients are not taking full advantage of the potential of this powerful technology. First, we ask, how would one describe the nature of glaucomatous damage if only OCT scans were available? In particular, a schematic model of glaucomatous damage is developed in section 2, and the nature of glaucomatous damage seen on OCT scans described in the context of this model in section 3. In particular, we illustrate that local thinning of the circumpapillary retinal nerve fiber layer (cpRNFL) around the optic disc can vary in location, depth, and/or width, as well as homogeneity of damage. Second, we seek to better understand the relationship between the thinning of the cpRNFL and the various patterns of sensitivity loss seen on visual fields obtained with standard automated perimetry. In sections 4 and 5, we illustrate why one should expect a wide range of visual field patterns, and iilustrate why they should not be placed into discrete categories. Finally, section 6 describes how the clinician can take better advantage of the information in OCT scans. The approach is summarized in a single-page report, which can be generated from a single wide-field scan. The superiority of this approach, as opposed to the typical reliance on summary metrics, is described.