Use of gonioscopy in medicare beneficiaries before glaucoma surgery

Artificial Intelligence in Anterior Chamber Evaluation: A Systematic Review and Meta-Analysis

PRCIS

In this meta-analysis of 6 studies and 5269 patients, deep learning algorithms applied to AS-OCT demonstrated excellent diagnostic performance for closed angle compared with gonioscopy, with a pooled sensitivity and specificity of 94% and 93.6%, respectively.

PURPOSE

This study aimed to review the literature and compare the accuracy of deep learning algorithms (DLA) applied to anterior segment optical coherence tomography images (AS-OCT) against gonioscopy in detecting angle closure in patients with glaucoma.

METHODS

We performed a systematic review and meta-analysis evaluating DLA in AS-OCT images for the diagnosis of angle closure compared with gonioscopic evaluation. PubMed, Scopus, Embase, Lilacs, Scielo, and Cochrane Central Register of Controlled Trials were searched. The bivariate model was used to calculate pooled sensitivity and specificity.

RESULTS

The initial search identified 214 studies, of which 6 were included for final analysis. The total study population included 5269 patients. The combined sensitivity of the DLA compared with gonioscopy was 94.0% (95% CI: 83.8%-97.9%), whereas the pooled specificity was 93.6% (95% CI: 85.7%-97.3%). Sensitivity analyses removing each individual study showed a pooled sensitivity in the range of 90.1%-95.1%. Similarly, specificity results ranged from 90.3% to 94.5% with the removal of each individual study and recalculation of pooled specificity.

CONCLUSION

DLA applied to AS-OCT has excellent sensitivity and specificity in the identification of angle closure. This technology may be a valuable resource in the screening of populations without access to experienced ophthalmologists who perform gonioscopy.

Patterns and Disparities in Recorded Gonioscopy During Initial Glaucoma Evaluations in the United States

PURPOSE

To assess patterns in gonioscopy during initial glaucoma evaluations in the United States.

DESIGN

Retrospective, case-control study.

METHODS

Patients undergoing initial glaucoma evaluation between 2009-2020 were identified in the Optum Clinformatics DataMart. Initial evaluation was defined as follows: (1) glaucoma suspect, anatomical narrow angle (ANA), or primary/secondary glaucoma diagnosed by an ophthalmologist; (2) continuously observable during a 36-month lookback period; (3) no history of glaucoma medications, laser, or surgical procedures; and (4) optical coherence tomography (OCT) or visual field performed within 6 months of initial diagnosis. Logistic regression models were developed to identify factors associated with no record of gonioscopy based on Current Procedural Terminology (CPT) codes.

RESULTS

Among 198,995 patients, 20.4% and 29.5% had recorded gonioscopy on the day of diagnosis or within 6 months, respectively. On multivariable analysis, odds of recorded gonioscopy within 6 months of initial evaluation was lower (P < .001) among non-Hispanic Whites (OR=0.84) but similar for Blacks (OR=1.02) and Hispanics (OR=0.96) compared with Asians. Age ≥60 years (OR<0.82), pseudophakia/aphakia (OR=0.58), or residence outside of the Northeast region (OR=0.66-0.84) conferred lower odds of recorded gonioscopy (P < .001). Angle closure glaucoma (OR=0.85), secondary glaucoma (OR=0.31), or open angle glaucoma/suspect (OR=0.12/0.24, respectively) patients were less likely to have recorded gonioscopy compared to ANA patients (P < .01).

CONCLUSIONS

More than 70% patients undergoing initial glaucoma evaluation in the United States do not have a record of gonioscopy, especially elderly, non-Hispanic White, and pseudophakic patients in non-Northeast regions. This pattern does not conform to current practice guidelines and could contribute to misdiagnosed disease and suboptimal outcomes.

Practice Patterns and Sociodemographic Disparities in the Clinical Care of Anatomical Narrow Angles in the United States

PURPOSE

To assess treatment and visit patterns among patients with newly diagnosed anatomical narrow angle (ANA) and identify sociodemographic factors associated with disparities in care.

DESIGN

Retrospective practice pattern evaluation study.

METHODS

A total of 263,422 patients diagnosed with ANA between 2007 and 2019 were identified in the Optum Clinformatics Data Mart. Inclusion was limited to newly diagnosed ANA, defined as (1) continuous enrollment during a 2-year lookback period and 1-year study period from first diagnosis; (2) diagnosis by an ophthalmologist or optometrist; and (3) no history of pseudophakia, ANA treatments, or prior primary angle closure glaucoma diagnosis. Outcome measures were treatment with laser peripheral iridotomy (LPI), cataract surgery, or intraocular pressure-lowering medications and number of eye care visits. Logistic and Poisson regression were performed to assess factors associated with treatment and eye care visits, respectively.

RESULTS

Among 52,405 eligible cases, 27.7% received LPI, 13.9% received drops, and 15.1% received cataract surgery. Odds of LPI were higher in Asians and Hispanics (odds ratio [OR] ≥ 1.16, P < .001). Non-Whites had higher odds of drops (OR ≥ 1.19, P < .001), but Hispanics had lower odds of cataract surgery (OR = 0.79, P < .001). The mean number of eye care visits was 2.6±2.1 including the day of diagnosis. Older age and treatment were associated with higher rates of eye care visits (rate ratio > 1.15, P < .001).

CONCLUSION

More than a quarter of patients with newly diagnosed ANA receive treatment with LPI. Racial minorities are more likely to receive ANA-specific treatments but less likely to receive cataract surgery. These differences may reflect racial differences in disease severity and the need for clearer practice guidelines in ANA care.

Assessment of angle closure disease in the age of artificial intelligence: A review

Primary angle closure glaucoma is a visually debilitating disease that is under-detected worldwide. Many of the challenges in managing primary angle closure disease (PACD) are related to the lack of convenient and precise tools for clinic-based disease assessment and monitoring. Artificial intelligence (AI)- assisted tools to detect and assess PACD have proliferated in recent years with encouraging results. Machine learning (ML) algorithms that utilize clinical data have been developed to categorize angle closure eyes by disease mechanism. Other ML algorithms that utilize image data have demonstrated good performance in detecting angle closure. Nonetheless, deep learning (DL) algorithms trained directly on image data generally outperformed traditional ML algorithms in detecting PACD, were able to accurately differentiate between angle status (open, narrow, closed), and automated the measurement of quantitative parameters. However, more work is required to expand the capabilities of these AI algorithms and for deployment into real-world practice settings. This includes the need for real-world evaluation, establishing the use case for different algorithms, and evaluating the feasibility of deployment while considering other clinical, economic, social, and policy-related factors.

Early diagnostics and interventional glaucoma

The glaucoma treatment paradigm is starting to change from a more reactive approach that relies on topical medications to a more proactive approach that leverages procedural interventions. This evolution toward interventional glaucoma has been enabled by a growing array of lower-risk minimally invasive procedures such as laser trabeculoplasty, minimally invasive glaucoma surgery, and procedural pharmaceuticals. A common feature of these glaucoma interventions-as with all glaucoma interventions-is the need for early, prompt, and accurate diagnosis. The present review summarizes new and upcoming developments in glaucoma diagnostics. These include technologies and techniques for home-based intraocular pressure measurement, novel visual field platforms, photography- and optical coherence tomography-based visualization, and artificial intelligence applications. They also include emerging technologies such as mitochondrial flavoprotein fluorescence imaging, detection of apoptosing retinal cells, collector channel visualization, and genetic testing. These diagnostic modalities have the potential to circumvent the limitations of traditional diagnostic methods. By increasing the frequency and feasibility of obtaining valuable glaucoma data with more rapid detection of disease and progression, these diagnostics may enable an interventional approach to glaucoma treatment for the betterment of patient care.

Agreement and Reproducibility of Anterior Chamber Angle Measurements between CASIA2 Built-In Software and Human Graders

PURPOSE

This study evaluated the agreement and reproducibility of ACA measurements obtained using the built-in software of the CASIA2 (Version 3G.1) and the measurements derived from expert clinicians.

METHODS

Healthy volunteers underwent ophthalmological evaluation and AS-OCT examination. ACA measurements derived from automated and manual SS location were obtained using the CASIA2 automated software and clinician identification, respectively. The intraobserver, interobserver reproducibility, CASIA2-human grader reproducibility and CASIA2 repeatability were assessed using intraclass correlation coefficients (ICCs).

RESULTS

The study examined 58 eyes of 30 participants. The CASIA2 software showed excellent repeatability for all ACA parameters (ICC > 0.84). Intraobserver, interobserver, and CASIA2-human grader reproducibility were also excellent (ICC > 0.87). Interobserver agreement was high, except for nasal TISA500, differing between observers 1 and 2 (p < 0.05). The agreement between CASIA2 measurements and human graders was high, except for nasal TISA500, where observer 1 values were smaller (p < 0.05).

CONCLUSION

The CASIA2 built-in software reliably measures ACA parameters in healthy individuals, demonstrating high consistency. Although a small difference was observed in nasal TISA500 measurements, interobserver and CASIA2-human grader reproducibility remained excellent. Automated SS detection has the potential to facilitate evaluation and monitoring of primary angle closure disease.

Refractive Error and Anterior Chamber Depth as Risk Factors in Primary Angle Closure Disease: The Chinese American Eye Study

PRCIS

The risk of primary angle closure disease (PACD) rises rapidly with greater hyperopia while remaining relatively low for all degrees of myopia. Refractive error (RE) is useful for angle closure risk stratification in the absence of biometric data.

PURPOSE

To assess the role of RE and anterior chamber depth (ACD) as risk factors in PACD.

METHODS

Chinese American Eye Study participants received complete eye examinations including refraction, gonioscopy, amplitude-scan biometry, and anterior segment ocular coherence tomography imaging. PACD included primary angle closure suspect (≥3 quadrants of angle closure on gonioscopy) and primary angle closure/primary angle closure glaucoma (peripheral anterior synechiae or intraocular pressure >21 mm Hg). Logistic regression models were developed to assess associations between PACD and RE and/or ACD adjusted for sex and age. Locally weighted scatterplot smoothing curves were plotted to assess continuous relationships between variables.

RESULTS

Three thousand nine hundred seventy eyes (3403 open angle and 567 PACD) were included. The risk of PACD increased with greater hyperopia [odds ratio (OR) = 1.41 per diopter (D); P < 0.001] and shallower ACD (OR = 1.75 per 0.1 mm; P < 0.001). Hyperopia (≥ + 0.5 D; OR = 5.03) and emmetropia (-0.5 D to +0.5 D; OR = 2.78) conferred a significantly higher risk of PACD compared with myopia (≤0.5 D). ACD (standardized regression coefficient = -0.54) was a 2.5-fold stronger predictor of PACD risk compared with RE (standardized regression coefficient = 0.22) when both variables were included in one multivariable model. The sensitivity and specificity of a 2.6 mm ACD cutoff for PACD were 77.5% and 83.2% and of a +2.0 D RE cutoff were 22.3% and 89.1%.

CONCLUSION

The risk of PACD rises rapidly with greater hyperopia while remaining relatively low for all degrees of myopia. Although RE is a weaker predictor of PACD than ACD, it remains a useful metric to identify patients who would benefit from gonioscopy in the absence of biometric data.

Generalisability and performance of an OCT-based deep learning classifier for community-based and hospital-based detection of gonioscopic angle closure

PURPOSE

To assess the generalisability and performance of a deep learning classifier for automated detection of gonioscopic angle closure in anterior segment optical coherence tomography (AS-OCT) images.

METHODS

A convolutional neural network (CNN) model developed using data from the Chinese American Eye Study (CHES) was used to detect gonioscopic angle closure in AS-OCT images with reference gonioscopy grades provided by trained ophthalmologists. Independent test data were derived from the population-based CHES, a community-based clinic in Singapore, and a hospital-based clinic at the University of Southern California (USC). Classifier performance was evaluated with receiver operating characteristic curve and area under the receiver operating characteristic curve (AUC) metrics. Interexaminer agreement between the classifier and two human examiners at USC was calculated using Cohen's kappa coefficients.

RESULTS

The classifier was tested using 640 images (311 open and 329 closed) from 127 Chinese Americans, 10 165 images (9595 open and 570 closed) from 1318 predominantly Chinese Singaporeans and 300 images (234 open and 66 closed) from 40 multiethnic USC patients. The classifier achieved similar performance in the CHES (AUC=0.917), Singapore (AUC=0.894) and USC (AUC=0.922) cohorts. Standardising the distribution of gonioscopy grades across cohorts produced similar AUC metrics (range 0.890-0.932). The agreement between the CNN classifier and two human examiners (Ҡ=0.700 and 0.704) approximated interexaminer agreement (Ҡ=0.693) in the USC cohort.

CONCLUSION

An OCT-based deep learning classifier demonstrated consistent performance detecting gonioscopic angle closure across three independent patient populations. This automated method could aid ophthalmologists in the assessment of angle status in diverse patient populations.

Anterior segment biometric measurements explain misclassifications by a deep learning classifier for detecting gonioscopic angle closure

BACKGROUND/AIMS

To identify biometric parameters that explain misclassifications by a deep learning classifier for detecting gonioscopic angle closure in anterior segment optical coherence tomography (AS-OCT) images.

METHODS

Chinese American Eye Study (CHES) participants underwent gonioscopy and AS-OCT of each angle quadrant. A subset of CHES AS-OCT images were analysed using a deep learning classifier to detect positive angle closure based on manual gonioscopy by a reference human examiner. Parameter measurements were compared between four prediction classes: true positives (TPs), true negatives (TNs), false positives (FPs) and false negatives (FN). Logistic regression models were developed to differentiate between true and false predictions. Performance was assessed using area under the receiver operating curve (AUC) and classifier accuracy metrics.

RESULTS

584 images from 127 participants were analysed, yielding 271 TPs, 224 TNs, 77 FPs and 12 FNs. Parameter measurements differed (p<0.001) between prediction classes among anterior segment parameters, including iris curvature (IC) and lens vault (LV), and angle parameters, including angle opening distance (AOD). FP resembled TP more than FN and TN in terms of anterior segment parameters (steeper IC and higher LV), but resembled TN more than TP and FN in terms of angle parameters (wider AOD). Models for detecting FP (AUC=0.752) and FN (AUC=0.838) improved classifier accuracy from 84.8% to 89.0%.

CONCLUSIONS

Misclassifications by an OCT-based deep learning classifier for detecting gonioscopic angle closure are explained by disagreement between anterior segment and angle parameters. This finding could be used to improve classifier performance and highlights differences between gonioscopic and AS-OCT definitions of angle closure.

Racial and Sociodemographic Disparities in the Detection of Narrow Angles before Detection of Primary Angle-Closure Glaucoma in the United States

PURPOSE

To assess the proportion of newly diagnosed cases of primary angle-closure glaucoma (PACG) with and without prior diagnosis of anatomical narrow angle (ANA) and to identify sociodemographic risk factors for late detection (PACG without prior ANA diagnosis).

DESIGN

Retrospective cohort study.

METHODS

One hundred two thousand six hundred seventeen patients with PACG were identified from the Optum Clinformatics Data Mart Database (2007-2019). Patients with newly diagnosed PACG met the following criteria: (1) diagnosis made by an ophthalmologist, (2) disease observable for at least 12 months before diagnosis, and (3) no history of treatment before diagnosis unless preceded by a diagnosis of ANA. Multivariate logistic regression modeling was performed to identify sociodemographic risk factors for late detection.

MAIN OUTCOME MEASURES

Proportion of patients with newly diagnosed PACG without prior ANA diagnosis and sociodemographic factors associated with late detection.

RESULTS

Thirty-one thousand forty-four patients were eligible. More than 70% of PACG cases were detected without prior ANA diagnosis, regardless of patient age, sex, or race. The odds of late detection were significantly higher (P < 0.001) among men (odds ratio [OR], 1.32; 95% confidence interval [CI], 1.25-1.40), Black patients (OR, 1.25; 95% CI, 1.15-1.37), and patients 80 years of age or older (OR, 1.28; 95% CI, 1.11-1.47) or living in Southern (OR, 1.30; 95% CI, 1.22-1.40) or Pacific (OR, 1.27; 95% CI, 1.16-1.36) regions. Findings were similar for patients with PACG with a record of gonioscopy and treatment or with a 24-month lookback period.

CONCLUSIONS

Most patients who receive a new diagnosis of PACG in the United States do not have a prior diagnosis of ANA. The elderly, men, and Black patients are at higher risk of late detection. A need exists for increased disease awareness among providers and more accessible tools to detect patients at risk of developing PACG.

Potentially Missed Opportunities in Prevention of Acute Angle-Closure Crisis

Importance

If an anatomic narrow angle is not appropriately diagnosed and treated, it can result in acute angle-closure crisis (AACC) and lead to substantial vision loss.

Objective

To identify patients who presented with AACC and assess for factors that may have been associated with risk of developing it.

Design, Setting, and Participants

This population-based retrospective cohort study conducted from January 1, 2001, to December 31, 2015, included a 20% nationwide sample of 1179 Medicare beneficiaries. Patients aged 40 years or older with AACC were identified with billing codes. A 2-year lookback period from the date of initial presentation of AACC was used to identify patients who had at least 1 eye care visit, received a diagnosis of open-angle glaucoma (OAG) or suspected OAG, or received at least 1 medication associated with risk of AACC. Of the patients who had at least 1 eye care visit, those who underwent gonioscopy, received a diagnosis of an anatomic narrow angle before developing AACC, or both were identified.

Main Outcomes and Measures

Proportions of patients who had at least 1 eye care visit, had OAG or suspected OAG, received at least 1 medication associated with risk of AACC, underwent gonioscopy, or received a diagnosis of an anatomic narrow angle before development of AACC.

Results

A total of 1179 patients had a confirmed diagnosis of AACC. The mean (SD) age of patients with AACC was 66.7 (11.8) years (range, 40-96 years), 766 were women (65.0%), 57 were Asian (4.8%), 109 were Black (9.2%), 126 were Latino (10.7%), 791 were White (67.1%), and 96 were other race and ethnicity (8.1%). Of these patients, only 796 (67.5%) consulted an optometrist or ophthalmologist at least once during the 2-year lookback period. A total of 464 individuals (39.4%) had OAG or suspected OAG, and 414 (35.1%) had received at least 1 medication associated with increased risk of AACC before developing it. Of the 796 patients who consulted an optometrist or ophthalmologist in the lookback period, less than one-third underwent gonioscopy in the 2 years before developing AACC (n = 264 [33.2%]), and less than one-half of all patients undergoing gonioscopy received a diagnosis of an anatomic narrow angle (n = 113 [42.8%]). Most patients underwent gonioscopy in the 1 to 4 weeks preceding the AACC.

Conclusions and Relevance

In this group of Medicare patients, there appear to have been multiple opportunities for interventions that may have averted AACC. Interventions aimed at addressing risk factors associated with AACC and improving performance of gonioscopy might be associated with reduced risk for ocular morbidity.

An IRIS® Registry-Based Assessment of Primary Open-Angle Glaucoma Practice Patterns in Academic versus Non-Academic Settings

PURPOSE

To compare patient demographic data; level of severity; and clinical, diagnostic, and surgical practice patterns in patients with primary open-angle glaucoma (POAG) in an academic setting (AS) versus non-academic setting (NAS) using the American Academy of Ophthalmology IRIS® Registry (Intelligent Research in Sight).

METHODS

A retrospective cohort study of IRIS® Registry data that included patients with POAG who were seen between January 2016 and December 2019 and had at least one year of follow-up.

RESULTS

Of 3,707,084 distinct eyes with POAG, 3% (109,920) were included in the academic subcohort and 97% (3,597,164) were included in the non-academic subcohort. Among the findings of greatest note (P < .0001 for all comparisons) were a higher proportion of eyes of Black patients, a higher proportion of eyes with level 3 severity, and a higher mean cup-to-disc ratio in eyes in the AS. The relative frequency of gonioscopy, pachymetry, and visual field testing in conjunction with new patient visits was also notably higher in the AS. For glaucoma surgical procedures, the greatest proportional differences in relative frequency were seen for tube shunt procedures (2.55-fold higher in the AS), iStent and Hydrus procedures (2.52-fold higher in the NAS), and endoscopic cyclophotocoagulation (5.80-fold higher in the NAS).

CONCLUSIONS

Based on IRIS® Registry data, notable differences appear to exist with regard to ethno-racial groups, glaucoma severity, and diagnostic and surgical practice patterns in AS versus NAS. By understanding these differences, potential opportunities exist in the development of educational programs related to clinical and surgical glaucoma care.

Automated Focal Plane Merging From a Stack of Gonioscopic Photographs Using a Focus-Stacking Algorithm

Purpose

The purpose of this study was to investigate the utility of automated focal plane merging with the collection of gonio-photographs with different depths of field (DOF) using an established focus-stacking algorithm.

Methods

A cross-sectional study was conducted at Shimane University Hospital, Izumo, Japan. Sixteen eyes from 16 subjects from the glaucoma clinic were included in this study. Image processing was performed for the images of 16 eyes from 16 angle sector following the successful gonio-photography. The 256 sets of focus-stacked and best-focused images were prepared in random order and were compared for the DOF and informativeness to diagnose angle pathology by masked observers in each set as the subjective assessments. Moreover, the energy of the Laplacian (average |ΔI|), which is an indicator of image sharpness between the photographs with and without the focus-stacking processing was also analyzed with the Laplacian filter as the objective assessment.

Results

The automated image processing was successfully performed in all stacks of images. The significant deepening of DOF and improvement of informativeness achieved in 255 (99.6%) and 216 (84.4%) images (P < 0.0001 for both, sign test) and the energy of the Laplacian also significantly increased in 243 (94.9%) images (P < 0.0001, sign test).

Conclusions

Focal plane merging by the automated algorithm can make the gonio-images deeper focus compared with the paired best-focused images subjectively and objectively, which would be useful for angle pathological assessment in clinical practice.

Translational Relevance

Focal plane merging algorithm for the automated gonio-photography can facilitate the angle assessment by providing informative deep-focus image, which would be useful for glaucoma care.

On Clinical Agreement on the Visibility and Extent of Anatomical Layers in Digital Gonio Photographs

Purpose

To quantitatively evaluate the inter-annotator variability of clinicians tracing the contours of anatomical layers of the iridocorneal angle on digital gonio photographs, thus providing a baseline for the validation of automated analysis algorithms.

Methods

Using a software annotation tool on a common set of 20 images, five experienced ophthalmologists highlighted the contours of five anatomical layers of interest: iris root (IR), ciliary body band (CBB), scleral spur (SS), trabecular meshwork (TM), and cornea (C). Inter-annotator variability was assessed by (1) comparing the number of times ophthalmologists delineated each layer in the dataset; (2) quantifying how the consensus area for each layer (i.e., the intersection area of observers' delineations) varied with the consensus threshold; and (3) calculating agreement among annotators using average per-layer precision, sensitivity, and Dice score.

Results

The SS showed the largest difference in annotation frequency (31%) and the minimum overall agreement in terms of consensus size (∼28% of the labeled pixels). The average annotator's per-layer statistics showed consistent patterns, with lower agreement on the CBB and SS (average Dice score ranges of 0.61-0.7 and 0.73-0.78, respectively) and better agreement on the IR, TM, and C (average Dice score ranges of 0.97-0.98, 0.84-0.9, and 0.93-0.96, respectively).

Conclusions

There was considerable inter-annotator variation in identifying contours of some anatomical layers in digital gonio photographs. Our pilot indicates that agreement was best on IR, TM, and C but poorer for CBB and SS.

Translational Relevance

This study provides a comprehensive description of inter-annotator agreement on digital gonio photographs segmentation as a baseline for validating deep learning models for automated gonioscopy.

Trends in Glaucoma Surgeries Performed by Glaucoma Subspecialists versus Nonsubspecialists on Medicare Beneficiaries from 2008 through 2016

PURPOSE

To characterize the use of laser and incisional glaucoma surgeries among Medicare beneficiaries from 2008 through 2016 and to compare the use of these surgeries by glaucoma subspecialists versus nonsubspecialists.

DESIGN

Retrospective, observational analysis.

PARTICIPANTS

Medicare beneficiaries (n = 1 468 035) undergoing ≥1 laser or incisional glaucoma surgery procedure during 2008 through 2016.

METHODS

Claims data from a 20% sample of enrollees in fee-for-service Medicare throughout the United States were analyzed to identify all laser and incisional glaucoma surgeries performed from 2008 through 2016. We assessed use of traditional incisional glaucoma surgery techniques (trabeculectomy and glaucoma drainage implant [GDI] procedure) and microinvasive glaucoma surgery (MIGS). Enrollee and procedure counts were multiplied by 5 to estimate use throughout all of Medicare. Linear regression was used to compare trends in use of glaucoma surgeries between ophthalmologists who could be characterized as glaucoma subspecialists versus nonsubspecialists.

MAIN OUTCOME MEASURES

Numbers of laser and incisional glaucoma surgeries performed overall and stratified by glaucoma subspecialist status.

RESULTS

The number of Medicare beneficiaries undergoing any glaucoma therapeutic procedure increased by 10.6%, from 218 375 in 2008 to 241 565 in 2016. The total number of traditional incisional glaucoma surgeries decreased by 11.7%, from 37 225 to 32 885 (P = 0.02). The total number of MIGS procedures increased by 426% from 13 705 in 2012 (the first year MIGS codes were available) to 58 345 in 2016 (P = 0.001). Throughout the study period, glaucoma subspecialists performed most of the trabeculectomies (76.7% in 2008, 83.1% in 2016) and GDI procedures (77.7% in 2008, 80.6% in 2016). Many MIGS procedures were performed by nonsubspecialists. The proportions of endocyclophotocoagulations, iStent (Glaukos; San Clemente, CA) insertions, goniotomies, and canaloplasties performed by glaucoma subspecialists in 2016 were 22.0%, 25.2%, 56.9%, and 62.8%, respectively.

CONCLUSIONS

From 2008 through 2016, a large shift in practice from traditional incisional glaucoma surgeries to MIGS procedures was observed. Although glaucoma subspecialists continue to perform most traditional incisional glaucoma surgeries, many MIGS procedures are performed by nonsubspecialists. These results highlight the importance of training residents in performing MIGS procedures and managing these patients perioperatively. Future studies should explore the impact of this shift in care on outcomes and costs.

Diagnosis of Pseudoexfoliation Syndrome in Pseudophakic Patients

OBJECTIVE

The aim of this study was to evaluate the sensitivity and specificity of pseudoexfoliation syndrome diagnosis in pseudophakic patients and potential means of improving it.

METHODS

This prospective, nonrandomized study comprised 41 consecutive patients (41 eyes) scheduled for cataract surgery at a tertiary medical center during 2016 and 2017. Preoperatively, all patients underwent a detailed slit-lamp examination, including gonioscopic assessment of the iridocorneal angle. The examination was performed by a glaucoma specialist who completed an assessment form documenting the presence/absence of clinical signs of pseudoexfoliation syndrome. It was repeated 1-2 weeks postoperatively by a second, masked, glaucoma specialist.

RESULTS

Sixteen patients (39.0%) were diagnosed with pseudoex-foliation syndrome preoperatively. The diagnosis was confirmed postoperatively in 11/16 patients (68.8% sensitivity) and in an additional patient not diagnosed preoperatively (96% specificity). The ability to diagnose pseudoexfoliation syndrome postoperatively was significantly worse than preoperatively (Z = 12.161, p < 0.0001). Pupillary border deposits (75% of cases) and the Sampaolesi line (83.3%) were the cornerstones of the postoperative diagnosis; anterior capsular deposits were evident in only 41.6% of cases diagnosed postoperatively (31.3% of the originally diagnosed cases).

CONCLUSIONS

Underdiagnosis of pseudoexfoliation syndrome is common in pseudophakic patients and may have significant implications for future management. Careful attention to pupillary border anatomy and meticulous gonioscopic assessment of the iridocorneal angle are essential for accurate diagnosis. Preoperative documentation of pseudoexfoliation syndrome could help prevent this diagnostic pitfall.

Evaluation of an Algorithm for Identifying Ocular Conditions in Electronic Health Record Data

Importance

For research involving big data, researchers must accurately identify patients with ocular diseases or phenotypes of interest. Reliance on administrative billing codes alone for this purpose is limiting.

Objective

To develop a method to accurately identify the presence or absence of ocular conditions of interest using electronic health record (EHR) data.

Design, Setting, and Participants

This study is a retrospective analysis of the EHR data of patients (n = 122 339) in the Sight Outcomes Research Collaborative Ophthalmology Data Repository who received eye care at participating academic medical centers between August 1, 2012, and August 31, 2017. An algorithm that searches structured and unstructured (free-text) EHR data for conditions of interest was developed and then tested to determine how well it could detect the presence or absence of exfoliation syndrome (XFS). The algorithm was trained to search for evidence of XFS among a sample of patients with and without XFS (n = 200) by reviewing International Classification of Diseases, Ninth Revision or International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-9 or ICD-10) billing codes, the patient's problem list, and text within the ocular examination section and unstructured (free-text) data in the EHR. The likelihood that each patient had XFS was estimated using logistic least absolute shrinkage and selection operator (LASSO) regression. The EHR data of all patients were run through the algorithm to generate an XFS probability score for each patient. The algorithm was validated with review of EHRs by glaucoma specialists.

Main Outcomes and Measures

Positive predictive value (PPV) and negative predictive value (NPV) of the algorithm were computed as the proportion of patients correctly classified with XFS or without XFS.

Results

This study included 122 339 patients, with a mean (SD) age of 52.4 (25.1) years. Of these patients, 69 002 (56.4%) were female and 99 579 (81.4%) were white. The algorithm assigned a less than 10% probability of XFS for 121 085 patients (99.0%) as well as an XFS probability score of more than 75% for 543 patients (0.4%), more than 90% for 353 patients (0.3%), and more than 99% for 83 patients (0.07%). Validated by glaucoma specialists, the algorithm had a PPV of 95.0% (95% CI, 89.5%-97.7%) and an NPV of 100% (95% CI, 91.2%-100%). When there was ICD-9 or ICD-10 billing code documentation of XFS, in 86% or 96% of the records, respectively, evidence of XFS was also recorded elsewhere in the EHR. Conversely, when there was clinical examination or free-text evidence of XFS, it was documented with ICD-9 codes only approximately 40% of the time and even less often with ICD-10 codes.

Conclusions and Relevance

The algorithm developed, tested, and validated in this study appears to be better at identifying the presence or absence of XFS in EHR data than the conventional approach of assessing only billing codes; such an algorithm may enhance the ability of investigators to use EHR data to study patients with ocular diseases.

Deep Learning Classifiers for Automated Detection of Gonioscopic Angle Closure Based on Anterior Segment OCT Images

PURPOSE

To develop and test deep learning classifiers that detect gonioscopic angle closure and primary angle closure disease (PACD) based on fully automated analysis of anterior segment OCT (AS-OCT) images.

METHODS

Subjects were recruited as part of the Chinese-American Eye Study (CHES), a population-based study of Chinese Americans in Los Angeles, California, USA. Each subject underwent a complete ocular examination including gonioscopy and AS-OCT imaging in each quadrant of the anterior chamber angle (ACA). Deep learning methods were used to develop 3 competing multi-class convolutional neural network (CNN) classifiers for modified Shaffer grades 0, 1, 2, 3, and 4. Binary probabilities for closed (grades 0 and 1) and open (grades 2, 3, and 4) angles were calculated by summing over the corresponding grades. Classifier performance was evaluated by 5-fold cross-validation and on an independent test dataset. Outcome measures included area under the receiver operating characteristic curve (AUC) for detecting gonioscopic angle closure and PACD, defined as either 2 or 3 quadrants of gonioscopic angle closure per eye.

RESULTS

A total of 4036 AS-OCT images with corresponding gonioscopy grades (1943 open, 2093 closed) were obtained from 791 CHES subjects. Three competing CNN classifiers were developed with a cross-validation dataset of 3396 images (1632 open, 1764 closed) from 664 subjects. The remaining 640 images (311 open, 329 closed) from 127 subjects were segregated into a test dataset. The best-performing classifier was developed by applying transfer learning to the ResNet-18 architecture. For detecting gonioscopic angle closure, this classifier achieved an AUC of 0.933 (95% confidence interval, 0.925-0.941) on the cross-validation dataset and 0.928 on the test dataset. For detecting PACD based on 2- and 3-quadrant definitions, the ResNet-18 classifier achieved AUCs of 0.964 and 0.952, respectively, on the test dataset.

CONCLUSION

Deep learning classifiers effectively detect gonioscopic angle closure and PACD based on automated analysis of AS-OCT images. These methods could be used to automate clinical evaluations of the ACA and improve access to eye care in high-risk populations.

Optical sectioning and high resolution visualization of trabecular meshwork using Bessel beam assisted light sheet fluorescence microscopy

Glaucoma, one of the leading causes of blindness, is an eye disease caused by irregularities in the ocular aqueous outflow system causing an elevated intraocular pressure. High resolution imaging of the aqueous outflow system comprising trabecular meshwork is immensely valuable to vision analysts and clinicians in comprehending the disease state for the efficacious analysis and treatment of glaucoma. Currently available ocular imaging devices are unable to deliver high resolution images for the visualization of the trabecular meshwork. A method to obtain high resolution (sub-micrometer) images of the trabecular meshwork using Bessel-Gauss beam scanned light sheet fluorescence microscopy is presented and the optical sectioning capability of this technique to obtain three-dimensional volumetric images of the trabecular meshwork of an intact eye without any physical dissection is demonstrated. Figure: Three-dimensional visualization of trabecular meshwork of porcine eye.

Compliance With Primary Open-angle Glaucoma and Primary Open-angle Glaucoma Suspect Preferred Practice Patterns in a Retail-based Eye Clinic

PURPOSE

To determine the level of adherence to the American Academy of Ophthalmology preferred practice pattern (PPP) guidelines for quality primary open-angle glaucoma (POAG) and POAG suspect (POAGS) care among retail-based optometrists.

METHODS

Patients with a diagnosis of POAG or POAGS who participated in a telemedicine pilot project were included. Patients' charts were evaluated for 15 elements of PPP guidelines for glaucoma care. Results were further stratified by number of follow-up visits and diagnosis.

RESULTS

Of 360 identified patients, 10 elements were documented in over 98%. Documentation of the remaining 5 components was as follows: dilated fundus examination 91.1%, central corneal thickness (CCT) 88.6%, visual field 78.9%, gonioscopy 47.5%, and target intraocular pressure (IOP) 15.6%. in total, 32.8% of patients were seen once, whereas the remaining 67.2% had multiple visits. In patients with multiple visits, providers were more likely to document systemic history (100.0% vs. 97.5%; P=0.0346), review of systems (100.0% vs. 97.5%; P=0.0346), gonioscopy (60.0% vs. 22.0%; P<0.001), CCT (94.2% vs. 77.1%; P<0.001), visual field (97.5% vs. 40.7%; P<0.001), and target IOP (22.4% vs. 1.7%; P<0.001) compared with single visit patients. In stratifying results by diagnosis, POAG patients more often received visual field testing (92.7% vs. 68.9%; P<0.001) and had an established target IOP (35.1% vs. 1.4%; P<0.001) compared with POAGS patients.

CONCLUSIONS

Compliance with PPP guidelines for glaucoma care was very high for most elements but lower for performing dilated fundus examination, CCT, visual field, gonioscopy, and target IOP. This study highlights deficiencies in care likely to hamper the detection of glaucoma progression.

Systematic review of the appropriateness of eye care delivery in eye care practice

BACKGROUND

Health care systems are continually being reformed, however care improvement and intervention effectiveness are often assumed, not measured. This paper aimed to review findings from published studies about the appropriateness of eye care delivery, using existing published evidence and/or experts' practice and to describe the methods used to measure appropriateness of eye care.

METHODS

A systematic search was conducted using Medline, Embase and CINAHL (2006 to September 2016). Studies reporting the processes of eye care delivery against existing published evidence and/or experts' practice were selected. Data was extracted from published reports and the methodological quality using a modified critical appraisal tool. The primary outcomes were percentage of appropriateness of eye care delivery. This study was registered with PROSPERO, reference CRD42016049974.

RESULTS

Fifty-seven studies were included. Most studies assessed glaucoma and diabetic retinopathy and the overall methodological quality for most studies was moderate. The ranges of appropriateness of care delivery were 2-100% for glaucoma, 0-100% for diabetic retinopathy and 0-100% for other miscellaneous conditions. Published studies assessed a single ocular condition, a sample from a single centre or a single domain of care, but no study has attempted to measure the overall appropriateness of eye care delivery.

CONCLUSIONS

These findings indicated a wide range of appropriateness of eye care delivery, for glaucoma and diabetic eye care. Future research would benefit from a comprehensive approach where appropriateness of eye care is measured across multiple conditions with a single methodology, to guide priorities within eye care delivery and monitor quality improvement initiatives.

Perceptions of training in gonioscopy

PURPOSE

To evaluate ophthalmology trainees' perception of their gonioscopy learning experience in the Ophthalmology Specialty Training programme.

MATERIALS AND METHODS

A cross-sectional electronic survey was conducted amongst ophthalmology trainees across London Deaneries. The ten questions survey collected parameters, including training grade, previous level of gonioscopy training, confidence in performing the procedure, level of satisfaction with the training formats received, potential barriers and improvements to the training programme. The respondents were also invited to express any additional comments.

RESULTS

Fifty-seven complete responses were analysed. The respondents included 25 junior trainees (ST1-3) and 32 senior trainees (ST4-7 and fellows). One-fifth of the respondents (11/57) were unconfident in performing gonioscopy, the majority being junior trainees (9/11). Over a quarter of the respondents were dissatisfied with the quantity of the gonioscopy training received. Teaching formats, such as consultant teaching (mean 8.0 ± 0.50), self-directed learning (mean 8.0 ± 0.38) and small-group tutorials (mean 7.6 ± 1.6) were all well received. Overall, lack of clinical time was considered as the major barrier to gonioscopy training; however, lack of training was considered as the major barrier in the low-confidence group.

CONCLUSIONS

This study highlighted ophthalmology trainees' dissatisfaction in the current gonioscopy training curriculum and a lack of confidence in performing the procedure. Appropriate modifications to the Ophthalmology Specialty Training programme could enhance trainees' gonioscopy learning experience.

Automated gonioscopy photography for iridocorneal angle grading

PURPOSE

The aim of this study is to assess the agreement between manual and automated gonioscopy for iridocorneal angle opening.

METHODS

The research is a cross-sectional observational study. Manual and automated gonioscopy were performed to consecutive patients in a glaucoma clinic. Iridocorneal angle opening grading was performed according to Shaffer's classification. Automated gonioscopy was performed with NGS-1 automated gonioscope (NIDEK Co., Gamagori, Japan). The automated gonio-photos were graded by two independent observers. Agreement between automated and manual gonioscopy and also among raters was ascertained by Fleiss' kappa statistic and comparison of area under curve.

RESULTS

In total, 88 eyes of 47 subjects were analysed. Mean age was 63 ± 10 years. Twenty eyes (22.7%) were excluded from grading due to poor quality images. Angle closure was detected in 23.4% with dynamic gonioscopy in comparison with 4.3% using automated image grading. The agreement for angle closure diagnosis between dynamic and automated gonioscopy was low (κ = 0.09 ± 0.10; p = 0.18). The area under curve for detecting eyes with angle closure showed poor accuracy between automated and manual methods (area under curve: 0.53 ± 0.05, 95% confidence interval: 0.44-0.62). There was modest inter-rater agreement for angle opening assessment of automated images with Fleiss' kappa of 0.17 (95% confidence interval: 0.035-0.238).

CONCLUSION

Manual and automated gonioscopy showed only slight agreement for the assessment of iridocorneal angle opening status. Further improvements of the NGS-1 automated gonioscopy and technique are desired for widespread use in a real-life setting.

Primary Angle-Closure Glaucoma With Normal Intraocular Pressure at the First Visit: Its Prevalence and Ocular Characteristics

PURPOSE

To investigate the prevalence of normal intraocular pressure (IOP) at first visit among patients with primary angle-closure glaucoma (PACG) and their ocular characteristics.

PATIENTS AND METHODS

We retrospectively reviewed patients with PACG in a referral center. According to untreated IOP, we divided PACG eyes into 2 groups: those with normal IOP and those with high IOP (>21 mm Hg) at the first visit.

RESULTS

One hundred sixty eyes of 160 Korean PACG patients were included. Sixty percent (97/160) of the patients had normal IOP at their first visit. The PACG patients with initially normal IOP had significantly longer axial length (mean±SD, 22.99±0.76 vs. 22.74±0.61) and deeper "true" anterior chamber depth (ACD) (2.09±0.27 vs. 1.82±0.33) than those with initially high IOP (both P<0.05). Multiple logistic regression revealed that deeper "true" ACD (per 0.1 mm; odds ratio, 1.38) and more hyperopic refractive errors (odds ratio, 1.48) were independent predictors of initially normal IOP in PACG eyes (P<0.05). The prevalence of disc hemorrhage was higher in PACG patients with initially normal IOP than in those with initially high IOP (29.9% vs. 14.3%, P=0.029).

CONCLUSIONS

Sixty percent of patients with PACG had normal IOP at their first visit. This suggests that without gonioscopy clinicians may misdiagnose PACG as normal tension glaucoma. ACD measurement can aid the diagnosis of PACG because even PACG eyes with initially normal IOP have shallow ACD.

Contemporary approach to the diagnosis and management of primary angle-closure disease

The primary angle-closure disease spectrum varies from a narrow angle to advanced glaucoma. A variety of imaging technologies may assist the clinician in determining the pathophysiology and diagnosis of primary angle closure, but gonioscopy remains a mainstay of clinical evaluation. Laser iridotomy effectively eliminates the pupillary block component of angle closure; however, studies show that, in many patients, the iridocorneal angle remains narrow from underlying anatomic issues, and increasing lens size often leads to further narrowing over time. Recent studies have further characterized the role of the lens in angle-closure disease, and cataract or clear lens extraction is increasingly used earlier in its management. As a first surgical step in angle-closure glaucoma, lens extraction alone often effectively controls the pressure with less risk of complications than concurrent or stand-alone glaucoma surgery, but may not be sufficient in more advanced or severe disease. We provide a comprehensive review on the primary angle-closure disease nomenclature, imaging, and current laser and surgical management.

Geographic and Demographic Variation in Use of Ranibizumab Versus Bevacizumab for Neovascular Age-related Macular Degeneration in the United States

PURPOSE

To examine demographic and geographic variation in the use of ranibizumab and bevacizumab for the treatment of neovascular age-related macular degeneration (AMD) among Medicare beneficiaries.

DESIGN

Retrospective cohort study.

METHODS

Using a 100% sample of Medicare claims data, we evaluated Medicare beneficiaries (N = 195 812) with an index claim for neovascular AMD between July 1, 2006, and June 30, 2009, to determine whether beneficiaries first received ranibizumab or bevacizumab following initial diagnosis.

RESULTS

The overall proportion of beneficiaries that first received ranibizumab for neovascular AMD was 35%, and varied significantly (0.9%-84.6%) across the 306 US hospital referral regions (median = 33%, interquartile range = 17%-49%). Based on hierarchical logistic regression models, the likelihood of receiving ranibizumab declined over time (adjusted odds ratio (aOR) comparing treatment in 2009 vs 2006 = 0.39, P < .001). After we controlled for year of treatment, black beneficiaries were 45% less likely to receive ranibizumab compared to non-blacks (P < .0001). Beneficiaries residing in urban areas (aOR vs isolated rural towns = 1.12, P < .001), in zip codes with higher median incomes, and in the New England and East South Central census regions (aOR vs Pacific census region = 5.57, P < .001; aOR = 3.58, P < .001, respectively) had increased odds of receiving ranibizumab.

CONCLUSIONS

The odds of receiving bevacizumab vs ranibizumab as initial therapy for neovascular AMD among US Medicare beneficiaries varied substantially across geographic and demographic groups. Relatively fewer patients received ranibizumab for initial neovascular AMD treatment in 2009 vs 2006. Future research should study the drivers of variation in utilization of these interventions, the extent this variation indicates differential access to these agents, and whether treatment choice impacts patient outcomes.

Proportion of undetected narrow angles or angle closure in cataract surgery referrals

OBJECTIVE

To determine the proportion of patients referred for cataract surgery consultation who had undetected narrow angles (primary angle closure suspect [PACS], primary angle closure [PAC], or primary angle closure glaucoma [PACG]).

DESIGN

Retrospective chart review.

PARTICIPANTS

Phakic patients referred by eye care providers (optometrists and ophthalmologists) to a tertiary centre for cataract management between July 1, 2010 and June 30, 2012 were identified and reviewed.

METHODS

Demographic, referral, and specialist assessment information, as well as biometric data, including anterior segment optical coherence tomography, were collected. Patients with undetected narrow angles were identified. Univariate tests and multivariable analyses were performed to determine risk factors for narrow angles or angle closure.

RESULTS

A total of 1229 patients were included. The mean patient age was 67.8 ± 13.0 years, 53.9% of patients were female, and 26.8% were Asian or South Asian. Of the sample population, 139 (11.3%) patients had PACS, 7 (0.6%) had PAC, and 12 (1.0%) had PACG. Overall, 158 (12.9%) patients had narrow angles or angle closure. Multivariable logistic regression using generalized estimating equations confirmed 3 independent predictors of PACS/angle closure: Asian race (odds ratio 2.82, p < 0.001), shorter axial length (AL) (odds ratio 1.25, p = 0.03), and smaller anterior chamber depth (ACD; odds ratio 33.3, p < 0.001). A patient of Asian race referred for cataract surgery with ACD <2.8 mm and AL <23 mm had a 52% probability of having PACS/angle closure (range 42%-62%) versus 3% if these 3 factors were not present.

CONCLUSIONS

Of patients referred for cataract surgery, 1.5% were found to have undetected narrow angles or angle closure, implying that gonioscopy may not be adequately performed in this patient population.

Preclinical imaging of iridocorneal angle and fundus using a modified integrated flexible handheld probe

A flexible handheld imaging probe consisting of a [Formula: see text] charge-coupled device camera, light-emitting diode light sources, and near-infrared laser source is designed and developed. The imaging probe is designed with specifications to capture the iridocorneal angle images and posterior segment images. Light propagation from the anterior chamber of the eye to the exterior is considered analytically using Snell's law. Imaging of the iridocorneal angle region and fundus is performed on ex vivo porcine samples and subsequently on small laboratory animals, such as the New Zealand white rabbit and nonhuman primate, in vivo. The integrated flexible handheld probe demonstrates high repeatability in iridocorneal angle and fundus documentation. The proposed concept and methodology are expected to find potential application in the diagnosis, prognosis, and management of glaucoma.

Undetected angle closure in patients with a diagnosis of open-angle glaucoma

OBJECTIVE

The aim of this study was to identify the proportion of patients referred to a tertiary glaucoma centre with a diagnosis of open-angle glaucoma (OAG) who were found to have angle closure glaucoma.

DESIGN

Retrospective chart review.

METHODS

Consecutive new patients referred for glaucoma management to a tertiary centre between July 2010 and December 2011 were reviewed. Patients whose referrals for glaucoma assessment specified angle status as "open" were included. The data collected included glaucoma specialist's angle assessment, diagnosis, and glaucoma severity. The status of those with 180 degrees or more Shaffer angle grading of 0 was classified as "closed."

RESULTS

From 1234 glaucoma referrals, 179 cases were specified to have a diagnosis of OAG or when angles were known to be open. Of these, 16 (8.9%) were found on examination by the glaucoma specialist to have angle closure. Pseudoexfoliation was present in 4 of 16 patients (25%) in the missed angle-closure glaucoma (ACG) group and 22 of 108 patients (13.5%) in the remaining OAG group. There was no difference found in demographic or ocular biometric parameters between those with confirmed OAG versus those with missed ACG.

CONCLUSIONS

Almost 1 in 11 patients referred by ophthalmologists to a tertiary glaucoma centre with a diagnosis of OAG were in fact found to have angle closure. Given the different treatment approaches for ACG versus OAG, this study suggests a need to strengthen angle evaluations.

Anterior segment imaging in glaucoma: An updated review

Anterior segment imaging allows for an objective method of visualizing the anterior segment angle. Two of the most commonly used devices for anterior segment imaging include the anterior segment optical coherence tomography (AS-OCT) and the ultrasound biomicroscopy (UBM). AS-OCT technology has several types, including time-domain, swept-source, and spectral-domain-based configurations. We performed a literature search on PubMed for articles containing the text “anterior segment OCT,” “ultrasound biomicroscopy,” and “anterior segment imaging” since 2004, with some pertinent references before 2004 included for completeness. This review compares the advantages and disadvantages of AS-OCT and UBM, and summarizes the most recent literature regarding the importance of these devices in glaucoma diagnosis and management. These devices not only aid in visualization of the angle, but also have important postsurgical applications in bleb and tube imaging.

Eye Care Quality and Accessibility Improvement in the Community (EQUALITY) for adults at risk for glaucoma: study rationale and design

Background

Primary open angle glaucoma is a chronic, progressive eye disease that is the leading cause of blindness among African Americans. Glaucoma progresses more rapidly and appears about 10 years earlier in African Americans as compared to whites. African Americans are also less likely to receive comprehensive eye care when glaucoma could be detected before irreversible blindness. Screening and follow-up protocols for managing glaucoma recommended by eye-care professional organizations are often not followed by primary eye-care providers, both ophthalmologists and optometrists. There is a pressing need to improve both the accessibility and quality of glaucoma care for African Americans. Telemedicine may be an effective solution for improving management and diagnosis of glaucoma because it depends on ocular imaging and tests that can be electronically transmitted to remote reading centers where tertiary care specialists can examine the results. We describe the Eye Care Quality and Accessibility Improvement in the Community project (EQUALITY), set to evaluate a teleglaucoma program deployed in retail-based primary eye care practices serving communities with a large percentage of African Americans.

Methods/Design

We conducted an observational, 1-year prospective study based in two Walmart Vision Centers in Alabama staffed by primary care optometrists. EQUALITY focuses on new or existing adult patients who are at-risk for glaucoma or already diagnosed with glaucoma. Patients receive dilated comprehensive examinations and diagnostic testing for glaucoma, followed by the optometrist’s diagnosis and a preliminary management plan. Results are transmitted to a glaucoma reading center where ophthalmologists who completed fellowship training in glaucoma review results and provide feedback to the optometrist, who manages the care of the patient. Patients also receive eye health education about glaucoma and comprehensive eye care. Research questions include diagnostic and management agreement between providers, the impact of eye health education on patients’ knowledge and adherence to follow-up and medication, patient satisfaction, program cost-effectiveness, and EQUALITY’s impact on Walmart pharmacy prescription rates.

Discussion

As eye-care delivery systems in the US strive to improve quality while reducing costs, telemedicine programs including teleglaucoma initiatives such as EQUALITY could contribute toward reaching this goal, particularly among underserved populations at-risk for chronic blinding diseases.

Use of health care claims data to study patients with ophthalmologic conditions

OBJECTIVE

To describe what information is or is not included in health care claims data, provide an overview of the main advantages and limitations of performing analyses using health care claims data, and offer general guidance on how to report and interpret findings of ophthalmology-related claims data analyses.

DESIGN

Systematic review.

PARTICIPANTS

Not applicable.

METHODS

A literature review and synthesis of methods for claims-based data analyses.

MAIN OUTCOME MEASURES

Not applicable.

RESULTS

Some advantages of using claims data for analyses include large, diverse sample sizes, longitudinal follow-up, lack of selection bias, and potential for complex, multivariable modeling. The disadvantages include (a) the inherent limitations of claims data, such as incomplete, inaccurate, or missing data, or the lack of specific billing codes for some conditions; and (b) the inability, in some circumstances, to adequately evaluate the appropriateness of care. In general, reports of claims data analyses should include clear descriptions of the following methodological elements: the data source, the inclusion and exclusion criteria, the specific billing codes used, and the potential confounding factors incorporated in the multivariable models.

CONCLUSIONS

The use of claims data for research is expected to increase with the enhanced availability of data from Medicare and other sources. The use of claims data to evaluate resource use and efficiency and to determine the basis for supplementary payment methods for physicians is anticipated. Thus, it will be increasingly important for eye care providers to use accurate and descriptive codes for billing. Adherence to general guidance on the reporting of claims data analyses, as outlined in this article, is important to enhance the credibility and applicability of findings. Guidance on optimal ways to conduct and report ophthalmology-related investigations using claims data will likely continue to evolve as health services researchers refine the metrics to analyze large administrative data sets.

Angle closure in Caucasians--a pilot, general ophthalmology clinic-based study

PURPOSE

To assess the rate of clinically significant angle closure in a predominantly Caucasian, clinic-based population, and consequently find out whether gonioscopy should be included in the routine ophthalmic examination.

METHODS

Patients aged ≥40 years with hyperopia ≥1 D were consecutively recruited in a community general ophthalmology clinic. Detailed darkroom gonioscopy was done, and primary angle closure was diagnosed if there was iridotrabecular apposition >180 degrees not secondary to an identifiable ocular disorder. Biometric parameters were measured and compared between the eyes with and without angle closure.

RESULTS

Eighty-four eyes from 84 patients (aged 61.3±8.9 y) were enrolled. There were 52 female (62%) and 32 male. Fourteen patients (16.7%) were diagnosed with angle closure. A statistically significant difference was observed between the eyes with and without angle closure in mean axial length (22.07±0.72 vs. 22.61±0.97, P=0.028), anterior chamber depth (ACD) (2.45±0.33 vs. 2.89±0.32, P<0.001), and lens thickness (4.97±0.3 vs. 4.62±0.4, P=0.002). Degree of hyperopia was marginally significant (3.13±2.3 vs. 2.45±1.5, P=0.09). In a logistic regression model, only ACD remained statistically significantly different (P=0.016). We tested the ability of ACD to distinguish eyes with angle closure. The area under the receiver operating characteristic curve was 0.824; using a cutoff ACD value of 2.65 mm, sensitivity was 0.786 with a specificity of 0.812.

CONCLUSIONS

Clinically significant angle closure, mandating close follow-up or preventive procedures, may be more common in Caucasians than currently thought. We recommend that gonioscopy should be included in the routine ophthalmic examination of all adults with hyperopia.

Glaucoma and clinical characteristics in Vietnamese Americans

PURPOSE

To assess the proportions of glaucoma types and clinical characteristics in Vietnamese Americans in a single-center, retrospective study.

METHODS

Medical charts of Vietnamese-American patients who visited a single private practice in Northern California from 1998-2007 were reviewed. The main outcome measures included the distribution and characteristics of glaucoma types, and clinical parameters associated with the presence of various glaucomas.

RESULTS

Data from 2247 patients aged 18-98 years were reviewed. Glaucoma was determined for 305 patients (13.6%). Among this group, 54.8% had primary open-angle glaucoma (POAG), 26.9% had primary angle-closure glaucoma (PACG), 13.4% had mixed mechanism glaucoma (MMG), and 4.9% had secondary glaucoma. In the MMG group (41 patients), 27 patients who initially had open angles developed narrow angles and underwent laser peripheral iridotomy (LPI) with a mean follow up of 6.4 years from the time of iridotomy. The other 13 patients had glaucoma progression with open angles after LPI. One POAG patient had neovascular glaucoma due to retinal vein occlusion several years later. Compared to the PACG group, the MMG group had significantly lower baseline intraocular pressure (25.0 vs. 20.2 mmHg, p = 0.007) but with no difference in biometry.

CONCLUSIONS

POAG is the major type of glaucoma in this clinic-based Vietnamese population. However, Vietnamese appear to have a relatively higher proportion of PACG than Caucasians and those of African descent. It is recommended that gonioscopy be part of the regular eye check-up for adult Vietnamese patients.

A panel assessment of glaucoma management: modification of existing RAND-like methodology for consensus in ophthalmology. Part II: Results and interpretation

PURPOSE

To present the results of a panel consensus assessment of evaluation and therapy relating to primary open-angle glaucoma based on available evidence and expert opinion.

DESIGN

A panel consensus assessment of glaucoma diagnosis and therapy using a modified RAND-like appropriateness methodology.

METHODS

One hundred and forty-eight questions, most of which related to glaucoma therapy, were created by a core nonvoting executive committee based on common clinical questions. An evidence-based review of the literature pertaining to these questions was provided to 10 voting panelists. These panelists, who did not participate in either the creation of the questions or the conduct of the literature review, then were polled using a modified technique derived from existing methodology.

RESULTS

Consensus agreement or disagreement was reached for 55.4% and 74.3% of the polling statements before and after the panel meeting, respectively. This represents a consensus agreement or disagreement on a majority of polling statements both before and after a meeting of all panelists and the two co-chairs of the program. There was an increase in the proportion of statements where consensus agreement was reached after the panel meeting.

CONCLUSIONS

Given the paucity of high-quality evidence relating to many of the issues addressed in this assessment and the variability of practice patterns among ophthalmologists, consensus agreement or disagreement was reached for a high proportion of polling statements.

Eye-Related Medicare Costs for Patients with Age-Related Macular Degeneration from 1995 to 1999

OBJECTIVE

Age-related macular degeneration (AMD) is the leading cause of blindness and severe visual impairment among the elderly in the United States. This study aims to assess eye-related Medicare costs from 1995 to 1999 in patients with both nonneovascular and neovascular AMD as compared with controls, and to delineate whether variations exist across demographic and clinical subgroups in eye-related Medicare costs over 5 years.

DESIGN

Retrospective, observational, population-based analysis.

PARTICIPANTS

Five percent random sample of Medicare beneficiaries.

METHODS

Data were obtained from the 5% random sample of Medicare beneficiaries with diagnoses of nonneovascular and neovascular AMD. A control group was selected based on diagnoses of blepharitis, chronic conjunctivitis, or blepharoconjuctivitis and no diagnosis of AMD. Eye-related claims were totaled and compared for each group over the 5-year study period. Demographic and clinical factors potentially influencing eye-related costs were also examined.

MAIN OUTCOME MEASURES

Eye-related Medicare costs during the 5-year study period.

RESULTS

Median eye-related Medicare costs were estimated at $1607 for neovascular AMD patients, $832 for nonneovascular AMD patients, and $658 for controls. Cost differences across groups were significant based on univariate and multivariate analyses (P<0.001). In linear regression analysis, males and blacks had significantly lower eye-related Medicare costs than females and whites, respectively (P<0.001).

CONCLUSIONS

Age-related macular degeneration represented a significant economic burden to the U.S. health care system for a single ophthalmic disease entity based on Medicare reimbursed eye-related costs before the availability of photodynamic therapy and anti-vascular endothelial growth factor therapy. Given that direct eye-related costs associated with the treatment of neovascular AMD are estimated at $569 million annually before the availability of therapy for subfoveal lesions, effective therapeutic measures may be associated with substantial cost offsets.

Evaluation of Practice Patterns for the Care of Open-angle Glaucoma Compared with Claims Data

OBJECTIVE

To perform a chart review to measure the validity of large claims databases in estimating patient cooperation with eyedrop therapy and to assess physician adherence with guidelines for a preferred practice pattern (PPP) using a new metric.

DESIGN

Claims database analysis, chart review, and telephone survey.

PARTICIPANTS

From 10,260 persons who were recently prescribed a prostaglandin eyedrop for open-angle glaucoma (OAG), a sample of 300 charts (3650 visits) was selected for detailed abstraction.

METHODS

Database review of pharmacy refill, diagnostic testing, and visit information, with chart review of a sample of patients from the database and interviews with an overlapping sample of patients and physicians.

MAIN OUTCOME MEASURES

The individual patient medication possession ratio (MPR), an index estimating the proportion of time that patients have prescribed drug available for use, frequency of examination findings present in charts, and associations between MPR and physician adherence to a PPP.

RESULTS

Chart data confirm that the claims database accurately identified the specific glaucoma eyedrop prescribed, but often identified long-term OAG patients as being new to treatment. Physicians frequently used billing codes for OAG in patients with normal visual field tests. Physicians varied dramatically in their adherence to the PPP, performing intraocular pressure measurements, disc evaluations and imaging, and visual field tests on 90% of OAG patients, but carrying out gonioscopy, central corneal thickness measurement, and setting of target intraocular pressure (IOP) on half of patients.

CONCLUSIONS

Large claims databases permit conclusions regarding patient cooperation with glaucoma eyedrop therapy, but they should be used cautiously in imputing severity of disease and prior treatment history. Physician adherence to practice guidelines varied substantially; thus, scoring systems for physician behavior have promise in measuring outcome improvements related to better care.