The Role of Optical Coherence Tomography Angiography in Glaucoma

Glaucoma is the leading cause of irreversible vision loss and comprises a group of chronic optic neuropathies characterized by progressive retinal ganglion cell (RGC) loss. Various etiologies, including impaired blood supply to the optic nerve, have been implicated for glaucoma pathogenesis. Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality for visualizing the ophthalmic microvasculature. Using blood flow as an intrinsic contrast agent, it distinguishes blood vessels from the surrounding tissue. Vessel density (VD) is mainly used as a metric for quantifying the ophthalmic microvasculature. The key anatomic regions for OCTA in glaucoma are the optic nerve head area including the peripapillary region, and the macular region. Specifically, VD of the superficial peripapillary and superficial macular microvasculature is reduced in glaucoma patients compared to unaffected subjects, and VD correlates with functional deficits measured by visual field (VF). This renders OCTA similar in diagnostic capabilities compared to structural retinal nerve fiber layer (RNFL) thickness measurements, especially in early glaucoma. Furthermore, in cases where RNFL thickness measurements are limited due to artifact or floor effect, OCTA technology can be used to evaluate and monitor glaucoma, such as in eyes with high myopia and eyes with advanced glaucoma. However, the clinical utility of OCTA in glaucoma management is limited due to the prevalence of imaging artifacts. Overall, OCTA can play a complementary role in structural OCT imaging and VF testing to aid in the diagnosis and monitoring of glaucoma.

Comparison of Structural and Functional Features in Primary Angle Closure and Open Angle Glaucomas

PRCIS

Using a large data set, we showed structural and functional differences between primary angle closure glaucoma (PACG) and primary open angle glaucoma (POAG). Primary angle closure glaucoma has relative structural preservation and worse functional loss inferiorly.

PURPOSE

To identify structural and functional differences in PACG and POAG.

MATERIALS AND METHODS

In this large cross-sectional study, differences in structural and functional damage were assessed among patients with POAG and PACG with optical coherence tomography and reliable visual field testing.

RESULTS

In all, 283 patients with PACG and 4110 patients with POAG were included. Despite similar mean deviation on visual fields (mean [SD] -7.73 [7.92] vs. -7.53 [6.90] dB, P =0.72), patients with PACG had thicker global retinal nerve fiber layer (RNFL), smaller cup volume, smaller cup-to-disc ratio, and larger rim area than POAG (77 [20] vs. 71 [14] µm, 0.32 [0.28] vs. 0.40 [0.29] mm 3 , 0.6 [0.2] vs. 0.7 [0.1], 1.07 [0.40] vs. 0.89 [0.30] mm 2 , P <0.001 for all), while patients with POAG had more pronounced inferior RNFL thinning (82 [24] vs. 95 [35] µm, P <0.001). In a multivariable analysis, hyperopia [odds ratio (OR): 1.24, confidence interval (CI): 1.13-1.37], smaller cup-to-disc ratio (OR: 0.69, CI: 0.61-0.78), thicker inferior RNFL (OR: 1.15, CI: 1.06-1.26) and worse mean deviation (OR: 0.95, CI: 0.92-0.98) were associated with PACG. Functionally, POAG was associated with superior paracentral loss and PACG with inferior field loss. After adjusting for average RNFL thickness, PACG was associated with more diffuse loss than POAG (total deviation differences 1.26-3.2 dB).

CONCLUSIONS

Patients with PACG had less structural damage than patients with POAG despite similar degrees of functional loss. Regional differences in patterns of functional and structural loss between POAG and PACG may improve disease monitoring for these glaucoma subtypes.

Harvard Glaucoma Fairness: A Retinal Nerve Disease Dataset for Fairness Learning and Fair Identity Normalization

Fairness (also known as equity interchangeably) in machine learning is important for societal wellbeing, but limited public datasets hinder its progress. Currently, no dedicated public medical datasets with imaging data for fairness learning are available, though minority groups suffer from more health issues. To address this gap, we introduce Harvard Glaucoma Fairness (Harvard-GF), a retinal nerve disease dataset including 3,300 subjects with both 2D and 3D imaging data and balanced racial groups for glaucoma detection. Glaucoma is the leading cause of irreversible blindness globally with Blacks having doubled glaucoma prevalence than other races. We also propose a fair identity normalization (FIN) approach to equalize the feature importance between different identity groups. Our FIN approach is compared with various state-of-the-art fairness learning methods with superior performance in the racial, gender, and ethnicity fairness tasks with 2D and 3D imaging data, demonstrating the utilities of our dataset Harvard-GF for fairness learning. To facilitate fairness comparisons between different models, we propose an equity-scaled performance measure, which can be flexibly used to compare all kinds of performance metrics in the context of fairness. The dataset and code are publicly accessible via https://ophai.hms.harvard.edu/harvard-gf3300/.

Artifacts in OCT Retinal Nerve Fiber Layer Imaging in Patients with Boston Keratoprosthesis Type 1

PURPOSE

To determine the clinical utility of OCT retinal nerve fiber layer (OCT RNFL) imaging for glaucoma evaluation in patients with Boston keratoprosthesis type 1 (KPro) by investigating imaging artifacts.

DESIGN

Case-control study.

SUBJECTS

Patients with KPro and without KPro (controls) matched for age, gender, and glaucoma diagnosis.

METHODS

The most recent Cirrus OCT RNFL scan from 1 eye was categorized as having good signal strength (SS; ≥ 6 out of 10) or poor SS (< 6). Those with good SS were analyzed by 2 independent reviewers for artifacts. Images with good SS and no artifacts affecting the scanning circle were considered useful for glaucoma evaluation.

MAIN OUTCOME MEASURES

The incidence of poor SS and artifacts in OCT RNFL images; patient characteristics associated with useful scans.

RESULTS

Sixty-five patients with KPro and 75 controls were included; 89.2% of KPro patients and 89.3% of control subjects had glaucoma (P = 0.98). Forty percent of KPro patients and 5.3% of controls had poor SS (P < 0.001). The proportion of images with either poor SS or artifacts was similar in KPro (76.9%) vs. controls (72.0%, P = 0.51). The most common artifacts in both groups were missing data (43.6%, 53.2%, respectively, P = 0.32) and motion artifact (25.6%, 19.7%, respectively, P = 0.47). Images were useful for glaucoma evaluation in 43.1% of KPro patients and in 69.3% of controls (P = 0.002). In the KPro group, patients with useful OCT scans, compared with those without, had better visual acuity (0.4 ± 0.3 vs. 0.9 ± 0.7 logarithm of the minimum angle of resolution, P = 0.004), and did not have congenital corneal pathologies (0.0% vs. 24.3%, P = 0.008). A multivariate analysis showed that KPro patients with older age had higher odds of useful OCT images (odds ratio, 1.05; P = 0.03). Among KPro patients with useful OCT scans, retinal nerve fiber layer thickness correlated with observed cup-to-disc ratio (Pearson correlation: r = -0.42, P = 0.03).

CONCLUSIONS

The rate of OCT RNFL images with either poor signal strength or artifacts in the KPro and control population was comparable. In patients with KPro, where intraocular pressure measurements are difficult and glaucoma is highly prevalent and often severe, OCT RNFL imaging can be useful for glaucoma evaluation.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Artifact Correction in Retinal Nerve Fiber Layer Thickness Maps Using Deep Learning and Its Clinical Utility in Glaucoma

Purpose

Correcting retinal nerve fiber layer thickness (RNFLT) artifacts in glaucoma with deep learning and evaluate its clinical usefulness.

Methods

We included 24,257 patients with optical coherence tomography and reliable visual field (VF) measurements within 30 days and 3,233 patients with reliable VF series of at least five measurements over ≥4 years. The artifacts are defined as RNFLT less than the known floor value of 50 µm. We selected 27,319 high-quality RNFLT maps with an artifact ratio (AR) of <2% as the ground truth. We created pseudo-artifacts from 21,722 low-quality RNFLT maps with AR of >5% and superimposed them on high-quality RNFLT maps to predict the artifact-free ground truth. We evaluated the impact of artifact correction on the structure-function relationship and progression forecasting.

Results

The mean absolute error and Pearson correlation of the artifact correction were 9.89 µm and 0.90 (P < 0.001), respectively. Artifact correction improved R2 for VF prediction in RNFLT maps with AR of >10% and AR of >20% up to 0.03 and 0.04 (P < 0.001), respectively. Artifact correction improved (P < 0.05) the AUC for progression prediction in RNFLT maps with AR of ≤10%, >10%, and >20%: (1) total deviation pointwise progression: 0.68 to 0.69, 0.62 to 0.63, and 0.62 to 0.64; and (2) mean deviation fast progression: 0.67 to 0.68, 0.54 to 0.60, and 0.45 to 0.56.

Conclusions

Artifact correction for RNFLTs improves VF and progression prediction in glaucoma.

Translational Relevance

Our model improves clinical usability of RNFLT maps with artifacts.

Steroid Response Following Dropless Cataract Surgery Using Subconjunctival Triamcinolone

Purpose

To assess the rates of postoperative steroid response following dropless cataract surgery using a subconjunctival depot of triamcinolone versus conventional cataract surgery using topical prednisolone.

Patients and Methods

We reviewed consecutive cataract surgery cases performed by a single surgeon to determine the likelihood of steroid response, defined as intraocular pressure (IOP) 50% above baseline or IOP > 24 mmHg postoperatively, excluding the first 72 hours. Logistic regression models were performed including baseline characteristics as exposures in the model and steroid response as the outcome. Main outcome measures were the proportion of eyes developing steroid response, risk factors for developing steroid response, and duration of steroid response.

Results

Of the 150 dropless and 218 conventional cases, 26 eyes developed steroid response (15 dropless and 11 conventional cases [10% vs 5%, P=0.096]). Risk factors for steroid response included dropless surgery (OR=2.43, 95% CI=1.03-6.02], P=0.046) and prior diagnosis of glaucoma (OR=7.18, 95% CI=2.66-19.22], P<0.001). Baseline IOP, age, sex, race, and axial length did not increase risk for steroid response. Of the eyes with steroid response, more dropless cases had an IOP elevation ≥30 days (9/15 eyes vs 1/11 eyes; P=0.008), including one patient with refractory IOP elevation in the dropless group who required urgent bilateral trabeculectomy for IOP control.

Conclusion

Dropless cataract surgery increases the risk of prolonged steroid response postoperatively. Patients with glaucoma have an increased risk of steroid response and may not be good candidates for dropless cataract surgery with subconjunctival triamcinolone.

Artifact-Tolerant Clustering-Guided Contrastive Embedding Learning for Ophthalmic Images in Glaucoma

Ophthalmic images, along with their derivatives like retinal nerve fiber layer (RNFL) thickness maps, play a crucial role in detecting and monitoring eye diseases such as glaucoma. For computer-aided diagnosis of eye diseases, the key technique is to automatically extract meaningful features from ophthalmic images that can reveal the biomarkers (e.g., RNFL thinning patterns) associated with functional vision loss. However, representation learning from ophthalmic images that links structural retinal damage with human vision loss is non-trivial mostly due to large anatomical variations between patients. This challenge is further amplified by the presence of image artifacts, commonly resulting from image acquisition and automated segmentation issues. In this paper, we present an artifact-tolerant unsupervised learning framework called EyeLearn for learning ophthalmic image representations in glaucoma cases. EyeLearn includes an artifact correction module to learn representations that optimally predict artifact-free images. In addition, EyeLearn adopts a clustering-guided contrastive learning strategy to explicitly capture the affinities within and between images. During training, images are dynamically organized into clusters to form contrastive samples, which encourage learning similar or dissimilar representations for images in the same or different clusters, respectively. To evaluate EyeLearn, we use the learned representations for visual field prediction and glaucoma detection with a real-world dataset of glaucoma patient ophthalmic images. Extensive experiments and comparisons with state-of-the-art methods confirm the effectiveness of EyeLearn in learning optimal feature representations from ophthalmic images.

Association between HSP-Specific T-Cell Counts and Retinal Nerve Fiber Layer Thickness in Patients with Primary Open-Angle Glaucoma

Objective

Previous laboratory reports implicate heat shock protein (HSP)-specific T-cell responses in glaucoma pathogenesis; here, we aimed to provide direct clinical evidence by correlating systemic HSP-specific T-cell levels with glaucoma severity in patients with primary open-angle glaucoma (POAG).

Design

Cross-sectional case-control study.

Subjects

Thirty-two adult patients with POAG and 38 controls underwent blood draw and optic nerve imaging.

Methods

Peripheral blood monocytes (PBMC) were stimulated in culture with HSP27, α-crystallin, a member of the small HSP family, or HSP60. Both interferon-γ (IFN-γ)+ CD4+ T helper type 1 cells (Th1) and transforming growth factor-β1 (TGF-β1)+ CD4+ regulatory T cells (Treg) were quantified by flow cytometry and presented as a percentage of total PBMC counts. Relevant cytokines were measured using enzyme-linked immunosorbent assays. Retinal nerve fiber layer thickness (RNFLT) was measured with OCT. Pearson's correlation (r) was used to assess correlations.

Main Outcome Measures

Correlations of HSP-specific T-cell counts, and serum levels of corresponding cytokine levels with RNFLT.

Results

Patients with POAG (visual field mean deviation, -4.7 ± 4.0 dB) and controls were similar in age, gender, and body mass index. Moreover, 46.9% of POAG and 60.0% of control subjects had prior cataract surgery (P = 0.48). Although no significant difference in total nonstimulated CD4+ Th1 or Treg cells was detected, patients with POAG exhibited significantly higher frequencies of Th1 cells specific for HSP27, α-crystallin, or HSP60 than controls (7.3 ± 7.9% vs. 2.6 ± 2.0%, P = 0.004; 5.8 ± 2.7% vs. 1.8 ± 1.3%, P < 0.001; 13.2 ± 13.3 vs. 4.3 ± 5.2, P = 0.01; respectively), but similar Treg specific for the same HSPs compared with controls (P ≥ 0.10 for all). Concordantly, the serum levels of IFN-γ were higher in POAG than in controls (36.2 ± 12.1 pg/ml vs. 10.0 ± 4.3 pg/ml; P < 0.001), but TGF-β1 levels did not differ. Average RNFLT of both eyes negatively correlated with HSP27- and α-crystallin-specific Th1 cell counts, and IFN-γ levels in all subjects after adjusting for age (partial correlation coefficient r = -0.31, P = 0.03; r = -0.52, p = 0.002; r = -0.72, P < 0.001, respectively).

Conclusions

Higher levels of HSP-specific Th1 cells are associated with thinner RNFLT in patients with POAG and control subjects. The significant inverse relationship between systemic HSP-specific Th1 cell count and RNFLT supports the role of these T cells in glaucomatous neurodegeneration.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Incidence and risk factors for glaucoma development and progression after corneal transplantation

OBJECTIVE

To assess the cumulative incidence and risk factors for glaucoma development and progression within 1-2 years following corneal transplant surgery.

DESIGN

Retrospective cohort study.

METHODS

Patients undergoing penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), Descemet stripping endothelial keratoplasty (DSEK), Descemet membrane endothelial keratoplasty (DMEK), Boston keratoprosthesis type I (KPro) implantation, or endothelial keratoplasty (DSEK or DMEK) under previous PK (EK under previous PK) at one academic institution with at least 1 year of follow-up were included. Primary outcome measures were cumulative incidence of glaucoma development and progression after corneal transplant, in patients without and with preoperative glaucoma, respectively. Risk factors for glaucoma development and progression were also assessed.

RESULTS

Four hundred and thirty-one eyes of 431 patients undergoing PK (113), DALK (17), DSEK (71), DMEK (168), KPro (35) and EK under previous PK (27) with a mean follow-up of 22.9 months were analyzed. The 1-year cumulative incidence for glaucoma development and progression was 28.0% and 17.8% in patients without and with preoperative glaucoma, respectively. In a Cox proportional hazards analysis, DSEK surgery, KPro implantation, average intraocular pressure (IOP) through follow-up and postoperative IOP spikes of ≥30 mmHg were each independently associated with glaucoma development or progression (p < 0.04 for all).

CONCLUSIONS

A significant proportion of patients developed glaucoma or exhibited glaucoma progression within 1 year after corneal transplantation. Patient selection for DSEK may partly explain the higher risk for glaucoma in these patients. Postoperative IOP spikes should be minimized and may indicate the need for co-management with a glaucoma specialist.

Combined Model of OCT Angiography and Structural OCT Parameters to Predict Paracentral Visual Field Loss in Primary Open-Angle Glaucoma

PURPOSE

To assess a model combining OCT angiography (OCTA) and OCT parameters to predict the severity of paracentral visual field (VF) loss in primary open-angle glaucoma (POAG).

DESIGN

Cross-sectional study.

PARTICIPANTS

Forty-four patients with POAG and 42 control subjects underwent OCTA and OCT imaging with a swept-source OCT device.

METHODS

The circumpapillary microvasculature was quantified for vessel density (cpVD) and flow (cpFlow) after delineation of Bruch's membrane opening and removal of large vessels. Retinal nerve fiber layer thickness (RNFLT) and Bruch's membrane opening-minimum rim width (BMO-MRW) were measured from structural OCT. Paracentral total deviation (PaTD) was defined as the average of the total deviation values within the central 10 degrees on Humphrey VF testing (24-2) for upper and lower hemifields. The OCT and OCTA parameters were measured in the affected hemisphere corresponding to the hemifield with lower PaTD for POAG patients. Models were created to predict affected PaTD based on RNFLT alone; RNFLT and BMO-MRW; OCTA alone; or RNFLT, BMO-MRW and OCTA parameters. The models were compared using coefficient of determination (r2) and Bayesian information criterion (BIC) score. Bayesian information criterion decrease of ≥6 indicates strong evidence for model improvement.

MAIN OUTCOME MEASURES

Performance of models containing OCT and OCTA parameters in predicting PaTD.

RESULTS

Patients with POAG and controls were similar in age and sex (65.9 ± 9.5 years and 38.4% male overall, P ≥ 0.56 for both). Average RNFLT, minimum RNFLT, average BMO-MRW, minimum BMO-MRW, cpVD, and cpFlow were all significantly lower (all P < 0.001) in the affected hemisphere in patients with POAG than in controls. In patients with POAG, the average mean deviation was -4.33 ± 3.25 dB; the PaTD of the affected hemifield averaged -4.55 ± 5.26 dB and correlated significantly with both OCTA and structural OCT parameters (r ≥ 0.43, P ≤ 0.004 for all). The model containing RNFLT, BMO-MRW, and OCTA parameters was superior in predicting affected PaTD (r2 = 0.47, BIC = 290.7), with higher r2 and lower BIC compared with all 3 other models.

CONCLUSIONS

A combined model of OCTA and structural OCT parameters can predict the severity of paracentral VF loss of the affected hemifield, supporting clinical utility of OCTA in patients with POAG with paracentral VF loss.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Transscleral vs endoscopic cyclophotocoagulation: safety and efficacy when combined with phacoemulsification

PURPOSE

To compare the effectiveness and safety of phacoemulsification combined with endoscopic cyclophotocoagulation (phaco/ECP), phacoemulsification combined with MicroPulse transscleral cyclophotocoagulation (phaco/MP-TSCPC), and phacoemulsification alone (phaco) in the treatment of coexisting cataract and glaucoma.

METHODS

Retrospective cohort study of consecutive cases at Massachusetts Eye & Ear. The main outcome measures were the cumulative probabilities of failure between the phaco/ECP group, phaco/MP-TSCPC group, and the phaco alone group with failure defined as reaching NLP vision at any point postoperatively, undergoing additional glaucoma surgery, or the inability to maintain ≥ 20% IOP reduction from baseline with IOP between 5-18 mmHg while maintaining ≤ baseline medications. Additional outcome measures included changes in average IOP, number of glaucoma medications, and complication rates.

RESULTS

Sixty-four eyes from 64 patients (25 phaco/ECP, 20 phaco/MPTSCPC, 19 phaco alone) were included in this study. The groups did not differ in age (mean 71.04 ± 6.7 years) or length of follow-up time. Baseline IOPs were significantly different between groups (15.78 ± 4.7 mmHg phaco/ECP, 18.37 ± 4.6 mmHg phaco/MP-TSCPC, 14.30 ± 4.2 mmHg phaco alone, p = 0.02). Primary open-angle glaucoma was the most common type of glaucoma in the phaco alone (42%) and phaco/ECP (48%) groups while mixed-mechanism glaucoma was the most common type in the phaco/MP-TSCPC group (40%). Surgical failure was less likely in eyes in the phaco/MP-TSCPC (3.40 times, p = 0.005) and phaco/ECP (1.40 times, p = 0.044) groups compared to phaco alone based on the Kaplan-Meier survival criteria. These differences maintained statistical significance when differences in preoperative IOP were taken into account using the Cox PH model (p = 0.011 and p = 0.004, respectively). Additionally, surgical failure was 1.98 times less likely following phaco/MP-TSCPC compared to phaco/ECP (p = 0.038). This difference only approached significance once differences in preoperative IOP were accounted for (p = 0.052). There was no significant difference in IOP reduction at 1 year between groups. Mean IOP reductions at 1 year were 3.07 ± 5.3 mmHg from a baseline of 15.78 ± 4.7 in the phaco/ECP group, 6.0 ± 4.3 mmHg from a baseline of 18.37 ± 4.6 in the phaco/MP-TSCPC group and 1.0 ± 1.6 from a baseline of 14.30 ± 4.2 mmHg in the phaco alone group. There were no differences in complication rates among the three groups.

CONCLUSIONS

Both Phaco/MP-TSCPC and phaco/ECP appear to provide superior efficacy for IOP control when compared to phaco alone. All three procedures had similar safety profiles.

Racial Disparities Affecting Black Patients in Glaucoma Diagnosis and Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Racial Disparities Affecting Black Patients In Glaucoma Diagnosis And Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Assessing Surface Shapes of the Optic Nerve Head and Peripapillary Retinal Nerve Fiber Layer in Glaucoma with Artificial Intelligence

Purpose

To assess 3-dimensional surface shape patterns of the optic nerve head (ONH) and peripapillary retinal nerve fiber layer (RNFL) in glaucoma with unsupervised artificial intelligence (AI).

Design

Retrospective study.

Participants

Patients with OCT scans obtained between 2016 and 2020 from Massachusetts Eye and Ear.

Methods

The first reliable Cirrus (Carl Zeiss Meditec, Inc) ONH OCT scans from each eye were selected. The ONH and RNFL surface shape was represented by the vertical positions of the inner limiting membrane (ILM) relative to the lowest ILM vertical position in each eye. Nonnegative matrix factorization was applied to determine the ONH and RNFL surface shape patterns, which then were correlated with OCT and visual field (VF) loss parameters and subsequent VF loss rate. We tested whether using ONH and RNFL surface shape patterns improved the prediction accuracy for associated VF loss and subsequent VF loss rates measured by adjusted r² and Bayesian information criterion (BIC) difference compared with using established OCT parameters alone.

Main Outcome Measures

Optic nerve head and RNFL surface shape patterns and prediction of the associated VF loss and subsequent VF loss rates.

Results

We determined 14 ONH and RNFL surface shape patterns using 9854 OCT scans from 5912 participants. Worse mean deviation (MD) was most correlated (r = 0.29 and r = 0.24, Pearson correlation; each P < 0.001) with lower coefficients of patterns 10 and 12 representing inferior and superior para-ONH nerve thinning, respectively. Worse MD was associated most with higher coefficients of patterns 5, 4, and 9 (r = –0.16, r = –0.13, and r = –0.13, respectively), representing higher peripheral ONH and RNFL surfaces. In addition to established ONH summary parameters and 12–clock-hour RNFL thickness, using ONH and RNFL surface patterns improved (BIC decrease: 182, 144, and 101, respectively; BIC decrease ≥ 6; strong model improvement) the prediction of accompanied MD (r² from 0.32 to 0.37), superior (r² from 0.27 to 0.31), and inferior (r² from 0.17 to 0.21) paracentral loss and improved (BIC decrease: 8 and 8, respectively) the prediction of subsequent VF MD loss rates (r² from 0 to 0.13) and inferior paracentral loss rates (r² from 0 to 0.16).

Conclusions

The ONH and RNFL surface shape patterns quantified by unsupervised AI techniques improved the structure–function relationship and subsequent VF loss rate prediction.

Restoration of Vision in Severe, Cicatricial, Ocular Surface Disease with the Boston Keratoprosthesis Type II

PURPOSE

To assess clinical outcomes of patients with severe, cicatricial ocular surface disease (OSD) implanted with the currently marketed design of the Boston keratoprosthesis type II (BK2).

DESIGN

Retrospective cohort study.

METHODS

Records of consecutive patients undergoing BK2 implantation from June 2009 to March 2021 were assessed for postoperative visual acuity, postoperative complications, device replacement, and additional surgeries.

RESULTS

Fifty-six eyes of 53 patients with a mean follow-up of 45.8 months (range: 0.2-134.7 months) were included. Stevens-Johnson syndrome/toxic epidermal necrolysis was the most common indication (49.1%), followed by mucous membrane pemphigoid (39.6%) and other OSD (11.3%). Visual acuity improved from LogMAR 2.2±0.5 preoperatively to 1.5±1.2 at final follow-up. Fifty of 56 eyes saw ≥20/200 at some point postoperatively. Of the eyes with a follow-up of more than 5 years, 50.0% retained a visual acuity of ≥20/200 at their final follow-up. The most common complications, over the entire postoperative course (mean ∼4 years), were de-novo or worsening glaucoma (41.1%), choroidal effusions (30.3%), retinal detachment (25.0%) and end-stage glaucoma (25.0%). In a univariate analysis, patients who experienced irreversible loss of ≥20/200 visual acuity were more likely to have been previously implanted with an older design of BK2, less likely to be on preoperative systemic immunosuppressive therapy, and less likely to have undergone concurrent glaucoma tube implantation, compared to patients who retained ≥20/200 acuity (p<0.04 for all).

CONCLUSIONS

Advances in device design and postoperative care have made implantation of BK2 a viable option for corneal blindness in the setting of severe cicatricial OSD.

The Prevalence of Autoimmune Diseases in Patients with Primary Open-Angle Glaucoma Undergoing Ophthalmic Surgeries

PURPOSE

To assess the prevalence of autoimmune disease (AiD) in patients with primary open-angle glaucoma (POAG) undergoing ophthalmic surgery.

DESIGN

Retrospective, cross-sectional study.

PARTICIPANTS

Patients with POAG undergoing any ophthalmic surgery and control subjects undergoing cataract surgery at the Massachusetts Eye and Ear from March 2019 to April 2020.

METHODS

All available medical records with patient demographics, ocular, and medical conditions were reviewed. Differences in AiD prevalence were assessed and adjusted for covariates using multiple logistic regression. Additionally, a subgroup analysis comparing the POAG patients with and without AiD was performed.

MAIN OUTCOME MEASURES

To assess the prevalence of AiD based on the American Autoimmune Related Diseases Association list.

RESULTS

A total of 172 patients with POAG and 179 controls were included. The overall prevalence of AiD was 17.4% in the POAG group and 10.1% in the controls (P = 0.044); 6.4% of POAG patients and 3.4% of controls had more than 1 AiD (P = 0.18). The most prevalent AiDs in POAG group were rheumatoid arthritis (4.6%) and psoriasis (4.1%), which were also the most common in controls (2.8% each). In a fully adjusted multiple logistic regression analysis accounting for steroid use, having an AiD was associated with 2.62-fold increased odds of POAG relative to controls (95% confidence interval, 1.27-5.36, P = 0.009); other risk factors for POAG derived from the analysis included age (odds ratio [OR], 1.04, P = 0.006), diabetes mellitus (OR, 2.31, P = 0.008), and non-White ethnicity (OR, 4.75, P < 0.001). In a case-only analysis involving the eye with worse glaucoma, there was no statistical difference in visual field mean deviation or retinal nerve fiber layer (RNFL) thickness in POAG patients with AiD (n = 30) and without AiD (n = 142, P > 0.13, for both).

CONCLUSIONS

A higher prevalence of AiD was found in POAG patients compared with control patients undergoing ophthalmic surgery. The presence of AiD was associated with increased risk for POAG after adjusting for covariates. Additional factors may have prevented a difference in RNFL thickness in POAG patients with and without AiD. Autoimmunity should be explored further in the pathogenesis of POAG.

Predicting Global Test-Retest Variability of Visual Fields in Glaucoma

PURPOSE

To model the global test-retest variability of visual fields (VFs) in glaucoma.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Test-retest VFs from 4044 eyes of 4044 participants.

METHODS

We selected 2 reliable VFs per eye measured with the Humphrey Field Analyzer (Swedish interactive threshold algorithm 24-2) within 30 days of each other. Each VF had fixation losses (FLs) of 33% or less, false-negative results (FNRs) of 20% or less, and false-positive results (FPRs) of 20% or less. Stepwise linear regression was applied to select the model best predicting the global test-retest variability from 3 categories of features of the first VF: (1) base parameters (age, mean deviation, pattern standard deviation, glaucoma hemifield test results, FPR, FNR, and FL); (2) total deviation (TD) at each location; and (3) computationally derived archetype VF loss patterns. The global test-retest variability was defined as root mean square deviation (RMSD) of TD values at all 52 VF locations.

MAIN OUTCOME MEASURES

Archetype models to predict the global test-retest variability.

RESULTS

The mean ± standard deviation of the root mean square deviation was 4.39 ± 2.55 dB. Between the 2 VF tests, TD values were correlated more strongly in central than in peripheral VF locations (intraclass coefficient, 0.66-0.89; P < 0.001). Compared with the model using base parameters alone (adjusted R2 = 0.45), adding TD values improved prediction accuracy of the global variability (adjusted R2 = 0.53; P < 0.001; Bayesian information criterion [BIC] decrease of 527; change of >6 represents strong improvement). Lower TD sensitivity in the outermost peripheral VF locations was predictive of higher global variability. Adding archetypes to the base model improved model performance with an adjusted R2 of 0.53 (P < 0.001) and lowering of BIC by 583. Greater variability was associated with concentric peripheral defect, temporal hemianopia, inferotemporal defect, near total loss, superior peripheral defect, and central scotoma (listed in order of decreasing statistical significance), and less normal VF results and superior paracentral defect.

CONCLUSIONS

Inclusion of archetype VF loss patterns and TD values based on first VF improved the prediction of the global test-retest variability than using traditional global VF indices alone.

Development and Comparison of Machine Learning Algorithms to Determine Visual Field Progression

Purpose

To develop and test machine learning classifiers (MLCs) for determining visual field progression.

Methods

In total, 90,713 visual fields from 13,156 eyes were included. Six different progression algorithms (linear regression of mean deviation, linear regression of the visual field index, Advanced Glaucoma Intervention Study algorithm, Collaborative Initial Glaucoma Treatment Study algorithm, pointwise linear regression [PLR], and permutation of PLR) were applied to classify each eye as progressing or stable. Six MLCs were applied (logistic regression, random forest, extreme gradient boosting, support vector classifier, convolutional neural network, fully connected neural network) using a training and testing set. For MLC input, visual fields for a given eye were divided into the first and second half and each location averaged over time within each half. Each algorithm was tested for accuracy, sensitivity, positive predictive value, and class bias with a subset of visual fields labeled by a panel of three experts from 161 eyes.

Results

MLCs had similar performance metrics as some of the conventional algorithms and ranged from 87% to 91% accurate with sensitivity ranging from 0.83 to 0.88 and specificity from 0.92 to 0.96. All conventional algorithms showed significant class bias, meaning each individual algorithm was more likely to grade uncertain cases as either progressing or stable (P ≤ 0.01). Conversely, all MLCs were balanced, meaning they were equally likely to grade uncertain cases as either progressing or stable (P ≥ 0.08).

Conclusions

MLCs showed a moderate to high level of accuracy, sensitivity, and specificity and were more balanced than conventional algorithms.

Translational Relevance

MLCs may help to determine visual field progression.

Paired Optic Nerve Microvasculature and Nailfold Capillary Measurements in Primary Open-Angle Glaucoma

Purpose

To assess microvascular beds in the optic nerve head (ONH), peripapillary tissue, and the nailfold in patients with primary open-angle glaucoma (POAG) versus controls.

Methods

Patients with POAG (n = 22) and controls (n = 12) underwent swept-source optical coherence tomography angiography of ophthalmic microvasculature and nailfold video capillaroscopy of the hand. The main outcomes were vessel density (VD) and blood flow of the ONH, the peripapillary and the nailfold microvasculatures.

Results

Patients with POAG were younger than controls (63.5 ± 9.4 vs. 69.9 ± 6.5 years, P = 0.03). Deep ONH VD and blood flow were lower in patients with POAG than controls (39.1% ± 3.5% vs. 43.8% ± 5.7%; 37.8% ± 5.3% vs. 46.0% ± 7.8%, respectively, P < 0.02 for both); similar results were observed with peripapillary VD (37.9 ± 2.6%, 43.4 ± 7.6%, respectively, P = 0.03). Nailfold capillary density and blood flow were lower in patients with POAG than controls (8.8 ± 1.0 vs. 9.8 ± 0.9 capillaries/mm; 19.9 ± 9.4 vs. 33.7 ± 9.8 pL/s, respectively; P < 0.009 for both). After adjusting for age and gender, deep ONH VD and blood flow, peripapillary VD, and nailfold capillary blood flow were lower in POAG than controls (β = −0.04, −0.07, −0.05, −13.19, respectively, P ≤ 0.046 for all). Among all participants, there were positive correlations between deep ONH and nailfold capillary blood flow (Pearson's correlation coefficient r = 0.42, P = 0.02), peripapillary and nailfold capillary density (r = 0.43, P = 0.03), and peripapillary and nailfold capillary blood flow (r = 0.49, P = 0.01).

Conclusions

Patients with POAG demonstrated morphologic and hemodynamic alterations in both ophthalmic and nailfold microvascular beds compared to controls.

Translational Relevance

The concomitant abnormalities in nailfold capillaries and relevant ocular vascular beds in POAG suggest that the microvasculature may be a target for POAG treatment.

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.

Inter-Eye Association of Visual Field Defects in Glaucoma and Its Clinical Utility

Purpose

To investigate intereye associations of visual field (VF) defects.

Methods

We selected 24-2 VF pairs of both eyes from 63,604 patients tested on the same date with mean deviation (MD) ≥ −12 dB. VFs were decomposed into one normal and 15 defect patterns previously identified using archetypal analysis. VF pattern weighting coefficients were correlated between the worse and better eyes, as defined by MD. VF defect patterns (weighting coefficients > 10%) in the better eye were predicted from weighting coefficients of the worse eye by logistic regression models, which were evaluated by area under the receiver operating characteristic curve (AUC).

Results

Intereye correlations of archetypal VF patterns were strongest for the same defect pattern between fellow eyes. The AUCs for predicting the presence of 15 defect patterns in the better eye based on the worse eye ranged from 0.69 (superior nasal step) to 0.92 (near total loss). The AUC for predicting superior paracentral loss was 0.89. Superior paracentral loss in the better eye was positively correlated with coefficients of superior paracentral loss, central scotoma, superior altitudinal defect, nasal hemianopia, and inferior paracentral loss in the worse eye, and negatively correlated with coefficients of the normal VF, superior peripheral defect, concentric peripheral defect, and temporal wedge. The parameters are presented in the descending order of statistical significance.

Conclusions

VF patterns of the worse eye are predictive of VF defects in the better eye.

Translational Relevance

Our models can potentially assist clinicians to better interpret VF loss under measurement uncertainty.

Characterization of Prelaminar Wedge-Shaped Defects in Primary Open-Angle Glaucoma

PURPOSE

To determine the clinical relevance of prelaminar wedge defects (PLWDs) detected by swept-source optical coherence tomography (SS-OCT) in primary open-angle glaucoma (POAG).

MATERIALS AND METHODS

In this retrospective case-control study, PLWDs were defined as triangular-shaped defects at the surface of the optic nerve prelaminar tissue, not adjacent to blood vessels, present on cross-sectional SS-OCT scans. Two observers masked to diagnosis independently reviewed scans to detect PLWDs and lamina cribrosa defects. History of disc hemorrhage, occurring within 2 years prior to imaging, was obtained from chart review. One eye per subject was randomly selected. Two-sided t-tests, analysis of variance with Bonferroni correction, and multivariable logistic regression analysis were performed to explore demographic and clinical features associated with PLWDs.

RESULTS

40 POAG and 23 control eyes were included. PLWDS were found in 27.5% of POAG (n = 11) and 4.3% of controls (n = 1, p = .04). Eyes with repeat SS-OCT imaging (7 POAG and 0 controls) had persistent PLWDs. More POAG eyes with PLWDs had a history of disc hemorrhage (45.5%) than POAG eyes without PLWDs (3.4%, p = .004). On multivariable analysis, compared to POAG without PLWDs, POAG with PLWDs had increased odds of observed disc hemorrhage (OR = 21.6, 95% CI, 2.2-589.0, p = .02) after adjusting for age, gender, visual field mean deviation and maximum intraocular pressure (IOP). POAG with PLWDs had more lamina cribrosa defects (45.5%) than POAG without PLWDs (3.4%, p = .01) but did not differ significantly from controls (8.7%, p = .07). Compared to all patients without PLWDs, patients with PLWDs had increased odds of having lamina cribrosa defects (OR = 44.8; 95% CI, 6.3-703.6, p < .001) after adjusting for age, gender, and maximum IOP.

CONCLUSIONS

PLWDs were more frequently found in POAG than control eyes and were associated with a history of disc hemorrhage and lamina cribrosa defects. PLWDs may be a useful imaging biomarker of glaucomatous damage.

Quantification of the Peripapillary Microvasculature in Eyes with Glaucomatous Paracentral Visual Field Loss

PURPOSE

To quantify abnormalities in the peripapillary microvasculature in eyes with primary open-angle glaucoma (POAG) and paracentral visual field (VF) loss.

DESIGN

Prospective, cross-sectional study.

PARTICIPANTS

Thirty-three POAG patients, including 15 with paracentral VF loss and 18 with peripheral VF loss, and 31 control participants underwent swept-source OCT angiography (OCTA) of the peripapillary region.

METHODS

The POAG groups were matched by VF mean deviation (MD). The peripapillary microvasculature from the internal limiting membrane to the retinal nerve fiber layer (RNFL) interface was quantified within a 0.70-mm annulus around Bruch's membrane opening after removal of large vessels. Both vessel density (VD) and the integrated OCTA by ratio analysis signal (IOS) suggestive of flow were measured. Regional VD and IOS were measured from the affected hemisphere corresponding to the VF hemifield of more severe loss, which was used to calculate the paracentral total deviation (PaTD), or total deviation within the central 10°. One eye per participant was included.

MAIN OUTCOME MEASURES

Difference in peripapillary OCTA measurements between paracentral and peripheral VF loss groups and correlation of peripapillary VD and IOS with PaTD.

RESULTS

The POAG groups had matched VF MD (-3.1 ± 2.5 dB paracentral vs. -2.3 ± 2.0 dB peripheral; P = 0.31), did not differ in average RNFL thickness (71.1 ± 14.7 μm vs. 78.1 ± 15.0 μm; P = 0.55), but differed in age (59.2 ± 9.6 years paracentral vs. 67.4 ± 6.6 years peripheral; P = 0.02). Compared with control participants, both paracentral and peripheral VF loss groups showed reduced VD (P < 0.001 and P = 0.009, respectively) and IOS (P < 0.001 and P = 0.01, respectively) in the affected hemisphere. Compared with POAG eyes with peripheral VF loss, the paracentral group showed reduced peripapillary VD (38.0 ± 2.0%, 35.0 ± 2.2%, respectively; P = 0.001) and IOS (44.3 ± 3.1%, 40.4 ± 4.0%, respectively; P = 0.02) in the affected hemisphere. Among all POAG eyes, peripapillary VD and IOS of the affected hemisphere correlated significantly with functional measurement of paracentral loss (PaTD, r = 0.40, P = 0.02; r = 0.45, P = 0.008; respectively). These correlations remained significant after adjusting for age (r = 0.41, P = 0.02; r = 0.47, P = 0.01; respectively).

CONCLUSIONS

Regional peripapillary microvasculature showed decreased VD and flow in POAG with paracentral loss, supporting its importance in this glaucoma subtype.

Densitometric Profiles of Optic Disc Hemorrhages in the Ocular Hypertension Treatment Study

PURPOSE

The origin of blood in glaucoma-related disc hemorrhages (DH) remains unknown. A prior clinic-based study of primary open-angle glaucoma (POAG)-related DH showed that they had grayscale pixel intensities more similar to blood from retinal macroaneurysms and adjacent retinal arterioles than to blood from retinal vein occlusions or adjacent retinal venules, suggesting an arterial source. Here we assessed the densitometric profile of DH from fundus photographs in the Ocular Hypertension Treatment Study (OHTS).

DESIGN

Retrospective cross-sectional study of prospectively collected images.

METHODS

Stereo disc photographs of 161 DH events from 83 OHTS participants (mean age [standard deviation (SD)]: 65.6 [9.2] years; 46.6% female; 13.0% black race) were imported into ImageJ to measure densitometry differences (adjacent arterioles minus DH [ΔA] or venules minus DH [ΔV]). Their size as percentage of disc area, ratio of length to midpoint width, and location relative to the disc margin were also analyzed. We performed t tests to compare ΔA and ΔV, analysis of variance to compare ΔA and ΔV across DH recurrent events, and multivariable linear regression to identify determinants of ΔA and ΔV.

RESULTS

Mean (SD) ΔA and ΔV were -2.2 (8.7) and -11.4 (9.7) pixel intensity units, respectively (P < .001). ΔA and ΔV each did not differ significantly across recurrence of DH (P ≥ .92) or between DH events with and without POAG (P ≥ .26).

CONCLUSIONS

OHTS DH had densitometric measurements more similar in magnitude to adjacent arterioles than venules, supporting an arterial origin for DH. Vascular dysregulation may contribute to disc hemorrhage formation in ocular hypertension.

An Artificial Intelligence Approach to Assess Spatial Patterns of Retinal Nerve Fiber Layer Thickness Maps in Glaucoma

Purpose

The purpose of this study was to classify the spatial patterns of retinal nerve fiber layer thickness (RNFLT) and assess their associations with visual field (VF) loss in glaucoma.

Methods

We used paired reliable 24-2 VFs and optical coherence tomography scans of 691 eyes from 691 patients. The RNFLT maps were used to determine the RNFLT patterns (RPs) by non-negative matrix factorization (NMF). The RPs were correlated with mean deviation (MD), spherical equivalent (SE), and major blood vessel locations. The RPs were further used to predict the 52 total deviation (TD) values by linear regression compared with models using 24 15-degree sectors. Last, we associated the RPs with average TDs of the central upper two locations (C2-TD). Stepwise regression was applied to remove redundant features.

Results

NMF highlighted 16 distinct RPs. Twelve RPs had arcuate-like informative zones (iZones): six with superior iZones, five with inferior iZones, and one RP with a bi-hemifield iZone, and four with non-arcuate-like temporal or nasal iZones. Twelve, nine, nine, and nine RPs were significantly (P < 0.05) correlated to MD, SE, and superior and inferior artery locations, respectively. Using RPs significantly (P < 0.05) improved the prediction of 52 TDs compared with using 24 15-degree sectors. Using RPs significantly (P < 0.001) improved the C2-TD prediction related to thinning in the inferior vulnerability zone compared with using the 24 sectoral RNFLTs.

Conclusions

Using RPs improved the VF prediction compared with using sectoral RNFLTs.

Translational Relevance

The RPs characterizing both pathological and anatomical variations can potentially assist clinicians better assess RNFLT loss.

Artificial Intelligence Classification of Central Visual Field Patterns in Glaucoma

PURPOSE

To quantify the central visual field (VF) loss patterns in glaucoma using artificial intelligence.

DESIGN

Retrospective study.

PARTICIPANTS

VFs of 8712 patients with 13 951 Humphrey 10-2 test results from 13 951 eyes for cross-sectional analyses, and 824 patients with at least 5 reliable 10-2 test results at 6-month intervals or more from 1191 eyes for longitudinal analyses.

METHODS

Total deviation values were used to determine the central VF patterns using the most recent 10-2 test results. A 24-2 VF within a 3-month window of the 10-2 tests was used to stage eyes into mild, moderate, or severe functional loss using the Hodapp-Anderson-Parrish scale at baseline. Archetypal analysis was applied to determine the central VF patterns. Cross-validation was performed to determine the optimal number of patterns. Stepwise regression was applied to select the optimal feature combination of global indices, average baseline decomposition coefficients from central VFs archetypes, and other factors to predict central VF mean deviation (MD) slope based on the Bayesian information criterion (BIC).

MAIN OUTCOME MEASURES

The central VF patterns stratified by severity stage based on 24-2 test results and a model to predict the central VF MD change over time using baseline test results.

RESULTS

From cross-sectional analysis, 17 distinct central VF patterns were determined for the 13 951 eyes across the spectrum of disease severity. These central VF patterns could be divided into isolated superior loss, isolated inferior loss, diffuse loss, and other loss patterns. Notably, 4 of the 5 patterns of diffuse VF loss preserved the less vulnerable inferotemporal zone, whereas they lost most of the remaining more vulnerable zone described by the Hood model. Inclusion of coefficients from central VF archetypical patterns strongly improved the prediction of central VF MD slope (BIC decrease, 35; BIC decrease of >6 indicating strong prediction improvement) than using only the global indices of 2 baseline VF results. Eyes with baseline VF results with more superonasal and inferonasal loss were more likely to show worsening MD over time.

CONCLUSIONS

We quantified central VF patterns in glaucoma, which were used to improve the prediction of central VF worsening compared with using only global indices.

Characterization of Central Visual Field Loss in End-stage Glaucoma by Unsupervised Artificial Intelligence

Importance

Although the central visual field (VF) in end-stage glaucoma may substantially vary among patients, structure-function studies and quality-of-life assessments are impeded by the lack of appropriate characterization of end-stage VF loss.

Objective

To provide a quantitative characterization and classification of central VF loss in end-stage glaucoma.

Design, Setting, and Participants

This retrospective cohort study collected data from 5 US glaucoma services from June 1, 1999, through October 1, 2014. A total of 2912 reliable 10-2 VFs of 1103 eyes from 1010 patients measured after end-stage 24-2 VFs with a mean deviation (MD) of -22 dB or less were included in the analysis. Data were analyzed from March 28, 2018, through May 23, 2019.

Main Outcomes and Measures

Central VF patterns were determined by an artificial intelligence algorithm termed archetypal analysis. Longitudinal analyses were performed to investigate whether the development of central VF defect mostly affects specific vulnerability zones.

Results

Among the 1103 patients with the most recent VFs, mean (SD) age was 70.4 (14.3) years; mean (SD) 10-2 MD, -21.5 (5.6) dB. Fourteen central VF patterns were determined, including the most common temporal sparing patterns (304 [27.5%]), followed by mostly nasal loss (280 [25.4%]), hemifield loss (169 [15.3%]), central island (120 [10.9%]), total loss (91 [8.3%]), nearly intact field (56 [5.1%]), inferonasal quadrant sparing (42 [3.8%]), and nearly total loss (41 [3.7%]). Location-specific median total deviation analyses partitioned the central VF into a more vulnerable superonasal zone and a less vulnerable inferotemporal zone. At 1-year and 2-year follow-up, new defects mostly occurred in the more vulnerable zone. Initial encroachments on an intact central VF at follow-up were more likely to be from nasal loss (11 [18.4%]; P < .001). One of the nasal loss patterns had a substantial chance at 2-year follow-up (8 [11.0%]; P = .004) to shift to total loss, whereas others did not.

Conclusions and Relevance

In this study, central VF loss in end-stage glaucoma was found to exhibit characteristic patterns that might be associated with different subtypes. Initial central VF loss is likely to be nasal loss, and 1 specific type of nasal loss is likely to develop into total loss.

An Artificial Intelligence Approach to Detect Visual Field Progression in Glaucoma Based on Spatial Pattern Analysis

Purpose

To detect visual field (VF) progression by analyzing spatial pattern changes.

Methods

We selected 12,217 eyes from 7360 patients with at least five reliable 24-2 VFs and 5 years of follow-up with an interval of at least 6 months. VFs were decomposed into 16 archetype patterns previously derived by artificial intelligence techniques. Linear regressions were applied to the 16 archetype weights of VF series over time. We defined progression as the decrease rate of the normal archetype or any increase rate of the 15 VF defect archetypes to be outside normal limits. The archetype method was compared with mean deviation (MD) slope, Advanced Glaucoma Intervention Study (AGIS) scoring, Collaborative Initial Glaucoma Treatment Study (CIGTS) scoring, and the permutation of pointwise linear regression (PoPLR), and was validated by a subset of VFs assessed by three glaucoma specialists.

Results

In the method development cohort of 11,817 eyes, the archetype method agreed more with MD slope (kappa: 0.37) and PoPLR (0.33) than AGIS (0.12) and CIGTS (0.22). The most frequently progressed patterns included decreased normal pattern (63.7%), and increased nasal steps (16.4%), altitudinal loss (15.9%), superior-peripheral defect (12.1%), paracentral/central defects (10.5%), and near total loss (10.4%). In the clinical validation cohort of 397 eyes with 27.5% of confirmed progression, the agreement (kappa) and accuracy (mean of hit rate and correct rejection rate) of the archetype method (0.51 and 0.77) significantly (P < 0.001 for all) outperformed AGIS (0.06 and 0.52), CIGTS (0.24 and 0.59), MD slope (0.21 and 0.59), and PoPLR (0.26 and 0.60).

Conclusions

The archetype method can inform clinicians of VF progression patterns.

A Review of OCT Angiography in Glaucoma

There is growing evidence that vascular dysfunction plays a role in the pathogenesis of glaucoma. The details of this relationship have remained elusive partially due to limitations in our ability to assess blood flow in the optic nerve. Optical coherence tomography angiography (OCTA) has emerged as a promising new technology well positioned to become the first clinically suitable test of optic nerve perfusion. OCTA uses the motion of red blood cells as an intrinsic contrast agent to create reproducible images of microvascular networks rapidly and non-invasively. A significant body of research regarding the use of OCTA in glaucoma has emerged in recent years. This review aims to provide an overview of the basic principles underlying OCTA technology, summarize the current literature regarding the application of OCTA in the management of glaucoma, and address the role of OCTA in explicating the vascular pathogenesis of glaucoma.

Agreement and Predictors of Discordance of 6 Visual Field Progression Algorithms

PURPOSE

To determine the agreement of 6 established visual field (VF) progression algorithms in a large dataset of VFs from multiple institutions and to determine predictors of discordance among these algorithms.

DESIGN

Retrospective longitudinal cohort study.

PARTICIPANTS

Visual fields from 5 major eye care institutions in the United States were analyzed, including a subset of eyes with at least 5 Swedish interactive threshold algorithm standard 24-2 VFs that met our reliability criteria. Of a total of 831 240 VFs, a subset of 90 713 VFs from 13 156 eyes of 8499 patients met the inclusion criteria.

METHODS

Six commonly used VF progression algorithms (mean deviation [MD] slope, VF index slope, Advanced Glaucoma Intervention Study, Collaborative Initial Glaucoma Treatment Study, pointwise linear regression, and permutation of pointwise linear regression) were applied to this cohort, and each eye was determined to be stable or progressing using each measure. Agreement between individual algorithms was tested using Cohen's κ coefficient. Bivariate and multivariate analyses were used to determine predictors of discordance (3 algorithms progressing and 3 algorithms stable).

MAIN OUTCOME MEASURES

Agreement and discordance between algorithms.

RESULTS

Individual algorithms showed poor to moderate agreement with each other when compared directly (κ range, 0.12-0.52). Based on at least 4 algorithms, 11.7% of eyes progressed. Major predictors of discordance or lack of agreement among algorithms were more depressed initial MD (P < 0.01) and older age at first available VF (P < 0.01). A greater number of VFs (P < 0.01), more years of follow-up (P < 0.01), and eye care institution (P = 0.03) also were associated with discordance.

CONCLUSIONS

This extremely large comparative series demonstrated that existing algorithms have limited agreement and that agreement varies with clinical parameters, including institution. These issues underscore the challenges to the clinical use and application of progression algorithms and of applying big-data results to individual practices.

Blood Levels of Tumor Necrosis Factor Alpha and Its Type 2 Receptor Are Elevated in Patients with Boston Type I Keratoprosthesis

Purpose: Boston keratoprosthesis (KPro) patients are prone to glaucoma even with well-controlled intraocular pressure (IOP). Recent experimental data have shown that soluble tumor necrosis factor alpha (TNF-α) after ocular injury may contribute to progressive retinal damage and subsequent glaucoma. This study evaluates the blood plasma levels of soluble TNF-α, TNF receptors 1 (TNFR1) and 2 (TNFR2), and leptin in patients with Boston type I KPro. Methods: Venous blood samples were collected from KPro patients with glaucoma (KPro G, n = 19), KPro patients without glaucoma (KPro NoG, n = 12), primary angle closure glaucoma without KPro (PACG, n = 13), and narrow angles without glaucoma or KPro (NA, n = 21). TNF-α, TNFR1, TNFR2, and leptin levels were quantified using the enzyme-linked immunosorbent assay. Erythrocyte sedimentation rate (ESR) was assessed using the Westergren test. Patients with underlying autoimmune conditions or diabetes were excluded from the study. Results: All groups had similar age, body mass index (BMI), IOP, and ESR (p ≥ 0.11). The mean time from KPro surgery to blood draw was 5.3 ± 3.7 years. Compared to NA patients (0.72 ± 0.3 pg/ml), KPro G and KPro NoG patients had higher blood plasma levels of TNF-α (1.18 ± 0.58 pg/ml, p = 0.006; 1.16 ± 0.50 pg/ml, p = 0.04, respectively). Similarly, KPro G patients had higher blood plasma levels of TNFR2 (2768 ± 1368 pg/ml) than NA patients (2020 ± 435 pg/ml, p = 0.048). In multivariate analysis, KPro status remained positively associated with TNF-α levels (β = 0.36; 95% confidence intervals [CI]: 0.14-0.58; p = 0.002) and TNFR2 levels (β = 458.3; 95% CI: 32.8-883.7; p = 0.035) after adjusting for age, gender, BMI, glaucoma status, and ESR. TNFR1 and leptin levels were not significantly different in the study groups. Conclusions: We detected elevated serum levels of TNF-α and TNFR2 in KPro patients. Longitudinal studies are needed to establish TNF-α and TNFR2 as serum biomarkers related to KPro surgery. Abbreviations: BCVA: best corrected visual acuity; BMI: body mass index; CDR: cup-to-disc ratio; EDTA: ethylenediaminetetraacetic acid; ELISA: enzyme-linked immunosorbent assay; ESR: erythrocyte sedimentation rate; HVF: Humphrey visual field; IOP: intraocular pressure; KPro G: keratoprosthesis with glaucoma; KPro NoG: keratoprosthesis without glaucoma; KPro: keratoprosthesis; MD: mean deviation; NA: narrow angle; non-KPro: without keratoprosthesis; PACG: primary angle closure glaucoma; RNFL: retinal nerve fiber layer; TNF-α: tumor necrosis factor alpha; TNFR1: tumor necrosis factor receptor 1; TNFR2: tumor necrosis factor receptor 2.

Shear-band affected zone revealed by magnetic domains in a ferromagnetic metallic glass

Plastic deformation of metallic glasses (MGs) has long been considered to be confined to nanoscale shear bands, but recently an affected zone around the shear band was found. Yet, due to technical limitations, the shear-band affected zone (SBAZ), which is critical for understanding shear banding and design of ductile MGs, has yet to be precisely identified. Here, by using magnetic domains as a probe with sufficiently high sensitivity and spatial resolution, we unveil the structure of SBAZs in detail. We demonstrate that shear banding is accompanied by a micrometer-scale SBAZ with a gradient in the strain field, and multiple shear bands interact through the superimposition of SBAZs. There also exists an ultra-long-range gradual elastic stress field extending hundreds of micrometers away from the shear band. Our findings provide a comprehensive picture on shear banding and are important for elucidating the micro-mechanisms of plastic deformation in glasses.

Metallic glasses deform along nanoscale shear bands, and while it is known that they affect the neighboring glass regions, exactly how is unclear. Here, the authors use magnetic force microscopy to atomically resolve the shear-band affected zone and show its effects extends much further than previously thought.

Resting nailfold capillary blood flow in primary open-angle glaucoma

Background/Aims

An altered haemodynamic profile for various ocular posterior segment capillary beds has been documented in primary open-angle glaucoma (POAG). POAG may also involve abnormal non-ocular blood flow, and the nailfold capillaries, which are not affected by elevated intraocular pressure (IOP), are readily assessable.

Methods

We measured resting nailfold capillary blood flow in 67 POAG and 63 control subjects using video capillaroscopy. Masked readers tracked blood column voids between consecutive, registered image sequence frames, measured vessel diameter and calculated blood flow. We used multiple logistic regression to investigate the relation between nailfold capillary blood flow and POAG. In secondary analyses, we stratified cases by maximum IOP and concurrent topical beta-blocker use.

Results

Mean (±SD) blood flow in picolitres per second was 26.8±17.6 for POAG cases and 50.1±24.2 for controls (p<0.0001). After adjustment for demographic and clinical factors including blood pressure and pulse, every picolitre per second increase in resting nailfold blood flow was associated with a 6% (95% CI 0.92 to 0.96) reduced odds of POAG (p<0.0001). Similar relations between nailfold capillary blood flow and POAG were found for cases stratified by maximum known IOP and for cases stratified by concurrent topical beta-blocker use.

Conclusion

Reduced resting nailfold capillary blood flow is present in POAG independent of covariates such as blood pressure, pulse and IOP.

Fundus Densitometry Findings Suggest Optic Disc Hemorrhages in Primary Open-Angle Glaucoma Have an Arterial Origin

PURPOSE

To analyze optic disc hemorrhages (DH) associated with primary open-angle glaucoma by quantifying their geometric profile and comparing their densitometry with hemorrhages from retinal vein occlusions (RVO) and retinal macroaneurysms (MA), which have venous and arterial sources of bleeding, respectively.

DESIGN

Retrospective cross-sectional study.

METHODS

Setting: Massachusetts Eye & Ear.

POPULATION

Fundus images of DH (n = 40), MA (n = 14), and RVO (n = 25) were identified. Patient clinical backgrounds and demographics were obtained.

MAIN OUTCOME MEASURES

Grayscale pixel intensity units of hemorrhages and adjacent arteriole and venule over the same background tissue were measured. Densitometry differentials (arteriole or venule minus hemorrhage [ΔA and ΔV, respectively]) were calculated. The ratios of length (radial) to midpoint width for DH were calculated. Mean ΔA and ΔV between groups were compared with t tests. Multiple linear regression assessed the relation of retinal hemorrhage diagnosis to ΔA and ΔV and of DH shape to ΔA and ΔV.

RESULTS

Mean (± standard deviation) ΔA and ΔV for DH (6.9 ± 7.1 and -4.7 ± 8.0 pixel intensity units, respectively) and MA (5.3 ± 5.9 and -6.0 ± 4.6, respectively) were comparable (P ≥ .43). Mean ΔA (14.6 ± 7.7) and ΔV (6.4 ± 6.3) for RVO were significantly higher compared to DH and MA (P < .0001) and remained significant in multivariable analyses. A unit increase in DH length-to-width ratio was associated with 1.2 (0.5) and 1.3 (0.5) pixel intensity unit (standard error) decrease in ΔA and ΔV, respectively (P ≤ .014).

CONCLUSIONS

DH have densitometry profiles comparable to MA and different from RVO, suggesting that DH in glaucoma have an arterial origin.

Chemical Burns of the Eye: The Role of Retinal Injury and New Therapeutic Possibilities

PURPOSE

To propose a new treatment paradigm for chemical burns to the eye - in the acute and chronic phases.

METHODS

Recent laboratory and clinical data on the biology and treatment of chemical burns are analyzed.

RESULTS

Corneal blindness from chemical burns can now be successfully treated with a keratoprosthesis, on immediate and intermediate bases. Long term outcomes, however, are hampered by early retinal damage causing glaucoma. New data suggest that rapid diffusion of inflammatory cytokines posteriorly (TNF-α, etc) can severely damage the ganglion cells. Prompt anti-TNF-α treatment is markedly neuroprotective. Long term profound reduction of the intraocular pressure is also vital.

CONCLUSION

A new regimen, in addition to standard treatment, for severe chemical burns is proposed. This involves tumor necrosis factor alpha (TNF-α) inhibition promptly after the accident (primarily for retinal neuroprotection), prophylactic maximal lowering of the intraocular pressure (starting immediately), and keratoprosthesis implantation in a later quiet state.

Thin minimal rim width at Bruch's membrane opening is associated with glaucomatous paracentral visual field loss

Purpose

To compare optic nerve head (ONH) measurements in glaucomatous eyes with paracentral visual field (VF) loss to eyes with peripheral VF loss and controls.

Methods

Open-angle glaucoma (OAG) patients with early paracentral VF loss or isolated peripheral VF loss as well as control subjects underwent ONH imaging with swept-source optical coherence tomography (OCT) and retinal nerve fiber layer (RNFL) imaging with spectral-domain OCT. Minimum rim width at Bruch's membrane opening (BMO-MRW), lamina cribrosa depth (LCD), and RNFL thickness were compared among the glaucoma and control groups with one-way analysis of variance, Kruskal-Wallis test, and multiple regression analysis.

Results

Twenty-nine eyes from 29 OAG patients (15 early paracentral and 14 isolated peripheral VF loss) and 20 eyes of 20 control subjects were included. The early paracentral and isolated peripheral VF loss groups had similar VF mean deviation (MD) (-5.3±2.7 dB and -3.7±3.0 dB, p=0.15, respectively). Global BMO-MRW was lower in OAG eyes than in controls (193.8±40.0 vs 322.7±62.2 μm, p<0.001), but similar between eyes with early paracentral VF loss and those with isolated peripheral VF loss (187.6±43.4 vs 200.6±36.3 μm; p>0.99). In contrast, the minimal BMO-MRW was lower in eyes with early paracentral loss (69.0±33.6 μm) than in eyes with isolated peripheral loss (107.7±40.2 μm; p=0.03) or control eyes (200.1±40.8 μm; p<0.001). Average and thinnest RNFL thickness did not differ between OAG groups (p=0.61 and 0.19, respectively). Horizontal and vertical LCD did not differ among the OAG groups and controls (p=0.80 and 0.82, respectively). Multivariable linear regression analysis among OAG cases confirmed the association between lower minimal BMO-MRW and early paracentral VF loss (β=-38.3 μm; 95% confidence interval, -69.8 to -6.8 μm; p=0.02) after adjusting for age, gender, MD, and disc size.

Conclusion

Thin minimal BMO-MRW may represent a new structural biomarker associated with early glaucomatous paracentral VF loss.

A retrospective study on the outcomes of Ahmed valve versus Ahmed valve combined with fluocinolone implant in uveitic glaucoma

Purpose

To compare the intraocular pressure (IOP) outcomes of Ahmed glaucoma valve (AGV) surgery alone versus AGV with fluocinolone implant in uveitic glaucoma patients.

Methods

We identified uveitic glaucoma patients with AGV surgery alone and AGV surgery combined with fluocinolone implant from the Massachusetts Eye and Ear Ocular Inflammation Database. Demographic information, visual acuity, and IOP were recorded at preoperative visits and 1, 6, and 12 months after surgery. Incidence of hypertensive phase, defined as an IOP of >21 mm Hg or use of additional treatment to lower IOP occurring any time between 7 days to 6 months postoperatively, was investigated. Multilevel mixed effects models were performed to compare the outcomes between groups.

Results

Eighteen eyes of 13 uveitic glaucoma patients with 1-year follow-up data were included. There were 11 eyes of 9 patients (mean age, 56.5 years; 63.6% male) in the AGV group and 7 eyes of 4 patients (mean age, 61.3 years; 71.4% male) in the AGV + fluocinolone group. There was no significant difference in visual acuity change at 1 year after surgery between groups (P = 0.25), although visual acuity improvement was significant in the AGV group (P = 0.01). The hypertensive phase occurred in 91% of AGV patients and 43% of AGV + fluocinolone patients (P = 0.30), with onset of 8-40 days (mean, 18 days) after surgery. IOP and number of glaucoma medications decreased at the 1-year postoperative visits in both the AGV group (P < 0.0001, P < 0.0001) and the AGV + fluocinolone group (P = 0.001, P < 0.0001). Compared to the AGV group, the AGV + fluocinolone group used fewer glaucoma medications (0.28 vs 1.30 [P = 0.01]) and had better inflammation control (P = 0.02). The surgical complication rates were similar between groups.

Conclusions

In uveitic glaucoma, AGV with fluocinolone achieves a similar, desired IOP control but with fewer glaucoma medications than AGV alone.

Reversal of Glaucoma Hemifield Test Results and Visual Field Features in Glaucoma

PURPOSE

To develop a visual field (VF) feature model to predict the reversal of glaucoma hemifield test (GHT) results to within normal limits (WNL) after 2 consecutive outside normal limits (ONL) results.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Visual fields of 44 503 eyes from 26 130 participants.

METHODS

Eyes with 3 or more consecutive reliable VFs measured with the Humphrey Field Analyzer (Swedish interactive threshold algorithm standard 24-2) were included. Eyes with ONL GHT results for the 2 baseline VFs were selected. We extracted 3 categories of VF features from the baseline tests: (1) VF global indices (mean deviation [MD] and pattern standard deviation), (2) mismatch between baseline VFs, and (3) VF loss patterns (archetypes). Logistic regression was applied to predict the GHT results reversal. Cross-validation was applied to evaluate the model on testing data by the area under the receiver operating characteristic curve (AUC). We ascertained clinical glaucoma status on a patient subset (n = 97) to determine the usefulness of our model.

MAIN OUTCOME MEASURES

Predictive models for GHT results reversal using VF features.

RESULTS

For the 16 604 eyes with 2 initial ONL results, the prevalence of a subsequent WNL result increased from 0.1% for MD < -12 dB to 13.8% for MD ≥-3 dB. Compared with models with VF global indices, the AUC of predictive models increased from 0.669 (MD ≥-3 dB) and 0.697 (-6 dB ≤ MD < -3 dB) to 0.770 and 0.820, respectively, by adding VF mismatch features and computationally derived VF archetypes (P < 0.001 for both). The GHT results reversal was associated with a large mismatch between baseline VFs. Moreover, the GHT results reversal was associated more with VF archetypes of nonglaucomatous loss, severe widespread loss, and lens rim artifacts. For a subset of 97 eyes, using our model to predict absence of glaucoma based on clinical evidence after 2 ONL results yielded significantly better prediction accuracy (87.7%; P < 0.001) than predicting GHT results reversal (68.8%) with a prescribed specificity 67.7%.

CONCLUSIONS

Using VF features may predict the GHT results reversal to WNL after 2 consecutive ONL results.

Impact of Natural Blind Spot Location on Perimetry

We study the spatial distribution of natural blind spot location (NBSL) and its impact on perimetry. Pattern deviation (PD) values of 11,449 reliable visual fields (VFs) that are defined as clinically unaffected based on summary indices were extracted from 11,449 glaucoma patients. We modeled NBSL distribution using a two-dimensional non-linear regression approach and correlated NBSL with spherical equivalent (SE). Additionally, we compared PD values of groups with longer and shorter distances than median, and larger and smaller angles than median between NBSL and fixation. Mean and standard deviation of horizontal and vertical NBSL were 14.33° ± 1.37° and −2.06° ± 1.27°, respectively. SE decreased with increasing NBSL (correlation: r = −0.14, p < 0.001). For NBSL distances longer than median distance (14.32°), average PD values decreased in the upper central (average difference for significant points (ADSP): −0.18 dB) and increased in the lower nasal VF region (ADSP: 0.14 dB). For angles in the direction of upper hemifield relative to the median angle (−8.13°), PD values decreased in lower nasal (ADSP: −0.11 dB) and increased in upper temporal VF areas (ADSP: 0.19 dB). In conclusion, we demonstrate that NBSL has a systematic effect on the spatial distribution of VF sensitivity.

Relationship Between Central Retinal Vessel Trunk Location and Visual Field Loss in Glaucoma

PURPOSE

To study the relationship between horizontal central retinal vessel trunk location (CRVTL) on glaucomatous optic discs and sector-specific visual field (VF) loss.

DESIGN

Retrospective cross-sectional study.

METHODS

CRVTL of 421 eyes from 421 patients was manually tracked on the horizontal optic disc axis on fundus images. Focal circumpapillary retinal nerve fiber layer thickness (cpRNFLT) measurements were extracted from optical coherence tomography (OCT). The relationship between focal visual field (VF) loss and CRVTL and focal cpRNFLT was studied by linear regression models. Furthermore, we related central VF loss to CRVTL and focal cpRNFLT separately for mild (VF mean deviation [MD] ≥-6 dB), moderate (-12 dB ≤ MD <-6 dB), and severe (MD <-12 dB) glaucoma.

RESULTS

CRVTL nasalization was significantly correlated only to central VF loss (Garway-Heath scheme [central 6 locations, C6]: correlation: r = -0.16, P < .001; macular vulnerability zone [central 2 locations, C2]: r = -0.14, P = .003; central 4 locations [C4]: r = -0.17, P < .001). While focal cpRNFLT at the sectors corresponding to C2 and C6 was significantly correlated to the respective VF sectors as well (C2: r = 0.15, P = .002; C6: r = 0.10, P = .03), multivariate models combining cpRNFLT and CRVTL substantially improved structure-function models compared with cpRNFLT alone (likelihood ratio tests, C2 and C6: P < .001). The correlations between CRVTL and central VF loss of C4 were -0.11 (P = .04), -0.39 (P = .01), and -0.63 (P = .002) for mild, moderate, and severe glaucoma, respectively.

CONCLUSIONS

CRVTL nasalization is significantly and exclusively correlated to central VF loss for all glaucoma severities independent of cpRNFLT, and thus might be a structural biomarker of central VF loss.

Clinical Correlates of Computationally Derived Visual Field Defect Archetypes in Patients from a Glaucoma Clinic

PURPOSE

To assess the clinical validity of visual field (VF) archetypal analysis, a previously developed machine learning method for decomposing any Humphrey VF (24-2) into a weighted sum of clinically recognizable VF loss patterns.

MATERIALS AND METHODS

For each of 16 previously identified VF loss patterns ("archetypes," denoted AT1 through AT16), we screened 30,995 reliable VFs to select 10-20 representative patients whose VFs had the highest decomposition coefficients for each archetype. VF global indices and patient ocular and demographic features were extracted retrospectively. Based on resemblances between VF archetypes and clinically observed VF patterns, hypotheses were generated for associations between certain VF archetypes and clinical features, such as an association between AT6 (central island, representing severe VF loss) and large cup-to-disk ratio (CDR). Distributions of the selected clinical features were compared between representative eyes of certain archetypes and all other eyes using the two-tailed t-test or Fisher exact test.

RESULTS

243 eyes from 243 patients were included, representative of AT1 through AT16. CDR was more often ≥ 0.7 among eyes representative of AT6 (central island; p = 0.002), AT10 (inferior arcuate defect; p = 0.048), AT14 (superior paracentral defect; p = 0.016), and AT16 (inferior paracentral defect; p = 0.016) than other eyes. CDR was more often < 0.7 among eyes representative of AT1 (no focal defect; p < 0.001) and AT2 (superior defect; p = 0.027), which was also associated with ptosis (p < 0.001). AT12 (temporal hemianopia) was associated with history of stroke (p = 0.022). AT11 (concentric peripheral defect) trended toward association with trial lens correction > 6D (p = 0.069).

CONCLUSIONS

Shared clinical features between computationally derived VF archetypes and clinically observed VF patterns support the clinical validity of VF archetypal analysis.

Infliximab after Boston Keratoprosthesis in Stevens-Johnson Syndrome: An Update

PURPOSE

To report our experience using intravenous infliximab for the treatment of tissue melt after Boston keratoprosthesis (B-KPro) types I and II in patients with autoimmune disease.

METHODS

Case series.

RESULTS

We identified four patients who were treated with intravenous infliximab in the context of tissue melt after B-KPro. Stevens-Johnson syndrome-associated corneal blindness was the primary surgical indication for B-KPro implantation in all patients. Two patients received a B-KPro type I and two patients received a B-KPro type II. The patients received intravenous infliximab for skin retraction around B-KPro type II, melting of the carrier graft or leak. Treatment resulted in a dramatic decrease in inflammation and, in some cases, arrest of the melting process. Cost and patient adherence were limiting factors to pursuing infliximab therapy. In addition, one patient developed infusion reactions.

CONCLUSIONS

Intravenous infliximab may be considered as globe- and sight-saving therapy for tissue melt after B-KPro.

Patterns of functional vision loss in glaucoma determined with archetypal analysis

Glaucoma is an optic neuropathy accompanied by vision loss which can be mapped by visual field (VF) testing revealing characteristic patterns related to the retinal nerve fibre layer anatomy. While detailed knowledge about these patterns is important to understand the anatomic and genetic aspects of glaucoma, current classification schemes are typically predominantly derived qualitatively. Here, we classify glaucomatous vision loss quantitatively by statistically learning prototypical patterns on the convex hull of the data space. In contrast to component-based approaches, this method emphasizes distinct aspects of the data and provides patterns that are easier to interpret for clinicians. Based on 13 231 reliable Humphrey VFs from a large clinical glaucoma practice, we identify an optimal solution with 17 glaucomatous vision loss prototypes which fit well with previously described qualitative patterns from a large clinical study. We illustrate relations of our patterns to retinal structure by a previously developed mathematical model. In contrast to the qualitative clinical approaches, our results can serve as a framework to quantify the various subtypes of glaucomatous visual field loss.