Visual Field Changes Research Articles

A multi-label transformer-based deep learning approach to predict focal visual field progression.

Tracking functional changes in visual fields (VFs) through standard automated perimetry remains a clinical standard for glaucoma diagnosis. This study aims to develop and evaluate a deep learning (DL) model to predict regional VF progression, which has not been explored in prior studies. The study included 2430 eyes of 1283 patients with four or more consecutive VF examinations from the baseline. A multi-label transformer-based network (MTN) using longitudinal VF data was developed to predict progression in six VF regions mapped to the optic disc. Progression was defined using the mean deviation (MD) slope and calculated for all six VF regions, referred to as clusters. Separate MTN models, trained for focal progression detection and forecasting on various numbers of VFs as model input, were tested on a held-out test set. The MTNs overall demonstrated excellent macro-average AUCs above 0.884 in detecting focal VF progression given five or more VFs. With a minimum of 6 VFs, the model demonstrated superior and more stable overall and per-cluster performance, compared to 5 VFs. The MTN given 6 VFs achieved a macro-average AUC of 0.848 for forecasting progression across 8 VF tests. The MTN also achieved excellent performance (AUCs ≥ 0.86, 1.0 sensitivity, and specificity ≥ 0.70) in four out of six clusters for the eyes already with severe VF loss (baseline MD ≤ - 12dB). The high prediction accuracy suggested that multi-label DL networks trained with longitudinal VF results may assist in identifying and forecasting progression in VF regions.

Rates of visual field change and functional progression in glaucoma following trabecular microbypass implantation of iStent technologies: a meta-analysis

Background/aimWhile intraocular pressure (IOP) remains the only modifiable risk factor for glaucoma progression, the ultimate goal of glaucoma management is to preserve patients’ functional vision and quality of life. To...

Longitudinal changes in optical coherence tomography angiography characteristics in normal-tension glaucoma with or without high myopia.

To evaluate the structural, microvascular, and functional progression of normal tension glaucoma (NTG) with or without high myopia by examining longitudinal changes in optical coherence tomography angiography (OCTA) and visual field (VF) parameters. We evaluated 61 NTG eyes and classified 25 of the eyes with axial lengths (ALs) of ≥26 mm as highly myopic. We assessed the rate of change in OCTA parameters, namely radial peripapillary capillary (RPC) vessel density (VD), parafovea VD, deep parafovea VD, retinal nerve fibre layer (RNFL) thickness, and ganglion cell complex thickness. We evaluated the correlation of the rate of change in OCTA parameters with VF loss and AL. Among the 61 NTG eyes, rates of loss of RPC VD, parafovea VD, deep parafovea VD, and RNFL thickness were significantly different from zero despite the nonsignificant rate of change in VF mean deviation (MD). Changes in these OCTA parameters did not differ significantly in highly myopic NTG eyes. The rate of change in VF MD was significantly correlated with the rate of change in parafovea VD in highly myopic and non-highly myopic NTG eyes. In highly myopic NTG eyes, AL was negatively correlated with the rates of loss of RNFL thickness, VF MD, and VF PSD. NTG eyes with a relatively stable VF exhibited loss of VD and RNFL thickness. VF progression in NTG was correlated with decreasing parafovea VD, indicating a structure-function correlation. Greater AL may indicate faster VF loss and RNFL thinning in highly myopic NTG eyes.

Comparison of the Circumpapillary Structure-Function and Vasculature-Function Relationships at Different Glaucoma Stages Using Longitudinal Data.

This study investigated the global and regional correlations between longitudinal structure-function (S-F) and vasculature-function (V-F) data using circumpapillary retinal nerve fiber layer thickness (cpRNFLT) measurements from optical coherence tomography (OCT), circumpapillary vessel density (cpVD) from OCT angiography (OCTA), and the corresponding visual field mean sensitivities at different glaucoma stages. A total of 107 eyes from 107 glaucoma patients with progressive visual field (VF) changes followed up for an average of 3.33 ± 1.39years were enrolled, including early-to-moderate (51 eyes) and advanced (56 eyes) stages. The rates of longitudinal change in the VF mean deviation (MD), cpRNFLT, and cpVD were evaluated using linear mixed-effects models and compared between different glaucoma stages. Longitudinal global and regional S-F and V-F relationships were assessed by repeated measures correlation analysis by glaucoma stage. No significant differences were found in the rates of VF MD and cpVD changes (P > 0.05) between the two glaucoma stage groups. CpRNFLT decreased more rapidly in the early-to-moderate stage group (P < 0.001) in which significant longitudinal global and regional correlations were found in both S-F and V-F relationships (all P < 0.05), except for the nasal sector. Significant global and regional correlations were only found in V-F relationship in advanced stage cases (all P < 0.05). Significant longitudinal V-F relationships exist globally and regionally regardless of glaucoma stage but no longitudinal S-F relationship is present in advanced glaucoma. Longitudinal follow-up of cpVD parameters may be useful for monitoring glaucomatous VF progression at all disease stages.

Changes in peripheral visual field perception after intraocular lens implantation

Aims/Purpose: To assess whether the eccentricity of the perception of objects in the peripheral visual field changes when a crystalline lens is replaced by an intraocular lens (IOL).Methods: The effect of the IOL on the eccentricity at which peripheral objects are perceived was assessed using phakic and pseudophakic versions of the same eye model. Non‐sequential ray tracing simulations were used to determine the relation between the input eccentricity at which an object was positioned in the visual field and the corresponding eccentricity at which the object was perceived by the eye in every eye model. Two different IOL designs were evaluated in the pseudophakic eye model. For each IOL design five different axial positions and seven different intrinsic powers were tested. Subsequently, the results of the pseudophakic eye models were compared to the results of the phakic model.Results: For central vision, the perceived eccentricity differed less than 1 degree between the phakic and pseudophakic models. For peripheral vision, the light rays were refracted to a more central retinal location in pseudophakic eyes than in phakic eyes, therewith shifting perceived eccentricity. The amount of the perceived shift depended on the IOL design and its axial position. The maximal shift within the evaluated pseudophakic models was 5.4 degrees towards central vision.Conclusions: IOL implantation has a minor effect on how the central visual field is perceived, but it can alter the eccentricity at which objects in the peripheral visual field are perceived by over 5 degrees. Such a shift in eccentricity can, for instance, affect how peripheral visual complaints, such as negative dysphotopsia, are experienced.

One-year experience with latanoprostene bunod ophthalmic solution 0.024% in clinical practice: A retrospective observational study.

We evaluated the IOP-lowering efficacy and safety of latanoprostene bunod (LBN) ophthalmic solution 0.024% (Vyzulta®), the first topical nitric oxide-donating prostaglandin analog (PGA), in clinical practice. A retrospective medical chart review from July 2021 to July 2023 of patients with open-angle glaucoma receiving LBN with at least 1 year follow-up was conducted. All included patients received LBN 0.024% as a replacement for a PGA, with examinations at 1-, 3-, 6-and 12-months follow-up. Main outcome measures were IOP, retinal nerve fiber layer thickness, visual fields before/after LBN use and adverse effects. Subgroup analysis with glaucoma types and PGA use were performed for additional IOP reduction after LBN use. Among 78 included patients, 47 patients (81 eyes), 60% with open-angle glaucoma (OAG) remained on LBN throughout 12-month follow-up. Baseline IOP was 18.2±4.2 mm Hg, and Prostaglandin analog (PGA)-IOP was 14.4 ± 3.0 mm Hg (21% mean IOP reduction). After switched to LBN, mean additional IOP reduction was 1.0 mm Hg at month 1, and the greatest reduction was 1.6 mm Hg (8.8% additional mean IOP reduction) at month 12 (P<0.0001). Subgroup analysis (NTG, 73%) showed that mean additional IOP reduction at month 12 was 1.3±2.0 mm Hg in NTG group and 2.1±3.2 mm Hg in POAG group (7.7% vs. 8.7% additional IOP reduction rates, P = 0.23). Subgroup analysis of PGA use at month 12 was 1.8±2.3 mm Hg in tafluoprost group and 0.5±1.7 mm Hg in travoprost group (9.5% vs.2.6% additional IOP reduction rates, P = 0.02). Tolerable ocular adverse effects included irritation (n = 16, 19.8%), mild conjunctival hyperemia (n = 11, 13.6%), dark circles (n = 4, 4.9%) and blurred vision (n = 2, 2.5%). There were no significant visual field and retinal nerve fiber layer thickness changes after 12 months of treatment with LBN 0.024%. Although high intolerable adverse effects including conjunctival hyperemia and eye irritation happened in the first month, remaining sixty percent of patients exhibited statistically significant additional IOP reductions in the replacement of other PGAs during 12 months of clinical use of LBN 0.024%.

Analysis of the efficacy of transnasal endoscopic annulus of zinn area decompression in the treatment of dysthyroid optic neuropathy

Objective: To evaluate the early efficacy and safety of transnasal endoscopic decompression in the annulus of zinn (AZ) region for refractory dysthyroid optic neuropathy (DON) and to preliminarily analyze the correlated factors of postoperative visual function outcome. Methods: From July 2021 to January 2023, 35 patients (56 eyes) with DON who received AZ area decompression in Peking University Third Hospital were included retrospectively, including 9 males (13 eyes) and 26 females (43 eyes), aging (52.2±12.0) years. Among them, 35 eyes underwent two-wall (medial and inferior) orbital decompression using an endonasal endoscopic approach, while 21 eyes received three-wall (medial, lateral, and inferior) orbital decompression through a combined approach. Key parameters such as best corrected visual acuity (BCVA), visual field (MD value), eyeball prominence, intraocular pressure, and complications were recorded. Postoperative data were collected one month after surgery. The statistical analysis was performed using paired t-test and Spearman correlation analysis. Results: Significant outcomes were observed post surgery in BCVA, visual field, intraocular pressure and proptosis (t value was 8.37, 6.17, 4.50, and 9.20, respectively, all P<0.001). The reduction in proptosis was statistically significant between the 2-wall and 3-wall orbital decompression groups (t=-2.82, P=0.007). Changes in BCVA, visual field, and intraocular pressure before and after surgery was greater in the 3-wall orbital decompression group compared to 2-wall orbital decompression group, although the difference was not statistically significant (all P>0.05). Change in postoperative visual acuity and visual field was significantly positively correlated with preoperative visual acuity and preoperative visual field (all P<0.001). Similarly, change in intraocular pressure and proptosis was positively correlated with preoperative intraocular pressure and preoperative protrusion (all P<0.001). Preoperative diplopia was reported in seven patients (20.0%), and two new cases (5.7%) were noted post-operation, which resolved within 3 months after surgery. Conclusions: Endoscopic endonasal decompression of the AZ area is a safe and effective surgical treatment for DON, with notable improvements in BCVA. Furthermore, three-orbital wall decompression seems to yield better outcomes in terms of eye retraction.

Predicting glaucoma progression using deep learning framework guided by generative algorithm

Glaucoma is a slowly progressing optic neuropathy that may eventually lead to blindness. To help patients receive customized treatment, predicting how quickly the disease will progress is important. Structural assessment using optical coherence tomography (OCT) can be used to visualize glaucomatous optic nerve and retinal damage, while functional visual field (VF) tests can be used to measure the extent of vision loss. However, VF testing is patient-dependent and highly inconsistent, making it difficult to track glaucoma progression. In this work, we developed a multimodal deep learning model comprising a convolutional neural network (CNN) and a long short-term memory (LSTM) network, for glaucoma progression prediction. We used OCT images, VF values, demographic and clinical data of 86 glaucoma patients with five visits over 12 months. The proposed method was used to predict VF changes 12 months after the first visit by combining past multimodal inputs with synthesized future images generated using generative adversarial network (GAN). The patients were classified into two classes based on their VF mean deviation (MD) decline: slow progressors (< 3 dB) and fast progressors (> 3 dB). We showed that our generative model-based novel approach can achieve the best AUC of 0.83 for predicting the progression 6 months earlier. Further, the use of synthetic future images enabled the model to accurately predict the vision loss even earlier (9 months earlier) with an AUC of 0.81, compared to using only structural (AUC = 0.68) or only functional measures (AUC = 0.72). This study provides valuable insights into the potential of using synthetic follow-up OCT images for early detection of glaucoma progression.

Glaucoma after penetrating keratoplasty and keratoprosthesis

To compare visual and glaucoma outcomes in patients with known glaucoma after a penetrating keratoplasty (PKP) or a Boston Keratoprosthesis Type 1 (KPro) as a second corneal replacement procedure. Retrospective interventional case series. Charts of 141 eyes that underwent either a PKP or KPro at the Centre hospitalier de l'Université de Montréal after one failed PKP from 2008 to 2020 were reviewed. Forty-six eyes with preoperative glaucoma were included. Data collected included demographics, indication for the initial surgery, best corrected visual acuity (BCVA), concurrent ocular disorders, number of glaucoma medications, need for glaucoma surgery, cup-to-disc ratios (CDRs), mean RNFL thickness, and visual field (VF) characteristics. Primary outcomes were glaucoma progression trends. Secondary outcomes were visual outcomes and need for additional procedures. Mean follow-up was 4.7years for the PKP and 7.3 for the KPro group (P<0.007). 30.6% of PKP compared to 70.5% of KPro patients were diagnosed with glaucoma preoperatively. Glaucoma worsened similarly in both groups; this is based on an analysis of the number of glaucoma medications, CDR, need for glaucoma surgery, and characteristic VF changes. Patients in the PKP group required significantly more regrafts than patients in the KPro group (31.8 vs. 8.3%; P=0.045). A preoperative diagnosis of glaucoma does not preclude KPro implantation. In glaucomatous eyes, the disease progressed similarly in both groups. Since both procedures increase the risk of worsening glaucoma, close follow-up is recommended. KPro may decrease the need for further corneal transplantation surgery.

DISAPPEARING CHOROIDAL SPOTS ON OCT ANGIOGRAPHY PRECEDING RECURRENCE OF MULTIFOCAL CHOROIDITIS WITH CHORIORETINAL ATROPHY.

To describe idiopathic multifocal choroiditis (iMFC) with chorioretinal atrophy developing choroidal flow voids on optical coherence tomography angiography (OCTA) that preceded a recurrence of the disease. Case report. A 24-year-old woman presented with visual field changes and occasional photopsias. Systemic work-up for syphilis, tuberculosis, and sarcoidosis, was negative. Clinical findings and multimodal imaging were consistent with iMFC with chorioretinal atrophy, complicated by inactive choroidal neovascularization in her right eye. She was treated with systemic corticosteroids with a taper over 3 months without change in her examination. She was then stable for two years. At that point, the patient experienced increased photopsias, but her examination was unchanged. OCTA showed multiple flow voids in the choroid that were not present 6 months prior. No lesions were seen on other imaging modalities. Structural OCT showed some subtle hyper-reflectivity throughout the choroid that was previously absent. Given the unknown significance of these flow voids, the patient was asked to return for follow-up in one month. Her photopsias improved and her vision remained normal. On repeat examination after one month, the patient had developed a few subtle yellow lesions in the supero-nasal quadrant of the left eye. There were no macular lesions. The repeat OCTA revealed that the flow voids were fading. Imaging findings using OCTA in our patient with iMFC showed choroidal flow voids that preceded clinical recurrence, not detected by other imaging modalities. Future studies should determine if OCTA can be used to detect subclinical lesions preceding clinical recurrences of iMFC.

Reliability of intraoperative visual evoked potentials (iVEPs) in monitoring visual function during endoscopic transsphenoidal surgery

ObjectiveTo refine a reliable and reproducible intraoperative visual evoked potentials (iVEPs) monitoring protocol during endoscopic transsphenoidal surgery. To assess the reliability of baseline iVEPs in predicting preoperative visual status and perioperative iVEP variation in predicting postoperative visual outcome.MethodsSixty-four patients harboring tumors of the pituitary region were included. All patients underwent endoscopic endonasal approach (EEA) with iVEPs monitoring, using a totally intravenous anesthetic protocol. Ophthalmological evaluation included visual acuity and visual field studies.ResultsPreoperatively, visual acuity was reduced in 86% and visual field in 76.5% of cases. Baseline iVEPs amplitude was significantly correlated with preoperative visual acuity and visual field (p = 0.001 and p = 0.0004, respectively), confirming the reliability of the neurophysiological/anesthetic protocol implemented.Importantly, perioperatively the variation in iVEPs amplitude was significantly correlated with the changes in visual acuity (p < 0.0001) and visual field (p = 0.0013). ROC analysis confirmed that iVEPs are an accurate predictor of perioperiative visual acuity improvement, with a 100% positive predictive value in patients with preoperative vision loss.ConclusionsiVEPs during EEA is highly reliable in describing preoperative visual function and can accurately predict postoperative vision improvement.SignificanceiVEPs represent a promising resource for carrying out a more effective and safe endoscopic transsphenoidal surgery.

Utility of targeted mean total deviation trend analysis for detecting progressive visual field changes in early-to-moderate stage glaucoma.

To evaluate the clinical utility of trend-based analysis of the targeted mean total deviation (TMTD) by comparing its rates of visual field (VF) change and sensitivities of detecting VF progression with those of the mean total deviation (mTD) in the global and hemifield VF area in early to-moderate glaucoma patients. A single eye from 139 open-angle glaucoma patients with hemifield VF defects and a minimum two year follow-up were retrospectively evaluated. The TMTD was estimated by averaging the total deviation (TD) values after excluding VF points that had a threshold sensitivity of <0 dB in three baseline tests, and the mTD by averaging the entire VF TD values. The study patients were classified as VF progressors vs. non-progressors using both event- and trend-based analysis. The rates of change and ratios of progression detection were compared between TMTD and mTD. This study included 49 VF progressors and 90 non-progressors. Slopes for the global and VF-affected hemifield TMTD were significantly faster than those for the mTD in each subgroup and in the entire cohort (P < 0.001). Trend-based TMTD analysis detected VF progression in greater proportion than either trend-based mTD or event-based analysis (38.1% vs. 30.2% vs. 27.3%, respectively: VF affected hemifields). The rates of change in the TMTD are significantly faster than those for the mTD globally and in the VF-affected hemifields. Trend-based TMTD analysis shows greater sensitivity for detecting VF progression than trend-based mTD or event-based analysis in early-to-moderate glaucoma patients with hemifield VF loss.

A frontal transcallosal inhibition loop mediates interhemispheric balance in visuospatial processing

Interhemispheric communication through the corpus callosum is required for both sensory and cognitive processes. Impaired transcallosal inhibition causing interhemispheric imbalance is believed to underlie visuospatial bias after frontoparietal cortical damage, but the synaptic circuits involved remain largely unknown. Here, we show that lesions in the mouse anterior cingulate area (ACA) cause severe visuospatial bias mediated by a transcallosal inhibition loop. In a visual-change-detection task, ACA callosal-projection neurons (CPNs) were more active with contralateral visual field changes than with ipsilateral changes. Unilateral CPN inactivation impaired contralateral change detection but improved ipsilateral detection by altering interhemispheric interaction through callosal projections. CPNs strongly activated contralateral parvalbumin-positive (PV+) neurons, and callosal-input-driven PV+ neurons preferentially inhibited ipsilateral CPNs, thus mediating transcallosal inhibition. Unilateral PV+ neuron activation caused a similar behavioral bias to contralateral CPN activation and ipsilateral CPN inactivation, and bilateral PV+ neuron activation eliminated this bias. Notably, restoring interhemispheric balance by activating contralesional PV+ neurons significantly improved contralesional detection in ACA-lesioned animals. Thus, a frontal transcallosal inhibition loop comprising CPNs and callosal-input-driven PV+ neurons mediates interhemispheric balance in visuospatial processing, and enhancing contralesional transcallosal inhibition restores interhemispheric balance while also reversing lesion-induced bias.

Effect of Phacoemulsification Cataract Surgery on the Clinical Outcomes of Advanced Glaucoma Patients

Purpose: To identify the clinical outcomes of cataract surgery in patients with advanced glaucoma.Methods: A retrospective chart review of open-angle glaucoma patients who underwent cataract surgery and were followed-up for 1 year was conducted. Advanced glaucoma was defined as a mean deviation (MD) &lt; -12 dB on the preoperative visual field test. A group with mild-to-moderate glaucoma (MD ≥ -12 dB) served as the control group. Changes in intraocular pressure (IOP) at 1, 3, 6, and 12 months, and in the postoperative visual acuity (VA) as well as in the visual field indices (MD and the pattern standard deviation), and the number of antiglaucoma medications were compared.Results: Eighty-seven eyes (87 patients) of the advanced group and 109 eyes (109 patients) of the mild-to-moderate group were finally included. From 1 week to 24 months postoperatively, both groups evidenced IOP decreases compared to the preoperative values (both &lt;i&gt;p&lt;/i&gt; &lt; 0.05). The IOP spike prevalence was similar in the two groups (11% vs. 13%, &lt;i&gt;p&lt;/i&gt; = 0.199). The mean IOP difference between the two groups was not significant at months 1, 3, 6, 12, or 24 postoperatively (all &lt;i&gt;p&lt;/i&gt; &gt; 0.05). Both groups evidenced VA improvements at 1 year postoperatively and the visual field (VF) indices did not differ from those before surgery. The numbers of antiglaucoma medications used decreased after surgery, but the decrease was significant only in the advanced glaucoma group (&lt;i&gt;p&lt;/i&gt; = 0.030).Conclusions: The advanced and mild-to-moderate glaucoma groups evidenced similar IOP and VF changes after cataract surgery. The VA improved and the number of antiglaucoma medications decreased. Our findings suggest that cataract surgery for patients with advanced glaucoma may afford similar clinical outcomes compared to other less severe glaucoma groups.

Synonymous Myocilin mutations break their silence in a Zambian population attending selected referral eye health facilities

Objective: Primary open-angle glaucoma in Zambia has an earlier age of onset and appears to be more clinically severe. Myocilin mutations are associated with primary open angle glaucoma in multiple populations. Therefore, we investigated the role of myocilin gene mutations in Primary Open Angle Glaucoma in a Zambian population. Methods: The unrelated primary open-angle glaucoma patients and unaffected controls recruited were from the University Teaching Hospitals Eye Hospital, Kitwe Teaching Eye Hospital and Lusaka Adventist Eye Hospital. A complete eye examination, including visual field assessment, was performed in all cases and controls.Genomic DNA was extracted from whole peripheral blood, then subjected to polymerase chain reaction to amplify exons, flanking introns and promoter regions of the myocilingene. The amplified products were screened for base mutations by auto sequence based on the Sanger method. The analyses of findings included odds ratios, chi-square, bivariate, multivariate and conditional logistic regression with 95% confidence interval and at a 5% level of significance.There was also a comparison between the identified mutations and the previously reported myocilinmutations. Results: Unrelated 165 Primary Open-Angle Glaucoma patients and unaffected 173 controls enrolled for the study. The analysis revealed 4 variants of MYOC mutations in 49 participants of the 338. The mutations included one synonymous (silent) mutation (Thr474Thr; 45/338) and three missense mutations (Ala446Thr; 16/338), (Leu158Arg; 4/338) and (Arg342Lys; 1/338). The study observed two previously reported mutations, Ala446Thr and Arg342Lys, as glaucoma causing mutations. The missense mutation, Ala446Thr, was found in 16 participants who also had silent mutations broken down as eight cases and eight controls. One control had two variants, Ala446Thr and Arg342Lys. Twenty (20) controls and 25 cases had the synonymous or silent (neutral) mutation, (Thr474Thr). The occurrence of Thr474Thr and Ala446Thr in the same cases and controls was compelling evidence to think that the synonymous mutations were not as silent as previously reported. The Thr474Thr and Ala446Thr mutations exhibited identical primary open-angle glaucomaphenotypic features in both cases and controls. In the remaining 17 cases and 12 controls the phenotype were still the same. The clinical profile in Thr474Thr mutation was statistically significant for female gender, younger age group (&lt;40 years), older age group (≥ 65 years), positive family history, poor visual acuity, severe visual field changes, diffuse retinal nerve fibre layer defects, peripapillary atrophy surrounding the optic nerve head and high cup disc ratio between 0.8 and 1.0 Conclusions: The silent myocilin mutations, Thr474Thr, break their silence in a Zambian population. The silent mutation Thr474Thr found was associated with primary open-angle glaucoma phenotype and appeared to be a glaucoma-causing.

Relationship of Choroidal Microvasculature Dropout and Beta Zone Parapapillary Area With Visual Field Changes in Glaucoma

To evaluate the association between rates of choroidal microvasculature dropout (MvD) change, beta zone parapapillary atrophy (β-PPA) area change, and visual field (VF) changes in eyes with primary open-angle glaucoma (POAG). Retrospective, observational cohort study. In a tertiary glaucoma clinic, we included 76 eyes from 58 patients with POAG with and without localized MvD, who had ≥2 years of follow-up with a minimum of 4 visits with optical coherence tomography angiography and optical coherence tomography scans. β-PPA area was evaluated using scanning laser ophthalmoscopy-like images and compared with the area of MvD on an en face choroidal vessel density map during the follow-up period. Joint longitudinal mixed effects models were used to estimate the rates of change in β-PPA area or MvD area and VF mean deviation (MD). Mean rates of change in β-PPA and MvD area were 0.037 mm2 (95% confidence interval [CI] 0.030-0.043 mm2) per year and 0.039 mm2 (95% CI 0.029-0.048 mm2) per year, respectively, over the mean follow-up of 4.1 years. In multivariable models, MvD area enlargement was significantly associated with faster rates of VF MD loss (0.03 mm2 [95% CI 0.02-0.04 mm2] per 1-dB worse, P < .001) but not β-PPA area enlargement (0.04 mm2 [95% CI 0.03-0.05 mm2] per 1-dB worse, P=.252). MvD area rates, but not β-PPA area rates, were associated with VF MD loss changes in eyes with POAG. Assessment of MvD is useful for the detection of patients with glaucoma who are at an increased risk of faster VF loss.

Hypoxia impairs reaction time but not response accuracy in a visual choice reaction task

We investigated the effect of hypoxia on the reaction time (RT) and response accuracy of pilots performing a visual choice reaction task that corresponded to the scanning of helmet mounted display (HMD) symbology. Eighteen male military pilots performed the task in a hypobaric chamber at two simulated altitudes (92 m and 4572 m) in a single-blinded repeated measures and counter-balanced design. The visual stimuli were displayed in low and high contrast and at a 30- and 50-degree field of view (FoV). We measured the pilots' RT and response accuracy. Using an eye tracker, we measured the pilot's glance time at each stimulus location. Finally, we collected subjective ratings of alertness. The results show that hypoxia increased the RT and glance time. Lowering the stimulus contrast and increasing the FoV further increased the RT, independent of hypoxia. These findings provide no evidence for hypoxia-induced changes in visual contrast sensitivity or visual field. Instead, hypoxia seemed to affect RT and glance time by reducing alertness. Despite the increased RT, the pilots maintained their accuracy on the visual task, suggesting that visual scanning of HMD symbology may be resistant to the effects of acute hypoxia.

Segmentation-Free OCT-Volume-Based Deep Learning Model Improves Pointwise Visual Field Sensitivity Estimation.

The structural changes measured by optical coherence tomography (OCT) are related to functional changes in visual fields (VFs). This study aims to accurately assess the structure-function relationship and overcome the challenges brought by the minimal measurable level (floor effect) of segmentation-dependent OCT measurements commonly used in prior studies. We developed a deep learning model to estimate the functional performance directly from three-dimensional (3D) OCT volumes and compared it to the model trained with segmentation-dependent two-dimensional (2D) OCT thickness maps. Moreover, we proposed a gradient loss to utilize the spatial information of VFs. Our 3D model was significantly better than the 2D model both globally and pointwise regarding both mean absolute error (MAE = 3.11 + 3.54 vs. 3.47 ± 3.75 dB, P < 0.001) and Pearson's correlation coefficient (0.80 vs. 0.75, P < 0.001). On a subset of test data with floor effects, the 3D model showed less influence from floor effects than the 2D model (MAE = 5.24 ± 3.99 vs. 6.34 ± 4.58 dB, P < 0.001, and correlation 0.83 vs. 0.74, P < 0.001). The gradient loss improved the estimation error for low-sensitivity values. Furthermore, our 3D model outperformed all prior studies. By providing a better quantitative model to encapsulate the structure-function relationship more accurately, our method may help deriving VF test surrogates. DL-based VF surrogates not only benefit patients by reducing the testing time of VFs but also allow clinicians to make clinical judgments without the inherent limitations of VFs.

What is the Optimal Frequency of Visual Field Testing to Detect Rapid Progression Among Hypertensive Eyes?

We evaluated 16,351 visual field (VF) tests from Ocular Hypertension Treatment Study (OHTS) database and showed that more frequent testing resulted in a shorter time to detect glaucoma progression, with the best trade-off being the 6-month intervals for high-risk and 12 months for low-risk patients. To investigate the effect of different testing intervals on time to detect visual field progression in eyes with ocular hypertension. A total of 16,351 reliable 30-2 VF tests from 1575 eyes of the OHTS-1 observation arm with a mean (95% CI) follow-up of 4.8 (4.7-4.8) years were analyzed. Computer simulations (n = 10,000 eyes) based on mean deviation values and the residuals of risk groups (according to their baseline 5 y risk of developing primary open angle glaucoma: low, medium, and high risk) were performed to estimate time to detect progression with testing intervals of 4, 6, 12, and 24 months using linear regression. The time to detect VF progression ( P < 5%) at 80% power was calculated based on the mean deviation slope of -0.42 dB/year. We assessed the time to detect a -3 dB loss as an estimate of clinically meaningful perimetric loss. At 80% power, based on the progression of -0.42 dB/year, the best trade-off to detect significant rates of VF change to clinically meaningful perimetric loss in high, medium, and low-risk patients was 6, 6, and 12-month intervals, respectively. Given the importance of not missing the conversion to glaucoma, the frequency of testing used in OHTS (6 mo) was optimal for the detection of progression in high-risk patients. Low-risk patients could potentially be tested every 12 months to optimize resource utilization.

Causal factors in primary open angle glaucoma: a phenome-wide Mendelian randomisation study

Primary open angle glaucoma (POAG) is a chronic, adult-onset optic neuropathy associated with characteristic optic disc and/or visual field changes. With a view to identifying modifiable risk factors for this common neurodegenerative condition, we performed a ‘phenome-wide’ univariable Mendelian randomisation (MR) study that involved analysing the relationship between 9661 traits and POAG. Utilised analytical approaches included weighted mode based estimation, the weighted median method, the MR Egger method and the inverse variance weighted (IVW) approach. Eleven traits related to POAG risk were identified including: serum levels of the angiopoietin-1 receptor (OR [odds ratio] = 1.11, IVW p = 2.34E-06) and the cadherin 5 protein (OR = 1.06, IVW p = 1.31E-06); intraocular pressure (OR = 2.46–3.79, IVW p = 8.94E-44–3.00E-27); diabetes (OR = 5.17, beta = 1.64, IVW p = 9.68E-04); and waist circumference (OR = 0.79, IVW p = 1.66E-05). Future research focussing on the effects of adiposity, cadherin 5 and angiopoietin-1 receptor on POAG development and progression is expected to provide key insights that might inform the provision of lifestyle modification advice and/or the development of novel therapies.