Optical Coherence Tomography Testing Research Articles

Predictive value of macular ganglion cell-inner plexiform layer thickness in visual field defect of pituitary adenoma patients: a case-control study

The present study explored the association between preoperative macular ganglion cell-inner plexiform layer thickness (GCIPL) and retinal nerve fiber layer thickness (RNFL) measured by optical coherence tomography (OCT) and the recovery of visual field (VF) defect after surgery in pituitary adenoma patients. This case-control study included patients with pituitary adenoma in the Neurosurgery Department of Shanxi Provincial People's Hospital between October 2019 and June 2021. Cranial MRI examination, three-dimensional OCT, and VF testing (Humphrey Field Analyzer II750) were performed before and at 6months after the surgery. Fifty-three pituitary adenoma patients (81 eyes) were enrolled; 15 patients (23 eyes) were in the visual field did not recover group (VFNR), and 38 patients (58 eyes) were in the visual field recovered group (VFR). The temporal RNFL (P = 0.002) and average RNFL (P = 0.009) in the VFNR group were significantly lower than in the VFR group. The superior nasal GCIPL (P = 0.001), inferior nasal GCIPL (P = 0.001) and average GCIPL (P = 0.01) were significantly lower in the VFNR group than in the VFR group (all P < 0.01).The multivariable logistic regression analysis showed that nasal inferior GCIPL was an independent risk factor for VF recovery (odds ratio (OR) = 1.376,95% confidence interval (CI):1.089-1.739,P = 0.007). In the received operating characteristics (ROC) analysis, the area under the ROC curve (AUROCs) was the highest for nasal inferior GCIPL (AUROC = 0.739). In patients who underwent resection of pituitary adenoma, nasal inferior GCIPL was an independent risk factor of visual field defect recover after surgery.

Effect of Inconsistent Optical Coherence Tomography Scan Location on Glaucoma Progression Analysis.

Circumpapillary retinal nerve fiber layer (RNFL) thickness change induced by optical coherence tomography (OCT) scan circle location displacement was not completely compensated despite the use of Guided Progression Analysis (GPA), especially when the "R1" registration method was applied. The purpose of this study was to evaluate the effect of inconsistent OCT scan location on glaucoma progression detection using GPA. Eighty-four glaucomatous eyes with at least 4 serial OCT tests were included. To evaluate the ability of OCT GPA to adjust the OCT scan location, an analysis was performed without manipulation (control set), and after the OCT scan of the latest test was intentionally moved inferotemporally (test set). The eyes were classified into the adjustment and nonadjustment groups based on the superior or inferior quadrant RNFL thickness agreement between the control and test sets. When the OCT GPA parameters between the control and test sets were compared, the test set showed a greater superior RNFL thickness and lesser inferior RNFL thickness compared with the control set (P<0.05). The eyes in the nonadjustment group (n=21, 25%) had a lower chance of applying the eye-tracking function (P=0.003) and a higher frequency of the "R1" registration method of OCT GPA (P<0.001) than the adjustment group (n=63, 75%); all eyes with the "R1" method were in the nonadjustment group and all eyes with the "R2" method were in the adjustment group. Inconsistent OCT scan location induced changes in RNFL thickness that were not completely compensated despite the use of OCT GPA, especially when the "R1" registration method was applied. These findings indicates a potential for misidentified glaucoma progression.

Electrophysiological and psychophysical studies in assessment of visual functions in patients with hereditary optic neuropathy

To study the capabilities of electrophysiological and psychophysical examination methods for assessment of the functional state of ganglion cells, retina and optic nerve in patients with hereditary optic neuropathy (HON). The study included 60 patients (118 eyes) with a genetically confirmed diagnosis of HON. All study patients underwent visual field test (VFT), spectral optical coherence tomography (OCT), flash and pattern visual evoked potentials (VEP) (Flash-VEP, FVEP; Pattern-VEP, PVEP), photopic electroretinography with photonegative response (PhNR) registration and the color vision test. In 24 patients (46 eyes), these parameters were assessed before the start of treatment and one year later. The treatment involved the mitochondria-targeted antioxidant SkQ1 - plastoquinonyl-decyl-triphenylphosphonium bromide (PDTP) in the form of eye drops. The main PVEP components for 1.0° and 0.3° were registered in 20% and in 14% of patient eyes with HON and high visual functions, respectively. After one year of PDTP use, a significant decrease in P100 peak latency was found only in the group with disease duration of ≤1.5 years as of the time of treatment start (p<0.05). Significant differences were observed in the PhNR amplitude (p<0.004) between patients of the main and the control groups, as well as in the PhNR amplitude between patients with visual acuity of ≤0.1 and ≥0.13 (p<0.01). Patients with high visual functions were found to have a correlation between the PhNR amplitude, GCC thickness and the global loss index (GLV). Along with VFT, OCT and color vision tests, electrophysiological studies are one of the main methods of examining patients with HON. After one year of PDTP use, there was a significant decrease in the FVEP P2 peak latency in the group with a disease duration of ≤1.5 years as of the time of treatment start. The PhNR amplitude in patients with high visual functions was found to correlate with structural changes in the ganglion cell layer and the retinal nerve fiber layer.

Abstract 10310: Deep Learning for a Diagnosis of Plaque Erosion in Patients with Acute Coronary Syndromes

Background: The diagnosis of plaque erosion by optical coherence tomography (OCT) in patients with acute coronary syndromes (ACS) requires expertise in image interpretation. Objectives: This study sought to develop a deep learning (DL) algorithm that enables an accurate diagnosis of plaque erosion even for readers without experience in image interpretation. Methods: An image sequence transformer DL algorithm that mirrors the attention given by cardiologists to sequential images during a pull-back, was developed. The DL model was trained and internally validated for a diagnosis of plaque erosion both at the frame-level and at the patient-level in 581 ACS patients from 8 institutions in 4 countries. The model was externally tested in 292 ACS patients from an independent dataset. Training and validation dataset included 237,021 cross-sectional OCT images and testing dataset 65,394 cross-sectional OCT images. The OCT image classification performance was evaluated by area under the receiver-operating characteristic curve (AUC), and sensitivity and specificity. The results were compared against diagnoses made by OCT experts both at the frame-level and at the patient-level. Results: In the training and validation data set, 206 (43.2%) patients had plaque erosion, while in the external testing data set, 86 (29.5%) patients had plaque erosion. In the external testing data set, the DL model diagnosed plaque erosion with an AUC of 0.963 (95% CI, 0.962-0.963), a sensitivity of 89.9% (95% CI, 89.7-90.0), and a specificity of 91.1% (95% CI, 91.1-91.2) at the frame-level. At the patient-level, the DL model detected plaque erosion with an AUC of 0.901 (95% CI, 0.900-0.902), a sensitivity of 89.6% (95% CI, 89.4-89.8), and a specificity of 82.0% (95% CI, 81.9-82.2). Conclusion: A newly developed DL model enabled the accurate diagnosis of plaque erosion. This novel DL model will help cardiologists make an accurate diagnosis of plaque erosion in patients with ACS.

Incidence of non-glaucomatous ocular disease in patients with asymmetric optic disc cupping.

To evaluate the incidence of non-glaucomatous ocular disease in patients with asymmetric optic disc cupping. A retrospective case series, including consecutive patients with cup-to-disc ratio (CDR) asymmetry greater than 0.2. All patients underwent a complete neuro-ophthalmological examination, automated perimetry with the Humphrey 24-2 visual fields program. Retinal nerve fibre layer thickness was measured by optical coherence tomography (OCT). The results of neuroimaging, macular OCT and blood tests were recorded as well. Patients were assigned a diagnosis of glaucomatous optic neuropathy (GON) or non-glaucomatous disease (NGD). The main outcome measure was the rate of non-glaucomatous ocular disease. A total of 120 (67 males) patients with a mean age of 71.1 ± 12.5years met the inclusion criteria and were included in this study. The mean asymmetry in CDR between the eyes was 0.3 ± 0.13 (range, 0.2-0.9). Twenty patients (16.6%) had a visual field defect not typical for glaucoma and positive relative afferent pupillary defect was found in 24 patients (20%). Six patients were found to have newly diagnosed non-glaucomatous ocular disease: maculopathy in three patients, retinopathy in one patient and traumatic optic neuropathy in two patients. Patients with NGD were significantly younger than the patients with GON (59.8 ± 23.3 vs. 71.3 ± 11.5years, P = 0.001). Optic disc pallor was found in 4/93 patients with glaucoma compared to 3/6 with newly diagnosed non-glaucomatous disease (4.7% vs. 50.0%, P = 0.03). Asymmetric optic disc cupping can be associated with non-glaucomatous disease and may warrant neuro-ophthalmological evaluation, especially in younger patients or those with optic disc pallor.

Visual deficits and cognitive assessment of multiple sclerosis: confounder, correlate, or both?

The relationship between visual impairment and cognitive performance in multiple sclerosis (MS) remains poorly understood. To determine associations between visual acuity and optical coherence tomography (OCT) measures with cognitive performance of MS patients and healthy controls (HCs). 141 MS patients (with and without MS optic neuritis; MSON) and 50 HCs underwent neuropsychological, visual, and OCT testing. California Verbal Learning Test (CVLT-II), Brief Visuospatial Memory Test (BVMT-R), and Symbol Digit Modalities Test (SDMT) were used. Patients with test performance below -1.5 standard deviations of the mean HCs scores were labeled as cognitive impairment. Visual ability was assessed with 100%, 2.5%, and 1.25% low-contrast letter acuity (LCLA) charts. OCT-derived peripapillary retinal nerve fiber layer (pRNFL) thickness, macular volume (MV), macular ganglion cell inner plexiform (mGCIP) thickness (as a sum of GC and IP layers), and macular inner nuclear layer (mINL) were computed. 100% and 2.5% LCLA associated with SDMT in MS and HCs (p < 0.001; and p < 0.012, respectively). In MSON patients, visually demanding tests were explained by pRNFL and macular volume for SDMT (β = 0.172, p = 0.039 and β = 0.27, p = 0.001) and MV for BVMT-R (β = 0.21, p = 0.012). In non-MSON, only mINL was predictor of CVLT-II. pRNFL and MV predicted cognitive impairment with an accuracy of 72.2% (Negelkerke R2 = 0.234). These findings were driven by associations within the progressive MS subgroup. HC's SDMT performance was explained by mGCIP (β = 0.316, p = 0.001). Both LCLA and OCT-based measures (pRNFL and macular volume) were associated with MS cognitive performance. OCT-based measures were also significant predictors of cognitive status in MS patients. mGCIP associated with cognitive performance in HCs.

Visual Abnormalities Associate With Hippocampus in Mild Cognitive Impairment and Early Alzheimer's Disease.

Background and Objective: Alzheimer's disease (AD) has been shown to affect vision in human patients and animal models. This study was conducted to explore ocular abnormalities in the primary visual pathway and their relationship with hippocampal atrophy in patients with AD and mild cognitive impairment (MCI). The aim of this study was to investigate the potential value of ocular examinations as a biomarker during the AD progression.Methods: Patients with MCI (n = 23) or AD (n = 17) and age-matched cognitively normal controls (NC; n = 19) were enrolled. Pattern visual-evoked potentials (PVEP), flash electroretinogram (FERG) recordings and optical coherence tomography (OCT) were performed for all participants. Hippocampal volumes were measured by 3T magnetic resonance imaging. Cognitive function was assessed by Mini Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA) and Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog). Pearson correlation was employed to analyze the potential associations between ocular abnormalities and hippocampal volumes. Hierarchical regression models were conducted to determine associations between cognitive performances and ocular abnormalities as well as hippocampal volumes after adjusting for confounding factors including age, sex, cognitive reserve, and APOE4 status.Results: PVEP amplitude of P100 waveform was significantly decreased in AD patients compared to MCI and normal individuals. In FERG test, delayed latencies of rod response, rod cone response and 3.0 flicker time were found in cognitively impaired groups, indicating dysfunctions of both the rod and cone systems in the disease progression. OCT test revealed reduced macular retinal nerve fiber layer (m-RNFL) thickness in MCI and AD patients, which significantly correlated with brain structure of hippocampus particularly vulnerable during the progression of AD. Interestingly, P100 amplitude showed a significant association with hippocampal volumes even after adjusting confounding factors including age, sex, and cognitive reserve. Hierarchical regression analysis further demonstrated that m-RNFL thickness, as well as hippocampal volumes, significantly associated with ADAS-cog scores.Conclusion: P100 amplitude and m-RNFL thickness showed significant correlations with brain structure involved in AD-related neurodegeneration, and therefore proved to be potential indicators of brain imaging pathologies.

Factors Associated with Changes in Retinal Layers Following Acute Optic Neuritis: A Longitudinal Study Using Optical Coherence Tomography.

This study aimed to analyze longitudinal changes in retinal microstructures following acute optic neuritis and to identify the factors that affect those changes using spectral-domain optical coherence tomography (OCT). Forty-eight eyes of 37 patients with a first episode of optic neuritis and 48 eyes of 48 healthy controls were enrolled. Patients underwent serial OCT and visual function testing for more than six months. Individual layers from macular OCT were segmented with an automated algorithm. The total retinal layer (TRL), nerve fiber layer (NFL), ganglion cell layer (GCL) and inner plexiform layer (IPL) of optic neuritis eyes showed significant thinning with time over 6–15 months (p < 0.001 for all). The outer nuclear layer (ONL) showed a later decrease in thickness (p = 0.007). The outer retinal layer (ORL) showed an increase (p = 0.007) in thickness at two to five months which was sustained over time. Low visual acuity and neuromyelitis optica (NMO) immunoglobulin (Ig) G were associated with changes in the thickness of the GCL, IPL, and ONL over time (p < 0.05 for all). Low visual acuity was also associated with changes in the thickness of the NFL over time (p = 0.033). Dynamic changes of retinal microstructures varied according to the retinal layer examined after an optic neuritis attack. Initial visual acuity and NMO-IgG were found to be significant factors affecting the changes in thickness of each retinal layer. These results will lead to a better understanding of the pathologic changes that occur in eyes with optic neuritis.

Optical coherence tomography indices in the diagnosis and discrimination of stages of primary open-angle glaucoma in an African population.

The objective of this study was to determine the structure-function association of the optical coherence tomography (OCT) indices (retinal nerve fibre layer (RNFL), ganglion cell complex (GCC) and optic nerve head (ONH) parameters) with the visual field sensitivity and their diagnostic ability at different stages of primary open-angle glaucoma (POAG) among a population West-African descent. The study was a clinic-based prospective study which employed purposive sampling in the recruitment of clinically diagnosed POAG and non-glaucoma patients. OCT and visual field test (VFT) results were collated. Classification of the POAG cases was done using the Hodapp-Parrish-Anderson criteria. ROC was used for assessing the diagnostic ability of OCT indices. Pearson's correlation was used to assess the structure-function association. P value < 0.05 was considered statistically significant. Of the 497 subjects (497 eyes), 301 (60.6%) were males and 196 (39.4%) were females. The average, superior and inferior RNFL and GCC showed a strong positive correlation with the visual field sensitivity, but the average RNFL had the highest correlation (r = 0.673, p < 0.001). The parameters of the ONH showed a moderate-to-weak correlation with the visual field sensitivity. However, there was no significant correlation between structure and function in early POAG (p > 0.05). Superior GCC showed the highest diagnostic ability for POAG (AUC = 0.655; p < 0.001) comparable to the RNFL. Macula (GCC) and (RNFL) have a comparable ability to diagnose POAG at all the stages of POAG and can be used complimentarily for glaucoma assessment and diagnosis.

Relationship between monocyte/lymphocyte ratio and non-culprit plaque vulnerability in patients with acute coronary syndrome: An optical coherence tomography study.

The importance of monocyte/lymphocyte ratio (MLR) has been indicated in the initiation and progression of coronary artery disease. However, few previous researches demonstrated the relationship between MLR and plaque vulnerability. We aimed to investigate coronary non-culprit plaque vulnerability in patients with acute coronary syndrome (ACS) by optical coherence tomography (OCT).A total of 72 ACS patients who underwent coronary angiography and OCT test in Beijing Anzhen Hospital were included in this retrospective study. The plaque vulnerability and plaque morphology were assessed by OCT.The non-culprit plaque in high MLR group exhibited more vulnerable features, characterizing as thinner thickness of fibrous cap (P = .013), greater maximum lipid core angle (P = .010) and longer lipid plaque length (P = .041). A prominently negative liner relation was found between MLR and thickness of fibrous cap (R = –0.225, P = .005). Meanwhile, the proportion of OCT-detected thin cap fibro-atheroma (TCFA) (P = .014) and plaque rupture (P = .017) were higher in high MLR group. Most importantly, multivariable logistic regression analysis showed MLR level was identified as an independent contributor to the presence of TCFA (OR:3.316, 95%: 1.448–7.593, P = .005). MLR could differentiate TCFA with a sensitivity of 60.0% and a specificity of 85.1%.Circulating MLR level has potential value in identifying the presence of vulnerable plaque in patients with ACS. MLR, as a non- invasive biomarker of inflammation, may be valuable in revealing plaque vulnerability.

Effect of baseline test selection on glaucoma progression detection by optical coherence tomography-guided progression analysis

PurposeTo evaluate the effect of baseline test selection on progression detection of circumpapillary retinal nerve fibre layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) in glaucomatous eyes by optical...

Comparison of Rate of Change between Bruch's Membrane Opening Minimum Rim Width and Retinal Nerve Fiber Layer in Eyes Showing Optic Disc Hemorrhage

To investigate and compare the longitudinal rate of change of Bruch's membrane opening minimum rim width (BMO-MRW) and peripapillary retinal nerve fiber layer (RNFL) thickness in eyes showing optic disc hemorrhage(DH). Observational case series. A total of 82 subjects(82 eyes) showing DH who had undergone more than five reliable spectral-domain optical coherence tomography (OCT) tests were included. BMO-MRW and RNFL were measured with OCT at 3-month intervals. The rates of change in global and each Garway-Heath sector were calculated with a linear mixed-effects model after adjusting for age, sex, and BMO area. The mean follow-up period was 21.57 ± 7.88months with a mean number of 7.88 ± 2.39 OCT tests. Baseline demographics were age (58.37 ± 10.65 y); 46.3% were female; and the mean deviation was-4.41 ± 5.04 dB. The global rate of change in BMO-MRW was-3.507 ± 0.675μm/y and in-1.404 ± 0.208μm/y in RNFL. The rate of change was the greatest in the inferotemporal sector, which was-9.141 ± 1.254μm/y in BMO-MRW and-4.204 ± 0.490μm/y in the RNFL. The rate of change was significantly greater in BMO-MRW than in the RNFL in all sectors, except for the nasal sector (P < .05). Percentage of reduction was significantly greater in BMO-MRW than in RNFL in the inferotemporal and superotemporal sectors (P < .05). BMO-MRW showed a significantly greater rate of change than RNFL in eyes showing DH, especially in the inferotemporal and superotemporal sectors in percentage of reduction. Thus, it may be more advantageous to detect glaucomatous progression earlier in BMO-MRW than in the RNFL in eyes showing DH that are more likely to progress.

Correlation of Structural and Functional Changes in Ocular Hypertension and Early Glaucoma

Abstract Purpose To estimate the link between the thickness of retinal nerve fiber layer (RNFL); utilizing optical coherence tomography (OCT) and corresponding retinal sensitivity changes; utilizing visual field (VF) perimetry, in cases of ocular hypertension and early glaucoma. Methods Thirty patients (60 eyes) were gathered for this prospective, cross-sectional study. They were categorized into two groups. Group I comprised 30 eyes (15 patients) having ocular hypertension. Group II comprised 30 eyes (15 patients) early recognized as primary open angle glaucoma. Each patient underwent a thorough ophthalmologic examination, OCT for RNFL thickness estimation using quick RNFL thickness protocol and VF testing using automated perimetry (G2 program, central 30–2 threshold protocol). Pearson’s correlation was premediated between thickness of RNFL and VF indices. Results Significant connections between the thickness of temporal area of RNFL and mean sensitivity (MS), mean defect (MD) and loss of variance (LV) indices of VF (r = 0.533, -0.431, -0.388; P &amp;lt; 0.01, respectively) were noticed in patients having ocular hypertension. Additionally, a significant link between the thickness of the temporal area of RNFL and MS index of VF (0.441; P &amp;lt; 0.05) was noticed in patients with early POAG. Otherwise, there were no significant links between indices of VF and other areas of RNFL thickness in both groups. Conclusion Average RNFL thickness is certifiably not a dependable index for early determination of glaucoma or for the follow-up of ocular hypertension and POAG. Segmental RNFL thickness (especially temporal) appears to be a more dependable index. Profound structural modification with OCT test comprises an imperative sign of early utilitarian changes, regardless of whether they are not yet recognized with perimetry. The MS index of VF is by all accounts sensitive for the follow-up of ocular hypertension.

CHANGES IN GANGLION CELL AND INNER PLEXIFORM LAYERS THICKNESS AND RETINAL MICROVASCULATURE IN DIFFERENT STAGES OF GLAUCOMA

Background: Primary open angle glaucoma (POAG) is an optic neuropathy characterized by progressive degeneration of retinal ganglion cells (RGC) and their axons, which results in characteristic excavation of the neuroretinal rim with corresponding visual field (VF) deficits. Optical coherence tomography angiography (OCTA) is a novel imaging modality that can detect vascular flow of the retina and choroid in great detail. The ability to segment OCT angiograms into the different vascular layers may improve understanding of disease pathogenesis. Objective: To evaluate the correlation between Ganglion Cell and Inner Plexiform Layers thickness using optical coherence tomography (OCT) and the macular microvasculature density in different stages of primary open angle glaucoma using optical coherence tomography angiography (OCTA). Subjects and Methods: The study was performed on 80 eyes of 48 subjects including 20 eyes of 11 controls, and 60 eyes of 37 POAG cases which were divided into 3 groups according to Hodapp,Parish,Anderson (H-P-A) classification; Group1: mild glaucoma (20 eyes), Group 2: moderate glaucoma (20 eyes),Group 3: severe glaucoma (20 eyes). Results: In our study, we found that there was a significant reduction in Ganglion Cell - Inner Plexiform Layer (GCIPL) thickness and macular VD in patients with POAG which increased with increasing glaucoma severity, also we found that OCT and OCTA parametrs were significantly differentiate between normal and POAG cases and also between different stages of POAG. Also we found that an OCTA was an important diagnostic tool in diagnosing mild cases of POAG and to differentiate between mild and moderate cases of POAG,in contrast to OCT in which there was no significant differance between mild and moderate cases of POAG. OCTA seems to be a good candidate for diagnosis and follow-up of glaucoma, complementing the results provided by OCT and visual field testing. Conclusion: Significant differences between eyes with POAG and normal eyes in terms of the macular GCIPL thickness and microvasculature density (VD) suggest that the macular GCIPL thickness and the retinal capillary vessel area density may be reliable indicators of glaucoma severity.

CHANGES IN GANGLION CELL AND INNER PLEXIFORM LAYERS THICKNESS AND RETINAL MICROVASCULATURE IN DIFFERENT STAGES OF GLAUCOMA

Background: Primary open angle glaucoma (POAG) is an optic neuropathy characterized by progressive degeneration of retinal ganglion cells (RGC) and their axons, which results in characteristic excavation of the neuroretinal rim with corresponding visual field (VF) deficits. Optical coherence tomography angiography (OCTA) is a novel imaging modality that can detect vascular flow of the retina and choroid in great detail. The ability to segment OCT angiograms into the different vascular layers may improve understanding of disease pathogenesis. Objective: To evaluate the correlation between Ganglion Cell and Inner Plexiform Layers thickness using optical coherence tomography (OCT) and the macular microvasculature density in different stages of primary open angle glaucoma using optical coherence tomography angiography (OCTA). Subjects and Methods: The study was performed on 80 eyes of 48 subjects including 20 eyes of 11 controls, and 60 eyes of 37 POAG cases which were divided into 3 groups according to Hodapp,Parish,Anderson (H-P-A) classification; Group1: mild glaucoma (20 eyes), Group 2: moderate glaucoma (20 eyes),Group 3: severe glaucoma (20 eyes). Results: In our study, we found that there was a significant reduction in Ganglion Cell - Inner Plexiform Layer (GCIPL) thickness and macular VD in patients with POAG which increased with increasing glaucoma severity, also we found that OCT and OCTA parametrs were significantly differentiate between normal and POAG cases and also between different stages of POAG. Also we found that an OCTA was an important diagnostic tool in diagnosing mild cases of POAG and to differentiate between mild and moderate cases of POAG,in contrast to OCT in which there was no significant differance between mild and moderate cases of POAG. OCTA seems to be a good candidate for diagnosis and follow-up of glaucoma, complementing the results provided by OCT and visual field testing. Conclusion: Significant differences between eyes with POAG and normal eyes in terms of the macular GCIPL thickness and microvasculature density (VD) suggest that the macular GCIPL thickness and the retinal capillary vessel area density may be reliable indicators of glaucoma severity.

Optical Coherence Tomography in Knobloch Syndrome.

Knobloch syndrome is a genetic disorder defined by occipital defect, high myopia, and vitreoretinal degeneration. The authors studied retinal changes in patients with Knobloch syndrome using optical coherence tomography (OCT). The authors report patients with Knobloch syndrome who received OCT testing during their care from 2011 to 2016. Diagnosis was based on high myopia, characteristic fundus, and occipital scalp or skull abnormalities with/without featureless irides and/or ectopia lentis. When available, diagnosis was confirmed by the detection of COL18A1 mutations. The authors studied eight eyes from five patients. Two eyes were excluded due to chronic retinal detachment. OCT findings included epiretinal membrane, peripapillary vitreoretinal traction with retinoschisis, absent or rudimentary foveal pits, mean macular thickness of 113.4 μm, poor lamination, retinal pigment epithelium (RPE) atrophy, photoreceptor depletion, and mean choroidal thickness of 168.5 μm with enlarged choroidal vessels. OCT findings in Knobloch syndrome include abnormal vitreoretinal traction, poor foveal differentiation, poor retinal lamination, retinal thinning, RPE attenuation, myopic choroidal thinning, and pachychoroid. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e203-e210.].

Early hydroxychloroquine retinopathy: optical coherence tomography abnormalities preceding Humphrey visual field defects

Background/AimsHydroxychloroquine (HCQ) retinopathy may result in severe and irreversible vision loss, emphasising the importance of screening and early detection. The purpose of this study is to report the novel finding...

Visual system involvement in Alzheimer’s disease

To assess in Alzheimer’s disease (AD) patients the Visual System functioning through full field Visual Evoked Potentials (VEPs) and to measure neuro-retinal thickness through Optical Coherence Tomography (OCT), in particular the peripapillary Retinal Nerve Fiber Layer (RNFL) thickness and macular Ganglion and Inner Plexiform Layers (GCL and IPL) volume, in order to find new reproducible diagnostic markers and outcome measures. 145 subjects were enrolled (49 with AD, 39 with Mild Cognitive Impairment (MCI) and 57 controls, HC), receiving an OCT scan acquisition and Visual Evoked Potentials (VEPs) in 36 AD, 25 MCI and 39 HC at baseline. Nineteen AD and 23 MCI underwent a follow up OCT scan. At baseline peripapillary RNFL, global and in superior quadrant, was significantly thinner in AD and MCI patients than in HC. Macular GCL was significantly thinner in AD than in MCI and HC. A positive association was found between OCT and neuropsychological tests. Over time AD patients showed a significantly higher decay in RNFL thickness than MCI subjects. Furthermore, RNFL, GCL and IPL thinning seemed to be associated with worsening in cognition. Our findings confirm that the Visual System is involved in AD and OCT is as a possible marker of disease severity.

Automated algorithms combining structure and function outperform general ophthalmologists in diagnosing glaucoma.

PurposeTo test the ability of machine learning classifiers (MLCs) using optical coherence tomography (OCT) and standard automated perimetry (SAP) parameters to discriminate between healthy and glaucomatous individuals, and to compare it to the diagnostic ability of the combined structure-function index (CSFI), general ophthalmologists and glaucoma specialists.DesignCross-sectional prospective study.MethodsFifty eight eyes of 58 patients with early to moderate glaucoma (median value of the mean deviation = −3.44 dB; interquartile range, -6.0 to -2.4 dB) and 66 eyes of 66 healthy individuals underwent OCT and SAP tests. The diagnostic accuracy (area under the ROC curve—AUC) of 10 MLCs was compared to those obtained with the CSFI, 3 general ophthalmologists and 3 glaucoma specialists exposed to the same OCT and SAP data.ResultsThe AUCs obtained with MLCs ranged from 0.805 (Classification Tree) to 0.931 (Radial Basis Function Network, RBF). The sensitivity at 90% specificity ranged from 51.6% (Classification Tree) to 82.8% (Bagging, Multilayer Perceptron and Support Vector Machine Gaussian). The CSFI had a sensitivity of 79.3% at 90% specificity, and the highest AUC (0.948). General ophthalmologists and glaucoma specialists’ grading had sensitivities of 66.2% and 83.8% at 90% specificity, and AUCs of 0.879 and 0.921, respectively. RBF (the best MLC), the CSFI, and glaucoma specialists showed significantly higher AUCs than that obtained by general ophthalmologists (P<0.05). However, there were no significant differences between the AUCs obtained by RBF, the CSFI, and glaucoma specialists (P>0.25).ConclusionOur findings suggest that both MLCs and the CSFI can be helpful in clinical practice and effectively improve glaucoma diagnosis in the primary eye care setting, when there is no glaucoma specialist available.

Four Questions for Every Clinician Diagnosing and Monitoring Glaucoma.

We pose 4 questions for the clinician diagnosing and monitoring glaucoma, and supply evidence-based answers. The first question is: "When do you perform a 10-2 (2-degree grid) visual field (VF) test?" We argue the best answer is: anyone you would do, or have done, a 24-2 (6-degree grid) VF on should have both a 24-2 and a 10-2 VF within the first 2 visits. Second, "When do you perform an optical coherence tomography (OCT) scan of the macula?" We argue that, if you are performing an OCT test, then it should include both the macula and disc, either as a single scan or as 2 scans, one centered on the macula and the other on the disc. Third, "How do you know if the VF and OCT tests agree?" The poor answer is, "I use summary statistics such as 24-2 mean deviation and global or quadrant average of retinal nerve fiber layer (RNFL) thickness." It is much better to topographically compare abnormal regions on the OCT to abnormal regions on the VF. Finally, the fourth question is: "When do you look at OCT images?" We argue that, at a minimum, the clinician should be directly examining an image of the circumpapillary RNFL, and this image should be sufficiently large and with sufficient resolution so that local damage can be seen, and the segmentation evaluated.