Nerve Fiber Layer Thickness Measurements Research Articles

Enhancing the structure–function relationship in glaucoma using anatomical compensation of retinal nerve fibre layer

Background/aimsTo investigate whether compensating retinal nerve fibre layer (RNFL) thickness measurements for demographic and anatomical ocular factors can strengthen the structure–function relationship in patients with glaucoma.Methods600 eyes from 412 patients...

Anatomical Features can Affect OCT Measures Used for Clinical Decisions and Clinical Trial Endpoints.

To understand the association between anatomical parameters of healthy eyes and optical coherence tomography (OCT) circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements. OCT cpRNFL thickness was obtained from 396 healthy eyes in a commercial reference database (RDB). The temporal quadrant (TQ), superior quadrant (SQ), inferior quadrant (IQ), and global (G) cpRNFL thicknesses were analyzed. The commercial OCT devices code these values based on percentiles (red, <1%; yellow, ≥1% and <5%), after taking age and disc area into consideration. Four anatomical parameters were assessed: fovea-to-disc distance, an estimate of axial length, and the locations of the superior and the inferior peaks of the cpRNFL thickness curve. Pearson correlation values were obtained for the parameters and the thickness measures of each of the four cpRNFL regions, and t-tests were performed between the cpRNFL thicknesses coded as abnormal (red or yellow, <5%) versus normal (≥5%). For each of the four anatomical parameters, the correlation with the thickness of one or more of the TQ, SQ, IQ, and G regions exceeded the correlation with age or disc area. All four parameters were significantly (P < 0.001) associated with the abnormal cpRNFL values. The significant parameters were not the same for the different regions; for example, a parameter could be negatively correlated for the TQ but positively correlated with the SQ or IQ. In addition to age and disc area, which are used for inferences in normative databases, four anatomical parameters are associated with cpRNFL thickness. Taking these additional anatomical parameters into consideration should aid diagnostic accuracy.

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.

Assessment of linear regression of peripapillary optical coherence tomography retinal nerve fiber layer measurements to forecast glacuoma trajectory.

Linear regression of optical coherence tomography measurements of peripapillary retinal nerve fiber layer thickness is often used to detect glaucoma progression and forecast future disease course. However, current measurement frequencies suggest that clinicians often apply linear regression to a relatively small number of measurements (e.g., less than a handful). In this study, we estimate the accuracy of linear regression in predicting the next reliable measurement of average retinal nerve fiber layer thickness using Zeiss Cirrus optical coherence tomography measurements of average retinal nerve fiber layer thickness from a sample of 6,471 eyes with glaucoma or glaucoma-suspect status. Linear regression is compared to two null models: no glaucoma worsening, and worsening due to aging. Linear regression on the first M ≥ 2 measurements was significantly worse at predicting a reliable M+1st measurement for 2 ≤ M ≤ 6. This range was reduced to 2 ≤ M ≤ 5 when retinal nerve fiber layer thickness measurements were first "corrected" for scan quality. Simulations based on measurement frequencies in our sample-on average 393 ± 190 days between consecutive measurements-show that linear regression outperforms both null models when M ≥ 5 and the goal is to forecast moderate (75th percentile) worsening, and when M ≥ 3 for rapid (90th percentile) worsening. If linear regression is used to assess disease trajectory with a small number of measurements over short time periods (e.g., 1-2 years), as is often the case in clinical practice, the number of optical coherence tomography examinations needs to be increased.

Long-term variability of retinal nerve fibre layer thickness measurement in patients with glaucoma of African and European descents

BackgroundTo examine long-term retinal nerve fibre layer thickness (RNFLT) variability and associated clinical factors in African (AD) and European descent (ED) individuals with glaucoma.MethodsThis retrospective cohort study included glaucoma eyes...

Effect of Repeated Intravitreal Injections in Glaucoma Spectrum Diseases.

To evaluate whether repeated intravitreal injections (IVI) with an anti-vascular endothelial growth factor (anti-VEGF) agent are associated with glaucomatous progression in eyes with glaucoma spectrum diseases (GSD). Single-center, retrospective, longitudinal study of patients with bilateral and similar GSD who: (1) received ≥8 IVI in only one eye during the study period; (2) had ≥2 retinal nerve fiber layer thickness (RNFL) measurements obtained by spectral-domain optical coherence tomography (SD-OCT) at least 12 months apart. The primary outcome was the absolute RNFL thickness change, comparing injected and fellow uninjected eyes. Linear mixed effects models were constructed, including a multivariable model. Sixty-eight eyes from 34 patients were included, 34 injected and 34 fellow uninjected eyes. Average baseline age was 67.68±21.77 years with a follow-up of 3.66±1.89 years and 25.12±14.49 IVI. RNFL thickness decreased significantly from 80.92±15.78 to 77.20±17.35 μm (p<0.001; -1.18±1.93 μm/year) in injected eyes and from 79.95±17.91 to 76.61±17.97 μm (p<0.001; -1.07±0.98 μm/year) in uninjected eyes. In a multivariable linear mixed model of injected eyes, only higher baseline RNFL thickness (p < 0.001) significantly predicted higher absolute RNFL thickness loss. Neither absolute RNFL thickness variation (p=0.716) nor RNFL rate (p=0.779) was significantly different between paired injected and uninjected eyes. Absolute IOP variation was not significantly different between groups (16.62±4.77 to 15.09±4.34 mmHg in injected eyes and 17.68±5.01 to 14.50±3.39 mmHg in fellow uninjected eyes; p=0.248). The proportion of eyes receiving glaucoma medical treatment increased significantly in both groups (55.9% to 76.5% in injected eyes; p=0.039; 58.8% to 76.5% in uninjected eyes; p = 0.031). The number of glaucoma medications also increased significantly in both groups (1.03±1.11 to 1.59±1.18 glaucoma medications in injected eyes; p=0.003; 1.09±1.11 to 1.56±1.19 glaucoma medications in uninjected eyes; p=0.003). Repeated IVI do not seem to accelerate glaucomatous progression. Future studies with a longer follow-up are needed.

The diagnostic accuracy of photopic negative responses evoked by broadband and chromatic stimuli in a clinically heterogeneous population

PurposeTo compare the diagnostic accuracy of the photopic negative response (PhNR) elicited by red-blue (RB) and white-white (WW) stimuli, for detection of retinal ganglion cell (RGC) dysfunction in a heterogeneous clinical cohort.MethodsAdults referred for electrophysiological investigations were recruited consecutively for this single-centre, prospective, paired diagnostic accuracy study. PhNRs were recorded to red flashes (1.5 cd·s·m−2) on a blue background (10 cd·m−2) and to white flashes on a white background (the latter being the ISCEV standard LA 3 stimulus). PhNR results were compared with a reference test battery assessing RGC/optic nerve structure and function including optical coherence tomography (OCT) retinal nerve fibre layer thickness and mean RGC volume measurements, fundus photography, pattern electroretinography and visual evoked potentials. Primary outcome measures were differences in sensitivity and specificity of the two PhNR methods.ResultsTwo hundred and forty-three participants were initially enrolled, with 200 (median age 54; range 18–95; female 65%) meeting inclusion criteria. Sensitivity was 53% (95% confidence intervals [CI] 39% to 68%) and 62% (95% CI 48% to 76%), for WW and RB PhNRs, respectively. Specificity was 80% (95% CI 74% to 86%) and 78% (95% CI 72% to 85%), respectively. There was a statistically significant difference between sensitivities (p = 0.046) but not specificities (p = 0.08) of the two methods. Receiver operator characteristic (ROC) area under the curve (AUC) values were 0.73 for WW and 0.74 for RB PhNRs.ConclusionPhNRs to red flashes on a blue background may be more sensitive than white-on-white stimuli, but there is no significant difference between specificities. This study highlights the value and potential convenience of using white-on-white stimuli, already used widely for routine ERG assessment.

Normative Percentiles of Retinal Nerve Fiber Layer Thickness and Glaucomatous Visual Field Loss.

Circumpapillary retinal nerve fiber layer thickness (RNFLT) measurement aids in the clinical diagnosis of glaucoma. Spectral domain optical coherence tomography (SD-OCT) machines measure RNFLT and provide normative color-coded plots. In this retrospective study, we investigate whether normative percentiles of RNFLT (pRNFLT) from Spectralis SD-OCT improve prediction of glaucomatous visual field loss over raw RNFLT. A longitudinal database containing OCT scans and visual fields from Massachusetts Eye & Ear glaucoma clinic patients was generated. Reliable OCT-visual field pairs were selected. Spectralis OCT normative distributions were extracted from machine printouts. Supervised machine learning models compared predictive performance between pRNFLT and raw RNFLT inputs. Regional structure-function associations were assessed with univariate regression to predict mean deviation (MD). Multivariable classification predicted MD, pattern standard deviation, MD change per year, and glaucoma hemifield test. There were 3016 OCT-visual field pairs that met the reliability criteria. Spectralis norms were found to be independent of age, sex, and ocular magnification. Regional analysis showed significant decrease in R2 from pRNFLT models compared to raw RNFLT models in inferotemporal sectors, across multiple regressors. In multivariable classification, there were no significant improvements in area under the curve of receiver operating characteristic curve (ROC-AUC) score with pRNFLT models compared to raw RNFLT models. Our results challenge the assumption that normative percentiles from OCT machines improve prediction of glaucomatous visual field loss. Raw RNFLT alone shows strong prediction, with no models presenting improvement by the manufacturer norms. This may result from insufficient patient stratification in tested norms. Understanding correlation of normative databases to visual function may improve clinical interpretation of OCT data.

Evaluation of retinal thickness measured by optical coherence tomography in patients with generalized anxiety disorder

PurposeTo compare the peripapillary retinal nerve fiber layer thickness, macular thickness, ganglion cell layer thickness, and inner plexiform layer thickness determined by Optic Coherence Tomography in the patient group diagnosed with a generalized anxiety disorder who did not receive any psychiatric medication with the healthy control group. MethodsForty newly diagnosed, drug-free Generalized Anxiety Disorder patients and 43 healthy age- and gender-matched control subjects were included in the study. Macular thickness, ganglion cell layer thickness, inner plexiform layer thickness, and peripapillary retinal nerve fiber layer thickness were measured using optical coherence tomography. Structured Clinical Interviews and a State-Trait Anxiety Scale were applied to both groups. ResultsGender distributions (P = 0.965) and mean ages were similar between the groups (P = 0.340). Retinal nerve fiber layer thickness measurements were not significantly different between the groups. We observed statistically significant thinning in the inner superior, inner nasal, inner temporal, inner inferior, and outer inferior quadrants of the macula in the patient group compared to the control group (P = 0.046, P = 0.046, P = 0.020, P = 0.007, P = 0.014). We found thinning at the Ganglion cell layer in the inner inferior and outer temporal quadrants (Respectively P = 0.018, P = 0.049), inner plexiform layer in the inner nasal, inner temporal, and inner inferior quadrants (Respectively P = 0.046, P = 0.044, P = 0.011) compared to the control group. ConclusionsThis is the first study to reveal thinning in the macula, ganglion cell layer, and inner plexiform layer in newly diagnosed, drug-free Generalized Anxiety Disorder patients compared to the control group.

An Artificial Intelligence Enabled System for Retinal Nerve Fiber Layer Thickness Damage Severity Staging

To develop an objective glaucoma damage severity classification system based on OCT-derived retinal nerve fiber layer (RNFL) thickness measurements. Algorithm development for RNFL damage severity classification based on multicenter OCT data. A total of 6561 circumpapillary RNFL profiles from 2269 eyes of 1171 subjects to develop models, and 2505 RNFL profiles from 1099 eyes of 900 subjects to validate models. We developed an unsupervised k-means model to identify clusters of eyes with similar RNFL thickness profiles. We annotated the clusters based on their respective global RNFL thickness. We computed the optimal global RNFL thickness thresholds that discriminated different severity levels based on Bayes' minimum error principle. We validated the proposed pipeline based on an independent validation dataset with 2505 RNFL profiles from 1099 eyes of 900 subjects. Accuracy, area under the receiver operating characteristic curve, and confusion matrix. The k-means clustering discovered 4 clusters with 1382, 1613, 1727, and 1839 samples with mean (standard deviation) global RNFL thickness of 58.3 (8.9) μm, 78.9 (6.7) μm, 87.7 (8.2) μm, and 101.5 (7.9) μm. The Bayes' minimum error classifier identified optimal global RNFL values of > 95 , 86 to 95 , 70 to 85 and < 70 for discriminating normal eyes and eyes at the early, moderate, and advanced stages of RNFL thickness loss, respectively. About 4% of normal eyes and 98% of eyes with advanced RNFL loss had either global, or ≥ 1 quadrant, RNFL thickness outside of normal limits provided by the OCT instrument. Unsupervised machine learning discovered that the optimal RNFL thresholds for separating normal eyes and eyes with early, moderate, and advanced RNFL loss were 95 , 85 μm, and 70 , respectively. This RNFL loss classification system is unbiased as there was no preassumption or human expert intervention in the development process. Additionally, it is objective, easy to use, and consistent, which may augment glaucoma research and day-to-day clinical practice. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Höffding step and beyond: The impact of visual sensory impairment on cognitive performance in neuropsychological testing of survivors of acute methanol poisoning.

Sensory deficits can result in limitations regarding how well neuropsychological test findings can be interpreted. Only a few studies have investigated the influence of vision alteration on neuropsychological tests. In 2012 the Czech Republic experienced mass methanol poisoning. Methanol metabolites cause histotoxic hypoxia to the optic nerve. In the current study, the effect of the toxic damage on the parts of the visual pathway on visual and non-visual neuropsychological measures was investigated using electrophysiological methods (visual evoked potential (VEP) and optical coherence tomography (OCT) with retinal nerve fibre layer (RNFL) thickness measurement. 53 individuals who experienced methanol poisoning participated in this research (76% men; ages 24 to 74 years, mean = 43.8±14.6 years; education 11.9±1.4 years). Each participant underwent comprehensive neurological, ophthalmological, and neuropsychological examinations. The results of mixed-effect models revealed significant small to a medium association between the Stroop test weak interference and Grooved Pegboard with the left eye global, nasal and temporal RNFL thickness. Also, medium associations between the Finger Tapping test and the Stroop test weak interference and left eye temporal RNFL, right eye temporal RNFL, and the latency P1 of VEP in the left eye were significant. The results of this study found a small to medium association (r = .15- .33; p = .010- .046) between RNFL thickness and cognitive visual test performance. Careful interpretation is suggested regarding results obtained from visual tests of the executive or motor functioning with participants with RNFL decrease or other types of early visual processing damage.

Evaluation of ganglion cell complex and retinal nerve fiber layer thinning in epilepsy patients.

This study aimed to compare the perimacular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (RNFL) thickness measurements of epileptic and healthy individuals. The right eyes of 38 epileptic and 38 healthy individuals who had been using antiepileptic drugs (AEDs) for at least 1 year were included in the study. Central macular thickness, perimacular GCC thickness and volume, and peripapillary retinal nerve fiber layers were measured by optical coherence tomography (OCT) device. Perimacular 1, 3, and 6 mm circle diameters of Early Treatment of Diabetic Retinopathy Study (ETDRS. were selected for GCC measurements. In epilepsy patients, GCC was significantly lower in the 3 mm superior quadrant and 6 mm in all quadrants compared to the control group (P < 0.05). RNFL was significantly thinner in epilepsy patients only in the temporal-inferior quadrant (P < 0.05). There was no significant difference between the patients who received AEDs as monotherapy and polytherapy (P > 0.05). We found that epilepsy patients had significant thinning in the GCC layers and temporal-inferior quadrant of RNFL compared to the control group. Our findings from the study show that early retinal changes in epilepsy patients, especially perimacular GCC layers, can be followed up with OCT.

Ocular axial length influence on peripapillary retinal nerve fiber layer thickness measurement with optical coherence tomography

BackgroundOptical coherence tomography (OCT) allows the measurement of the peripapillary optic nerve fiber layer (RNFL) thickness. The effect of ocular axial length (AL) on RNFL thickness measurement may be relevant in the interpretation of OCT results in diagnosing optic nerve diseases. PurposeTo assess the influence of ocular AL on RNFL thickness and on optic disc topographic parameters (optic disc area, rim area and cup volume) measured by OCT, in healthy individuals. MethodsA sample of 109 healthy eyes classified into 3 groups according to AL (A: AL<22mm; B: AL 22−24.5mm; C: AL>24.5mm) was studied. RNFL thickness and optic disc topographic parameters were measured using Swept-Source OCT Triton (Topcon) and were compared between groups using a variance analysis. Correlation between the AL and the study variables was performed using a Pearson's correlation coefficient test. ResultsThe RNFL thickness was lower in eyes with higher AL in the superior (r=−0.41; p<0.001), inferior (r=0.58; p<0.001) and nasal (r=−0.43; p<0.001) quadrants, in the mean value of the RNFL (r=−0.49; p<0.001), optic disc area (r=−0.40; p<0.001) and rim area (r=−0.25; p=0.01). ConclusionsAL is negatively correlated with RNFL thickness and optic disc topographic parameters measured by Swept-Source OCT Triton (Topcon).

Risk factors for structural and functional progression of primary open-angle glaucoma in an African ancestry cohort

Background/aimsTo investigate the rates of structural and functional progression of primary open-angle glaucoma in an African ancestry cohort and identify risk factors for progression.MethodsThis retrospective study included 1424 eyes from...

Reproducibility of Retinal Nerve Fiber Layer and Macular Thickness Measurement by Spectral Domain Optical Coherence Tomography

Purpose: To assess the reproducibility of retinal nerve fiber layer (RNFL) and macular thickness by spectral domain optical coherence tomography (SD-OCT) when the same investigator does scan thrice in a span of one hour without reference to the previous scan, is able to get similar results or not, without using the repeat function.Methods. In this prospective observational study 200 subjects who fulfilled the inclusion &amp; exclusion criteria were scanned 3 times as per pre-defined guidelines at 0 minutes, 30 minutes; 60 minutes on the same day, by the same investigator using SD-OCT for measurements of RNFL and macular thickness &amp; observations were statistically analyzed &amp; correlated.Results. In RNFL thickness, temporal sector shows the worst reproducibility as compared to other sectors. The RNFL thickness was greatest in superior quadrant and thinnest in temporal quadrant. Female values were significantly higher than males in RNFL superior and RNFL symmetry. For macular thickness, temporal sector (mid-zone) showed the worst reproducibility and in outer-zone, Inferior sector showed the worst reproducibility. It also shows that macular thickness was thinnest at the central zone (innermost 1 mm ring), thickest within the inner 3 mm ring and diminished peripherally.Conclusion. RNFL and macular thickness measurements by SD-OCT by the same observer at 0 minutes, 30 minutes and 60 minutes were very reproducible except in the sectors specifically mentioned. The greater the thickness of RNFL in any sector, the better will be the reproducibility in that sector. For macular thickness, temporal sector (mid-zone) showed the worst reproducibility &amp; with an increase in age the macular thickness measurements decreases.

Usability of Real-Time Elastography for the Diagnosis of Primary Open Angle and Pseudoexfoliation Glaucoma.

This study aims to investigate real-time elastography (RTE) use in the evaluation of the optic nerve head (ONH) and peripapillary structures for the diagnosis of primary open angle (POAG) and pseudoexfoliation (PEX) glaucoma. This case-controlled study included 30 patients with POAG, 30 patients with PEX glaucoma, and 30 age-matched control subjects. All of the participants underwent comprehensive ophthalmological examinations covering vessel density of optic nerve and retinal nerve fiber layer (RNFL) thickness measurements with optical cohorence tomography angiography and mean deviation (MD) measurements with Humphrey II Perimetry Visual Field Analyzer. In vivo evaluation of the biomechanical properties of the ONH and peripapillary structures were performed with RTE in all participants. We observed higher ratios of orbital fat to optic nerve head (ROFON) values (P=.008) and strain ratios of orbital fat to scleral-choroidal-retinal complex (ROFSCR) values (P=.004) in the POAG group compared with PEX glaucoma group and higher ROFON (P=.012) and ROFSCR values (P=.004) in PEX glaucoma group than the control group. ROFON and ROFSCR values were positively correlated with glaucoma duration and negatively correlated with MD, radial peripapillary vessel density (RPCVD), and inside disc vessel density in both glaucoma groups (P < .005; only in the PEX glaucoma group for MD and ROFSCR, P=.445). Determining the biomechanical properties of ONH and peripapillary structures with RTE in glaucomatous eyes may offer a new perspective on the diagnosis and follow-up of the progression of the disease.

Minimum Rim Width and Peripapillary Retinal Nerve Fiber Layer Thickness for Diagnosing Early to Moderate Glaucoma.

In a cross-sectional study from a Brazilian multiracial population, minimum rim width (MRW) and peripapillary retinal nerve fiber layer thickness measurements from OCT showed comparable diagnostic performance in discriminating early to moderate glaucoma from healthy eyes. The purpose of this study is to compare the ability of MRW and peripapillary retinal nerve fiber layer thickness (RNFLT) measurements in discriminating early to moderate glaucoma from healthy eyes in a Brazilian population. A total of 155 healthy controls and 118 patients with mild to moderate glaucoma (mean deviation >-12 dB) underwent MRW and RNFLT measurements with optical coherence tomography. Only 1 eye per patient was included in the analysis. A receiver operating characteristic (ROC) regression model was used to evaluate the diagnostic accuracy of MRW and RNFLT, whereas adjusting for age and Bruch membrane opening area. Sensitivities at fixed specificities of 95% were calculated for each parameter. Global RNFLT and MRW showed comparable area under the ROC curves [0.93 (0.91-0.96) and 0.93 (0.89-0.96), respectively; P =0.973]. Both parameters had similar sensitivities (75% vs. 74%, respectively; P =0.852) at a fixed specificity of 95%. The best sector for diagnosing glaucoma for both parameters was the temporal inferior sector, which showed an area under the ROC curve of 0.93 (0.87-0.96) for RNFLT and 0.91 (0.86-0.95) for MRW ( P =0.320). The temporal inferior sector showed similar sensitivities for RNFLT and MRW measurements (83% vs. 77%, respectively) at a fixed specificity of 95% (P =0.230). MRW and RNFLT measurements showed comparable diagnostic performance in discriminating early to moderate glaucoma from healthy eyes in a Brazilian multiracial population.

Retrograde Optic Nerve Degeneration in Pituitary Adenoma: A Study with RE-PERG.

RE-PERG is altered in presence of primary neuronal degeneration of retinal ganglion cells, both in glaucoma and other diseases. A previous study showed that in a model of retrograde degeneration (vascular dementia) RE-PERG was normal. In this study, we enrolled patients with pituitary adenoma (PA) to evaluate RE-PERG findings in another model of retrograde degeneration compared with healthy controls (HC). Based on the outcome of the present and our previous studies with RE-PERG, and reviewing the literature, we discuss the physiopathology of glaucoma. Twelve PA patients and 14 age-matched HC were recruited. All participants performed visual field (VF) test, retinal nerve fiber layer (RNFL) and ganglion cells complex (GCC) thickness measurement by means of optical coherence tomography (OCT), visual evoked potentials (VEPs) and RE-PERG, a non-invasive, fast steady-state pattern electroretinogram (SS-PERG) sampled in five consecutive blocks of 130 events. VEPs amplitude was significantly lower in PA with respect to HC (6.8±0.6 vs 7.4±0.6 µV; p=0.045). VEPs latency was higher in PA (123.2±5.8 vs 103.6±4.1 msec; p<0.01). As for VF, mean defect (MD) and pattern standard deviation (PSD) were higher in PA (-6.6±2.6 vs -0.01±1.02 dB; p<0.01 and 8.5±3.1 vs 1.5±0.3; p<0.01, respectively). RNFL thickness was lower in PA (88±8.1 vs 97±9.3 µ; p=0.01). There was no statistically significant difference between PA and HC for RE-PERG. There was a significant correlation among MD, PSD, VEPs amplitude, PERG amplitude and RNFL thickness in the PA group, whereas no correlation was found with SDPh, which remains as normal as in the HC group. Our findings confirm that RE-PERG is not altered in retrograde degeneration. Based on the outcome of the present and our previous studies about RE-PERG and glaucoma, we assume that in glaucoma a double mechanism of retinal ganglion cells degeneration, both retrograde and primary, can coexist.

Optical coherence tomography changes in ankylosing spondylitis patients on long-term adalimumab treatment.

Long-term ocular effects of tumor necrosis factor-alpha inhibitors remain to be elucidated. This study aimed to examine the long-term effects of adalimumab use on neural tissue of the anterior visual pathways using optical coherence tomography in patients with ankylosing spondylitis. This was a single-center, open-label, cross-sectional study conducted at the Giresun University Faculty of Medicine, Physical Medicine and Rehabilitation Department, between November 2019 and August 2020. This study included 26 ankylosing spondylitis patients receiving adalimumab for at least 1 year and 21 healthy controls. All subjects underwent a full ophthalmological examination and optical coherence tomography examination with the following measurements: peripapillary retinal nerve fiber layer thickness, peripapillary retinal thickness, peripapillary choroidal thickness, ganglion cell complex thickness, and the optic head properties. Peripapillary retinal nerve fiber layer thickness and retinal thickness measurements were lower in the adalimumab group. In addition, ganglion cell complex thickness was significantly lower and the cup-to-disc ratio was significantly higher in the adalimumab group (p<0.05). However, the two groups did not differ in terms of peripapillary choroidal thickness and disc area (p>0.05). Although tumor necrosis factor-alpha inhibitors have some favorable effects on the ocular involvement of patients with ankylosing spondylitis, they may also have paradoxical detrimental effects as evidenced by structural changes observed by optical coherence tomography. Future studies with better design, probably including a large number of patients with a range of rheumatological diseases and tumor necrosis factor-alpha inhibitors, are warranted.

Deep Learning Estimation of 10-2 Visual Field Map Based on Circumpapillary Retinal Nerve Fiber Layer Thickness Measurements

To estimate central 10-degree visual field (VF) map from spectral-domain optical coherence tomography (SD-OCT) retinal nerve fiber layer thickness (RNFL) measurements in glaucoma with artificial intelligence. Artificial intelligence (convolutional neural networks) study. This study included 5352 SD-OCT scans and 10-2 VF pairs from 1365 eyes of 724 healthy patients, patients with suspected glaucoma, and patients with glaucoma. Convolutional neural networks (CNNs) were developed to estimate the 68 individual sensitivity thresholds of 10-2 VF map using all-sectors (CNNA) and temporal-sectors (CNNT) RNFL thickness information of the SD-OCT circle scan (768 thickness points). 10-2 indices including pointwise total deviation (TD) values, mean deviation (MD), and pattern standard deviation (PSD) were generated using the CNN-estimated sensitivity thresholds at individual test locations. Linear regression (LR) models with the same input were used for comparison. The CNNA model achieved an average pointwise mean absolute error of 4.04 dB (95% confidence interval [CI] 3.76-4.35) and correlation coefficient (r) of 0.59 (95% CI 0.52-0.64) over 10-2 map and the mean absolute error and r of 2.88 dB (95% CI 2.63-3.15) and 0.74 (95% CI 0.67-0.80) for MD, and 2.31 dB (95% CI 2.03-2.61) and 0.59 (95% CI 0.51-0.65) for PSD estimations, respectively, significantly outperforming the LRA model. The proposed CNNA model improved the estimation of 10-2 VF map based on circumpapillary SD-OCT RNFL thickness measurements. These artificial intelligence methods using SD-OCT structural data show promise to individualize the frequency of central VF assessment in patients with glaucoma and would enable the reallocation of resources from patients at lowest risk to those at highest risk of central VF damage.