Retinal Thickness Analyzer Research Articles

The use of optical coherence tomography in neuro-ophthalmology

In the last decade, with the advances of optical coherence tomography (OCT) technology, different imaging protocols and analysis algorithms have been introduced to maximize the potential of this diagnostic tool in the evaluation of different eye diseases. This review aims to provide an update on these additional features, with respect to the management of a diverse range of neuro-ophthalmologic conditions. Macular ganglion cell complex (mGCC) analysis has been shown to be superior to peripapillary retinal nerve fiber layer (pRNFL) analysis in certain settings, such as differentiating Leber's hereditary optic neuropathy from functional visual loss; monitoring neurodegenerative diseases or multiple sclerosis; and predicting visual loss in nonarteritic ischemic optic neuropathy. mGCC analysis also demonstrates high correlation with perimetry and might serve as an early structural indicator of irreversible neuronal loss. Compared to pRNFL, retinal thickness analysis of the optic nerve head demonstrates better correlation with the severity of papilledema, thus enabling its possible application in detecting raised intracranial pressure, especially in the pediatric group. Upcoming research on emerging OCT technologies including OCT-angiography, enhanced depth imaging, retinal single-layer analysis and portable systems will hopefully further enhance the utility of OCT in the field. It is crucial for neuro-ophthalmologists to be updated and familiar with these newer OCT imaging protocols and to make appropriate choices for different clinical scenarios, in order to optimize the diagnostic sensitivity and specificity.

Internal retinal layer thickness and macular migration after internal limiting membrane peeling in macular hole surgery.

To provide a spectral-domain optical coherence tomography (SD-OCT)-based analysis of retinal layers thickness and nasal displacement of closed macular hole after internal limiting membrane peeling in macular hole surgery. In this nonrandomized prospective interventional study, 36 eyes of 32 patients were subjected to pars plana vitrectomy and 3.5 mm diameter internal limiting membrane (ILM) peeling for idiopathic macular hole (IMH). Nasal and temporal internal retinal layer thickness were assessed with SD-OCT. Each scan included optic disc border so that distance between optic disc border and fovea were measured. Thirty-six eyes had a successful surgery with macular hole closure. Total nasal retinal thickening (p<0.001) and total temporal retinal thinning (p<0.0001) were observed. Outer retinal layers increased thickness after surgery (nasal p<0.05 and temporal p<0.01). Middle part of inner retinal layers (mIRL) had nasal thickening (p<0.001) and temporal thinning (p<0.05). The mIRL was obtained by deducting ganglion cell layer (GCL) and retinal nerve fiber layer (RNFL) thickness from overall thickness of the inner retinal layer. Papillofoveal distance was shorter after ILM peeling in macular hole surgery (3,651 ± 323 μm preoperatively and 3,361 ± 279 μm at 6 months; p<0.0001). Internal limiting membrane peel is associated with important alteration in inner retinal layer architecture, with thickening of mIRL and shortening of papillofoveal distance. These factors may contribute to recovery of disrupted foveal photoreceptor and vision improvement after IMH closure.

Comparative analysis of mean retinal thickness measured using SD-OCT in normal young or old age and glaucomatous eyes.

To evaluate changes in macular thickness, ganglion cell layer/inner plexiform layer (GCL/IPL) thickness, and retinal nerve fiber layer (RNFL) thickness in normal eyes and glaucomatous eyes using spectral domain optical coherence tomography (SD-OCT). We enrolled 89 eyes (all left eyes), including 45 (of 45 patients) eyes with glaucoma and 44 (of 44 patients) normal eyes. The data from macular measurements using spectral domain optical coherence tomography were analyzed according to groups divided by age and glaucoma status. The macular thickness analysis, GCL/IPL thickness, and RNFL thickness values determined by SD-OCT scans were compared among the groups. Mean macular thickness decreased significantly with age or glaucoma. Mean GCL/IPL thickness decreased significantly in glaucomatous eyes in all sectors but did not decrease with age. Mean RNFL thickness, which was divided into four quadrants (superior, nasal, inferior, and temporal), decreased significantly in glaucomatous eyes at all quadrants and decreased in the temporal quadrant with age in non-glaucomatous eyes. No significant differences were detected between eyes with normal tension glaucoma (NTG) and primary open angle glaucoma (POAG) in all sectors of mean GCL/IPL thickness, RNFL thickness, and macular thickness. No significant difference in mean thickness was detected between eyes with NTG and POAG. Some of the sectors of RNFL thickness decreased with age or glaucoma. GCL/IPL thickness, however, decreased in glaucomatous eyes but not with age. Therefore, GCL/IPL thickness is less influenced by age when monitoring patients with glaucoma or suspect glaucoma.

Arrested Foveal Development in Preterm Eyes: Thickening of the Outer Nuclear Layer and Structural Redistribution Within the Fovea

The aim of this study was to define landmarks to better characterize foveal microstructure in normal subjects and in preterms with or without signs of immaturity, and to report on thickness changes of outer foveal layers following analysis of optical coherence tomography (OCT) B-scan images. Selected eyes from eight young adults with a history of prematurity (24-33 weeks of gestation) and five controls were imaged using conventional and directional OCT. Retinal layer thickness analysis was performed at selected temporal eccentricities defined by the individual distance between two landmarks for each case, the foveal center and the foveal rim. The use of a foveal center and foveal rim landmark transformation enabled comparisons of interindividual B-scans at corresponding landmark positions in both controls and preterms. We found a 20% shorter foveal center to foveal rim distance in preterms with an immature fovea than in controls. Reflectometric and manual segmentation measurements showed increased thickness of inner retinal layers and photoreceptor cell body and outer plexiform layers centrally, but no observable change of photoreceptor inner and outer segment thickness. Our landmark-based analysis of OCT images using reflectometry and manual segmentation provides complementary findings in comparisons of normal and immature foveal structures. We show a central thickness increase in the outer nuclear layer, outer plexiform layer, and postreceptor layers in preterms with signs of arrested foveal development. We found no indication of abnormal photoreceptor inner or outer segment development in preterms.

Analysis of Macular and Retinal Nerve Fiber Layer Thickness in Children with Refractory Amblyopia after Femtosecond Laser-assisted Laser In situ Keratomileusis: A Retrospective Study.

Background:Localized macular edema and retinal nerve fiber layer (RNFL) thinning have been reported shortly after laser in situ keratomileusis (LASIK) in adults. However, it is still unclear how LASIK affects the retina of children. This study aimed to investigate the macular retina and RNFL thickness in children with refractive amblyopia who underwent femtosecond laser-assisted LASIK (FS-LASIK).Methods:In this study, we included 56 eyes of 32 patients with refractive amblyopia who underwent FS-LASIK in our hospital from January 2012 to December 2016. Foveal (foveal center retinal, parafoveal retinal, and perifoveal), macular inner retinal (superior and inferior), and peripapillary RNFL thicknesses (superior, inferior, temporal, and nasal) were measured using Fourier-domain optical coherence tomography before surgery and 1 day, 3 days, and 1 week after surgery. We divided these patients into three groups based on their refractive error: High myopic group with 22 eyes (equivalent sphere, >6.00 D), mild myopic group with 19 eyes (equivalent sphere, 0–6.00 D), and hyperopic group with 15 eyes (equivalent sphere, >+0.50 D). We compared the macular retina and RNFL thickness before and after LASIK. A paired simple t-test was used for data analysis.Results:One week after surgery, the visual acuity for all 56 eyes of the 32 patients reached their preoperative best-corrected vision. Visual acuity improved two lines or better for 31% of the patients. The residual refractive errors in 89% of the patients were within ±0.5 D. In the high myopic group, the foveal center retinal and parafoveal retinal thicknesses were thicker 1 day and 3 days after surgery than before surgery (t = 2.689, P = 0.012; t = 2.383, P = 0.018, respectively); no significant difference was found 1 week after surgery (P > 0.05). The foveal center retinal and parafoveal retinal thicknesses were greater 1 day after surgery than they were before surgery (P = 0.000 and P = 0.005, respectively) in the mild myopic and hyperopic groups. No significant difference was found 3 days or 1 week after surgery (P > 0.05). In all three groups, no significant difference was found in the macular inner retinal or peripapillary RNFL thickness 1 day, 3 days, or 1 week after surgery (P > 0.05).Conclusions:The foveal center retinal edema after FS-LASIK is mild and reversible in children, that mostly occurred in the high myopic group with no effect on the visual acuity, and is always relieved within 1 week.

Clinical analysis of retinal nerve fiber layer thickness and macular fovea in hyperopia children with anisometropia amblyopia

Clinical analysis of retinal nerve fiber layer thickness and macular fovea in hyperopia children with anisometropia amblyopia

Interest of analysis of circumpapillary retinal nerve fibers layer thickness at different measurement diameters

PurposeThe analysis of the circumpapillary retinal nerve fiber layer (RNFL) is a major data in structural analysis in glaucoma. Since OCT development, analysis is on a circle of 3.4 mm diameter. This study evaluates the diagnostic capability of an RNFL analysis with different diameter measurements.Methods60 glaucomatous and 58 control patients had a complete ophthalmological exam to exclude patients with papillary morphological abnormalities (coloboma, dysversion …). Others had an OCT Spectralis (Heidelberg Engineering, Germany) of RNFL on 4 circles of different diameters: 3.4, 3.5, 4.1 and 4.7 mm. Only one eye per patient was randomly included. The diagnostic capabability of each of these circles was analyzed for global mean thickness and for each sector (temporal, temporal‐superior, nasal‐superior, nasal, nasal‐inferior and temporal‐inferior) by calculating areas under ROC curve (AUROC).ResultsPatients were comparable for clinical characteristics. In glaucomatous patient group, 58.9% of the patients were early glaucoma (MD&gt; ‐6 dB) and 21.4% of the patients were severe (MD &lt;‐12 dB). For conventional RNFL measurement (3.4 mm), the temporal‐inferior sector had the highest diagnostic capability with an AUROC of 0.916. For the 3.5 mm measurement, the global mean thickness of the RNFL had the highest diagnostic capability (AUROC = 0.909). For the 4.1 mm measurement, the global mean thickness of the RNFL had the highest diagnostic capability (AUROC = 0.915). For the 4.7 mm measurement, the average thickness of the temporal‐inferior sector had the highest diagnostic capability (AUROC = 0.909). There was no statistically significant difference between these 4 AUROC.ConclusionsRegardless of the diameter of RNFL analysis, the diagnostic capability remains very good with no significant difference in patients with normal papillary morphology.

Redistribution within retinal layers of the central fovea in preterms with developmental arrest

PurposeThe aim of this study was to characterize thickness changes of foveal layers in preterms with or without signs of immaturity compared to control subjects through analysis of optical coherence tomography (OCT) B‐scan images.MethodsSelected eyes from 8 young adults with a history of prematurity (24‐33 weeks of gestation) and 5 controls were imaged using conventional and directional OCT. Retinal layer thickness analysis was performed at selected temporal eccentricities defined by the individual distance between two landmarks for each case, the foveal center (FC) and the foveal rim (R).ResultsThe use of an FC/R landmark transformation enabled comparisons of thickness profiles and area calculations from inter‐individual B‐scans at corresponding landmark positions in both controls and preterms. Reflectometric and manual segmentation measurements showed increased thickness of inner retinal layers (IRL) and photoreceptor cell body and axon/pedicle layers within the central fovea. Thickness and areal differences between controls and preterms with signs of developmental arrest showed a marked redistribution of IRL and the layers of photoreceptor cell bodies, axons and pedicles/synapses within the central fovea. This is in line with incomplete displacement of these layers from the foveal center. Since no changes of photoreceptor inner and outer segment thickness were observed the maturation of the photoreceptor segment layers seems to be within normal limits.ConclusionsOur landmark‐based analysis of OCT images using reflectometry and manual segmentation provides complementary findings in comparisons of normal and immature foveal structures. The thickness increase in the outer nuclear, Henle fiber, outer plexiform and post‐receptor layers in preterms with signs of arrested foveal development indicate a marked redistribution of cells.

Skuteczność ranibizumabu w idiopatycznej neowaskularyzacji naczyniówkowej – opis serii przypadków

Objective: To evaluate the efficacy of the ranibizumab intravitreal injection in idiopathic choroidal neovascularization. Material and methods: The study included 3 patients (4 eyes), aged 17, 37 and 46, with visual acuity deterioration, warping and distortion of the central image lasting for 2–5 weeks. Inflammatory background of the disease was excluded. The baseline examination and follow-up included the best corrected visual acuity (BCVA), fluorescein angiography and central retinal thickness (CRT) analysis using optical coherence tomography (OCT). When ICNV was diagnosed, intravitreal injections of ranibizumab were administered. Results: During the first follow-up test, 3 eyes showed improvement of BCVA, and in the fourth eye BCVA remained unchanged. In funduscopy, all patients showed reduced haemorrhage and oedema of the central retina. The OCT showed a reduction of the CRT and improvement in the morphology of the macula. The observation period ranged from 4 to 55 months, and the number of repeated injections during the observation ranged from 2 to 5. Conclusions: Injections of ranibizumab into the vitreous brought a significant improvement in the function of the treated eye, and in the morphology of the retina in OCT.

Quantitative characteristics of sickle cell retinopathy in optical coherence tomography angiography

Early detection is an essential step for effective intervention of sickle cell retinopathy (SCR). Emerging optical coherence tomography angiography (OCTA) provides excellent three-dimensional (3D) resolution to enable label-free, noninvasive visualization of retinal vascular structures, promising improved sensitivity in detecting SCR. However, quantitative analysis of SCR characteristics in OCTA images is yet to be established. In this study, we conducted comprehensive analysis of six OCTA parameters, including blood vessel tortuosity, vessel diameter, vessel perimeter index (VPI), area of foveal avascular zone (FAZ), contour irregularity of FAZ and parafoveal avascular density. Compared to traditional retinal thickness analysis, five of these six OCTA parameters show improved sensitivity for SCR detection than retinal thickness. It is observed that the most sensitive parameters were the contour irregularity of FAZ in the superficial layer and avascular density in temporal regions, while the area of FAZ, tortuosity and mean diameter of the vessel were moderately sensitive.

Analysis of normal retinal nerve fiber layer thickness by age and sex using spectral domain tomography

Background: To analyze the nerve fiber layer thickness in a heterogeneous Indian population according to age and sex and to compare this parameter to published normative data on the Caucasian population to better understand the racial differences. Materials and Methods: A total of 400 patients of both gender belonging to various age groups were evaluated using Cirrus HD optical coherence tomography (OCT), Carl Zeiss, Meditec, Dublin. The results were evaluated and compared to determine the normal retinal nerve fiber layer thickness (RNFLT) and its variations with age and sex. Results: Average nerve fiber thickness along the 3.4 mm diameter circle around the optic nerve head was approximately 90.57 ± 11.59 μm. There was no significant difference seen between males and females for mean, quadrant, and clockwise RNFLT. This was the same in all the subgroups of our study. Conclusions: Our results provide the variations of RNFL in Indian population. To the best of our knowledge, this is the first study in our country done with a high sample size in the Cirrus HD-OCT machine.

Analysis of Ganglion Cell Complex and Retinal Nerve Fiber Layer Thickness in Glaucoma Diagnosis.

The aim was to compare retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thicknesses in patients with primary open angle glaucoma (POAG), ocular hypertension (OH) and healthy subjects, and to investigate the role of GCC parameters in glaucoma diagnosis. Eighty-one patients were divided into four groups according to Hodapp-Parrish-Anderson classification: 26 OH, 22 early POAG, 10 moderate to advanced POAG, and 23 healthy subjects. All patients underwent RNFL and GCC thickness measurement using SOCT Copernicus HR. All RNFL and GCC parameters were significantly lower in POAG than in OH and healthy subjects, especially Average RNFL, RNFL Superior and Inferior, GCC Average, and GGC Inferior. Of all RNFL parameters, the highest area under the receiver operating characteristic curve (AUC) was recorded for Average RNFL, 0.906. GCC Average, and GCC Superior and Inferior had the overall highest AUCs (0.957, 0.955 and 0.946, respectively) with 100% specificity. The RNFL Average and Inferior and GCC Average, Superior and Inferior were identified as the main predictors for development of glaucoma (p=0.015 and p=0.014 vs. p=0.002, p=0.002 and p=0.003, respectively). In conclusion, GCC parameters showed a slightly better glaucoma discriminating ability and were found to be better predictors for development of glaucoma as compared with RNFL.

Optical Coherence Tomography in the UK Biobank Study - Rapid Automated Analysis of Retinal Thickness for Large Population-Based Studies.

PurposeTo describe an approach to the use of optical coherence tomography (OCT) imaging in large, population-based studies, including methods for OCT image acquisition, storage, and the remote, rapid, automated analysis of retinal thickness.MethodsIn UK Biobank, OCT images were acquired between 2009 and 2010 using a commercially available “spectral domain” OCT device (3D OCT-1000, Topcon). Images were obtained using a raster scan protocol, 6 mm x 6 mm in area, and consisting of 128 B-scans. OCT image sets were stored on UK Biobank servers in a central repository, adjacent to high performance computers. Rapid, automated analysis of retinal thickness was performed using custom image segmentation software developed by the Topcon Advanced Biomedical Imaging Laboratory (TABIL). This software employs dual-scale gradient information to allow for automated segmentation of nine intraretinal boundaries in a rapid fashion.Results67,321 participants (134,642 eyes) in UK Biobank underwent OCT imaging of both eyes as part of the ocular module. 134,611 images were successfully processed with 31 images failing segmentation analysis due to corrupted OCT files or withdrawal of subject consent for UKBB study participation. Average time taken to call up an image from the database and complete segmentation analysis was approximately 120 seconds per data set per login, and analysis of the entire dataset was completed in approximately 28 days.ConclusionsWe report an approach to the rapid, automated measurement of retinal thickness from nearly 140,000 OCT image sets from the UK Biobank. In the near future, these measurements will be publically available for utilization by researchers around the world, and thus for correlation with the wealth of other data collected in UK Biobank. The automated analysis approaches we describe may be of utility for future large population-based epidemiological studies, clinical trials, and screening programs that employ OCT imaging.

Clinical and Anatomical Features of the Central Part of the Retina in Diabetic Macular Edema

1.1.Purpose: To study diagnostic criterion of the pathological process in patients with diabetic macular edema (DME): morphological changes of the retinal layers, light sensitivity, macular pigment optical density. 1.2.Methods: In this study 58 patients were divided in two groups. The first group (A) include 32 patients with DME (36 eyes), the second group (B) -26 patients (38 eyes) were without retinal pathology. Parameter estimation was conducted with the use of following methods: by optical coherence tomography (OCT) of macular area of the retina; photo-registration fundus with the measurement of the optical density of macular pigment (MPOD); microperimetry. 1.3.Results: OCT analysis showed that the inner nuclear and plexiform layers of retina were the most involved in pathological process and revealed significant differences in increase of mean retinal thickness in comparison with the control group. Analysis of MPOD revealed a significant reduction of all parameters in group A compared with the control group. On the basis of microperimetry of the central area of retina in group a light sensitivity indicators were reduced by an average of 10 dB and equaled 8.94±0.09 dB. Correlation analysis of retinal thickness, functional light sensitivity and optical density of macular pigment traced a strong connection (r = -0.94; p <0.05) between the indices of retinal thickness and MPOD. 1.4.Conclusion:Showed a sharp decrease in optical density of macular pigment determined by deficiency of lutein and zeaxanthin in patients with DME. A correlation between quantitative indicator of MPOD and area of edema was established.

Analysis of retinal and choroidal thickness in the macular area in patients with Parkinson's disease using swept‐source optical coherence tomography

PurposeTo analyze the retinal and choroidal thickness in the macular area in patients with Parkinson's disease (PD) using swept‐source optical coherence tomography (SS‐OCT) as a marker for neurodegenerative injury.Methods108 eyes of patients with PD and 90 eyes of healthy controls were included. All subjects underwent ophthalmologic evaluation including retinal and choroidal assessment using SS‐OCT Triton (Topcon), 3DH Wide protocol. Macular ETDRS data were analyzed, including retinal and choroidal thickness evaluation.ResultsPatients with PD revealed significant thinning compared to healthy controls concerning the outer nasal region of macular thickness (276.70 ± 17.64 μm in patients vs. 282.44 ± 9.64 μm in controls; p = 0.043). Regarding choroidal thickness, patients with PD revealed significant thickening compared to healthy controls in the inner nasal region (250.78 ± 99.50 μm in patients vs. 205.28 ± 81.62 μm in controls; p = 0.014), outer nasal region (207.11 ± 97.78 μm vs. 163.39 ± 70.02 μm; p = 0.011), inner inferior region (252.25 ± 96.54 μm vs. 213.65 ± 80.31 μm; p = 0.032) and outer inferior region (233.00 ± 89.10 μm vs. 200.15 ± 75.19 μm; p = 0.049).ConclusionsPD patients present reduced retinal thickness and increased choroidal thickness in the macular area compared to healthy subjects detectable with new SS‐OCT technology.

Analysis of the peripapillary retinal nerve fiber layer and choroidal thickness in patients with Parkinson's disease using swept‐source optical coherence tomography

PurposeTo analyze the thickness of several retinal layers and the thickness of the choroid in the peripapillary area in patients with Parkinson's disease (PD) using swept‐source optical coherence tomography (SS‐OCT) as a marker for neurodegenerative injury.Methods108 eyes of patients with PD and 90 eyes of healthy controls were included. All subjects underwent ophthalmologic evaluation, including retinal and choroidal assessment using SS‐OCT Triton (Topcon), 3DH Wide protocol. RNFL‐TSNIT data were analyzed in the peripapillary area, including retinal nerve fiber layer (RNFL), GCL+ layer (from RNFL to inner nuclear layer), GCL++ layer (from inner limiting membrane to inner nuclear layer) and choroidal thickness.ResultsPatients with PD revealed significant thinning in every retinal layer compared to healthy controls: average retinal thickness (280.25 ± 20.18 μm in patients vs. 288.18 ± 13.09 μm in controls; p = 0.013); inferotemporal sector of the RNFL thickness (135.08 ± 25.28 μm vs. 144.23 ± 17.19 μm; p = 0.024); superotemporal sector of the GCL+ layer thickness (38.52 ± 7.02 μm vs. 41.78 ± 9.24 μm; p = 0.047); inferotemporal sector of the GCL++ layer thickness (176.00 ± 28.07 μm vs. 187.07 ± 16.93 μm; p = 0.010). Contrary, patients with PD revealed significant thickening in total choroidal thickness compared to healthy controls (153.56 ± 62.48 μm in patients vs. 125.64 ± 52.53 μm in controls; p = 0.012), choroidal nasal (152.73 ± 50.54 μm vs. 129.32 ± 54.86 μm; p = 0.024), choroidal temporal (165.82 ± 80.16 μm vs. 128.40 ± 50.81 μm; p = 0.003) and choroidal inferior thickness (129.90 ± 64.70 μm vs. 98.83 ± 51.67 μm; p = 0.006).ConclusionsPatients with PD present significant reduction of peripapillary retinal, RNFL and ganglion cell layer thickness and significant thickening of the choroid in the peripapillary area detectable with new SS‐OCT technology.

Optical coherence tomography to distinguish Parkinson disease versus supranuclear progressive palsy

PurposeThe aim of the study was to examine patterns of peripapillary andretinal layer damage as a potential marker of neurodegeneration in Parkinson'sdisease (PD) compared to progressive supranuclear palsy (PSP) with 2 SD‐ OCTdevices.MethodsPeripapillary retinal nerve fiber layer (pRNFL), macular thickness (MT)and ganglion cell layer inner plexiform analysis (GCA) by Cirrus and pRNFL analysis and automaticsingle retinal layers macular segmentation by Spectralis were used to evaluate38 patients with PD and 15 patients with PSP.ResultsMean average and superior RNFL by Cirrus were thicker in PD compared to PSP (p = 0.001). The mean central, superior, supero‐temporal and infero‐temporal RNFL thicknesses by Spectralis were also significantly higher in PD compared to PSP (p &lt; 0.05). Using Cirrus OCT, mean MT and all measurements by GCA were significantly higher in PD compared to PSP (p &lt; 0.002). The AUC was larger for minimum GCIPL (0.912) than for average GCIPL thickness (0.850). A minimum GCIPL thickness cut‐off value of 69 μm, was able to differentiate PSP from PD (Sensitivity: 91.7%; Specificity: 72.7%). Minimum and average GCIPL thicknesses significantly correlated with Hoehn and Yahr score (p &lt; 0.05), and with UPDRS (Unified Parkinson's Disease Rating Scale) (p &lt; 0.005).ConclusionsThedifferential diagnosis of Parkinsonian disorders is clinical one and not alwayseasy, especially at the onset of disease. In thecurrent study, the minimum GCIPL thickness was the most sensitiveparameter to differentiate PD from PSP and it was significantly correlated withneurological score. These findings may facilitate the differential diagnosisand give insight into the degenerative processes of atypical parkinsonian syndromes.

Evaluation of a Myopic Normative Database for Analysis of Retinal Nerve Fiber Layer Thickness.

Analysis of retinal nerve fiber layer (RNFL) abnormalities with optical coherence tomography in eyes with high myopia has been complicated by high rates of false-positive errors. An understanding of whether the application of a myopic normative database can improve the specificity for detection of RNFL abnormalities in eyes with high myopia is relevant. To evaluate the diagnostic performance of a myopic normative database for detection of RNFL abnormalities in eyes with high myopia (spherical equivalent, -6.0 diopters [D] or less). In this cross-sectional study, 180 eyes with high myopia (mean [SD] spherical equivalent, -8.0 [1.8] D) from 180 healthy individuals were included in the myopic normative database. Another 46 eyes with high myopia from healthy individuals (mean [SD] spherical equivalent, -8.1 [1.8] D) and 74 eyes from patients with high myopia and glaucoma (mean [SD] spherical equivalent, -8.3 [1.9] D) were included for evaluation of specificity and sensitivity. The 95th and 99th percentiles of the mean and clock-hour circumpapillary RNFL thicknesses and the individual superpixel thicknesses of the RNFL thickness map measured by spectral-domain optical coherence tomography were calculated from the 180 eyes with high myopia. Participants were recruited from January 2, 2013, to December 30, 2015. The following 6 criteria of RNFL abnormalities were examined: (1) mean circumpapillary RNFL thickness below the lower 95th or (2) the lower 99th percentile; (3) one clock-hour or more for RNFL thickness below the lower 95th or (4) the lower 99th percentile; and (5) twenty contiguous superpixels or more of RNFL thickness in the RNFL thickness map below the lower 95th or (6) the lower 99th percentile. Specificities and sensitivities for detection of RNFL abnormalities. Of the 46 healthy eyes and 74 eyes with glaucoma studied (from 39 men and 38 women), the myopic normative database showed a higher specificity (63.0%-100%) than did the built-in normative database of the optical coherence tomography instrument (8.7%-87.0%) for detection of RNFL abnormalities across all the criteria examined (differences in specificities between 13.0% [95% CI, 1.1%-24.9%; P = .01] and 54.3% [95% CI, 37.8%-70.9%; P < .001]) except for the criterion of mean RNFL thickness below the lower 99th percentile, in which both normative databases had the same specificities (100%) but the myopic normative database exhibited a higher sensitivity (71.6% vs 86.5%; difference in sensitivities, 14.9% [95% CI, 4.6%-25.1%; P = .002]). The application of a myopic normative database improved the specificity without compromising the sensitivity compared with the optical coherence tomography instrument's built-in normative database for detection of RNFL abnormalities in eyes with high myopia. Inclusion of myopic normative databases should be considered in optical coherence tomography instruments.

Comparison of optic nerve head topography in normal eyes using confocal laser scanning tomograph and retinal thickness analyzer

Background: To compare optic nerve head topography measurements by Heidelberg retina tomograph I (HRT) and retinal thickness analyser (RTA) and thereby to determine clinical agreement between the devices. To investigate reproducibility of measurements for HRT and RTA. To obtain our own HRT and RTA database for comparison of healthy and glaucomatous eyes. Methods: The study included 100 normal eyes of 50 white adults of both sexes (mean age of 55.5 [SD 9.5] years). Ophthalmologic examination, fundus photography, HRT and RTA examinations were performed. To determine reproducibility 10 volunteers repeated the examination after a week. For HRT and RTA measurements mean (SD), median, 5th and 95th percentile, range and coefficient of variation were calculated. Differences in topographic parameters between HRT and RTA were tested for significance. Clinical agreement was assessed with »limits of agreement« and reproducibility expressed by repeatability coefficient and intraclass correlation coefficient (ICC). Results: Significant differences (p 0.10 for RTA parameters cup area (0.15), rim area (0.19), maximum cup depth (0.13), height variation contour (0.11) and RNFL cross-sectional area (0.14). ICC was good (> 90%) for all parameters, except for mean RNFL thickness (89%) for HRT and height variation contour (84%) for RTA. Conclusions: The two devices cannot be used interchangeably. At present, clinical usefulness of HRT is superior to RTA due to better reproducibility of measurements, better software support, shorter duration of the examination and good comparability of our HRT database with the database included in the latest HRT software version. At the moment RTA is using the same database as HRT. Therefore, our RTA database provides a new basis for comparison of optic disc characteristics between healthy and glaucomatous eyes.

Glaucoma Diagnostic Ability of the New Circumpapillary Retinal Nerve Fiber Layer Thickness Analysis Based on Bruch's Membrane Opening.

To compare the diagnostic ability of the new spectral-domain optical coherence tomography (SD-OCT) algorithm for measuring circumpapillary retinal nerve fiber layer (RNFL) thickness centered on Bruch's membrane opening (BMO), with the conventional circumpapillary RNFL thickness measurement centered on the optic disc. In 75 eyes with primary open-angle glaucoma (POAG) and 71 healthy control eyes, circumpapillary RNFL thickness was measured with SD-OCT, first by centering the scan circle on the optic disc (RNFLDi), and then on the BMO (RNFLBMO). Difference between the topographic profiles of RNFLDi and RNFLBMO was compared and factors influencing any discrepancies between methods were investigated. Glaucoma diagnostic abilities of each method were assessed using the areas under receiver operating characteristic curve (AUCs). Axial length did not differ between POAG and healthy eyes. A longer axial length and larger width of externally oblique border tissue (BT) associated with tilted optic disc were the two major factors influencing discrepancies between RNFLBMO and RNFLDi (both P < 0.001). Compared with RNFLBMO, RNFLDi tended to result in a thinner nasal RNFL in eyes with externally oblique BT, while RNFLBMO and RNFLDi were comparable in eyes without externally oblique BT. The glaucoma diagnostic capabilities were generally comparable, but RNFLBMO was superior to RNFLDi in eyes having a larger width (>250 μm) of externally oblique BT (AUC = 0.933 vs. 0.843, respectively, P = 0.027). The new circumpapillary RNFL scanning algorithm centered on BMO may provide a more reliable RNFL profile in eyes with tilted optic discs, with a largely comparable glaucoma diagnostic ability to the conventional algorithm.