Henle fiber layer thickening and deficits in objective retinal function in participants with a history of multiple traumatic brain injuries.

Introduction: This study tested whether multiple traumatic brain injuries (TBIs) alter the structure of the Henle fiber layer (HFL) and degrade cell-specific function in the retinas of human participants. Methods: A cohort of case participants with multiple TBIs and a cohort of pair-matched control participants were prospectively recruited. Directional optical coherence tomography and scanning laser polarimetry measured HFL thickness and phase retardation, respectively. Full-field flash electroretinography (fERG) assessed retinal function under light-adapted (LA) 3.0, LA 30 Hz, dark-adapted (DA) 0.01, DA 3.0, and DA 10 conditions. Retinal imaging and fERG outcomes were averaged between both eyes, and paired t-tests or Wilcoxon signed-rank tests analyzed inter-cohort differences. Results: Global HFL thickness was significantly (p = 0.02) greater in cases (8.4 ± 0.9 pixels) than in controls (7.7 ± 1.1 pixels). There was no statistically significant difference (p = 0.91) between the cohorts for global HFL phase retardation. For fERG, LA 3.0 a-wave amplitude was significantly reduced (p = 0.02) in cases (23.5 ± 4.2 µV) compared to controls (29.0 ± 8.0 µV). There were no other statistically significant fERG outcomes between the cohorts. Discussion: In summary, the HFL thickens after multiple TBIs, but phase retardation remains unaltered in the macula. Multiple TBIs may also impair retinal function, indicated by a reduction in a-wave amplitude. These results support the potential of the retina as a site to detect TBI-associated pathology.

Association Between Retinal Nerve Fiber Layer Thickness and Incident Dementia in the European Prospective Investigation into Cancer in Norfolk Cohort.

BACKGROUND: Retinal nerve fiber layer (RNFL) thickness may reflect cerebral status. OBJECTIVE: This study assessed the relationship between RNFL thickness and incident all-cause dementia in the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) Eye Study. METHODS: Glaucoma detection with variable corneal compensation (GDx-VCC) and Heidelberg Retinal Tomograph II (HRT II) derived global mean RNFL thickness from dementia-free participants at baseline within the EPIC-Norfolk Eye Study were analyzed. Incident dementia was identified through linkage to electronic medical records. Cox proportional hazard mixed-effects regression models adjusted for key confounders were used to examine the associations between RNFL thickness and incident dementia in four separate models. RESULTS: 6,239 participants were included with 322 cases of incident dementia and mean age of 67.5-years old, with 49.7% women (median follow-up 13.2-years, interquartile range (11.7 to 14.6 years). Greater RNFL thickness (GDx-VCC) was not significantly associated with a lower risk of incident dementia in the full adjusted model [HR per quartile increase 0.95; 95% CI 0.82-1.10]. Similarly, RNFL thickness assessed with HRT II was also not associated with incident dementia in any model (full adjusted model; HR per quartile increase: 1.06; [95% CI 0.93-1.19]. Gender did not modify any associations under study. CONCLUSION: GDx-VCC and HRT II derived RNFL thickness are unlikely to be useful predictors of incident dementia. Higher resolution optical imaging technologies may clarify whether there are useful relationships between neuro-retinal morphology and brain measures.

Structure and function of retinal ganglion cells in subjects with a history of repeated traumatic brain injury.

This study tested whether repeated traumatic brain injuries (TBIs) alter the objective structure or the objective function of retinal ganglion cells (RGCs) in human subjects recruited from an optometry clinic. Case subjects (n = 25) with a history of repeated TBIs (4.12 ± 2.76 TBIs over 0-41 years) and healthy pair-matched control subjects (n = 30) were prospectively recruited. Retinal nerve fiber layer (RNFL) thickness was quantified with spectral-domain optical coherence tomography, and scanning laser polarimetry measured RNFL phase retardation. Measurements of the photopic negative response were made using full-field flash electroretinography. There was no statistically significant difference (p = 0.42) in global RNFL thickness between the case cohort (96.6 ± 9.4 microns) and the control cohort (94.9 ± 7.0 microns). There was no statistically significant difference (p = 0.80) in global RNFL phase retardation between the case cohort (57.9 ± 5.7 nm) and the control cohort (58.2 ± 4.6 nm). There were no statistically significant differences in the peak time (p = 0.95) of the PhNR or in the amplitude (p = 0.11) of the PhNR between the case cohort (69.9 ± 6.9 ms and 24.1 ± 5.1 µV, respectively) and the control cohort (70.1 ± 8.9 ms and 27.8 ± 9.1 µV, respectively). However, PhNR amplitude was more variable (p < 0.025) in the control cohort than in the case cohort. Within the case cohort, there was a strong positive (r = 0.53), but not statistically significant (p = 0.02), association between time since last TBI and PhNR amplitude. There was also a modest positive (r = 0.45), but not statistically significant (p = 0.04), association between time since first TBI and PhNR amplitude. Our results suggest that there were no statistically significant differences in the objective structure or in the objective function of RGCs between the case cohort and the control cohort. Future large, longitudinal studies will be necessary to confirm our negative results and to more fully investigate the potential interaction between PhNR amplitude and time since first or last TBI.

Arterial Hypertension and the Hidden Disease of the Eye: Diagnostic Tools and Therapeutic Strategies.

Hypertension is a major cardiovascular risk factor that is responsible for a heavy burden of morbidity and mortality worldwide. A critical aspect of cardiovascular risk estimation in hypertensive patients depends on the assessment of hypertension-mediated organ damage (HMOD), namely the generalized structural and functional changes in major organs induced by persistently elevated blood pressure values. The vasculature of the eye shares several common structural, functional, and embryological features with that of the heart, brain, and kidney. Since retinal microcirculation offers the unique advantage of being directly accessible to non-invasive and relatively simple investigation tools, there has been considerable interest in the development and modernization of techniques that allow the assessment of the retinal vessels' structural and functional features in health and disease. With the advent of artificial intelligence and the application of sophisticated physics technologies to human sciences, consistent steps forward have been made in the study of the ocular fundus as a privileged site for diagnostic and prognostic assessment of diverse disease conditions. In this narrative review, we will recapitulate the main ocular imaging techniques that are currently relevant from a clinical and/or research standpoint, with reference to their pathophysiological basis and their possible diagnostic and prognostic relevance. A possible non pharmacological approach to prevent the onset and progression of retinopathy in the presence of hypertension and related cardiovascular risk factors and diseases will also be discussed.

Foveal Phase Retardation Correlates With Optically Measured Henle Fiber Layer Thickness.

This study quantified and compared phase retardation distribution in the central macula with the thickness of the Henle fiber layer (HFL). A scanning laser polarimeter (SLP) was used to acquire 20° × 40° macular-centered images, either with fixed corneal compensation or with variable corneal compensation, in two cohorts of clinically normal subjects (N = 36). Phase retardation maps from SLP imaging were used to generate a macular cross pattern (fixed compensation) or an annulus pattern (variable compensation) centered on the macula. Intensity profiles in the phase retardation maps were produced using annular regions of interest at eccentricities from 0.25° to 3°. Pixel intensity was averaged at each eccentricity, acting as a surrogate for macular phase retardation. Directional OCT images were acquired in the horizontal and vertical meridians in all subjects, allowing visualization of the HFL thickness. HFL thickness was manually segmented in each meridian and averaged. In both cohorts, phase retardation and HFL thickness were highly correlated in the central 3° assessed, providing further evidence that the source of the phase retardation signal in the central macula is dominated by the HFL and that the center of the macula on cross sectional imaging corresponds closely with the center of the macular cross on SLP imaging.

Retinal nerve fibre layer thickness measurements in childhood glaucoma: the role of scanning laser polarimetry and optical coherence tomography.

PURPOSE: A central diagnostic tool in adult glaucoma is the peripapillary retinal nerve fibre layer (pRNFL) thickness. It can be assessed by scanning laser polarimetry (SLP) or optical coherence tomography (OCT). However, studies investigating the relevance of pRNFL measurements in children are rare. This study aims to compare the glaucoma diagnosing ability of SLP and OCT pRNFL thickness measurements in a paediatric population. METHODS: This retrospective study included 105 children (glaucoma: 22 (21.0%); healthy glaucoma suspects: 83 (79.0%)) aged 4-18 years, examined with SLP (GDxPro/ECC, Carl Zeiss Meditec) and spectral-domain OCT (SPECTRALIS®, Heidelberg Engineering). The thickness of pRNFL sectors was compared between diseased and healthy participants. Areas under the receiver-operating characteristic curves (AUC) and logistic regression results were used to compare the glaucoma discriminative capacity between SLP and OCT measurements. RESULTS: Using OCT, pRNFL thickness was decreased in the superior, nasal, and inferior quadrants of glaucoma patients compared to healthy controls (P < 0.001, each). With SLP, such a difference was only observed in the inferior quadrant (P = 0.011). A correlation between glaucoma diagnosis and OCT-measured pRNFL thickness was found in all quadrants (P < 0.001) other than the temporal. With SLP, a correlation was found for the total average thickness (P = 0.037) and inferior quadrant (P = 0.0019). Finally, the AUCs of OCT measurements were markedly higher than those of SLP (e.g., inferior quadrant: OCT 0.83, SLP 0.68). CONCLUSION: pRNFL thickness measurements using both OCT and SLP, correlate notably with the presence of glaucoma. In general, the diagnostic performance of pRNFL thickness measurements seems higher for OCT than for SLP. Thus, pRNFL thickness measurements could provide important information, complementing conventional clinical and functional parameters in the diagnostic process of paediatric glaucoma.

Diagnostic performance of modern imaging instruments in glaucoma screening.

AIM: To evaluate the applicability of imaging devices (spectral-domain optical coherence tomography (Cirrus SD-OCT), scanning laser polarimetry (GDx) and scanning laser ophthalmoscopy (Heidelberg Retinal Tomograph, HRT3)) for glaucoma screening in a middle-aged unselected population. METHODS: Participants of the population-based Northern Finland Birth Cohort Eye Study, aged 45 to 49 years, underwent a comprehensive eye examination including modern imaging with five methods (retinal nerve fibre layer (RNFL) and macular ganglion cell layer +inner plexiform layer (GCIPL) analysis and their combination with SD-OCT, GDx and HRT). The performance of the automated classification of the imaging devices was assessed using a clinical glaucoma diagnosis as reference, that is, the '2 out of 3' rule based on the evaluation of optic nerve head and RNFL photographs and visual fields. RESULTS: We examined 6060 eyes of 3039 subjects; in the clinical evaluation, glaucomatous damage was found in 33 subjects (1.1%) in 43 eyes. The following sensitivities were obtained; RNFL analysis (53%), GCIPL analysis (50%), OCT combination analysis (61%), GDx (56%) and HRT (31%) with corresponding specificities of 95%, 92%, 90%, 88% and 96%. The area under the curve values were 0.76, 0.73, 0.75, 0.75 and 0.73, respectively. Post-test probabilities of glaucoma after positive imaging finding with each of these methods in this unselected population were 11%, 7%, 6%, 5% and 7%, respectively. CONCLUSION: Screening capabilities of the OCT, GDx and HRT were rather similar. The accuracy of all evaluated parameters was only moderate and thus screening with these parameters alone is not reliable.

The effect of panretinal photocoagulation on confocal laser scanning ophthalmoscopy and stereo photographic parameters of optic disk topography in patients with diabetic retinopathy / Efeito da panfotocoagulação retiniana na oftalmoscopia confocal de varredura a laser e parâmetros da estereofotografia do disco óptico em pacientes com retinopatia diabética

ABSTRACT Purpose: To determine the effect of panretinal photocoagulation on optic disk topographic parameters in non-glaucomatous patients with proliferative diabetic retinopathy. Methods: This was a prospective, single-center, observational study. Thirty-eight eyes of 26 patients with diabetes underwent panretinal photocoagulation for proliferative diabetic retinopathy. Stereoscopic disk photographs and optic nerve head parameters were evaluated using the Zeiss fundus camera and the confocal scanning laser ophthalmoscope (Heidelberg Retinal Tomograph), respectively, at baseline and 12 months after the completion of panretinal photocoagulation. Results: Thirty-eight eyes of 26 patients (15 female) with a mean age of 53.7 (range 26-74) years were recruited. No significant difference was found between the stereo photography determined mean horizontal and vertical cup-to-disk ratio before and after panretinal photocoagulation treatment (p=0.461 and 0.839, respectively). The global values of the optic nerve head parameters analyzed with the HRT3 showed no significant change from baseline to 12 months, including the disk area, cup area, rim area, cup volume, rim volume, cup-to-disk area ratio, linear cup-to-disk ratio, mean cup depth, maximum cup depth, cup shape measure, height variation contour, mean retinal nerve fiber layer thickness, and cross-sectional area. Conclusion: Our results suggest that panretinal photocoagulation does not cause morphological optic disk changes in patients with diabetic proliferative retinopathy after 1 year of follow-up.

RESUMO Objetivo: Determinar o efeito da panfotocoagulação retiniana nos parâmetros topográficos do disco óptico em pacientes não glaucomatosos com retinopatia diabética proliferativa. Métodos: Este é um estudo observacional pros­pectivo e unicêntrico. Trinta e oito olhos de 26 pacientes dia­béticos foram submetidos à panfotocoagulação retiniana para retinopatia diabética proliferativa. As estereofotografias e os parâmetros do disco óptico foram avaliados usando o retinógrafo Visucam da Zeiss e o oftalmoscópio confocal de varredura a laser (Heidelberg Retinal Tomograph), respectivamente, no início e 12 meses após a conclusão da panfotocoagulação. Resultados: Trinta e oito olhos de 26 pacientes (15 mulheres) com média de idade de 53,7 anos (intervalo de 26-74) foram recrutados. Nenhuma diferença significativa foi encontrada entre a média horizontal e vertical para relação escavação/disco óptico determinadas pelas estereo­fotografias antes e após o tratamento com panfotocoagulação retiniana (p=0,461 e 0,839, respectivamente). Os valores globais dos parâmetros do disco óptico analisados com a tomografia de varredura a laser não mostraram nenhuma mudança significativa entre o início até os 12 meses, incluindo disk area, cup area, rim area, cup volume, rim volume, C/D area ratio, linear C/D ratio, mean cup depth, maximum cup depth, cup shape measure, height variation contour, mean retinal nerve fiber layer thickness e cross-sectional area. Conclusão: Nossos resultados sugerem que a panfotocoagulação retiniana não causa alterações morfológicas no disco óptico em pacientes com retinopatia diabética proliferativa após um ano de seguimento.

Assessment of the retinal nerve fiber layer in individuals with obstructive sleep apnea.

BACKGROUND: The effect of obstructive sleep apnea (OSA) syndrome in the peripapillary retinal nerve fiber layer (RNFL) thicknesses remains unclear. The purpose of this study was to assess RNFL measurements acquired using scanning laser polarimetry (SLP) and optical coherence tomography (OCT) in patients with OSA. METHODS: The sample of this cross-sectional study included 40 OSA patients and 45 age-matched controls, consecutively and prospectively selected. All participants underwent at least one reliable standard automated perimetry (SAP) test, while RNFL measurements were obtained using the SLP and OCT. The OSA group was divided into 3 sub-groups based on the apnea/hypopnea index (AHI): mild, moderate, or severe OSA. SAP, SLP, and OCT outcomes were compared between the control and OSA groups. The relationship between AHI and RNFL parameters was also evaluated. RESULTS: Age was not different between both groups. Mean deviation of SAP was -0.47 ± 0.9 dB and -1.43 ± 2.3 dB in the control and OSA groups, respectively (p = 0.01). RNFL thickness measured with OCT was similar between groups. OSA patients showed increased nerve fiber indicator (NFI; 20.9 ± 7.9 versus 16.42 ± 7.82; p = 0.01) and decreased superior average (59.74 ± 10.35 versus 63.73 ± 6.58; p = 0.03) obtained with SLP compared with healthy individuals. In the total sample, NFI and AHI were moderately correlated (r = 0.358; p = 0.001). In severe OSA subjects (n = 22), NFI and AHI had a Spearman correlation coefficient of 0.44 (p = 0.04). CONCLUSION: RNFL thickness measured with OCT did not differ significantly between groups. Severe OSA was related to a reduction of the RNFL thickness assessed by SLP.

Photopic negative response of full-field electroretinography in patients with different stages of glaucomatous optic neuropathy.

PURPOSE: To evaluate photopic negative response (PhNR) discrimination ability between healthy and glaucomatous patients. METHODS: Ninety eyes of 50 patients with primary open angle glaucoma (POAG) and 45 eyes of 23 healthy age- and sex-matched controls were investigated. Based on European Glaucoma Society criteria, POAG patients were divided into three groups: early, moderate and advanced glaucoma. Following measurements were analysed: mean defect (MD) from Humphrey Visual Field Analyzer, SITA standard 24-2 white on white perimetry; nerve fibre index (NFI) obtained from scanning laser polarimetry; and GDx and PhNR amplitude and PhNR/b-wave ratio. PhNR was elicited by red stimuli with flash strength of 1.6 cd s/m(2) on blue background of 25 cd/m(2). Correlations between retinal ganglion cells function (PhNR), retinal sensitivity (MD) and structure (NFI) were calculated. Sensitivity and specificity of PhNR parameters were calculated with standard formulas. Receiver operating characteristic (ROC) curves were used to determine optimal cut-off values. The area under the curve (AUC) was used to compare the ROC curves results between PhNR amplitude and ratio. RESULTS: PhNR amplitude and ratio were significantly reduced in early, moderate and advanced glaucoma groups compared to controls. The sensitivity and specificity to detect glaucoma in early POAG were equal to 53.3 and 90.0% for PhNR amplitude and 60.0 and 70.0% for PhNR ratio; in moderate POAG 63.3 and 80.0% for PhNR amplitude and 60.0 and 86.7% for PhNR ratio; and in advanced POAG 76.6 and 80.0% for PhNR amplitude, 90.0 and 73.3% for PhNR ratio. There were no significant differences between AUC for PhNR amplitude (0.76-0.86) and PhNR ratio (0.78-0.86), p > 0.05. PhNR amplitudes and ratios correlated significantly with MD measured by SAP and NFI obtained from GDx (p < 0.05). PhNR amplitude significantly decreases with advancement of visual field defects in glaucoma patients. CONCLUSIONS: PhNR reveals dysfunction of RGCs in early, moderate and advanced stage of POAG. PhNR has good discrimination ability in detecting glaucomatous patients. PhNR might be a useful test in glaucoma diagnosis.

Scanning laser polarimetry and spectral domain optical coherence tomography for the detection of retinal changes in Parkinson's disease.

PURPOSE: Whether retinal degeneration is part of the degenerative processes in patients with Parkinson's disease (PD) is still unclear. This cross-sectional study was undertaken to compare the retinal morphology of patients with PD and healthy controls using spectral domain optical coherence tomography (SD-OCT) and scanning laser polarimetry (SLP). METHODS: Both eyes of patients with PD (n = 108) and healthy controls (n = 165) were examined using SD-OCT and SLP on the same day. Data on the thickness of the retinal nerve fibre layer (RNFL) of all quadrants and the macular area were acquired by OCT (Cirrus, Zeiss). The SLP device (Glaucoma diagnostics (GDx), Zeiss) measured the RNFL and calculated the nerve fibre index (NFI). All patients and probands were checked for concomitant ocular disorders by an ophthalmologist. Visual acuity, intraocular pressure (IOP), objective refraction and the anterior and posterior segment were assessed. RESULTS: Patients with PD showed a reduced macular volume and a reduced central subfield thickness in OCT examinations. The RNFL in the different quadrants did not differ significantly from that of controls. SLP data showed a reduced average RNFL thickness, a decreased thickness of the inferior quadrant and an increase of the NFI in patients with PD. CONCLUSION: PD may be associated with reduced thickness and volume of the macula and a reduced thickness of the RNFL in the inferior quadrant of the retina. Investigations using SD-OCT and SLP revealed distinct but significant differences between patients with PD and healthy controls.

In vivo imaging methods to assess glaucomatous optic neuropathy.

The goal of this review is to summarize the most common imaging methods currently applied for in vivo assessment of ocular structure in animal models of experimental glaucoma with an emphasis on translational relevance to clinical studies of the human disease. The most common techniques in current use include optical coherence tomography and scanning laser ophthalmoscopy. In reviewing the application of these and other imaging modalities to study glaucomatous optic neuropathy, this article is organized into three major sections: 1) imaging the optic nerve head, 2) imaging the retinal nerve fiber layer and 3) imaging retinal ganglion cell soma and dendrites. The article concludes with a brief section on possible future directions.

Optical coherence tomography, scanning laser polarimetry and confocal scanning laser ophthalmoscopy in retinal nerve fiber layer measurements of glaucoma patients.

PURPOSE: To determine the correlations and strength of association between different imaging systems in analyzing the retinal nerve fiber layer (RNFL) of glaucoma patients: optical coherence tomography (OCT), scanning laser polarimetry (SLP) and confocal scanning laser ophthalmoscopy (CSLO). MATERIALS AND METHODOLOGY: 114 eyes of patients with moderate open angle glaucoma underwent spectral domain OCT (Topcon SD-OCT 2000 and Zeiss Cirrus HD-OCT), SLP (GDx VCC and GDx Pro) and CSLO (Heidelberg Retina Tomograph, HRT 3). Correlation coefficients were calculated between the structural parameters yielded by these examinations. The quantitative relationship between the measured RNFL thickness globally and for the four regions (superior, inferior, nasal, temporal) were evaluated with different regression models for all used imaging systems. RESULTS: The strongest correlation of RNFL measurements was found between devices using the same technology like GDx VCC and GDx Pro as well as Topcon OCT and Cirrus OCT. In glaucoma patients, the strongest associations (R²) were found between RNFL measurements of the two optical coherence tomography devices Topcon OCT and Cirrus OCT (R² = 0.513) and between GDx VCC and GDx Pro (R² = 0.451). The results of the OCTs and GDX Pro also had a strong quantitative relationship (Topcon OCT R² = 0.339 and Cirrus OCT R² = 0.347). GDx VCC and the OCTs showed a mild to moderate association (Topcon OCT R² = 0.207 and Cirrus OCT R² = 0.258). The confocal scanning laser ophthalmoscopy (HRT 3) had the lowest association to all other devices (Topcon OCT R² = 0.254, Cirrus OCT R² = 0.158, GDx Pro R² = 0.086 and GDx VCC R² = 0.1). CONCLUSION: The measurements of the RNFL in glaucoma patients reveal a high correlation of OCT and GDx devices because OCTs can measure all major retinal layers and SLP can detect nerve fibers allowing a comparison between the results of this devices. However, CSLO by means of HRT topography can only measure height values of the retinal surface but it cannot distinguish between different retinal layers. This may explain the rather poor correlations and associations between CSLO measurements and those of all other imaging devices which makes it difficult to compare HRT 3 nerve fiber data. These correlations are important in clinical routine especially when different techniques are used in the follow-up of glaucoma patients.

Morphological characteristics of the optic nerve evaluated by confocal laser tomography (HRT3) and laser polarimetry (GDx-VCC) in a normal population from the city of Barcelona.

OBJECTIVE: To evaluate morphological parameters of optic disc and retinal nerve fiber layer (RNFL) examined with confocal laser tomography (HRT3) and laser polarimetry (GDx-VCC) in a normal population, and analyze correlations of these parameters with demographic variables. PATIENTS AND METHODS: Cross-sectional study in the context of a glaucoma screening campaign in the primary care center of Barcelona. The individuals selected were non-hypertensive Mediterranean Caucasians with risk for glaucoma development (individuals≥60 years old or≥40 years old with family history of glaucoma or intraocular pressure or myopia>3diopter). All subjects underwent a complete ophthalmic examination, confocal laser tomography (HRT3) and scanning laser polarimetry (GDX-VCC), subjects with results within normal limits only being included. Structural parameters were analyzed along with age, refraction, and pachymetry based on the Spearman rank correlation test. RESULTS: A total of 224 subjects included, with a mean age of 63.4±11.1 years. Disc areas, excavation and ring area were 2.14±0.52mm(2), 0.44±0.34mm (2) and 1.69±0.38mm(2), respectively. The mean RNFL (GDX) was 55.9±6.9µm. Age was correlated with lower ring volume, highest rate of cup shape measure, largest mean and maximum cup depth, lower nerve fiber index (NFI) and RNFL (all p-values below .05). CONCLUSION: The mean values and distribution of several parameters of the papilla and the RNFL in normal Mediterranean Caucasians population are presented. A loss of thickness of the RNFL, ring thinning, and enlarged cup was observed with increased age.

Atypical birefringence pattern and the diagnostic ability of scanning laser polarimetry with enhanced corneal compensation in glaucoma.

PURPOSE: To evaluate the effect of typical scan score (TSS), when within the acceptable limits, on the diagnostic performance of retinal nerve fibre layer (RNFL) parameters with the enhanced corneal compensation (ECC) protocol of scanning laser polarimetry (SLP) in glaucoma. METHODS: In a cross-sectional study, 203 eyes of 160 glaucoma patients and 140 eyes of 104 control subjects underwent RNFL imaging with the ECC protocol of SLP. TSS was used to quantify atypical birefringence pattern (ABP) images. Influence of TSS on the diagnostic ability of SLP parameters was evaluated by receiver operating characteristic (ROC) regression models after adjusting for the effect of disease severity [based on mean deviation (MD)] on standard automated perimetry). RESULTS: Diagnostic abilities of all RNFL parameters of SLP increased when the TSS values were higher. This effect was statistically significant for TSNIT (coefficient: 0.08, p<0.001) and inferior average parameters (coefficient: 0.06, p=0.002) but not for nerve fibre indicator (NFI, coefficient: 0.03, p=0.21). In early glaucoma (MD of -5 dB), predicted area under ROC curve (AUC) for TSNIT average parameter improved from 0.642 at a TSS of 90 to 0.845 at a TSS of 100. In advanced glaucoma (MD of -15 dB), AUC for TSNIT average improved from 0.832 at a TSS of 90 to 0.947 at 100. CONCLUSION: Diagnostic performances of TSNIT and inferior average RNFL parameters with ECC protocol of SLP were significantly influenced by TSS even when the TSS values were within the acceptable limits. Diagnostic ability of NFI was unaffected by TSS values.

Henle fiber layer phase retardation changes associated with age-related macular degeneration.

PURPOSE: To quantify and compare phase retardation amplitude and regularity associated with the Henle fiber layer (HFL) between nonexudative AMD patients and age-matched controls using scanning laser polarimetry (SLP) imaging. METHODS: A scanning laser polarimeter was used to collect 15 × 15° macular-centered images in 25 patients with nonexudative AMD and 25 age-matched controls. Raw image data were used to compute macular phase retardation maps associated with the HFL. Consecutive, annular regions of interest from 0.5 to 3.0° eccentricity, centered on the fovea, were used to generate intensity profiles from phase retardation data and analyzed with two complementary techniques: a normalized second harmonic frequency (2f) of the fast Fourier Transform (FFT) analysis and a curve fitting analysis using a 2f sine function. Paired t-tests were used to compare the normalized 2f FFT magnitude at each eccentricity between the two groups, the eccentricity that yielded the maximum normalized 2f FFT between paired individuals across the two groups, and curve fitting RMS error at each eccentricity between the two groups. RESULTS: Normalized 2f FFT components were lower in the AMD group at each eccentricity, with no difference between the two groups in the maximum normalized 2f FFT component eccentricity. The root-mean-square (RMS) error from curve fitting was significantly higher in the AMD group. CONCLUSIONS: Phase retardation changes in the central macula indicate loss and/or structural alterations to central cone photoreceptors in nonexudative AMD patients. Scanning laser polarimetry imaging is a noninvasive method for quantifying cone photoreceptor changes associated with central macular disease.

Measurement of retinal nerve fiber layer thickness in eyes with optic disc swelling by using scanning laser polarimetry and optical coherence tomography.

BACKGROUND: The retinal nerve fiber layer thickness (RNFLT) in patients with optic disc swelling of different etiologies was compared using scanning laser polarimetry (SLP) and spectral-domain optical coherence tomography (OCT). METHODS: Forty-seven patients with optic disc swelling participated in the cross-sectional study. Both GDx SLP (enhanced corneal compensation) and Spectralis spectral-domain OCT measurements of RNFLT were made in 19 eyes with papilledema (PE), ten eyes with optic neuritis (ON), and 18 eyes with nonarteritic anterior ischemic optic neuropathy (NAION) at the neuro-ophthalmology clinic at Kyoto University Hospital. Differences in SLP (SLP-RNFLT) and OCT (OCT-RNFLT) measurements among different etiologies were investigated. RESULTS: No statistical differences in average OCT-RNFLT among PE, ON, and NAION patients were noted. Average SLP-RNFLT in NAION patients was smaller than in PE (P<0.01) or ON (P=0.02) patients. When RNFLT in each retinal quadrant was compared, no difference among etiologies was noted on OCT, but on SLP, the superior quadrant was thinner in NAION than in PE (P<0.001) or ON (P=0.001) patients. Compared with age-adjusted normative data of SLP-RNFLT, average SLP-RNFLT in PE (P<0.01) and ON (P<0.01) patients was greater. Superior SLP-RNFLT in NAION patients was smaller (P=0.026). The ratio of average SLP-RNFLT to average OCT-RNFLT was smaller in NAION than in PE (P=0.001) patients. CONCLUSION: In the setting of RNFL thickening, despite increased light retardance in PE and ON eyes, SLP revealed that NAION eyes have less retardance, possibly associated with ischemic axonal loss.

Corneal biomechanical properties and glaucoma-related quantitative traits in the EPIC-Norfolk Eye Study.

PURPOSE: We examined the association of corneal hysteresis (CH) with Heidelberg retina tomograph (HRT)- and Glaucoma Detection with Variable Corneal Compensation scanning laser polarimeter (GDxVCC)-derived measures in a British population. METHODS: The EPIC-Norfolk Eye Study is nested within a multicenter cohort study--the European Prospective Investigation of Cancer. Ocular response analyzer (ORA), HRT3, and GDxVCC measurements were taken at the research clinic. Three ORA measurements were taken per eye, and the single best value used. Participants meeting predefined criteria were referred for a second examination, including Goldmann applanation tonometry (GAT) and central corneal thickness (CCT) measurement. Generalized estimating equation models were used to examine the associations of CH with HRT and GDxVCC parameters, adjusted for disc area. The GDxVCC analyses were adjusted further for typical scan score to handle atypical retardation. RESULTS: There were complete research clinic data from 5134 participants. Corneal hysteresis was associated positively with HRT rim area (P < 0.001), and GDxVCC retinal nerve fiber layer (RNFL) average thickness (P = 0.006) and modulation (P = 0.003), and associated negatively with HRT linear cup-to-disc ratio (LCDR, P < 0.001), after adjustment for Goldmann-correlated IOP and other possible confounders. In the 602 participants undergoing the second examination, CH was associated negatively with LCDR (P = 0.008) after adjustment for GAT, CCT, and other possible confounders. CONCLUSIONS: Lower CH was associated with HRT and GDxVCC parameters in a direction that is seen in glaucoma and with ageing. Further research is required to establish if this is a causal relationship, or due to residual confounding by age, IOP, or CCT.

Análise de regressão logística na combinação de métodos propedêuticos no diagnóstico do glaucoma / Logistic regression analysis in the combination of diagnostic methods in glaucoma

OBJETIVOS: Estudar a habilidade diagnóstica do tomógrafo retiniano de Heidelberg (HRT II), GDx analisador de fibras nervosas (GDx), perimetria azul-amarelo (SWAP), tecnologia de frequência duplicada (FDT) isoladamente e em conjunto no diagnóstico do glaucoma. MÉTODOS: Sessenta glaucomatosos e 60 pacientes normais foram submetidos a exames de HRT II, GDx, SWAP e FDT. HRT foi considerado alterado quando pelo menos uma região do anel neurorretiniano esteve fora dos limites da normalidade, conforme a análise de regressão de Moorfields. GDx alterado foi definido quando pelo menos um índice foi considerado pelo programa do equipamento como fora dos limites normais, excluindo-se o índice simetria, ou ainda quando no gráfico "the deviation from normal graph" apareceu um quadrante com significância abaixo de 5%. O FDT foi considerado anormal quando pelo menos uma região testada apresentou-se com defeito severo ou com a presença de dois defeitos moderados contíguos. Para o SWAP foram adotados os critérios de anormalidade propostos por Anderson. Análise de regressão logística foi realizada. RESULTADOS: Quando foram estudadas as tecnologias isoladamente, a análise de regressão logística apresentou melhores índices de razão das chances para glaucoma com exames positivos para o HRT (22,49), seguido pelo SWAP (21,71). FDT (3,97) e GDx (2,73). Quando se associaram exames positivos de diferentes tecnologias, as razões das chances aumentaram. Nos casos com exames de HRT, FDT e SWAP fora dos limites normais, a razão das chances foi de 252,6 e com HRT, SWAP e GDx alterados, 173,1. Quando associamos exames positivos de diferentes tecnologias, a razão das chances dos pacientes serem glaucomatosos aumentou consideravelmente, chegando a 689,7 com todos os exames fora dos limites normais, o que ocorreu em 26 pacientes deste estudo. CONCLUSÕES: A análise de regressão logística confirmou que a presença de exames alterados de HRT ou SWAP apresentam as maiores razões das chances de glaucoma. A associação de exames alterados aumentou a razão das chances, principalmente, quando o HRT e o SWAP estavam fora dos limites normais.

PURPOSES: In this research was studied the diagnostic ability of the Heidelberg Retinal Tomograph (HRT II), GDx nerve fiber analyzer (GDx), Short-wavelenght Automated Perimetry (SWAP) and Frequency-doubling technology (FDT), all of them together and also separately in the diagnosis of glaucoma. METHODS: Sixty glaucomatous patients and 60 normal ones were submitted to examination with the technology of HRT II, GDx, FDT and SWAP. In the interpretation of HRT, based on the Moorfields regression analysis, were considered abnormal when at least one area of the neuroretinal ring was outside the bounds of normality. GDx was defined as altered, when it was observed that at least one index was considered by equipment program as outside of normal limits, excluding the index symmetry, or when "the deviation from normal graph" appeared a quadrant with significance below 5%. The FDT was considered abnormal when at least one region tested presented with severe defects, or two contiguous moderate defects in at least two reliable tests. For SWAP was adopted the abnormality criteria proposed by Anderson. Logistic regression analysis was performed. RESULTS: When the technologies were studied separately, the Logistic regression analysis showed better odds ratio rates to test positive for glaucoma with HRT (22.49), followed by EAP (21.71), FDT (3.97) and GDx (2.73). When positive tests were associated with different technologies, the odds ratios increased. In cases with HRT, FDT and PAA tests, outside normal bounds, the odds ratio was 252.6. Concerning the HRT, GDx and PAA the result have changed to 173.1. When we associate positive tests from different technologies, the odds ratio of glaucomatous patients have increased considerably, reaching 689.7 with all the tests outside normal bounds, which have happened with 26 patients of this study. CONCLUSIONS: The Logistic Regression analysis confirmed that the abnormal tests of HRT and PAA have shown to be the highest reasons for glaucoma occurrence. The association of abnormal tests increased the odds ratio, especially when the HRT and PAA were out of normal bounds.

Associations with retinal nerve fiber layer measures in the EPIC-Norfolk Eye Study.

PURPOSE: To describe GDxVCC retinal nerve fiber layer (RNFL) measures and associations in a predominantly white British population. METHODS: The EPIC-Norfolk Eye Study is nested within a large multicenter cohort study, the European Prospective Investigation of Cancer. RNFL measurements were taken using the GDxVCC. Generalized estimating equation models were used to assess associations of RNFL measures with age, sex, body mass index (BMI), height, blood pressure, social class, education level, alcohol intake, smoking status, axial length, intraocular pressure, and lens status. Models were linearly adjusted for typical scan score to handle scans with atypical retardation. RESULTS: There were complete data from 11,030 eyes of 6309 participants with mean age 68 years (48-90 years). Older age (-1.53 µm/decade [95% confidence interval {CI} -1.73, -1.33], P < 0.001), male sex (-0.44 µm [95% CI -0.04, -0.84], P = 0.031), shorter axial length (-0.15 µm/mm [95% CI -0.02, -0.28], P = 0.024), and pseudophakia (-0.49 µm [95% CI -0.94, -0.04], P = 0.033) were associated with thinner RNFL after adjustment for possible confounders. Higher BMI was associated with a thinner RNFL in men only (-0.30 µm/5 kg/m(2) [95% CI -0.58, -0.02], P = 0.039). CONCLUSIONS: This analysis of associations with RNFL thickness in a largely healthy population may provide insight into the determinants of glaucoma, suggesting higher risk in those who are older, in men, and in men with a higher BMI.