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.

Complex vectorial optics through gradient index lens cascades.

Graded index (GRIN) lenses are commonly used for compact imaging systems. It is not widely appreciated that the ion-exchange process that creates the rotationally symmetric GRIN lens index profile also causes a symmetric birefringence variation. This property is usually considered a nuisance, such that manufacturing processes are optimized to keep it to a minimum. Here, rather than avoiding this birefringence, we understand and harness it by using GRIN lenses in cascade with other optical components to enable extra functionality in commonplace GRIN lens systems. We show how birefringence in the GRIN cascades can generate vector vortex beams and foci, and how it can be used advantageously to improve axial resolution. Through using the birefringence for analysis, we show that the GRIN cascades form the basis of a new single-shot Müller matrix polarimeter with potential for endoscopic label-free cancer diagnostics. The versatility of these cascades opens up new technological directions.

Evaluation of intraretinal migration of retinal pigment epithelial cells in age-related macular degeneration using polarimetric imaging.

The purpose of the present study was to evaluate the intraretinal migration of the retinal pigment epithelium (RPE) cells in age-related macular degeneration (AMD) using polarimetry. We evaluated 155 eyes at various AMD stages. Depolarized light images were computed using a polarization-sensitive scanning laser ophthalmoscope (PS-SLO), and the degree of polarization uniformity was calculated using polarization-sensitive optical coherence tomography (OCT). Each polarimetry image was compared with the corresponding autofluorescence (AF) images at 488 nm (SW-AF) and at 787 nm (NIR-AF). Intraretinal RPE migration was defined by the presence of depolarization at intraretinal hyperreflective foci on PS-SLO and PS-OCT images, and by the presence of hyper-AF on both NIR-AF and SW-AF images. RPE migration was detected in 52 of 155 eyes (33.5%) and was observed in drusenoid pigment epithelial detachment (PED) and serous PED with significantly higher frequencies than in other groups (P = 0.015). The volume of the migrated RPE cluster in serous PED was significantly correlated with the volume of the PED (R2 = 0.26; P = 0.011). Overall, our results showed that intraretinal RPE migrations occurred in various AMD stages, and that they occurred more commonly in eyes with serous and drusenoid PED.

Linear polarization optimized Stokes polarimeter based on four-quadrant detector.

A four-quadrant detector (4QD) consists of four well-balanced detectors. We report on a Stokes polarimeter with optimal linear polarization measurements based on a 4QD. We turned the four intensity-detection channels into four polarization-analyzing channels by placing four polarizers and one quarter-wave plate in front of the individual detectors. An optimization method for the four polarization-analyzing channels is proposed to improve measurement accuracy. Considering applications in favor of linear polarization measurements instead of global optimization for all the possible states of polarization (SOP), we optimize the polarimeter first for the linear polarization components and then for the circular polarization component. The polarimeter is capable of simultaneous measurements of fast varying SOP with improved performance for the linear polarizations.

Comparison of Laser Scanning Diagnostic Devices for Early Glaucoma Detection.

BACKGROUND: To compare the diagnostic accuracy and to evaluate the correlation of optic nerve head and retinal nerve fiber layer thickness values between Fourier-Domain optical coherence tomography (FD-OCT), confocal scanning laser ophthalmoscopy (CSLO), and scanning laser polarimetry (SLP) for early glaucoma detection. PATIENTS AND METHODS: Ninety-three patients with early open-angle glaucoma, 58 patients with ocular hypertension, and 60 healthy control subjects were included in this observational, cross-sectional study. All study participants underwent FD-OCT (RTVue-100), CSLO (HRT3), and SLP (GDx VCC) imaging of the optic nerve head and the retinal nerve fiber layer. Area under the receiver operating characteristic curves (AUROC) and Bland-Altman analysis were performed. RESULTS: The parameters with the highest diagnostic accuracy were found for FD-OCT cup-to-disc ratio (AUROC=0.841), for SLP NFI (AUROC=0.835), and for CSLO cup-to-disc ratio (AUROC=0.789). Diagnostic accuracy of the best CSLO and SLP parameter was similar (P=0.259). There was a small statistically significant difference between the best CSLO and FD-OCT parameters for differentiating between glaucoma and healthy eyes (P=0.047). CONCLUSIONS: FD-OCT and SLP have a similarly good diagnostic ability to distinguish between early glaucoma and healthy subjects. The diagnostic accuracy of CSLO was comparable with SLP and marginally lower compared with FD-OCT.

[Screening method for angle closure and angle closure glaucoma using scanning laser polarimeter GDxVCC and photodynamic gonioscopy in a darkened room. One-year outcomes of systematic peripheral iridotomy]. / Méthode de dépistage du glaucome chronique par fermeture de l'angle basée sur l'utilisation systématique du GDxVCC et de la gonioscopie photodynamique. Résultats à un an d'une iridotomie systématique.

INTRODUCTION: Angle closure glaucoma, a recognized major world health issue disproportionately affecting women and Asians, is not often considered in our European populations, normotensive subjects, myopic patients, or subjects with a deep anterior chamber. Early diagnosis is worthwhile, as laser peripheral iridotomy (LPI) is an effective one-step treatment of the causal mechanism. PATIENTS AND METHODS: We have performed a retrospective study of patients who underwent an LPI, the indication for which was based on "photodynamic" gonioscopy in a darkened room showing iridotrabecular contact in darkness. Such photodynamic gonioscopy was motivated by the presence of even minute defects in the nerve fiber layer as seen on the GDxVCC or the presence of a Van Herick sign (narrow limbal anterior chamber depth). RESULTS: One hundred and three eyes of 103 patients underwent LPI and a minimum 1-year follow-up (mean follow-up almost 2 years). Mean age was 63.7±11.8 years, and women accounted for 63.1% of cases. The vast majority (78.6%) of patients had neither glaucoma nor ocular hypertension. There were 60.1% hyperopes and 39.9% myopes. Over half (57%) had a deep or a very deep anterior chamber. After LPI, there was immediate deepening of the limbal depth of the anterior chamber in 100% of cases. The aqueous humor that flowed forward was almost always viscous-looking. After 1 year, the IOP was 1.3mm Hg±2.4 lower (P<.001) (t test). All patients who had experienced morning headaches (44% of patients) were relieved of this symptom. GDxVCC after 1 year was clearly improved in 18% of cases, slightly improved in 20%, stable in 50%, slightly worse in 11% of cases, and clearly worse in 1%. Cases treated at an earlier stage had a better improvement in GDxVCC. DISCUSSION: Our study shows frequent chronic angle closure in our European population even with deep anterior chambers. Absence of a Van Herick sign does not rule out angle closure at night. A photodynamic gonioscopy with the Goldmann three-lens mirror (to avoid unintentional indentation with the small diameter lenses in these normotensive eyes) should be performed in a darkened room. LPI is an effective one-step treatment of the underlying cause, that is particularly beneficial if performed early.

Measuring retinal nerve fiber layer birefringence, retardation, and thickness using wide-field, high-speed polarization sensitive spectral domain OCT.

PURPOSE: We presented a novel polarization sensitive optical coherence tomography (PS-OCT) system for measuring retinal nerve fiber layer (RNFL) birefringence, retardation, and thickness, and report on the repeatability of acquiring these quantities. METHODS: A new PS-OCT system, measuring at 840 nm, was developed that supports scan angles of up to 40° × 40° with an A-scan rate of 70 kHz. To test the performance and reproducibility, we measured 10 eyes of 5 healthy human volunteers five times each. All volunteers were imaged further with scanning laser polarimetry (SLP). The obtained RNFL birefringence, retardation, and thickness maps were averaged, and standard deviation maps were calculated. For quantitative comparison between the new PS-OCT and SLP, a circumpapillary evaluation within 2 annular segments (superior and inferior to the optic disc) was performed. RESULTS: High quality RNFL birefringence, retardation, and thickness maps were obtained. Within the superior and inferior segments, the mean retardation for individual eyes ranged from 20° to 28.9° and 17.2° to 28.2°, respectively. The quadrant precision over the 5 consecutive measurements for each subject, calculated for the average retardation obtained within the superior and inferior quadrants ranged from 0.16° to 0.69°. The mean birefringence ranged from 0.106°/µm to 0.141°/µm superior and 0.101°/µm to 0.135°/µm inferior, with a quadrant precision of 0.001°/µm to 0.007°/µm. The mean RNFL thickness varied from 114 to 150 µm superior, and 111 to 140.9 µm inferior (quadrant precision ranged from 3.6 to 11.9 µm). CONCLUSIONS: The new PS-OCT system showed high image quality and reproducibility, and, therefore, might be a valuable tool for glaucoma diagnosis.

Out-of-plane Stokes imaging polarimeter for early skin cancer diagnosis.

Optimal treatment of skin cancer before it metastasizes critically depends on early diagnosis and treatment. Imaging spectroscopy and polarized remittance have been utilized in the past for diagnostic purposes, but valuable information can be also obtained from the analysis of skin roughness. For this purpose, we have developed an out-of-plane hemispherical Stokes imaging polarimeter designed to monitor potential skin neoplasia based on a roughness assessment of the epidermis. The system was utilized to study the rough surface scattering for wax samples and human skin. The scattering by rough skin-simulating phantoms showed behavior that is reasonably described by a facet scattering model. Clinical tests were conducted on patients grouped as follows: benign nevi, melanocytic nevus, melanoma, and normal skin. Images were captured and analyzed, and polarization properties are presented in terms of the principal angle of the polarization ellipse and the degree of polarization. In the former case, there is separation between different groups of patients for some incidence azimuth angles. In the latter, separation between different skin samples for various incidence azimuth angles is observed.

In vivo glucose monitoring using dual-wavelength polarimetry to overcome corneal birefringence in the presence of motion.

OBJECTIVE: Over the past 35 years considerable research has been performed toward the investigation of noninvasive and minimally invasive glucose monitoring techniques. Optical polarimetry is one noninvasive technique that has shown promise as a means to ascertain blood glucose levels through measuring the glucose concentrations in the anterior chamber of the eye. However, one of the key limitations to the use of optical polarimetry as a means to noninvasively measure glucose levels is the presence of sample noise caused by motion-induced time-varying corneal birefringence. RESEARCH DESIGN AND METHODS: In this article our group presents, for the first time, results that show dual-wavelength polarimetry can be used to accurately detect glucose concentrations in the presence of motion-induced birefringence in vivo using New Zealand White rabbits. RESULTS: In total, nine animal studies (three New Zealand White rabbits across three separate days) were conducted. Using the dual-wavelength optical polarimetric approach, in vivo, an overall mean average relative difference of 4.49% (11.66 mg/dL) was achieved with 100% Zone A+B hits on a Clarke error grid, including 100% falling in Zone A. CONCLUSIONS: The results indicate that dual-wavelength polarimetry can effectively be used to significantly reduce the noise due to time-varying corneal birefringence in vivo, allowing the accurate measurement of glucose concentration in the aqueous humor of the eye and correlating that with blood glucose.

Polarization-resolved second harmonic generation microscopy with a four-channel Stokes-polarimeter.

We developed a four-channel photon counting based Stokes-polarimeter for spatial characterization of polarization effects in second harmonic generation (SHG). We have implemented a calibration technique allowing quantitative measurement of polarization parameters, such as the degree of polarization (DOP), degree of linear polarization (DOLP), degree of circular polarization (DOCP), as well as anisotropy from the acquired Stokes parameters. The technique is used as contrast mechanism to characterize the polarization properties from two potassium dihydrogen phosphate (KDP) micro-crystals and collagen type-I in SHG microscopy.

[Application of optical coherence tomography in paediatric neuroophthalmology]. / Einsatzmöglichkeiten der optischen Kohärenztomografie bei der Diagnostik von Erkrankungen der Makula und des Nervus opticus bei Kindern.

Optical coherence tomography (OCT) is a non-invasive imaging technique which provides the possibility to record transpupillarily cross-sectional scans of the retina and the optic disc. The exact localisation and reproducibility of the scans are ensured by the combination with a scanning laser ophthalmoscope. The outcome of this is the possibility to collect additional morphological data for the diagnosis of neuroophthalmological diseases particularly in children. OCT data allow for the differentiation of macular diseases from optic nerve pathology in unexplained visual loss. Various forms of optic neuropathies can be distinguished and quantitatively characterised with regard to their severity and clinical course. Serial assessment of papilloedema or optic atrophy over time gives valuable objective information about the prognosis of the underlying disease and the therapy planning.

Ex-vivo characterization of human colon cancer by Mueller polarimetric imaging.

Cancerous and healthy human colon samples have been analyzed ex-vivo using a multispectral imaging Mueller polarimeter operated in the visible (from 500 to 700 nm) in a backscattering configuration with diffuse light illumination. Three samples of Liberkühn colon adenocarcinomas have been studied: common, mucinous and treated by radiochemotherapy. For each sample, several specific zones have been chosen, based on their visual staging and polarimetric responses, which have been correlated to the histology of the corresponding cuts. The most relevant polarimetric images are those quantifying the depolarization for incident linearly polarized light. The measured depolarization depends on several factors, namely the presence or absence of tumor, its exophytic (budding) or endophytic (penetrating) nature, its thickness (its degree of ulceration) and its level of penetration in deeper layers (submucosa, muscularis externa and serosa). The cellular density, the concentration of stroma, the presence or absence of mucus and the light penetration depth, which increases with wavelength, are also relevant parameters. Our data indicate that the tissues with the lowest and highest depolarizing powers are respectively mucus-free tumoral tissue with high cellular density and healthy serosa, while healthy submucosa, muscularis externa as well as mucinous tumor probably feature intermediate values. Moreover, the specimen coming from a patient treated successfully with radiochemotherapy exhibited a uniform polarimetric response typical of healthy tissue even in the initially pathological zone. These results demonstrate that multi-spectral Mueller imaging can provide useful contrasts to quickly stage human colon cancer ex-vivo and to distinguish between different histological variants of tumor.

Comparative study of retinal nerve fibre layer measurement by RTVue OCT and GDx VCC.

AIM: To evaluate the diagnostic performances and correlations of retinal nerve fibre layer (RNFL) thickness measured by RTVue OCT and GDx variable corneal compensation (VCC). METHODS: The total and regional RNFL thickness were measured by RTVue OCT and GDx VCC in 62 normal eyes and 72 glaucomatous eyes of Chinese subjects. The RNFL thickness profiles of normal and glaucomatous eyes by RTVue OCT are plotted. Correlations of RNFL thickness measured by RTVue OCT and GDx VCC were assessed using the Pearson correlation. The discriminating abilities of the two techniques for detection of glaucoma were compared by the area under the receiver operating characteristic curves (AUC). RESULTS: RTVue OCT demonstrated double hump patterns in the RNFL profiles. In both normal and glaucomatous subjects, the peaks were located in the superotemporal (ST) and inferotemporal (IT) regions, and the troughs were located at the nasal (NU+NL) and temporal (TU+TL) regions. Despite poor agreement, a high correlation (r=0.821) was found between the mean RNFL measurements by RTVue OCT and GDx VCC. For RTVue OCT, the highest AUCs were mean RNFL (AUC=0.914) and inferior mean RNFL (AUC=0.909). The nerve fibre indicator (AUC=0.856) and inferior RNFL (AUC=0.852) achieved the highest AUCs among all the GDx VCC measurements. The mean RNFL in RTVue OCT had the greatest AUC in the two devices. There was a significant difference in comparing the AUCs of the mean RNFL thickness obtained by RTVue OCT and GDx VCC (p=0.009). CONCLUSIONS: Although there were absolute value differences in RNFL thickness, a high correlation was observed between RTVue OCT and GDx VCC. RTVue OCT shows a reasonable ability to distinguish normal from glaucomatous eyes.

Detecting glaucomatous progression using GDx with variable and enhanced corneal compensation using Guided Progression Analysis.

OBJECTIVE: To compare detection of glaucoma progression with scanning laser polarimetry using two methods for corneal compensation. METHODS: Normal, glaucoma suspects and glaucoma patients with 36 months' follow-up meeting the eligibility criteria were prospectively enrolled. All subjects underwent complete eye exam, standard automated perimetry (SAP) and scanning laser polarimetry with variable and enhanced corneal compensation (GDxVCC, GDxECC). SAP progression was determined using the visual-field index (VFI). GDx progression was determined using Guided Progression Analysis software (GDxGPA) and was defined as a repeatable change on two consecutive scans compared with two baseline images using any of three strategies: ≥ 150 contiguous pixels on the image progression map (A), four or more adjacent segments on the Temporal Superior Nasal Inferior Temporal graph (B) or a significant change in slope of the summary parameter chart (C). Kappa statistics and logistic regression were used for the analysis. RESULTS: Thirteen normal, 30 glaucoma suspect and 25 glaucomatous eyes participating in the Advanced Imaging in Glaucoma Study were included. Progression was identified in six eyes (8.8%) using GDxVCC and in eight eyes (11.8%) using GDxECC. SAP progression was detected in seven (10.3%) eyes. Agreement among progression methods using GDxVCC and GDxECC was strongest for method C (kappa=0.57, p=0.002) compared with methods A (kappa=0.41, p=0.01) and B (kappa=0.41, p=0.01). The association between typical scan score (TSS) and overall or individual methods of progression was not significant using VCC or ECC (p>0.05). CONCLUSIONS: GDxGPA represents a novel approach for detection of glaucomatous progression. GDxVCC and GDxECC demonstrate moderate agreement.

Full analytical solution of Adapted Polarisation State Contrast Imaging.

We have earlier proposed a 2-channel imaging technique: Adapted Polarisation State Contrast Imaging (APSCI), which noticeably enhances the polarimetric contrast between an object and its background using fully polarised incident state adapted to the scene, such that the polarimetric responses of those regions are located as far as possible on the Poincaré sphere. We address here the full analytical and graphical analysis of the ensemble of solutions of specific incident states, by introducing 3-Distance Eigen Space and explain the underlying physical structure of APSCI and the effect of noise over the measurements.

Spectral-domain optical coherence tomography and scanning laser polarimetry in glaucoma diagnosis.

PURPOSE: To evaluate glaucoma diagnostic capability of the retinal nerve fiber layer (RNFL) imaging by spectral-domain optical coherence tomography (Cirrus OCT) and scanning laser polarimetry (GDx VCC). METHODS: We imaged 88 glaucomatous and 77 healthy eyes using both devices. Areas under the receiver-operating characteristic curves (area under the curves, AUCs) and sensitivities at fixed specificities of average, superior, and inferior RNFL thickness were compared. Likelihood ratios (LRs) and diagnostic agreement based on normative classifications yielded by both devices were determined. RESULTS: The best performing parameter was the nerve fiber indicator (NFI) in GDx VCC and inferior RNFL thickness in Cirrus OCT (AUC = 0.912, 0.961, P = 0.045). The AUCs of the Cirrus OCT were significantly higher than those of GDx VCC in all parameters. Most of the parameters in Cirrus OCT were more sensitive than GDx VCC in the detection of glaucoma at fixed specificity values. Cirrus OCT had an infinite LR with abnormal classification results in both average and superior RNFL thickness. There was good agreement between the two instruments with respect to abnormal classifications (kappa, 0.611-0.766) CONCLUSION: Both Cirrus OCT and GDx VCC RNFL measurements showed good glaucoma diagnostic capabilities. Cirrus OCT showed higher sensitivities than GDx VCC.

Full-range polarization-sensitive swept-source optical coherence tomography by simultaneous transversal and spectral modulation.

Polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) is used to measure three-dimensional phase-retardation images of birefringent biological tissue in vivo. PS-SS-OCT with continuous source polarization modulation is used to multiplex the incident states of polarization in the signal frequency of each A-scan. Although it offers the advantage of measurement speed that is as high as that of standard SS-OCT, its disadvantage is low axial measurement range. To overcome this drawback, we employed the B-M-mode scan (BM-scan) method, which removes complex conjugate ambiguity by applying phase modulation along the transversal scanning direction. Since polarization modulation and BM-scan are applied in different scanning directions, these methods can be combined to make the optimum use of both full range and polarization-sensitive imaging. Phase fluctuations that cause measurement failure were numerically canceled before demodulating the B-scan oriented modulation. After removing complex conjugate artifacts, the axial measurement range was 5.35 mm, and the signal-to-conjugate ratio was 40.5 dB. We demonstrated retinal imaging using the PS-SS-OCT system with a frequency-swept laser at a center wavelength of 1064 nm and an axial resolution of 11.4 microm in tissue. Full-range polarization-sensitive retinal images showed characteristic birefringence of fibrous tissues such as retinal nerve fiber, sclera, and lamina cribrosa.

Real-time, closed-loop dual-wavelength optical polarimetry for glucose monitoring.

The development of a real-time, dual-wavelength optical polarimetric system to ultimately probe the aqueous humor glucose concentrations as a means of noninvasive diabetic glucose monitoring is the long-term goal of this research. The key impact of the work is the development of an approach for the reduction of the time-variant corneal birefringence due to motion artifact, which is still a limiting factor preventing the realization of such a device. Our dual-wavelength approach utilizes real-time, closed-loop feedback that employs a classical three-term feedback controller and efficiently reduces the effect of motion artifact that appears as a common noise source for both wavelengths. In vitro results are shown for the open-loop system, and although the dual-wavelength system helps to reduce the noise, it is shown that closed-loop control is necessary to bring the noise down to a sufficient level for physiological monitoring. Specifically, in vitro measurement results with the closed-loop dual-wavelength approach demonstrate a sensitivity of 12.8 mg/dl across the physiologic glucose range in the presence of time-variant test cell birefringence. Overall, it is shown that this polarimetric system has the potential to be used as a noninvasive measure of glucose for diabetes.

In vivo characterization of human pigmented lesions by degree of linear polarization image maps using incident linearly polarized light.

BACKGROUND AND OBJECTIVE: Melanoma is the most serious form of skin cancer and often appears as an evolving multicolored skin growth. It is well documented that pre-existing atypical or dysplastic nevi can evolve into a melanoma. The development of an in vivo imaging system to characterize benign and malignant nevi has been emphasized to aid in early detection of melanoma. The goal of this study is to utilize a novel Stokes polarimetry imaging (SPI) system for the characterization of pigmented lesions, and to evaluate the SPI system in comparison to dermoscopy and histology images. STUDY DESIGN/MATERIALS AND METHODS: Linearly polarized light with varying incident polarization angles (IPA) illuminated various types of pigmented lesions. The melanocytic nesting patterns of pigmented lesions were characterized by constructing the degree-of-linear-polarization (DOLP) image map with comparison to dermoscopy and histology. The incident polarized light was filtered by visible filters for spectral imaging and incident deeply penetrating red light was used to correlate the SPI image with histopathological examination. RESULTS: The DOLP images with varying IPA at different visible wavelengths were used to characterize various kinds of pigmented lesions by showing subsurface melanocytic nesting distribution as well as morphological information with better resolution and contrast. In correlation with dermoscopy and histology, various defining features such as compound, junctional, lentiginous, reticular, globular patterns of melanocytic nests were identified. CONCLUSION: When imaging pigmented melanocytic lesions, the SPI system with varying IPA at the red light wavelength can better define the melanocytic nesting patterns in both the dermal epidermal junction and the dermis. The SPI system has the potential to be an effective in vivo method of detecting pre-malignant nevi and melanoma.

Ability of different optical imaging devices to discriminate between healthy and glaucomatous eyes.

We compared the ability to discriminate between healthy and glaucomatous eyes of three optical imaging devices in 140 eyes from 140 subjects. No statistically significant differences were found among the AUCs of these parameters. However, AUCs were significantly higher in OCT and HRT parameters than most of GDx VCC ones. Thus, structural parameters assessed by the optical imaging devices are useful to discriminate glaucomatous damage, but showed no significant difference among the best parameters from HRT, OCT or GDx VCC.