Quantitative and qualitative spectral domain optical coherence tomography analysis of subretinal deposits in patients with acute central serous retinopathy.

PURPOSE: To perform qualitative and quantitative analyses of subretinal protein deposits (PDs), seen in acute central serous retinopathy (CSR) patients, using high-resolution spectral domain optical coherence tomography (SD-OCT), in order to investigate whether the present PDs have any significant impact on best corrected visual acuity (BCVA). METHODS: Patients diagnosed with acute CSR were included. Using SD-OCT, the following distances/heights were measured: central total retinal thickness, central neurosensory retinal thickness, the vertical and horizontal length of subfoveal subretinal fluid and subfoveal thickness of the PD layer, if present and could be measured. RESULTS: Thirty-eight patients with acute CSR were included. A significant correlation was found between the subfoveal thickness of the PD layer and baseline/final visual acuities in the eyes (r = 0.60, p ≤ 0.001 and r = 0.45, p = 0.008, respectively). CONCLUSIONS: The thickness of subfoveal PDs at baseline appears to be an important parameter related to the BCVA and time of CSR resolution.

Abnormal fixation in individuals with age-related macular degeneration when viewing an image of a face.

PURPOSE: It has been reported that patients with macular disease have difficulties with face perception. Some of this difficulty may be caused by the sensory and perceptual consequences of using peripheral retina. However, strong correlations have not always been found between performance on face tasks and clinical measure of function. Based on the evidence of abnormal eye movements by patients with age-related macular degeneration (AMD), we explored whether abnormal fixation patterns occur when these patients view an image of a face. METHODS: An OPKO OCT/SLO was used to collect structural and functional data. For each subject, the structural location of disease was determined, and the locus and stability of fixation were quantified. A SLO movie of fundus movements was recorded while the subject viewed an image of a face. RESULTS: The number of fixations on internal (eyes, nose, and mouth) and external features were measured. A two-way repeated-measures analysis of variance found significant differences between the control and patient groups and among locations. A significant interaction between group and location was also found. Post hoc comparisons found a significantly greater proportion of fixations on external features for the AMD group than that in the control group. CONCLUSIONS: The observed patterns of fixations of our subjects with AMD were similar to those observed in other groups of patients who have difficulties with face perception. For example, individuals with social phobias, Williams syndrome, autism, schizophrenia, or prosopagnosia have altered face perceptions and also have a significantly greater proportion of fixations on external features of faces. Abnormal eye movement patterns and fixations may contribute to deficits in face perception in AMD patients.

The physics and psychophysics of microperimetry.

PURPOSE: To assess the influences of stimulus parameters (physics) on measures of visual field sensitivity (psychophysics). METHODS: Subjects' thresholds were measured on three different clinically available perimeters: the Humphrey Field Analyzer (HFA), the Nidek MP1 (MP1), and the Opko OCT/SLO (OSLO). On all machines, visual field testing was done with a 10-2 spatial distribution of test points, using Goldmann Size III and Size I stimuli, with a presentation time of 200 ms, and using a 4-2 threshold algorithm. RESULTS: All the MP1 and OSLO data fell below the values for the corresponding points on the HFA. For the Goldmann Size III target, the HFA median threshold was 33 dB, whereas the MP1 median threshold was 19 dB and the OLSO, 18 dB. Using the increment intensity values at each dB level for each microperimeter, the data were converted to equivalent HFA dB. Using this conversion, the smallest increment displayed in the MP1 (1.27 cd/m) was equivalent to 34 HFA dB, and the brightest increment displayed by the MP1 was 14 HFA dB (127 cd/m). The smallest increment displayed in the OSLO (1.56 cd/m) was equivalent to 33.1 HFA dB, and the brightest increment displayed by the OSLO was 13.6 HFA dB (137 cd/m). There was good correspondence among these results when compared using equivalent increment threshold units. However, discrepancies in our findings made us acutely aware of the importance of evaluating the consequences of design choices made by the manufacturers. CONCLUSIONS: The findings underscore the need for users to check their assumptions about what the equipment is doing and to always evaluate the psychophysical consequences of the stimuli that are used by a particular instrument.

Initial report of quantification of retinal blood flow velocity in normal human subjects using the Retinal Functional Imager (RFI).

The Retinal Functional Imager (RFI) is a novel method for assessing retinal blood flow (RBF) velocity. The purpose of this study was to evaluate RBF velocities in normal human retinas using the RFI. RBF velocity measurements were performed in normal subjects using the RFI (Optical Imaging Ltd., Rehovot, Israel) at the Retina Center of The New York Eye and Ear Infirmary, New York, USA. Using proprietary software processing, the characteristics of the RBF were visualized and measured. The study population comprised fifty-four eyes of 27 normal subjects (20 male and 34 female). The average arterial blood flow velocity was 4.6 ± 0.6 mm/s in males and 4.8 ± 0.7 mm/s in females (the difference was not statistically significant, p value = 0.27). The average venous blood flow velocity was 3.8 ± 0.5 mm/s in males and 3.6 ± 0.4 mm/s in females (the difference again was not statistically significant, p value = 0.11). The average arterial blood flow velocity was 4.8 ± 0.5 mm/s in the right eye and 4.6 ± 0.7 mm/s in the left eye. The average venous blood flow velocity was 3.7 ± 0.4 mm/s in the right eye and 3.6 ± 0.3 mm/s in the left eye. Venous and arterial blood flow velocities were found to be faster in the right eye than in the left eye in our sample, but the differences were not statistically significant (p value = 0.53 and 0.33, respectively). This is the first report of quantification of the RBF using the RFI. The RFI appears to be an effective tool in quantitative evaluations of RBF velocities. The values from the study constitute a normative database which can be used to evaluate and compare eyes with known or suspected pathology.

Drusen characteristics revealed by spectral-domain optical coherence tomography and their corresponding fundus autofluorescence appearance in dry age-related macular degeneration.

PURPOSE: To analyze the relationship between drusen morphology revealed by spectral-domain optical coherence tomography (SD-OCT) and corresponding fundus autofluorescence (FAF) features of the same drusen using the Heidelberg Retina Angiograph 2 (HRA2), in patients with dry age-related macular degeneration (AMD). METHODS: Dry AMD patients were imaged with SD-OCT and HRA2 on the same day. SD-OCT B scans were then precisely overlaid onto the HRA2 images, and the SD-OCT morphological characteristics of the drusen were correlated with the corresponding FAF appearance. The analyzed morphological features of the drusen included: size, status of the inner segment/outer segment (IS-OS) junctional layer above the drusen, shape of the drusen, internal reflectivity, homogeneity and presence of overlaying hyperreflective foci. The FAF characteristics of each druse were rated as hyperautofluorescent, hypoautofluorescent or normally autofluorescent. Spearman's correlation coefficient was used to analyze the correlation between the 2 primary outcomes: SD-OCT morphology of the drusen and their autofluorescent appearance. RESULTS: 431 drusen in 32 eyes of 16 dry AMD patients were evaluated. Of the 7 morphological characteristics assessed by SD-OCT, only drusen size and the status of the IS-OS layer above the drusen were strongly correlated with the autofluorescent appearance (r = 0.78, p < 0.001, and r = 0.58, p < 0.001, respectively). The strength of correlation with other features appeared less robust: homogeneity (r = 0.38; p = 0.001), shape (r = 0.29; p = 0.004), reflectivity (r = 0.28; p = 0.004) and presence of overlaying foci (r = 0.25; p = 0.12). CONCLUSIONS: Autofluorescent changes most strongly correlate with drusen size and disruption of the IS-OS layer and may be useful as an additional functional-morphological feature by which drusen and their impact upon overlying photoreceptors may be judged.

Qualitative spectral OCT/SLO analysis of drusen change in dry age-related macular degeneration patients treated with Copaxone.

PURPOSE: High-resolution spectral domain OCT/SLO (SD-OCT) has become an increasingly useful tool for differentiating drusen morphologic parameters such as shape, internal reflectivity, homogeneity, and presence of overlying hyperreflective foci. Our purpose was to evaluate which types of drusen may respond to Copaxone (glatiramer acetate) treatment of dry age-related macular degeneration (AMD) patients by shrinking or disappearing. METHODS: A prospective and interventional clinical trial of patients with dry AMD who received subcutaneous treatment with Copaxone or sham injections was conducted. SD-OCT images were used for analysis of drusen ultrastructure. Morphologic characteristics for specific drusen within the macular region were assessed with serial studies. Pre- and posttreatment statuses of drusen were compared. Main outcome measure was a change of drusen morphologic parameters in Copaxone-treated and sham-treated dry AMD patients between baseline and 12 weeks of treatment. RESULTS: Three hundred eleven drusen from 26 eyes of 14 dry AMD patients were evaluated. One hundred seventy-two drusen from 14 eyes (7 patients) of Copaxone-treated and 139 drusen from 12 eyes sham-treated (7 patients) were included. Overall, between baseline and 12-week visit, the percentage of drusen that disappeared/shrank in the Copaxone-treated group was 19.2% versus 6.5% in the sham-treated group (P = 0.13). The percentage of convex drusen that shrank or disappeared after 12 weeks of treatment was significantly higher in the Copaxone-treated group (27.8%) in comparison with the sham-treated group (6.8%) (P = 0.008). The difference between the groups was found to be statistically significant for drusen with low and medium internal reflectivity (P = 0.019 and P = 0.036, respectively). CONCLUSIONS: Convex shape and low/medium internal reflectivity were found to be favorable parameters in prediction of drusen reduction in the Copaxone-treated patients. This study represents a preliminary attempt to identify SD-OCT features of drusen that may predict susceptibility to Copaxone treatment and therefore help clinicians decide which patients to treat.

Inner segment-outer segment junctional layer integrity and corresponding retinal sensitivity in dry and wet forms of age-related macular degeneration.

PURPOSE: To investigate a relationship between the inner segment-outer segment (IS-OS) junctional layer integrity and the overlying retinal sensitivity assessed by Spectral OCT/SLO (spectral-domain optical coherence tomography) and microperimetry testing in patients with dry and wet forms of age-related macular degeneration (AMD). METHODS: Spectral-domain optical coherence tomography examination and microperimetry testing were performed in 55 eyes of 43 consecutive patients with AMD. Microperimetry maps were registered onto three-dimensional retinal topography maps, and point-to-point analysis of correlation between microperimetric retinal sensitivities and corresponding status of the underlying IS-OS junctional layer was performed. In addition, the analysis of correlation between the best-corrected visual acuity and the integrity of IS-OS layer in the center of the fovea also was performed. RESULTS: Retinal sensitivity was inversely and strongly correlated with the integrity of IS-OS layer in both dry and wet forms of AMD (correlation coefficient [r] = -0.75 [95% confidence interval, 0.49-0.88], P < 0.001, and -0.79 [95% confidence interval, 0.61-0.89], P < 0.001, respectively). The correlation between the best-corrected visual acuity and the integrity of IS-OS layer in the center of fovea was less significant (r = -0.58 [95% confidence interval, 0.19-0.79], P = 0.02, for dry AMD, and r = -0.6 [95% confidence interval, 0.32-0.78], P = 0.015, for wet AMD). CONCLUSION: Retinal sensitivity consistently correlated with the status of underlying IS-OS junctional layer in both dry and wet forms of AMD. Loss of IS-OS layer is significantly associated with poor retinal sensitivity, assessed by microperimetry. Compared with visual acuity, functional testing with microperimetry appears to more consistently correlate with changes in the outer retina, such as IS-OS junctional integrity, especially, in patients with wet AMD.

Acquired senile retinoschisis of the peripheral retina imaged by spectral domain optical coherence tomography: a case report.

PURPOSE: We report spectral domain optical coherence tomography findings of the peripheral retina in a patient with senile (acquired) retinoschisis. METHODS: This is an observational case report. Spectral domain optical coherence tomography was performed to image the peripheral retina at the area of retinoschisis in a 70-year-old man with bilateral inferonasal elevated peripheral retinal lesions. Since the lesions were not entirely transparent and smooth, and demonstrated a certain degree of mobility, the diagnosis of retinal detachment could not be excluded. RESULTS: Spectral domain optical coherence tomography scans obtained at the margin of the lesions demonstrated attached retina with a characteristic splitting of the neurosensory retina at the outer plexiform layer and cystic changes in the inner retina. CONCLUSIONS: Spectral domain optical coherence tomography can assist in the diagnosis of senile (acquired) retinoschisis, particularly in cases where retinal detachment cannot be excluded on clinical examination alone.

Combined three-dimensional spectral OCT/SLO topography and Microperimetry: steps toward achieving functional spectral OCT/SLO.

AIMS: To investigate the combination of 3D optical coherence tomography (OCT) retinal thickness measurements and superimposed scanning laser ophthalmoscopy (SLO) microperimetry obtained using a Spectral OCT/SLO and to test the correlation between retinal thickness and retinal sensitivity in retinal diseases grouped according to anatomic locations. METHODS: Patients with various retinal diseases and subjects with normal fundi underwent microperimetry testing and imaging with the Spectral OCT/SLO. Based on the Spectral OCT/SLO findings, the participants were divided into 4 groups: patients with retinal thickening due to the outer retina pathology (group I); patients with retinal thickening due to the cystic changes observed in the inner retina (group II); patients with macular neurosensory retina thinning associated with geographic atrophy or underlying subretinal cicatricial changes (group III), and subjects with unremarkable fundus appearance and normal appearing retina on Spectral OCT/SLO (group IV). The primary outcome was the correlation coefficient (r) between Spectral OCT/SLO-measured macular thickness and microperimetry values. RESULTS: Correlations between retinal thickness and psychophysical thresholds were calculated for each patient, and these values were averaged within groups. The mean correlation values (Pearson product movement) were as follows: for group I (n = 21 eyes) r = 0.04; for group II (n = 24 eyes) r = -0.53; for group III (n = 16 eyes) r = 0.41, and for group IV (n = 15 eyes) r = 0.04. CONCLUSIONS: The combination of 3D OCT images and superimposed SLO microperimetry obtained by Spectral OCT/SLO demonstrated that thickening due to cystic changes of the inner retinal layers or thinning of the neurosensory retina on OCT correlated most significantly with decreases in psychophysical threshold sensitivities.

Correlation between retina blood flow velocity assessed by retinal function imager and retina thickness estimated by scanning laser ophthalmoscopy/optical coherence tomography.

PURPOSE: The purpose of this study was to evaluate the correlation between the retinal blood flow (RBF) assessed by the retinal functional imager (RFI) and central macular thickness/volume assessed by a spectral scanning laser ophthalmoscopy/optical coherence tomography (SLO-OCT) system. METHODS: Seventeen eyes of 14 consecutive patients with various ocular diseases were examined. Retinal blood circulation characteristics were measured using the RFI. Retinal thickness/volume parameters were obtained by SLO-OCT. Analysis of correlation between RBF velocity and SLO-OCT findings was performed. RESULTS: The analysis of the correlation between RBF and central retinal thickness/volume (5 x 5 mm grid pattern) showed a strong correlation between the average venous RBF velocity and central retinal volume. A linear relationship between the retinal blood velocity in veins and center, middle ring, outer ring and total central squares of macular volume [correlation coefficient 0.86 (p = 0.00001); 0.89 (p = 0.000001); 0.82 (p = 0.0004); 0.85 (p = 0.00001), respectively] has been observed. Arterial blood flow velocity did not correlate with thickness and with central retinal volume. CONCLUSIONS: Venous RBF, analyzed by the RFI, significantly correlated with the volume of the central retina, measured by SLO-OCT. Venous blood velocity increased linearly with the increase in the central retinal volume. In this small study, assessment using the RFI provides useful information and may contribute to the further understanding of hemodynamics in the retina blood vessels. The RFI shows promise of being able to analyze retinal hemodynamics noninvasively and may contribute to the further understanding of the relationship between retinal thickening and function.

Imaging through opaque corneas using anterior segment optical coherence tomography.

BACKGROUND AND OBJECTIVE: To investigate the capability of the prototype AC Cornea OCT (Ophthalmic Technologies Inc., Toronto, Ontario, Canada) for imaging eyes with opaque corneas. PATIENTS AND METHODS: More than 50 eyes of patients were included in the study. RESULTS: The density of opacification influenced the ability of OCT to reveal anterior segment details. Imaging was limited by shadows cast by abnormal pigmentation or vascularity within the cornea. However, the system's unique coronal perspective capability was helpful in revealing occult spatial relationships. CONCLUSIONS: The AC Cornea OCT is valuable for examining eyes with opaque corneas and provides cross-sectional and coronal views helpful in formulating specific management strategies.

Surface rendering of 3D ultrasound images in ophthalmology.

Surface rendering of three-dimensional ultrasound images is a novel way of imaging ophthalmic pathologies in vivo. The authors have evaluated surface rendering of three-dimensional ultrasound images in selected cases of opthalmic disease.

Wide-field handheld high frequency ultrasonography using a variable high frequency ultrasound system.

Wide-field handheld high frequency ultrasonography using a variable high frequency ultrasound system is an imaging modality in the frequency range of 35 to 50 MHz. Using a water bath immersion technique, high-resolution digital movies obtained from a variety of anterior segment ocular conditions were particularly helpful in establishing the diagnosis in each case. Images taken with the wide-field limbus-to-limbus mode provided a comprehensive picture of large and extensive lesions, whereas the focal mode was for small to medium lesions or specific areas of interest.

Optic nerve measurements by 3D ultrasound-based coronal "C-scan" imaging.

Twenty-three normal eyes were examined with the Intensity Profiling technique of 3D I-Scan and 52 normal eyes with the Automated technique of OTI-Scan 1000 ultrasound systems (Ophthalmic Technologies Inc., Toronto, Ontario, Canada). With the eye looking straight, the probe was applied on the temporal sclera. Scanning generated 3D image files. Coronal optic nerve measurements were obtained 3 mm behind the globe. The mean optic nerve sheath diameter was 4.8 mm (standard deviation = 0.6; range, 3.9 to 5.9 mm) with the Intensity Profiling technique, and 5.4 mm (standard deviation = 0.4; range, 4.4 to 6.0 mm) with the Automated technique. 3D ultrasound imaging can be used to obtain optic nerve measurements in vivo. Both the Intensity Profiling and the Automated techniques yielded measurements similar to current magnetic resonance imaging and computed tomography scan reports. Coronal "C-scan" sectioning can be used as a screening tool to measure optic nerve diameter prior to magnetic resonance imaging or computed tomography.