Ophthalmic surgery, lasers & imaging : the official journal of the International Society for Imaging in the Eye
A case of X-linked retinoschisis with anatomic and functional issues correlated by a constellatio... more A case of X-linked retinoschisis with anatomic and functional issues correlated by a constellation of methods, including spectral-domain optical coherence tomography, microperimeter, electroretinography, and multifocal electroretinography, is described. This case highlights the importance of microperimetry in the presence of normal or subtle abnormalities in full-field electroretinography. The ability of spectral-domain optical coherence tomography in diagnosis and follow-up in cases with X-linked retinoschisis is demonstrated.
To evaluate the retinal sensitivity and fixation characteristics in participants with diabetes me... more To evaluate the retinal sensitivity and fixation characteristics in participants with diabetes mellitus, using the microperimeter (MP-1) and to correlate the MP-1 values with the severity of diabetic retinopathy (DR). We performed complete ophthalmic examinations, including best-corrected visual acuity, slit-lamp examination, indirect ophthalmoscopy, and microperimetry (central 20° of macula) on 210 eyes of 160 participants. Participants included healthy individuals, individuals with diabetes but no retinopathy, and individuals with different stages of DR. The mean age of participants was (mean ± SD) 49.83 ± 7.43 years for healthy individuals, 53.20 ± 5.7 years for participants with diabetes but no retinopathy, and 55.39 ± 7.81 years for participants with DR. Retinal sensitivity was significantly (P = 0.001) decreased with severity of DR. The mean foveal sensitivity (retinal sensitivity in the central 2°) was 16.68 ± 2.13 dB in healthy individuals, 14.73 ± 3.64 dB in participants wi...
To investigate the reproducibility of anterior segment angle (ACA) metrics measurements in normal... more To investigate the reproducibility of anterior segment angle (ACA) metrics measurements in normal subjects on Cirrus spectral domain optical coherence tomography (SD-OCT). 40 eyes from 20 healthy, normal subjects underwent anterior segment imaging using a Cirrus SD-OCT. For each eye, 2 acquisitions of 5-line raster scans were performed perpendicularly on the inferior (270 degrees) angle. The Schwalbe's line-angle opening distance (SL-AOD) and Schwalbe's line-trabecular-iris space area (SL-TISA) measurements were performed by masked certified reading center graders using customized grading software. Intra-acquisition, intergrader, and intragrader reproducibility of SL-AOD and SL-TISA measurements were evaluated by intraclass correlation coefficients (ICC), Bland-Altman plots, and computation of mean percent difference (MPD) and coefficient of variability (CV). The mean SL-AOD (average of 2 acquisitions) was 0.75 mm (range, 0.32 mm to 1.39 mm); SL-TISA was 0.28 mm (range, 0.082 mm to 0.569 mm). The repeatability of Cirrus SD-OCT was excellent for both SL-AOD (MPD 4.74%, CV=0.92, ICC=0.99) and SL-TISA (MPD 9.4%, CV=0.8, ICC=0.99). The intragrader reproducibility was high for SL-AOD (MPD 4.28%, CV=0.94, ICC=0.995) and SL-TISA (MPD 6.05%, CV=0.89, ICC=0.993). The inter-grader reproducibility was not as good but still excellent for both SL-AOD (MPD 15.47%, CV=0.95, ICC=0.94) and SL-TISA (MPD 19.43%, CV=0.99, ICC=0.93). Bland-Altman plots of all comparisons did not demonstrate any apparent bias, with similar repeatability at various SL-AOD and SL-TISA values. In our population of young healthy adults with normal eyes, there was excellent intra-acquisition, intragrader, and intergrader reproducibility for Schwalbe's line-based ACA metrics obtained from Cirrus SD-OCT images. These SD-OCT-derived measures may serve as reliable descriptors of angle morphometry for use in clinical trials and clinical practice.
To compare the optical coherence tomographic (OCT) correlates of two previously described angiogr... more To compare the optical coherence tomographic (OCT) correlates of two previously described angiographic subtypes of occult choroidal neovascularization (CNV). We retrospectively analyzed 17 consecutive patients with previously untreated occult CNV who underwent both fluorescein angiography (FA) and volume spectral domain (SD)-OCT imaging on the same visit. Planimetric grading was performed on the FA images by certified reading center graders to precisely outline the boundaries of the fibrovascular pigment epithelial detachment (FVPED) and/or late leakage of undetermined source (LLUS) components of occult CNV for each case. In the SD-OCT images, the outer retinal pigment epithelial (RPE) and inner choroidal boundaries were manually segmented on all B-scans to generate a PED thickness map. Fluorescein angiography images were manually registered with the OCT fundus image, and the PED thickness was correlated with the angiographic lesion component present at each corresponding point in the fundus. Point-to-point correlations revealed that PED thickness was significantly different in areas of FVPED versus areas of LLUS. Whereas the mean PED thickness in areas of FVPED was 196.1 ± 120.36 μm, it was only 38.42 ± 8.14 μm in areas of LLUS (P = 0.003). Normalized internal reflectivity in areas of FVPED was lower than in areas of LLUS (0.12 ± 0.11 vs. 0.24 ± 0.07; P = 0.03). The integrity or continuity of the overlying RPE band on OCT, however, did not appear to differ between areas of LLUS and FVPED (P = 0.33). Although LLUS and FVPED appear to be distinct angiographic subtypes of CNV, the major difference between the two is the height of the RPE elevation and the internal reflectivity, with areas of LLUS representing much shallower RPE elevations with brighter mean internal reflectivity.
To explore the correlation between outer retinal substructures and visual acuity in dry age-relat... more To explore the correlation between outer retinal substructures and visual acuity in dry age-related macular degeneration (AMD).
To establish the retinal sensitivity values in healthy Indians using microperimeter. In this pros... more To establish the retinal sensitivity values in healthy Indians using microperimeter. In this prospective study, 144 healthy volunteers were included. All the participants underwent a comprehensive ophthalmic examination including contrast sensitivity. Microperimetry was performed in the central 20° of the macula using 76 stimulus points to assess the retinal sensitivity, and the fixation characteristics in the study population were assessed. The mean age of the study sample was 43.08 ± 10.85 years (range: 25-69). Mean retinal sensitivity was 18.26 ± 0.99 dB. Males had significantly increased retinal sensitivity (18.34 vs. 18.17 dB, P = 0.03). The linear regression analysis revealed a 0.04 dB per year age-related decline in mean retinal sensitivity. Contrast sensitivity was significantly correlated with the mean retinal sensitivity (r = 0.432, P < 0.001). Fixation stability in the central 2° and 4° were 69% and 89%, respectively. Microperimeter is an ideal tool to assess the retinal sensitivity and the fixation behavior. These normative values could help in drawing a meaningful conclusion in various retinal pathologies.
To measure total retinal blood flow (TRBF) in normal, healthy Chinese Americans by using semi-aut... more To measure total retinal blood flow (TRBF) in normal, healthy Chinese Americans by using semi-automated analysis of Doppler Fourier-domain optical coherence tomography (FD-OCT) scans. Two hundred sixty-six normal, healthy Chinese-American participants (266 eyes) were enrolled from The Chinese American Eye Study. All participants underwent complete ophthalmic examination, including best-corrected visual acuity, indirect ophthalmoscopy, and Doppler FD-OCT imaging, using the circumpapillary double circular scan protocol. Total retinal blood flow and other vascular parameters (e.g., venous and arterial cross-sectional area and their velocities) were calculated by using Doppler OCT of Retinal Circulation software. Associations between TRBF and other clinical parameters were assessed by using bivariate correlations and linear regression. The mean age of study participants was 57.40 ± 5.60 (range, 50-82) years. The mean TRBF was 49.34 ± 10.08 (range, 27.17-78.08, 95% confidence interval: 2...
Ophthalmic surgery, lasers & imaging : the official journal of the International Society for Imaging in the Eye
A case of X-linked retinoschisis with anatomic and functional issues correlated by a constellatio... more A case of X-linked retinoschisis with anatomic and functional issues correlated by a constellation of methods, including spectral-domain optical coherence tomography, microperimeter, electroretinography, and multifocal electroretinography, is described. This case highlights the importance of microperimetry in the presence of normal or subtle abnormalities in full-field electroretinography. The ability of spectral-domain optical coherence tomography in diagnosis and follow-up in cases with X-linked retinoschisis is demonstrated.
To evaluate the retinal sensitivity and fixation characteristics in participants with diabetes me... more To evaluate the retinal sensitivity and fixation characteristics in participants with diabetes mellitus, using the microperimeter (MP-1) and to correlate the MP-1 values with the severity of diabetic retinopathy (DR). We performed complete ophthalmic examinations, including best-corrected visual acuity, slit-lamp examination, indirect ophthalmoscopy, and microperimetry (central 20° of macula) on 210 eyes of 160 participants. Participants included healthy individuals, individuals with diabetes but no retinopathy, and individuals with different stages of DR. The mean age of participants was (mean ± SD) 49.83 ± 7.43 years for healthy individuals, 53.20 ± 5.7 years for participants with diabetes but no retinopathy, and 55.39 ± 7.81 years for participants with DR. Retinal sensitivity was significantly (P = 0.001) decreased with severity of DR. The mean foveal sensitivity (retinal sensitivity in the central 2°) was 16.68 ± 2.13 dB in healthy individuals, 14.73 ± 3.64 dB in participants wi...
To investigate the reproducibility of anterior segment angle (ACA) metrics measurements in normal... more To investigate the reproducibility of anterior segment angle (ACA) metrics measurements in normal subjects on Cirrus spectral domain optical coherence tomography (SD-OCT). 40 eyes from 20 healthy, normal subjects underwent anterior segment imaging using a Cirrus SD-OCT. For each eye, 2 acquisitions of 5-line raster scans were performed perpendicularly on the inferior (270 degrees) angle. The Schwalbe's line-angle opening distance (SL-AOD) and Schwalbe's line-trabecular-iris space area (SL-TISA) measurements were performed by masked certified reading center graders using customized grading software. Intra-acquisition, intergrader, and intragrader reproducibility of SL-AOD and SL-TISA measurements were evaluated by intraclass correlation coefficients (ICC), Bland-Altman plots, and computation of mean percent difference (MPD) and coefficient of variability (CV). The mean SL-AOD (average of 2 acquisitions) was 0.75 mm (range, 0.32 mm to 1.39 mm); SL-TISA was 0.28 mm (range, 0.082 mm to 0.569 mm). The repeatability of Cirrus SD-OCT was excellent for both SL-AOD (MPD 4.74%, CV=0.92, ICC=0.99) and SL-TISA (MPD 9.4%, CV=0.8, ICC=0.99). The intragrader reproducibility was high for SL-AOD (MPD 4.28%, CV=0.94, ICC=0.995) and SL-TISA (MPD 6.05%, CV=0.89, ICC=0.993). The inter-grader reproducibility was not as good but still excellent for both SL-AOD (MPD 15.47%, CV=0.95, ICC=0.94) and SL-TISA (MPD 19.43%, CV=0.99, ICC=0.93). Bland-Altman plots of all comparisons did not demonstrate any apparent bias, with similar repeatability at various SL-AOD and SL-TISA values. In our population of young healthy adults with normal eyes, there was excellent intra-acquisition, intragrader, and intergrader reproducibility for Schwalbe's line-based ACA metrics obtained from Cirrus SD-OCT images. These SD-OCT-derived measures may serve as reliable descriptors of angle morphometry for use in clinical trials and clinical practice.
To compare the optical coherence tomographic (OCT) correlates of two previously described angiogr... more To compare the optical coherence tomographic (OCT) correlates of two previously described angiographic subtypes of occult choroidal neovascularization (CNV). We retrospectively analyzed 17 consecutive patients with previously untreated occult CNV who underwent both fluorescein angiography (FA) and volume spectral domain (SD)-OCT imaging on the same visit. Planimetric grading was performed on the FA images by certified reading center graders to precisely outline the boundaries of the fibrovascular pigment epithelial detachment (FVPED) and/or late leakage of undetermined source (LLUS) components of occult CNV for each case. In the SD-OCT images, the outer retinal pigment epithelial (RPE) and inner choroidal boundaries were manually segmented on all B-scans to generate a PED thickness map. Fluorescein angiography images were manually registered with the OCT fundus image, and the PED thickness was correlated with the angiographic lesion component present at each corresponding point in the fundus. Point-to-point correlations revealed that PED thickness was significantly different in areas of FVPED versus areas of LLUS. Whereas the mean PED thickness in areas of FVPED was 196.1 ± 120.36 μm, it was only 38.42 ± 8.14 μm in areas of LLUS (P = 0.003). Normalized internal reflectivity in areas of FVPED was lower than in areas of LLUS (0.12 ± 0.11 vs. 0.24 ± 0.07; P = 0.03). The integrity or continuity of the overlying RPE band on OCT, however, did not appear to differ between areas of LLUS and FVPED (P = 0.33). Although LLUS and FVPED appear to be distinct angiographic subtypes of CNV, the major difference between the two is the height of the RPE elevation and the internal reflectivity, with areas of LLUS representing much shallower RPE elevations with brighter mean internal reflectivity.
To explore the correlation between outer retinal substructures and visual acuity in dry age-relat... more To explore the correlation between outer retinal substructures and visual acuity in dry age-related macular degeneration (AMD).
To establish the retinal sensitivity values in healthy Indians using microperimeter. In this pros... more To establish the retinal sensitivity values in healthy Indians using microperimeter. In this prospective study, 144 healthy volunteers were included. All the participants underwent a comprehensive ophthalmic examination including contrast sensitivity. Microperimetry was performed in the central 20° of the macula using 76 stimulus points to assess the retinal sensitivity, and the fixation characteristics in the study population were assessed. The mean age of the study sample was 43.08 ± 10.85 years (range: 25-69). Mean retinal sensitivity was 18.26 ± 0.99 dB. Males had significantly increased retinal sensitivity (18.34 vs. 18.17 dB, P = 0.03). The linear regression analysis revealed a 0.04 dB per year age-related decline in mean retinal sensitivity. Contrast sensitivity was significantly correlated with the mean retinal sensitivity (r = 0.432, P < 0.001). Fixation stability in the central 2° and 4° were 69% and 89%, respectively. Microperimeter is an ideal tool to assess the retinal sensitivity and the fixation behavior. These normative values could help in drawing a meaningful conclusion in various retinal pathologies.
To measure total retinal blood flow (TRBF) in normal, healthy Chinese Americans by using semi-aut... more To measure total retinal blood flow (TRBF) in normal, healthy Chinese Americans by using semi-automated analysis of Doppler Fourier-domain optical coherence tomography (FD-OCT) scans. Two hundred sixty-six normal, healthy Chinese-American participants (266 eyes) were enrolled from The Chinese American Eye Study. All participants underwent complete ophthalmic examination, including best-corrected visual acuity, indirect ophthalmoscopy, and Doppler FD-OCT imaging, using the circumpapillary double circular scan protocol. Total retinal blood flow and other vascular parameters (e.g., venous and arterial cross-sectional area and their velocities) were calculated by using Doppler OCT of Retinal Circulation software. Associations between TRBF and other clinical parameters were assessed by using bivariate correlations and linear regression. The mean age of study participants was 57.40 ± 5.60 (range, 50-82) years. The mean TRBF was 49.34 ± 10.08 (range, 27.17-78.08, 95% confidence interval: 2...
Uploads
Papers by Muneeswar Nittala