Cirrus High-definition Optical Coherence Tomography Research Articles

Automated Detection of Hemifield Difference across Horizontal Raphe on Ganglion Cell–Inner Plexiform Layer Thickness Map

A MATLAB-based (The MathWorks, Inc, Natick, MA) computer program (the ganglion cell-inner plexiform layer [GCIPL] hemifield test) for automated detection of GCIPL thickness difference across the horizontal raphe was developed, and its glaucoma diagnostic performance was assessed. Cross-sectional study. A total of 65 eyes of normal, healthy subjects along with 162 eyes of patients with glaucoma (79 preperimetric and 83 early perimetric). Cirrus high-definition optical coherence tomography (HD-OCT) (Carl Zeiss Meditec, Dublin, CA) was used to scan all of the subjects' macular and optic discs. A positive (i.e., "outside normal limits") GCIPL hemifield test result was declared if the following 3 conditions were all met: (1) The reference line (a horizontal line dividing the superior and inferior hemifields) is continuously detected for longer than one-half of the distance from the temporal inner elliptical annulus to the outer elliptical annulus; (2) the average GCIPL thickness difference within 10 pixels of the reference line, both above and below, is ≥5 μm; and (3) the average RGB color ranges of the 10 pixels above and below the reference line display blue in 1 hemifield and red/yellow/white in the other hemifield. Comparison of diagnostic ability using the areas under the receiver operating characteristic curves (AUCs). A positive GCIPL hemifield test result was observed more frequently in the glaucomatous eyes (74/79 preperimetric, 78/83 early perimetric) than in the normal eyes (1/65). In the preperimetric group, the AUC of the GCIPL hemifield test (0.967; sensitivity 94.94%, specificity 98.46%) was greater than that of the minimum GCIPL thickness (0.933), the inferotemporal GCIPL thickness (0.907), and the average GCIPL thickness (0.899) (P=0.09, 0.06, and 0.03, respectively). In the early perimetric group, the AUC of the GCIPL hemifield test (0.962; sensitivity 93.98%, specificity 96.46%) was greater than that of the inferotemporal GCIPL thickness (0.938), the minimum GCIPL thickness (0.919), and the average GCIPL thickness (0.912) (P=0.38, 0.17, and 0.11, respectively). For discrimination of early glaucomatous structural loss, most notably in preperimetric glaucoma cases, identification of the GCIPL thickness difference across the horizontal raphe was effective.

Reproducibility of peripapillary retinal nerve fiber layer thickness measurements with cirrus HD-OCT in glaucomatous eyes.

To assess the reproducibility of Cirrus high-definition optical coherence tomography (HD-OCT; Carl Zeiss Meditec, Dublin, CA, USA) for analysis of peripapillary retinal nerve fiber layer (RNFL) thickness in glaucomatous eyes. Forty-five eyes (one eye from each glaucomatous patient) were imaged with Cirrus HD-OCT. Each eye was imaged three times by two separate operators. Intraclass correlation coefficient (ICC), coefficient of variation (CV), and test-retest variability were evaluated for both intraobserver and interobsever measurements. In intraobserver measurements, the average RNFL thickness ICC was 0.983. CV and test-retest variability were 2.3% and 4.4 µm respectively. In quadrants ICC ranged from 0.886 to 0.956, the lowest associated with nasal quadrant and CV ranged from 3.6% to 7.7%. In interobsever measurements, the average RNFL thickness ICC was 0.979. CV and test-retest variability were 2.4% and 4.5 µm respectively. In quadrants ICC ranged from 0.886 to 0.957, the lowest associated with nasal quadrant and CV ranged from 3.8% to 8.6%. The reproducibility of Cirrus OCT for RNFL thickness is sufficiently good to be useful clinically as a measure of glaucoma progression.

Association of OCT derived drusen measurements with AMD associated-genotypic SNPs in Amish population.

Purpose: To investigate the association of optical coherence tomography (OCT)-derived drusen measures in Amish age-related macular degeneration (AMD) patients with known loci for macular degeneration. Methods: Members of the Old Order Amish community in Pennsylvania ages 50 and older were assessed for drusen area, volume and regions of retinal pigment epithelium (RPE) atrophy using a Cirrus High-Definition OCT. Measurements were obtained in the macula region within a central circle (CC) of 3 mm in diameter and a surrounding perifoveal ring (PR) of 3 to 5 mm in diameter using the Cirrus OCT RPE analysis software. Other demographic information, including age, gender and smoking status, were collected. Study subjects were further genotyped to determine their risk for the AMD-associated SNPs in the SYN3, LIPC, ARMS2, C3, CFB, CETP, CFI and CFH genes using TaqMan genotyping assays. The association of genotypes with OCT measures were assessed using linear trend p-values calculated from univariate and multivariate generalized linear models. Results: 432 eyes were included in the analysis. Multivariate analysis (adjusted by age, gender and smoking status) confirmed the known significant association between AMD and macular drusen with the number of CFH risk alleles for the drusen area (the area increased 0.12 mm2 for a risk allele increase, p < 0.01), drusen volume (the volume increased 0.01 mm3 for a risk allele increase, p ≤ 0.05) and the area of RPE atrophy (the area increased 0.43 mm2 for a risk allele increase, p = 0.003). SYN3 risk allele G is significantly associated with larger area PR (the area increased 0.09 mm2 for a risk allele increase, p = 0.03) and larger drusen volume in the central circle (the volume increased 0.01 mm3 for a risk allele increase, p = 0.04). Conclusion: Among the genotyped SNPs tested, the CFH risk genotype appears to play a major role in determining the drusen phenotype in the Amish AMD population.

Validity of the temporal-to-nasal macular ganglion cell-inner plexiform layer thickness ratio as a diagnostic parameter in early glaucoma.

To evaluate the diagnostic validity of temporal-to-nasal macular ganglion cell-inner plexiform layer thickness (TNM) ratio using Cirrus high definition-optical coherence tomography (HD-OCT) in patients with early glaucomatous damage. Enrolled participants included 130 normal controls, 50 patients with preperimetric glaucoma and 106 patients with early glaucoma. The patients with early glaucoma were classified into two subgroups according to the pattern of the visual field (VF) defects: the paracentral scotoma (PCS, n = 54) and the peripheral scotoma (PPS, n = 52). The thickness of the macular ganglion cell-inner plexiform layer (mGCIPL) and circumpapillary retinal nerve fibre layer (cpRNFL) was measured by Cirrus HD-OCT, and the average, superior and inferior TNM ratio was calculated. The average TNM ratio is a sum of superotemporal and inferotemporal mGCIPL thicknesses divided by the sum of superonasal and inferonasal mGCIPL thicknesses. Area under the receiver operating characteristic curve (AROC) of each parameter was compared between the groups. The parameter with the best AROC was the average TNM ratio and inferotemporal mGCIPL thickness in the PCS group and average cpRNFL thickness in the PPS group. The AROCs of the average, superior and inferior TNM ratio (p < 0.001, p = 0.007 and p < 0.001, respectively), minimum, average, inferotemporal and inferior mGCIPL thickness (p = 0.004, p = 0.003, p = 0.002 and p = 0.001, respectively) of the PCS were significantly higher than those of the PPS. However, the AROCs of the all cpRNFL thickness parameters did not show statistically significant differences between two subgroups. Asymmetry of temporal-to-nasal mGCIPL thickness could be an important parameter in the diagnosis of early glaucoma with paracentral VF defects.

Evaluation of the retinal ganglion cell layer thickness in healthy Turkish children.

To identify the distribution, variation, and determinants of ganglion cell-inner plexiform layer (GC-IPL) thickness in healthy Turkish children measured by high-definition optical coherence tomography (HD-OCT). This institutional study involved 296 eyes from 296 healthy children aged between 3 and 17 years. Each child underwent a dilated eye examination, cycloplegic refraction, and axial length measurement using Nidek AL-Scan optical biometer. Macular scan was used to measure the GC-IPL thickness, and peripapillary retinal nerve fiber layer (RNFL) thickness was measured using the HD-OCT (Cirrus HD-OCT). Right eye of each subject was selected for analysis. A total of 296 children (125 boys, 171 girls) were included in this study. The mean age of the children was 9.62±4.10 years (range, 3 to 17 y). The mean spherical equivalent was -0.09±1.49 D. The mean AL was 23.03±1.03 mm. The mean overall GC-IPL thickness was 83.44±5.52 μm and RNFL thickness was 96.91±10.21 μm. They were thicker than has been reported in adults. According to age-adjusted multiple regression analyses significant predictors of mean GC-IPL thickness were peripapillary RNFL thickness and AL (P<0.001). This study ensures a pediatric normative database of GC-IPL using spectral-domain OCT. This information may provide to diagnosis and monitoring of optic nerve diseases and glaucoma in children.

Effect of ocular magnification on macular measurements made using spectral domain optical coherence tomography.

Aim:The aim of the present study was to study the effect of ocular magnification on macular measurements made using spectral domain optical coherence tomography (OCT).Materials and Methods:One hundred and fifty-one subjects were included from the normative study of foveal morphology carried out at our hospital. Subjects underwent comprehensive eye examination and macular scanning using Cirrus high-definition OCT and axial length (AXL) measurement. Macular cube 512 × 128 scan protocol was used for scanning the macula. Automated measurements of the fovea namely foveal diameter, foveal slope (lateral measurements) and foveal depth (axial measurement) were taken. A correction factor for ocular magnification was done using the formula t = p × q × s, where “t” is the corrected measurement, “p” is the magnification of OCT, “q” is the ocular magnification, and “s” is the measurement on OCT without correction. The difference between corrected and uncorrected measurements was evaluated for statistical significance.Results:Mean AXL was 22.95 ± 0.78 mm. Refractive error ranged from −3D to +4D. Mean difference between measured and corrected foveal diameter, slope and depth was 166.05 ± 95.37 µm (P < 0.001), 0.81° ± 0.53° (P < 0.001) and 0.05 ± 0.49 µm (P = 0.178) respectively. AXL lesser than the OCT calibrated value of 24.46 mm showed an increased foveal diameter (r = 0.961, P < 0.001) and a reduced foveal slope (r = −0.863, P < 0.001) than the corrected value.Conclusion:Lateral measurements made on OCT varied with AXL s other than the OCT calibrated value of 24.46 mm. Therefore, to estimate the actual dimensions of a retinal lesion using OCT, especially lateral dimensions, we recommend correction for the ocular magnification factor.

Choroidal thickness measurement in healthy pediatric population using Cirrus HD optical coherence tomography.

To investigate the association between central choroidal thickness (CT), axial length (AL), age, gender, and refractive error in a healthy pediatric population using optical coherence tomography (OCT). This institutional study involved 137 healthy children (57 boys, 80 girls) aged between 4 and 18 years. Each child underwent a dilated eye examination, cycloplegic refraction, and AL measurement using a Nidek AL-Scan optical biometer. The central foveal thickness (CFT) and CT were measured using Cirrus high definition (HD)-OCT. The right eye of each subject was selected for analysis. The mean age of the children was 10.0 ± 4.7 years (range, 4-18 years). The mean spherical equivalent (SE) was -0.24 ± 1.24 diopters (D) (range, -2.00 D to +2.25 D). The mean AL was 23.1 ± 1.2 mm (range, 20-27 mm). The mean central CT was 388.2 ± 50.0 μm and was not correlated with age, gender, AL, or refractive error. The data provide a pediatric normative database of CT using enhanced depth imaging OCT. This information may be useful in the diagnosis and monitoring of retino-choroidal diseases in children.

Effects of cigarette smoking on choroidal and retinal thickness and ocular pulse amplitude

Background: In our study, we aimed to show the effects of smoking on choroidal thickness and ocular pulse amplitude. It is known that the anatomy and physiologic functions of the choroid is important in ocular diseases like glaucoma and age-related macular degeneration. Choroidal thickness is measured by the spectral domain optical coherence tomography (SD-OCT). The ocular pulse amplitude (OPA) is the difference between the systolic and diastolic intraocular pressure (IOP) and it is an index of choroidal perfusion.Design: This was a cross-sectional prospective observational study at the Turgut Ozal University Hospital setting.Participants: The test subjects were divided into two groups: the smokers group which consisted in 24 participants (20 male, 4 female) and the control group with 22 participants (16 male, 6 female).Methods: The participants underwent full ophthalmological examination including best-corrected visual acuity (BCVA), spherical equivalent (SE) values of refractive errors, intraocular pressure (IOP), ocular pulse amplitude (OPA), central corneal thickness (CCT), axial length (AL) and choroidal thickness. The IOP and the OPA were measured with the dynamic contour tonometer. The CCT and the AL were measured with the Nidek AL-Scan (Nidek Co., Ltd., Gamagori, Japan). The choroidal thickness was measured by the Cirrus high-definition optical coherence tomography (Cirrus Version 6.0; Carl Zeiss Meditec, Dublin, CA).Results: Gender did not differ significantly between the groups (p = 0.12). The age, SE, IOP, OPA, CCT and AL did not differ significantly in smokers and control groups (p = 0.12, p = 0.37, p = 0.54, p = 0.80, p = 0.56 and p = 0.82, respectively). The nasal, temporal, central retinal (p = 021, p = 021, p = 0.11) and nasal, temporal, central choroidal thicknesses (p = 0.80, p = 0.39, p = 0.75) did not differ significantly between smokers and control groups.Conclusions: We could not find a significant difference in OPA, retinal and choroidal thicknesses between smokers and non smokers. Further studies including histopathological changes in larger groups are needed to show the effect of smoking on choroidal thickness especially in patients with ocular diseases like age-related macular degeneration.

Relationship between retinal morphological findings and autoantibody profile in primary Sjögren's syndrome.

To investigate the morphological changes of the retina measured with the Cirrus high-definition optical coherence tomography in patients with primary Sjögren's syndrome (pSS). One hundred ninety six eyes of 196 patients with pSS and 200 eyes of 200 age and sex-matched normal controls were enrolled. Patients with pSS were divided into four subgroups based on their presence of autoantibodies (antinuclear antibody (ANA), anti-Ro/SSA, and anti-La/SSB). Peripapillary retinal nerve fiber layer (pRNFL) thickness, macular ganglion cell-inner plexiform layer (mGCIPL) thickness, and optic nerve head parameters were compared between groups. Compared with controls, a significant decrease was observed in the average, inferior, and temporal thicknesses of pRNFL and in the minimum, superotemporal, inferonasal, inferior, and inferotemporal thicknesses of mGCIPL of eyes with pSS (all P<0.05). In subgroup analyses, all eyes with positive tested autoantibodies [ANA(+), anti-Ro/SSA(+), anti-La/SSB(+)] showed a significant decrease of mGCIPL thicknesses, except for the superonasal portion, compared with eyes with any positivity for autoantibody (all P<0.05). There was a negative linear relationship between the number of positive autoantibodies and average and inferior pRNFL thicknesses or all mGCIPL parameters, except for the superonasal portion, with a Spearman correlation analysis in patients with pSS (all P<0.05). Compared with controls, eyes with pSS showed thinning of pRNFL and mGCIPL thicknesses. The degree of thinning correlated with increased numbers of the positive autoantibody.

Agreement of Retinal Nerve Fiber Layer Defect Location Between Red-Free Fundus Photography and Cirrus HD-OCT Maps

Purpose: To investigate the agreement of angular locations of retinal nerve fiber layer (RNFL) defect margins in glaucomatous eyes by using red-free fundus photographs and Cirrus high-definition optical coherence tomography (OCT) RNFL deviation and thickness maps.Methods: We examined 380 RNFL defects that showed clear margins in red-free fundus photographs. The OCT deviation and thickness maps were overlaid on the corresponding red-free fundus photographs. A reference line was drawn between the disc center and the macular center. Lines were also drawn between the optic disc center and the point where the RNFL defect margins crossed the OCT scan circle. The angle between the reference and defect-margin lines defined the angular location of the defect margin. Angular locations of proximal (nearest to the reference) and distal (farthest from the reference) RNFL defect margins on OCT deviation and thickness maps were compared to the locations on red-free fundus photographs.Results: The angular locations of proximal and distal RNFL defect margins on OCT thickness maps showed good agreement with red-free fundus photographs. However, OCT deviation maps showed greater angular locations for both proximal and distal RNFL defect margins compared with red-free fundus photographs, especially in eyes with higher myopia (p < 0.05).Conclusions: Red-free fundus photographs and OCT thickness maps showed good agreement for the RNFL defect margin identification. However, this was not the case for deviation maps, especially in myopic eyes. This finding should be considered when evaluating RNFL defects using OCT maps.

An investigation of lateral geniculate nucleus volume in patients with primary open-angle glaucoma using 7 tesla magnetic resonance imaging.

To investigate lateral geniculate nucleus (LGN) volume of primary open-angle glaucoma (POAG) patients compared with age- and sex-matched controls using ultra-high field 7.0-T magnetic resonance imaging (MRI). The study included 18 patients with POAG and 18 age- and sex-matched healthy volunteers. All subjects underwent imaging on a high-resolution 7.0-T MRI system. Bilateral LGNs were identified and manually delineated, and LGN volumes were compared. Peripapillary retinal nerve fiber layer (pRNFL) thickness, optic nerve head parameters (including optic disc size, rim area, and cup-to-disc ratio), and combined thickness of the ganglion cell layer and inner plexus layer (GC-IPL) were measured by Cirrus high-definition optical coherence tomography (OCT). Correlations between OCT parameters and LGN volume were investigated. Mean LGN volumes were significantly smaller in the POAG group than in the control group (right, glaucoma 83.97 mm(3) [SD ± 26.65] versus control 106.12 mm(3) [SD ± 24.32]; left, glaucoma 65.12 mm(3) [SD ± 29.41] versus control 92.70 mm(3) [SD ± 24.42], both P < 0.05). In the POAG group, average GC-IPL thickness was correlated with contralateral LGN volume (right LGN: r = 0.605, P = 0.008; left LGN: r = 0.471, P = 0.049). The correlation for right LGN volume remained significant after correction for multiple comparisons. However, there was no correlation between LGN volume and average pRNFL thickness or optic disc parameters in the POAG group. On high-resolution 7.0-T MRI, LGN volumes in POAG patients are significantly smaller than those of healthy subjects. Furthermore, in patients, LGN volume was found to be significantly correlated with GC-IPL thickness of the contralateral eye.

Macular Ganglion Cell Analysis for Early Detection of Glaucoma

To investigate the ability of Cirrus high-definition optical coherence tomography (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA) macular ganglion cell analysis (GCA) sector, deviation, and thickness maps to detect early glaucoma. Cross-sectional study. We enrolled 131 eyes with early glaucoma (mean deviation >-6.0 dB) and 132 age- and refractive error-matched healthy eyes. Macular GCA maps were obtained using Cirrus HD-OCT. The location, angular distance, and width of circumpapillary retinal nerve fiber layer (RNFL) defects were investigated by using red-free fundus photographs. The presence of a structural abnormality in the GCA map was defined as (1) yellow/red color codes in the sector map, (2) yellow/red pixels (>10) in the deviation map, and (3) blue areas in the thickness map. The prevalence of and factors associated with the presence or absence of abnormal GCA findings were assessed. Among the 131 glaucomatous eyes, 105 (80.2%), 115 (87.8%), and 104 (79.4%) showed structural abnormalities in the GCA sector, deviation, and thickness maps, respectively. The absence of abnormal findings in the GCA maps of glaucomatous eyes was associated with the presence of RNFL defects in the superior hemisphere, a greater angular distance between the fovea and the RNFL defect, a narrower width of the RNFL defect, less severe visual field defects, or an isolated peripheral nasal step (outside 10 degrees of fixation) (P<0.05). A greater angular distance of the RNFL defect remained significant in multivariate analyses (P<0.05). Among the 132 healthy eyes, 28 (21.2%), 37 (28.0%), and 20 (15.2%) had abnormal findings in the GCA sector, deviation, and thickness maps, respectively. The presence of abnormal GCA findings in healthy eyes was associated with a higher degree of myopic refractive error (P<0.05). Cirrus HD-OCT GCA maps showed a good ability to detect early glaucoma. However, GCA maps did not show abnormal findings in glaucomatous eyes when the angular distance between fovea and RNFL defect was great. These findings should be considered when diagnosing early glaucoma using GCA maps.

Quantitative Assessment of Retinal Nerve Fiber Layer Defect Depth Using Spectral-Domain Optical Coherence Tomography

To assess quantitatively the depth of retinal nerve fiber layer (RNFL) defects using a Cirrus high-definition (HD) optical coherence tomography (OCT)-derived RNFL thickness deviation map. Prospective, cross-sectional study. Three-hundred fifteen eyes with localized and diffuse RNFL defects of 315 glaucoma patients and 217 eyes of 217 healthy subjects. For the glaucoma subjects, the severity of the RNFL defect was graded on red-free fundus photographs by 2 observers using a standardized protocol with a 3-level grading system. The RNFL defect depth on the RNFL thickness deviation map was expressed as an RNFL defect depth percentage index (RDPI): 100×(1-[summation of thicknesses of RNFL defects {red or yellow superpixels}/summation of RNFL thicknesses of upper 95th percentile range of age-matched healthy subjects in areas corresponding to RNFL defects]). Retinal nerve fiber layer defect depth percentage index, average and segmental (4 quadrants and 12 clock-hour sectors) circumpapillary RNFL (cpRNFL) thicknesses according to the RNFL defect severity, and the area under the receiver operating characteristic curves (AUROCs) for various OCT parameters. The RDPIs increased with the increasing severity of the RNFL defect in both the superior and inferior hemifields (P <0.05, 1-way analysis of variance test with Bonferroni correction). The AUROCs of the RDPIs (0.969 and 0.975 in the superior and inferior hemifields, respectively) were larger than those of all of the cpRNFL thicknesses in discriminating the mild from the moderate RNFL defects (P <0.05). Meanwhile, in discriminating the moderate from the severe RNFL defects, the AUROCs of the RDPIs (0.961 and 0.891 in the superior and inferior hemifields, respectively) were larger than those of the cpRNFL thicknesses in all areas except the inferior quadrant and the 6-, 7-, and 11-o'clock sectors (P <0.05). The RDPI, a new parameter using a Cirrus HD OCT-derived RNFL thickness deviation map, can be a useful adjunct tool for objective quantification of RNFL defect depth. This parameter has an advantage over cpRNFL thickness in discriminating between mild and moderate RNFL defects, not in discriminating between moderate and severe defects.

Diagnostic Validity of Macular Ganglion Cell-Inner Plexiform Layer Thickness Deviation Map Algorithm Using Cirrus HD-OCT in Preperimetric and Early Glaucoma

To evaluate the diagnostic validity of macular ganglion cell-inner plexiform layer (mGCIPL) thickness deviation map algorithm using Cirrus high definition-optical coherence tomography to discriminate between normal controls and patients with preperimetric or early glaucoma. Seventy-two normal controls, 37 patients with preperimetric glaucoma and 70 patients with early glaucoma were enrolled. mGCIPL thickness and peripapillary retinal nerve fiber layer (pRNFL) thickness were measured by Cirrus high definition-optical coherence tomography. Areas showing abnormal color coding were obtained by customized Image J software calculating the number of abnormal superpixels at 1% and 5% level in each deviation map of measurements (GCIPL-DM1, GCIPL-DM5, RNFL-DM1, RNFL-DM5). The area under the receiver operating characteristic curve (AROC) of each parameter was calculated to provide diagnostic ability between normal controls and patients with preperimetric or early glaucoma. AROCs of the deviation map algorithms were higher than those of other parameters. Parameter with the best AROC was the GCIPL-DM5 (0.920 and 0.968) in both preperimetric and early glaucoma. The sensitivities of the GCIPL-DM5 at 80% and 95% specificities were 92% and 68% in preperimetric glaucoma and 98% and 90% in early glaucoma, respectively. Pairwise comparisons between AROCs of parameters from deviation map algorithms did not show statistically significant differences. mGCIPL thickness deviation map showed good diagnostic ability in detecting preperimetric and early glaucoma, and it was comparable with pRNFL thickness deviation map. Our findings suggest that it can be an important parameter in detecting subtle glaucomatous structural change.

Characterization of retinal nerve fiber layer thickness changes associated with Leber’s hereditary optic neuropathy by optical coherence tomography

In the present study, the changes in the retinal nerve fiber layer (RNFL) thickness associated with Leber’s hereditary optic neuropathy (LHON) were examined by Cirrus high definition-optical coherence tomography (OCT), and the correlation between the RNFL thickness and the best corrected visual acuity (BCVA) was evaluated. A cross-sectional study was performed. Sixty-eight eyes from patients with LHON and 30 eyes from healthy individuals were scanned. Affected eyes were divided into 5 groups according to disease duration: Group 1, ≤3 months; group 2, 4–6 months; group 3, 7–9 months; group 4, 10–12 months; and group 5, >12 months. The RNFL thickness of the temporal, superior, nasal and inferior quadrants and the 360° average were compared between the LHON groups and the control group. The eyes in groups 1 and 2 were observed to have a thicker RNFL in the superior, nasal and inferior quadrants and a higher 360°-average RNFL thickness compared with those of the control group (P<0.05), the RNFL was observed to be thinner in the temporal quadrant in groups 1 and 2. The eyes in groups 3 and 4 showed a thinner RNFL in the temporal (P=0.001), superior and inferior (both P<0.05) quadrants, and a lower 360°-average RNFL thickness as compared with controls (P=0.001). No significant correlation was identified between BCVA and RNFL thickness. RNFL thickness was observed to undergo a unique process from thickening to thinning in the patients with LHON. Changes in different quadrants occurred at different time periods and the BCVA was not found to be correlated with RNFL thickness.

Comparative Study of Macular Ganglion Cell–Inner Plexiform Layer and Peripapillary Retinal Nerve Fiber Layer Measurement: Structure–Function Analysis

We explored and compared the relationships between the visual field (VF) sensitivities assessed by standard automated perimetry (SAP), and the ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) thicknesses as measured by Cirrus high-definition optical coherence tomography (HD-OCT) in glaucomatous eyes. We enrolled 213 eyes of 213 patients with glaucoma. The thicknesses of the average/sectoral GCIPL and pRNFL were measured by Cirrus HD-OCT. The mean sensitivity (MS) of 24-2 SAP was recorded on decibel and 1/L scales. The topographic relationships between structure and function were investigated. Statistically significant correlations between the corresponding VF sensitivity and the macular GCIPL thickness were found in all GCIPL sectors. Among six GCIPL sectors, the strongest association was observed between superonasal center MS and inferotemporal GCIPL thickness. In comparative analysis, the association between the central cluster MS and average GCIPL thickness was significantly stronger than that of temporal pRNFL thickness using the decibel scale (P < 0.001). The association between regional VF sensitivities, and the inferior hemifield and inferior GCIPL thicknesses were significantly stronger than those of the corresponding pRNFL thickness using the decibel scale (P = 0.001 and 0.007). The average and sectoral GCIPL thicknesses determined by Cirrus HD-OCT were associated significantly with global and regional VF sensitivity in patients with glaucoma. The macular GCIPL thickness values may provide more valuable information than temporal pRNFL thickness values for understanding the structure-function relationships of the macular region.

Cirrus High-definition Optical Coherence Tomography Versus Spectral Optical Coherence Tomography/Scanning Laser Ophthalmoscopy in the Diagnosis of Glaucoma

Purpose: This study was performed to compare the positive predictive value of peripapillary retinal nerve fiber layer (RNFL) thickness measurements obtained using Cirrus high-definition optical coherence tomography (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA) and spectral OCT/scanning laser ophthalmoscopy (SLO) (OPKO/OTI, Miami, FL) in the diagnosis of glaucoma.Methods: A total of 50 eyes of 50 healthy subjects and 60 eyes of 60 subjects with glaucoma were included. All participants underwent RNFL thickness measurement using Cirrus HD-OCT and spectral OCT/SLO on the same day. Average, quadrant, clock-hour RNFL thicknesses, area under the receiver operating characteristic curve (AUC), and sensitivities at fixed specificities (80% and 95%) were calculated for comparison.Results: RNFL thickness as measured by spectral OCT/SLO was greater than that measured using Cirrus HD-OCT (p < 0.001). For both the Cirrus HD-OCT and spectral OCT/SLO, the parameter with the largest AUC was average RNFL thickness (0.954 and 0.944, respectively). The AUCs of RNFL thickness for the discrimination of glaucoma did not differ significantly between the devices (p > 0.05), with the exception of RNFL thickness in the nasal area (nasal quadrant, clock-hour sectors 3 and 4); in these areas, spectral OCL/SLO yielded greater AUCs than Cirrus HD-OCT (p < 0.05). Sensitivities varied similarly to AUCs.Conclusions: RNFL thicknesses measures using Cirrus HD-OCT and spectral OCT/SLO were not interchangeable. The utility of RNFL thickness measurements in the diagnosis of glaucoma was similar for both the devices.

Glaucoma Diagnostic Ability of Ganglion Cell–Inner Plexiform Layer Thickness Differs According to the Location of Visual Field Loss

To determine whether the ganglion cell-inner plexiform layer (GCIPL) or circumpapillary retinal nerve fiber layer (cpRNFL) is better at distinguishing eyes with early glaucoma from normal eyes on the basis of the the initial location of the visual field (VF) damage. Retrospective, observational study. Eighty-four patients with early glaucoma and 43 normal subjects were enrolled. The patients with glaucoma were subdivided into 2 groups according to the location of VF damage: (1) an isolated parafoveal scotoma (PFS, N= 42) within 12 points of a central 10 degrees in 1 hemifield or (2) an isolated peripheral nasal step (PNS, N= 42) within the nasal periphery outside 10 degrees of fixation in 1 hemifield. All patients underwent macular and optic disc scanning using Cirrus high-definition optical coherence tomography (Carl Zeiss Meditec, Dublin, CA). The GCIPL and cpRNFL thicknesses were compared between groups. Areas under the receiver operating characteristic curves (AUCs) were calculated. Comparison of diagnostic ability using AUCs. The average and minimum GCIPL of the PFS group were significantly thinner than those of the PNS group, whereas there was no significant difference in the average retinal nerve fiber layer (RNFL) thickness between the 2 groups. The AUCs of the average (0.962) and minimum GCIPL (0.973) thicknesses did not differ from that of the average RNFL thickness (0.972) for discriminating glaucomatous changes between normal and all glaucoma eyes (P =0.566 and 0.974, respectively). In the PFS group, the AUCs of the average (0.988) and minimum GCIPL (0.999) thicknesses were greater than that of the average RNFL thickness (0.961, P =0.307 and 0.125, respectively). However, the AUCs of the average (0.936) and minimum GCIPL (0.947) thicknesses were lower than that of the average RNFL thickness (0.984) in the PNS group (P =0.032 and 0.069, respectively). The GCIPL parameters were more valuable than the cpRNFL parameters for detecting glaucoma in eyes with parafoveal VF loss, and the cpRNFL parameters were better than the GCIPL parameters for detecting glaucoma in eyes with peripheral VF loss. Clinicians should know that the diagnostic capability of macular GCIPL parameters depends largely on the location of the VF loss.

Analysis of Choroidal Morphologic Features and Vasculature in Healthy Eyes Using Spectral-Domain Optical Coherence Tomography

To analyze the morphologic features and vasculature of the choroid in healthy eyes using spectral-domain (SD) optical coherence tomography (OCT). Cross-sectional retrospective review. Forty-two healthy subjects (42 eyes) with no ocular disease who underwent high-definition scanning with Cirrus high-definition OCT (Carl Zeiss Meditec, Inc., Dublin, CA) at the New England Eye Center, Boston, Massachusetts, between November 2009 and September 2010. The SD OCT images were evaluated for morphologic features of the choroid, including the shape of the choroid-scleral border, location of the thickest point of choroid, and regions of focal choroidal thinning. Total choroidal thickness and large choroidal vessel layer thickness were measured by 2 independent observers experienced in analyzing OCT images using the Cirrus linear measurement tool at the fovea, 750 μm nasal and temporal to the fovea. Custom software was used to calculate the ratio of choroidal stroma to the choroidal vessel lumen. Qualitative assessment of the choroidal morphologic features, quantitative analysis of choroidal vasculature, and use of novel automated software to determine the ratio of choroidal stromal area to the area of choroidal vessel lumen. The 42 subjects had a mean age of 51.6 years. All subjects (100%) had a so-called bowl or convex shape to the choroid-sclera junction, and the thickest point of the choroid was under the fovea in 88.0% of the subjects. The mean choroidal thickness was 256.8 ± 75.8 μm, mean thickness of the large choroidal vessel layer was 204.3 ± 65.9 μm, and that of the medium choroidal vessel layer-choriocapillaris layer was 52.9 ± 20.6 μm beneath the fovea. The ratio of large choroidal vessel layer thickness to the total choroidal thickness beneath the fovea was 0.7 ± 0.06. The software-generated ratio of choroidal stromal area to the choroidal vessel lumen area was 0.27 ± 0.08, suggesting that choroidal vessel lumen forms a greater proportion of the choroid than the choroidal stroma in healthy eyes. This is the first study to describe the morphologic features and vasculature of the choroid in healthy eyes from 1-line raster scans obtained using SD OCT. The method described holds promise and has immediate clinical usefulness in recognizing subtle changes in choroidal morphologic features and the role of choroidal angiopathy in various disease states that, in the future, may inform new treatment methods. Proprietary or commercial disclosure may be found after the references.

Morphological Change of Inner Retinal Layer on Spectral-Domain Optical Coherence Tomography following Macular Hole Surgery

Background/Aims: To investigate the morphological changes of the inner retinal layer by spectral-domain optical coherence tomography (OCT) after idiopathic full-thickness macular hole (MH) surgery. Methods: In a retrospective study, the authors evaluated 52 eyes of 49 patients with MH closed following vitrectomy. All patients were followed postoperatively for more than 6 months. Cross-sectional and retinal surface images were obtained using Cirrus high-definition OCT before and after surgery. In 24 of the 52 eyes, fundus autofluorescence (FAF) was analyzed. Results: The incidence of dissociated optic nerve fiber layer (DONFL) increased gradually over time after surgery. 57.7% had defects of only the retinal nerve fiber layer (RNFL) and 30.8% had defects in the inner plexiform layer at 6 months after surgery. Postoperative best-corrected visual acuity did not differ significantly based on the depth of the DONFL (p = 0.299). There were no changes in FAF in the area with DONFL. Conclusions: DONFL is characterized by progressive defects that are not limited to RNFL thickness. The healing process after vitrectomy for MH is not limited in the RNFL affecting deeper structural changes. Further investigations are required to evaluate the pathophysiological mechanism of inner retinal change after MH surgery.