Posterior Pole Asymmetry Analysis Research Articles

Posterior Pole Asymmetry Analysis as a Diagnostic Tool in Glaucoma Suspects: An Electrophysiological Approach.

Spectral domain optical coherence tomography (SD-OCT) with posterior pole asymmetry analysis (PPAA) provides a mapping of posterior pole retinal thickness with asymmetry analysis between hemispheres of each eye. We investigated whether these structural abnormalities were correlated with functional retinal ganglion cell (RGC) loss, quantified by steady state pattern electroretinogram (ssPERG), in glaucoma suspects (GS). Twenty GS (34 eyes) were enrolled in a prospective study at the Manhattan Eye, Ear, and Throat Hospital. All subjects underwent ophthalmological examination, including Humphrey visual field, Spectralis Glaucoma Module Premium Edition (GMPE) SD-OCT PPAA, and ssPERG testing. The ability of ssPERG parameters (Magnitude [Mag, µv], MagnitudeD [MagD, µv], and MagD/Mag ratio) to predict PPAA thickness (total, superior, and inferior thickness, [µm]) was tested via adjusted multivariate linear regression analysis. Mag explained 8% of variance in total PPAA change (F(1,29)=6.33, B=6.86, 95% CI: 1.29-12.44, p=0.018), 8% in superior PPAA change (F(1,29)=5.57, B=6.92, 95% CI: 0.92-12.92, p=0.025), and 7.1% in inferior PPAA change (F(1,29)=5.83, B=6.80, 95% CI: 1.04-12.56, p=0.022). Similarly, MagD explained 9.7% of variance in total PPAA change (F(1,29)=8.09, B=6.47, 95% CI: 1.82-11.13, p=0.008), 10% in superior PPAA change (F(1,29)=7.33, B=6.63, 95% CI: 1.62-11.63, p=0.011), and 8.5% in inferior PPAA change (F(1,29)=7.25, B=6.36, 95% CI: 1.53-11.18, p=0.012). MagD/Mag ratio and PPAA were not significantly associated. To the best of our knowledge, this is the first study demonstrating a positive relationship between RGC dysfunction and retinal thickness changes between the superior and inferior hemispheres. The detection of asymmetrical structural loss, combined with functional RGC assessment using ssPERG, may be an informative tool for early glaucoma diagnosis.

Analysis of optical coherence tomography of the optic nerve head and of the retinal macular area in multiple sclerosis patients

BACKGROUND: Multiple sclerosis is a chronic autoimmune demyelinating disease of the central nervous system. Early diagnosis of the disease is extremely important for the just-in-time start of specific therapy. Optical coherence tomography (OCT) of the optic nerve head and retina can become an early marker of the neurodegenerative process in multiple sclerosis.
 AIM: To determine OCT-changes in the retinal nerve fiber layer (RNFL) thickness and retinal thickness in the macular area being most specific for multiple sclerosis.
 MATERIALS AND METHODS: 197 patients were examined, the study group consisted of 136 patients (274 eyes) with an established diagnosis of multiple sclerosis and the disease duration of at least 6 months. The control group included 61 healthy people (122 eyes). All patients underwent a standard ophthalmological examination, OCT was performed on Spectralis OCT (Heidelberg Engineering, Germany) using 2 scanning protocols: ONH-RC-Scan (Optic Nerve Head-Radial Circle Scan) and PPAA (Posterior Pole Asymmetry Analysis)
 RESULTS: Only 11 patients (8.1%) had a history of retrobulbar neuritis, the best corrected visual acuity was 0.7 and higher in 83 (81%) patients with multiple sclerosis, while the optic nerve head and retinal nerve fiber layer OCT-changes typical for multiple sclerosis were found in 118 patients (87%). The most prominent thinning of the retinal nerve fiber layer in group with multiple sclerosis was revealed in the temporal part of the optic nerve head (59.9 14.8 in the study group versus 76.6 12.0 in the control group; p 0.001), the least thinning was in the nasal half (66.6 14.3 in the study group versus 69.3 12.4 in the control group; p = 0.013). The retina in the macular area in multiple sclerosis patients was thinned over the entire area, the most significant changes were in the Outer Nasal 7 zone (303.3 20.4 in the study group versus 324.3 10.0 in the control group; p 0.001). Cluster analysis found 6 new retinal zones for mapping the macular area using the scanning protocol PPAA. In order to determine the prognostic value of the obtained zones, a logistic regression model was constructed, which with a sensitivity of 87.1% and a specificity of 81.6% allows concluding on the probability of having multiple sclerosis.
 CONCLUSION: OCT data using the proposed mapping of the macular area with the mathematical model analysis could be used to diagnose specific optic nerve atrophy, to reveal typical thinning of the retinal nerve fiber layer associated with multiple sclerosis, and in the long run, to become an additional criterion for establishing the diagnosis of multiple sclerosis.

Posterior Pole Asymmetry Analysis in the Children with Anisometropia.

Objectives:The objectives of the study were to investigate the inter and intraocular differences in posterior pole asymmetry analysis (PPAA) with optical coherence tomography (OCT) in anisometropia, to examine the relationship between the presence of anisometropia and amblyopia and retinal thickness.Methods:Patients between ages of 5 and 16 years with anisometropia who applied to our clinic were included in the study. Macular retinal thickness measurements were evaluated by PPAA using the posterior pole algorithm of the spectral domain-OCT device. Asymmetry was analyzed both as the difference between the right and left eyes and the difference between the superior, inferior, and mean retinal thicknesses of 64 separate quadrants in the same eye. Hemispheric and right-left eye asymmetry differences analyses were performed.Results:118 patients were included in the study(65 females and 53 males). Group 1 consisted of anisometropic patients (n=46), Group 2 consisted of anisometropic amblyopia patients (n=40), and Group 3 consisted of control group (n=32). The mean age of the patients was 9.72±5.6 years. The mean spherical equivalent difference between the two eyes of the patients was 1.7±0.6 D. When anisometropic eyes were compared with normal eyes, there was no significant difference between mean superior, inferior and total retinal thickness, and right-left eye asymmetry values (for all, p>0.05). In the asymmetry evaluation performed by counting the black boxes in the PPAA, a significant difference was found in the right-left asymmetry evaluation in anisometropic amblyopic eyes, in some quadrants and in the right-left asymmetry analysis (p<0.05).Conclusion:While no difference was found between anisometropic and normal eyes in the PPAA, there was differences in some quadrants in the anisometropic amblyopic group compared to the control group suggesting that there is an involvement in the peripheral quadrants of the macula, especially in treatment resistant amblyopic patients.

Comparison of Different Machine Learning Classifiers for Glaucoma Diagnosis Based on Spectralis OCT.

Early detection is important in glaucoma management. By using optical coherence tomography (OCT), the subtle structural changes caused by glaucoma can be detected. Though OCT provided abundant parameters for comprehensive information, clinicians may be confused once the results conflict. Machine learning classifiers (MLCs) are good tools for considering numerous parameters and generating reliable diagnoses in glaucoma practice. Here we aim to compare different MLCs based on Spectralis OCT parameters, including circumpapillary retinal nerve fiber layer (cRNFL) thickness, Bruch’s membrane opening-minimum rim width (BMO-MRW), Early Treatment Diabetes Retinopathy Study (ETDRS) macular thickness, and posterior pole asymmetry analysis (PPAA), in discriminating normal from glaucomatous eyes. Five MLCs were proposed, namely conditional inference trees (CIT), logistic model tree (LMT), C5.0 decision tree, random forest (RF), and extreme gradient boosting (XGBoost). Logistic regression (LGR) was used as a benchmark for comparison. RF was shown to be the best model. Ganglion cell layer measurements were the most important predictors in early glaucoma detection and cRNFL measurements were more important as the glaucoma severity increased. The global, temporal, inferior, superotemporal, and inferotemporal sites were relatively influential locations among all parameters. Clinicians should cautiously integrate the Spectralis OCT results into the entire clinical picture when diagnosing glaucoma.

Posterior pole retinal thickness distribution pattern in keratoconus.

To evaluate the pattern of retinal thickness distribution in patients with keratoconus (KCN) and its correlation with disease severity. For this cross-sectional cohort study, the study subjects with documented keratoconus and normal eyes were prospectively enrolled. All subjects had anterior segment (Pentacam HR) and posterior segment (Spectralis) imaging. Posterior segment imaging by optical coherence tomography included the posterior pole asymmetry analysis map. Data were analyzed with multiple linear regression models and correlation tests to examine the mean and variance of the measured thickness of the retina and its distribution relative to the presence and severity of KCN. A total of 24 subjects with keratoconus (48 eyes) and 14 normal subjects (28 eyes) enrolled in this study. The posterior pole retinal thickness, both superior and inferior hemifields, as well as the overall retinal thickness in KCN patients was greater than the control group. There was a direct correlation between the overall retinal thickness of the posterior pole and the severity of KCN (R2 = 0.422, P < 0.001). However, the variability of the retinal thickness showed no difference between KCN-afflicted and healthy eyes. Although KCN is a disease of the anterior segment of the eye, we found an orderly increase in posterior pole retinal thickness that is correlated with the severity of disease in KCN eyes compared to control. These findings suggest that the retina may maintain some degree of plasticity to respond to the degraded optical system of the eye.

Macular Thickness Asymmetry Measurements in Relatives of Primary Open Angle Glaucoma Patients

Background: A family history of glaucoma was found to carry a relative risk of 2.1 times for being associated with at least possible primary open angle glaucoma (POAG) in middle aged and older individuals. Around half of all POAG patients have a positive family history and their first degree relatives have an approximately 9-fold increased risk of developing glaucoma. Objective: the aim of the present study was to demonstrate possible early macular alterations in young relatives of POAG patients using spectral domain optical coherence tomography (SD-OCT) posterior pole asymmetry analysis (PPAA) map. Patients and methods: in a prospective comparative study; 40 subjects were classified into 2 groups: group of young healthy relatives of POAG patients and another group of young healthy subjects as control. All participants had OCT of the PPAA, retinal nerve fiber layer (RNFL), ganglion cell complex (GCC) and hemi-field macular thickness. Results: There was no statistically significant difference between the relative and control group in aspect of RNFL, macular hemi-fields and PPAA measurements (P-value >0.05). Regarding GCC thickness, there were statistically significant differences between both groups in the superior, inferior and nasal thickness measurements. Conclusion: Young healthy relatives of POAG patients didn’t show any early glaucomatous damage when compared with controls except for GCC thickness which showed statistically significant decrease.

Macular Thickness Asymmetry Measurements in Relatives of Primary Open Angle Glaucoma Patients

Background: A family history of glaucoma was found to carry a relative risk of 2.1 times for being associated with at least possible primary open angle glaucoma (POAG) in middle aged and older individuals. Around half of all POAG patients have a positive family history and their first degree relatives have an approximately 9-fold increased risk of developing glaucoma. Objective: the aim of the present study was to demonstrate possible early macular alterations in young relatives of POAG patients using spectral domain optical coherence tomography (SD-OCT) posterior pole asymmetry analysis (PPAA) map. Patients and methods: in a prospective comparative study; 40 subjects were classified into 2 groups: group of young healthy relatives of POAG patients and another group of young healthy subjects as control. All participants had OCT of the PPAA, retinal nerve fiber layer (RNFL), ganglion cell complex (GCC) and hemi-field macular thickness. Results: There was no statistically significant difference between the relative and control group in aspect of RNFL, macular hemi-fields and PPAA measurements (P-value >0.05). Regarding GCC thickness, there were statistically significant differences between both groups in the superior, inferior and nasal thickness measurements. Conclusion: Young healthy relatives of POAG patients didn’t show any early glaucomatous damage when compared with controls except for GCC thickness which showed statistically significant decrease.

Diagnostic Accuracy of Spectral-Domain OCT Circumpapillary, Optic Nerve Head, and Macular Parameters in the Detection of Perimetric Glaucoma

To evaluate the diagnostic accuracy of circumpapillary retinal nerve fiber layer (cRNFL), optic nerve head, and macular parameters for the detection of glaucoma using Heidelberg Spectralis OCT (Heidelberg Engineering, Inc., Heidelberg, Germany). Cross-sectional study. Participants of the Northern Ireland Cohort for the Longitudinal Study of Ageing with a vertical cup-to-disc ratio of 0.7 or more, vertical cup-to-disc ratio asymmetry of 0.2 or more, vertical neuroretinal rim ratio of 0.1 or less, intraocular pressure of 25 mmHg or more, or a combination thereof were invited to the study. Participants underwent clinical examination by a masked glaucoma expert and full-threshold visual field testing to define glaucoma. Five index tests were performed: (1) standard cRNFL thickness, (2) macular Early Treatment Diabetic Retinopathy Study (ETDRS) scans, (3) macular posterior pole asymmetry analysis (PPAA) scans, (4) Bruch's membrane opening minimum rim width (BMO MRW), and (5) Glaucoma Module Premium Edition (GMPE) cRNFL Anatomic Positioning System (APS) scans. We analyzed the eye with more advanced disease per participant. Analysis of receiver operating characteristic (ROC) curve; area under the ROC curve (AUC); and partial AUC (pAUC) at specificity of 0.80 to 1, 0.90 to 1, and 0.95 to 1. Sensitivity at 0.95 specificity and specificity at 0.95 sensitivity were reported. Primary analysis included all available scans. One hundred twenty-eight eyes from 128 participants were enrolled (52 eyes with perimetric glaucoma and 76 eyes without glaucoma). One hundred thirteen standard cRNFL thickness scans; 107 GMPE cRNFL APS 3.5-mm, 4.1-mm, and 4.7-mm scans; 107 BMO-MRW scans; 98 ETDRS scans; and 97 PPAA scans were available. Standard cRNFL mean global thickness showed highest AUC (0.869; 95% confidence interval [CI], 0.800-0.938) and the highest pAUC at specificity of 0.80 to 1 (0.815; 95% CI, 0.742-0.887), at specificity of 0.90 to 1 (0.794; 95% CI, 0.713-0.875), and at specificity of 0.95 to 1 (0.765; 95% CI, 0.696-0.861). Standard cRNFL mean global thickness scans provided the highest sensitivity at 0.95 specificity (0.630), whereas ETDRS mGCL outer inferior sector provided the highest specificity at 0.95 sensitivity (0.522). Macular and optic nerve head OCT parameters were not better than cRNFL measurements to diagnose glaucoma in this population.

Posterior pole asymmetry analysis and retinal nerve fibre layer thickness measurements in primary angle-closure suspect patients

PurposeTo measure peripapillary retinal nerve fiber layer (RNFL) thickness and posterior pole retinal thickness in primary angle-closure suspects (PACS) by Spectral domain optical coherence tomography (SD-OCT) and to be compared with normal subjects.MethodsThirty five primary angle-closure suspect patients and thirty normal subjects were enrolled in this study. Peripapillary RNFL and posterior pole retinal thickness by posterior pole asymmetry analysis (PPAA) in SD-OCT were measured.ResultsNo significant difference was found in both groups on age, sex distribution, refractive error, intraocular pressure (IOP) and axial length. The PACS group exhibited significantly thinner macular retinal thickness and larger asymmetry on posterior pole region compared with the control group. Yet no significant difference of peripapillary RNFL parameters was found between PACS group and normal control group. A negative correlation was observed between the total retinal thickness on posterior pole region and age when all the PACS participants were analyzed.ConclusionsPosterior pole retinal thickness measurements obtained by Heidelberg Spectralis SD-OCT using PPAA showed significant thinner change in PACS group than healthy controls. Only age seemed to be an indicator in the occurrence of glaucomatous damage in PACS patients.

Normative posterior pole asymmetry analysis data in healthy Caucasian population.

The aim of this study is to evaluate the variability of central retinal thickness asymmetry in healthy Caucasian adults with the posterior pole asymmetry analysis to serve as a reference. In total, 404 eyes of 202 subjects who aged between 18 and 80 years, who had no ocular pathology, were included in this cross-sectional observational study. Retinal thickness maps with posterior pole asymmetry analysis mode were taken with the optical coherence tomography (SPECTRALIS SD-OCT; Heidelberg Engineering). Superior and inferior hemifields were divided into five zones resembling to the strategy in Glaucoma Hemifield Test. Mean retinal thickness in each of the five zones was compared with the thickness of the corresponding zone in each eye (paired-samples t-test), and differences in retinal thickness (DRT1-5) and ganglion cell layer thickness between reciprocal locations were measured. Differences in retinal thickness values of two eyes of each subject were also compared (independent-samples t-test). The intra-eye asymmetry was statistically significant in zones 4 and 5. The highest mean intraocular differences in retinal thickness were 5.8 µm (zone 5) in all eyes, 5.8 µm (zone 5) in the right eyes, and 5.9 µm (zones 4 and 5) in the left eyes. The only statistically significant interocular local differences in retinal thickness asymmetries were found in zone 3. The intraocular asymmetry in retinal thickness was found to be the lowest in zone 1. The differences of ganglion cell layer thickness (GCLTs) were not statistically significant. There were statistically significant physiological inter-eye asymmetry in zone 3 and intra-eye asymmetries in zones 4 and 5. These measurements must be considered during screening for glaucoma with posterior pole asymmetry analysis in the Caucasian population.

A new strategy to interpret OCT posterior pole asymmetry analysis for glaucoma diagnosis.

To detect early glaucoma by optical coherence tomography (OCT) posterior pole asymmetry analysis. Totally 39 eyes from 39 healthy subjects, 40 eyes from 40 mild glaucoma patients, 33 eyes from 33 moderate glaucoma patients and 41 eyes from severe glaucoma patients were included in this study. All subjects underwent posterior pole asymmetry analysis (PPAA) of OCT and the posterior pole area was divided into three zones. Means, standard deviations and 95% confidence intervals of each zone asymmetry in control group were assessed. Retina thickness asymmetry (RTA) of different stage of glaucoma were compared for each zone, and receiver operating characteristic (ROC) curves were made to test the efficacy of strategies using different zones to discriminate glaucomatous eyes from the healthy ones. In a healthy population, RTA of the centre zone showed the minimal mean value (3.085 µm), standard deviation (1.756), and the narrowest 95% confidence interval (from 2.360 to 3.810 µm). It was only in the center zone that RTA exhibited significant difference between control and moderate glaucoma group (P<0.01), as well as control and severe glaucoma group (P<0.00001). The strategy utilized in the center zone had the strongest diagnostic capability (zone 3 AUROC=0.816, P=0.0016) in comparison to that of the periphery area (zone 1 AUROC=0.675, P=0.0016; zone 2 AUROC=0.623, P=0.0197), the whole posterior pole involved interpreting strategy showed inferior diagnostic power than the centre zone dependent strategy (z=2.851, P=0.0044). Utilizing the posterior pole centre zone to interpret OCT PPAA results are more effective than making use of the whole posterior pole map.

Asymmetry of Retinal Nerve Fiber Layer and Posterior Pole Asymmetry Analysis Parameters of Spectral Domain Optical Coherence Tomography in Children

ABSTRACTPurpose: To determine inter- and intraocular differences in the retinal nerve fiber (RNFL) and posterior pole asymmetry analysis (PPAA) macular thickness parameters in children using spectral domain optical coherence tomography. Method: A prospective, cross-sectional study involving 126 subjects between the age group of 5–15 years received a standardized eye examination including spectral domain optical coherence tomography for retinal nerve fiber layer and macular thickness measurements. Asymmetry was calculated as the difference between the right and left eyes as well as the superior and inferior area of one randomly selected eye for each subject. Normal ranges were established as the 2.5 and the 97.5 percentiles. Correlation between the right and left eyes were assessed by intraclass correlation coefficients. Results: The difference in the average and superior RNFL between the right and the left eye was not statistically significant. The interocular 2.5 and 97.5 percentile limits for RNFL thickness and total PPAA macular thickness were –7.75 to 12.5 microns and –9 to 21 microns, respectively. The 2.5 and 97.5 percentile limits of the intraocular superior-inferior area difference for the RNFL thickness and PPAA macular thickness were –40 to 37 microns and –32 to 38 microns, respectively. A strong correlation for all parameters between the right and the left eye was seen. Conclusion: The normal interocular RNFL and PPAA macular thickness asymmetry should not exceed 12.5 microns and 21 microns, respectively. Similar intraocular limits for superior-inferior asymmetry should not exceed 40 and 38 microns, respectively.

Detection of preperimetric glaucoma using Bruch membrane opening, neural canal and posterior pole asymmetry analysis of optical coherence tomography.

We analysed retinal nerve fibre layer (RNFL) defects in eyes with normal circumpapillary RNFL (cpRNFL) thickness using posterior pole asymmetry analysis (PPAA) and investigated the parameters of Bruch membrane opening (BMO) and neural canals using enhanced depth imaging spectral domain optical coherence tomography (EDI-SDOCT). A total of 112 preperimetric glaucomatous eyes of 92 patients were examined to obtain cpRNFL thickness using SD-OCT. Posterior pole asymmetry analysis (PPAA) and central cross-sectional images of the optic nerve head (ONH) were obtained using EDI-SDOCT. Minimal and horizontal distances between the BMO and ONH surfaces (BMOM, BMOH) and the terminal of retinal pigment epithelium (RPE) and ONH surfaces (RPEM, RPEH) were measured. The distribution of the absolute black cells in PPAA was more concentrated in eyes with “U”-shaped neural canals (p < 0.0001). The area under the receiver operating characteristic curve of the ratio of RPEM to RPEH (RPE-R, 0.771 ± 0.08) was significantly larger than the ratio of BMOM to BMOH (BMO-R, 0.719 ± 0.009) for PPAA results. A U-shaped neural canal, lower ratio of RPEM to RPEH, and lower ratio of BMOM to BMOH were considered early indicators of RNFL defects in preperimetric glaucomatous eyes with normal cpRNFL.

Intraeye retinal nerve fiber layer and macular thickness asymmetry measurements for the discrimination of primary open-angle glaucoma and normal tension glaucoma

PurposeThe aim of this study was to evaluate the diagnostic capability of intraeye retinal nerve fiber layer (RNFL) thickness and macular thickness (MT) asymmetry measurements for the discrimination of normal tension glaucoma (NTG) and primary open-angle glaucoma (POAG) using spectral domain optical coherence tomography (SD-OCT). MethodsA total of 90 subjects were enrolled including 30 consecutive healthy subjects, 30 consecutive subjects with POAG, and 30 consecutive subjects with NTG. RNFL thicknesses around the optic disc as well as MT measurements were taken with circular and radial SD-OCT scans. Intraeye retinal and MT asymmetry were calculated as the absolute difference between superior and inferior hemispheres of the eye using posterior pole asymmetry analysis protocol. Analysis of variance was used for comparison and areas under the receiver operating characteristic (AROC) were obtained for different parameters among the three diagnostic groups. ResultsThere was a significant difference in MT asymmetry for all comparison groups (normal-NTG, p<0.05; normal-POAG, p<0.001; and NTG-POAG, p<0.001). Intraeye retinal nerve fiber thickness asymmetry measurements were not different between the groups (normal-NTG, p<0.187; normal-POAG, p<0.056; and NTG-POAG, p<0.837). The area under ROC curves exceeded 0.800 for all the studied parameters, including the MT asymmetry except for intraeye RNFL thickness asymmetry which had the lowest AROC as well as the least sensitivity for identifying subjects with NTG from normal (AROC=0.626, sensitivity=30%); POAG from normal (AROC=0.644, sensitivity=37%) and NTG from POAG (AROC=0.533, sensitivity=13%). ConclusionThe intraeye MT asymmetry holds significant potential as a distinguishing parameter for NTG and POAG.

Diagnostic Power of Macular Retinal Thickness Analysis and Structure-Function Relationship in Glaucoma Diagnosis Using SPECTRALIS OCT

Aims: To evaluate the diagnostic power of the Posterior Pole Asymmetry Analysis (PPAA) from the SPECTRALIS OCT in glaucoma diagnosis and to define the correlation between the visual field sensitivity (VFS) and macular retinal thickness (MRT).Methods: 90 consecutive open-angle glaucoma patients and 23 healthy subjects were enrolled. All subjects underwent Visual Field test (Humphrey Field Analyzer, central 24-2 SITA-Standard) and SD-OCT volume scans (SPECTRALIS, Posterior Pole Asymmetry Analysis). The areas under the Receiving Operating Characteristic curve (AROC) were calculated to assess discriminating power for glaucoma, at first considering total MRT values and hemisphere MRT value and then quadrant MRT values from 16 square cells in a 8 x 8 posterior pole retinal thickness map that were averaged for a mean retinal thickness value. Structure function correlation was performed for total values, hemisphere values and for each quadrant compared to the matching central test points of the VF.Results: The AROCs ranged from 0.70 to 0.82 (p < 0.0001), with no significant differences between each other. The highest AROC observed was in inferior nasal quadrant. The VFS showed a strong correlation only with the corresponding MRT value s for quadrant analysis: Superior Temporal (r = 0.33, p = 0.0013), Superior Nasal (r = 0.43, p < 0.0001), Inferior Temporal (r = 0.57, p < 0.0001) and Inferior Nasal (r = 0.55, p < 0.0001).Conclusion: the quadrant analysis showed statistically significant structure-function correlations and may provide additional data for the diagnostic performance of SPECTRALIS OCT.

Posterior pole asymmetry analysis and retinal thickness measurements in young relatives of glaucoma patients

The presence of a family history of glaucoma is a known risk factor for primary open-angle glaucoma (POAG) in middle-aged and older individuals. In this study, our aim was to demonstrate possible early glaucomatous alterations in young first- and second-degree relatives of POAG patients by spectral-domain optical coherence tomography. A total of 104 participants (52 relatives of POAG patients and 52 healthy individuals) were recruited in this cross-sectional study. All the participants were between 17 years and 45 years of age. All eyes underwent testing with spectral-domain optical coherence tomography. Peripapillary retinal nerve fiber layer thickness, hemifield macular thickness, macular ganglion cell complex thickness, posterior pole asymmetry analysis, and retinal arteriolar caliber measurements were taken for comparison between the study and control groups. The mean peripapillary retinal nerve fiber layer thickness was 104.9 ± 8.8 μm in the study group and 105.6 ± 7.4 μm in the control group (p = 0.68). Although whole macular thickness measurements were higher in the control group when compared with the study group (p = 0.008), the macular ganglion cell complex thickness was similar in both groups (p = 0.87). The posterior pole asymmetry analysis revealed no statistically significant difference between the groups in the aspect of consecutive black squares (p = 0.79). The mean retinal arteriolar caliber was 85.9 ± 4.8 μm in the study group and 86.0 ± 5.0 μm in the control group (p = 0.90). In conclusion, young relatives of POAG patients do not show characteristic glaucomatous damage when compared with the controls.

Normal Value Ranges for Central Retinal Thickness Asymmetry in Healthy Caucasian Adults Measured by SPECTRALIS SD-OCT Posterior Pole Asymmetry Analysis.

To determine the normal variation in central retinal thickness asymmetry in healthy Caucasian adults using the posterior pole asymmetry analysis (PPAA) of a SPECTRALIS spectral-domain optical coherence tomography (SD-OCT) device. Healthy Caucasian individuals aged between 18 and 45 years with a visual acuity of minimum 20/20 and a spherical equivalent between -1.5 and +1.5 diopters were recruited. Retinal thickness and retinal nerve fiber layer thickness (RNFL) were using measured SPECTRALIS SD-OCT. Inter- and intraocular differences in central retinal thickness were calculated using the PPAA. The association between age, sex, and interocular asymmetry was evaluated by a linear model with Gaussian correlation structure. A total of 105 individuals, 30 men and 75 women, were studied. The mean age ± SD was 28.8 ± 7.87 years. The grand mean interocular retinal thickness asymmetry was 5.6 μm (95% confidence interval [CI]: 4.6-6.5) and the grand mean intraocular retinal thickness asymmetry was 8.3 μm (95% CI: 6.8-9.9) in the right eye and 8.4 μm (95% CI: 6.7-10.0) in the left eye. The highest local asymmetries were found in the nasal corners of macula were the posterior pole thickness map overlaps the temporal vascular arches. A slight general age and sex effect on the mean interocular retinal thickness asymmetry was found to be respectively 0.04 μm/year (95% CI: 0.02-0.06 μm) and 0.54 μm (95% CI: 0.19-0.88 μm) for men compared with women. Statistically significant physiological asymmetries in inter- and intraocular central retinal thickness exist. This must be considered when early signs of glaucoma or other pathologies are evaluated based on the retinal thickness asymmetry. (http://www.controlled-trials.com/isrctn/ number, ISRCTN09017572.).

Diagnostic accuracy of posterior pole asymmetry analysis parameters of spectralis optical coherence tomography in detecting early unilateral glaucoma.

Purpose:To report the diagnostic ability of posterior pole asymmetry analysis (PPAA) parameters of spectralis optical coherence tomography (OCT) in detecting early unilateral glaucoma.Methods:A prospective, cross-sectional study which included 80 eyes of 80 normal subjects and 76 eyes of 76 patients with unilateral early primary open-angle glaucoma by Hodapp-Anderson-Parrish classification. All subjects were of age more than 18 years, best-corrected visual acuity 20/40 or better, and a refractive error within ± 5 diopter (D) sphere and ± 3 D cylinder. Control subjects had a normal ocular examination, intraocular pressure (IOP) <22 mmHg, no past history of high IOP, no family history of glaucoma, normal optic disc morphology, and visual field in both eyes. One eye of the control subject was randomly included. All eyes underwent OCT for retinal nerve fiber layer (RNFL) analysis and PPAA. The number of continuous black squares was noted in the asymmetry analysis (right-left + hemisphere asymmetry). The area under curve (AUC) was calculated for all OCT parameters.Results:The best value for AUC for RNFL analysis was 0.858 for the inferotemporal quadrant thickness. This was similar to the best value for AUC for PPAA which was 0.833 for the inferior macular thickness parameter (P = 0.5). The AUC for the right-left and the hemisphere asymmetry part of PPAA was 0.427 and 0.499, respectively.Conclusion:The macular thickness PPAA parameters were equally good as the RNFL parameters. However, the asymmetry analysis parameters performed poorly and need further refinement before its use in early unilateral glaucoma diagnosis.

Macular asymmetry analysis in sighting ocular dominance

Sighting ocular dominance is the preference of one eye over the other in terms of sighting. In this study, our aim was to examine differences in interocular and intraocular macular thickness, interocular fovea-optic disc angle, and foveal blood vessel asymmetries associated with sighting ocular dominance. Ninety eyes of 45 healthy young adults were included in this prospective, cross-sectional, and comparative study. Sighting ocular dominance was determined by a hole-in-the-card test. Macular thickness measurements were taken and posterior pole asymmetry analysis conducted with spectral domain optical coherence tomography. The optic disc–fovea angle and visible foveal blood vessel counts were calculated by using the posterior pole retinal images of optical coherence tomography. The mean age of the participants was 27.3 (standard deviation [SD] 6.6) years. There were 20 males and 25 females. The mean total macular area thickness, and mean macular thickness of the superior and inferior hemispheres of the dominant and nondominant eyes were similar (p > 0.05). Macular asymmetry analysis revealed no statistically significant interocular difference (p > 0.05). In the dominant eyes, the mean optic disc–fovea angle was 5.24° (SD 1.77), whereas it was 5.49° (SD 2.58) in the nondominant eyes (p = 0.51). The number of visible blood vessels passing through the fovea was similar in the dominant and nondominant eyes (p > 0.05). These results suggested that interocular and intraocular macular thickness differences, interocular fovea–optic disc angle differences, and number of visible foveal blood vessels are not associated with sighting ocular dominance.

Hemifield patter electroretinogram and macular thickness asymmetry parameters in ocular hypertension patients

AbstractPurpose To assess which is the most sensitive and specific exam for detecting an early retinal ganglion cells (RGC) damage between hemifield test pattern electroretinogram (PERG HF) and the posterior pole asymmetry analysis with optical coherence tomography (OCT‐PPAA) in ocular hypertensive patients (OH).Methods Forty‐two OH patients (mean age of 56.0±5.6 yrs.) with an intraocular pressure (IOP)&gt;21mmHg and forty healthy controls (mean age of 55.2±6.4 yrs.) with IOP&lt;21mmHg were assessed. All patients had normal visual acuity, normal optic disc appearance and normal standard achromatic perimetric (SAP) indices. All subjects underwent an OCT‐PPAA with the OCT‐Spectralis and PERG HF examination. Data were analyzed with Wilcoxon test and Receiver Operating Characteristic (ROC) curve analysis taking p &lt; 0.05 as significant.Results We found that OH patients compared to healthy controls with full field PERG had a not significant decrease of the N95 wave amplitude (p&lt;0.097) with a significant increase of its peak‐time (103.88 ± 11.11 vs 92.78 ± 4.30 msec; p&lt;0.027). With PERG HF we found a significant intraeye asymmetry of the N95 wave (‐1.99±1.58 vs ‐0.67± 0.35 µVolt; p&lt;0.023). With OCT‐PPAA in OH patients we found a decrease in macular thickness but not a statistical significant intraeye hemispheric asymmetry (3.94± 2.89 vs 5.98±4.74 µ; p&lt;0.116). ROC curve analysis revealed a sensitivity of 80% and specificity of 87.6% for PERG HF whereas by using OCT‐PPAA we found a sensitivity of 70% and a specificity of 74%.Conclusion Our study shows that at the moment the PERG HF is the most sensitive and specific technique than OCT‐PPAA for detecting early RGC damages in eyes with ocular hypertension.