Cirrus Spectral-domain Optical Coherence Tomography Research Articles

Anatomical compensation of retinal nerve fiber layer improves the detection of glaucoma between ethnicities.

The study aimed to evaluate the impact of compensating retinal nerve fiber layer (RNFL) thickness for demographic and anatomical factors on glaucoma detection in Chinese and Indian adults. A population-based study included 1995 healthy participants (1076 Chinese and 919 Indians) to construct a multivariable linear regression compensation model. This model was applied to 357 Chinese glaucoma patients, 357 healthy Chinese, and 357 healthy Indians using Cirrus spectral-domain optical coherence tomography (OCT). The compensated RNFL thickness considered age, refractive error, optic disc parameters, and retinal vessel density. Results showed that although the average RNFL thickness was significantly higher in Chinese participants compared to Indians, the compensation model reduced this difference to nonsignificance. Moreover, the compensation model significantly improved the area under the receiver operating characteristic curve (0.90 vs. 0.78; p<0.001), sensitivity (75% vs. 51%), and specificity (67% vs. 32%) in distinguishing Chinese glaucoma patients from healthy Indian individuals. The compensation model significantly enhanced the diagnostic accuracy of RNFL thickness in distinguishing glaucoma in the Chinese ethnic group compared to the OCT instrument's default values. These results suggest that modifying RNFL measurements based on individual characteristics can yield substantial benefits for glaucoma detection across ethnicities.

OCTess: AN OPTICAL CHARACTER RECOGNITION ALGORITHM FOR AUTOMATED DATA EXTRACTION OF SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY REPORTS.

Manual extraction of spectral domain optical coherence tomography (SD-OCT) reports is time and resource intensive. This study aimed to develop an optical character recognition (OCR) algorithm for automated data extraction from Cirrus SD-OCT macular cube reports. SD-OCT monocular macular cube reports (n = 675) were randomly selected from a single-center database of patients from 2020 to 2023. Image processing and bounding box operations were performed, and Tesseract (an OCR library) was used to develop the algorithm, OCTess. The algorithm was validated using a separate test data set. The long short-term memory deep learning version of Tesseract achieved the best performance. After reverifying all discrepancies between human and algorithmic data extractions, OCTess achieved accuracies of 100.00% and 99.98% in the training (n = 125) and testing (n = 550) datasets, while the human error rate was 1.11% (98.89% accuracy) and 0.49% (99.51% accuracy) in each, respectively. OCTess extracted data in 3.1 seconds, compared with 94.3 seconds per report for human evaluators. We developed an OCR and machine learning algorithm that extracted SD-OCT data with near-perfect accuracy, outperforming humans in both accuracy and efficiency. This algorithm can be used for efficient construction of large-scale SD-OCT data sets for researchers and clinicians.

Comparison of Cirrus spectral domain OCT with disc-macula distance to disc diameter ratio in diagnosing congenital optic nerve hypoplasia.

Diagnosis of congenital optic nerve hypoplasia (CONH) can be challenging in children or uncooperative individuals. Misdiagnosis can lead to inappropriate treatment; thus, it is important to identify an objective and reliable measurement. The purpose of this study was to evaluate whether Cirrus spectral domain optical coherence tomography (SD-OCT) is a valid test for diagnosing CONH by comparing it to the disc-macula distance to disc diameter (DM:DD) ratio. A total of 93 participants (64 controls and 29 CONH) underwent comprehensive eye examinations, fundus photography and Cirrus SD-OCT. Receiver operating characteristic (ROC) curves for the DM:DD ratio and OCT disc area were constructed for CONH and control eyes. Mean (±SD) OCT disc area was 1.46 (±0.42) mm2 and 1.89 (±0.38) mm2 for CONH and control eyes, respectively (p < 0.0001). The area under the curve for the DM:DD ratio was 0.97 (95% confidence interval: 0.91-0.99) and 0.79 for OCT disc area (95% confidence interval: 0.70-0.86), which were significantly different (p = 0.0005). The optimal cut-off value for OCT disc area was 1.66 mm2 (76% sensitivity, 70% specificity), while the optimal cut-off for DM:DD ratio was 3.10 (85% sensitivity and 95% specificity). The Cirrus SD-OCT showed a tendency to overestimate disc size, especially in cases with no light perception (NLP) or segmental CONH. Although the DM:DD ratio is superior to OCT in diagnosing CONH with a higher sensitivity and specificity, the ratio is subject to inter-examiner variability and can be challenging to obtain. We found the Cirrus SD-OCT to be a valid objective test for diagnosing CONH. Caution is advised when using SD-OCT in segmental CONH or in an eye with NLP. We suggest 1.66 mm2 as the optimal cut-off value for Cirrus SD-OCT disc area to differentiate a hypoplastic from a normal optic disc.

Influence of Multiple Anti-VEGF Injections on Retinal Nerve Fiber Layer and Ganglion Cell-Inner Plexiform Layer Thickness in Patients with Exudative Age-Related Macular Degeneration.

Backgrounds and Objectives: To analyze the influence of multiple anti-VEGF intravitreal injections for exudative age-related macular degeneration on the thickness of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GC + IPL) using spectral domain optical coherence tomography (SD-OCT). Materials and Methods: A prospective interventional study of consecutive patients treated with intravitreal bevacizumab (IVB) was performed. Average and sectorial values of RNFL and GC + IPL thickness were recorded using Cirrus SD-OCT at 0, 6, 12, and 24 months. Patients suffering from any ocular disease that could affect RNFL or GC + IPL thickness were excluded. Results: A total of 135 patients (70 women and 65 men, aged 65 ± 15 years) were included. The average number of injections per patient was 12.4 ± 2.4. Average RNFL and GC + IPL thickness prior to the first injection (87.6 ± 12.2 and 47.2 ± 15.5 respectively), and after 24-month follow-up (86.2 ± 12.6 and 46.7 ± 11.9 respectively) did not differ significantly (p &gt; 0.05). There was a significant decrease in GC2, GC5 segments, and minimum GC + IPL thickness. Conclusion: Repeated anti-VEGF treatment did not cause significant changes in the thickness of RNFL and GC + IPL layers over a period of 24 months. The detected decrease in GC2 and GC5 sectors, as well as in minimum GC + IPL thickness, could be a sign of ganglion cell damage induced by the treatment or could occur during the natural course of the disease.

Agreement of a Novel Artificial Intelligence Software With Optical Coherence Tomography and Manual Grading of the Optic Disc in Glaucoma.

The offline artificial intelligence (AI) on a smartphone-based fundus camera shows good agreement and correlation with the vertical cup-to-disc ratio (vCDR) from the spectral-domain optical coherence tomography (SD-OCT) and manual grading by experts. The purpose of this study is to assess the agreement of vCDR measured by a new AI software from optic disc images obtained using a validated smartphone-based imaging device, with SD-OCT vCDR measurements, and manual grading by experts on a stereoscopic fundus camera. In a prospective, cross-sectional study, participants above 18 years (Glaucoma and normal) underwent a dilated fundus evaluation, followed by optic disc imaging including a 42-degree monoscopic disc-centered image (Remidio NM-FOP-10), a 30-degree stereoscopic disc-centered image (Kowa nonmyd WX-3D desktop fundus camera), and disc analysis (Cirrus SD-OCT). Remidio FOP images were analyzed for vCDR using the new AI software, and Kowa stereoscopic images were manually graded by 3 fellowship-trained glaucoma specialists. We included 473 eyes of 244 participants. The vCDR values from the new AI software showed strong agreement with SD-OCT measurements [95% limits of agreement (LoA)=-0.13 to 0.16]. The agreement with SD-OCT was marginally better in eyes with higher vCDR (95% LoA=-0.15 to 0.12 for vCDR>0.8). Interclass correlation coefficient was 0.90 (95% CI, 0.88-0.91). The vCDR values from AI software showed a good correlation with the manual segmentation by experts (interclass correlation coefficient=0.89, 95% CI, 0.87-0.91) on stereoscopic images (95% LoA=-0.18 to 0.11) with agreement better for eyes with vCDR>0.8 (LoA=-0.12 to 0.08). The new AI software vCDR measurements had an excellent agreement and correlation with the SD-OCT and manual grading. The ability of the Medios AI to work offline, without requiring cloud-based inferencing, is an added advantage.

Deep Learning for Glaucoma Detection and Identification of Novel Diagnostic Areas in Diverse Real-World Datasets.

PurposeTo develop a three-dimensional (3D) deep learning algorithm to detect glaucoma using spectral-domain optical coherence tomography (SD-OCT) optic nerve head (ONH) cube scans and validate its performance on ethnically diverse real-world datasets and on cropped ONH scans.MethodsIn total, 2461 Cirrus SD-OCT ONH scans of 1012 eyes were obtained from the Glaucoma Clinic Imaging Database at the Byers Eye Institute, Stanford University, from March 2010 to December 2017. A 3D deep neural network was trained and tested on this unique raw OCT cube dataset to identify a multimodal definition of glaucoma excluding other concomitant retinal disease and optic neuropathies. A total of 1022 scans of 363 glaucomatous eyes (207 patients) and 542 scans of 291 normal eyes (167 patients) from Stanford were included in training, and 142 scans of 48 glaucomatous eyes (27 patients) and 61 scans of 39 normal eyes (23 patients) were included in the validation set. A total of 3371 scans (Cirrus SD-OCT) from four different countries were used for evaluation of the model: the non overlapping test dataset from Stanford (USA) consisted of 694 scans: 241 scans from 113 normal eyes of 66 patients and 453 scans of 157 glaucomatous eyes of 89 patients. The datasets from Hong Kong (total of 1625 scans; 666 OCT scans from 196 normal eyes of 99 patients and 959 scans of 277 glaucomatous eyes of 155 patients), India (total of 672 scans; 211 scans from 147 normal eyes of 98 patients and 461 scans from 171 glaucomatous eyes of 101 patients), and Nepal (total of 380 scans; 158 scans from 143 normal eyes of 89 patients and 222 scans from 174 glaucomatous eyes of 109 patients) were used for external evaluation. The performance of the model was then evaluated on manually cropped scans from Stanford using a new algorithm called DiagFind. The ONH region was cropped by identifying the appropriate zone of the image in the expected location relative to Bruch's Membrane Opening (BMO) using a commercially available imaging software. Subgroup analyses were performed in groups stratified by eyes, myopia severity of glaucoma, and on a set of glaucoma cases without field defects. Saliency maps were generated to highlight the areas the model used to make a prediction. The model's performance was compared to that of a glaucoma specialist using all available information on a subset of cases.ResultsThe 3D deep learning system achieved area under the curve (AUC) values of 0.91 (95% CI, 0.90–0.92), 0.80 (95% CI, 0.78–0.82), 0.94 (95% CI, 0.93–0.96), and 0.87 (95% CI, 0.85–0.90) on Stanford, Hong Kong, India, and Nepal datasets, respectively, to detect perimetric glaucoma and AUC values of 0.99 (95% CI, 0.97–1.00), 0.96 (95% CI, 0.93–1.00), and 0.92 (95% CI, 0.89–0.95) on severe, moderate, and mild myopia cases, respectively, and an AUC of 0.77 on cropped scans. The model achieved an AUC value of 0.92 (95% CI, 0.90–0.93) versus that of the human grader with an AUC value of 0.91 on the same subset of scans (). The performance of the model in terms of recall on glaucoma cases without field defects was found to be 0.76 (0.68–0.85). Saliency maps highlighted the lamina cribrosa in glaucomatous eyes versus superficial retina in normal eyes as the regions associated with classification.ConclusionsA 3D convolutional neural network (CNN) trained on SD-OCT ONH cubes can distinguish glaucoma from normal cases in diverse datasets obtained from four different countries. The model trained on additional random cropping data augmentation performed reasonably on manually cropped scans, indicating the importance of lamina cribrosa in glaucoma detection.Translational RelevanceA 3D CNN trained on SD-OCT ONH cubes was developed to detect glaucoma in diverse datasets obtained from four different countries and on cropped scans. The model identified lamina cribrosa as the region associated with glaucoma detection.

Multivariate Normative Comparison, a Novel Method for Improved Use of Retinal Nerve Fiber Layer Thickness to Detect Early Glaucoma

Detection of early glaucoma remains limited with the conventional analysis of the retinal nerve fiber layer (RNFL). This study assessed whether compensating the RNFL thickness for multiple demographic and anatomic factors improves the detection of glaucoma. Cross-sectional study. Three hundred eighty-seven patients with glaucoma and 2699 healthy participants. Two thousand six hundred ninety-nine healthy participants were enrolled to construct and test a multivariate compensation model, which then was applied in 387 healthy participants and 387 patients with glaucoma (early glaucoma, n= 219; moderate glaucoma, n= 97; and advanced glaucoma, n= 71). Participants underwent Cirrus spectral-domain OCT (Carl Zeiss Meditec) imaging of the optic disc and macular cubes. Compensated RNFL thickness was generated based on ethnicity, age, refractive error, optic disc (ratio, orientation, and area), fovea (distance and angle), and retinal vessel density. The RNFL thickness measurements and their corresponding areas under the receiver operating characteristic curve (AUCs) were obtained. Measured and compensated RNFL thickness measurements. After applying the Asian-specific compensation model, the standard deviation of RNFL thickness reduced, where the effect was greatest for Chinese participants (16.9%), followed by Malay participants (13.9%), and Indian participants (12.1%). Multivariate normative comparison outperformed measured RNFL for discrimination of early glaucoma (AUC, 0.90 vs. 0.85; P < 0.001), moderate glaucoma (AUC, 0.94 vs. 0.91; P < 0.001), and advanced glaucoma (AUC, 0.98 vs. 0.96; P < 0.001). The multivariate normative database of RNFL showed better glaucoma discrimination capability than conventional age-matched comparisons, suggesting that accounting for demographic and anatomic variance in RNFL thickness may have usefulness in improving glaucoma detection.

Age-related Changes of Macular Ganglion Cell-inner Plexiform Layer Thickness in Korean Elderly Subjects.

Purpose We sought to establish normative ranges of the ganglion cell-inner plexiform layer (GCIPL) thickness using spectral-domain optical coherence tomography in Korean elderly individuals and to identify factors that influence GCIPL thickness.Methods We conducted a retrospective, observational study of 114 healthy subjects (75 years old or older) who underwent comprehensive ophthalmic examinations at a single institution. GCIPL thickness was measured with the Cirrus spectral-domain optical coherence tomography system and automatic segmentation. Subjects were divided into two age groups: those younger than 80 years and those 80 years or older, respectively. A cross-sectional analysis was adopted to evaluate associations of GCIPL thickness with sex, age, intraocular pressure, optic disc rim area, axial length, spherical equivalent (SE) refractive errors, astigmatism, and body mass index.Results The average and minimum GCIPL thicknesses were 80.3 ± 5.6 µm and 76.3 ± 5.9 µm, respectively. The GCIPL thickness was significantly lower in the older group than in the younger group in the inferior, inferonasal, and inferotemporal segments (all p < 0.01). A thinner average GCIPL thickness was strongly associated with increasing age (β = -2.87, p = 0.021) and thinner circumpapillary retinal nerve fiber layer thickness (β = 2.87, p < 0.001) in all segments.ConclusionsGCIPL thickness decreased with age globally and in all segments, even after 75 years of age. Thinner GCIPL was associated with older age and thinner circumpapillary retinal nerve fiber layer. Age-related changes should be considered when using GCIPL thickness to assess glaucoma and other optic neuropathies characterized by retinal ganglion cell loss.

Diagnostic Ability of Individual Macular Layers by Spectral-Domain OCT in Different Stages of Glaucoma

To compare the diagnostic ability of macular intraretinal layer thickness with circumpapillary retinal nerve fiber layer (cpRNFL) thickness, either when used individually or in combination with cpRNFL for detecting early, moderate, and advanced glaucoma. Cross-sectional study. A total of 423 glaucoma participants and 423 age- and gender-matched normal participants. Participants underwent Cirrus spectral-domain OCT (SD-OCT) imaging (Carl Zeiss Meditec, Dublin, CA) using the optic disc and macular scanning protocols. Iowa Reference Algorithms (version 3.8.0) were used for intraretinal layer segmentation, and mean thickness of intraretinal layers was rescaled with magnification correction using axial length value. Thickness measurements of each layer/sector and their corresponding areas under the receiver operating characteristic curve (AUCs) were obtained. Glaucoma eyes were subdivided based on of their visual field severity (early, n= 234; moderate, n= 107; advanced, n= 82). Intraretinal layers. Some 67% of participants were male, their average ± standard deviation age was 65±9 years. Circumpapillary retinal nerve fiber layer, macular ganglion cell layer (mGCL), and macular inner plexiform layer (mIPL) were significantly thinner in the glaucoma groups (P < 0.0005). The 2 best parameters for detecting normal eyes from early glaucoma was cpRNFL (AUC= 0.861) and mGCL (AUC= 0.842), from moderate glaucoma was mGCL combined with inner plexiform layer (IPL) (AUC= 0.915) and cpRNFL (AUC= 0 .914), and from advanced glaucoma was mGCL-IPL (AUC= 0.984) and cpRNFL (AUC= 0.977). There was no statistical significance between AUCs for the macular parameter and cpRNFL thickness measurement at any of the severities (P > 0.05). Combining macular and cpRNFL parameters improved the diagnostic performance for early glaucoma (AUC= 0.908; P= 0.002) and moderate glaucoma (AUC= 0.944; P= 0.031) but not for advanced glaucoma (AUC= 0.991; P > 0.05). Single-layer mGCL thickness is comparable to the traditional cpRNFL thickness for the diagnosis of early/moderate glaucoma, whereas cpRNFL thickness remains the most efficient for advanced glaucoma. Combining macular measurements (GCL and GCL-IPL) and cpRNFL improved the discrimination of early/moderate glaucoma but not of advanced glaucoma. For the diagnosis of early glaucoma, both macular and optic disc scans should be used.

Evaluation of the association of macular ganglion cell-inner plexiform layer thickness and myopia in Chinese young adults.

To describe the distribution of ganglion cell-inner plexiform layer (GCIPL) thickness among Chinese young adults and report whether the decreased GCIPL thickness is associated with myopia. In this study, we included Chinese young adults who underwent Cirrus spectral domain-optical coherence tomography (SD-OCT). SD-OCT was used to measure average and minimum GCIPL thickness, and GCIPL thickness at all sectors. Subfoveal choroidal thickness (CT), axial length (AL), and spherical equivalents (SE) were also measured. A total of 348 eyes were included in the analysis. Average GCIPL thickness showed a significant difference between myopes and emmetropes, with 87.89 ± 3.65 μm for emmetropic groups and 82.65 ± 4.96 μm for myopic groups. The GCIPL thickness was significantly thinner in myopia than in emmetropia at all locations (P < 0.05), affirming that myopia was associated with thinner GCIPL thickness (P = 0.001). The mean subfoveal CT also showed a significant difference between myopes and emmetropes, with 330.57 ± 9.43 μm for emmetropic groups and 265.98 ± 4.12 μm for myopic groups. GCIPL (OR 0.863, 95% CI, 0.785-0.949), AL (OR 2.499, 95% CI, 1.532-4.075) and intraocular pressure (IOP) (OR 1.250, 95% CI, 1.086-1.438) revealed significant associations with myopia. When adjusting for AL, IOP, and anterior chamber depth (ACD) in the myopia subgroup, the GCIPL thickness remained positively associated. In a specific Chinese young population, myopic eyes have measurably less macular GCIPL thickness than normal eyes. Decreasing GCIPL thickness may be associated with the progression of myopia.

Use of Contact Lenses to Optimize OCT Scans of the Optic Nerve in Glaucoma Suspects or Patients with Glaucoma with High Myopia

Patients with myopia are at increased risk for the development of glaucoma. The inability to correct for axial length on spectral-domain (SD) OCT translates into lower signal strength and scan reliability in patients with high axial myopia. We evaluated the effectiveness of a contact lens to increase the signal strength and to assess optic nerve dimensions and nerve fiber layer (NFL) thickness using SD OCT in patients with glaucoma or who are glaucoma suspects with high axial myopia. Single-center, prospective, interventional study. Patients with axial lengths of more than 25.5 mm with a diagnosis of glaucoma or glaucoma suspect. The optic nerve cube 200×200 scan using the Cirrus SD OCT 400 (Carl Zeiss Meditec, Inc., Dublin, CA) was carried out first without the use of a contact lens and then repeated with placement of the contact lens to correct for the spherical equivalent of the refractive error. The primary outcome measure was the change in the average NFL thickness before and after use of the contact lens. Secondary outcome measures included the changes in cup volume, disc area, and rim area on OCT. Twelve patients were recruited (20 eyes); the average axial length was 27.06 mm, and the average signal strength interval increased by 1.73 (P= 0.001). With the use of a contact lens, the average NFL thickness was significantly thicker. None of the changes in the secondary outcome measures were significant: rim area, cup volume, or disc area. Based on our data, the use of a contact lens statistically improved the signal strength and average NFL thickness of the SD OCT scan. The ability to capture the perimeter of the optic disc accurately can be limited in the setting of peripapillary atrophy, which was present in all but 2 participants. Future studies with a larger number of participants and a wider range of axial myopia to discern if contact lens correction has a greater effect on the highest axial lengths are needed.

Abnormalities in the thickness of the retinal ganglion cell/inner plexiform layer in age-related macular degeneration

Introduction/Objective. The study aims to analyze the thickness of both the ganglion cell layer and the inner plexiform layer (GCL + IPL) among patients suffering from dry and wet form of age-related macular degeneration (AMD). Methods. One hundred ninety-five patients with AMD participated in the study, along with 94 healthy individuals (mean age 75.2 ? 7.8 years; range 55?86). They were divided into three groups: the first group, or group I, included 100 patients suffering from wet AMD; the second group, or group II, included 95 patients afflicted with dry AMD; the final 94 patients made up the control group, group III, of healthy individuals without systemic or ocular diseases. Measurements such as the average macular thickness, the average and minimum GCL + IPL thickness, and the GCL + IPL thickness in all six sectors were obtained by Cirrus spectral-domain optical coherence tomography (SD-OCT, Carl Zeiss Meditec, Inc., Dublin, CA, USA). SPSS version 20.0 was used to analyze the data, while the level of statistical significance was set at p &lt; 0.05. Results. In the case of patients with wet AMD, the average value for GCL + IPL thickness was 43.13 ?m, for patients with dry AMD the value was 66.73 ?m, and the average thickness measured for the control group was 86.23 ?m. There was a statistically significant difference between the average GCL + IPL and minimum GCL + IPL thicknesses between the groups (p &lt; 0.001). Lower values were noted for patients with wet AMD (p &lt; 0.001) than those with dry AMD. In the latter, the average GCL + IPL and the minimum GCL + IPL thicknesses were lower than those of the healthy participants, at a level of statistical significance (p &lt; 0.001). Conclusion. Participants with AMD exhibited thinner GCL + IPL than the healthy participants, as did the participants with wet AMD when compared to the participants with dry AMD.

Structure-function Relationship in Advanced Glaucoma After Reaching the RNFL Floor

To investigate the relationship between the central visual field (VF) and macular parameters obtained from spectral-domain optical coherence tomography (SD-OCT) in patients with advanced glaucoma that reached the cpRNFL thickness measurement floor and to determine whether the structural changes measured by SD-OCT are useful for estimating the functional status in these patients. A total of 68 eyes from 68 patients with advanced glaucoma were included. Only eyes having an average cpRNFL thickness of ≤57 μm that reached the measurement floor were included. Macular imaging using Cirrus SD-OCT and 10-2 Humphrey VF was performed. The VF mean deviation was converted to a linear scale using unlogged 1/Lambert values. The relationships between the central VF and various macular parameters were determined. Patients had a mean VF mean deviation of -20.69 dB and an average cpRNFL thickness of 51.76±3.61 μm. Correlations between the VF and all cpRNFL thickness parameters were not significant. However, significant correlations were found between the central VF and superonasal macular ganglion cell-inner plexiform layer thickness (r=0.334; P=0.003), inner nasal macular thickness (r=0.301; P=0.013), and outer nasal macular thickness (r=0.331; P=0.007). Even after the cpRNFL had reached the measurement floor, several macular parameters showed a statistically significant relationship with functional status in VF. In particular, the assessment of structural changes in the nasal macular region may be important in determining the central VF in advanced glaucoma.

Pediatric Normative Database of Retinal, Macular and Choroidal Values obtained with Spectral-Domain Optical Coherence Tomography

Purpose: To establish normative values in a Portuguese pediatric population for retinal nerve fiber layer (RNFL), macular, macular ganglion cell-inner plexiform layer (GCIPL) and subfoveal choroidal (SFC) thicknesses Methods: This cross-sectional study enrolled children, 4 to 17 years old, attending the Ophthalmology Department of Hospital de Braga. All subjects underwent comprehensive ophthalmologic examination and were scanned with Cirrus Spectral-Domain Optical Coherence Tomography (SD-OCT). Results: A total of 348 children (9.85±3.49 years) were included. Average RNFL thickness was 97.45±9.78µm and the distribution of RNFL thickness was in agreement with the ISNT rule. Average RNFL thickness showed a positive significant relationship with optic disc (OD) area (p=0.007). A significant positive relationship was also found for OD area (p=0.001 and p=0.04, respectively) and spherical equivalent (SE) (p=0.008 and p=0.004, respectively), in the inferior and nasal quadrants. Average macular thickness was 282.22±11.91µm. Central subfield was the thinnest region, followed by the external ring, while the internal ring was the thickest (p<0.001). Age, SE and gender were the strongest predictors of macular thickness. A negative association was found between the superior external macular thickness and age (p=0.009). A lower thickness in the outer macular region was associated with higher myopic refractive error (p<0.05). Boys had on average a thicker macula (p<0.05). Average GCIPL thickness was 84.97±4.78 µm and average SFC thickness was 374.76±42.51 µm. Conclusion: This study established a SD-OCT normative database for healthy Portuguese children aged 4 to 17 years old, which could improve diagnosis and management of pediatric ophthalmic disorders in children.

Diagnostic Performance of Macular Ganglion Cell/Inner Plexiform Layer Thickness to Discriminate Normal Eye from Eye with Early Glaucoma Using Cirrus Spectral-Domain Optical Coherence Tomography

&#x0D; &#x0D; &#x0D; Background: Glaucoma is a progressive optic neuropathy characterized by a progressive loss of retinal ganglion cells (RGC). In glaucomatous optic neuropathy, structural optic nerve changes may occur before detectable functional loss, which can be diagnosed early by detecting loss of RGC. This review was conducted to see the diagnostic performance of macular ganglion cell/inner plexiform layer (GC-IPL) thickness parameters to discriminate normal eye from early glaucoma eye using Cirrus Spectral-domain OCT compared to peri-papilarry Retinal Nerve Fiber Layer (RNFL) thickness parameters. &#x0D; Methods: Literature search was conducted from MEDLINE database using Pubmed, Clinical Key, and ScienceDirect. No publication date was set, and only articles published in English were included. Reference list from the included studies were also checked for potentially relevant articles. Results: Twenty articles were found related to search term. Seven articles met the inclusion criteria. Fourteen others were excluded. All studies revealed significant thinner GC-IPL and RNFL average thickness in glaucoma patients compared to normal patients. GC-IPL Average was inferior to GC-IPL Minimum and RNFL inferior in determining normal eye from early glaucomatous eyes. Studies evaluating the diagnostic performance of Ganglion Cells Complex (GCC) thickness also found low sensitivity values, ranging between 61.0% and 78.6% for average GCC. &#x0D; Conclusion: Diagnostic performance of GC-IPL is comparable to RNFL parameters measurement in detecting early glaucoma eyes. Best performance in detecting early glaucoma were showed by GC-IPL minimum and RNFL inferior. &#x0D; &#x0D; &#x0D;

Effects of Measurement Center Shift on Ganglion Cell-inner Plexiform Layer Thickness Measurements.

Our authors studied the effects of measurement center shift on ganglion cell-inner plexiform layer (GCIPL) thickness measurements in Cirrus spectral-domain optical coherence tomography (SD-OCT). The measurement center shift affects the GCIPL thickness measurement depending on the distance of shift. The purpose of this study was to explore changes in macular GCIPL thicknesses measurements after manual shifting of the measurement center using SD-OCT. A prospective study was conducted. A total of 30 normal eyes of 30 subjects were included in the study. An experienced examiner obtained two consecutive measurements of GCIPL thickness using SD-OCT. Coefficients of repeatability were calculated for the average, minimum, and sectoral (superotemporal, superior, superonasal, inferonasal, inferior, and inferotemporal) thicknesses. Next, the measurement center was manually shifted from the foveal center. Three measurement centers were horizontally placed at 59-μm intervals from the foveal center, and two further centers were placed 176 μm apart. Also, three measurement centers were vertically placed at 47-μm intervals from the foveal center, and two further centers were placed 142 μm apart. The thickness of GCIPL was measured again at each shift point, and the changes of thickness before and after movement were analyzed. When the measurement centers were shifted to positions 59 μm horizontally or 47 μm vertically from the fovea, no significant changes in GCIPL thicknesses were evident. However, upon more pronounced shifting, the average GCIPL thickness of the direction of the shift region was significantly lower than baseline, whereas the GCIPL of the diametrically opposite sector was thicker than baseline. The impact of changes associated with shifting of the measurement center should be taken into consideration when measuring GCIPL thickness in patients with retinal diseases, glaucoma, or neuro-ophthalmological conditions.

Structural changes of macula and optic disk of the fellow eye in patients with nonarteritic anterior ischemic optic neuropathy.

The aim was to assess the ganglion cell complex (GCC) thickness, retinal nerve fiber layer (RNFL) thickness and optic disk features in the affected eyes (AE) and unaffected fellow eyes (FE) of subjects with unilateral nonarteritic anterior ischemic optic neuropathy (NAION) and to compare with healthy control eyes (CE) using spectral domain-optical coherence tomography (SD-OCT). This study included 28 patients and age, sex and refraction-matched 28 control subjects. Mean GCC thickness and peripapillary RNFL thickness in four quadrants measured by cirrus SD-OCT were evaluated in both AE and FE of patients and CE. In addition, optic disk measurements obtained with OCT were evaluated. Mean GCC thickness was significantly lower in AE compared with both FE and CE (P < 0.001), and mean GCC thickness in FE was significantly lower than CE (P = 0.022). In addition, mean RNFL thickness in superior and nasal quadrants significantly decreased in FE compared with CE (P = 0.020 and 0.010, respectively). Furthermore, AE had significantly greater optic disk cupping compared with both FE and CE (P < 0.001). GCC and RNFL thickness decreased significantly at late stages of NAION, in both AE and FE compared with CE, suggesting that some subclinical structural changes may occur in FE despite lack of obvious visual symptoms. In addition, there was no significant difference in optic disk features between the CE and FE. And significantly greater optic disk cupping in the AE compared with both FE and CE supports the acquired enlargement of cupping after the onset of NAION.

Diagnostic value of ganglion cell-inner plexiform layer for early detection of ethambutol-induced optic neuropathy

AimTo evaluate the diagnostic value of macular ganglion cell-inner plexiform layer (mGCIPL) thickness versus peripapillary retinal nerve fibre layer (pRNFL) thickness for the early detection of ethambutol-induced optic neuropathy (EON).MethodsTwenty-eight...

Influence of Disc Size on the Diagnostic Accuracy of Cirrus Spectral-Domain Optical Coherence Tomography in Glaucoma.

Purpose To examine the influence of optic disc size on the diagnostic accuracy of optic nerve head (ONH) parameters determined by Cirrus spectral-domain optical coherence tomography (Cirrus HD-OCT). Methods A total of 51 eyes of 51 normal participants and 71 eyes of 71 glaucoma patients were examined. ONH imaging was obtained by Cirrus HD-OCT. Sensitivity at a fixed 90% specificity along with the area under the receiver operating characteristic curve (AUC) for continuous parameters were analyzed. We also examined the coefficients of variation (CoV) for sensitivity estimates, as these have been used to test and quantify the influence of optic disc size on diagnostic accuracy. The influence of optic disc size on the glaucoma diagnosis was assessed by the likelihood ratio chi-square test. Results Among the continuous parameters, the best diagnostic accuracy was seen for the average rim area, which had an AUC of 0.96. The most reliable factor across the disc size groups was the rim area (CoV, 2.8%). The diagnostic accuracy of the rim area did not appear to be influenced by optic disc size (P = 0.17). Conclusions The high diagnostic accuracy of the rim area demonstrated by Cirrus HD-OCT for the quantitative assessment of the ONH was not significantly affected by disc size in this study.

Evaluation of changes in retinal fiber layer thickness in pseudoexfoliation syndrome using spectral domain optical coherence tomography

Background: Pseudoexfoliation syndrome (PEX) is a disorder characterized by the progressive accumulation of fibrillary extracellular deposits in several ocular tissues including the iris, anterior chamber angle, lens capsule, and zonules. It is an independent risk factor for glaucomatous optic nerve damage. Retinal nerve fiber layer thickness analysis using optical coherence tomography (RNFL-OCT) is a documented investigative tool to detect preperimetric glaucoma and helps to detect glaucoma early. Objective: The objective of this study was to evaluate the retinal nerve fiber thickness in eyes with PEX using OCT and to compare them with healthy controls. Materials and Methods: This prospective cross-sectional control study was conducted at GMC, Srinagar, in which retinal nerve fiber thickness 50 patients of PEX and 50 healthy control subjects were compared using Cirrus spectral domain OCT (Carl Zeiss). Complete ocular and physical examination was also done in all subjects. Results: Mean age of Group A (PEX group) was 59.06 ± 6.5 years and of Group B (control) was 57.04 ± 7.1 years (P = 0.51). Both groups were gender matched with male preponderance (P = 0.41). Mean average peripapillary RNFL thickness was 76.13 μm ± 13.65 in Group A (PEX group) and 82.61 ± 12.78 μm in Group B (control group) (P = 0.10). Mean superior RNFL thickness was 94.17 ± 16.25 in PEX group and 100.23 μm ± 13.21 in control group (P = 0.09). Mean inferior RNFL thickness was 89.67 μm ± 18.25 in PEX group and 102.45 μm ± 12.50 in control group (P = 0.03). Mean nasal RNFL thickness was 62.36 μm ± 15.36 in PEX group and 64.66 μm ± 13.71 (P = 0.56) in control group. Mean temporal RNFL thickness was 58.34 μm ± 14.32 in PEX group and 63.11 μm ± 15.25 (P = 0.08) in control group. Mean RNFL thickness was seen decreased in all PEX patients in all quadrants; however, statistically significant differences were detected only in inferior quadrant groups. Conclusion: RNFL thickness is decreased in PEX patients. SD-OCT is a very reliable investigative tool to measure RNFL thickness, which helps in detecting preperimetric glaucoma.