Domain Optical Coherence Tomography Research Articles

Diagnosis of multiple sclerosis using optical coherence tomography supported by artificial intelligence.

Current procedures for diagnosing multiple sclerosis (MS) present a series of limitations, making it critically important to identify new biomarkers. The aim of the study was to identify new biomarkers for the early diagnosis of MS using spectral-domain optical coherence tomography (OCT) and artificial intelligence. Spectral domain OCT was performed on 79 patients with relapsing-remitting multiple sclerosis (RRMS) (disease duration ≤ 2 years, no history of optic neuritis) and on 69 age-matched healthy controls using the posterior pole protocol that incorporates the anatomic Positioning System. Median retinal thickness values in both eyes and inter-eye difference in healthy controls and patients were evaluated by area under the receiver operating characteristic (AUROC) curve analysis in the foveal, parafoveal and perifoveal areas and in the overall area spanned by the three rings. The structures with the greatest discriminant capacity - retinal thickness and inter-eye difference - were used as inputs to a convolutional neural network to assess the diagnostic capability. Analysis of retinal thickness and inter-eye difference in RRMS patients revealed that greatest alteration occurred in the ganglion cell (GCL), inner plexiform (IPL), and inner retinal (IRL) layers. By using the average thickness of the GCL (AUROC=0.82) and the inter-eye difference in the IPL (AUROC=0.71) as inputs to a two-layer convolutional neural network, automatic diagnosis attained accuracy=0.87, sensitivity=0.82, and specificity=0.92. This study adds weight to the argument that neuroretinal structure analysis could be incorporated into the diagnostic criteria for MS.

Label-free intratissue activity imaging of alveolar organoids with dynamic optical coherence tomography.

An organoid is a three-dimensional (3D) in vitro cell culture emulating human organs. We applied 3D dynamic optical coherence tomography (DOCT) to visualize the intratissue and intracellular activities of human induced pluripotent stem cells (hiPSCs)-derived alveolar organoids in normal and fibrosis models. 3D DOCT data were acquired with an 840-nm spectral domain optical coherence tomography with axial and lateral resolutions of 3.8 µm (in tissue) and 4.9 µm, respectively. The DOCT images were obtained by the logarithmic-intensity-variance (LIV) algorithm, which is sensitive to the signal fluctuation magnitude. The LIV images revealed cystic structures surrounded by high-LIV borders and mesh-like structures with low LIV. The former may be alveoli with a highly dynamics epithelium, while the latter may be fibroblasts. The LIV images also demonstrated the abnormal repair of the alveolar epithelium.

Evaluation of Macular Ganglion Cell-Inner Plexiform Layer in Children with Deprivational Amblyopia Who Underwent Unilateral Cataract Surgery.

Background and Objectives: The aim of the study is to assess macular ganglion cell and inner plexiform layer (mGCIPL) thickness in deprivational amblyopic eyes (AE), fellow non-amblyopic eyes (FE) and normal eyes (NE) using spectral. domain optical coherence tomography (SD-OCT). Materials and Methods: Twenty two children (64% boys) who underwent surgical removal of unilateral congenital or developmental cataracts and exhibited visual impairment despite postoperative visual rehabilitation were included in the study. Cataract surgery was performed in patients aged 55.82 ± 35.85 months (range 6 to 114 months). The mean age of the study group was 9.73 ± 2.85 years (range 5 to 15 years). The comparison group consisted of 22 healthy age- and gender-matched children. The best corrected visual acuity (BCVA) after surgery was: 0.75 ± 0.27 (range 0.3 to 1.3) in AE, 0.1 ± 0.13 (range 0 to 0.5) in FE and 0.04 ± 0.07 (range 0 to 0.2) in NE. OCT scans were performed in all patients and subsequently corrected for axial length related magnification errors. Results: The average thickness of mGCIPL was 70.6 ± 11.28 μm in AE; 77.50 ± 6.72 μm in FE and 81.73 ± 5.18 μm in NE. We found that mGCIPL was statistically significantly thinner in deprivation AE compared to FE (p = 0.038) and NE (p = 0.0005). The minimum thickness of mGCIPL was respectively: 62.68 ± 13.2 μm, 70.3 ± 7.61 μm, and 74.5 ± 5.47, and also differed between AE and FE (p = 0.023) and AE and NE (p = 0.0004). Also, measurements in the inferior, inferotemporal, and superotemporal sectors showed thinning of mGCIPL in AE compared to NE. Conclusions: This analysis may suggest that deprivational amblyopia caused by unilateral congenital or developmental cataract in children may be associated with mGCIPL thinning.

MORPHOLOGICAL ASSESSMENT OF DIABETIC RETINOPATHY

A morphological study of the thickness of the choroid in patients with diabetes using spectral- domain optical coherence tomography was carried out in order to analyze the morphological changes of choroidal vessels and their role in the mechanism of diabetic retinopathy, which was carried out on the eyes of 203 participants with diabetes and on the eyes of 48 we are healthy people. The thickness of the choroid in the area of the foveal lesion was measured using optical coherence tomography with enhanced imaging. Participants were grouped according to the degree of diabetic retinopathy: no diabetic changes, mild or moderate, or severe nonproliferative or proliferative diabetic retinopathy. Study parameters included history, age, axial length, intraocular pressure, central retinal thickness, fasting glucose, and blood pressure. As a result, subfoveal choroidal thickness was smaller in eyes with nonproliferative or proliferative diabetic retinopathy than in normal eyes (p <0.01). However, there was no diff erence between eyes with nonproliferative and proliferative diabetic retinopathy or between eyes without diabetic changes and controls. Eyes with macular edema did not show a signifi cant diff erence in choroidal thickness compared to eyes with normal macular contours. Consequently, the central choroid thins when eyes exhibit diabetic retinal changes. However, the presence of diabetic macular edema or proliferative changes was not associated with more pronounced choroidal thinning.

Changes in retinal layers in type 1 diabetes mellitus without retinopathy measured by spectral domain and swept source OCTs

To evaluate changes in inner retinal layer (IRL) thicknesses in patients with type 1 diabetes mellitus (DM1) with no diabetic retinopathy (DR) using two different optical coherence tomography (OCT) devices. Ninety DM1 and 60 healthy eyes were evaluated using spectral domain (SD)-OCT and swept source (SS)-OCT to measure changes in the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL) and inner nuclear layer (INL) thicknesses in all Early Treatment of Diabetic Retinopathy Study (ETDRS) macular areas. Functional tests were performed in both groups, including ETDRS with 100, 2.5 and 1.25% contrast, and color vision. The mean ages were 42.93 ± 13.62 and 41.52 ± 13.05 years in the diabetic and control groups, respectively. Visual acuity (VA) with ETDRS 1.25% was lower in the DM1 patients. Both ETDRS 2.5% and color vision were lower in the DM1 group but did not reach statistical significance. Retinal thicknesses in the central area and in the vertical outer areas were higher in the DM1 group. Differences were found in the IRL with no changes in the outer ones. Long-term DM1 patients with no DR maintained visual function, with a decrease in VA with 1.25% ETDRS contrast. Macular thickness measurements were higher using Spectralis SD-OCT than DRI Triton SS-OCT, and DM1 patients had a decrease in IRL thickness, especially in the GCL at the parafoveal level, generating thinning of the RNFL in the peripheral areas. There were no differences in outer retinal layer (ORL) thickness.

Comparative Study of Iris and Retinal Images for Early Detection of Diabetic Mellitus

The recent increase in the number of diabetic cases due to genetic reasons or sedentary lifestyle, necessitates urgent need for an effective glucose monitoring system. Certainly, periodic glucose level monitoring in the blood will prevent from entering chronic diabetic condition and a noninvasive monitoring tool leads to a simple and automated diagnosis procedure. In this present work, an iridology-based diagnosis of diabetes has been discussed and is compared with a standard retinal imaging modality. Two subject groups, one group of 30 subjects without diabetes, the other group with 20 subjects of controlled diabetes with less than two years duration and 25 subjects with more than two years of uncontrolled diabetes were evaluated. Iris images are acquired using an iriscope and subsequently compared it with that of retinal spectral domain optical coherence tomography (SDOCT) images of the same subjects. The segmentation of the pancreas region in the iris images and the retinal layers in the SDOCT retinal images are performed automatically to predict Diabetic Mellitus (DM). The selected features of the segmented region are given as input to k-Nearest Neighbor, Support Vector Machine and Random Forest classifiers for discriminating diabetic and non-diabetic normal cases. The results showed that iris images are able to reveal the diabetic condition of the subjects even before their retina could reveal the same. However, elaborate extensive studies have to be carried out in order to validate iridology as a best noninvasive tool for detection of diabetes at the early stage itself.

Structure versus function in high myopia using optical coherence tomography and automated perimetry

BackgroundTo examine the structure–function relationship between retinal thickness using spectral‐domain optical coherence tomography and standard automated perimetry in high myopia.MethodsThe study population comprised 58 highly myopic individuals with no posterior abnormalities (mean spherical equivalent refraction ≤ −6.00 D and axial length ≥ 26.0-mm). All eyes underwent optical coherence tomography with the Spectralis spectral domain optical coherence tomograph and visual field evaluation with the Humphrey Field Analyzer II‐i. Average macular layer thicknesses in each quadrant were calculated in a 6 × 6-mm area centred on the fovea. The visual field was assessed from 17 central locations (10°), approximately the equivalent of the area tested by optical coherence tomography in the macular scan. Linear correlations were made between different macular layer thicknesses and peripapillary retinal nerve layer thickness with their matched visual field sensitivities.ResultsParticipant ages were 28.2 ± 6.4-years, mean spherical equivalent refractions were −8.20 ± 1.40-D and axial lengths were 26.7 ± 0.7-mm. There were significant positive correlations between layer thickness and corresponding visual field sensitivities as follows: ganglion cell layer in all quadrants, temporal quadrant of the nerve fibre layer with nasal quadrant of the visual field, inferior quadrant of the outer nuclear layer with superior visual field, and temporal‐superior peripapillary nerve fibre layer with nasal‐inferior visual field.ConclusionThe correlation between retinal layer thicknesses and visual field sensitivity could be explained by myopia‐related losses due to lateral retinal stretching, with further research required to investigate this.

A Study of Retinal Nerve Fiber Layer Thickness by using Spectral Domain Optical Coherence Tomography in Older Adults with Diabetes Mellitus

Introduction: Peripapillary retinal nerve fiber layer (RNFL) thinning occurs in the diabetic patients earlier than the detectable diabetic retinopathy. We conducted this study to evaluate the RNFL thickness and macular thickness in elderly diabetic patients using optical coherence tomography in comparison to healthy controls. Material and methods: One fifty study participants were divided in 3 groups (50 each): normal subjects, patients with diabetes with no detectable diabetic retinopathy (NDR) and patients with diabetic retinopathy (DR) of differing severity. The RNFL thickness and macular thickness was measured using spectral-domain optical coherence tomography (SD OCT). Results: The RNFL thickness around the optic disc differed significantly among all the 3 groups and tended to become thinner as the patient develops DR in elderly subjects. The mean, superior-temporal and upper nasal peripapillary RNFL thickness differed among all the 3 groups. We observed that, mean superior, temporal, inferior and nasal RNFL tended to be thinner as the patient develops DR. Conclusion: The RNFL thickness, macular thickness and ganglion cell complex thinning differed significantly between the healthy group and diabetic group without clinical DR. The RNFL thinning (measured by Spectral-domain OCT) is an early neurodegenerative ocular change in diabetic patients even before onset of diabetic retinopathy.

Dexamethasone for unresponsive diabetic macular oedema: optical coherence tomography biomarkers.

To analyse the effects of intravitreal dexamethasone implant (DEX) in patients with diabetic macular oedema (DME) unresponsive to ranibizumab treatment, in relation to the inflammatory optical coherence tomography (OCT) retinal features, subfoveal neuroretinal detachment (SND) and hyperreflective retinal spots (HRS). Patients with DME poorly responsive to three injections of ranibizumab were treated with DEX. Best-corrected visual acuity (BCVA) and central macula thickness (CMT, measured by Spectralis SD-OCT) were assessed at baseline and at 1, 3, and 6months. Overall, 44 eyes were included in the study. In the whole group, mean BCVA (baseline 51.5±8.3 letters) increased significantly at 1month (to 56.9±8.8 letters; Tukey HSD p=0.017) and was 55.5±8.8 letters at 3months (Tukey HSD p=0.128). Central macula thickness (CMT) reduced significantly at 1 and 3months (417±149μm and 469±128μm, respectively, both Tukey HSD p<0.001 versus baseline). Subgroup analysis showed a significant BCVA increase at 1month in eyes with SND+HRS (from 51.2±9.2 to 58.2±9.0, p=0.029), and a trend to BCVA increase in eyes with HRS (from 52.3±6.4 to 56.8±7.9, p=0.080), with a significant CMT decrease in both groups (p<0.001). No changes of either parameter were found in eyes without SND and HRS. Spectral domain OCT is useful in identifying some inflammatory features in DME. Among DME eyes 'poorly responsive' to ranibizumab, those with SND and HRS responded better to DEX implants than those without these features.

Comparing imaging capabilities of spectral domain and swept source optical coherence tomography angiography in healthy subjects and central serous retinopathy

BackgroundThere are two forms of system implementation of optical coherence tomography angiography (OCTA) in ophthalmic imaging, i.e., spectral domain (SD-) and swept source OCTA (SS-OCTA). The purpose of this paper is to compare the SD-OCTA and SS-OCTA for elucidating structural and vascular features associated with central serous retinopathy (CSR), and to evaluate the effects of CSR on SD- and SS-OCTA’s imaging capabilities.MethodsNormal subjects and CSR patients were imaged by SD- and SS-OCTA using 3 × 3 mm and 6 × 6 mm scan patterns. OCT signal strengths at the superficial retina, deep retina, Sattler’s layer and Haller’s layer were used to compare the ability of SD- and SS-OCTA to image structural features. In addition, the ability to acquire angiograms were discussed by evaluating retinal vessel density. Central serous volume (CSV) was measured and it was correlated with difference in signal strengths (∆S) between two OCTA devices.ResultsSeven normal eyes and seven diseased eyes were recruited. Results showed no significant differences between SD- and SS-OCT in detecting structural features of the retinal layer according to the paired t-test. However, when imaging the Sattler’s layer for normal eyes, a significant difference is found between SD- and SS-OCT (p < 0.0001 for 3 × 3 mm scan, and p = 0.0002 for 6 × 6 mm); while for CSR eyes, the corresponding values were p < 0.0001 and p = 0.0003, respectively. At Haller’s layer for normal eyes, the corresponding values were p = 0.0004 and p = 0.0014; and for CSR eyes, p = 0.0004 and p < 0.0001, respectively. A strong correlation between ∆S and CSV was observed in the Sattler’s layer (3 × 3 mm – p = 0.0031 and R2 = 0.951; 6 × 6 mm – p = 0.0075 and R2 = 0.911) and Haller’s layer (3 × 3 mm – p = 0.0026 and R2 = 0.955; 6 × 6 mm – p = 0.0013 and R2 = 0.972).ConclusionsThe results suggest no differences between SD- and SS-OCTA for imaging the retinal layers however, when imaging beyond retinal layers, SS-OCTA appears advantageous in detecting returning signals. In CSR cases, the CSV may have an impact on sub-CSR tissue imaging and appears to have more impact on SD- than SS-OCTA.

Comparison of cross sectional optical coherence tomography images of elevated optic nerve heads across acquisition devices and scan protocols

BackgroundOptic nerve head measurements extracted from optical coherence tomography (OCT) show promise for monitoring clinical conditions with elevated optic nerve heads. The aim of this study is to compare reliability within and between raters and between image acquisition devices of optic nerve measurements derived from OCT scans in eyes with varying degrees of optic nerve elevation.MethodsWide angle line scans and narrow angle radial scans through optic nerve heads were obtained using three spectral domain(SD) OCT devices on 5 subjects (6 swollen optic nerves, 4 normal optic nerves). Three raters independently semi-manually segmented the internal limiting membrane(ILM) and Bruch’s membrane(BM) on each scan using customized software. One rater segmented each scan twice. Segmentations were qualitatively and quantitatively compared. Inter-rater, intra-rater and inter-device reliability was assessed for the optic nerve cross sectional area calculated from the ILM and BM segmentations using intraclass correlation coefficients and graphical comparison.ResultsLine scans from all devices were qualitatively similar. Radial scans for which frame rate could not be adjusted were of lower quality. Intra-rater reliability for segmentation and optic nerve cross sectional area was better than inter-rater reliability, which was better than inter-device reliability, though all ICC exceeded 0.95. Reliability was not impacted by the degree of optic nerve elevation.ConclusionsSD-OCT devices acquired similar quality scans of the optic nerve head, with choice of scan protocol affecting the quality. For image derived markers, variability between devices was greater than that attributable to inter and intra-rater differences.

Intraretinal Correlates of Reticular Pseudodrusen Revealed by Autofluorescence and En Face OCT.

PurposeWe sought to determine whether information revealed from the reflectance, autofluorescence, and absorption properties of RPE cells situated posterior to reticular pseudodrusen (RPD) could provide insight into the origins and structure of RPD.MethodsRPD were studied qualitatively by near-infrared fundus autofluorescence (NIR-AF), short-wavelength fundus autofluorescence (SW-AF), and infrared reflectance (IR-R) images, and the presentation was compared to horizontal and en face spectral domain optical coherence tomographic (SD-OCT) images. Images were acquired from 23 patients (39 eyes) diagnosed with RPD (mean age 80.7 ± 7.1 [SD]; 16 female; 4 Hispanics, 19 non-Hispanic whites).ResultsIn SW-AF, NIR-AF, and IR-R images, fundus RPD were recognized as interlacing networks of small scale variations in IR-R and fluorescence (SW-AF, NIR-AF) intensities. Darkened foci of RPD colocalized in SW-AF and NIR-AF images, and in SD-OCT images corresponded to disturbances of the interdigitation (IZ) and ellipsoid (EZ) zones and to more pronounced hyperreflective lesions traversing photoreceptor-attributable bands in SD-OCT images. Qualitative assessment of the outer nuclear layer (ONL) revealed thinning as RPD extended radially from the outer to inner retina. In en face OCT, hyperreflective areas in the EZ band correlated topographically with hyporeflective foci at the level of the RPE.ConclusionsThe hyperreflective lesions corresponding to RPD in SD-OCT scans are likely indicative of degenerating photoreceptor cells. The darkened foci at positions of RPD in NIR-AF and en face OCT images indicate changes in the RPE monolayer with the reduced NIR-AF and en face OCT signal suggesting a reduction in melanin that could be accounted for by RPE thinning.

Inter-visit Test-Retest Variability of OCT in Glaucoma.

To determine the inter-visit test-retest variability (TRV) of a spectral domain optical coherence tomograph, the Topcon 3D OCT-2000, in the measurement of optic nerve head topography, peripapillary retinal nerve fiber layer (pRNFL), and macular ganglion cell complex (GCC) parameters in glaucoma patients. We also examine whether TRV with this instrument varies with the extent of glaucomatous damage. Twenty-four subjects with varying degrees of glaucoma severity provided 41 eyes with usable results for the study. 3D Disc Retinal Nerve Fiber Layer Analysis and Macula V (GCC) scans were repeated 1 week apart, at the same time of day, to determine the inter-visit TRV. TRV was determined using Bland-Altman limits of agreement (LoA) and the resulting coefficients of repeatability (CR). The overall horizontal and vertical cup/disc ratio CRs were 0.05 and 0.07, respectively. The GCC CR was 2.9 μm. In contrast, average pRNFL TRV expanded with increasing damage, with the LoA being well fitted by ±(34.67 - 0.294(d)), where d is the pRNFL thickness. A more complex model, with constant LoA of ±5.61 μm at d >82 μm, and linearly expanding TRV below that, achieved marginal significance (P < .06). The repeatability of GCC measurements with this instrument was excellent. The determination of statistically significant change in average pRNFL should take into account average pRNFL thickness.

Effect of medicinal treatment on epithelial wound healing after phacoemulsification

to compare the dynamics of epithelial wound healing under two different post-op treatments in patients after uncomplicated phacoemulsification. This prospective randomized clinical trial included 40 eyes of 40 patients aged 66.4±8.2 years who underwent uncomplicated phacoemulsification with flexible intraocular lens implantation through a 2.2-mm corneal incision. Patients were randomized to receive either dexamethasone 0.1% and diclofenac 0.1% (n=20 eyes, Group I), or bromfenac 0.09% (n=20 eyes, Group II). Also, all patients instilled levofloxacin 0.5%. The dynamics of epithelial wound healing was assessed with the RTVue-100 spectral domain optical coherence tomograph with CAM-L corneal module in the 3D CORNEA mode 2 hours after surgery and on days 1, 3, 5, and 10. The postoperative period was uneventful in all cases. Two hours after surgery, epithelial defects were found in all eyes and their length did not differ statistically p=0.47. On the first day after surgery, complete epithelization was observed in 30% of cases from Group I and 60% of cases from Group II. The average length of epithelial defects was reliably smaller in Group II than in Group I (p=0.04 respectively). On postoperative day 3, 20% eyes from Group I still had epithelial defects with the average length of 0.45±0.13 mm, while there was only one eye with a 0.2-mm epithelial defect in Group II. Finally, on postoperative day 5, there was a single 0.3-mm epithelial defect in one eye from Group I. On day 10, none of the patients had epithelial defects in either group. Epithelial wound healing at the site of corneal incision after non-complicated phacoemulsification was found to be faster in patients instilled with bromfenac twice daily than in patients receiving dexamethasone and diclofenac four times daily as anti-inflammatory therapy and given topical fluoroquinolones for antibacterial purpose.

One-Year Outcomes of the Treat-and-Extend Approach with Aflibercept in Age-Related Macular Degeneration: Effects on Typical Choroidal Neovascularization and Retinal Angiomatous Proliferation

Objective: To investigate functional/morphological outcomes of the treat-and-extend regimen (TER) with aflibercept in typical choroidal neovascularization (CNV) and retinal angiomatous proliferation (RAP) secondary to exudative age-related macular degeneration (AMD). Methods: This was a retrospective study of 37 eyes treated with 2 mg aflibercept according to a TER protocol. Examinations included best corrected visual acuity (BCVA), numbers of injections, and visits needed. Additionally, quantitative/qualitative analyses with fluorescein angiography and spectral- domain optical coherence tomography were conducted at baseline as well as at 3, 6, and 12 months. Results: BCVA significantly improved from 0.6 ± 0.27 to 0.4 ± 0.34 logMAR. The final mean numbers of injections were 8.03 ± 1.27 and 7.28 ± 0.75 and the numbers of visits 6.5 ± 1.09 and 7.14 ± 1.57 in typical CNV and in RAP or atypical CNV, respectively, and they did not differ between the different subtypes of CNV (p > 0.05). Conclusions: Aflibercept in TER is effective for all exudative AMD subtypes. The patient's visual gain, the mean number of injections, and the number of visits needed did not depend on the subtype of CNV.

Retinal structure in Down's syndrome; potential markers of Alzheimer's disease

SummaryThe purpose of this study is to investigate degeneration and apoptosis of retinal cells in people with Down's syndrome (DS) and the relationship with aging. People with DS have a high risk of developing early‐onset Alzheimer's disease (AD) with an increasing age‐related prevalence.Spectral‐domain optical coherence tomography (SD‐OCT) was used to investigate the structure of the retina in 51 people with DS between the ages of 18 and 56. Thickness and volume of the retinal layers has been compared to that of age‐and‐sex‐matched healthy control participants. SD‐OCT has not been used in a large DS study previously and our results show significant differences between the DS and control retinal structures. We found that people with DS had significantly thicker RNFL in all quadrants (p &lt; 0.001) apart from the nasal quadrant. DS group also had significantly greater retinal volume than the control group (p &lt; 0.001).This finding is unexpected as research from the AD population shows thinning retinal layers and decreased retinal volume. Conclusions will be discussed and relationships with age and cognitive function explored. Future work will investigate the rate of apoptosing cells in the retinas of DS.

Effect of vitreomacular adhesion and vitreous gel on age-related reduction of macular thickness: a retrospective observational study

ObjectiveTo investigate the effects of vitreomacular adhesion (VMA), vitreomacular separation (VMS) and absence of vitreous gel due to vitrectomy on macular thickness measured in the spectral domain optical coherence tomographic...

Optic Nerve Parameters in Obese Children as Measured by Spectral Domain Optical Coherence Tomography

ABSTRACTPurpose: To investigate whether an association exists between obesity and optic nerve parameters. Methods: This was a prospective comparative study including 125 eyes of 63 obese and 122 eyes of 62 healthy pediatric subjects. Optic nerve measurements were performed using the Cirrus spectral domain optical coherence tomograph (SD-OCT). Results: The disc area, cup volume, mean and vertical C/D ratio, inferior and temporal RNFL thickness values were significantly higher in the control group than the obese group; however, age, sex, mean, superior and nasal RNFL thickness and rim area measurements were not statistically significantly different between the two groups. Age was significantly negatively correlated with temporal RNFL thickness in the obese group. Girls had significantly higher rim area, mean and superior RNFL thickness, and lower cup volume and vertical C/D ratio than boys in the obese group. Conclusion: These results could be helpful in the diagnosis and follow-up of obese children.

Coronary Artery Disease and Reticular Macular Disease, a Subphenotype of Early Age-Related Macular Degeneration

ABSTRACTPurpose: Reticular macular disease (RMD) is the highest risk form of early age-related macular degeneration and also specifically confers decreased longevity. However, because RMD requires advanced retinal imaging for adequate detection of its characteristic subretinal drusenoid deposits (SDD), it has not yet been completely studied with respect to coronary artery disease (CAD), the leading cause of death in the developed world. Because CAD appears in middle age, our purpose was to screen patients aged 45–80 years, documented either with or without CAD, to determine if CAD is associated with RMD.Design: A prospective cohort study of patients with documented CAD status and no known retinal disease in a clinical practice setting at one institution.Subjects and Controls: A number of 76 eyes from 38 consecutive patients (23 with documented CAD, 15 controls documented without CAD; 47.4% female; mean age 66.7 years).Methods: Patients were imaged with near-infrared reflectance/spectral domain optical coherence tomography and assessed in masked fashion by two graders for the presence of SDD lesions of RMD and soft drusen.Main Outcome Measures: Presence or absence of RMD/SDD and soft drusen.Results: RMD was more frequent in patients with CAD versus those without (Relative Risk [RR] = 2.1, CI = 1.08–3.95, P = 0.03). There was no association of CAD with soft drusen.Conclusions: A specific relationship between CAD and RMD suggests common systemic causes for both and warrants further study.

Repeatability of central and peripheral corneal thickness measurements with the iVue100 optical coherence tomographer

Background: Accurate assessment of corneal thickness is essential in corneal refractive surgery, contact lens wear and corneal pathology.Aim: To assess the repeatability (intra-observer, inter-observer and inter-session) of central (0 mm – 2 mm), mid-peripheral (2 mm – 5 mm) and peripheral (5 mm – 6 mm) corneal thickness measurements using the iVue 100 spectral domain optical coherence tomographer (SD-OCT).Setting: Optometry Eye Clinic at the University of KwaZulu-Natal (UKZN).Methods: Corneal thickness measurements were taken on 50 healthy participants by two observers independently. A second set of readings was taken by one observer on another session. Repeatability was assessed using Bland–Altman analysis, the intraclass correlation coefficient, coefficient of variation and one-way analysis of variance (ANOVA) analysis.Results: For all corneal regions, the intraclass correlation coefficients for observer one ranged from 0.942 to 0.999 and that for observer two ranged from 0.946 to 0.999, indicating good intra-observer repeatability. Using linear regression, the corneal thickness measurements were found to be comparable (within 1 µm of each other) in all regions with the exception of the nasal and temporal mid-periphery and periphery. The inter-session repeatability was based on the measurements of observer one only with the mean differences ranging from 0.02 µm to 0.63 µm. Linear regression revealed no significant differences between session 1 and session 2 (p &gt; 0.05) except for the measurement of minimum corneal thickness.Conclusion: This study found evidence of good intra-observer, inter-observer and intersession repeatability of central, mid-peripheral and peripheral corneal measurements with the iVue 100 SD-OCT.