Macular Optical Coherence Tomography Scans Research Articles

Optical coherence tomography detection of retinal neural loss in patients with tuberous sclerosis

PurposeTuberous Sclerosis (TS) is a rare, multisystem genetic disease caused by mutations in the TSC1 and TSC2 genes, leading to abnormalities in cell differentiation and proliferation. This study aimed to evaluate the neural integrity of individuals with TS by using Optical Coherence Tomography (OCT) to examine the peripapillary retinal nerve fiber layer (RNFL) thickness and the macular thickness in patients with TS and to compare with healthy controls.MethodsPeripapillary and macular OCT scans (Optopol Revo NX SD OCT) were performed on 41 eyes from 22 TS patients, divided into two groups based on the presence of retinal hamartomas, and compared to 20 eyes from a control group. The average peripapillary RNFL thickness was measured for each quadrant. The macular total thickness and ganglion cell layer (GCL) + inner plexiform layer (IPL) thickness were measured based on the Early Treatment Diabetic Retinopathy Study (ETDRS) map. All measurements were then compared between the groups and controls.ResultsThe TS group showed significantly reduced RNFL thickness and macular thickness when compared to the control group. Specifically, patients with retinal hamartomas exhibited an even more pronounced thinning of both RNFL and macular thickness.ConclusionsThese findings suggest that TS patients undergo significant changes in retinal neurodevelopment and experience axonal loss. This finding may have significant prognostic utility regarding central nervous system degeneration in TS, particularly among patients with retinal hamartomas. OCT may serve as a valuable tool for assessing axonal structural abnormalities in TS patients.Trial Registration Number: Not applicable.

Detecting Fast Progressors: Comparing a Bayesian Longitudinal Model to Linear Regression for Detecting Structural Changes in Glaucoma

PurposeDemonstrate that a novel Bayesian hierarchical spatial longitudinal (HSL) model identifies macular superpixels with rapidly deteriorating ganglion cell complex (GCC) thickness more efficiently than simple linear regression (SLR). DesignProspective cohort study. SettingTertiary glaucoma center. Subjects111 eyes (111 patients) with moderate to severe glaucoma at baseline and ≥4 macular optical coherence tomography scans and ≥2 years of follow-up. Observation ProcedureSuperpixel-patient-specific GCC slopes and their posterior variances in 49 superpixels were derived from our latest Bayesian HSL model and Bayesian SLR. A simulation cohort was created with known intercepts, slopes, and residual variances in individual superpixels. Main outcome measuresWe compared HSL and SLR in the fastest progressing deciles on i) proportion of superpixels identified as significantly progressing in the simulation study and compared to SLR slopes in cohort data; ii) root mean square error (RMSE), and SLR/HSL RMSE ratios. ResultsCohort- In the fastest decile of slopes per SLR, 77% and 80% of superpixels progressed significantly according to SLR and HSL, respectively. The SLR/HSL posterior SD ratio had a median of 1.83, with 90% of ratios favoring HSL. SimulationHSL identified 89% significant negative slopes in the fastest progressing decile vs. 64% for SLR. SLR/HSL RMSE ratio was 1.36 for the fastest decile of slopes, with 83% of RMSE ratios favoring HSL. ConclusionThe Bayesian HSL model improves the estimation efficiency of local GCC rates of change regardless of underlying true rates of change, particularly in fast progressors.

A Bayesian Hierarchical Spatial Longitudinal Model Improves Estimation of Local Macular Rates of Change in Glaucomatous Eyes.

Demonstrate that a novel Bayesian hierarchical spatial longitudinal (HSL) model improves estimation of local macular ganglion cell complex (GCC) rates of change compared to simple linear regression (SLR) and a conditional autoregressive (CAR) model. We analyzed GCC thickness measurements within 49 macular superpixels in 111 eyes (111 patients) with four or more macular optical coherence tomography scans and two or more years of follow-up. We compared superpixel-patient-specific estimates and their posterior variances derived from the latest version of a recently developed Bayesian HSL model, CAR, and SLR. We performed a simulation study to compare the accuracy of intercept and slope estimates in individual superpixels. HSL identified a significantly higher proportion of significant negative slopes in 13/49 superpixels and a significantly lower proportion of significant positive slopes in 21/49 superpixels than SLR. In the simulation study, the median (tenth, ninetieth percentile) ratio of mean squared error of SLR [CAR] over HSL for intercepts and slopes were 1.91 (1.23, 2.75) [1.51 (1.05, 2.20)] and 3.25 (1.40, 10.14) [2.36 (1.17, 5.56)], respectively. A novel Bayesian HSL model improves estimation accuracy of patient-specific local GCC rates of change. The proposed model is more than twice as efficient as SLR for estimating superpixel-patient slopes and identifies a higher proportion of deteriorating superpixels than SLR while minimizing false-positive detection rates. The proposed HSL model can be used to model macular structural measurements to detect individual glaucoma progression earlier and more efficiently in clinical and research settings.

Determining relative thickness of inner retinal layers on single-line foveal optical coherence tomography (OCT) in healthy pediatric eyes—normative data for handheld OCT

Handheld optical coherence tomography (HH-OCT) lacks integrated segmentation/analysis software. Optic neuropathies cause ganglion cell layer (GCL) thinning, with normal to thickened inner nuclear layer (INL), suggesting the potential value of estimating the GCL/INL ratio on single-line foveal HH-OCT scans. This study determines this ratio in macular scans from healthy eyes of young children using HH-OCT and overhead-mounted OCT. Macular OCT scans were obtained using either HH-OCT or overhead-mounted Spectralis FLEX-OCT in children ages 0-5 years undergoing clinically indicated anesthesia/sedation. Exclusion criteria included gestational age <37 weeks, neurologic disease, amblyopia, ocular disease, or large refractive error (spherical equivalent beyond -3.00 D to +8.00 D). For HH-OCT, the GCL and INL were manually measured in pixels from single-line macular scans at the thickest point nasal and temporal to the fovea. For FLEX-OCT images, measurements were aided by automated software. HH-OCT was obtained on 38 eyes (38 children, mean age 2.4 ± 1.8 years) and FLEX-OCT on 56 eyes (56 children, mean age 2.3 ± 1.5 years). Mean nasal GCL/INL was 1.24 ± 0.18 (min/max = 0.92/1.75) for HH-OCT and 1.29 ± 0.18 (min/max = 0.96/1.66) for FLEX-OCT (P = 0.11). Mean temporal GCL/INL was 1.22 ± 0.24 (min/max = 0.66/1.70) for HH-OCT and 1.19 ± 0.16 (min/max = 0.86/1.47) for FLEX-OCT (P = 0.47). Mean normative GCL/INL ratios were approximately 1.2 at the thickest macular areas both nasal and temporal to the fovea, with either HH-OCT or FLEX-OCT in young children's eyes. These values may prove useful when HH-OCT is used to assess optic neuropathies, in which the GCL/INL ratio is expected to be decreased.

Spontaneous closure of full-thickness macular hole after pars plana vitrectomy for retinal detachment: evidence of ellipsoid zone restoration.

To describe a case of full-thickness macular hole (FTMH) occurred after pars plana vitrectomy (PPV) for a macula-sparing rhegmatogenous retinal detachment (RRD), which showed a spontaneous closure associated with outer retinal layers restoration. Case report. A pseudophakic 69-year-old man underwent PPV for a macula-sparing superior RRD in the right eye (RE). Best corrected visual acuity (BCVA) was 20/20 before surgery. Three weeks after treatment the patient complained about visual impairment, and a FTMH was detected at fundus examination as well as confirmed by optical coherence tomography (OCT) scan. The patient was scheduled for a repeated surgery, but FTMH spontaneously closed eighteen days after its occurrence as demonstrated at OCT showing only a point break of the ellipsoid zone (EZ) and Verhoeff membrane. The subsequent macular OCT scan showed a point-like irregularity at the Verhoeff membrane and regeneration of EZ, associated with a progressive improvement in BCVA. Forty-days after the FTMH occurrence, all the retinal layers were completely restored with a complete clinical recovery. FTMH formation and closure after macula-sparing RRD repair is a rare event that could be characterized by spontaneous and gradual anatomical restoration of the EZ associated with visual acuity improvement, underlying the retinal physiology recovery.

STRAWBERRY RETINA: SILICONE OIL-RETINA INTERFACE ON MULTIMODAL IMAGING.

To report a new photographic macular feature identified on multimodal imaging in eyes with silicone oil in situ. Retrospective, observational case series of three eyes of three patients. Two eyes had undergone initial vitrectomy for vitreous hemorrhage with fibrovascular membranes causing tractional retinal detachments secondary to retinovascular occlusion. One eye had further vitrectomy for rhegmatogenous retinal detachment complicated with proliferative vitreoretinopathy. All three eyes had multiple, discrete, coarse, hyperreflective deposits at the silicone oil-retina interface on optical coherence tomography macular scans, with increased reflectivity from the inner retinal layers. On multicolor and infrared images, these preretinal deposits produced hyporeflective darker spots giving a quasi-pitting appearance of the retinal surface against glossy bright reflection from silicone oil, thus simulating an appearance of ‟a strawberry." These deposits are causing inverse pitting of the oil bubble. On blue autoflourescence imaging, the preretinal deposits caused hypoautoflourescence. Partial silicone oil emulsification was seen superiorly in two of these patients with a different clinical and optical coherence tomography appearance from these hyperreflective macular deposits. We describe a new distinctive ‟Strawberry Retina" appearance identified on multicolor and infrared macular images associated with hyperreflective, coarse deposits at the silicone oil-retina interface.

Static Perimetry in the Rate of Progression in USH2A-related Retinal Degeneration (RUSH2A) Study: Assessment Through 2 Years

To evaluate disease progression using static perimetry (SP) in patients with USH2A-related retinal degeneration, including Usher syndrome type 2 (USH2) and nonsyndromic autosomal recessive retinitis pigmentosa. Prospective, observational cohort study. A total of 102 patients with biallelic disease-causing sequence variants in USH2A with baseline best-corrected visual acuity (BCVA) letter score ≥54 were recruited from 16 clinical sites in Europe and North America. SP, BCVA, full-field stimulus thresholds, spectral domain optical coherence tomography macular scans, and fundus-guided mesopic microperimetry were performed at baseline and annually. The main outcome measures were total hill of vision (VTOT), hill of vision in the central 30° (V30), VTOT minus V30 (VPERIPH), and mean sensitivity. The average decline (95% CI) was 2.05 (1.40, 2.70) decibel-steradian (dB-sr)/y for VTOT, 0.48 (0.32, 0.65) dB-sr/y for V30, 1.53 (0.97, 2.08) dB-sr/y for VPERIPH, and 0.55 (0.40, 0.71) dB/y for mean sensitivity. Average percentage decline per year was 8.3 (5.5, 11.1) for VTOT, 5.2 (3.0, 7.4) for V30, 16.0 (9.5, 22.0) for VPERIPH, and 5.1 (3.5, 6.7) for mean sensitivity. Changes from baseline to year 2 in all SP measures were highly correlated (r's ranging from 0.52 [V30 vs VPERIPH] to 0.98 [VTOT vs VPERIPH]). Quantitative measures of SP declined significantly over 2 years in USH2A-related retinal degeneration. The annual percentage rate of change was greatest for VTOT and VPERIPH, whereas V30 and mean sensitivity changed least, reflecting earlier and more severe peripheral degeneration compared with central loss.

Comparison of Ganglion Cell Layer and Inner Plexiform Layer Rates of Change in Suspected and Established Glaucoma

We compared ganglion cell layer (GCL) and inner plexiform layer (IPL) rates of change (RoC) in patients with glaucoma suspect (GS) and established glaucoma (EG) to test the hypothesis that IPL thickness changes would occur earlier than GCL changes in eyes with early damage. Prospective, cohort study. A total of 64 GS eyes (46 patients) and 112 EG eyes (112 patients) with ≥2 years of follow-up and ≥3 macular optical coherence tomography scans were included. GCL and IPL superpixel thickness measurements were exported. A Bayesian hierarchical model with random intercepts/slopes and random residual variances was fitted to estimate RoC in individual superpixels. Normalized RoC and proportions of superpixels with significantly negative and positive GCL and IPL RoC were compared within the groups. The average (SD) follow-up time and number of scans were 3.5 (0.7) years and 4.2 (1.0), respectively, in the GS group and 3.6 (0.4) years and 7.3 (1.1) in the EG group. Mean (SD) normalized RoC was faster for GCL than IPL (-0.69 [0.05] vs -0.33 [0.04]) in the GS group, whereas it was faster for IPL (-0.47 [0.03] vs -0.28 [0.02]) in EG eyes. GCL RoC were significantly negative in 24 of 36 superpixels compared with 8 of 36 for IPL (P < .001) in GS eyes. In the EG group, 23 of 36 superpixels had significant negative IPL RoC compared with 13 of 36 superpixels for GCL (P=.006). GCL thickness is more likely to demonstrate change over time compared with IPL in glaucoma suspects. There is no evidence of preferential IPL thinning in eyes with suspected early glaucoma damage.

Association Between Rate of Ganglion Cell Complex Thinning and Rate of Central Visual Field Loss

Whether rapid ganglion cell complex (GCC) thinning during an initial follow-up period is associated with rates of central visual field loss over time is unclear but important to understand because risk of glaucoma progression can help guide treatment intensity. To investigate the association between the rate of GCC thinning during initial follow-up and the rate of central visual field loss. This retrospective cohort study assessed patients older than 18 years with glaucoma at a tertiary glaucoma center who were followed up from June 18, 2014, to January 11, 2019. Data analysis for the current study was undertaken in March 2022. Initial rates of GCC thinning were obtained from global GCC thickness values of the first 3 optical coherence tomography (OCT) scans. Rates of central visual field loss were assessed as the change in central (10-2) visual field mean deviation during the 4.7-year follow-up period by univariable and multivariable linear mixed-effects models. Eyes were categorized as slow (>-1 μm/y) or fast (≤-1 μm/y) progressors based on rates of GCC thinning. The cohort consisted of 202 eyes of 139 patients (mean [SD] age, 68.7 [10.0] years; 72 male [51.8%]); 44 African American patients (31.7%), 13 Asian patients (9.4%), 80 White patients (57.6%), and 2 patients who identified as other race and ethnicity (1.4%) were analyzed. The rate of GCC change was -0.56 μm/y (95% CI, -0.66 to -0.46 μm/y) during a mean initial follow-up of 1.8 years (95% CI, 1.7-2.0 years). A total of 163 eyes (80.7%) were slow OCT progressors, and 39 (19.3%) were fast OCT progressors, with rates of GCC thinning of -0.3 μm/y (95% CI, -0.4 to -0.2 μm/y) and -1.6 μm/y (-1.8 to -1.3 μm/y), respectively. The rates of 10-2 visual field mean deviation worsening among slow and fast OCT progressors were -0.10 dB/y (95% CI, -0.16 to 0.00 dB/y) and -0.34 dB/y (95% CI, -0.51 to -0.16 dB/y), respectively (difference, -0.26 dB/y; 95% CI, -0.45 to -0.07 dB/y; P = .008). In this cohort study, rapid GCC thinning during an initial follow-up period was associated with faster rates of central visual field decline. These findings support use of longitudinal macular OCT scans assisting clinical decision-making for glaucoma and also may guide possible intensification of therapy in high-risk patients.

New Findings in Early-Stage Keratoconus: Lamina Cribrosa Curvature, Retinal Nerve Fiber Layer Thickness, and Vascular Perfusion

PurposeOur aim was to investigate the involvement of posterior pole structures in eyes affected by keratoconus (KC). Optical coherence tomography (OCT) and OCT angiography (OCTA) were used to determine the status of lamina cribrosa (LC), peripapillary retinal nerve fiber layer (RNFL), macular and peripapillary microvasculature. DesignObservational, cross-sectional, case-control analysis. MethodsSingle-center investigation involving patients with KC and healthy control subjects. Enrolled subjects underwent anterior segment OCT combined with Placido-disk topography, macular and optic nerve head swept-source OCT and swept-source OCTA scans, and 3D wide glaucoma module for peripapillary RNFL thickness measurement. The LC curvature index was used to express the degree of LC posterior bowing. We calculated the vessel density and vessel length density at the macular superficial capillary plexus, deep capillary plexus, choriocapillaris, and nerve radial peripapillary capillary plexus. ResultsOverall, 32 eyes with KC and an equal number of age- and axial length–matched control eyes were included in the analysis. Almost all (97%) of eyes with KC were classified as early stage. KC displayed a reduction in peripapillary RNFL thickness (104.8 ± 11.9 µm vs 110.7 ± 10.5 µm; P = .039) and nerve radial peripapillary capillary plexus vessel density (46.31% ± 3% vs 43.82% ± 4%; P = .006) when compared with control subjects; these differences were more evident in the temporal sector and were associated with a higher LC curvature index (9.9% ± 2.6% vs 8.48% ± 1.7%; P = .012). Mean macular superficial capillary plexus vessel density was 3 percentage points lower in eyes with KC than in healthy controls (P < .001). ConclusionEarly-stage KC may be characterized by a posterior bowing of the LC along with a subtle peripapillary RNFL thinning and vascular impairment. These findings support the hypothesis that KC may be a corneal manifestation of a more generalized “eye collagen disease.”

THE TARGET SIGN: A Near Infrared Feature and Multimodal Imaging in a Pluri-Ethnic Cohort with RDH5-Related Fundus Albipunctatus.

Retinol dehydrogenase 5 (RDH5)-related fundus albipunctatus can present with phenotypic variability. Our purpose was to investigate new clinical characteristics and multimodal imaging findings in patients from different ethnic origins, carrying different mutations. Multicenter international retrospective case series of 18 patients with genetically confirmed RDH5-related fundus albipunctatus. Patients' files were reviewed for fundus images, visual acuity, macular optical coherence tomography scans, near-infrared images, fundus autofluorescence, electroretinogram, and genetic mutations. Imaging and electroretinogram findings. All eyes (n = 36, 100%) showed small circular findings seen on near-infrared images, termed as the "target sign," correlating to the yellowish dots seen clinically and to the distinct hyperreflective linear lesions on optical coherence tomography at the level between external limiting membrane and retinal pigment epithelium. Perifoveal atrophy with foveal sparing was seen in 4 eyes of 2 patients (both RDH5-c.160C>T, p.R54X mutation). Fundus autofluorescence revealed small hyperautofluorescent dots (n = 16, 44.4%). Scotopic electroretinograms were significantly reduced in all cases with an electronegative pattern, 66.7% displayed cone dysfunction. Our results show distinct imaging findings present in all patients with fundus albipunctatus independent of ethnicity or genetic mutation. Our results can facilitate the current algorithm to diagnose RDH5-related fundus albipunctatus and allow for targeted genetic testing.

Association Between Ganglion Cell Complex Thinning and Vision-Related Quality of Life in Glaucoma

Faster structural changes may be associated with worse vision-related quality of life in patients with glaucoma. To evaluate the association between the rate of ganglion cell complex thinning and the Vision Function Questionnaire in glaucoma. This retrospective analysis of a longitudinal cohort was designed in October 2021. Patients were enrolled from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study. Two hundred thirty-six eyes of 118 patients with diagnosed or suspected glaucoma were followed up with imaging for a mean of 4.1 years from September 2014 to March 2020. The Vision Function Questionnaire was evaluated using the 25-item National Eye Institute Visual Function at the last follow-up visit. Ganglion cell complex thickness was derived from macular optical coherence tomography scans and averaged within 3 circular areas (3.4°, 5.6°, and 6.8° from the fovea) and superior and inferior hemiregions. Linear mixed-effects models were used to investigate the association between the rate of ganglion cell complex thinning and Rasch-calibrated Vision Function Questionnaire score. The mean (SD) age was 73.2 (8.7) years, 65 participants (55.1%) were female, and 53 participants (44.9%) were African American. Race was self-reported by the participants. Mean composite Rasch-calibrated National Eye Institute Visual Function Questionnaire score was 50.3 (95% CI, 45.9-54.6). A faster annual rate of global ganglion cell complex thinning in the better eye was associated with a higher disability reflected by the composite National Eye Institute Visual Function Questionnaire score (-15.0 [95% CI, -28.4 to -1.7] per 1 μm faster; P = .03). When stratified by degrees from the fovea, the 5.6° and 6.8° areas were associated with the composite National Eye Institute Visual Function Questionnaire Rasch-calibrated score (-14.5 [95% CI, -27.0 to -2.0] per 1 μm faster; R2 = 0.201; P = .03; and -23.7 [95% CI, -45.5 to -1.9] per 1 μm faster; R2 = 0.196; P = .02, respectively), and -8.0 (95% CI, -16.8 to 0.8) per 1 μm faster for the 3.4° area (R2 = 0.184; P = .07) after adjusting for confounding factors. These findings suggest that faster and sectoral central location of ganglion cell complex thinning provides useful information in determining the risk of vision-related quality of life in glaucoma. Monitoring macular structure may be useful for determining the risk of functional impairment in glaucoma.

Incidence of eye complications among sickle cell disease patients in Jeddah, Saudi Arabia: A cross-sectional study

IntroductionSickle cell disease (SCD) is a heritable blood disorder resulting in deformed, rigid red blood cells, rendering them more prone to vaso-occlusion. Ocular complications are known to affect multiple organs through the body's vasculature. Here, we evaluated the incidence of eye complications in patients with SCD at King Abdulaziz Medical City in Jeddah, Saudi Arabia. Materials and methodsWe used a cross-sectional approach and collected relevant medical data from nine patients with SCD. Ophthalmic assessment included visual acuity and an in-clinic dilated fundus examination. All patients were asked to attend the ophthalmology clinic to undergo optical coherence tomography (OCT) angiography, macular OCT scan, and fundus photography. The results of the imaging tests were interpreted by a certified ophthalmology consultant specializing in retinal diseases. Descriptive analyses of the results were also performed. ResultsThe mean age of the nine patients was 24.78 ± 10.9 years. All patients were non-hypertensive, one had type 1 diabetes, and another had type 2 diabetes. Five patients had normal visual acuity, two had slight impairments in at least one eye, and two had moderate impairment in at least one eye. One of the nine patients exhibited retinal ischemia in the right eye despite normal macular thickness (visual acuity, OD, 6/30; OS, 6/21). The remaining eight patients showed no ocular abnormalities. ConclusionOf the nine patients with SCD, five showed no symptoms of ocular complications. One patient showed retinal ischemia in the right eye, despite a normal macular thickness. This study's results suggest routine ophthalmologic examination may not be able to detect or monitor macular or retinal abnormalities unless augmented with detailed imaging techniques.

No optical coherence tomography changes in premanifest Huntington's disease mutation carriers far from disease onset

BackgroundSpectral‐domain optical coherence tomography (OCT) may detect retinal changes as a biomarker in neurodegenerative diseases like manifest Huntington's disease (HD). We investigate macular retinal layer thicknesses in a premanifest HD (pre‐HD) cohort and healthy controls (HC).MethodsPre‐HD mutation carriers underwent standardized ratings and a preset macular OCT scan. Thickness values were determined for each sector of all macular retinal layers, the mean of all sectors and the mean of the inner ring (IR, 3 mm) after segmentation (Heyex segmentation batch). HC were retrospectively included from an existing database. The IR thickness of the ganglion cell layer (GCL), retinal nerve fiber layer (RNFL), GCL + inner plexiform layer (GCIPL), and total retina were included in the exploratory correlation analyses with paraclinical ratings and compared to HC.ResultsThe analyses comprised n = 24 pre‐HD participants (n = 10 male, n = 14 female) and n = 38 HC (n = 14 male, n = 24 female). Retinal layer parameters did not correlate with paraclinical ratings. Expected correlations between established HD biomarkers were robust. The IR thicknesses of the GCL, GCIPL, and total retina did not differ between pre‐HD and HC. The IR thickness of the RNFL was significantly higher in pre‐HD participants (pre‐HD: 23.22 μm (standard deviation 2.91), HC: 21.26 μm (1.90), p = .002).DiscussionIn this cross‐sectional cohort of genetically determined pre‐HD participants, neurodegenerative features were not detected with retinal layer segmentation. Since our pre‐HD collective was more than 16 years before disease onset, OCT may not be sensitive enough to detect early changes.

OCT Assisted Quantification of Vitreous Inflammation in Uveitis.

PurposeVitreous haze (VH) is a key marker of inflammation in uveitis but limited by its subjectivity. Optical coherence tomography (OCT) has potential as an objective, noninvasive method for quantifying VH. We test the hypotheses that OCT can reliably quantify VH and the measurement is associated with slit-lamp based grading of VH.MethodsIn this prospective study, participants underwent three repeated OCT macular scans to evaluate the within-eye reliability of the OCT vitreous intensity (VI). Association between OCT VI and clinical findings (including VH grade, phakic status, visual acuity [VA], anterior chamber cells, and macular thickness) were assessed.ResultsOne hundred nineteen participants were included (41 healthy participants, 32 patients with uveitis without VH, and 46 patients with uveitis with VH). Within-eye test reliability of OCT VI was high in healthy eyes and in all grades of VH (intraclass correlation coefficient [ICC] > 0.79). Average OCT VI was significantly different between healthy eyes and uveitic eyes without and uveitic eyes with VH, and was associated with increasing clinical VH grade (P < 0.05). OCT VI was significantly associated with VA, whereas clinical VH grading was not. Cataract was also associated with higher OCT VI (P = 0.03).ConclusionsOCT VI is a fast, noninvasive, objective, and automated method for measuring vitreous inflammation. It is associated with clinician grading of vitreous inflammation and VA, however, it can be affected by media opacities.Translational RelevanceOCT imaging for quantifying vitreous inflammation shows high within-eye repeatability and is associated with clinical grading of vitreous haze. OCT measurements are also associated with visual acuity but may be affected by structures anterior to the acquisition window, such as lens opacity and other anterior segment changes.

A normative database of A-scan data using the Heidelberg Spectralis Spectral Domain Optical Coherence Tomography machine.

PurposeTo develop the first normative database of macular and circumpapillary scans with reference values at the level of the A-scan using the Heidelberg Spectralis Optical Coherence Tomography (OCT) machine.MethodsThis study is a retrospective cross sectional analysis of macular and circumpapillary OCT scans of healthy individuals. All participants had a full ophthalmic examination, including best corrected visual acuity, intraocular pressure, biomicroscopy, posterior segment examination and OCT scan. The volume and thickness of each of the nine Early Treatment Diabetic Retinopathy zones at the macula were analysed for the total retinal thickness, retinal nerve fibre layer (RNFL), ganglion cell layer (GCL) and inner plexiform layer (IPL). The thickness of the circumpapillary RNFL was analysed at the disc. Associations between age, gender, refractive error and OCT measurements were explored. De-identified A-scans were extracted from the OCT machine as separate tab-separated text file and made available according to the data sharing statement.ResultsTwo-hundred eyes from 146 participants were included of which 69 (47%) were female. The mean age (SD) was 48.52 (17.52). Participants were evenly distributed across four age groups and represented nine broad ethnic groups in proportions comparable to the local distribution. All the macular scans were 20° x 20° (5.9 mm x 5.9 mm), with a total scan density between 12,800 and 49,152 A-scans. The peripapillary scans were all 12° (3.5 mm), at a scan density of 768 A-scans. The mean retinal, GCL and IPL volumes were significantly greater in males than females. Mean peripapillary RNFL thickness did not differ significantly between males and females. Age and total retinal volume (r = –0.2561, P = 0.0003), GCL volume (–0.2911, P < 0.0001) and IPL volume (–0.3194, P < 0.0001) were negatively correlated. The IPL had the strongest three significant negatively associated segments; superior inner IPL (r = –0.3444, P < 0.0001), nasal outer IPL (r = –0.3217, P < 0.0001) and inferior inner IPL (r = –0.3179, P < 0.0001). The temporal inner macular RNFL showed a statistically significant positive correlation (r = 0.1929, P = 0.0062) with age. The only significant association between age and thickness at the peripapillary disc scan was the superior temporal sector (r = –0.1910, P = 0.0067). All retinal layers were negatively correlated for refractive error, except for the central RNFL which was positively correlated (r = 0.1426, P = 0.044).ConclusionThis study provides a normative database of macular and circumpapillary scans with reference values at the level of the A-scan using the Heidelberg Spectralis Optical Coherence Tomography (OCT) machine.

Automated segmentation of choroidal layers from 3-dimensional macular optical coherence tomography scans

BackgroundChanges in choroidal thickness are associated with various ocular diseases, and the choroid can be imaged using spectral-domain optical coherence tomography (SD-OCT) and enhanced depth imaging OCT (EDI-OCT). New methodEighty macular SD-OCT volumes from 80 patients were obtained using the Zeiss Cirrus machine. Eleven additional control subjects had two Cirrus scans done in one visit along with enhanced depth imaging (EDI-OCT) using the Heidelberg Spectralis machine. To automatically segment choroidal layers from the OCT volumes, our graph-theoretic approach was utilized. The segmentation results were compared with reference standards from two independent graders, and the accuracy of automated segmentation was calculated using unsigned/signed border positioning/thickness errors and Dice similarity coefficient (DSC). The repeatability and reproducibility of our choroidal thicknesses were determined by intraclass correlation coefficient (ICC), coefficient of variation (CV), and repeatability coefficient (RC). ResultsThe mean unsigned/signed border positioning errors for the choroidal inner and outer surfaces are 3.39 ± 1.26 µm (mean ± standard deviation)/− 1.52 ± 1.63 µm and 16.09 ± 6.21 µm/4.73 ± 9.53 µm, respectively. The mean unsigned/signed choroidal thickness errors are 16.54 ± 6.47 µm/6.25 ± 9.91 µm, and the mean DSC is 0.949 ± 0.025. The ICC (95% confidence interval), CV, RC values are 0.991 (0.977–0.997), 2.48%, 14.25 µm for the repeatability and 0.991 (0.977–0.997), 2.49%, 14.30 µm for the reproducibility studies, respectively. Comparison with existing method(s)The proposed method outperformed our previous method using choroidal vessel segmentation and inter-grader variability. ConclusionsThis automated segmentation method can reliably measure choroidal thickness using different OCT platforms.

The Additive Value of Foveal OCT-Based Biometry to Fundus Biomicroscopy for Detecting Macular Pathology Prior to Cataract Surgery

To assess the additive value of foveal swept-source optical coherence tomography (OCT)-based biometry to the preoperative fundus examinations for diagnosing macular abnormalities in patients scheduled for cataract surgery. Diagnostic testing evaluation. Consecutive patients 50 years of age and older planned for cataract surgery from one institution were retrospectively enrolled. All patients underwent foveal swept-source OCT, and macular spectral domain (SD) OCT scans before pupil dilation as well as dilated fundus biomicroscopy examination. The effectiveness of fundus biomicroscopy examinations, foveal swept-source OCT scans, and the combination of both in identifying macular diseases was analyzed with macular spectral-domain OCT scans as reference. Seventy-eight of the eligible 442 eyes (442 patients) were excluded because of noninterpretable macular spectral-domain OCT OCT scans or foveal swept-source OCT scans. The remaining 364 eyes of 364 patients (mean age 73.59±9.26 years [range 49-96], 172 males) formed the study group. Fundus biomicroscopy alone vs fundus biomicroscopy with the addition of foveal swept-source OCT yielded 36% vs 63% sensitivity, 94% vs 72% specificity, 79% vs 58% positive predictive value (PPV), and 71% vs 76% negative predictive value (NPV), respectively. This diagnostic improvement was significant compared with fundus biomicroscopy alone (P=2.98-8). Combined fundus biomicroscopy and foveal swept-source OCT scans improved the detection of macular abnormalities prior to cataract surgery but it was inferior to macular spectral-domain OCT scans. Additional studies to assess the cost-effectiveness of adding foveal swept-source OCT scan in comparison to macular spectral-domain OCT scan to the preoperative cataract evaluation are required.

Serum neurofilament levels reflect outer retinal layer changes in multiple sclerosis.

Background:Serum neurofilament light chain (sNfL) and distinct intra-retinal layers are both promising biomarkers of neuro-axonal injury in multiple sclerosis (MS). We aimed to unravel the association of both markers in early MS, having identified that neurofilament has a distinct immunohistochemical expression pattern among intra-retinal layers.Methods:Three-dimensional (3D) spectral domain macular optical coherence tomography scans and sNfL levels were investigated in 156 early MS patients (female/male: 109/47, mean age: 33.3 ± 9.5 years, mean disease duration: 2.0 ± 3.3 years). Out of the whole cohort, 110 patients had no history of optic neuritis (NHON) and 46 patients had a previous history of optic neuritis (HON). In addition, a subgroup of patients (n = 38) was studied longitudinally over 2 years. Support vector machine analysis was applied to test a regression model for significant changes.Results:In our cohort, HON patients had a thinner outer plexiform layer (OPL) volume compared to NHON patients (B = −0.016, SE = 0.006, p = 0.013). Higher sNfL levels were significantly associated with thinner OPL volumes in HON patients (B = −6.734, SE = 2.514, p = 0.011). This finding was corroborated in the longitudinal subanalysis by the association of higher sNfL levels with OPL atrophy (B = 5.974, SE = 2.420, p = 0.019). sNfL levels were 75.7% accurate at predicting OPL volume in the supervised machine learning.Conclusions:In summary, sNfL levels were a good predictor of future outer retinal thinning in MS. Changes within the neurofilament-rich OPL could be considered as an additional retinal marker linked to MS neurodegeneration.

Structure-Function Analysis in Macular Drusen With Mesopic and Scotopic Microperimetry.

PurposeTo investigate the structure–function relationship in eyes with drusen with mesopic and scotopic microperimetry.MethodsWe analyzed structural and functional data from 43 eyes with drusen. Functional data were acquired with mesopic and scotopic two-color (red and cyan) microperimetry. Normative values were calculated using data from 56 healthy eyes. Structural measurements were green autofluorescence and dense macular optical coherence tomography scans. The latter were used to calculate the retinal pigment epithelium elevation (RPE-E) and the photoreceptor reflectivity ratio (PRR). The pointwise structure–function relationship was measured with linear mixed models having the log-transformed structural parameters as predictors and the sensitivity loss (SL, deviation from normal) as the response variable.ResultsIn the univariable analysis, the structural predictors were all significantly correlated (P < 0.05) with the SL in the mesopic and scotopic tests. In a multivariable model, mesopic microperimetry yielded the best structure–function relationship. All predictors were significant (P < 0.05), but the predictive power was weak (best R2 = 0.09). The relationship was improved when analyzing locations with abnormal RPE-E (best R2 = 0.18).ConclusionsMesopic microperimetry shows better structure–function relationship compared to scotopic microperimetry; the relationship is weak, likely due to the early functional damage and the small number of tested locations affected by drusen. The relationship is stronger when locations with drusen are isolated for the mesopic and scotopic cyan test.Translational RelevanceThese results could be useful to devise integrated structure–function methods to detect disease progression in intermediate age-related macular degeneration.