Outer Retinal Layer Thickness Research Articles

Multimodal in-vivo maps as a tool to characterize retinal structural biomarkers for progression in adult-onset Stargardt disease

PurposeTo characterize retinal structural biomarkers for progression in adult-onset Stargardt disease from multimodal retinal imaging in-vivo maps.MethodsSeven adult patients (29–69 years; 3 males) with genetically-confirmed and clinically diagnosed adult-onset Stargardt disease and age-matched healthy controls were imaged with confocal and non-confocal Adaptive Optics Scanning Light Ophthalmoscopy (AOSLO), optical coherence tomography (OCT), fundus infrared (FIR), short wavelength-autofluorescence (FAF) and color fundus photography (CFP). Images from each modality were scaled for differences in lateral magnification before montages of AOSLO images were aligned with en-face FIR, FAF and OCT scans to explore changes in retinal structure across imaging modalities. Photoreceptors, retinal pigment epithelium (RPE) cells, flecks, and other retinal alterations in macular regions were identified, delineated, and correlated across imaging modalities. Retinal layer-thicknesses were extracted from segmented OCT images in areas of normal appearance on clinical imaging and intact outer retinal structure on OCT. Eccentricity dependency in cell density was compared with retinal thickness and outer retinal layer thickness, evaluated across patients, and compared with data from healthy controls.ResultsIn patients with Stargardt disease, alterations in retinal structure were visible in different image modalities depending on layer location and structural properties. The patients had highly variable foveal structure, associated with equally variable visual acuity (-0.02 to 0.98 logMAR). Cone and rod photoreceptors, as well as RPE-like structures in some areas, could be quantified on non-confocal split-detection AOSLO images. RPE cells were also visible on dark field AOSLO images close to the foveal center. Hypo-reflective gaps of non-waveguiding cones (dark cones) were seen on confocal AOSLO in regions with clinically normal CFP, FIR, FAF and OCT appearance and an intact cone inner segment mosaic in three patients.ConclusionDark cones were identified as a possible first sign of retinal disease progression in adult-onset Stargardt disease as these are observed in retinal locations with otherwise normal appearance and outer retinal thickness. This corroborates a previous report where dark cones were proposed as a first sign of progression in childhood-onset Stargardt disease. This also supports the hypothesis that, in Stargardt disease, photoreceptor degeneration occurs before RPE cell death.

Early Single-Examination Optical Coherence Tomography Biomarkers for Treatment-Requiring Retinopathy of Prematurity.

Optical coherence tomography (OCT) is an emerging adjunct imaging modality to evaluate retinopathy of prematurity (ROP). From an 11-year research database, we identify early OCT biomarkers that predict treatment-requiring ROP (TR-ROP). For preterm infants with acceptable OCT images at 32 ± 1weeks postmenstrual age (PMA), we extracted the following measures: total retina, inner retinal layer (IRL), and outer retinal layer (ORL) thicknesses at the fovea and the parafovea, inner nuclear layer (INL) and choroidal thickness, parafovea/fovea (P/F) ratio, and presence of macular edema. Using univariable and multivariable logistic regression models, we evaluated the association between retinal and choroidal OCT measurements at 32 ± 1weeks PMA and development of TR-ROP. Of 277 eyes (145 infants) with usable OCT images, 67 eyes had TR-ROP. Lower P/F ratio (P<0.0001), thicker foveal IRL (P=0.0001), and thinner choroid (P=0.03) were associated with TR-ROP in univariable analysis, but lost significance of association when adjusted for gestational age and race. Absence of macular edema was associated with TR-ROP when adjusted for gestational age and race (P=0.01). In 185 eyes without macular edema, P/F ratio was associated with TR-ROP in both univariable analysis (P<0.0001) and multivariable analysis (P=0.02) with adjustment for gestational age and race. Presence of macular edema at 32 ± 1weeks PMA in infants with lower gestational age may be protective against TR-ROP. In infants without macular edema, P/F ratio may be an early OCT biomarker for development of TR-ROP. Incorporation of early OCT biomarkers may be useful in prediction of TR-ROP.

Relationship between automated choroidal thickness measurements and retinal sensitivity using microperimetry in patients with myopia and different stages of myopic maculopathy

PurposeTo assess the relationship between macular choroidal thickness (CT) measurements and retinal sensitivity (RS) in eyes with myopia and different stages of myopic maculopathy.MethodsA masked, cross-sectional, and consecutive study involving patients with emmetropia/myopia (control group) and high myopia (HM) eyes. Automated choroidal thickness (CT) and manual outer retinal layer (ORL) thickness were acquired using swept-source optical coherence tomography, while retinal sensitivity (RS) assessed by microperimetry (MP3) in all regions of the macular Early Treatment Diabetic Retinopathy Study (ETDRS) grid. Comparisons were made between groups, and correlations were performed among these measurements, demographic and ocular parameters and myopic maculopathy classification.ResultsA total of 37 (74 eyes) patients were included in the study. The mean age was 39 ± 13 years, and 28 patients (76%) were female. HM eyes exhibited inferior best-corrected visual acuity and a more advanced myopic maculopathy classification compared to the control group. The mean macular CT were 255 and 179 μm in the control and HM eyes (P < 0.001), respectively. In the HM eyes, superior ETDRS region presented the greatest values. Mean RS in control and HM groups was 28 and 24 dB (P = 0.001), respectively. Inner temporal followed by superior, were the regions of higher RS. Mean ORL thickness was 83 and 79 μm (P < 0.001), in the control and HM groups, respectively. The inner temporal ETDRS region presented the thickest measure. CT correlated significantly with RS (r = 0.41, P < 0.001) and ORL thickness, (r = 0.58, P < 0.001), which also correlated with RS (r = 0.40, P < 0.001). Spherical equivalent, axial length and myopic maculopathy stage were the parameters that most correlated with CT, RS and ORL thickness. For every 100 μm increase in thickening of CT there was an average increase of 3.4 μm in ORL thickness and 2.7 dB in RS. Myopic maculopathy classification demonstrated influence only with CT.ConclusionMyopia degree is related to ORL and choroidal thinning and deterioration of retinal sensitivity in some ETDRS regions of the macula. Choroidal thinning is associated to with a decline of retinal sensitivity, thinning of ORL, and worsening of myopic maculopathy classification, so new treatments are necessary to prevent myopia progression.

OCT risk factors for 2-year foveal involvement in non-treated eyes with extrafoveal geographic atrophy and AMD.

To assess the relationship of optical coherence tomography (OCT) findings and progression to foveal atrophy in a cohort of eyes with extrafoveal geographic atrophy (GA) and age-related macular degeneration (AMD) at inclusion. We retrospectively analyzed 45 participants (45 eyes) with extrafoveal GA at baseline and with 2years of regular follow-ups. Several OCT qualitative features (i.e., presence of foveal flat pigment epithelium detachment with a thin double layer sign [DLS] and reticular pseudodrusen, GA focality) and quantitative measurements (outer retinal layer thickness, retinal pigment epithelium [RPE] to Bruch's membrane [BM] volume, minimum distance from the central foveal circle, and untransformed GA lesion size area) were assessed at baseline. Logistic regression analyses were carried out to identify independent significant predictors and compute odds ratios (ORs) for the risk of the development of atrophy. At month 24, 26 eyes (57.8%) developed atrophy in the foveal central circle, while 11 eyes (24.4%) developed atrophy in the foveal central point. Significant independent predictive features for the development of atrophy in the foveal central circle included foveal outer retinal thickness (OR, 0.867; p = 0.015), minimum distance from the foveal central circle (OR, 0.992; p = 0.022), and foveal thin DLS (OR, 0.044; p = 0.036). The only independent predictive feature for the development of atrophy in the foveal central point was the presence of foveal thin DLS (OR, 0.138; p = 0.017). We identified OCT risk factors for 2-year foveal atrophy in eyes with untreated extrafoveal GA at baseline.

Relationships between regional retinal sensitivities assessed by microperimetry and their corresponding retinal layer thicknesses in healthy middle‐aged subjects

Aims/Purpose: To investigate relationships between regional differential light sensitivity (DLS) and inner and outer retinal layer (IRL and ORL) thicknesses in healthy middle‐aged adults.Methods: Measurements were made in 42 eyes of 42 healthy individuals of mean age 51.3 ± 5.4 years (range 40–59 years), spherical equivalent (SE) between ±3.50 D and good visual acuity. Mesopic fundus‐controlled perimetry was used to measure regional DLS. Spectral‐domain optical coherence tomography (SD‐OCT) was used to measure IRL (ganglion cell‐related layer) and ORL thicknesses. DLS and retinal thickness measurements were recorded for five subfields: central fovea (1 mm diameter) and the quadrants temporal, nasal, superior, and inferior of a parafoveal ring of outer diameter 3 mm and inner diameter 1 mm. Relationships between regional DLS and corresponding IRL and ORL thicknesses were assessed through univariate and multivariate analysis.Results: Mean DLS measured in the inferior parafoveal ring quadrant was significantly correlated with mean IRL thickness (rho = −0.50; p = 0.0045). This correlation was negative, meaning that a thicker IRL was related to a worse DLS. No significant correlations emerged between mean DLS and corresponding ORL or IRL thicknesses for the other subfields. Subsequent forward stepwise multiple linear regression analysis to correct for potential confounding factors revealed that IRL thickness and SE emerged as significant predictors of DLS in the inferior quadrant (R2 model = 33%; p = 0.0004).Conclusions: A thicker macular IRL, possibly indicating transient gliosis, was associated with a worse DLS in healthy middle‐aged eyes.

Outer Retinal and Choroidal Changes in Adolescents with Long-Lasting Type 1 Diabetes.

This study aimed to assess outer retinal layer (ORL), retinal pigment epithelium (RPE), choroid (Ch) and choriocapillaris (CC) modifications in adolescents with long-lasting (>10 years) type 1 diabetes (T1D) without (noDR) or with diabetic retinopathy (DR). ORL and RPE thickness were measured at optical coherence tomography (OCT) macular scans. Vascular parameters of Ch and CC were quantified after elaboration of macular OCT-angiography (OCTA) images. Insulin dose and auxological and metabolic parameters were correlated with OCT and OCTA findings in patients. ORL thickness was higher in DR eyes than in noDR and healthy controls (HC), and RPE thickness was higher in noDR and DR eyes than in HC, with statistical significance for some sectors in noDR versus HC. No OCTA parameters of CC and Ch differed among groups, and no significant correlation was observed with auxological and metabolic parameters. In conclusion, ORL and RPE were both increased in adolescents with long-lasting T1D. Such changes were not associated with insulin dose and glycemia control, nor to any choroid or choriocapillaris flow change clinically detectable at OCTA, and they could be potential imaging biomarkers of disease progression.

Deep-learning-based automated measurement of outer retinal layer thickness for use in the assessment of age-related macular degeneration, applicable to both swept-source and spectral-domain OCT imaging.

Effective biomarkers are required for assessing the progression of age-related macular degeneration (AMD), a prevalent and progressive eye disease. This paper presents a deep learning-based automated algorithm, applicable to both swept-source OCT (SS-OCT) and spectral-domain OCT (SD-OCT) scans, for measuring outer retinal layer (ORL) thickness as a surrogate biomarker for outer retinal degeneration, e.g., photoreceptor disruption, to assess AMD progression. The algorithm was developed based on a modified TransUNet model with clinically annotated retinal features manifested in the progression of AMD. The algorithm demonstrates a high accuracy with an intersection of union (IoU) of 0.9698 in the testing dataset for segmenting ORL using both SS-OCT and SD-OCT datasets. The robustness and applicability of the algorithm are indicated by strong correlation (r = 0.9551, P < 0.0001 in the central-fovea 3 mm-circle, and r = 0.9442, P < 0.0001 in the 5 mm-circle) and agreement (the mean bias = 0.5440 um in the 3-mm circle, and 1.392 um in the 5-mm circle) of the ORL thickness measurements between SS-OCT and SD-OCT scans. Comparative analysis reveals significant differences (P < 0.0001) in ORL thickness among 80 normal eyes, 30 intermediate AMD eyes with reticular pseudodrusen, 49 intermediate AMD eyes with drusen, and 40 late AMD eyes with geographic atrophy, highlighting its potential as an independent biomarker for predicting AMD progression. The findings provide valuable insights into the ORL alterations associated with different stages of AMD and emphasize the potential of ORL thickness as a sensitive indicator of AMD severity and progression.

Relationships between mesopic visual sensitivity and macular inner and outer retinal layer thickness in healthy younger, middle-aged and older adults.

To examine relationships between mesopic visual sensitivity measurements on microperimetry and macular inner and outer retinal layer (IRL and ORL) thicknesses in healthy younger, middle-aged and older subjects. In total, 154 healthy adults were divided into three age groups each with similar mean sensitivity. Regional retinal sensitivity (determined by mesopic fundus-controlled microperimetry) and IRL (ganglion cell-related layer) and ORL thicknesses were measured in the five subfields: central fovea (1 mm diameter) and the quadrants temporal, nasal, superior and inferior of a parafoveal ring of outer diameter 3 mm and inner diameter 1 mm. Relationships between regional sensitivity and corresponding IRL and ORL thicknesses were assessed through a univariate and multivariate linear regression model. Visual sensitivity means for each subfield differed across age groups (all p < 0.001). In each parafoveal ring quadrant, mean IRL thickness was reduced in the older eyes compared to the other groups (all p < 0.0001). In the inferior region, worse sensitivity was correlated with greater IRL thickness (p = 0.0207) in the middle-aged group and with a thicker ORL (p < 0.0001) and thinner IRL (p = 0.0003) in the older eyes (R2 = 0.51). The slopes of regression lines relating sensitivity to IRL thickness and age group (p = 0.0027) or to ORL thickness and age group (p = 0.0020) differed significantly. The relationship observed between mesopic visual sensitivity and retinal layer thickness varied with age. A worse sensitivity was related to a thicker macular IRL layer in middle-aged eyes and to a thicker ORL and thinner IRL in older eyes.

Decreased Central Macular Choriocapillaris Perfusion Correlates With Increased Low Luminance Visual Acuity Deficits

Correlations between low luminance visual acuity deficits (LLVADs) and central choriocapillaris perfusion deficits were investigated to help explain how increases in LLVAD scores at baseline predict annual growth rates of geographic atrophy (GA). Prospective cross-sectional study. Photopic luminance best-corrected visual acuity (PL-BCVA) and low luminance BCVA (LL-BCVA) were measured using the Early Treatment Diabetic Retinopathy Study chart. LL-BCVA was measured using a 2.0-log unit neutral density filter. LLVADs were calculated as the difference between PL-BCVA and LL-BCVA. Within a fovea-centered 1-mm circle, the percentage of choriocapillaris flow deficits (CC FD%), drusen volume, optical attenuation coefficient (OAC) elevation volume, and outer retinal layer (ORL) thickness were assessed. In all 90 eyes (30 normal eyes; 31 drusen-only eyes; 29 non-foveal GA eyes), significant correlations were found between the central CC FD% and PL-BCVA (r=-0.393, P < .001), LL-BCVA (r=-0.534, P < .001), and the LLVAD (r=0.439, P < .001). Central cube root (cubrt) drusen volume, cubrt OAC elevation volume, and ORL thickness were correlated with PL-BCVA, LL-BCVA, and LLVADs (all P < .05). Stepwise regression models showed that central cubrt OAC elevation volume and ORL thickness were associated with PL-BCVA (R2=0.24, P < .05); central CC FD%, cubrt OAC elevation volume, and ORL thickness were associated with LL-BCVA (R2=0.44, P < .01); and central CC FD% and ORL thickness were associated with LLVAD (R2=0.24, P < .01). The significant correlations between central CC FD% and LLVAD support the hypothesis that the ability of LLVAD to predict the growth of GA is mediated through a decrease in macular choriocapillaris perfusion.

Decreased Macular Choriocapillaris Perfusion in Eyes With Macular Reticular Pseudodrusen Imaged With Swept-Source OCT Angiography.

To determine if macular reticular pseudodrusen (RPD) were associated with markers of impaired macular choroidal perfusion, we investigated measurements of macular choriocapillaris (CC) flow deficits (FDs), CC thickness, and mean choroidal thickness (MCT) in eyes with macular RPD compared with normal eyes and eyes with soft drusen. Eyes with intermediate age-related macular degeneration (iAMD) and normal eyes underwent 6 × 6 mm swept-source optical coherence tomography angiography (SS-OCTA) imaging to diagnose macular RPD, occupying over 25% of the fovea-centered 5 mm diameter circle, and measure outer retinal layer (ORL) thickness, CC FDs, CC thickness, MCT, and choroidal vascularity index (CVI) using previously published strategies within the same fovea-centered 5 mm circle. Ninety eyes were included; 30 normal eyes, 30 eyes with soft drusen, and 30 eyes with macular RPD. The RPD eyes showed higher macular CC FDs than normal eyes (P < 0.001) and soft drusen eyes (P = 0.019). Macular CC thickness was decreased in RPD eyes compared with normal eyes (P < 0.001) and soft drusen eyes (P = 0.016). Macular MCT in RPD eyes was thinner than normal eyes (P = 0.005) and soft drusen eyes (P < 0.001). No statistically and clinically significant differences were found in the ORL thickness and CVI measurements between RPD eyes and the other two groups (all P > 0.05). Eyes with macular RPD had decreased macular CC perfusion, decreased CC thickness, and decreased MCT measurements compared with normal and soft drusen eyes, suggesting that RPD may result from impaired choroidal perfusion.

Rod and Cone Dark Adaptation in Congenital Aniridia and Its Association With Retinal Structure.

To characterize the association between dark-adapted rod and cone sensitivity and retinal structure in PAX6-related aniridia. Dark-adaptation curves were measured after a 5-minute exposure to bright light with red (625 nm) and green (527 nm) 2° circular light stimuli presented at ≈20° temporal retinal eccentricity in 27 participants with aniridia (nine males; 11-66 years old) and 38 age-matched healthy controls. A two-stage exponential model was fitted to each participant's responses to determine their cone and rod thresholds over time. The thicknesses of macular inner and outer retinal layers were obtained from optical coherence tomography images in 20 patients with aniridia and the 38 healthy controls. Aniridia-associated keratopathy (AAK) grade (0-3) and lens opacities were quantified by clinical examination of the anterior segment. The rod-cone break time was similar between patients with aniridia and healthy controls. Dark-adapted cone and the rod thresholds were higher in aniridia compared with healthy controls. In aniridia, foveal outer retinal layer thickness correlated with both final cone and rod thresholds. A multiple regression model indicated that foveal outer retinal layer thickness and age were the main explanatory variables to predict both final cone and rod thresholds in aniridia when the AAK grade was 2 or less. The results show that both rod- and cone-related functions are affected in PAX6-related aniridia and suggest that retinal anatomical and physiological changes extend beyond the area commonly studied in this condition: the central macula.

Quantitative Analysis of Inner, Middle, and Outer Retinal Thickness by Optical Coherence Tomography in Children and Adolescents.

To describe the variance of inner, middle, and outer retinal layer thicknesses (IRT, MRT, and ORT) at the macular area in children and adolescents with normal eyes in different age groups. This cross-sectional study enrolled subjects aged 5-18 years with normal eyes. The macula was scanned by optical coherence tomography (6 mm × 6 mm AngioScan-Optovue). Four age groups were defined (≤7, 7-10, 11-14, and ≥14 years). The influences of age and gender were analyzed. One hundred and thirty-nine eyes of 69 subjects with a mean age of 10.92 ± 3.51 years were registered. The mean whole macular thickness (MT) was 297.32 ± 11.05 in males and 303.197 ± 13.32 in females (P = 0.01, t-test). The MT in each aging group was 301.47 ± 2.5, 295.53 ± 1.71, 300.81 ± 2.12, and 298.6 ± 1.87, subsequently (P = 0.17, analysis of variance test). Significant differences were found between the sexes at the perifoveal area and mainly in IRT. No correlation between eyes was noted. We observed that the RT fluctuates during growth and that gender has some influence on the evolution of RT. IRT and MRT changed reciprocally in all macular areas, whereas ORT expanded in all age groups of children and adolescents. No subsegmental retinal thickness difference between eyes was observed in pediatric groups in this study, while gender had some influence on perifoveal IRT. Despite the fact that this study is not a longitudinal study, we can get some insight into the developmental changes in retinal thickness and its clinical applications in children and adolescents.

Predictors for metamorphopsia in eyes undergoing macular hole surgery

Metamorphopsia is an important visual symptom of macular disease. We determined predictors for metamorphopsia investigating the relationships of macular hole (MH) diameter and retinal layer thicknesses with metamorphopsia after MH surgery. Forty-two eyes of 42 consecutive patients undergoing MH surgery were retrospectively studied. Metamorphopsia was measured with M-CHARTS. Inner nuclear layer (INL) and outer retinal layer (OR) thicknesses were measured 1000 μm away from central fovea at using Spectralis. Preoperative M-CHARTS scores correlated with MH diameters (P = 0.007–0.031) and changes of temporal OR thickness (P = 0.008–0.010). Postoperative M-CHARTS score at 3 months correlated with preoperative nasal and inferior OR thicknesses (P = 0.003 and 0.016) and with changes of superior INL at 3 and 6 months (P = 0.011 and 0.025), and score at 1 month with change of temporal OR at 6 months (P = 0.033). Postoperative improvement of M-CHARTS scores correlated with changes of temporal INL and superior OR (P = 0.026 and 0.002). Multiple regression analysis revealed that MH diameter was a significant predictor for metamorphopsia. Photoreceptor displacement and inner retinal change may generate metamorphopsia in MH undergoing surgery, however MH diameter is the most powerful predictor.

Reproducibility of each retinal layer thickness measurement in epiretinal membrane patients with ectopic inner foveal layers

BackgroundTo identify the reliability of each retinal layer thickness measurement in epiretinal membrane (ERM) patients with ectopic inner foveal layers (EIFLs).MethodsSubjects were divided into two groups: ERM patients with EIFLs (Group 1) and without EIFLs (Group 2). The retinal layer thickness was measured twice, and intraclass correlation coefficient (ICC) and coefficient of variation (CV) values were calculated.ResultsIn Group 1, the CVs of the nerve fiber layer (NFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), and outer nuclear layer (ONL) were 22.39%, 13.12%, 13.37%, 13.21%, 15.09%, and 11.94%, while the ICCs were 0.431, 0.550, 0.440, 0.286, 0.279, and 0.503, respectively. In Group 2, the CVs were 18.20%, 10.59%, 10.65%, 13.27%, 14.75%, and 10.37%, while the ICCs were 0.788, 0.834, 0.830, 0.715, 0.226, and 0.439, respectively. The average central macular thickness (CMT) was significantly correlated with the CVs of NFL (coefficient = 0.317; P < 0.001), GCL (coefficient = 0.328; P < 0.001), and IPL (coefficient = 0.186; P = 0.042) in Group 1.ConclusionsThe reproducibility of the inner retinal layer thickness measurements in ERM patients with EIFLs was low compared to those without EIFLs. The reproducibility of the outer retinal layer thickness measurements, including OPL and ONL, was poor regardless of the presence of EIFLs in ERM patients. Additionally, the thicker the CMT in patients with EIFLs, the lower the reproducibility of the inner retinal layer thickness measurements.

Characteristics and significance of outer retinal thickness changes in reticular macular disease

Objective: To study the characteristics and significance of changes in the thickness of the outer retinal layer (ORL) outside the macula in patients with reticular macular disease (RMD). Methods: A cross-sectional study was conducted. The clinical data of patients who visited the Department of Ophthalmology of the First Affiliated Hospital of Guangzhou Medical University from February to September 2019 were retrospectively collected. Thirty-one patients with at least one eye (54 eyes in total) diagnosed with early/mid-stage age-related macular degeneration (AMD) were consecutively included in the AMD group, and 33 patients with at least one eye (64 eyes in total) showing subretinal wart-like deposits on optical coherence tomography images were consecutively included in the RMD group. Thirty-two volunteers aged between 50 to 90 years with a normal fundus in both eyes (64 eyes in total) were consecutively included in the healthy control (HC) group. Frequency domain optical coherence tomography was applied to examine and analyze the thickness features of the ORL, inner retinal layer and choroid at the macular fovea (F), 2 mm of the temporal edge (T), the nasal edge (N), the superior edge (S) and inferior edge (I) of the macular fovea in each group. The correlations of the thickness of ORL with the choroidal thickness and the blood flow density of the choriocapillaris layer in patients with RMD were also analyzed. Results: The thickness of ORL at the F, T, S and I sites in the RMD group was significantly thinner than that in the AMD and HC groups. The difference was most obvious at the F site [(90.27±8.93), (98.04±11.7) and (97.19±7.02)μm] in the RMD, AMD and HC groups, respectively; all P<0.01). In the logistic regression model with independent variables of the ORL thickness at the macular F site, gender and age, there was a significant association between the thickness of ORL at the F site and the incidence of RMD (odds ratio=0.926, P<0.05). The ORL and choroid in the eyes of patients with RMD were significantly thinner at the F site [(90.27±8.93) and (163.21±72.43) μm, respectively; both P<0.01] compared with the AMD [(98.04±11.7) and (235.34±64.15) μm, respectively] and HC [(97.19±7.02) and (240.08±62.27) μm, respectively] groups. However, the ORL and choroidal thickness did not show significant and strong linear correlations at multiple sites. In contrast, there was a significant linear correlation between the blood flow density of the choriocapillaris layer and the thickness of ORL at the F, T and S sites in patients with RMD (r=0.487, 0.722, 0.467, respectively; all P<0.05). Conclusions: The thickness of ORL outside the macula of eyes with RMD is thinner than that of healthy eyes and eyes with early/mid-stage AMD. The thinning of ORL outside the macula is related to the decrease in the blood flow density of the choriocapillaris layer in patients with RMD.

The relationships between mesopic light sensitivity and macular inner and outer retinal layer thicknesses in older healthy adults

AbstractPurpose: Structural and functional markers are important for the early detection of neurodegenerative diseases of the eye. This study investigates the relationships between macular layer thicknesses and mesopic light sensitivity (MLS) in older healthy eyes.Methods: Measurements were made in 38 eyes of 38 healthy individuals of mean age 67 ± 5.6 years (range 60–80 years) and good visual acuity. MLS was measured with macular integrity assessment (MAIA) microperimetry at the central 10° diameter circle. MLSs at the central subfield (1° radius) and at four regions (temporal, nasal, superior, inferior) of the parafoveal ring (3°–5° radius of eccentricity) were registered. Total, inner, and outer retinal layer (IRL and ORL) thicknesses were measured in the macular region through spectral‐domain optical coherence tomography (SD‐OCT). Relationships between MLS and the retinal thickness in the corresponding macular region were examined using forward stepwise multiple linear regression analyses.Results: ORL and IRL thickness in the inferior parafoveal ring were significant contributing factors to the inferior MLS (ORL: p &lt; 0.0001; IRL: p = 0.0003; R2 model = 51%). Increased ORL thickness and decreased IRL thickness correlated with worse MLS. The total retinal thickness, age, sex, refractive error, axial length, retinal illuminance or visual acuity variables were not found to be significant predictors of MLS.Conclusions: ORL and IRL thicknesses predict inferior parafoveal MLS in healthy older eyes. The measurement of MLS in combination with macular layer thicknesses may be useful for detecting loss of sensitivity caused by early degenerative diseases of the retina.

Inner retinal layers' thickness changes in relation to age in healthy eyes

AbstractPurpose: Characterizing the structural change of the macula produced by aging in healthy eyes is essential to discriminate physiological alterations typical of aging from other pathological signs. In this study, macular thicknesses measured by spectral‐domain optical coherence tomography (SD‐OCT) were characterized in young, middle‐aged, and older subjects without ocular pathology.Methods: The study design was observational cross‐sectional and was conducted in 154 eyes of 154 healthy participants between 20 and 80 years (mean 44 ± 18 years of age) divided into three age groups: young (20–39), middle‐aged (40–59) and older (60–80). Macular thicknesses were measured through SD‐OCT using the grid employed of the Early Treatment Diagnostic Retinopathy Study (ETDRS). We analysed five sub‐fields: the central fovea and the four regions (temporal, nasal, superior, inferior) of the parafoveal ring. Mean macular thicknesses were recorded for each of the three retinal segmentations: the inner retinal layer (IRL), the outer retinal layer (ORL) and the total retinal layer. Comparisons of macular thicknesses across age groups were performed.Results: Mean total and ORL thicknesses were not significantly different in the central subfield and each region of the parafoveal ring of the ETDRS grid (temporal, nasal, nasal, inferior and overall) for the three age groups. However, age had a significant effect on IRL thickness in each region of the parafoveal ring. In the superior, nasal and inferior regions, mean IRL thicknesses decreased significantly in the older age group compared to the other age groups (all p &lt; 0.0001). In the temporal region, mean IRL thickness decreased with age and was significantly different for each of the three age groups (p &lt; 0.0001).Conclusions: Age did not significantly influence total and ORL thicknesses in the macula. However, the macular thickness of the IRL decreased in subjects older than 60 years of age.

Speckle Contrast as Retinal Tissue Integrity Biomarker in Patients with Type 1 Diabetes Mellitus with No Retinopathy

To study the retinal and choroidal layers in type 1 diabetes mellitus (DM1) without diabetic retinopathy (DR), using speckle contrast of optical coherence tomography (OCT) images as a tissue biomarker in comparison with healthy subjects. OCT Spectralis images of 148 eyes, 84 from DM1 patients without DR signs, and 64 belonging to the control group, were collected. The speckle contrast and thickness of the inner retinal layer (IRL), the outer retinal layer (ORL), and the choroidal layer in the nasal parafoveal area (N3), were prospectively analyzed. A statistically significant difference (p = 0.001) in the IRL thickness between groups was observed, being thicker in the DM1 group. There were no differences in the ORL and choroidal thicknesses between groups. A statistically significant difference (p = 0.02) in the IRL speckle contrast was obtained, being lower in the DM1 group. The maximum speckle contrast was reached in the ORL for both groups, although in the DM1 group, it occurs closer to the choroid, at 64 ± 8 μm (p = 0.008). Statistically significant differences were found in speckle contrast and thickness between the control and the DM1 group, suggesting an IRL alteration of DM1 patients, supporting the retinal neurodegeneration before DR signs are observed.

Does the Outer Retinal Thickness Around Geographic Atrophy Represent Another Clinical Biomarker for Predicting Growth?

To determine whether the outer retinal layer (ORL) thickness around geographic atrophy (GA) could serve as a clinical biomarker to predict the annual enlargement rate (ER) of GA. Retrospective analysis of a prospective, observational case series. Eyes with GA were imaged with a swept-source OCT 6×6 mm scan pattern. GA lesions were measured from customized en face OCT images and the annual ERs were calculated. The ORL was defined and segmented from the inner boundary of outer plexiform layer (OPL) to the inner boundary of retinal pigment epithelium (RPE) layer. The ORL thickness was measured at different subregions around GA. A total of 38 eyes from 27 participants were included. The same eyes were used for the choriocapillaris (CC) flow deficit (FD) analysis and the RPE to the Bruch membrane (RPE-BM) distance measurements. A negative correlation was observed between the ORL thickness and the GA growth. The ORL thickness in a 300-μm rim around GA showed the strongest correlation with the GA growth (r=-0.457, P=.004). No correlations were found between the ORL thickness and the CC FDs; however, a significant correlation was found between the ORL thickness and the RPE-BM distances around GA (r=-0.398, P=.013). ORL thickness showed a significant negative correlation with annual GA growth, but also showed a significant correlation with the RPE-BM distances, suggesting that they were dependently correlated with GA growth. This finding suggests that the loss of photoreceptors was associated with the formation of basal laminar deposits around GA.

Tight adherent feature on optical coherence tomography predict postoperative visual outcome in epiretinal membrane eyes

BackgroundTo identify the predictive parameter among preoperative measurements that best predicts postoperative visual outcome in the epiretinal membrane (ERM).MethodsThirty-three consecutive patients with idiopathic unilateral ERM patients between 2015 and 2018 were enrolled. Nineteen healthy normal eyes were selected as an independent age-matched group. Based on preoperative optical coherence tomography (OCT), we further divided the patients with ERM into two groups: type 1, loosely attached ERM, and type 2, tight adherent ERM. We documented the vision and thickness of various retinal layers: nerve fiber layer, ganglion cell layer, inner plexiform layer (GCL + IPL), inner nuclear layer (INL), outer retinal layer (ORL), and retinal pigment epithelium/Bruch complex layer before and after the surgery. The association between postoperative visual acuity and these variables was analyzed using multiple linear regression analysis.ResultsAll retinal layers of ERM eyes were thicker than the normal eyes (P < 0.05). Among ERMs, we identified 11 eyes with type 1 adhesions and 22 eyes with type 2 adhesions. The preoperative GCL + IPL layers were significantly thicker in type 2 patients than in type 1 patients (93.67 ± 33.03 um vs 167.71 ± 13.77 um; P = 0.023). Greater GCL + IPL thickness was correlated with a worse postoperative visual acuity and multiple linear regression analysis showed that GCL + IPL thickness was an independent predictor of postoperative visual acuity (VA) (beta value = 0.689; P = 0.012). A greater thickness of GCL + IPL layers of type 2 patients had worse postoperative best-corrected visual acuity (BCVA) (P = 0.028). Ectopic inner foveal layers with disappearance of fovea pit were persistently presented in OCT profiles of both groups.ConclusionIdiopathic ERM demonstrated significantly thicker inner retinal layers (GCL + IPL and INL). However, the ORL thickness was similar between the normal eyes and ERM eyes. The preoperative GCL + IPL layers were significantly thicker in patients with type 2 ERM than that in patients with type 1 ERM. The increase in GCL + IPL thickness was significantly correlated with worse postoperative visual outcomes.