Retinal Pigment Epithelium Thickness Research Articles

The thickness and volume of the choroid, outer retinal layers and retinal pigment epithelium layer changes in patients with diabetic retinopathy.

To evaluate the thickness and volume changes of the choroidal, outer retinal layers (ORL) and retinal pigment epithelium (RPE) in patients with diabetic retinopathy (DR) using optical coherence tomography (OCT) and correlate them with visual acuity. We carried out a retrospective observational case series. Consecutive DR patients were recruited for color fundus photography and OCT assessment. The RPE, ORL and choroidal thickness were measured. The correlation with the best-corrected visual acuity (BCVA) was also investigated. The study included 128 eyes, comprising 45 eyes of 25 diabetic macular edema (DME) patients, 34 eyes of 20 DR without DME (non-DME) patients, and 49 eyes of 25 age-matched normal individuals. The choroidal thickness in DR patients were decreased statistically significantly compared with the control group (P<0.05). The mean macular ORL thickness in DME (73.02±15.34 µm) and non-DME groups (76.35±7.32 µm) were decreased statistically significantly compared with the control group (80.20±5.85 µm; P=0.006, P=0.013, respectively). In both the non-DME and DME groups, the RPE thickness were decreased compared with the control group (P<0.05), except in the macular and central ring. The BCVA were significant interactions with the total inner retinal volume and macular RPE thickness in the DME group (r=0.115, P<0.001, r=-0.013, P=0.017, respectively). The choroid, ORL and RPE thickness are significantly decreased in DR patients compared with controls in different segments.

Long-term follow-up of pachychoroid pigment epitheliopathy and lesion characteristics.

To investigate conversion of pachychoroid pigment epitheliopathy (PPE) lesions and the development of other pachychoroid spectrum diseases in patients with PPE during follow-up. We retrospectively reviewed medical records of 46 eyes of 44 patients who had a diagnosis of PPE and were followed up for at least 3years. Eyes with PPE (17.4%) developed central serous chorioretinopathy (CSC), and none developed pachychoroid neovasculopathy or polypoidal choroidal vasculopathy. Of 74 initial PPE lesions, 21.6% were retinal pigment epithelium (RPE) thickening, 36.5% were pigment epithelium detachment (PED), and 41.9% were RPE elevation with microbreak appearance (REwM). Five (62.5%) of the eight initial PPE lesions progressing to CSC were REwM. Two developed directly from the REwM and three REwMs transformed to PED first, and then progressed to CSC. Three initial PEDs progressed to CSC. REwMs can also transform to PED and RPE thickening. No initial PEDs or RPE thickenings transformed to a REwM. Of the new PPE lesions, 60% were REwM, 26.7% were PEDs, and 13.3% were RPE thickening. The smallest PPE lesion that can be detected is a REwM of RPE. It may be the precursor lesion for pachychoroid spectrum disease, but further large-scale prospective studies are required.

ELLIPSOID ZONE MAPPING AND OUTER RETINAL ASSESSMENT IN STARGARDT DISEASE.

To quantify and correlate ellipsoid zone and photoreceptor outer segment changes with visual acuity in Stargardt disease. An institutional review board-approved study of 32 eyes with Stargardt disease was performed. After spectral domain optical coherence tomography, the macular cube was exported into a novel analysis tool and volumetric assessment from the ellipsoid zone to the retinal pigment epithelium was performed. Using this information, mapping was completed with en face representation of the height between the ellipsoid zone and retinal pigment epithelium. This analysis provided quantification of ellipsoid zone and photoreceptor outer segments, including atrophy (ellipsoid zone to retinal pigment epithelium thickness = 0 μm) and attenuation (ellipsoid zone to retinal pigment epithelium thickness <20 μm). These parameters were compared with visual acuity and controls (n = 12 eyes). Visual acuity ranged from 20/30 to 20/250. The central foveal B-scan area of ellipsoid and photoreceptor outer segments was significantly less than controls (0.13 ± 0.05 mm vs. 0.17 ± 0.03 mm, respectively, P = 0.0074). The central foveal B-scan mean thickness measured 22.52 ± 9.0 μm in Stargardt versus 30.0 ± 5.08 μm (P = 0.0096). Atrophy and attenuation were significantly higher in Stargardt patients (22% vs. 1%, P = 0.005 and 43% vs. 1%, P = 0.0002). Visual acuity directly correlated with ellipsoid zone/outer segment volume (R = 0.57, P < 0.005) and inversely correlated with attenuation and atrophy (R = -0.53 and -0.57; P < 0.005 for all). Eyes with Stargardt disease frequently have significant disruption of the ellipsoid zone and outer segments. This degenerative change was successfully quantified with a novel assessment platform and identified correlates with visual function. This software provides the opportunity for quantitative assessment and possible longitudinal surveillance.

Multimodal imaging of combined harmatoma of the retina and retinal pigment epithelium

PurposeTo describe the use of multimodal imaging in defining the anatomical features of combined harmatoma of the retina and retinal pigment epithelium (CHRRPE) and assess its role in the diagnosis and management of CHRRPE.MethodsRetrospective case series of three patients with unilateral, juxta‐papillary CHRRPE, who underwent Spectralis Enhanced Depth Imaging Optical Coherence Tomography (EDI‐OCT), MultiColor (MC) and autofluorescence (AF) in addition to a complete ophthalmic examination.ResultsEDI‐OCT demonstrated thickening and disorganisation of retinal architecture, with intraretinal cysts disrupting the retinal layers and a loss of photoreceptors. An overlying epiretinal membrane was shown to be causing ‘mini‐peaks’ of the inner retinal surface in all cases and vitreoretinal traction in two cases. Details of the retinal pigment epithelium (RPE) were revealed, including RPE thickening and sectoral atrophy. MC revealed areas of red‐shifting, demonstrating partial pigmentation. On green reflectance (GR) the degree of inner retinal distortion and extent of macular involvement could be visualised. Near infra‐red (NIRR) reflectance displayed the lesions as areas of hyporeflectance and allowed delineation of the tumour borders. On AF, the lesions were represented by areas of hypo‐autofluorescence that obscured the normal blood vessel hypo‐autofluorescence.ConclusionsIn this case series, multimodal imaging enabled the anatomical characteristics of CHRRPE to be defined in greater detail. NIRR enabled better visualisation of tumour boundaries and the extent of macular involvement, which may be useful in assessing the impact on visual function. GR better defined the degree of inner retinal distortion, which may be useful in surgical management decisions. We believe that multimodal imaging is a valuable adjunct in correctly diagnosing and managing CHRRPE.

Optical Coherence Tomography Features Preceding the Onset of Advanced Age-Related Macular Degeneration.

PurposeAge-related macular degeneration (AMD) is a progressive disease with multifactorial etiology. There is a need to identify clinical features that are harbingers of advanced disease. We evaluated morphologic features of the retina and choroid on optical coherence tomography (OCT) to determine if they predict progression to advanced disease.MethodsProgressors transitioned from early or intermediate AMD to advanced disease (n = 40 eyes), and were matched on baseline AMD grade and follow-up interval to nonprogressors who did not develop advanced AMD (n = 40 eyes). Features of the neurosensory retina, photoreceptors, retinal pigment epithelium (RPE), and choroid were evaluated. Logistic regression was used to evaluate univariate associations between features and progression to overall advanced AMD, geographic atrophy (GA), and neovascular disease (NV). Multivariate associations based on stepwise regression models were also assessed.ResultsEllipsoid zone disruption was associated with progression to overall advanced AMD and NV (odds ratios [ORs]: 17.9 and 30.6; P < 0.001), with a similar trend observed for GA. Drusenoid RPE detachment, RPE thickening, and retinal pigmentary hyperreflective material were significantly associated with higher risk of progression to advanced AMD (ORs: 5.0–8.5) and NV (ORs: 10.8–17.2). Pigmentary hyperreflective material was associated with progression to GA (OR: 7.5, P = 0.009). Total retinal thickness, pigmentary hyperreflective material, nascent GA features, and choroidal vessel abnormalities were independently associated with progression to advanced AMD in a multivariate stepwise model.ConclusionsAbnormalities in the photoreceptors, retinal thickness, RPE, and choroid were associated with higher risk of developing advanced AMD. These findings provide insights into disease progression, and may be helpful to identify earlier endpoints for clinical studies.

Retinal pigment epithelial features indicative of neovascular progression in age-related macular degeneration

Background/aimsTo identify characteristic retinal pigment epithelium (RPE) changes in fellow eyes of patients with neovascular age-related macular degeneration (nAMD) using polarisation-sensitive optical coherence tomography (PS-OCT).MethodsThirty-one fellow eyes of 31 patients...

Long-term Characterization of Retinal Degeneration in Royal College of Surgeons Rats Using Spectral-Domain Optical Coherence Tomography.

PurposeProspective treatments for age-related macular degeneration and inherited retinal degenerations are commonly evaluated in the Royal College of Surgeons (RCS) rat before translation into clinical application. Historically, retinal thickness obtained through postmortem anatomic assessments has been a key outcome measure; however, utility of this measurement is limited because it precludes the ability to perform longitudinal studies. To overcome this limitation, the present study was designed to provide a baseline longitudinal quantification of retinal thickness in the RCS rat by using spectral-domain optical coherence tomography (SD-OCT).MethodsHorizontal and vertical linear SD-OCT scans centered on the optic nerve were captured from Long-Evans control rats at P30, P60, P90 and from RCS rats between P17 and P90. Total retina (TR), outer nuclear layer+ (ONL+), inner nuclear layer (INL), and retinal pigment epithelium (RPE) thicknesses were quantified. Histologic sections of RCS retina obtained from P21 to P60 were compared to SD-OCT images.ResultsIn RCS rats, TR and ONL+ thickness decreased significantly as compared to Long-Evans controls. Changes in INL and RPE thickness were not significantly different between control and RCS retinas. From P30 to P90 a subretinal hyperreflective layer (HRL) was observed and quantified in RCS rats. After correlation with histology, the HRL was identified as disorganized outer segments and the location of accumulated debris.ConclusionsRetinal layer thickness can be quantified longitudinally throughout the course of retinal degeneration in the RCS rat by using SD-OCT. Thickness measurements obtained with SD-OCT were consistent with previous anatomic thickness assessments. This study provides baseline data for future longitudinal assessment of therapeutic agents in the RCS rat.

Changes in Macular Retinal Layers and Peripapillary Nerve Fiber Layer Thickness after 577-nm Pattern Scanning Laser in Patients with Diabetic Retinopathy.

PurposeThe aim of this study was to evaluate the changes in thickness of each macular retinal layer, the peripapillary retinal nerve fiber layer (RNFL), and central macular thickness (CMT) after 577-nm pattern scanning laser (PASCAL) photocoagulation in patients with diabetic retinopathy.MethodsThis retrospective study included 33 eyes with diabetic retinopathy that underwent 577-nm PASCAL photocoagulation. Each retinal layer thickness, peripapillary RNFL thickness, and CMT were measured by spectral-domain optical coherence tomography before 577-nm PASCAL photocoagulation, as well as at 1, 6, and 12 months after 577-nm PASCAL photocoagulation. Computerized intraretinal segmentation of optical coherence tomography was performed to identify the thickness of each retinal layer.ResultsThe average thickness of the RNFL, ganglion cell layer, inner plexiform layer, inner nuclear layer, inner retinal layer, and CMT at each follow-up increased significantly from baseline (p < 0.001), whereas that of the retinal pigment epithelium at each follow-up decreased significantly from baseline (p < 0.001). The average thickness of the peripapillary RNFL increased significantly at one month (p < 0.001). This thickness subsequently recovered to 7.48 µm, and there were no significant changes at six or 12 months compared to baseline (p > 0.05).ConclusionsEach macular retinal layer and CMT had a tendency to increase for one year after 577-nm PASCAL photocoagulation, whereas the average thickness of retinal pigment epithelium decreased at one-year follow-up compared to the baseline. Although an increase in peripapillary RNFL thickness was observed one month after 577-nm PASCAL photocoagulation, there were no significant changes at the one-year follow-up compared to the baseline.

VISUALIZING RETINAL PIGMENT EPITHELIUM PHENOTYPES IN THE TRANSITION TO ATROPHY IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION.

To enable future studies of retinal pigment epithelium (RPE) fate in the macular atrophy occurring in eyes with neovascular age-related macular degeneration (nvAMD), the authors determined how RPE morphology changes across the transition from health to atrophy in donor eyes with nvAMD. In RPE-Bruch membrane flat mounts of 5 nvAMD eyes, the terminations of organized RPE cytoskeleton and autofluorescent material were compared. In high-resolution histologic sections of 27 nvAMD eyes, RPE phenotypes were assessed at ±500 μm and ±100 μm from the descent of the external limiting membrane (ELM) toward the Bruch membrane. Thicknesses of RPE, basal laminar deposit (BLamD), and RPE + BLamD were determined. Shapes of the ELM descent were recorded. Approaching the ELM descent, the percentage of different RPE phenotypes and the thickness of RPE, BLamD, and RPE + BLamD each stayed roughly constant. Compared with a separately described cohort of eyes with geographic atrophy, eyes with nvAMD were more likely to have RPE dysmorphia that did not worsen toward the atrophy border, thinner BLamD overall (3.25 ± 3.46 μm vs. 7.99 ± 7.49 μm for geographic atrophy), and a higher proportion of oblique ELM descents (47.9 vs. 31.9%). The distribution of RPE phenotypes at the transition to macular atrophy in eyes with nvAMD differs from that in primary geographic atrophy, likely reflecting greater photoreceptor loss and the effects of exudation in nvAMD. This distribution, the shape of ELM descents, and thickness profiles may be useful metrics in clinical studies of macular atrophy using optical coherence tomography and fundus autofluorescence.

Associations with Retinal Pigment Epithelium Thickness Measures in a Large Cohort: Results from the UK Biobank

To describe associations of ocular and systemic factors with retinal pigment epithelium (RPE)-Bruch's membrane (BM) complex thickness as measured by spectral-domain (SD) optical coherence tomography (OCT). Multisite community-based study. This research has been conducted using the UK Biobank Resource. Sixty-seven thousand three hundred eighteen people 40 to 69 years old received questionnaires, physical examination, and eye examination, including macular SD OCT. Systematic selection process identified 34 652 eyes with high-quality SD OCT images from normal individuals for analysis. We included people with no self-reported ocular disease, diabetes, or neurologic disorders; visual acuity of ≥20/25; refraction between -6 diopters (D) to 6 D, and IOP of 6 to 21 mmHg. Only high-quality, well-centered SD OCT images with central, stable fixation were included. Descriptive statistics, t tests, and regression analyses were performed. Multivariate regression modeling was used to adjust for covariates and to identify relationships between RPE-BM thickness and ocular and systemic features. Retinal pigment epithelium-BM thickness, as measured by SD OCT segmentation using Topcon Advanced Boundary Segmentation at 9 Early Treatment of Diabetic Retinopathy Study subfields. Mean RPE-BM thickness was 26.3 μm (standard deviation, 4.8 μm) at central subfield. Multivariate regression with age stratification showed that RPE thinning became apparent after age 45. Among those aged ≤45, RPE-BM was significantly thicker among those of black or mixed/other race (+3.61 and+1.77 μm vs. white, respectively; P < 0.001) and higher hyperopia (+0.4 μm/D; P < 0.001), but not for other variables considered. Among those age >45, RPE-BM was significantly thinner with older age (-0.10 μm/year; P<0.001), Asian ethnicity (-0.45 μm vs. white; P= 0.02), taller height (-0.02 μm/cm; P < 0.001), higher IOP(-0.03 μm/mmHg; P < 0.001), and regular smoking (-0.27 μm vs. nonsmokers; P= 0.02). In contrast, RPE-BM was significantly thicker among black or mixed/other race (+3.29 μm and+0.81 μm vs. white, respectively; P < 0.001) and higher hyperopia (+0.28 μm/D; P < 0.001). There was no significant association with sex or Chinese ethnicity. We describe novel findings of RPE-BM thickness in normal individuals, a structure that varies with age, ethnicity, refraction, IOP, and smoking. The significant association with IOP is especially interesting and may have relevance for the etiology of glaucoma, while the association between age and smoking may have relevance for the etiology of age-related macular degeneration.

Tomographic analysis of the retinal layers in diabetic macular edema treated with dexamethasone intravitreal implant

PurposeTo study the morphological alterations in the individual retinal layers of patients with diabetic macular edema (DME) treated with dexamethasone intravitreal implant.MethodsRetrospective, observational study of patients with center‐involving DME treated with a single dexamethasone implant as primary or secondary treatment, and with at least two follow‐up visits. Central thickness of each retinal layer was obtained with optical coherence tomography automated segmentation (Heidelberg Spectralis Engineering, Germany), with manual correction as needed.ResultsTwenty one eyes of 18 type 2 diabetic patients were included (median HbA1c 7.1%). The median time of follow‐up after treatment was 8 weeks (visit 1) and 4 months (visit 2). At visit 1, a significant reduction in central macular thickness (CMT) (480 ± 24 to 325 ± 134), retinal nerve fibre layer (RNFL) (21 ± 1 to 18 ± 2), ganglion cell layer (GCL) (30 ± 2 to 22 ± 1), inner nuclear layer (94 ± 15 to 46 ± 6), outer plexiform layer (OPL) (35 ± 3 to 28 ± 1), outer nuclear layer (ONL) (176 ± 14 to 117 ± 18) and retinal pigment epithelium (RPE) (29 ± 7 to 15 ± 5) was noted (p &lt; 0.05 for all layers). At visit 2 there was a significant increase in CMT, (424 ± 270), although still lower than the baseline; there was also a significant increase in RNFL (25 ± 3), GCL (30 ± 3), OPL (40 ± 3), ONL (146 ± 20) and RPE (24 ± 5) (p &lt; 0.05). There was no difference in inner plexiform layer (IPL) or outer retinal layers thickness over time. Seven eyes had neurosensorial detachment (NSD) at baseline, versus 0 at visit 1 and 2 at visit 2.ConclusionsThe reduction in CMT noted in patients with diabetic macular edema treated with dexamethasone intravitreal implant is mostly due to resolution of NSD (which accounts to the automated RPE thickness) and the layers above external limiting membrane, except for IPL. This effect is highest at the first follow‐up visit.

Effect of aspirin on models of retinal pigment epithelium pathology.

To characterize the effect of aspirin (ASA) in mouse models of choroidal neovascularization (CNV) and retinal degeneration. In vivo: Male C57BL/6 mice were given ASA in food or regular rodent diet. CNV was induced by argon laser photocoagulation. Subretinal injections of polyethylene glycol 400 (PEG-400) were administered to induce retinal degeneration. CNV size, laser spot area and mean intensity of VEGF in the laser injured zones were measured. In the PEG injected eyes the thickness of retinal pigment epithelium (RPE) and choroid was measured. In vitro: Human ARPE-19 cells were treated with 0.5 or 2.0 mM/L of ASA for 72 h. ELISA was used to measure the concentration of VEGF and CCL-2 in the supernatants. Additionally, damaged RPE monolayer was treated with ASA (0.5 or 2.0 mM/L) and vehicle separately. Size of damaged area was measured. ELISA was used to measure secretion of VEGF-A and CCL-2 by damaged cells after 24 h. No statistically significant effect of ASA on CNV size, laser spot size or VEGF expression was noted in CNV model. In the PEG model, ASA did not have any effect on RPE and choroid thickness; however, a significant increase in RPE atrophy was observed (P = 0.02 + 38%). In addition, ASA had a significant effect on the ability of the RPE cells to regenerate and become confluent after mechanical damage. ASA at doses consumed clinically for various medical causes may not worsen CNV in human subjects. However, ASA may increase RPE atrophy when consumed over long periods of time.

Optical Coherence Tomography: An Adjunctive Tool for Differentiating between Choroidal Melanoma and Metastasis.

Purpose. To investigate the value of optical coherence tomography (OCT) for differentiation between choroidal melanoma and metastasis based on characteristics of the anterior choroidal surface and the chorioretinal interface. Methods. This retrospective observational case series included 29 patients with untreated choroidal melanomas and 21 patients with untreated choroidal metastases. Regularity and lobularity characteristics of the anterior choroidal surface were evaluated in a masked manner. Retinal and retinal pigment epithelium (RPE) findings were documented as well. Results. OCT demonstrated a regular and smooth anterior choroidal surface in 89.7% of the eyes with melanoma and in 47.6% of the eyes with metastasis (p = 0.002; sensitivity = 89.7%; specificity = 52.4%). The anterior choroidal contour was lobulated in 81.0% of the eyes with metastasis versus 17.2% of the eyes with melanoma (p < 0.001; sensitivity = 82.8%; specificity = 81.0%). RPE thickness and neuroretinal characteristics (e.g., retinal thickness, the presence of cysts, and the presence of subretinal fluid) were similar in both choroidal tumors. Conclusion. OCT may serve as a noninvasive adjunctive tool for the differential diagnosis of choroidal tumors. Choroidal melanomas usually demonstrate regular surfaces on OCT, while choroidal metastases usually have an irregular and lobulated surface.

Monte Carlo investigation on quantifying the retinal pigment epithelium melanin concentration by photoacoustic ophthalmoscopy.

The retinal pigment epithelium (RPE) melanin plays an important role in maintaining normal visual functions. A decrease in the RPE melanin concentration with aging is believed to be associated with several blinding diseases, including age-related macular degeneration. Quantifying the RPE melanin noninvasively is therefore important in evaluating the retinal health and aging conditions. Photoacoustic ophthalmoscopy (PAOM), as an optical absorption-based imaging technology, can potentially be applied to measure variations in the RPE melanin if the relationship between the detected photoacoustic (PA) signal amplitudes and the RPE melanin concentrations can be established. In this work, we tested the feasibility of using PA signals from retinal blood vessels as references to measure RPE melanin variation using Monte Carlo (MC) simulation. The influences from PAOM axial resolution, the depth and diameter of the retinal blood vessel, and the RPE thickness were examined. We proposed a calibration scheme by relating detected PA signals to the RPE melanin concentrations, and we found that the scheme is robust to these tested parameters. This study suggests that PAOM has the capability of quantitatively measuring the RPE melanin in vivo.

Spectral‐domain EDI‐OCT in small uveal melanoma and “pseudomelanomas”

PurposeTo reveal diagnostic symptoms of small uveal melanoma and “pseudomelanomas” by spectral‐domain EDI‐OCT.MethodsThe results of complex research (ophthalmoscopy, ultrasonography, spectral‐domain EDI‐OCT) of 230 patients (230 eyes) aged from 13 to 75 (mean 49 ± 1.1) years with diagnosis “small uveal melanoma” were analyzed.ResultsIn 142 (61.7%) from 230 cases small uveal melanoma was diagnosed. The tomographycal symptoms were retinal thickness caused by neuroepithelium detachment, cystoid retinal edema; bow‐shaped choroidal profile; retinal thickness in contiguous zone caused by neuroepithelium detachment. In 88 cases (38.3%) “pseudomelanomas” were diagnosed. In age‐related macular degeneration (38) retinal pigment epithelium detachment, hyperreflective focus (subretinal membrane), equal choroidal profile; in subretinal hemorrhage (25) equal elevation of choroidal profile without retinal fluid; in peripheral retinal degeneration (12) retinal thinning, insignificant elevation of choroidal profile, hyperreflective foci on RPE level; in congenital hypertrophy of retinal pigment epithelium (13) equal choroidal profile, retinal thinning, thickness of retinal pigment epithelium were diagnosed.ConclusionsThus, spectral‐domain EDI‐OCT allow to reveal small uveal melanoma and “pseudomelanomas” symptoms for adequate treatment.

Correlation between Retinal Changes and Visual Function in Late-Stage Vogt-Koyanagi-Harada Disease: An Optical Coherence Tomography Study.

Purpose. To characterize the optical coherence tomography (OCT) findings in late-stage Vogt-Koyanagi-Harada (VKH) disease and its correlation with visual function. Methods. The records of patients with late-stage VKH disease (defined as ≥12 months from disease onset) were retrospectively reviewed. The analysis focused on the OCT findings and microperimetry, in addition to the possible correlation between morphology and functional findings. Results. Twenty-nine patients (58 eyes) were included. Mean age at onset was 34.24 ± 10.67 years. The OCT revealed that the outer retina and retinal pigment epithelium (RPE) were mainly affected. These effects included RPE thickening and breakage or disappearance of the cone outer segment tip (COST) line and/or inner segment/outer segment (IS/OS) junction. The COST line and IS/OS results were related to macular function and the interval between symptom onset and initiation of high-dose corticosteroid treatment (all P < 0.01). Eyes with intact COST lines demonstrated intact IS/OS and normal RPE layers as well as better visual function and normal retinal sensitivity. Conclusions. The OCT findings are strongly correlated with macular function, as well as other clinical findings in late-stage VKH. With respect to the COST line and retinal sensitivity especially, the OCT and microperimetry findings may be useful for evaluating later-stage VKH.

ENHANCED DEPTH IMAGING OPTICAL COHERENCE TOMOGRAPHY OF CHOROIDAL METASTASIS

To evaluate the imaging features of choroidal metastasis using enhanced depth imaging optical coherence tomography (EDI-OCT). Enhanced depth imaging optical coherence tomography imaging features of 24 choroidal metastatic tumors with <2.5 mm of thickness on ultrasonography were retrospectively evaluated. Of the 24 tumors, 10 (42%) were located at the macula and 14 (58%) between the macula and equator. Tumor was plateau-shaped in 18 (75%) tumors and dome-shaped in 6 (25%) tumors. On EDI-OCT, choroidal metastasis showed low internal optical reflectivity in 17 (71%) tumors and high internal reflectivity in 7 (29%) tumors. Most common associated features were overlying choriocapillaris thinning in 24 (100%) tumors, shaggy or irregular, elongated photoreceptors in 18 (75%) tumors, subretinal fluid with high-reflective speckles in 16 (67%) tumors, and thickening of retinal pigment epithelium in 9 (37%) tumors. The mean tumor thickness was 854 μm (range, 287-1500 μm) on EDI-OCT and 2064 μm (range, 0-2400 μm) on ultrasonography. After treatment, the mean decrease in tumor thickness was 520 μm (range, 134-917 μm) on EDI-OCT and 714 μm (range, 0-1500 μm) on ultrasonography. Internal optical reflectivity changed from low to high in five tumors. Choriocapillaris thinning and shaggy photoreceptors improved in four and five tumors, respectively. Subretinal fluid resolved in four tumors. On EDI-OCT, choroidal metastasis showed overlying choriocapillaris thinning, plateau-shaped tumor, shaggy photoreceptors, and subretinal fluid with high-reflective speckles in more than half of the tumors. Enhanced depth imaging optical coherence tomography was more sensitive than ultrasonography in the evaluation of small metastatic tumors at presentation and after treatment.

Relationship between Retinal Microstructures on Optical Coherence Tomography and Microperimetry in Age-Related Macular Degeneration

To determine the relationship between structural parameters of the outer retina on spectral-domain optical coherence tomography (SD-OCT) and microperimetric retinal sensitivity in early stages of age-related macular degeneration (AMD). Prospective, observational study. Seventy-five eyes of 75 participants with early stages of AMD (drusen ≥ 125 μm, with/without pigmentary abnormalities) and 25 control participants of a similar age. Participants underwent microperimetry testing and high-resolution SD-OCT scans. Structural parameters at 5 central points (0°, 1°, and 2.33° nasal and temporal to the fovea along the horizontal axis) corresponding to areas tested by microperimetry were compared. Structural parameters included outer segment (OS) length, thickness and elevation of the retinal pigment epithelium (RPE) band, grading of the inner-segment ellipsoid (ISe) band integrity, and presence of hyperreflective foci (HF). Relationship between structural parameters and retinal sensitivity. Retinal sensitivity was significantly correlated with RPE elevation (P<0.001), ISe grading (P<0.001), and presence of HF (P ≤ 0.018) at all test points, but not with OS length (P ≥ 0.093) or RPE thickness (P ≥ 0.125). However, multiple linear regression analyses revealed that only ISe grading (P ≤ 0.011) and RPE elevation (P ≤ 0.030) remained significantly associated with retinal sensitivity at all points. By using a simple linear model incorporating ISe grading and RPE elevation to predict values of retinal sensitivity, the 95% limits of agreement between the predicted and the actual value was ± 3.83 dB. The integrity of the ISe band and drusen-associated RPE elevation are significant independent predictors of microperimetric retinal sensitivity. Our findings imply that these 2 structural parameters may be surrogate markers of retinal function in the early stages of AMD.

Analysis of macular choroidal and retinal pigment epithelium thickness in tilted disc syndrome

Objective To observe the macular choroidal and retinal pigment epithelium (RPE) thickness in tilted disc syndrome (TDS).Methods This is a descriptive study.Thirty eyes of 22 TDS patients (TDS group) and 30 eyes of 15 normal subjects (control group) were analyzed.Among TDS group,there were 8 males (11 eyes) and 14 females (19 eyes),the average age was (9.00±2.78) years old.The best corrected visual acuity (BCVA) was 0.3-1.0,and the average spherical equivalent degree was (-3.44±2.22) DS.Among the control group,there were 8 males (16 eyes) and 7 females (14 eyes),the average age was (9.33±1.11) years old.The best corrected visual acuity (BCVA) ≥1.0,and the average spherical equivalent degree was (-3.18 ± 1.13)DS.The difference of the spherical equivalent degree between two groups was not statistically significant (t=-1.648,P=0.110).Enhanced depth imaging techniques of frequency-domain optical coherence tomography was used to measure the thickness of choroid and RPE at totally 17 sites.There sites included subfoveal,4 sites each (500,1000,1500 and 2000 μm from the fovea) at the horizontal (nasal/temple) and vertical (superior/inferior) directions.Results The subfoveal choroidal thickness was (235.53 ± 51.77) μm and (273.45 ± 60.3) μm in TDS patients and control respectively,the difference was significant(t=-2.612,P=0.011).The difference of the choroidal thickness of the other 8 horizontal sites (F=24.180) and 8 vertical sites (F=23.390) in TDS group was statistically significant (P =0.000).The TDS choroidal thickness of all horizontal sites except nasal 1000 μm site was thinner than corresponding sites of the control group (P＜0.05).The TDS choroidal thickness of the subfoveal site and 4 inferior vertical sites was thinner than corresponding sites of the control group (P＜0.05).The subfoveal RPE thickness was (32.56±5.00) μm and (36.58±3.60) μm in TDS patients and control respectively,the difference was significant (t =-3.567,P =0.001).The subfoveal RPE thickness was the thickest among other 16 sites in both groups,and the TDS RPE thickness of all sites was thinner than control group,the difference was statistically significant (P＜0.05).Conclusion The choroidal and RPE thickness of TDS patient was thinner than normal subjects. Key words: Optic disk/pathology; Choroid/anatomy & histology; Retinal pigment epithelium/anatomy & histology

Ultra-high resolution optical coherence tomography analysis of bull's eye maculopathy in chloroquine users

Purpose: Register and compare anatomical changes, structural and quantitative found in optical coherence tomography Stratus and Topcon 3D in chronic users of chloroquine. Methods: Five patients were diagnosed with toxic bull's eye maculopathy was submitted to macular optical coherence tomography examination (Stratus and Topcon 3D). Results: Both tools demonstrated an increase reflectivity of choriocapillaris unit just foveal retinal pigment epithelium atrophy. However, Topcon 3D provided to all patients better description of the line corresponding to the transition between inner and outer segments of photoreceptors. Using the possibility of assembling threedimensional images and subtraction selective retinal layers, we found a lesion with a target that reflects the greater thickness of retinal pigment epithelium in central and parafoveal region that is matched to preserve macular photoreceptors. Conclusion: it was observed better resolution and faster image capture by Topcon 3D than Stratus OCT, that provided more detailed analysis of the line corresponding to transition between outer and inner segment of photoreceptors in macular region. With Topcon 3D, it was possible to evaluate soundly the thickness of retinal pigment epithelium in central and parafoveal region that caused an increase reflectivity of choriocapillaris creating a image with a target unpublished before.