Idiopathic Epiretinal Membrane: Microvasculature Analysis with Optical Coherence Tomography and Optical Coherence Tomography Angiography

Background: The present study examined the relationships among macular microvasculature, retinal structure, and epiretinal membrane (ERM) and explored the utility of optical coherence tomography (OCT) angiography (OCTA) in idiopathic ERM assessment. Methods: The study sample comprised 276 eyes of 276 patients. A total of 154 eyes with ERM and 122 normal (control) eyes were analyzed. Only one eye of each participant was randomly selected for posterior segment imaging. Each patient underwent OCT and OCTA. Images were analyzed with AngioTool 0.6. Results: Foveal avascular zone was significantly smaller in the ERM group (p = 0.044). Average retinal thickness and foveal thickness were significantly higher in the ERM group (both p = 0.001). Moreover, 64 (41.5%) patients exhibited no metamorphopsia, while 46 (29.8%) and 44 (28.7%) patients exhibited moderate and extensive metamorphopsias, respectively. Meanwhile, FAZ was negatively correlated with central retinal thickness in the ERM group. The vessel area (p = 0.0017) and vessel percentage area (p = 0.044) were significantly greater in the ERM group. Conclusions: Changes observed in the superficial plexus in OCTA are related to the severity of metamorphopsia and can be further evaluated to support decision making regarding the surgical management of idiopathic ERM.

Normative data on the foveal avascular zone in a young healthy Irish population using optical coherence tomography angiography

Purpose To establish normative data on the size, shape and vascular profile of the foveal avascular zone (FAZ) in a young, healthy, Irish population, using the Cirrus 5000 HD-OCT. Certain diseases may alter FAZ appearance. Normative databases provide normal baseline values for comparison, thus improving diagnostic ability. Methods One hundred and fifty-four subjects aged 18–35 years old were recruited. Superficial FAZ area, diameter, circularity, ganglion cell layer, central macular thickness (CMT), vascular perfusion and density were measured using the Cirrus 5000. Axial length was measured with the IOL Master and blood pressure was measured using the Omron sphygmomanometer. Results Mean FAZ area was 0.22 ± 0.07 mm2, mean CMT was 263.08 ± 18.73μm. Both were larger in females than males (p = 0.022, p = 0.000). Mean vessel density and perfusion central were 14.11 ± 2.77 mm/mm2 and 24.70 ± 4.96% respectively. Both were lower in females (p = 0.010, p = 0.019). Vessel density and perfusion inner correlated positively with minimum ganglion cell layer plus inner plexiform layer (GCL + IPL) thickness (p = 0.001, p = 0.019). CMT correlated positively with vessel density and perfusion central (p = 0.000 for both) and negatively with FAZ area (p = 0.000). Conclusions This study provides normative data for FAZ appearance and vascularity for the first time in a young, healthy, Irish population, using the Cirrus 5000 HD-OCT. Establishing machine and population specific normative data, particularly in relation to vessel density and perfusion is paramount to the early identification of ocular disease using Optical Coherence Tomography Angiography.

The quantitative measurements of choroidal thickness and volume in diabetic retinopathy using optical coherence tomography and optical coherence tomography angiography; correlation with vision and foveal avascular zone

Background To represent choroidal thickness (CT) and choroidal volume (CV) databases in diabetic retinopathy (DR) patients and healthy control participants using optical coherence tomography (OCT) and enhanced depth imaging OCT (EDI-OCT). No study had evaluated CT at all main stages of diabetic retinopathy in a single study. Methods The study included 176 eyes from 93 patients (39–80 years old; 42% females) who were divided into three groups based on DR severity and normal control group: 39 eyes no DR, 64 eyes NPDR, 33 eyes PDR, and 40 eyes normal control. The CT and CV were measured and statistically analyzed. Intra-observer and inter-observer coefficients of repeatability were calculated. Results Subfoveal CT showed persistent thinning from normal group (322.50 ± 69.24) to no-diabetic retinopathy (NDR, 308.33 ± 74.45) to nonproliferative diabetic retinopathy (NPDR, 283.45 ± 56.50) group and then thickening as the patient progressed to proliferative diabetic retinopathy (PDR, 295.17 ± 95.69) (P = 0.087). A significant difference was found between the control group and the NDR, NPDR, and PDR groups in nearly all CT and CV of Early Treatment Diabetic Retinopathy Study macular subfields. Fasting blood sugar (FBS = 189.08 ± 51.3 mg/dl) and diabetes mellitus (DM) duration (13.6 ± 6.5 years) had no noticeable effect on CT. In patients with diabetes, the best-corrected visual acuity (BCVA), diabetic macular edema (DME), and foveal avascular zone (FAZ) were not affected by CT and CV. Conclusions The choroidal thickness decreases from the early stages of diabetic retinopathy up to the NPDR stage, with a subsequent modest rise in CT during the PDR stage. There was no correlation between FBS, diabetes duration, BCVA, DME, and FAZ, and CT.

Time-related OCT-A changes in preclinical retinopathy and their association with systemic factors

Background. Optical coherence tomography angiography (OCT-A) is a promising tool for the detection of microvascular impairment at the preclinical stage of diabetic retinopathy (DR). Evaluation of dynamic OCT-A changes and their association with systemic factors can help to reveal early biomarkers of DR progression.Aim: to evaluate time-related OCT-A changes and their association with systemic factors in type 1 diabetes mellitus (DM1) patients with no apparent DRMaterials and methods. 38 DM1 patients with no apparent DR and 39 healthy volunteers were included in the study. All participants underwent 7-fi eld fundus photography, OCT and OCT-A. We analyzed OCT-A parameters (foveal avascular zone (FAZ) area (mm2), acircularity index (AI), vessel density (VD), skeletonized density (SD)) as well as the results of blood and urea tests.Results. After one year of observation, AI was significantly higher (р = 0.005) and VD0–300 was signifi cantly lower in superfi cial vascular plexus (SVP, p < 0.0001) and deep capillary plexus (DCP, р = 0.032) in DM1 patients. We have also registered a positive correlation between AI and triglycerides (TG) level (r = 0.627, p = 0.007) as well as a negative correlation between ketones and VD (SVP VD0–300: r = –0.695, p = 0.030; intermediate capillary plexus (ICP, VD0–300: r = –0.551, p = 0.041; DCP, VD0–300: r = –0.704, p = 0.003; SVP, VD300–600: r = –0.853, p = 0.001).Conclusions. After one year of observation, we have registered an increase in AI level and a decline in VD in SVP and DCP which can be the earliest signs of DR progression. A signifi cant correlation between these parameters and systemic factors indicates their role as potential DR biomarkers.

OCT-angiography for the diagnosis of radiation maculopathy in patients treated with proton beam therapy: A 2-year prospective study

Purpose Radiation maculopathy (RM) is the leading cause of visual acuity (VA) loss after proton beam therapy (PBT) of choroidal melanoma. The aim of this study was to assess the value of optical coherence tomography-angiography (OCT-A) for the diagnosis of RM in patients with choroidal melanoma treated with PBT. Materials & methods This 2-year prospective, descriptive, single-center study included patients treated with PBT for choroidal melanoma. VA measurement, retinography, OCT and OCT-A were performed. Vascular density (VD) in the superficial capillary plexus (SCP), peri-foveal anastomotic ring changes and foveal avascular zone (FAZ) enlargement were studied. Results Nineteen patients were included in the study. The median baseline melanoma thickness was 5.7 [3.6–8.1] mm. The median melanoma-to-macula distance was 3.5 [2.6–4.6] mm. The earliest signs of RM identified on retinography were hard exudates developing at 12 [12–24] months, followed by retinal hemorrhages at 18 [12–30] months, found in 88.9% and 77.8% of patients respectively. On OCT, the earliest sign was the onset/progression of cystoid macular edema (CME) at 12 [6–12] months, found in 10 patients (52.6%). On OCT-A, 100% of patients presented with a discontinuity of the perifoveal anastomotic ring and a FAZ enlargement after 12 [6–24] months. After 12 months, a VD loss in the SCP by 11.7% and 10.8% compared to baseline, was found in the macular and foveal areas respectively. A significant negative correlation was found between the VA and the VD in the macular SCP (R = −0.43; p = 0.029). Conclusion OCT-A is a reliable and effective diagnostic tool for RM in patients with choroidal melanoma treated with PBT.

Relationship between the sFlt-1/PlGF ratio and the optical coherence tomographic features of chorioretina in patients with preeclampsia

This study aimed to evaluate the correlation between ophthalmologic factors and the serologic indicator soluble fms-like tyrosine kinase 1 (sFlt-1): placental growth factor (PlGF) ratio in patients with preeclampsia using optical coherence tomography (OCT) and OCT angiography (OCT-A). A total of 52 pregnant patients (104 eyes) diagnosed with preeclampsia were recruited during their hospital stay. The associations between the sFlt-1/PlGF ratio and chorioretinal measurements, including the choroidal thickness (CT), foveal avascular zone, vascular density, and ganglion cell layer+ were evaluated. Central and nasal subfield CT of the left eye (p = 0.039; p = 0.010) and nasal subfield CT of the right eye (p = 0.042) were lower in the high sFlt-1/PlGF ratio group (≥38). Pearson’s correlation test showed a negative correlation between the sFlt-1/PlGF ratio and central subfield CT; however, this was not statistically significant (p = 0.648). Linear regression analysis revealed a significant association between the sFlt-1/PlGF ratio and central subfield CT (β coefficient, -6.66; p = 0.01) and between sFlt-1 and central subfield CT (β coefficient, -5.65; p = 0.00). Thus, an increase in the sFlt-1/PlGF ratio resulted in a decrease in central subfield CT.

Microvascular differences in amblyopic subgroups: An observational case–control study

Purpose To determine retinal microvascular differences among amblyopic subgroups and compare them with control eyes. Study Design This study was designed as an observational case–control study. Methods Twenty-three strabismic, 23 anisometropic, 22 meridional, 22 ametropic amblyopic eyes, and 24 healthy control eyes were included. The mean vessel densities in the deep and superficial capillary plexus, the foveal avascular zone area, the choriocapillaris flow area, and the foveal thickness were compared. Results Vessel density was markedly lower in all sectors of the amblyopic subgroups in the deep capillary plexus than in control eyes. Density was significantly lower in the superficial capillary plexus only in ametropic and meridional amblyopic eyes. Among these groups, the meridional amblyopic eyes had the largest choriocapillaris flow area ( p = 0.013) and the lowest vessel density in all sectors ( p < 0.001). The foveal avascular zone area was similar in all groups ( p = 0.561). The fovea was significantly thicker only in the anisometropic and meridional subgroups than control eyes ( p = 0.011, p = 0.001, respectively). The foveal avascular zone area was inversely related to the foveal thickness in all groups. Conclusion Retinal structural and microvascular differences were found among amblyopic subgroups. Optical coherence tomography angiography can noninvasively detect these variations, which may be related to the etiologic factors.