Optical Coherence Tomography (Angiography) Biomarkers in the Assessment and Monitoring of Diabetic Macular Edema

Retinopathy is one of the most severe diabetes-related complications, and macular edema is the major cause of central vision loss in patients with diabetes mellitus. Significant progress has been made in recent years in optical coherence tomography and angiography technology. At the same time, various parameters have been attributed the role of biomarkers creating the frame for new monitoring and treatment strategies and offering new insights into the pathogenesis of diabetic retinopathy and diabetic macular edema. In this review, we gathered the results of studies that investigated various specific OCT (angiography) parameters in diabetic macular edema, such as central subfoveal thickness (CST), cube average thickness (CAT), cube volume (CV), choroidal thickness (CT), retinal nerve fiber layer (RNFL), retinal thickness at the fovea (RTF), subfoveal choroidal thickness (SFCT), central macular thickness (CMT), choroidal vascularity index (CVI), total macular volume (TMV), central choroid thickness (CCT), photoreceptor outer segment (PROS), perfused capillary density (PCD), foveal avascular zone (FAZ), subfoveal neuroretinal detachment (SND), hyperreflective foci (HF), disorganization of the inner retinal layers (DRIL), ellipsoid zone (EZ), inner segment/outer segment (IS/OS) junctions, vascular density (VD), deep capillary plexus (DCP), and superficial capillary plexus (SCP), in order to provide a synthesis of biomarkers that are currently used for the early diagnosis, assessment, monitoring, and outlining of prognosis

Interleaved Optical Coherence Tomography: Clinical and Laboratory Biomarkers in Patients with Diabetic Macular Edema

(1) Background: The global burden of diabetes mellitus (DM) has been estimated to reach 600 million patients worldwide by 2040. Approximately 200 million people will develop diabetic retinopathy within this time frame. Diabetic macular edema (DME) is a severe, vision-threatening complication that can develop at any stage of diabetic retinopathy, and it represents the main cause of vision loss in patients with DM. Its harmful consequences on visual function could be prevented with timely recognition and treatment. (2) Methods: This study assessed the clinical (demographic characteristics, diabetic evolution, and systemic vascular complications); laboratory (glycated hemoglobin, metabolic parameters, capillary oxygen saturation, and renal function); ophthalmologic exam; and spectral-domain optical coherence tomography (SD–OCT) (macular volume, central macular thickness, maximal central thickness, minimal central thickness, foveal thickness, superior inner, inferior inner, nasal inner, temporal inner, inferior outer, superior outer, nasal outer, and temporal outer thicknesses, disruption of the ellipsoid zone, and disruption of the inner retinal layers (DRIL) parameters in three groups of individuals: healthy controls (HC), patients with DME and type 1 DM (T1DM—group A), and patients with DME and type 2 DM (T2DM—group B) to identify novel correlations between them that would open a path to new pathogenetic hypotheses and, implicitly, to the identification of new therapeutic methods, as part of a tailored treatment within the concept of precision medicine. (3) Results: The duration of DM was significantly longer in group A as compared with group B, as were the prevalence of smoking and systemic vascular complications. Capillary oxygen saturation and estimated glomerular filtration rates were significantly lower, and serum creatinine levels were significantly higher in group A as compared to group B. Regarding the OCT findings, DME had a predominantly eccentric pattern, and the right eye was more severely affected in both groups of patients. Significantly higher values were obtained in group B as compared to group A for the following OCT biomarkers: macular volume, central macular thickness, maximal central thickness, minimal central thickness, foveal thickness, superior inner, inferior inner, nasal inner, inferior outer and nasal outer thickness. The disruption of the ellipsoid zone was significantly more prevalent within group A, whereas the overall disruption of the retinal inner layers (DRIL) was identified significantly more frequently in group B. (4) Conclusions: Whereas systemic and laboratory biomarkers were more severely affected in patients with DME and T1DM, the OCT quantitative biomarkers revealed significantly higher values in patients with DME and T2DM

Circumpapillary Retinal Nerve Fiber Layer OCT Imaging in a Parkinson’s Disease Cohort—A Multidisciplinary Approach in a Clinical Research Hospital

(1) Background: The purpose of this paper is to report the data of the first study in a Clinical Research Hospital, in the Transylvania region, focusing on the Spectral Domain Optical Coherence Tomography (SD-OCT) measurements in the early stages of Parkinson’s disease (PD), and to compare the results with age-matched healthy controls. (2) Methods: This study assessed the circumpapillary retinal nerve fiber layer (cpRNFL) SD-OCT measurements (Heidelberg Spectralis, Heidelberg Engineering, Germany) of two study groups: patients suffering from PD (Hoehn−Yahr stages 1–3) and healthy controls. Secondary objectives were to investigate the reported visual symptoms by evaluating the color vision, contrast sensitivity, and the central visual defects for macular disease using standardized charts. Subjects with prior history of ophthalmologic diseases, advanced stages of PD (Hoehn−Yahr stages 4–5), or with psychiatric conditions were not included in this study. The same team of neurologists and ophthalmologists evaluated all individuals in order to have comparable data and to eliminate inter-examiner differences. All subjects were recruited from the same Clinical Research Hospital in the Transylvania region, Romania. (3) Results: 72% of the PD patients (n = 17) in this study reported visual symptoms. In respect to the ophthalmologic chart evaluation for PD patients, the most frequent disturbances were identified in the Ishihara color perception testing (33%). The regression analysis showed significant results for the Ishihara testing in relation to the cpRNFL thinning in the temporal retinal sectors for both eyes. cpRNFL thinning was predominantly contralateral to the parkinsonism (p = 0.001). The temporal and global values of the cpRNFL were significantly lower in all PD patients < 70 years old, compared to the age-matched healthy controls. (4) Conclusions: Specific patterns of cpRNFL thinning were found in the PD subjects younger than 70 years. A multidisciplinary approach is essential for a complete evaluation of PD patients