Retinal Microcirculation Investigation in Type I and II Diabetic Patients Without Retinopathy Using an Adaptive Optics Retinal Camera (original) (raw)
Related papers
Journal of Diabetes Research, 2022
The current research approaches the retinal microvasculature of healthy volunteers (17 subjects), patients with diabetes mellitus without retinopathy (19 subjects), and of diabetic patients with nonproliferative (17 subjects) and proliferative (21 subjects) diabetic retinopathy, by using adaptive optics ophthalmoscopy and optical coherence ophthalmoscopy angiography. For each imaging technique, several vascular parameters have been calculated in order to achieve a comparative analysis of these imaging biomarkers between the four studied groups. The results suggest that diabetic patients with or without diabetic retinopathy prove signs of retinal arteriole structural alterations, mainly showed by altered values of wall to lumen ratio, calculated for the superior or inferior temporal branch of the central retinal artery, near the optic nerve head, and significant changes of the vascular density in the retinal superficial capillary plexus. Both adaptive optics ophthalmoscopy and optica...
Journal of Diabetes Research
Optical coherence tomography angiography (OCT-A) has recently improved the ability to detect subclinical and early clinically visible microvascular changes occurring in patients with diabetes mellitus (DM). The aim of the present study is to evaluate and compare early quantitative changes of macular perfusion parameters in patients with DM without DR and with mild nonproliferative DR (NPDR) evaluated by two different swept-source (SS) OCT-A instruments using two scan protocols (3×3 mm and 6×6 mm). One hundred eleven subjects/eyes were prospectively evaluated: 18 healthy controls (control group), 73 eyes with DM but no DR (no-DR group), and 20 eyes with mild NPDR (DR group). All quantitative analyses were performed using ImageJ and included vessel and perfusion density, area and circularity index of the FAZ, and vascular complexity parameters. The agreement between methods was assessed according to the method of Bland-Altman. A significant decrease in the majority of the considered p...
Biomedicines
Introduction. Diabetes mellitus contributes to the development of microvascular complications in the eye. Moreover, it affects multiple end organs, including brain damage, leading to premature death. The use of adaptive optics technique allows to perform non-invasive in vivo assessment of retinal vessels and to identify changes in arterioles about 100 μm in diameter. The retinal vasculature may be a model of the cerebral vessels both morphologically and functionally. Aim. To evaluate morphological parameters of retinal arterioles in patients with type 1 diabetes mellitus (DM1). Material and methods. The study included 22 DM1 patients (13 females) aged 43.00 ± 9.45 years with a mean diabetes duration of 22.55 ± 10.05 years, and 23 healthy volunteers (10 females) aged 41.09 ± 10.99 years. Blood pressure, BMI, waist circumference, and metabolic control markers of diabetes were measured in both groups. Vascular examinations were performed using an rtx1 adaptive optics retinal camera (Im...
Medicine
Fluorescein angiography has been so far the gold-standard test to assess diabetic macular ischemia (DMI), a cause of irreversible visual impairment in diabetic patients. The aim of this study was to investigate foveal avascular zone (FAZ) and perifoveal microcirculation changes in eyes with nonproliferative diabetic retinopathy (NPDR) using optical coherence tomography angiography (OCTA), a new and noninvasive vascular imaging technique. Cross-sectional study including eyes of diabetic patients with NPDR. All patients underwent medical history, best-corrected visual acuity (BCVA) measurement, slit-lamp and fundus examination, multicolor imaging, SD-OCT, and swept-source OCT. OCTA was performed in order to assess macular superficial and deep capillary plexus, and swept-source OCT was performed to evaluate the central choroidal thickness. Fifty-eight eyes of 35 patients with a mean age of 61.8 years (±12.1) with mean HbA1C level of 7.6% (±1.5) were included in this study. Among them, 19 eyes had mild NPDR, 24 eyes had moderate NPDR, and 15 eyes had severe NPDR. There was a significant progression between NPDR stages for FAZ grade (P < 0.0001), surface (P = 0.0036) and perimeter (P = 0.0001), and for superficial capillary plexus nonperfusion index (NPI) (P = 0.0009). Moreover, a significant correlation was found between NPI and BCVA (P = 0.007). OCT angiography is a useful noninvasive tool to explore early phases of diabetic retinopathy, which are not routinely explore with fluorescein angiography and not precisely enough with color photographs. NPI and foveal avascular zone parameters are correlated with glycated hemoglobin in patients with NPDR. If confirmed by further studies, these results could represent a mean to sensibilize diabetic patients to their disease. Abbreviations: BCVA = best-corrected visual acuity, DMI = diabetic macular ischemia, ETDRS = Early Treatment Diabetic Retinopathy Study, FAZ = foveal avascular zone, HbA1C = glycated hemoglobin A1C, NPDR = nonproliferative diabetic retinopathy, NPI = nonperfusion index, OCTA = optical coherence tomography angiography.
Noninvasive temporal detection of early retinal vascular changes during diabetes
Scientific Reports, 2020
Diabetes associated complications, including diabetic retinopathy and loss of vision, are major health concerns. Detecting early retinal vascular changes during diabetes is not well documented, and only few studies have addressed this domain. The purpose of this study was to noninvasively evaluate temporal changes in retinal vasculature at very early stages of diabetes using fundus images from preclinical models of diabetes.Non-diabetic and Akita/+ male mice with different duration of diabetes were subjected to fundus imaging using a Micron III imaging system. The images were obtained from 4 weeks-(onset of diabetes), 8 weeks-, 16 weeks-, and 24 weeks-old male Akita/+ and nondiabetic mice. In total 104 fundus images were subjected to analysis for various feature extractions. A combination of Canny Edge Detector and Angiogenesis Analyzer plug-ins in ImageJ were utilized to quantify various retinal vascular changes in fundus images. Statistical analyses were conducted to determine significant differences in the various extracted features from fundus images of diabetic and non-diabetic animals. Our novel image analysis method led to extraction of over 20 features. These results indicated that some of these features were significantly changed with a short duration of diabetes, and others remained the same but changed after longer duration of diabetes. These patterns likely distinguish acute (protective) and chronic (damaging) associated changes with diabetes. We show that with a combination of various plugging one can extract over 20 features from retinal vasculature fundus images. These features change during diabetes, thus allowing the quantification of quality of retinal vascular architecture as biomarkers for disease progression. In addition, our method was able to identify unique differences among diabetic mice with different duration of diabetes. The ability to noninvasively detect temporal retinal vascular changes during diabetes could lead to identification of specific markers important in the development and progression of diabetes mediatedmicrovascular changes, evaluation of therapeutic interventions, and eventual reversal of these changes in order to stop or delay disease progression. Many studies have now demonstrated that the eyes provide a window for assessing the health and integrity of the systemic vasculature and the central nervous system, as several diseases present signature changes in the retinal vasculature features. Nowhere else in the body can internal health be noted without substantial intervention. During manual ocular examination, some features like the health of optic disc, nerves and macula, and retinal blood vessel architecture can be easily detected. Patients are commonly examined for changes in the retinal arteries and nerves by shining a light through the iris on to the back of the eye using an ophthalmoscope. Traditionally, manual observations via an ophthalmoscope has been utilized for various diagnoses 1. However, recently new hardware and software are used to digitalize ocular fundus images 2. This digitalization of images is allowing for more precise measurements of ocular changes, creating opportunities to identify and monitor ocular and systemic diseases earlier than traditional methods 3. Building on this trend towards digitalized retinal
JAMA Ophthalmology, 2017
IMPORTANCE Quantitative measurements based on optical coherence tomographic angiography (OCTA) may have value in managing diabetic retinopathy (DR), but there is limited information on the ability of OCTA to distinguish eyes with DR. OBJECTIVE To evaluate the ability of measurements of retinal microvasculature using OCTA to distinguish healthy eyes from eyes with DR. DESIGN, SETTING, AND PARTICIPANTS In this prospective cross-sectional study, OCTA was used to examine the eyes of participants with type 2 diabetes with or without DR and the eyes of participants without diabetes from September 17, 2015, to April 6, 2016. Density maps based on superficial retinal layer (SRL) and deeper retinal layer (DRL) images were generated after a method to remove decorrelation tails was applied to the DRL images. EXPOSURES Both eyes of each participant were examined by means of a 3-mm OCTA scan and 7-field fundus photography using the Diabetic Retinopathy Severity Scale. MAIN OUTCOMES AND MEASURES Two measures were examined: perfusion density, based on the area of vessels, and vessel density, based on a map with vessels of 1-pixel width. The size of the foveal avascular zone was also calculated automatically, and so was the area under the receiver operating characteristic curve. RESULTS A total of 50 eyes from 26 participants with diabetes (10 women and 16 men; mean [SD] age, 64.9 [7.5] years) and 50 healthy eyes from 25 participants without diabetes (14 women and 11 men; mean [SD] age, 64.0 [7.1] years) were imaged. All participants were white. Vessel density measured in the SRL had the highest area under the receiver operating characteristic curve (0.893 [95% CI, 0.827-0.959]), compared with perfusion density in the SRL (0.794 [95% CI, 0.707-0.881]), foveal avascular zone area (0.472 [95% CI, 0.356-0.588]), and vessel density in the DRL (0.703 [95% CI, 0.601-0.805]). Vessel density in the SRL negatively correlated with best-corrected visual acuity (r =-0.28; P = .05) and severity of DR (r =-0.46; P = .001). Density metrics correlated with age. No correlation was detected between vascular density or foveal avascular zone metrics and hemoglobin A 1C or duration of diabetes. CONCLUSIONS AND RELEVANCE Vessel density measured by OCTA provides a quantitative metric of capillary closure that correlates with severity of DR and may allow staging, diagnosis, and monitoring that do not require subjective evaluation of fundus images.
Investigative Opthalmology & Visual Science, 2020
We hypothesize that patients with type 1 diabetes (T1D) may have abnormal retinal vascular responses before diabetic retinopathy (DR) is clinically evident. Optical coherence tomography angiography (OCTA) was used to dynamically assess the retinal microvasculature of diabetic patients with no clinically visible retinopathy. METHODS. Controlled nonrandomized interventional study. The studied population included 48 eyes of 24 T1D patients and 24 demographically similar healthy volunteers. A commercial OCTA device (AngioVue) was used, and two tests were applied: (1) the hypoxia challenge test (HCT) and (2) the handgrip test to induce a vasodilatory or vasoconstrictive response, respectively. The HCT is a standardized test that creates a mild hypoxic environment equivalent to a flight cabin. The handgrip test (i.e., isometric exercise) induces a sympathetic autonomic response. Changes in the parafoveal superficial and deep capillary plexuses in both tests were compared in each group. Systemic cardiovascular responses were also comparatively evaluated. RESULTS. In the control cohort, the vessel density of the median parafoveal superficial and deep plexuses increased during hypoxia (F 1,23 = 15.69, P < 0.001 and F 1,23 = 16.26, P < 0.001, respectively). In the T1D group, this physiological response was not observed in either the superficial or the deep retinal plexuses. Isometric exercise elicited a significant decrease in vessel density in both superficial and deep plexuses in the control group (F 1,23 = 27.37, P < 0.0001 and F 1,23 = 27.90, P < 0.0001, respectively). In the T1D group, this response was noted only in the deep plexus (F 1,23 = 11.04, P < 0.01). CONCLUSIONS. Our work suggests there is an early impairment of the physiological retinal vascular response in patients with T1D without clinical diabetic retinopathy.
Acta Ophthalmologica, 2017
Purpose: Diabetic retinopathy (DR) can lead to significant vision loss and blindness and has a particularly high prevalence in patients with type 1 diabetes (DM1). In this study, we investigate quantitative differences in optical coherence tomography angiography (OCTA) data between DM1 patients with no or mild signs of retinopathy and non-diabetic subjects. Methods: Optical coherence tomography angiography (OCTA) imaging was performed on DM1 patients with no or mild nonproliferative diabetic retinopathy and healthy, age-matched controls. Parafoveal vessel density and foveal avascular zone (FAZ) area in the deep capillary plexus (DCP) and superficial capillary plexus (SCP) were calculated with automated quantification software and compared between patient cohorts. Results: A significant decrease in parafoveal vessel density was seen in the DCP of DM1 patients compared to non-diabetic controls (57.0 AE 3.3% versus 60.7 AE 2.4%, p < 0.001). There was no significant difference in SCP parafoveal vessel density, DCP FAZ area, or SCP FAZ area between cohorts. Conclusion: M1 patients with no or mild signs of retinopathy have reduced parafoveal vessel density in the DCP on OCTA when compared to non-diabetic controls. These OCTA findings suggest that parafoveal capillary nonperfusion is an early process in DM1-related retinal changes and occurs initially at the level of the DCP. Further investigation is needed to understand the prognostic role of these vascular changes.
International Journal of Retina
Introduction: Diabetic Retinopathy (DR) is a common microvascular complication in patients with Diabetes Mellitus (DM) that can cause visual impairment and blindness in adult populations. Retinal microvascular changes, reflecting capillary drop out, non perfusion, and retinal ischemia seen in patients with DM can be assessed not only qualitatively, but also quantitatively with the introduction of a new, non invasive imaging modality Optical Coherence Tomography Angiography (OCTA), avoiding potential advese risks that can occur with the use of dye-injection imaging technique. We quantified retinal microvascular changes in healthy control eyes and Diabetic Retinopathy using OCTA. Methods: A cross sectional study included 13 eyes of 9 patients with DR, consists of 11 eyes with Non Proliferative Diabetic Retinopathy (NPDR) and 2 eyes with Proliferative Diabetic Retinopathy (PDR) and 5 eyes of 5 age-matched controls. Participants were imaged with commercial OCTA device (CIRRUS HD-OCT 500...