-
1.
Imaging the eye and its relevance to diabetes care.
Quinn, N, Jenkins, A, Ryan, C, Januszewski, A, Peto, T, Brazionis, L
Journal of diabetes investigation. 2021;(6):897-908
Abstract
Diabetes is a major cause of vision loss globally, yet this devastating complication is largely preventable. Early detection and treatment of diabetic retinopathy necessitates screening. Ocular imaging is widely used clinically, both for the screening and management of diabetic retinopathy. Common eye conditions, such as glaucoma, cataracts and retinal vessel thrombosis, and signs of systemic conditions, such as hypertension, are frequently revealed. As well as imaging by a skilled clinician during an eye examination, non-ophthalmic clinicians, such as general practitioners, endocrinologists, nurses and trained health workers, can also can carry out diabetic eye screening. This process usually comprises local imaging with remote grading, mostly human grading. However, grading incorporating artificial intelligence is emerging. In a clinical research context, retinal vasculature analyses using semi-automated software in many populations have identified associations between retinal vessel geometry, such as vessel caliber, and the risk of diabetic retinopathy and other chronic complications of type 1 and type 2 diabetes. Similarly, evaluation of corneal nerves by corneal confocal microscopy is revealing diabetes-related abnormalities, and associations with and predictive power for other chronic diabetes complications. As yet, the value of retinal vessel geometry and corneal confocal microscopy measures at an individual level is uncertain. In this article, targeting non-ocular clinicians and researchers, we review existent and emerging ocular imaging and grading tools, including artificial intelligence, and their associations between ocular imaging findings and diabetes and its chronic complications.
-
2.
Obstructive sleep apnea and the retina: a review.
Nakayama, LF, Tempaku, PF, Bergamo, VC, Polizelli, MU, Santos da Cruz, NF, Bittencourt, LRA, Regatieri, CVS
Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine. 2021;(9):1947-1952
Abstract
CITATION This review's objective was to synthesize the literature on the repercussions of obstructive sleep apnea (OSA) in the retinal vascular system. Two independent investigators conducted a search using the MEDLINE/PubMed database using the following terms: sleep apnea syndrome, obstructive sleep apnea, retina, vascular tortuosity, central serous chorioretinopathy, diabetes mellitus, and subfoveal choroidal thickness. Patients with OSA present increased vascular tortuosity compared with patients without OSA, decreased parafoveal and peripapillary vessel density, and increased retinal vein occlusion incidence. In central serous chorioretinopathy patients and patients who are poor responders to intravitreal anti-VEGF (-vascular endothelial growth factor) treatment for macular edema, OSA is more frequent. Macular choroidal thickness alterations are controversial, and OSA may worsen diabetic maculopathy, thus being a risk factor for diabetic retinopathy, proliferative diabetic retinopathy, and macular edema. OSA is a prevalent syndrome with many systemic vascular changes. The retina and choroid are the most affected ocular structures, with primarily vascular changes. New noninvasive technologies such as optical coherence tomography and optical coherence tomography angiography could help to better understand retinal structures and help clarify the ophthalmological repercussions of OSA. CITATION Nakayama LF, Tempaku PF, Bergamo VC, et al. Obstructive sleep apnea and the retina: a review. J Clin Sleep Med. 2021;17(9):1947-1952.
-
3.
Correlation of OCT Angiography Vessel Densities and the Early Treatment Diabetic Retinopathy Study Grading Scale.
Mehta, NS, Lee, JG, Gupta, L, Zhou, DB, Andrade Romo, JS, Castanos, MV, Jansen, M, Ping Chui, TY, Rosen, RB
Ophthalmology. Retina. 2021;(7):714-715
-
4.
Retinal complications of gout: a case report and review of the literature.
Jiang, Y, Brenner, JE, Foster, WJ
BMC ophthalmology. 2018;(1):11
Abstract
BACKGROUND There have been few reported findings of posterior segment complications of gout. While exudative lesions, an increased risk of macular degeneration, and vascular occlusions have been previously reported, to our knowledge, refractile macular lesions have not been reported in a patient with chronic uncontrolled gout. CASE PRESENTATION Highly refractile, crystal-like lesions were found in the macula of a 62 year old male patient with chronically uncontrolled gout. The lesions appeared at the termination of retinal arterioles and were located at the level of the retinal pigment epithelium. The lesions did not stain with fluorescein and were associated with larger areas geographic atrophy. Review of the patient's blood tests revealed well-controlled vasculopathic risk factors. Fundus appearance and best-corrected visual acuity remained stable over 12 months of follow-up during which the uric acid levels were well controlled. CONCLUSION Retinopathy may be associated with chronically uncontrolled gout and patients with visual complaints should undergo a dilated examination in addition to the typical anterior segment slit-lamp exam.
-
5.
Optical Coherence Tomography Angiography in Healthy Subjects and Diabetic Patients.
Coscas, G, Lupidi, M, Coscas, F, Chhablani, J, Cagini, C
Ophthalmologica. Journal international d'ophtalmologie. International journal of ophthalmology. Zeitschrift fur Augenheilkunde. 2018;(2-3):61-73
Abstract
Fluorescein angiography and indocyanine green angiography provide information about the normal retinal and choroidal vascular perfusion. They allow the evaluation of different diseases and increase the capability to define and diagnose several pathological conditions. Fluorescein angio graphy is the "gold standard" in imaging the retinal vascular bed and its changes, although not all the different layers of the capillary network can be visualized in a bidimensional examination. Optical coherence tomography angiography allows a depth-resolved visualization of the retinal and choroidal microvasculature, by calculating the difference (decorrelation) between static and nonstatic tissue. Given that the main moving elements in the eye fundus are contained in vessels, determining a vascular decorrelation signal permits a three-dimensional visualization of the retinal and choroidal vascular network without the administration of an intravenous dye. Moreover, a complete morphofunctional assessment may help in defining both the origin and the clinical activity of different vascular diseases such as diabetic retinopathy.
-
6.
OCT angiography and visible-light OCT in diabetic retinopathy.
Nesper, PL, Soetikno, BT, Zhang, HF, Fawzi, AA
Vision research. 2017;:191-203
-
-
Free full text
-
Abstract
In recent years, advances in optical coherence tomography (OCT) techniques have increased our understanding of diabetic retinopathy, an important microvascular complication of diabetes. OCT angiography is a non-invasive method that visualizes the retinal vasculature by detecting motion contrast from flowing blood. Visible-light OCT shows promise as a novel technique for quantifying retinal hypoxia by measuring the retinal oxygen delivery and metabolic rates. In this article, we discuss recent insights provided by these techniques into the vascular pathophysiology of diabetic retinopathy. The next milestones for these modalities are large multicenter studies to establish consensus on the most reliable and consistent outcome parameters to study diabetic retinopathy.
-
7.
Noninvasive Retinal Markers in Diabetic Retinopathy: Advancing from Bench towards Bedside.
Blindbæk, SL, Torp, TL, Lundberg, K, Soelberg, K, Vergmann, AS, Poulsen, CD, Frydkjaer-Olsen, U, Broe, R, Rasmussen, ML, Wied, J, et al
Journal of diabetes research. 2017;:2562759
Abstract
The retinal vascular system is the only part of the human body available for direct, in vivo inspection. Noninvasive retinal markers are important to identity patients in risk of sight-threatening diabetic retinopathy. Studies have correlated structural features like retinal vascular caliber and fractals with micro- and macrovascular dysfunction in diabetes. Likewise, the retinal metabolism can be evaluated by retinal oximetry, and higher retinal venular oxygen saturation has been demonstrated in patients with diabetic retinopathy. So far, most studies have been cross-sectional, but these can only disclose associations and are not able to separate cause from effect or to establish the predictive value of retinal vascular dysfunction with respect to long-term complications. Likewise, retinal markers have not been investigated as markers of treatment outcome in patients with proliferative diabetic retinopathy and diabetic macular edema. The Department of Ophthalmology at Odense University Hospital, Denmark, has a strong tradition of studying the retinal microvasculature in diabetic retinopathy. In the present paper, we demonstrate the importance of the retinal vasculature not only as predictors of long-term microvasculopathy but also as markers of treatment outcome in sight-threatening diabetic retinopathy in well-established population-based cohorts of patients with diabetes.
-
8.
Mechanism of worsening diabetic retinopathy with rapid lowering of blood glucose: the synergistic hypothesis.
Jingi, AM, Tankeu, AT, Ateba, NA, Noubiap, JJ
BMC endocrine disorders. 2017;(1):63
Abstract
Insulin treatment has been associated with a paradoxical worsening of diabetes retinopathy since many years in European cohorts. Recently, this issue has been stressed by some studies conducted in other parts of the world. However, the mechanism underlying such evolution is not well understood. An osmotic theory has been evocated but failed to explain the clinical features of the disease. Considering recent findings from basic and clinical research, we discuss the possibility of a synergistic hypothesis based on the simultaneous action of insulin and vascular endothelial growth factor on eye blood vessels. We postulate that exogenous insulin could act synergistically with the vascular endothelial growth factor expressed by ischemic retina so as to trigger vascular proliferation and the worsening of diabetes retinopathy.
-
9.
Evaluating ocular blood flow.
Maram, J, Srinivas, S, Sadda, SR
Indian journal of ophthalmology. 2017;(5):337-346
-
-
Free full text
-
Abstract
Studies have shown that vascular impairment plays an important role in the etiology and pathogenesis of various ocular diseases including glaucoma, age-related macular degeneration, diabetic retinopathy, and retinal venous occlusive disease. Thus, qualitative and quantitative assessment of ocular blood flow (BF) is a topic of interest for early disease detection, diagnosis, and management. Owing to the rapid improvement in technology, there are several invasive and noninvasive techniques available for evaluating ocular BF, with each of these techniques having their own limitations and advantages. This article reviews these important techniques, with a particular focus on Doppler Fourier domain optical coherence tomography (OCT) and OCT-angiography.
-
10.
Vascular Changes and Neurodegeneration in the Early Stages of Diabetic Retinopathy: Which Comes First?
Jonsson, KB, Frydkjaer-Olsen, U, Grauslund, J
Ophthalmic research. 2016;(1):1-9
Abstract
INTRODUCTION Neurodegeneration is an early component of diabetic retinopathy (DR). It is unclear whether neurodegeneration is an independent factor or a consequence of damaged retinal vasculature. The aims of this study were to review the literature concerning neurodegeneration in diabetic patients without or with early DR, and to examine whether neurodegeneration precedes visible vasculopathy in the pathogenesis of DR. METHODS A systematic literature search was performed to identify studies which used optical coherence tomography (OCT) or multifocal electroretinography (mfERG) to detect neurodegeneration in patients with no or mild DR as compared to healthy controls. Outcome measures were mean retinal thickness (RT), mean retinal nerve fiber layer (RNFL) thickness and ganglion cell layer (GCL) thickness. Also, mfERG amplitude and implicit time were analyzed. RESULTS Eleven studies which used mfERG and/or OCT to detect neurodegeneration were included. Two OCT studies found significant thinning of RT, 2 found thinning of RNFL, whereas 1 found thickening of RT, RNFL and GCL in patients without DR. Two mfERG studies found a significant delay of implicit time in the same patient group. Retinal thinning and delay of implicit time were also detected in patients with mild DR. CONCLUSION Retinal neurodegeneration is an early component of DR, which can precede visible vasculopathy.