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Diabetic Retinopathy
Published in Jahangir Moini, Matthew Adams, Anthony LoGalbo, Complications of Diabetes Mellitus, 2022
Jahangir Moini, Matthew Adams, Anthony LoGalbo
Prior to proliferative retinopathy, macular edema or ischemia begins to cause visual problems. Sometimes, there is no vision loss even if retinopathy becomes advanced. Initial signs of nonproliferative retinopathy include capillary microaneurysms, soft exudates known as cotton-wool spots, dot-and-blot hemorrhages of the retina, and hard exudates. Hard exudates suggest that chronic edema is present. Cotton-wool spots are microinfarctions of the retinal nerve fiber layer that result in opacification of the retina. They have fuzzy edges, a white color, and they obscure the blood vessels lying below them. In later states, signs include macular edema, intraretinal microvascular abnormalities, and venous dilation. Macular edema can be seen during slit-lamp biomicroscopy. It appears as elevations and blurring of the retinal layers.
Nerve and Retinal Changes in Experimental Diabetes
Published in John H. McNeill, Experimental Models of Diabetes, 2018
Human diabetic retinopathy is classified into progressive stages, namely, background (nonproliferative) retinopathy, severe or advanced background (preproliferative) retinopathy, and proliferative retinopathy. Background retinopathy consists of capillary microangiopathy, macular edema and soft exudate, and retinal hemorrhages and exudate. Capillary microangiopathy structurally shows basement membrane thickening, loss of pericytes, microvascular obstruction, permeability changes, and microaneurysms. Cotton wool spots (soft exudate), representing microinfracts of the nerve fiber layer, were once considered an important predictor of proliferative diabetic retinopathy. However, this has not been substantiated.224 Profuse retinal hemorrhages and exudate, venous dilatation and beading, widespread capillary nonperfusion, and intraretinal microvascular abnormalities (IRMA), consisting of telangiectatic vessels shunting blood around areas of nonperfusion, are the characteristic features of preproliferative retinopathy. Patients with these lesions are prone to develop proliferative retinopathy. Proliferative retinopathy is characterized by neovascularization. New blood vessels form on the optic disk, within the retina, on the retinal surface, or inside the vitreous. Neovascularization eventually leads to bleeding, fibrosis, and tractional retinal detachment. An outline of lesions in the various stages of diabetic retinopathy is presented in Figure 6.3.
Sensory organs
Published in Aida Lai, Essential Concepts in Anatomy and Pathology for Undergraduate Revision, 2018
Pre-proliferative retinopathyArteriolar narrowingMultiple cottonwool spotsIntraretinal microvascular abnormalities (IRMA)Macular oedema
The diagnostic value of systemic immune-inflammation index in diabetic macular oedema
Published in Clinical and Experimental Optometry, 2022
Ahmet Elbeyli, Bengi Ece Kurtul, Sait Coskun Ozcan, Deniz Ozarslan Ozcan
Severe non-proliferative diabetic retinopathy (level 53) was defined as: microaneurysms and one or more of the following: any two or three characteristics from level 47, haemorrhages/microaneurysms equalling or exceeding those in four or five fields, intraretinal microvascular abnormalities equalling or exceeding those, or venous beading in two or more fields. Moderate non-proliferative diabetic retinopathy (levels 43 through 47) was defined as microaneurysms and one or more of the following: haemorrhages/microaneurysms equalling or exceeding those in standard photo one in four or five fields, haemorrhages/microaneurysms equalling or exceeding those in one field, and intraretinal microvascular abnormalities in one to three fields. Microaneurysms and one or more of the following: both intraretinal microvascular abnormalities and haemorrhage/microaneurysm characteristics from level 43, intraretinal microvascular abnormalities in four or five fields, haemorrhages/microaneurysms equalling or exceeding those in two or three fields, or venous beading in one field. DME was demonstrated by the presence of increased central macular thickness due to cystoid changes, oval and round parts of the image indicating low reflect-ability in horizontal cross-sections of the central fovea as follows: (1) retinal thickening at or within 500 mm from the centre of the macula (2) hard exudates at or within 500 mm from the centre of the macula if accompanied by thickening of the adjacent retina and (3) a zone of retinal thickening, one disc area of larger in size, located one disc diameter or less from the centre of the macula.
Prevalence of Diabetic Eye Diseases in American Indians and Alaska Natives (AI/AN) as Identified by the Indian Health Service’s National Teleophthalmology Program Using Ultrawide Field Imaging (UWFI)
Published in Ophthalmic Epidemiology, 2022
Stephanie Jo Fonda, Sven-Erik Bursell, Drew G. Lewis, Dawn Clary, Dara Shahon, Paolo S. Silva
For the determination of DR and DME severity, previous studies have found that UWFI has perfect agreement with ETDRS photography in 84% of cases and agreement within one level of disease severity in 91% of cases (unweighted κ = 0.79).23 Detailed protocols for evaluating UWF images have been described.17 Graders, who are licensed, certified optometrists supervised by an ophthalmologist, evaluate images on standardized workstations at a centralized reading center at Phoenix Indian Medical Center. Each image is evaluated for distribution of hemorrhages and/or microaneurysms, venous beading, intraretinal microvascular abnormalities and new vessels on the retina. Any DR lesion type is considered predominantly peripheral when more than 50% of it is observed outside the ETDRS standard fields [i.e., ‘predominantly peripheral lesion’ (PPL)].17 UWFI, due to its wide view of the retina, facilitates views of peripheral lesions that is not achievable with the aforementioned NMFP technology. Graders determine whether the presence of PPL increase overall DR severity.
Relation Between Platelet Reactivity Levels and Diabetic Retinopathy Stage in Patient with Type 2 Diabetes Mellitus by Using Multiplate Whole Blood Aggregometry
Published in Seminars in Ophthalmology, 2021
Işıl Kutlutürk Karagöz, Ali Karagöz, Flora Özkalaycı, Cem Doğan, Gonenc Kocabay, Ahmet Elbay
Diabetic retinopathy (DR) is an important microvascular complication of diabetes mellitus (DM), and it is associated with significant morbidity and mortality. Moreover, it is one of the leading causes of preventable vision loss in adults.1 Poor glycaemic control plays a major role in the development of the microvascular complications,2 leading to neo-angiogenesis, fibrous lesions, microaneurysms, haemorrhages, oedema and intraretinal microvascular abnormalities, which can be determined by ophthalmic examination.3 Although it is well-known that chronic hyperglycaemia could result in DR, and worsen it, the underlying mechanisms remain unclear.4 One of the possible underlying mechanisms of platelet reactivity is due to DM and chronic hyperglycaemia.5 In a study, Boeri et al. demonstrated that the size and number of platelet-fibrin thrombi in the retinal capillaries of patients with DM were likely to be greater than those without DM. It has been indicated that retinal ischemia and the capillary obliteration may be targeted for earlier treatment of DR.6