Laser Treatment Modalities for Diabetic Retinopathy

Abstract

Diabetes is a chronic progressive metabolic disorder that is caused by the body's inability to regulate blood glucose levels. If uncontrolled, it can lead to various complications. Among its various complications, longterm diabetes leads to diabetic retinopathy (DR). It is a disease involving blood vessels and the destruction of retinal nerves. It is usually classified into two types: proliferative diabetic retinopathy (PDR) and nonproliferative diabetic retinopathy (NPDR). It progresses and causes loss of vision. The leading cause of loss of vision is diabetic macular edema (DME). The argon laser is used as a modality in the management of PDR. There are various types of laser photocoagulation, such as peripheral retinal laser photocoagulation, focal macular laser photocoagulation, and grid photocoagulation. DR results in various adverse consequences such as vitreous hemorrhage, fibrosis, traction, detachment of the retina, and glaucoma. To assess DR, a detailed fundus examination with a slit lamp biomicroscope needs to be done. Seven-standard field stereoscopic-color fundus photography needs to be done for documentation and follow-up. Patients with diabetes mellitus (DM) type 1 have a greater risk of suffering from DR. Another major complication of the condition is DME, which is characterized by an increase in the permeability of vessels and the thickening of the central part of the retina along with the accumulation of hard exudates on the macula. This article discusses various laser therapy modalities for the treatment of DR, their types, mechanisms, and aims. Clinical features of DR include abnormal dilatation of capillaries, and outpouchings in the form of microaneurysm from the capillary wall are one of the earliest and most dangerous changes; later, non-perfusion of the retina occurs, which is associated with cotton wool spots and blot hemorrhages. In patients suffering from PDR and maculopathy, peripheral retinal laser photocoagulation is used as a mode of intervention.

Three Major Causes of Metabolic Retinal Degenerations and Three Ways to Avoid Them

“…Laser photocoagulation techniques (peripheral retinal laser photocoagulation, focal macular laser photocoagulation, grid photocoagulation) offer a reliable treatment option in proliferative retinopathy, macular oedema and retinal detachment. This type of laser surgery targets the newly formed and abnormal leaking vessels [353,354]. In clinical practice, another surgical technique is vitrectomy which serves for the treatment of vitreous haemorrhages, combined/tractional retinal detachment, macular heterotopia and fibrovascular proliferations [352,355].…”

Microglia-endothelial cross-talk regulates diabetes-induced retinal vascular dysfunction through remodeling inflammatory microenvironment

“…Perivascular microglia are the unique immune cells of the central nervous system (CNS) and the retina, which play crucial roles in the maintenance of normal vascularization and participate in the inflammation responses of vascular diseases. 4 , 5 Increasing evidence has revealed that the crosstalk between microglia and ECs plays a vital role in systemic inflammation activation, blood-brain barrier (BBB) dysfunction, 6 microvascular impairment, and neuronal degeneration. 7 , 8 , 9 In the healthy tissues, microglia continuously survey their microenvironment and their activation is triggered by a great range of stimuli.…”

Beneficial Effect of Sirolimus-Pretreated Mesenchymal Stem Cell Implantation on Diabetic Retinopathy in Rats

“…These pathogenic mechanisms play a crucial role in the progression of DR. Additionally, within weeks of the onset of diabetes, leukostasis occurs in the retinal capillaries, leading to capillary occlusion and local ischemia [7]. Retinal hypoxia results in the increased expression of vascular endothelial growth factor (VEGF) [8]. Elevated levels of VEGF induce angiogenesis and enhance retinal vessel permeability, causing disruption of the barrier between the retina and blood [8,9].…”

“…Retinal hypoxia results in the increased expression of vascular endothelial growth factor (VEGF) [8]. Elevated levels of VEGF induce angiogenesis and enhance retinal vessel permeability, causing disruption of the barrier between the retina and blood [8,9].…”