Topic

#Macular Diseases

38 articles
  1. Articles 21 May 2023 9 min read

    Seven Important OCT Signs in CNVM

    1. Type of macular neovascularisation (MNV): Macular neovascularisation (MNV) is a broad disease entity characterised by the development of the abnormal vessels arising either from the retinal vasculature (deep capillary plexus) or choroidal vasculature (choriocapillaris). Choroidal neovascular membrane (CNVM) is a subtype of MNV, characterised by the abnormal growths of blood vessels from the choroidal capillaries that penetrate the retina, specifically into the sub-RPE and subretinal spaces. These vessels are extremely immature and extremely fragile, so they bleed and leak, de-structuring the macula, causing severe visual impairment. The classification of MNV is depicted below in Figure 1: Figure 1: A simple classification of macular neovascularisation (MNV): 2. Cause of CNVM: A CNVM is primarily classified based on the etiology into two categories: A) Age-related Macular Degeneration (AMD) associated CNVM and B) Non-AMD associated CNVMs. Causes of non-AMD associated CNVMs: Central s

    Dr. Ramesh Venkatesh · FVRF (Sankara Nethralaya) · +2 others
  2. Articles 13 Feb 2023 11 min read

    Optical Coherence Tomography Biomarkers in Diabetic Macular Edema

    One of the major microvascular complications of diabetes mellitus is diabetic retinopathy. Diabetic macular edema (DME) and proliferative diabetic retinopathy are the most common causes of vision loss in diabetic retinopathy. Pathogenesis of DME: A simplified understanding of the pathogenesis of DME formation is depicted in Figure 1: The role of vascular endothelial growth factor (VEGF) and inflammation in the pathogenesis of DME is depicted in Figure 2: OCT is a non-invasive imaging technique that is widely used in routine retina practice to obtain a high-definition cross section of all retinal layers and to measure their thickness. Recent advances in OCT imaging, such as the introduction of spectral-domain and swept source-based optical coherence tomography (OCT) and enhanced depth imaging, have enabled clinicians to detect and understand the various aspects of DME formation and treatment. This article will discuss the role of various OCT imaging biomarkers in identifying diabetic ma

    Dr. Ramesh Venkatesh · Aishwarya Joshi · +1 other
  3. Articles 25 Oct 2021 8 min read

    Anti-VEGFs made Easy for the Postgraduates

    The retina is a highly metabolic tissue and needs a constant high supply of oxygen. Insult to either choroidal or retinal vasculature can lead to a hypoxic state. Throughout the years, neovascularization has been seen to occur in areas neighboring such hypoxic areas. In 1989, this hypoxia-inducible and diffusible factor was discovered to be Vascular Endothelial Growth Factor (VEGF), initially coined as Vascular Permeability Factor (VPF). VEGF was found to be answerable for many types of retinopathies and the increased vascular permeability seen in them. VEGF is a heparin-binding dimeric glycoprotein with di-sulfide-linked A and B subunits. VEGF has been found to be produced by many cell types in the retina including vascular endothelial cells, retinal pigment epithelium, pericytes, Muller cells, retinal neurons, and astrocytes. It is necessary for the survival of retinal cells; prenatally for proper embryological development of the retina as well as postnatally for preserving adult mic

    Dr. Gunjan Prasai · Dr. Anadi Khatri · +1 other
  4. Articles 13 Sep 2021 30 min read

    Central Retinal Vein Occlusion: A Comprehensive Review

    Introduction: The clinical entity of Central Retinal Vein Occlusion (CRVO) has been known since 1878 (1), and it is a common visually disabling disorder that may cause significant ocular morbidity. It commonly affects men and women equally and occurs predominantly in persons over the age of 65 years (2-4). Associated systemic vascular disease, including hypertension and diabetes, are present in these population groups. The prevalence rates range from 0.1% to 0.5% in the older adult population. (3-5) Younger individuals may have an underlying hypercoagulable or inflammatory Etiology (6,7) CRVO is the second most common retinal vascular disorder after diabetic retinopathy and is considered to be an important cause of visual loss. (8) The annual risk of developing any type of retinal vascular occlusion in the fellow eye is approximately 1% per year, and it is estimated that up to 7% of persons with CRVO may develop CRVO in the fellow eye within 5 years of onset in the first eye (9-11). CR

    Dr. Priyanka Gupta · Dr. Sandeep Kumar · +1 other
  5. Articles 10 Sep 2021 10 min read

    Ten Clinical Signs A Postgraduate Must Look For While Examining the Fundus

    1. Red Dots! : Microaneurysms Seen in Diabetic Retinopathy, retinal vein occlusions, hypertensive retinopathy, radiation retinopathy. Microaneurysms are usually the first ophthalmoscopically detectable sign of diabetic retinopathy. They are focal saccular outpouchings of the capillary wall due to pericyte loss. Arise from the deep part of the inner retinal capillary plexus, and are present in the inner nuclear layer.1 Features: Appear as small round red dots - usually seen at the posterior pole, especially temporal to the fovea. 10- 100 microns in diameter. Only > 30 microns is visible ophthalmoscopically (better on red-free illumination). < 30 microns can be seen on FFA and hence more microaneurysms are seen on FFA than fundus examination. Shapes – saccular, fusiform, pedunculated, focal bulge, irregular, mixed. FFA- Hyperfluorescent with leakage. OCT – Ring sign, span more than 1 retinal layer. Course- disappear in 3-6 months. Can continue to exudate, bleed or thrombose. 2. And it wa

    Dr. Sashwanthi Mohan · Dr. Snehal Bavaskar
  6. Articles 26 Aug 2021 6 min read

    How to Quickly Read a Macular OCT Scan?

    Optical Coherence Tomography (OCT) is a quick, non-invasive, reproducible, and optical analog of ultrasound imaging which is as good as in vivo viewing of individual retinal layers histologically. In today’s practice, OCT is indisputably an essential diagnostic tool for every retinal surgeon. And so correct interpretation of OCT scans helps us in understanding the disease pathologically which in turn aids in prognosticating and making treatment decisions. How to quickly read a macular OCT? An OCT image gives you layer by layer information of retinal tissue. So if we segment the OCT image into 5 layer-wise sub-segments, it becomes very easy to read and interpret the retinal pathology. And also just by looking at the diseased/damaged retinal layer, we can identify probable clinical disease. These 5 OCT sub-segments can be used for quick interpretation of macular OCT scans. 1: VR (Vitreo-Retinal) Interface 2: Inner Retina 3: Outer retina 4: RPE/ BRUCHS MEMBRANE 5: Choroid Let us first rev

    Dr. Deepak Bhojwani
  7. Articles 17 Aug 2021 5 min read

    Ten Mistakes to Avoid while Treating a Case of Diabetic Retinopathy

    Diabetic Retinopathy is a common retinal disorder that is seen, managed, and followed up by not only a retina specialist but all ophthalmologists. It is a disease that is easy to diagnose, but often difficult to manage in a long run. For achieving optimal results besides the role of an ophthalmologist, one needs to have the involvement of a physician. The single most important factor for achieving a good outcome is patient compliance, as the disease, diabetes needs lifelong care. Here are few mistakes we need to avoid while managing a case of DR. 1. I can detect DME clinically, I don’t need OCT OCT is not mandatory if there are no signs of DR, or in very mild retinopathy (1 D, Amblyopia, Unilateral elevated intraocular pressure, Complete posterior vitreous detachment, Unilateral carotid artery stenosis, and Chorioretinal scarring 5. Ignoring a rapid progression of milder NPDR to PDR A rapidly progressive NPDR to proliferative retinopathy in a span of a few months (4-6 months) is rare a

    Dr. Rajiv Raman
  8. Articles 16 Jun 2021 14 min read

    OCT-Angiography in Retinal Diseases Made Incredibly Simple For Post Graduates

    Introduction: Optical coherence tomography angiography (OCT-A) has emerged as a novel imaging technique for visualizing the retinal and choroidal microvasculature at the macula and optic disc.1 It provides in vivo 3D vascular information by analyzing the movement of flowing red blood cells and thereby enabling the visualization and quantification of functional vessel networks within microcirculatory tissue beds in a non-invasive manner without the use of dye injection.2 Understanding the anatomy of retinal and choroidal microvasculature (figure 1): Retinal microvasculature: Studies have identified 4 retinal vascular capillary networks at the macula which are broadly grouped into 2 vascular plexuses; superficial and deep.3 The superficial vascular plexus (SVP) consists of the superficial capillary plexus and radial peripapillary capillary plexus. The former is located in the ganglion cell layer and the latter in the retinal nerve fibre layer. The SVP receives its blood supply from the c

    Dr. Ramesh Venkatesh · Dr. Nikitha Gurram Reddy · +1 other
  9. Articles 12 Apr 2021 25 min read

    Choroidal Neovascular Membrane: Made Easy For Postgraduates

    Introduction Choroidal neovascularization (CNV) or choroidal neovascular membrane (CNVM) is a growth of new choroidal vessels into the subretinal space through breaks in the Bruch's membrane. Ophthalmoscopically the CNVM appears as a greenish-grey lesion, often with a detachment of the sensory retina, subretinal blood, and exudates. Choroidal neovascularization can be multifactorial with the commonest being due to age-related macular degeneration (AMD), called the wet or exudative AMD. The other causes of include high myopia, angioid streaks, presumed ocular histoplasmosis syndrome, choroidal rupture post-trauma, osteoma, macular telangiectasia, inflammatory and idiopathic. Since the most common cause of CNVM remains age-related, this writeup will focus on the same. Age-related macular degeneration is the most common cause of blindness in the western world over the age of 65 years. With a worldwide UN estimate of about 20-25million, 8 million individuals are in the USA alone.1 The numb

    Dr. Santosh Gopi Krishna Gadde · Dr. Nikitha Reddy Gurram · +1 other
  10. Articles 2 Apr 2021 5 min read

    Intravitreal Injections -technique and tips

    Intravitreal injections involve injecting therapeutic agents (drugs/air/gases) inside the vitreous cavity through pars plana under aseptic precautions Surgical anatomy Site of injection: Pars plana Ciliary body: Consists of two parts a) anterior pars plicata b) posterior pars plana Pars plicata Circumferential zone 2.5mm in anteroposterior diameter Pars plana Varies in anteroposterior diameter nasally 3mm wide and temporally 4.5mm wide. This variation is because of the posterior globe on temporal side curves posteriorly & laterally more than on the nasal side. Pars plana extend from pars plicata anteriorly to ora serrata (termination of the retina) posteriorly. Blood vessels in pars plana are radially oriented but circumferential incisions across these vessels cause no bleeding. Also, lens zonules insert into ciliary body avoiding pars plana Thus, needle punctures 3.5 mm posterior to limbus enter globe through pars plana Not damaging lens Not puncturing the retina Not tethering / damag

    Parag K. Shah, DNB · Dr. Varsha V. Prabhu

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