Topic

#Vitreoretina

79 articles
  1. Articles 1 Apr 2021 18 min read

    Angioid Streaks

    Angioid streaks are visible irregular crack-like dehiscences in Bruch’s membrane that are associated with atrophic degeneration of the overlying retinal pigmented epithelium. Despite 50 % of cases being idiopathic, this condition grabs attention as it requires good history taking and workup to determine the cause. Historical background The first description of angioid streaks was provided in 1889 by Dr. Robert W. Doyne, an English ophthalmologist. He noticed irregular, jagged deeply pigmented lines especially around the discs of both eyes in a patient who sustained trauma in both eyes and attributed it to be due to the rupture of pigment layer of retina. [1] Because of their resemblance to blood vessels, Herman J. Knapp, a German-born American ophthalmologist coined and introduced the term "angioid streaks" in 1892. [2] They are also known as Knapp’s striae. Clinical examination with histopathological findings by Bock in 1938 in two patients with pseudoxanthoma elasticum confirmed that

    Dr. Remya Paulose · Dr. Bhavik Panchal · +1 other
  2. Articles 1 Apr 2021 15 min read

    Paediatric Retinal Vascular Diseases

    Introduction This chapter will discuss pediatric retinal vascular diseases like Persistent Fetal Vasculature, Familial Exudative Vitreo Retinopathy and Incontinentia Pigmenti Persistent Fetal Vasculature (Persistent Hyperplastic Primary Vitreous) Definition Persistent hyperplastic primary vitreous (PHPV) is a congenital ocular disorder in which fetal vasculature does not regress after birth. It is unilateral approximately 90% of the time. No single gene has been identified. It can vary from very subtle with no visual disturbance to as severe as phthisis bulbi or secondary glaucoma. The prognosis can be good if early intervention is planned. Due to its wide spectrum of presentation, it has now been renamed as persistent fetal vasculature (PFV).1 Pathogenesis The fetal vasculature is composed of two parts: Tunica vasculosa lentis. It is situated anteriorly encircling the lens. It has anterior and posterior divisions. Anteri­or division has additional attachments to the pupillary frill of

    Parag K. Shah, DNB · Dr. V. R. Saravanan · +1 other
  3. Articles 1 Apr 2021 20 min read

    Fungal Endophthalmitis and it's Management

    Endophthalmitis is a potentially devastating ocular disease that may lead to permanent loss of vision. It is caused by bacteria in the majority of the cases. However, fungal endophthalmitis though rare has a poor prognosis and usually diagnosed late. The incidence of fungal endophthalmitis has increased in recent years, particularly in developing countries. 1-3 Unlike bacterial infections, we do not have much choice of medications in fungal infections. The fungus is slow-growing and we have limited choice of antifungals which act slowly. These are usually diagnosed late as patients are less symptomatic but have more signs. Moreover, fungal culture takes longer time and identification requires more expertise. Polymerase chain reaction (PCR) techniques can even detect dead remnants. Patients are usually treated as bacterial infections and would have received steroids before they are diagnosed to have fungal endophthalmitis. The prognosis of fungal endophthalmitis depends on the magnitude

    Dr. Sugandha Goel · Dr. Ekta Rishi
  4. Interesting Reads 1 Apr 2021 10 min read

    Ten Things You Should Know about 3D Viewing System in Ophthalmology

    1. Evolution of this latest state of the art technology in ophthalmology: Three-dimensional (3D) display systems were first developed for aircraft and military use. The term “heads-up surgery” derived from the so-called “head-up display”, a display system first used in aircraft flight decks that projects an image into the normal field of view. This display system allows visualization in a “heads-up” position. In this procedure, the operating surgeon does not perform by looking at the eyepieces of the microscope, but by viewing the microscopic image on a panel display sent from a 3D camera[1]. After the creation of the TrueVision 3D Visualization System for Microsurgery, this innovative, ground-breaking technological boon has entered the operating room. 2. Major types of 3D visualization technique: Conventional 3D systems are classified as either active or passive systems. In active systems, the 3D image is obtained by showing high-speed consecutive images for the right and left eyes al

    Dr. Aniruddha Maiti, MBBS, DO, DNB, MNAMS,FRVS, FICO, MRCSED(Ophth) · Dr. Joydeep Majumdar, MBBS,DNB
  5. Articles 1 Apr 2021 13 min read

    Choroidal Melanoma: Ready Reckoner for the Postgraduates

    Introduction Uveal melanoma is the most common primary intraocular malignant tumor in adults [1]. Second most common type of primary malignant melanoma after cutaneous melanoma. It arises from neuroectodermal melanocytes within the uveal tissue. Epidemiology There is strong racial variation in the incidence, with the white population most commonly affected. The mean age-adjusted incidence of uveal melanoma in the United States is 5.2 per million per year [2]. Males had a significantly higher age-adjusted incidence of 6.0 per million population compared to females, where the average age-adjusted incidence was 4.5 [3]. Malignant melanoma of the choroid is rare in dark pigmented races and has been reported infrequently in the Asian Indian population.[4] Ultraviolet (UV) radiation has been suggested as a major cause of malignant melanoma of the skin and uvea[5] because of the increased incidence and mortality among Caucasians living in tropical regions, where solar radiation is more intens

    Dr. Isha Agarwal · Dr. Vikas Khetan
  6. Articles 1 Apr 2021 17 min read

    Fundus Fluorescein Angiography and Indocyanine Green Angiography: Made Easy for the Postgraduates

    Introduction and Gross Anatomy: The retinal and choroidal circulatory system can be visualized in vivo in the presence of normal media clarity. Many important diseases of the retina are related to or associated with the changes in the vasculature of the retina and/or choroid. Hence, it is important to understand the circulatory systems involved to better recognize disease states of the posterior segment. The retinal and choroidal vascular anatomy can be basically divided into 3 parts: Retinal and choroidal vasculature Superficial and deep capillary plexus Inner and outer blood-retinal barriers A: Retinal and Choroidal Vasculature: The retina receives its nutrition from two discrete circulatory systems—the retinal and the choroidal blood vessels. Both are derived from the ophthalmic artery, which is the first branch of the internal carotid artery. The major branches of the ophthalmic artery are the posterior ciliary arteries, the central retinal artery, and the muscular branches. [1] Th

    Dr. Ramesh Venkatesh · Dr. Sajjan Sangai · +1 other
  7. Articles 1 Apr 2021 42 min read

    Optical Coherence Tomography Angiography Made Simple

    Introduction Recent advances in ophthalmic imaging have opened new avenues for a more thorough and extensive understanding of various retinal diseases. Quite a few of these pathologies are attributed directly or indirectly to vascular abnormalities. This renders the need to develop technology capable of providing intricate data of the ocular vasculature. Amongst these is Optical Coherence Tomography Angiography or OCTA. It is a novel, non-invasive imaging modality which provides rapid visualization of the retinal and choroidal microcirculation. Being a dyeless procedure, it eliminates the potential side effects of conventional angiography - i.e Fundus Fluorescein Angiography (FFA)(1) and Indocyanine Green Angiography (ICGA) (2), which require an intravenous injection of a contrast agent. OCTA is a dyeless procedure OCTA derives both functional as well as structural details of the vasculature by detecting the intrinsic motion of the red blood cells within the vessels. (3) By detecting m

    Dr. Nasiq Hasan · Dr. Manasi Tripathi · +1 other
  8. Articles 1 Apr 2021 9 min read

    Management of Dropped Nucleus and Retained Lens Fragment

    Introduction: Drooped nucleus and retained lens fragment is a complication not so rare in clinical practice. In the era where cataract surgery is being performed for visual enhancement rather than visual rehabilitation, the management of a dropped nucleus saves the patient from unnecessary anxiety and hastens visual recovery. In this chapter risk factors, the timing of surgery, various approaches for removal of the lens will be discussed. Incidence: Dropped nucleus and cortical remnants occur more frequently in phacoemulsification than other techniques of cataract surgery 1,2 . Surveys in developed nations like U.S and U.K have reported incidences of 0.3 % 1 and 1.1 % respectively. In India, few studies have quoted its incidence to be around 0.8 %. [3] Risk Factors: The exact cause for the posterior displacement of the nucleus is difficult to determine but certain conditions predispose for complication4 Pseudoexfoliation syndrome Traumatic cataract Fellow eye of complicated cataract su

    Dr. Dhanashree Ratra · Vineet Ratra · +1 other
  9. Articles 1 Apr 2021 14 min read

    Ultrasound B-Scan: A Ready Reckoner for the Postgraduates

    The importance of ultrasound imaging cannot be stressed upon more than the fact that whether you are an anterior segment surgeon, posterior segment surgeon or oculoplastic surgeon, the indications for this modality transcend across all genres of ophthalmology. Many a time, postgraduates find this topic daunting to interpret. This article aims to simplify Ultrasound B-scan in terms of mechanics, terminology, actual procedure, and interpretation without delving deep into the confusing jargon. Some common conditions and their typical presentations will also be touched upon. For ease of understanding, we will divide this article into the following sections: History Basic physics and instrumentation Terminology Indications Examination techniques: basic and special Features of commonly encountered posterior segment conditions History Though the concept of ultrasound waves was known to humans in the 18th century (Lazzaro Spallanzini’s observation on the use of ‘sound whistles’ by bats in dark

    Dr. Anmol Naik · Dr. Shveta Gadewar · +1 other
  10. Articles 1 Apr 2021 19 min read

    A (VAST)IN Saga

    Vascular endothelial growth factor (VEGF)-A is a key mediator of angiogenesis. The discovery of VEGF-A, like many other major discoveries in medicine, happened partly by observations and partly by chance. Napoleone Ferrara and his team were working on a population of non-hormone-secreting cells from the anterior pituitary of cows. (1) One day Ferrara mixed some isolates from cultures of follicular cells with endothelial cells. Ferrara was surprised to see the rapidly proliferating endothelial cells started rapidly. Ferrara understood that the pituitary cells were secreting an angiogenic protein. With this observation, Ferrara worked on the isolation and cloning of this angiogenic protein. In 1989, Napoleone Ferrara and Hazel at Genentech laboratory were the first to isolate and clone vascular endothelial growth factor (VEGF). Ferrara recalls, “I worked on the isolation of VEGF in my spare time during my first six months to a year at Genentech. Once we cloned VEGF in 1989, the company b

    Dr. Bikramjit Pal · Dr. Parthopratim Dutta Majumder

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