Retina & Vitreous

41–50 of 72 articles Page 5 of 8
All Cornea 36 Cataract 17 Glaucoma 14 Retina & Vitreous 72 Neurophthalmology 8 Oculoplasty 15 Uvea & Inflammatory Diseases 24 Miscellaneous 20 Oncology 9 Pediatric Ophthalmology 16
  1. 14 min read

    Coats Disease

    Introduction History In 1908 George Coats1 original description of the disease was based primarily on histopathologic examination of enucleated eyes and identified retinal vascular aneurysms, arteriovenous malformations, intra- and subretinal hemorrhages, and exudates. Coats categorized eyes with these characteristic morphologic findings into three groups: Group I demonstrated massive subretinal exudate alone, group II consisted of eyes with massive subretinal exudate, intra and subretinal hemorrhage, and retinal vascular dilatations, and group III included eyes with subretinal exudate and retinal arteriovenous malformations. Von Hippel2 later identified group III as a separate entity, angiomatosis retinae, which led to the exclusion of this group from the spectrum of Coats disease. In 1912, Theodor Leber3 described a disorder with similar retinal vascular abnormalities to Coats disease, but without massive subretinal exudate, hemorrhage, and serous retinal detachment. This became know

    Dr. Aditya Bansal · Dr. Vikas Khetan
  2. 15 min read

    The Effects & Techniques of Scleral Buckle in Treatment of Retinal Detachment

    Introduction: Scleral buckle surgery is indicated for uncomplicated rhegmatogenous retinal detachments. Scleral buckling indents the sclera and the overlying choroid retinal pigment epithelium complex towards the retinal break in the detached retina, resulting in retinal reattachment. Scleral buckle surgery evolved out of the works of Jules Gonin, who identified retinal breaks as the cause of retinal detachment, Custodis, Lincoff and Schepens who devised ways of using an epi / intrascleral implant to “buckle” the sclera inward to create the indent.1-3 Principles of scleral buckling: The aim of scleral buckling is to close all retinal breaks to achieve permanent reattachment of the retina. General principles of retinal detachment surgery- Search for the breaks, find all the breaks, seal all the breaks, and relieve vitro retinal traction. This is achieved by - Identification of the retinal break Retinopexy – creating a sterile inflammatory reaction that would result subsequently in chori

    Dr. P. Mahesh Shanmugam · Dr. Pradeep Sagar · +3 others
  3. 26 min read

    Optical Coherence Tomography

    Introduction Optical Coherence Tomography is a powerful noninvasive imaging modality that performs high resolution, micron-scale, cross-sectional imaging of the retina. Originally developed in 1991 by Huang et al, [1] OCT technology has continually evolved and expanded within ophthalmology and has been explored in a wide range of clinical applications. With the introduction of Spectral/ Fourier Domain OCT (SD-OCT, FD-OCT) and Swept Source OCT (SS-OCT), there is greater tissue resolving power, significantly higher scan density, and faster data acquisition than original Time Domain OCT. Thus, OCT has revolutionized the practice of ophthalmology and, in particular the diagnosis and management of patients with retinal disease. This chapter describes the basics of OCT technology and its clinical applications in retinal disorders. OCT technology and working principle [2-8] OCTs operate on the principle of indirect low-coherence interferometry, in which a beam of light is directed into the re

    Dr. Remya Paulose · Dr. Jay Chhablani
  4. 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
  5. 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
  6. 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
  7. 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
  8. 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
  9. 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
  10. 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