Topic

#Vitreoretina

79 articles
  1. Students Gallery 12 Apr 2021 6 min read

    i-File: Vitreous Haemorrhage

    Question A healthy 26-year-male presented with sudden onset diminution of vision in OS of 1-week duration. The loss of vision was not associated with any trauma, pain, redness. No history of flashes. No previous history of a similar episode. On examination BCVA OD: 6/9 N6; OS: HM. Anterior segment unremarkable OU. Fundus: OD: as depicted in the fundus and FFA, OS: had a dense vitreous hemorrhage What are the differentials for the case based on the fundus picture/ Fundus Fluorescein Angiogram? How do you manage it? Answer: Let’s go in a stepwise fashion to decipher this question. The relevant points from history and FFA are The patient is young with no previous such episodes The loss of visual acuity is 1 week Although not mentioned, we presume the patient to be non-diabetic, and is not hypertensive; however, the same needs to be investigated The better eye has a large frond of NVE( neovascularization elsewhere) in the temporal quadrant So differentials in a young with dense vitreous he

    Dr. Bikramjit Pal
  2. 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
  3. 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
  4. Articles 2 Apr 2021 14 min read

    Advances in Retinal Imaging

    Modern imaging modalities in the field of the retina have expanded our understanding of common pathologies including diabetic retinopathy (DR), age-related macular degeneration (AMD), central serous chorioretinopathy (CSCR), and many rare retinal diseases such as dystrophies, which were poorly understood before. This chapter describes newer emerging techniques in retinal imaging which enables advanced screening, monitoring and provide objective measures for treatment monitoring. MULTICOLOUR IMAGING Compared to standard fundus cameras, multi-colour images produced by the scanning laser ophthalmoscope(SLO) have a higher resolution due to reduced light scatter and allow image acquisition at different planes and higher contrast through a non mydriatic pupil using different wavelengths. SPECTRALIS Optical Coherence Tomography SDOCT(SPECTRALIS SD-OCT, Heidelberg Engineering,Heidelberg, Germany) uses the confocal scanning laser ophthalmoscope(cSLO) to capture three simultaneous reflectance im

    Dr. Sushma J · Dr. Jay Chhablani
  5. Articles 2 Apr 2021 17 min read

    Primary Intraocular Lymphoma

    Introduction Intraocular lymphoma, a great non-infective masquerader occurs intraocularly in either the vitreoretinal( primary vitreoretinal lymphoma PVRL)) or in the uveal space( primary choroidal, iris lymphoma). By definition, PVRL denotes the presence of pathology limited to vitreoretinal space without its occurrence in the central nervous system. The term ‘primary’ is however controversial as almost 56-90% of PVRL patients will ultimately go on to involve the CNS over few months to years( 8-29 months) and is considered a subset of primary CNS lymphoma( PCNSL) [1]. Incidentally, 25% of patients with PCNSL will have concurrent ocular involvement at presentation [2]. Primary choroidal and iridial lymphomas are rarer, less aggressive as compared to their vitreoretinal counterpart and due to their rarity, the following section will deal primarily with PVRL. Pathophysiology of Primary Vitreoretinal Lymphoma The origin of lymphoma cells in the retina is a point of debate. Two etiologies

    Dr. Bikramjit Pal
  6. Articles 2 Apr 2021 10 min read

    Lattice degeneration of the retina

    Lattice degeneration is a vitreoretinal degenerative process of the peripheral retina with visible lesions that predispose to retinal tears and detachment. Vitreous traction at sites of significant vitreoretinal adhesion is responsible for most retinal breaks that lead to retinal detachment. GOALS of identifying the patients with risk of RD are: Identify patients at risk of RRD Examine patients with symptoms of acute PVD to detect and treat significant retinal breaks Manage patients at high risk of developing retinal detachment Educate high-risk patients about symptoms of PVD, retinal breaks, and retinal detachments and about the need for periodic follow-up. Natural history of precursors to rhegmatogenous retinal detachment Precursors to retinal detachments are PVD, symptomatic retinal breaks, asymptomatic retinal breaks, lattice degeneration, and cystic and zonular traction retinal tufts. Because spontaneous reattachment is exceedingly rare, nearly all patients with asymptomatic RRD w

    Dr. Manoj Khatri
  7. Articles 2 Apr 2021 9 min read

    Persistent Fetal Vasculature Syndrome

    It is a congenital ocular disorder where fetal vasculature persists. It can be either subtle (no disturbance in vision) or severe (profound visual loss) Anatomy 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 the iris. Posterior division has additional attachments to the cil­iary process and continues with the hyaloid artery posteriorly. Hyaloid artery: It is situated porteriorly behind the lens. It is also called primary vitreous. The hyaloid vessel extends from posterior surface of lens to the disc. The vasculature fills the vitreous cavity & has many attachments to the retinal surface Normal regression of embryonic vascular system1 During development blood flow to the eye is through hyaloid artery. At the 240-mm stage (seventh month), blood flow in the hyaloid artery ceases. Hyaloid vascular regressio

    Parag K. Shah, DNB
  8. Articles 2 Apr 2021 11 min read

    Retinopathy of Prematurity

    Introduction Retinopathy of Prematurity (ROP) is a fibrovascular proliferative disorder, which affects the developing peripheral retinal vasculature of premature infants. It is an avoidable cause of blindness in children. The initial signs of ROP are detectable by a few weeks after birth, and the condition progresses rapidly thereafter. This means that screening has to be timely, and there is only a very narrow window of opportunity for treating. If not treated, the condition progresses rapidly to Stage 4 or 5 in approximately 50% of babies. The visual prognosis for babies with Stage 5 disease (total retinal detachment) is very poor, even after complex vitreoretinal surgery. The primary goal of screening is to detect all babies with treatable disease in time for treatment to be effective. Pathogenesis In the normal foetus, vascular development of the retina occurs in two phases. Phase 1 (True vasculogenesis): It occurs from 8-21 weeks of foetal development. Spindle cells (mesenchymal p

    Parag K. Shah, DNB · Dr. V. Narendran, DNB · +1 other
  9. Articles 2 Apr 2021 8 min read

    Pan Retinal Photocoagulation (PRP), Focal Laser & Photodynamic Therapy (PDT) Technique & Tips.

    Introduction ‘LASER’ is acronym for “Light Amplification by Stimulated Emission Radiation.” This describes the emission process by which an intense beam of electromagnetic radiation is generated Basic Properties of Laser Always monochromatic (one wavelength) Collimated (all photons run parallel) & focused to a small point Coherent (always in same phase) Highest possible speed Physics Certain substances have property to lase i.e, absorb energy in one form & emit a new form of energy. On pumping these lasing substances electrons are transfered from a lower orbit to higher orbit (Bohr’s theory) Excited atoms in turn decay back to their original orbit of lower energy, emitting photons (packets of energy) This emission can be spontaneous or induced (stimulated) Photocoagulation (PHC) Photothermal reaction Temperature elevation 10 to 20 deg C Protein denaturation Pigment dependent Argon, krypton dye, diode, frequency double Nd Yag Tissue effects Induces moderate sterile inflammation- Creates

    Parag K. Shah, DNB · Dr. Varsha V. Prabhu · +1 other
  10. Interesting Reads 2 Apr 2021 11 min read

    Beginners Guide for Performing Vitrectomy

    Know your cutter and machine. Current generation vitrectomy cutters work by guillotine mechanism where vacuum holds the Vitreous fibers and presents it to guillotine blade that severs it in one swift motion without exerting significant on fibers. The cutting process needs a fine balance between the speed of cutting and the “pull” created by the vacuum. Higher cutting rates like 10000 cpm allow the surgeon to use a higher vacuum in the range of 600 mm Hg. The rate of vitreous removal also depends on duty cycle and bore size of lumen. Surgeons should test the efficiency of cutters either on cotton fibers or on the vitreous prolapsing out of sclerotomies. One has to learn to recognize when the cutter is pulling without cutting – the most dangerous situation. The surgeon should also familiarize himself with different functions of vitrectomy systems like air injection, Endodiathermy, venturi or peristaltic pumps, light source/s, Phaco Fragmatome, and Viscous fluid injection. It also helps t

    Dr. Deependra V Singh

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