Parag K. Shah

DNB

Department of Pediatric Retina & Ocular Oncology, Aravind Eye Hospital & Postgraduate Institute of Ophthalmology, Avinashi Road, Coimbatore 641014.Email: drshahpk2002@yahoo.com

5 articles

Dr. Parag K.Shah graduated in medicine from H.D.M.V.P. Samuj Medical College, Nasik, D.N.B from Aravind Eye Hospital, Madurai. After completing his residency program in Aravind Eye Hospital, Madurai he joined as a Retina Fellow at Aravind Coimbatore. Since completing his fellowship he is working as a Consultant in the Retina Department of Aravind Eye Hospital, Coimbatore and has developed the Pediatric Retina and Ocular Oncology Service. His main areas of interest are Retinopathy of Prematurity, Retinoblastoma and Intraocular tumors. He has many publications and presentations in this field.

  1. 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
  2. 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
  3. 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
  4. 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
  5. 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