Dr. Varsha V. Prabhu

2 articles

  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 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