Dr. Ramya Subramaniam

DNB

Darshan Eye Clinic, Chennai

2 articles

  1. Articles 20 Jul 2021 12 min read

    Pterygium: A Review

    Introduction A pterygium is a fibrovascular, wing-shaped encroachment of the conjunctiva onto the cornea, usually in the horizontal meridian of the palpebral fissure. Histopathology shows hyaline degeneration with elastotic proliferation. Risk factors Exposure to ultraviolet light and environmental microtrauma to the ocular surface is thought to predispose to pterygium formation. A localized limbal stem cell dysfunction, possibly related to ultraviolet induced damage and a genetic predisposition has also been postulated. Pathogenesis Pterygium pathogenesis can be considered as occurring in two stages: the initial disruption of the limbal corneal-conjunctival epithelial barrier, and the progressive “conjunctivalization” of the cornea characterized by cellular proliferation, inflammation, connective tissue remodeling, and angiogenesis Morphology Head—the part which rests on the cornea Neck— constricted portion seen at the limbus Body – remaining bulk of mass Cap—a semilunar infiltrating

  2. Articles 2 Apr 2021 20 min read

    Corneal Topography

    WHAT IS CORNEAL TOPOGRAPHY? Corneal topography is the study of the shape of the corneal surface. Traditionally, such measurements were limited to the near-spherical central portion of the anterior corneal surface. With the advent of corneal refractive procedures, the necessity to study the more peripheral parts of the cornea and to understand better the optics of both the anterior and posterior corneal surfaces has spawned a number of new devices that allow the clinician to better understand corneal shape, power, and optical performance. EVOLUTION OF CORNEAL TOPOGRAPHY KERATOSCOPY: It is the evaluation of the corneal surface using circular mires reflected from its surface. The earliest device designed to perform this function was the PLACIDO’S DISC, developed by Antonio Placido. It consists of equally spaced alternating black and white rings with a hole in the centre to observe the patient’s cornea. The central opening houses a convex lens for magnification and to aid the examiner’s ac