Articles

91–100 of 232 articles Page 10 of 24

All Cornea 36 Cataract 17 Glaucoma 13 Retina & Vitreous 72 Neurophthalmology 8 Oculoplasty 15 Uvea & Inflammatory Diseases 24 Miscellaneous 20 Oncology 9 Pediatric Ophthalmology 15

2 Apr 2021 25 min read

Long Case of Ptosis

Blepharoptosis refers to the inferodisplacement or drooping of the upper eyelids.The condition can be congenital associated with the presence of a dystrophic levator muscle or acquired due to a myogenic, neurogenic, mechanical, aponeurotic or traumatic cause. We aim to provide certain general guidelines to the management of a patient with ptosis. In assessment of long case of ptosis the clinical examination should start with History as with any other case. History: Obtain a thorough medical and ophthalmic history. The onset of ptosis, Alleviating or aggravating factors, Family history of ptosis Whether increasing, decreasing, or constant since the time of manifestation Association with Jaw movements Abnormal ocular movements Abnormal head posture History of Trauma or previous surgery Poisoning Use of steroid drops Any reaction with anesthesia Bleeding tendency Previous photographs may prove to be of great help. Ocular Examination: Head Posture: A significant head posture (usually chin

Dr. A. K. Grover · Dr. Shaloo Bageja · +1 other
2 Apr 2021 28 min read

Medical Management of Glaucoma

Introduction The primary goal in the treatment of glaucoma is to prevent or retard the loss of visual function caused by damage to the optic nerve. Our therapeutic approaches, however, are currently limited to reducing IOP. This approach of lowering a potentially harmful pressure will apply to patients with documented optic nerve damage and visual field loss as well as those with elevated IOP or other well-described risk factors so that treatment is indicated to prevent the onset of damage. We now have five major randomized glaucoma clinical trials stating that intraocular pressure is important for protecting the susceptible optic nerve in patients with glaucoma. Basic Pharmacology Before going into the details of the drugs used in glaucoma, let us have a look at the basic pharmacologic principles in topical ocular treatment. Bioavailability of topical ocular medications: The penetration of topically applied medication into the eye is proportional to the concentration of the drug that

Dr. Rita Singh
2 Apr 2021 16 min read

Eyelid Trauma

In recent times, eyelid injuries are on the rise primarily because of the increasing incidence of road traffic accidents, industrial mishaps and intentional assaults on the human body. Injury to the eyelids, lacrimal system or orbital wall may be isolated or may occur in association with mid facial injuries. History A precise history is essential to assess the severity of the injury. In some cases, an ophthalmologist can anticipate the extent and severity of injury from the mechanism of injury. It is important to elicit the mode of injury, whether it is with sharp or blunt objects or due to thermal or chemical injury or due to dog bites. In cases of animal bites, a complete tetanus immunization history is obtained and if required proper immunization should be given. Examination Of The Patient The patient’s injury must be dealt with according to the priority. The basic “ABC’s” (Airway, Breathing, Circulation) must be evaluated, before proceeding to the management of localized injury. Th

Dr. A. K. Grover · Dr. Shaloo Bageja · +1 other
2 Apr 2021 15 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
2 Apr 2021 18 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
2 Apr 2021 22 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

Dr. Srinivas K Rao, DO DNB FRCSEd · Dr. Ramya Subramaniam, DNB
2 Apr 2021 12 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
2 Apr 2021 11 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
2 Apr 2021 14 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
2 Apr 2021 10 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