Cornea

11–20 of 36 articles Page 2 of 4
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
  1. 25 May 2021 9 min read

    Seven Tips to Treat A Treatment Resistant Microbial keratitis

    Microbial keratitis is a common potentially sight-threatening condition and is considered an ocular emergency. Managing them brings forth multiple challenges to the ophthalmologist one of them being to primarily distinguish an infective from non-infective keratitis. Based on signs, symptoms, history, and laboratory investigations a treatment plan is laid out which is modified based on clinical response and antimicrobial sensitivity. However, if the response to treatment is inadequate or the microbial keratitis is resistant to treatment it becomes mandatory to assess the factors causing it and change the therapeutic strategy accordingly. The present article attempts to look at the different factors which cause resistant microbial keratitis and means to manage them. Both local/ocular and systemic factors can contribute to the resistant nature of the ulcer and are listed in table 1. The need to address systemic concerns with the help of a physician along with the ocular factors cannot be

    Dr. Shweta Agarwal · Dr. Bhaskar Srinivasan · +1 other
  2. 5 May 2021 23 min read

    Simple Limbal Epithelial Transplantation: A Review

    I. Introduction The cornea is lined by non-keratinized, stratified squamous epithelium. At the limbus, there is a gradual transition of these cells to non-keratinized, stratified columnar epithelial cells, along with mucin-secreting goblet cells, forming the conjunctival epithelium. The corneoscleral limbus lies between these two epithelia in a healthy eye. The limbus contains palisades of Vogt, the basal layer of which function as a repository for the corneal epithelial stem cells.(1, 2) These limbal epithelial stem cells (LESC’s) divide whenever the corneal epithelium is required to be replenished. As the stem cells divide, one of the daughter cells retains the primitive nature of the parent cell and functions to maintain the stem cell pool. The other daughter stem cell differentiates to acquire the physiological nature of a specific tissue, like the corneal epithelium. These cells are known as ‘transient amplifying cells’, which then divide and migrate centripetally, circumferential

    Dr. Supriya Sharma · Dr. Swapna Shanbhag · +1 other
  3. 2 Apr 2021 16 min read

    Allergic Eye Diseases

    Introduction Allergic eye disease (AED) is a common problem, owing to the fact that the eye is the first organ to encounter environmental allergens. It has been reported to affect 20% of the population worldwide1, 2. Allergic eye disease is found to be on the rise in line with other atopic diseases like asthma, due to environmental reasons. Classification of Allergic Eye Diseases 1, 4 1. Allergic conjunctivitis Acute allergic conjunctivitis Seasonal allergic conjunctivitis Toxic induced (acute contact with irritant) Chronic allergic conjunctivitis Perennial allergic conjunctivitis Toxic induced (long standing) 2. Contact dermatoblepharitis 3. Vernal keratoconjunctivitis 4. Atopic keratoconjunctivitis 5. Giant papillary conjunctivitis 6. Microbial allergic conjunctivitis Staphylococcal blepharoconjunctivitis Phylectenular keratoconjunctivitis Splendore Hoeppli phenomenon (allergic granulomatous Nodules) Immunopathology in allergic eye disease 3, 5 The ocular surface exhibits a variety o

    Dr. P.Vijayalakshmi
  4. 2 Apr 2021 16 min read

    Peripheral Ulcerative Keratitis

    Peripheral ulcerative keratitis (PUK) is a form of ocular inflammation that involves the peripheral portion of cornea and may be associated with systemic conditions such as Rheumatoid Arthritis(RA), Wegener’s Granulomatosis(WG), and other systemic conditions. It is a potentially devastating disorder consisting of a crescent-shaped destructive inflammation at the margin of corneal stroma that is associated with an epithelial defect, presence of stromal inflammatory cells, and progressive stromal degradation and thinning. The onset of Peripheral Ulcerative Keratitis has been linked to various anatomical factors of central and peripheral cornea and adjoining limbus. Though the local concentration of small and medium weight proteins like IgA, IgG and most complements are similar in central and peripheral cornea, the peripheral cornea has been found to be associated with higher concentrations of higher molecular weight(HMW) protein molecules like IgM and complement C1(5 times), possibily ow

    Dr. A. Agarwal, MD · Dr. A.Panda, MD, FAMS, FICS, FICO, MRC Ophthalmology
  5. 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

    Dr. Srinivas K Rao, DO DNB FRCSEd · Dr. Ramya Subramaniam, DNB
  6. 2 Apr 2021 10 min read

    Chemical Injuries of Eye - An Update.

    Introduction It is very frequent to encounter chemical injury in our routine ophthalmic practice. Most of the chemical injuries are minor, which heal without any squeal. Most are acids and alkalis. Alkali injuries are more common (nearly twice) than acids and are more severe in nature. It is of utmost importance to recognize the nature of chemicals for treating such patients. Here, we review the chemical injuries of the eye with their recent management update. Epidemiology Chemical burn 7.9-9% of all reported ocular burns. 23 -42% are bilateral. Young males are affected mostly. Most are industrial accidents (at workplace 60-70%, at homes 25-30%, criminal assault, and others comprise 2-3%) Sources of common chemicals Alkalis Acids 1.Ammonium hydroxide and Ammonia- fertilizers, laboratory refrigerator, household cleansing agent, bleaching powder 2. Sodium hydroxide-drain cleaner, soap 3. Potassium hydroxide- soap 3.Calcium hydroxide- plaster, cement, mortar, whitewash(chuna) 4.Magnesium

    Dr. Sushobhan Dasgupta · Dr. Tarannum Shakeel · +1 other
  7. 1 Apr 2021 10 min read

    Cornea Edema : Ready Reckoner for the Post Graduates

    Corneal edema is defined as the increase in the thickness of cornea due to the accumulation of extracellular fluid in epithelium and stroma resulting in loss of corneal transparency. Pathophysiology: Cornea remains in a relatively dehydrated state maintaining a 78% hydration level. Corneal hydration depends on 5 factors. 1. Stromal swelling pressure (SP) This is the tendency of stroma to swell due to interfibrillary proteoglycans and other proteins. The normal stromal pressure is 55mmHg. Imbibition pressure (IP) – It is a negative pressure exerted by glycosaminoglycans by which fluid is drawn into the cornea. Intraocular pressure (IOP) = SP + IP 2. Barrier function The epithelium (Zonula occludens tight junction) offers twice the resistance to water flow compared to the endothelium (macula occludens tight junction) and the electrolyte resistance is 200 times higher in the epithelium than endothelium.1 3. Endothelial pump The endothelium pump function ensures, through active transport,

    Dr. Sumana Chatterjee
  8. 1 Apr 2021 20 min read

    Acanthamoeba Keratitis: A review for the Postgraduates

    Eye diseases affecting the cornea are a major cause of blindness worldwide. Among different infectious agents, bacteria, fungi, viruses and protozoans may be causes of keratitis. This article is about the keratitis caused by protozoa. Three amoebic parasites are thought to be significant to human disease, entamoeba which is responsible for amoebic dysenter, naegleria which causes amoebic meningoencephalitis and acanthamoeba which is known for causing keratitis and granulomatous amoebic encephalitis. Acanthamoeba is a ubiquitous, free living protozoa of the subphyla Sarcodina. It is considered as opportunistic pathogen in humans. Acanthamoeba keratitis is a potentially devastating corneal infection which can lead to severe visual loss. Epidemiology: Acanthamoeba keratitis (AK), is rare in the general population (estimated incidence: 1.4 per million person- year) but much frequent in contact lens wearers. The incidence of the disease in developed countries is approximately 1-33 cases per

    Dr. Hema Joshi, MBBS, DO, DNB
  9. 1 Apr 2021 39 min read

    Fungal Keratitis: A Review for the Post-Graduates

    Introduction Fungal or mycotic keratitis is a leading cause of ocular morbidity, opacification and preventable blindness.1 The approximate annual incidence of fungal keratitis in India is said to be 11.3/10,000 population.2 Frequently it is caused by filamentous fungi (Aspergillus, Fusarium, Curvularia) in the tropical areas, while in temperate regions it is predominantly caused by Candida species (C. albicans, C. Parapsilosis). It is considered as one of the most difficult forms of microbial keratitis for the Ophthalmologist to diagnose and manage. Medical therapy alone is often inadequate and surgical therapy like therapeutic penetrating keratoplasty, conjunctival flap, lamellar keratoplasty or cryotherapy is required for control of infection. Epidemiology and Demographics Fungal keratitis incidence or prevalence is more in tropical regions of the world like India and Southern USA and is less commonly encountered in the temperate zones.3 In East India, fungal keratitis was found to b

    Dr. Ankit Anil Harwani · Dr. Meena Lakshmipathy
  10. 1 Apr 2021 10 min read

    Ten Pearls for Descemet's Membrane Detachment Repair

    1. Embryology Understanding the embryological development of the cornea helps us appreciate the reasons for a Descemet's membrane (DM) detachment during surgery. After the lens vesicle separates from the surface epithelium, a wave of mesenchyme forms the primary corneal stroma. A second wave then forms the endothelium, which secretes the DM. The DM, hence, has a potential plane of separation from the corneal stroma, which we use to our benefit in DMEK surgery and which works against us in an inadvertent DM detachment. Throughout the life of an individual, the DM thickens as the posterior non-banded layer is secreted by the endothelium. The anterior fetal banded layer tends to remain the same. However, in most instances, the separation happens between the DM and the cornea stroma1. The thickness of the DM varies between 10 and 15 microns, increasing with age. DM does not regenerate after any damage2. 2. Cataract Surgery and DM Detachment A post-cataract DM detachment occurs in 0.26% of

    Dr. Amanda Mohanan · Dr. Sanjeev P Srinivas · +1 other