Articles

141–150 of 232 articles Page 15 of 24
  1. 1 Apr 2021 20 min read

    Fungal Endophthalmitis and it's Management

    Endophthalmitis is a potentially devastating ocular disease that may lead to permanent loss of vision. It is caused by bacteria in the majority of the cases. However, fungal endophthalmitis though rare has a poor prognosis and usually diagnosed late. The incidence of fungal endophthalmitis has increased in recent years, particularly in developing countries. 1-3 Unlike bacterial infections, we do not have much choice of medications in fungal infections. The fungus is slow-growing and we have limited choice of antifungals which act slowly. These are usually diagnosed late as patients are less symptomatic but have more signs. Moreover, fungal culture takes longer time and identification requires more expertise. Polymerase chain reaction (PCR) techniques can even detect dead remnants. Patients are usually treated as bacterial infections and would have received steroids before they are diagnosed to have fungal endophthalmitis. The prognosis of fungal endophthalmitis depends on the magnitude

  2. 1 Apr 2021 11 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

  3. 1 Apr 2021 10 min read

    Esotropia Made Simple for the Postgraduates

    As like other strabismus, esodeviation can be, True esodeviation Pseudo esodeviation A prominent epicanthic folds 1, 2 Negative angle kappa in high myopes. True esodeviation can be either comitant or incomitant 1,2 A. Comitant I. Accommodative esotropia. Refractive accommodative esotropia (normal AC/A ratio) Non Refractive accommodative esotropia (high AC/A ratio) Hypo accommodative esotropia (reduced NPA) Partially accommodative esotropia II. Non-accommodative esotropia Essential infantile esotropia Non-accommodative convergence excess Acquired esotropia Acute Onset esotropia Divergence insufficiency or paralysis Cyclic esotropia Recurrent esotropia III. Microtropia IV. Nystagmus blockade syndrome. B. Incomitant Paralytic - Neurogenic (VI nerve palsy) Nonparalytic- Myogenic (ocular myasthenia) A & V pattern syndromes Duane’s retraction syndrome Mechanical – restrictive esodeviation Congenital fibrosis syndrome Acquired Dysthyroid eye disease Trauma to the orbital wall Myositis (IOID)

  4. 1 Apr 2021 16 min read

    Herpetic Eye Disease Study: All You Should Know

    Herpes simplex virus (HSV) keratitis is the leading cause of corneal blindness in developed as well as developing countries. The ocular disease affects approximately 10 million people worldwide. Herpes viruses are a group of double-stranded DNA viruses with three subfamilies: alpha-, beta- and gamma- herpes viruses. HSV-1, HSV-2, and varicella-zoster virus (VZV) belong to the alpha-subfamily. HSV spreads by direct contact with virus shed by saliva or genital secretions. During primary infection, HSV-1 infiltrates the corneal epithelial cells. Here it lyses the host cells and releases virions which in turn infect neighboring cells. Then the HSV travels via neuronal cells to trigeminal ganglion and establishes a latent infection. HSV can remain latent for lifetime by storing its genome in the nucleus of the host neuronal cell. While latent, it produces latency-associated transcripts (LATs) that maintain the integrity of the viral genome. The latent HSV-1 can reactivate and return to the

  5. 1 Apr 2021 14 min read

    Choroidal Melanoma: Ready Reckoner for the Postgraduates

    Introduction Uveal melanoma is the most common primary intraocular malignant tumor in adults [1]. Second most common type of primary malignant melanoma after cutaneous melanoma. It arises from neuroectodermal melanocytes within the uveal tissue. Epidemiology There is strong racial variation in the incidence, with the white population most commonly affected. The mean age-adjusted incidence of uveal melanoma in the United States is 5.2 per million per year [2]. Males had a significantly higher age-adjusted incidence of 6.0 per million population compared to females, where the average age-adjusted incidence was 4.5 [3]. Malignant melanoma of the choroid is rare in dark pigmented races and has been reported infrequently in the Asian Indian population.[4] Ultraviolet (UV) radiation has been suggested as a major cause of malignant melanoma of the skin and uvea[5] because of the increased incidence and mortality among Caucasians living in tropical regions, where solar radiation is more intens

  6. 1 Apr 2021 22 min read

    Fundus Fluorescein Angiography and Indocyanine Green Angiography: Made Easy for the Postgraduates

    Introduction and Gross Anatomy: The retinal and choroidal circulatory system can be visualized in vivo in the presence of normal media clarity. Many important diseases of the retina are related to or associated with the changes in the vasculature of the retina and/or choroid. Hence, it is important to understand the circulatory systems involved to better recognize disease states of the posterior segment. The retinal and choroidal vascular anatomy can be basically divided into 3 parts: Retinal and choroidal vasculature Superficial and deep capillary plexus Inner and outer blood-retinal barriers A: Retinal and Choroidal Vasculature: The retina receives its nutrition from two discrete circulatory systems—the retinal and the choroidal blood vessels. Both are derived from the ophthalmic artery, which is the first branch of the internal carotid artery. The major branches of the ophthalmic artery are the posterior ciliary arteries, the central retinal artery, and the muscular branches. [1] Th

  7. 1 Apr 2021 15 min read

    Recurrent Corneal Erosion Syndrome - A Review

    Introduction: Recurrent corneal erosion syndrome (RCES) is a chronic, relapsing condition first described by Hansen1, who termed it as ‘‘intermittent neuralgic vesicular keratitis.’’ Stood in 1901 suggested that trauma to the corneal epithelium and anterior stroma resulted in an inability of the new epithelium to form normal attachments to the injured anterior Bowman’s layer 2. Despite more than a century of advances in corneal science, RCES remains one of the most challenging conditions to manage3. Most patients have a history of epithelial trauma or associated corneal dystrophy and respond initially to a conservative regimen of lubrication. However, they often experience frequent and debilitating recurrences. In this review, we will investigate the etiology and pathogenesis of this challenging disorder, discuss the histopathological changes with a highlight on ASOCT findings, current therapies, and present future directions for research. Etiology and epidemiology: Recurrent corneal e

  8. 1 Apr 2021 26 min read

    An Approach to a Case of Retinitis

    Inflammation of retinal tissue causes characteristic fundus findings depending on whether it is full-thickness or partial-thickness or outer or inner retinal involvement. Figure 1A: A case of epidemic retinitis: Bright yellow superficial fluffy lesion superiorly to the disc obscuring retinal vessels passing through it is typical of inner or full-thickness retinitis. 1B: A case of progressive outer retinal necrosis: Yellowish lesions with clear retinal overlying vasculature suggests outer retinitis. Full-thickness or inner retinal involvement produces bright yellow fluffy lesions with indistinct borders. (Figure 1A) Retinal vasculature passing through these lesions appears obscured. At times, such lesions can mimic cotton-wool spots and may produce moderate to severe vitritis. Outer retinal inflammatory lesions appear dull orange or yellow with indistinct borders, retinal vessels may remain clear over the lesions (Figure 1B) and vitritis could be mild-moderate. Differentiating retinitis

  9. 1 Apr 2021 43 min read

    Optical Coherence Tomography Angiography Made Simple

    Introduction Recent advances in ophthalmic imaging have opened new avenues for a more thorough and extensive understanding of various retinal diseases. Quite a few of these pathologies are attributed directly or indirectly to vascular abnormalities. This renders the need to develop technology capable of providing intricate data of the ocular vasculature. Amongst these is Optical Coherence Tomography Angiography or OCTA. It is a novel, non-invasive imaging modality which provides rapid visualization of the retinal and choroidal microcirculation. Being a dyeless procedure, it eliminates the potential side effects of conventional angiography - i.e Fundus Fluorescein Angiography (FFA)(1) and Indocyanine Green Angiography (ICGA) (2), which require an intravenous injection of a contrast agent. OCTA is a dyeless procedure OCTA derives both functional as well as structural details of the vasculature by detecting the intrinsic motion of the red blood cells within the vessels. (3) By detecting m

  10. 1 Apr 2021 9 min read

    Management of Dropped Nucleus and Retained Lens Fragment

    Introduction: Drooped nucleus and retained lens fragment is a complication not so rare in clinical practice. In the era where cataract surgery is being performed for visual enhancement rather than visual rehabilitation, the management of a dropped nucleus saves the patient from unnecessary anxiety and hastens visual recovery. In this chapter risk factors, the timing of surgery, various approaches for removal of the lens will be discussed. Incidence: Dropped nucleus and cortical remnants occur more frequently in phacoemulsification than other techniques of cataract surgery 1,2 . Surveys in developed nations like U.S and U.K have reported incidences of 0.3 % 1 and 1.1 % respectively. In India, few studies have quoted its incidence to be around 0.8 %. [3] Risk Factors: The exact cause for the posterior displacement of the nucleus is difficult to determine but certain conditions predispose for complication4 Pseudoexfoliation syndrome Traumatic cataract Fellow eye of complicated cataract su