Ophthalmology Board Review

Retinoblastoma

2006-06-08T06:36:00.000-07:00

Ophthalmology Question Database for Board Review

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Exam

2006-03-27T08:50:00.000-08:00

Ophthalmology Question Database for Board Review

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Keratoconus-Answers

2006-02-25T12:01:00.000-08:00

Keratoconus
Definition: Noninflammatory condition characterized by the change in eye form from normal round shape to a cone shape. Cone shape results from the bilateral central ectasia of the cornea with anterior protrusion of the cornea. Keratoconus results when the cornea thins and protrudes. Abnormal eye shape distorts visual images.
Incidence/Prevalence: Disease manifests during the late teens or early twenties, then progresses slowly for the next decade or two as the cornea scars and becomes more elongated. Although affecting both eyes, one may be more severely affected than the other. Myopia and an irregular astigmatism may result from the alteration in the normal corneal contour. Keratoconus occurs mostly as an isolated finding, but can be associated with other ocular disorders or systemic conditions (i.e. Down syndrome).
Etiology: The cause of keratoconus is unknown. Patients with the disease should avoid rubbing their eyes since it can contribute to disease progression.
Clinical Presentation: Changes in focal disruptions of the epithelial basement membrane and Bowman’s layer are initial indicators of keratoconus. Thinning of the central stroma and the anterior stroma are usually present. The Prussian blue stain (Perls test) detects iron depositions in the basal epithelial layers.

Histopathology: This macrophotograph of a bisected cornea is taken at the dissecting microscope with the cornea placed on edge. Here a brown ring called Fleisher's ring (black arrows) is evident on the surface of the cornea. At the very edge of the specimen (black arrow 1) the brown (oxidized iron) can be seen deposited within the epithelium. The white arrows show Descemet's membrane, click to enlarge. The central cornea (left side of photo) is thinner than the peripheral portion of the cornea.
Treatment: Mild cases can be treated with glasses or contact lenses. In severe cases, a corneal transplant may be recommended.

Fuch's Dystrophy-Answers

2006-02-25T11:04:00.000-08:00

Fuch's Dystrophy
Definition: Fuch's corneal endothelial dystrophy features loss of endothelium cells controlling proper endothelial pump function; thus, malfunction permits marked edema. Vision progressively becomes blurrier and more indistinct as disease advances.
Incidence/Prevalence: Fuch’s has a variable inheritance pattern and occurs more commonly in women (12.5 to 1.0 in noted family case and 4 to 1 in sporadic cases). It is one of the leading causes of bullous keratopathy.
Etiology: Fuch’s is genetically inherited from infected parents and has high pentrance as an autosomal dominant disease.
Clinical Presentation: The condition is clinically recognizable by the appearance of guttae in Descemet’s membrane. Focal, anvil-shaped outgrowths are seen buried in the thickened Descemet’s membrane. The outgrowths can also be found protruding into the anterior chamber. The appearance of endothelial cells is sparse or non-existent.
Histopathology: In this disorder the corneal epithelium episocdically separates from Bowman's layer and secondary changes occur that are featured here. The epithelial basement membrane reforms from epithelium as it reattaches leading to additional basement membrane material in the middle of the epithelium (1). The basal epithelium and sometimes the entire epithelium features a "washed out" appearance (2) which on close inspection is seen to be hydropic change. The epithelium is separated from Bowman's layer, a bullous detachment (3). Bowman's layer is irregularly thinned (arrowheads 4). The stroma is scarred as seen by irregularly contoured stromal lamellae and an uneven distribution of nuclei within the stroma (difficult to see on this PAS stain). The hallmark of Fuch's dystrophy is of course the guttata that can be seen clinically within Descemet's membrane. In this case the guttata are buried with Descemet's membrane or endophytic (5 and below 1 at the arrows). The endothelium is quite sparce but the nuclei are much better seen in a routine H&E stain.
Treatment: Palliative treatment focuses on alleviating symptoms and improving vision after epithelial edema becomes distinct. 5% NaCl drops can be used to clear the epithelial edema or increase tonicity of tear film to prevent accumulation of corneal fluid during sleep. The only real cure for Fuch’s is a cornea transplant.

Guttata may be seen clinically with retroillumination at the slit lamp (see Figure in link).

Usually, guttata in Fuch's dystrophy are exophytic as shown below.

Once again hydropic epithelial changes (1), and irregular Bowman's layer (2) , stromal scarring (3) and endophytic guttata that protrude posteriorly into the anterior chamber (4) are featured. The astute observer will notice that there is pigment in the endothelial cells.

Cornea Unknown 1 Numbered Features

2006-02-25T09:59:00.000-08:00

Click to Enlarge Image! Please identify the features that are numbered here. Link to the answers.

Cornea Unknown 1

2006-02-25T09:58:00.000-08:00

What is your diagnosis?

Bullous Keratopathy-Answers

2006-02-25T09:49:00.000-08:00

Bullous Keratopathy
Definition: Bullous keratopathy is a swelling of the cornea
Incidence/Prevalence: Bullous keratopathy is most common in older people. Bullous keratopathy occurs after cataract surgery, its incidence has decreased since the advent of intraoperative viscoelastic agents that protect the corneal endothelium and the decreased use of iris plane and anterior chamber intraocular lenses. A review at the University of Toronto indicate that pseudophakic bullous keratopathy is the 3rd leading indication of pentrating keratoplasty. (Maeno et al.)
Etiology: Often the cause of bullous keratopathy is loss of endothelium from a malpositioned intraocular lens. There is failure of the corneal endothelial cell layer to perform its normal pump function. The pumping failure can occur either because the cells themselves do not function normally or because the absolute number of endothelial cells has decreased below a critical level necessary to maintain corneal clarity.
Clinical Presentation: Bullous keratopathy occurs most commonly after cataract removal. Bullous keratopathy is characterized by the formation of fluid-filled blisters on the surface of the cornea. The blisters rupture, causing pain, often with a foreign body sensation and impairment of vision.. The diagnosis is made from the typical appearance of a swollen, cloudy cornea with blisters on the surface. Pachymetry will confirm a thicker cornea.
Histopathology: The epithelium is seen desquamating from the surface (1) or completely separating from Bowman's layer creating the bullous detachment (2). There are hydropic changes (tiny bubbles) within the epithelium giving them less apparent staining (3). Bowman's layer is irregularly thinned probably related to the bullae (4). The stroma shows areas devoid of keratocyte nuclei and irregular lamellae (5), features indicative of scarring. The endothelium is markedly attenuated; there are fewer endothelial cells than normally. Here we find only a single endothelial cell in this view (6). Additional findings that may be seen include a thickened and redundant epithelial basement membrane. There is a paucity of endothelial cells, and those cells remaining are flattened and attenuated. Descemet’s membrane is preserved intact.
Treatment: Bullous keratopathy is treated by reducing the amount of fluid in the cornea. Salty eye drops can be used to draw the fluid out. Occasionally, soft contact lenses can be used to decrease discomfort. If vision is insufficient for daily activities or discomfort is significant, corneal transplantation is indicated.

Proposed Topics and Table of Contents

2005-12-14T05:13:00.000-08:00

Ophthalmology Question Database for Board Review

Cataract & Anterior Segment

Diagnostic Tests
Anterior Segment Disorders
Types of Cataracts
Anesthesia
Infection Prophylaxis
Visco Surgical Devices
Surgery
Intraocular Lenses (IOL)
Management of Complications
Postoperative Complications

Cornea/External Disease

Diagnostic Tests
Disorders of Ocular Surface
Infections
Corneal Dystrophies
Degenerative Disorders
Immune-mediated Disorders
Neoplasms
Trauma

Glaucoma

Diagnostic Tests
Open-Angle Glaucomas
Angle-Closure Glaucomas
Medical & Surgical Treatments

Neuro-ophthalmology

Diagnostic Tests
High Intracranial Pressure
Headache
Motility Disorders
Optic Neuropathy
Pupil Disorders
Vascular Diseases

Oculoplastics and Orbit

Diagnostic Tests
Infection
Inflammatory Disorder
Diseases affecting the eyelids
Diseases affecting the orbit
Diseases affecting the nasolacrimal system

Ocular Pathology

Congenital anomalie
Conjunctiva
Cornea and sclera
Glaucoma
Inflammation
Lens
Neoplasms
Optic nerve
Orbit
Retina
Skin and lacrimal drainage system
Surgical and nonsurgical trauma
Uvea
Vitreous

Pediatric Ophthalmology and Strabismus

Diagnostic Test
Amblyopia
Esodeviations
Exodeviations
Infections
Diseases affecting the eyelids and lacrimal system
Glaucoma
Cataracts
Neoplasms
Phakomatoses
Trauma

Refractive Management and Intervention

Optics
Diagnostic Tests
Refractive errors
Contact lens
Spectacles
Refractive surgery
Vision rehabilitation

Retina and Vitreous

Diagnostic Test
Macular diseases
Disorders affecting peripheral retina
Diseases affecting the vitreous
Trauma
Tumors

Uveitis

Diagnostic Tests
Anterior Uveitis
Posterior Uveitis
AIDS
Medical Therapy

Ophthalmology Board Review

2005-12-14T05:09:00.000-08:00

Ophthalmology Board Review

Ophthalmology Question Database for Board Review

Andrew Doan, MD, PhD

Ben Glasgow, MD

Jordan Graff, MD

James Folk, MD

Andrew Lee, MD

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