Title: Drugs That Can Cause an Acute Angle Closure Crisis
Author: Shane Nau M.S., 4th Year Medical Student, University of Colorado School of Medicine
Figure: Nicholas Henrie, 1st Year Medical Student, University of Utah School of Medicine
Ultrasound Images: Roger Harrie, MD
Overview: Glaucoma is a type of optic neuropathy that, without proper treatment, can lead to progressive visual loss and even blindness. Though glaucoma has numerous subtypes, there are two major categories worth discussing here: Chronic Open-Angle (COAG) and Acute Angle Closure (AACG) or acute angle closure crisis. These categories can be differentiated by evaluating the iridocorneal angle, which is open in COAG but closed off or very narrow in AACG. Chronic open-angle glaucoma has an insidious onset—typically over the course of years. AACG presents abruptly and is considered an ophthalmic emergency.
Numerous medications include in their listed sided effects, “Glaucoma,” or “vision changes,” or “seeing halos or rainbows around lights.” These are most commonly referring to medications that can induce AACG or increase the risk of an individual already at risk of having such an attack. To understand why the following drugs can cause an AACG event, we must review the pathway of aqueous fluid in the eye. Aqueous fluid is produced by the ciliary body, enters the posterior chamber then moves anterior to the lens and flows through the pupil into the anterior chamber. From there it drains through the trabecular meshwork at the iridocorneal angle—where the cornea meets the iris. AT this point, the fluid moves through the trabecular meshwork to the Canal of Schlemm where it returns to venous circulation. Because the eye is continually producing aqueous fluid, the drainage pathway is critical for intraocular pressure (IOP) maintenance. Importantly, significantly elevated IOP, even for a short time, can lead to optic nerve ischemia, retinal vein thrombosis, or corneal damage. Drugs cause AACG events through two primary mechanisms: 1) Pupillary block: obstruction of aqueous flow between the lens and pupil, thereby increasing pressure in the posterior chamber, 2) Non-pupillary block: forward movement of the iris-lens diaphragm, ciliary body, or choroid. Both mechanisms result in a posterior chamber-anterior chamber pressure gradient causing anterior billowing of the iris that narrows the iridocorneal angle. The following text categorizes the medications that can induce AACG by the mechanism of angle closure (pupillary block vs. non-pupillary block) and then further by the drug class (i.e. cholinesterase).
Autonomic mechanisms of Angle Closure: The autonomic nervous system (ANS) plays a significant role in the acute closure of the iridocorneal angles. The ANS innervates, and thus, structurally and functionally affects a variety of ocular tissues. Based on the aforementioned aqueous flow pathway and anatomy, it becomes clear that structural changes within the eye that narrow the lens-iris space or iridocorneal angle can increase the likelihood of angle closure. As a reminder, the parasympathetic nervous system increases iris sphincter constriction (pupil constriction) and ciliary muscle contraction whereas the sympathetic nervous system dilates the pupil, inhibits ciliary muscle contraction, and can either increase or decrease aqueous humor production. The effects of both the sympathetic and parasympathetic nervous system vary based on the specific receptor types being acted on. For this reason, sympathomimetics, alpha-2 agonists, B-blockers, and cholinergic agonists can all be used as glaucoma medications to decrease intraocular pressure—despite their different and often antagonistic drug classes. Classically, maneuvers or pharmacological agents that cause mydriasis (a sympathetic nervous system response) are known to be a risk factor for inciting acute angle closure crises.
Drugs that cause pupillary block angle closure: Anticholinergic agents (i.e. Tropicamide eye drops, Ipratropium inhaler, Promethazine & Ranitidine-antihistamines, periocular Botulinum Toxin), drugs with anticholinergic side effects (i.e. Imipramine-other TCA’s, Fluoxetine-other SSRI’s, Fluphenazine-other antipsychotics), adrenergic agents (i.e. Phenylephrine eye drops, IV Ephedrine, Epinephrine, intranasal Naphazoline, Salbutamol), Amphetamines (i.e. MDMA, intranasal Cocaine), and Marijuana are all associated with pupillary block glaucoma. Notably, Marijuana has only been reported as an inciting agent in one patient.
Drugs that cause non-pupillary block angle closure: Cholinergic agents (i.e. Pilocarpine & Carbachol eye drops), Sulfa-based agents (i.e. Topiramate, Acetazolamide, Hydrochlorothiazide, Bactrim), Anticoagulants (i.e. Heparin), cycloplegics agents (i.e. Atropine eye drops), Dopamine receptor agonists (i.e. Cabergoline), and NSAID’s (i.e. Mefenamic Acid).
Recognition & Management: Before management of an AACG event can be initiated, clinicians must recognize its clinical features: red eye, acute-onset reduction in vision, ocular or periocular pain, headache, and colored haloes. Notable physical exam signs include: elevated IOP (>21 mmHg is abnormal, but the IOP is frequently in the 30’s or 40’s), a shallow anterior chamber, a cloudy cornea, and a pale cupped optic disc (in the case of longstanding elevated IOP). Once recognized or suspected, ophthalmology should be consulted immediately. Management focuses on decompressing the pressure gradient between the posterior and anterior chambers of the eye. This makes sense as each AACG mechanism leads to anterior billowing of the iris secondary to this pressure gradient. The specific treatment is dependent on the suspected offending drug and its associated mechanism of angle closure. Treatment options include: stopping the offending agent, administering drugs that may reverse angle closure (i.e. Miotics), reduce IOP (i.e. Beta-blockers, Alpha-adrenergic agonists, Acetazolamide, and Hyperosmotic agents), or reduce inflammation (i.e. Prednisolone), and performing a laser peripheral iridotomy—the creation of a small hole in the iris to bypass the natural aqueous flow.
Achiron A, Sharif N, Haddad F. Drug-induced Acute Angle Closure Glaucoma. American Academy of Ophthalmology, EyeWiki. June 2015. http://eyewiki.aao.org/Drug-induced_Acute_Angle_Closure_Glaucoma Accessed June 25, 2018.
Ah-kee EY, et al. A review of drug-induced acute angle closure glaucoma for non-ophthalmologists. Qatar Medical Journal. 2015; 1: 6.
Lachkar Y, Bouassida W. Drug-induced acute angle closure glaucoma. Current opinion in ophthalmology 2007; 18: 129-33
Root, Timothy. OphthoBook. Introduction to Glaucoma. https://timroot.com/glaucoma/ Accessed June 26, 2018.
Tripathi RC, Tripathi BJ, Haggerty C. Drug-induced glaucomas: mechanism and management. Drug safety 2003; 26: 749-67.
Title: Red Flag Symptoms of Unilateral Vision Loss
Author: Troy Teeples, 4th year medical student, University of Utah School of Medicine; Griffin Jardine, MD
Photographer: James Gilman, CRA, FOPS
Keywords/Main Subjects: Unilateral vision loss, monocular vision loss, red flags, headache, painful eye, pain with eye movement, floaters, flashes, atherosclerosis, central retinal artery occlusion, central retinal vein occlusion, giant cell arteritis, acute angle closure glaucoma, optic neuritis, keratitis, retinal detachment, vitreous hemorrhage, amaurosis fugax
Acute, monocular vision loss is a frightening experience for patients and may have long-term consequences depending on the etiology. The key to providing efficient, effective care is a careful history, a focused physical exam and knowing when to seek help from an ophthalmologist. The goal of this section is to help identify red flag signs and symptoms during a work up of unilateral vision loss in order to able to 1) efficiently narrow a differential diagnosis and 2) know when to urgently consult ophthalmology.
Red Flags from History and Physical Exam
There are key elements that need to be addressed when working up a patient with unilateral vision loss. Providers should look for the following associated symptoms and signs in order to guide the decision-making process.
When a patient over the age of 60 complains of a headache and unilateral vision loss, Giant Cell Arteritis (GCA) should be immediately considered given the potential for permanent vision loss. Ask the patient about a history of polymyalgia rheumatica, scalp tenderness, jaw claudication and other constitutional symptoms such as fever, malaise, weight loss or anorexia. If GCA is suspected, order an ESR, CRP and CBC looking for an elevated platelet count. If there is a high enough suspicion for GCA, don’t wait for the lab results to initiate high-dose systemic corticosteroids. An ophthalmologist should be consulted to evaluate the cause of the vision loss, specifically looking for a central retinal artery occlusion. The patient should then be schedule for a diagnostic temporal artery biopsy within the next week as an outpatient.
Red, Painful Eye
There are several causes of monocular vision loss accompanied by a red, painful eye. After inquiring about recent trauma and ruling out a ruptured globe, check the patient’s intraocular pressure (IOP) with a Tono-pen® to evaluate for Acute Angle Closure Glaucoma, as this may lead to permanent vision loss if not treated appropriately. Patients will present with a red, painful eye as well as a headache, and nausea/vomiting. They may also complain of halos around lights. Physical exam will reveal a steamy (hazy) cornea, a dilated pupil that is not reactive to light, and an IOP greater than 40 typically. Consult an ophthalmologist if suspected.
Keratitis or corneal ulcers may also present with a red, painful eye and unilateral decreased or blurry vision. Patients may complain of excessive tears or discharge, and photophobia. Ask about contact lens wear, autoimmune conditions such as rheumatoid arthritis and look for corneal whitening or loss of corneal clarity and consult an ophthalmologist if concerned.
Pain with eye movement
Optic neuritis will present with acute vision loss, typically over the course of < 1 week. The majority of these patients will have pain with eye movement and decreased color vision. They may have a history of demyelinating symptoms or a known diagnosis of multiple sclerosis. On exam, a relative afferent pupillary defect (APD) will be seen during a swinging flashlight test.
Floaters and flashes
Another combination of concerning symptoms are flashes and floaters in combination with monocular vision loss. Flashes and floaters of acute onset are concerning for a retinal detachment. Patients are commonly myopic (short-sighted) and may additionally complain of vision loss as a “curtain drawn” over their vision. A retinal detachment is painless but a surgical emergency and a vitreoretinal specialist should be consulted.
A vitreous hemorrhage may also present as painless monocular vision loss associated with floaters. Patients should be questioned regarding a history of trauma, ocular surgery, diabetes, sickle cell anemia, leukemia and high myopia, all of which may precipitate a vitreous hemorrhage.
Atherosclerosis Risk Factors
If a patient presents with painless, temporary monocular vision loss with subsequent restoration of sight, then amaurosis fugax should be high on the differential. A thorough history should include atherosclerotic risk factors such as diabetes mellitus, smoking, CAD, and HTN. Fundoscopy may reveal Hollenhorst plaques (cholesterol emboli).
Central Retinal Artery Occlusion (CRAO) and Central Retinal Vein Occlusion (CRVO) are nearly impossible to distinguish by history alone. Patients will present with acute, painless monocular vision loss without other associated symptoms. These diagnoses are made with fundoscopy revealing a “blood and thunder” appearance in CRVO along with diffuse hemorrhages and cotton wool spots (figure 1). No emergent treatment is particularly effective in reversing the changes, but there are several long-term sequelae and corresponding treatments so these patients should be referred to an ophthalmologist for close follow-up.
CRAO, on the other hand, does have a few emergent treatment options and is an ophthalmologic emergency. It can by recognized on fundoscopy by diffuse ischemic retinal whitening and a cherry red fovea along with boxcar segmentation of blood in the retinal veins (figure 2). Consult an ophthalmologist immediately if suspected and within the first several hours of the vision loss.
Images or video:
- Farris W, Waymack JR. Central Retinal Artery Occlusion. [Updated 2017 Dec 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470354/. Accessed 6/19/2018.
- Khazaeni B, Khazaeni L. Glaucoma, Acute Closed Angle. [Updated 2017 Apr 9]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430857/. Accessed 6/20/2018.
- Ness T, Bley TA, Schmidt WA, Lamprecht P. The diagnosis and treatment of giant cell arteritis. Dtsch Arztebl Int 110: 376-385, 2013.
- Patel A, Nguyen C, Lu S. Central Retinal Vein Occlusion: A Review of Current Evidence-based Treatment Options. Middle East Afr J Ophthalmol. 2016 Jan-Mar;23(1):44-8. PubMed PMID: 26957838.
Faculty Approval by: Griffin Jardine, MD
Copyright statement: Copyright Troy Teeples, ©2018. For further information regarding the rights to this collection, please visit: http://morancore.utah.edu/terms-of-use/
Title: How to Use the Direct Ophthalmoscope
Authors: Tania Padilla Conde, 4th Year Medical Student, University of South Dakota Sanford School of Medicine; Christopher Bair, MD and Michele Burrow, MD
Videographer: Ethan Peterson
LOCATION: Medical Student Education Outline > I. Introduction to the Eye Exam > Direct Ophthalmoscope > Using a Direct Ophthalmoscope – VIDEO
- Understand the utility of the direct ophthalmoscope
- Identify key anatomical structures visible with the direct ophthalmoscope
- Learn the parts and settings of the direct ophthalmoscope
- Learn the exam technique of the direct ophthalmoscope
Understand the utility of the direct ophthalmoscope
The direct ophthalmoscope allows you to look into the back of the eye to look at the health of the retina, optic nerve, vasculature and vitreous humor. This exam produces an upright image of approximately 15 times magnification.
- The Large aperture is used for a dilated pupil after administering mydriatic drops.
- The medium aperture is the standard for a non-dilated pupil in a dark room.
- The small aperture is for a constricted pupil in a well-lit room.
- Red free
- Used to look closely at the vasculature.
- Used to look for corneal abrasions or ulcers with fluorescein dye.
- Used to look at contour abnormalities of the cornea, lens or retina.
- Used to approximate the relative distance between retinal lesions.
- Wash your hands.
- Introduce yourself to the patient and explain what you are going to do.
- Position the patient so that the ophthalmoscope is held directly at the level of the patient’s eye.
- Turn on the ophthalmoscope and set the light to the correct aperture.
- Dim the lights.
- Instruct the patient to focus on an object straight ahead on the wall.
- To exam the patient’s RIGHT eye, hold the ophthalmoscope in your RIGHT hand and use your RIGHT eye to look through the instrument.
- Place your left hand on the patient’s head and place your thumb on their eyebrow.
- Hold the ophthalmoscope about 6 inches from the eye and 15 degrees to the right of the patient.
- Find the red reflex.
- Move in closer, staying nasally until you see the optic nerve.
- Rotate the diopter lens until the optic nerve comes into focus.
- The farsighted eye requires more plus/green number lenses.
- The nearsighted eye requires more minus/red number lenses.
- Measure the cup to disc ratio.
- Scan slightly up, down, right and left to look at the vessels.
- Move out temporally to find the macula and fovea.
- Repeat the same technique on the other eye.
- “Examination of the optic nerve at the slit-lamp biomicroscope with a handheld lens – EyeWiki.” Accessed July 17, 2018. http://eyewiki.aao.org/Examination_of_the_optic_nerve_at_the_slit-lamp_biomicroscope_with_a_handheld_lens
- “3.5V Standard Ophthalmoscope.” Accessed July 17, 2018. https://www.welchallyn.com/en/products/categories/physical-exam/eye-exam/ophthalmoscopes–traditional-direct/35v_standard_ophthalmoscope.html
Faculty Approval by: Griffin Jardine, MD
Copyright statement: Copyright Tania Padilla Conde, ©2018. For further information regarding the rights to this collection, please visit: URL to copyright information page on Moran CORE
Disclosure (Financial or other): None
Name: Austin D. Bohner, 2nd Year Medical Student, University of Utah, School of Medicine
Figure 1: A herpetic dendrite highlighted with a fluorescein stain.
Herpetic disease of the cornea from herpes simplex virus (HSV), also known as HSV keratitis, is a major cause of corneal scarring and blindness worldwide.1 Correct identification of HSV keratitis is important as misdiagnosis can result in a delay in treatment—or worse, inappropriate treatment with topical glucocorticoids which can exacerbate HSV infections.2
Diagnosis of HSV keratitis is based on clinical history and physical examination. Laboratory tests are usually not necessary, with slit lamp findings being typically sufficient. The exam findings include conjunctival injection near the limbus, a decrease in corneal sensation and characteristic dendritic lesions of the cornea that stain with fluorescein (see image 1).3 When deeper stromal tissue is involved corneal edema may also be found in addition to the above.
HSV-1 accounts for the majority of ocular HSV keratitis infections and is endemic in human populations, with the majority of people being exposed to the virus by middle age. The virus is transmitted through direct contact of mucosal membranes. The bulk of ocular disease is represented by reactivation of the virus from its latency in sensory neurons (usually the trigeminal nerve ganglion in ocular cases) rather than from primary infection. History of HSV infection and reactivation can be useful in making a clinical diagnosis. Most ophthalmic HSV cases occur unilaterally, with recurrences affecting the same eye. Ocular HSV reactivation has been associated with sun exposure, stress, ultraviolet laser treatment, topical ocular medication (epinephrine, beta-blockers and prostaglandins), and immunosuppression drugs such as glucocorticoids.
HSV Keratitis warrants prompt referral to an eye care specialist, as the treatment varies based on the depth of the involvement of the cornea as well as integrity of the overlying epithelium. Topical and oral antiviral medications are frequently used and can shorten the duration of the disease though each has its limitations.4
|Trifluorothymidine 1% (trifluridine, Viroptic)||One drop every two hours (8-9 doses daily)||Treatment time is limited by epithelial toxicity|
|Topical Ganciclovir 0.15% gel (Zirgan)||one drop five times daily until epithelial healing occurs and then three times daily for one week||Less corneal epithelial toxicity, maybe better tolerated for long term use compared to trifluridine|
|Topical Acyclovir 3%||Available in Europe but not in the US|
|Oral acyclovir||400mg five times daily.||Avoids epithelial toxicity, though acyclovir resistant strains of HSV exist|
- Liesegang TJ. Herpes simplex virus epidemiology and ocular importance. Cornea. 2001;20(1):1-13.
- Benz MS, Glaser JS, Davis JL. Progressive outer retinal necrosis in immunocompetent patients treated initially for optic neuropathy with systemic corticosteroids. Am J Ophthalmol. 2003;135(4):551-553.
- Teng CC. Images in clinical medicine. Corneal dendritic ulcer from herpes simplex virus infection. N Engl J Med. 2008;359(17):e22.
- A controlled trial of oral acyclovir for iridocyclitis caused by herpes simplex virus. The Herpetic Eye Disease Study Group. Arch Ophthalmol. 1996;114(9):1065-1072.
Author: DanHung Nguyen
Diplopia is commonly referred to as “double vision”, or when patients report seeing two images instead of one. The ability to fuse the two distinct images from each eye is a complex one requiring both a central or sensory component as well as a neuromuscular or motor component. What is most concerning about sudden onset diplopia is that it can be the first manifestation of a systemic, muscular, or neurological disorder.
The first step in evaluating a patient with diplopia is a thorough history, including:
- Timing of onset: Sudden onset diplopia typically warrants urgent attention, whereas insidious onset diplopia tends to be less urgent.
- Binocular or monocular: When a patient complains of diplopia, an important distinction is whether it is monocular or binocular. If the patient doesn’t know (which they tend not to), instruct them to cover up either eye and see if the diplopia resolves. If the diplopia persists while covering one eye, than it is monocular diplopia and should be specified as being left or right-sided (see attached image).
- As a general rule, there are no emergent causes of “monocular” diplopia. Monocular diplopia is often a result of an irregularity with the cornea or lens, such as dry eye, astigmatism or cataract.
- Gaze dependent: Ask the patient if the diplopia is worse or more noticeable while looking in certain directions. The direction of gaze in which the double vision is the worst helps identify the culprit extraocular muscle(s) involved.
- Vertical vs Horizontal: Next ask the patient if the images are side by side (horizontal diplopia) or one above the other (vertical diplopia).
- Trauma: Diplopia from trauma could include either cranial nerve palsies or extraocular muscle entrapment from an orbital fracture. The latter is an emergency because an entrapped muscle is pinched in a way that cuts off its blood supply and quickly becomes ischemic and fibrotic.
- Vascular Risk Factors: Ischemic cranial nerve palsies are common in older patients, especially those with multiple vascular risk factors such as diabetes, hypertension, coronary artery disease, hypercholesterolemia and a history of smoking. An isolated cranial nerve palsy in an older patient with multiple risk factors typically doesn’t require neuroimaging but simply close monitoring.
- Variability: Diplopia that varies throughout the day or from day-to-day could indicate a decompensating intermittent strabismus (esotropia/exotropia) or myasthenia gravis.
- Headache: A non-specific sign but important clue in patients older than 65 years that would require you to include Giant Cell Arteritis in your differential. It could also be a sign of an intracranial compressive mass and thus would likely warrant some form of neuroimaging.
- Ophthalmic Exam: Do a complete eye exam including the 5 ophthalmic vital signs: visual acuity, careful pupillary exam, confrontational visual fields, motility (with special attention to limited motility in the gaze that is most symptomatic to the patient) and intraocular pressure check.
- Hirschberg testing – covered elsewhere in the curriculum.
- Ptosis and anisocoria suggests a possible 3rd Nerve Palsy
- Head tilt suggests a possible 4th Nerve Palsy.
Summary of Common Causes of Sudden-Onset Diplopia
- Decompensation of pre-existing phoria
- 3rd, 4th or 6th Cranial Nerve palsy: which can be compressive (neoplastic) or ischemic (vascular or vasculitis such as Giant Cell Arteritis)
- Myasthenia gravis
- Internuclear ophthalmoplegia (suggestive of a demyelinating condition such as multiple sclerosis)
- Thyroid eye disorders
- Multiple sclerosis
- “Diplopia (Double Vision).” April 13, 2017. http://emedicine.medscape.com/article/1214490-overview.
- “Red Flags in Neuro-ophthalmology.” Accessed September 17, 2017. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5365040/.
- Root, Timothy. OphthoBook. Amazon.com, 2012.
Title: Performing the Confrontational Visual Field Exam
Author: Brian Kirk, 4th Year Medical Student, University of Utah School of Medicine
The visual field encompasses all that can be seen when fixated on a single point. This includes the central vision and the peripheral vision. There are several methods for measuring the visual field. Some common ways include using specialized instruments (i.e. Humphrey Visual Field Machine) that are capable of sensitive measurements that can detect small defects throughout the entire visual field. Another less sensitive but highly specific test is known as the confrontational visual field exam1. This is a simple and quick way to assess the peripheral vision of the patient without the use of expensive specialized equipment. It is useful as there are a variety of conditions that can affect the peripheral vision such as glaucoma, retinal detachment, stroke, vascular occlusions within the eye and certain brain tumors.
Performing the exam:
- Have the patient remove their hat or anything that could interfere with their peripheral vision.
- Sit approximately three to four feet away and directly in front of the patient. If possible, adjust your seat height until you are at eye level with the patient.
- Ask the patient to gently cover their left eye with their left hand and instruct the patient to fix their gaze directly on your left eye throughout the test.
- While the patient is focusing on your eye, close your right eye and maintain fixation on the patients open eye. Raise your hand to the inferior temporal edge of your peripheral vision halfway between yourself and the patient, while holding up 1, 2, or 5 fingers. Using only 1, 2, and 5 fingers helps to make the number more easily distinguished by the patient. Ask the patient how many fingers are seen.
- Repeat step 4, testing all four visual quadrants of the left eye: Inferior temporal, inferior nasal, superior temporal, and superior nasal.
- Repeat steps 3, 4, and 5 for the patient’s right eye.
- Johnson LN, Baloh FG. The accuracy of confrontation visual field test in comparison with automated perimetry J Natl Med Assoc. 1991 Oct; 83(10): 895–898. When compared to automated perimetry confrontational field testing was found to have an overall sensitivity of 50% and a specificity of 93.4% when examining 512 patients with both tests.
Author: Trey Winter, 1st Year Medical Student, University of Utah
Description: Scleritis is a disorder characterized by the inflammation of the sclera that can radiate to the cornea, episclera, and uveal tract. This inflammation can be destructive, painful, and potentially blinding. It is commonly associated with other systemic diseases such as rheumatoid arthritis.
Scleritis is divided into two main types, anterior scleritis and posterior scleritis. Anterior scleritis is further divided into three categories: diffuse anterior scleritis, nodular anterior scleritis, and necrotizing anterior scleritis.
Presentation: Scleritis most commonly presents with severe, constant eye pain that worsens at night and in the morning. Movement of the eye is generally painful as the muscles controlling eye movement insert into the sensitized sclera. Patients with scleritis also present with ocular redness, headaches, photophobia, and watering of the eye.
The key sign of scleritis during ocular examination is an injection (an apparent increase in size and number of blood vessels on the sclera), associated with violaceous discoloration of the eye and tenderness to palpation. Although the injection can span multiple layers, involvement of the deep episcleral vascular plexus is what distinguishes scleritis from other, less severe conditions.
Diagnosis: It is important to note that the diagnosis of scleritis involves two aspects: the primary diagnosis of scleritis and the evaluation for a systemic disorder associated with scleritis.
Scleritis can be diagnosed and classified largely based on the information in the history and from the ophthalmologic exam. The ophthalmoscopy and slit-lamp examinations are used to detect deep scleral injection. Tenderness to palpation (done by gently pressing on the eyelid over the area of inflamed sclera) is highly specific to scleritis. A less common but occult form of scleritis known as “posterior scleritis” can present with a normal appearing external eye but instead present with choroidal and posterior scleral thickening on ultrasound.
The most important differential diagnosis is between scleritis and episcleritis. Episcleritis is an inflammation limited to the episclera (the layer superficial to the sclera) and is typically not emergent or vision-threatening. Both conditions present with similar symptoms including redness of the eye and pain. The phenylephrine test can be used to help distinguish these conditions by administering phenylephrine topically to the eye. In cases of episcleritis, the phenylephrine will blanch the eye due to vasoconstriction of the episcleral vessels. The deeper and larger inflamed vessels from sclerits will remain red after administration of the phenylephrine.
A large percentage of true scleritis cases have an underlying, associated systemic inflammatory condition. Here is a truncated list with a brief review of each disease:
- Rheumatoid Arthritis: an autoimmune condition that typically effects the patient’s joints. Include a physical exam of the joints for swelling, redness or deformity. Imaging of the joints or a blood test for rheumatoid factor or inflammatory factors are used.
- Granulomatosis with Polyangiitis (Wegener’s): a condition that causes inflammation of blood vessels. Classic symptoms of Wegener’s granulomatosis include sinus pain, cough, fever, blood in the urine, and occasionally hearing loss. It can be diagnosed with a blood test for anti-neutrophil cytoplasmic antibodies (ANCAs).
- Inflammatory bowel disease (IBD): presents with abdominal pains and cramps, abnormal and sometimes bloody stools, fever, and dehydration. On physical exam, carefully check for pain in the right lower quadrant of the abdomen.
- Shingles (Herpes Zoster Ophthalmicus): is a reaction to the varicella-zoster virus (VZV) that presents in and around the eye. Diagnosis is based on an eruption of vesicles along a single dermatome that typically last a few weeks.
- Other Conditions to Consider:
- Orbital inflammatory disease
- Lymphoproliferative disorder
- Orbital abscess
Complications: Scleritis can lead to permanent ocular complications in severe cases.
Complications from scleritis include:
- Scleromalacia (scleral thinning)
- Scleromalacia perforans (scleral rupture seen with necrotizing scleritis)
- Corneal changes
- Retinal detachment
- Loss of vision
Management/Treatment: Treatment of scleritis usually begins with nonsteroidal anti-inflammatory drugs (NSAIDS), especially for diffuse anterior scleritis and nodular anterior scleritis. NSAIDS reduce the stiffness, swelling, and pain associated with scleritis. For necrotizing anterior scleritis and posterior scleritis, glucocorticoids or the combination of glucocorticoids and immunosuppressive agents are administered. In severe cases, patients need surgery to prevent rupture and retain vision.
Treatment is individualized based on the patient’s symptoms and the severity of the symptoms. As mentioned above, it is imperative not to forget a careful history and systemic work-up for any underlying, associated systemic inflammatory conditions.
- Benson WE. Posterior scleritis. Survey of Ophthalmology 1988; 5:297.
- Fong LP, Sainz de la Maza M, Rice BA, et al. Immunopathology of scleritis. Ophthalmology 1991; 98:472.
- Jabs DA, Mudun A, Dunn JP, Marsh MJ. Episcleritis and scleritis: clinical features and treatment results. Am J Ophthalmol 2000; 130:469.
- McCluskey PJ, Watson PG, Lightman S, et al. Posterior scleritis: clinical features, systemic associations, and outcome in a large series of patients. Ophthalmology 1999; 106:2380.
- Okhravi N, Odufuwa B, McCluskey P, Lightman S. Scleritis. Survey of Ophthalmology 2005; 50:351-363.
- Tuft SJ, Watson PG. Progression of scleral disease. Ophthalmology 1991; 98:467.
- Watson PG, Hayreh SS. Scleritis and episcleritis. British Journal of Ophthalmology 1976; 60:163-191.
- Albini TA, Rao NA, Smith RE. The Diagnosis and Management of Anterior Scleritis. International Ophthalmology Clinics 2005; 45:191-204.
Name and Title: Brian Walker, 4th year Medical Student, McGovern Medical School at UTHealth
Location: (Medical Student Education Outline > I. Introduction to the Eye Exam > Diagnostic use of Eye Drops > Proparacaine)
Proparacaine (Alcaine, Parcaine) is a topical ophthalmic anesthetic. This eye-drop provides 10-20 minutes of eye surface anesthesia or numbing for diagnostic and operative procedures but NEVER as a therapeutic treatment for eye pain, as repeated use can be severely toxic to the eye.
- In cases of eye pain of unknown origin, proparacaine can be used to rule out surface causes of pain (i.e. corneal or epithelial abrasion). The pain almost immediately dissipates with one drop of proparacaine.
- When combined with fluorescein, proparacaine provides numbing of a corneal abrasion while fluorescein stains the denuded epithelium.
- Proparacaine provides anesthesia for diagnostic testing that touches the surface of the eye such as tonometry and gonioscopy.
- Procedural Anesthetic
- Proparacaine is short-lasting but powerful topical anesthetic used in procedures such as intravitreal and subconjunctival medication injections, scleral depression for peripheral retinal exam, foreign body removal from the cornea and other minor ophthalmic external procedures.
- Mechanism of Action: Stabilizes the neuronal membrane by inhibiting ionic changes necessary for the initiation and propagation of nerve action potentials. Likely inhibits epithelial voltage gated sodium channels like other local anesthetics.1,2
- Onset of Action: 10-20 seconds
- Dosing: Instill 1-2 drops in the eye(s) prior to procedure, and subsequently every 5-10 minutes as needed for a maximum total of 5-7 doses.2
- Cautions: Continuous sustained use of proparacaine can result in toxic reactions to the ocular surface. The most minor include an inhibition of epithelial healing causing persistent, non-healing corneal abrasions which can results in corneal scarring and edema. The most concerning reactions include corneal stromal melting and keratopathy with the potential to result in irreversible vision loss. 3 As such, prolonged use should be avoided.
- Adverse Reactions: Contact dermatitis, hypersensitivity reaction, burning sensation of eyes, conjunctival hemorrhage, conjunctival hyperemia, corneal erosion, cycloplegia, eye redness, mydriasis, stinging of eyes.2
- Imming P., Sinning C., Meyer A. Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct; 5(10):821-34.
- Lexicomp Online®, Lexi-Drugs®, Hudson, Ohio: Lexi-Comp, Inc.; September 11, 2017.
- T., Levent T., Inci M.A. Toxic keratopathy associated with abuse of topical anesthetics and amniotic membrane transplantation for treatment. Int J Ophthalmol. 2015; 8(5): 938–944.
Author: Tanner Ferguson, 4th year medical student, University of South Dakota Sanford School of Medicine
IMAGES: Photography by James Gilman, CRA, FOPS, Moran Eye Center
Cataracts are an opacity or clouding of the crystalline lens in the eye1. Cataracts are extremely common and being able to recognize the common signs and symptoms is helpful for all clinicians. This introduction will provide a brief summary of the anatomy of the lens, risk factors for cataract formation and the symptoms associated with cataracts. For more detailed information of cataracts, please see our lens/cataract section of the CORE curriculum.
Normally, the human lens is a transparent, flexible biconcave disk that sits posterior to the iris (colored part of the eye) and is suspended circumferentially by zonular fibers from the ciliary body muscle. The lens is made up of three main parts: capsule, cortex and nucleus. The ciliary muscle contracts/relaxes to alter the shape of the lens to change its refractive power. This is particularly helpful for accommodation, or focusing on near objects, when contraction of the ciliary muscle changes the shape of the lens to bring near objects into focus. For more on accommodation, please see the Presbyopia topic (link).
The development and progression of cataract formation is dependent on numerous factors. Specific factors that can accelerate cataract formation include diabetes, steroids, trauma and intraocular surgery2,3. When cataracts do develop, patients may remain asymptomatic for some time. Symptoms typically differ depending on the type of cataract formation and its location within the lens. When they become visually significant, the common symptoms include difficulty driving at night, “starbursts” around lights, difference in color perception, cloudy vision or a change in eye glasses prescription4. Patients may even suggest their vision has improved, a phenomenon known as “second sight”, which occurs due to the change in refractive index of the lens with cataract formation5. Patients should be referred for cataract surgery when the cataract is affecting their visual needs.
Posterior Capsular Opacification
It’s also important to recognize a minor complication that many patients experience after cataract surgery. Although the capsule of the lens is typically polished and cleaned during cataract surgery, a small film can develop on the posterior capsule that is visually significant to patients, known as posterior capsular opacification (PCO). It can occur months to years after the initial procedure and is treated with an Nd:YAG laser capsulotomy, an office-based procedure.1,6 This is sometimes referred to as a “second cataract,” though this term is inaccurate as it is not a recurrence of the original cataract.
- Olson RJ, Braga-Mele R, Chen SH, et al. Cataract in the Adult Eye Preferred Practice Pattern®. Ophthalmology. 2017;124(2):P1-P119. doi:10.1016/j.ophtha.2016.09.027.
- West SK, Valmadrid CT. Epidemiology of risk factors for age-related cataract. Survey of Ophthalmology. 1995;39(4):323-334.
- Klein BE, Klein R, Lee KE, Danforth LG. Drug use and five-year incidence of age-related cataracts: The Beaver Dam Eye Study. Ophthalmology. 2001;108(9):1670-1674.
- Crabtree HL, Hildreth AJ, O’Connell JE, Phelan PS, Allen D, Gray CS. Measuring visual symptoms in British cataract patients: the cataract symptom scale. British Journal of Ophthalmology. 1999;83(5):519-523.
- Brown NA. The morphology of cataract and visual performance. Eye (Lond). 1993;7 ( Pt 1)(1):63-67. doi:10.1038/eye.1993.14.
- Fong CS-U, Mitchell P, Rochtchina E, Cugati S, Hong T, Wang JJ. Three-year incidence and factors associated with posterior capsule opacification after cataract surgery: The Australian Prospective Cataract Surgery and Age-related Macular Degeneration Study. American Journal of Ophthalmology. 2014;157(1):171-179.e171. doi:10.1016/j.ajo.2013.08.016.
Title: Ophthalmic Pathology for Medical Students
Author: Nick Mamalis, MD, Professor of Ophthalmology, Director of Ocular Pathology, Moran Eye Center
Keywords/Main Subjects: Ocular Pathology
Brief Description: A comprehensive overview of ocular pathology for medical students.
Series: Medical Student Education Outline
References: Pathologic Basis of Disease, 7th Edition, pp 1421-47.