CAM I: Ophthalmology 2

CAM I: Ophthalmology 2

• Course offered by Professor Boucher at South College
• Course focus: Eye trauma, diabetic retinopathy, hypertensive retinopathy, ocular abnormalities, visual pathway, optic nerve and orbital cavity abnormalities, glaucoma, causes of blindness, cataracts, macular degeneration, chemical ocular injuries, orbital fractures, blowout fractures, retinopathy (diabetic and hypertensive), and the visual pathways.

Learning Objectives

• Recognize and explain basic types and treatment of eye trauma
• Describe etiology, signs, symptoms, and physical examination findings for diabetic retinopathy and hypertensive retinopathy
• Recognize and describe the common ocular abnormalities, including nystagmus and retinal detachment
• Describe the visual pathway
• Recognize and describe common abnormalities of the optic nerve and orbital cavity
• Describe signs, symptoms, diagnosis, and treatment of glaucoma
• Compare and contrast different diseases that may cause blindness
• Describe pathophysiology, diagnosis, signs, symptoms, and treatment of cataracts
• Describe pathophysiology, diagnosis, signs, symptoms, and treatment of macular degeneration

Eye Trauma

• Blunt or penetrating trauma to the eye (sharp object or projectile)
• Full thickness break in the eye wall (sclera and cornea)
• Requires immediate ophthalmic consultation
• Leave the eye alone after injury
• Avoid any pressure on the globe
• Avoid topical eye medications
• CT scan of orbits
• IV antibiotics (Vancomycin + Ceftazidime) typically

Open Globe/Ruptured Globe

• Blunt or penetrating trauma to the eye from a sharp object or projectile
• A full thickness break of the eye wall equals sclera and cornea
• Requires emergent ophthalmic consultation
• Do not put anything in the eye
• Apply eye shield for protection
• Avoid any pressure on the globe or eye exam procedures
• Avoid topical medications
• CT scan of orbits
• IV antibiotics per ophthalmology

Orbital Fractures

• Common in young males, typically from assault, motorcycle collision, or being struck in the face/eye
• Bones of the orbit: Frontal, Sphenoid, Zygomatic, Maxillary, and Ethmoid
• Associated structures: Frontal sinus, supraorbital nerve, Lateral canthal ligament, Inferior oblique, Inferior rectus, maxillary sinus, infraorbital nerve, Medial rectus muscle, ethmoid sinus medial canthal ligament and lacrimal duct system

Blowout Fracture

• History of small, round, high-speed object (e.g., baseball) striking the eye/orbit
• Commonly involves the inferior wall or floor of the orbit
• Symptoms include bruising, soft tissue swelling, and pain
• Diagnosed via CT imaging
• Requires ophthalmology referral and hospitalization
• Entrapment of inferior rectus muscle and/or orbital fat is a significant consequence
• Ischemia and loss of muscle function can occur due to entrapment of the muscle or edema/hemorrhage of the muscle, which has prolapsed into the maxillary sinus.

Chemical Ocular Injury

• Severe eye injury from contact with acids or alkalis
• Requires emergency evaluation and treatment to prevent permanent vision loss
• Alkaline substances cause more severe damage than acids
• Immediate referral to ophthalmology prior to leaving
• Profuse irrigation with water or saline until neutralization
• Morgan lens for continuous irrigation is common in emergency departments

Retinopathy

• Complication of hypertension (HTN) or diabetes mellitus (DM); damages blood vessels at the light-sensitive tissue (retina) at the back of the eye
• Leading cause of preventable blindness, primarily in adults 20-74 years old globally
• Symptoms include blurred vision, floaters, dark/empty vision areas, and fluctuating vision

Diabetic Retinopathy

• Microvascular complication of diabetes mellitus
• Damage to retinal blood vessels leads to retinal ischemia and edema
• Nonproliferative (early): Microaneurysms, dot and blot hemorrhages, hard exudates, and cotton-wool spots.
• Proliferative (late): Abnormal new blood vessel growth
• Importance of regular eye exams for those with risk factors

Hypertensive Retinopathy

• Related to arteriolar sclerosis and chronic high blood pressure
• Symptoms are asymptomatic, until late stages affecting vision.
• Retinal findings include copper/silver wiring, exudates (macular star), flame-shaped hemorrhages, subretinal edema, optic disc swelling, AV nicking, and cotton wool spots

The Visual Pathway

• Light follows a path from the front to the back of the eye, traveling through the cornea, aqueous humor, lens, vitreous humor to the retina
• Light is refracted by the cornea and lens
• The signal is transmitted via the optic nerve through visual pathways to the occipital lobes.

Optic Neuritis

• Acute inflammation and demyelination of the optic nerve
• Causes monocular vision loss and pain with eye movements
• Symptoms include acute onset monocular vision loss/blurred vision, along with eye pain in affected eye
• Most common cause is Multiple Sclerosis (MS)
• Diagnosis requires clinical evaluation and tests (e.g., MRI)
• Management typically involves corticosteroid treatment

Papilledema

• Swelling of the optic disc due to increased intracranial pressure
• Classically bilateral
• Symptoms can include headache, dizziness, nausea, and vomiting. Often vision loss is minimal initially
• Diagnoses through fundoscopic exam and MRI
• Treatment requires identifying and treating the underlying cause and reducing intracranial pressure

Blindness

• Common causes include cataracts, uncorrected refractive errors (presbyopia, myopia, hyperopia astigmatism), glaucoma, age-related macular degeneration, and diabetic retinopathy

Chronic Vision Loss

• Primarily in the elderly
• Major causes include glaucoma, cataracts, and age-related macular degeneration

Glaucoma

• Damage to neurons in the eye that carry vision signals to the brain due to high eye pressure.
• Often asymptomatic in its early stages
• Type categorized as chronic open-angle or acute angle-closure.
• Signs and symptoms can include high intraocular pressure, visual impairment, and halos around lights.
• Management involves early treatment with medication or surgery to control eye pressure and preserve vision.

Cataracts

• Opacity/clouding of the eye's lens
• Leads to blurry or distorted vision; painless, and progression is variable.
• Risk factors include age, smoking, alcohol, prolonged drug use (glucocorticoids, statins), HIV/AIDS, and radiation.
• Management is usually surgical removal of the cataract.

Age-Related Macular Degeneration (AMD)

• Leading cause of visual impairment in developed countries
• Two main forms: dry AMD (common, slow progression) and wet AMD (less common, faster progression)
• Risk factors include aging, smoking, and genetics
• Symptoms include gradual loss of central vision, blurry, wavy vision, difficulty reading, and driving at night.
• Screening can include use of Amsler grid test to detect abnormalities
• Management strategies include medication, smoking cessation, and lifestyle modification

Giant Cell Arteritis

• Associated with Polymyalgia Rheumatica (PMR)
• Inflammation in arteries near temples
• Risk factors include age >60-70 years
• Symptoms include new onset headache, scalp tenderness, jaw pain (claudication), fever, vision problems
• Transient or permanent vision loss are possible sequelae
• Diagnosis through studies like ESR (sed rate) and CRP blood tests
• Treatment usually involves IV steroids

Retinal Detachment

• Medical emergency where the thin layer of tissue at the back of the eye (retina) separates from its normal position
• Presentation usually involves flashes of light, floaters, sudden vision loss, and a curtain-like shadow descending over the visual field
• Risk factors include myopia, aging, family history, and previous eye surgeries
• Testing usually involves fundoscopy and ultrasound
• Treatment focuses on ophthalmological emergency surgery (e.g., pneumatic retinopexy) to reattach the retina

Retinoblastoma

• Rare malignant eye cancer in children that originates in the retina
• Family history is a significant risk factor
• Symptoms involve the absence of red reflex in the eye or the appearance of a white pupil

Visual Field Defects

• This section covers glaucoma, cataracts, age-related macular degeneration and retinal detachment and provides details for each.

9 Steps for Evaluation of the Red Eye

• Detailed step-by-step approach for examining and evaluating a red eye.
• Focuses on visual acuity, pattern of redness, presence of discharge, corneal opacities, anterior chamber assessment, pupil evaluation, response to light, presence of elevated IOP (intraocular pressure), external evaluation for infection.

Differential Diagnosis for the Eye

• Provides a structured approach to differentiate various possible causes of eye conditions based on physical signs and symptoms (e.g., trauma, keratitis, glaucoma, uveitis, lens problems, retinal detachment)

PANCE Practice Questions

• Several sample PANCE questions, covering challenging medical diagnostic scenarios in ophthalmology are presented.