Eye Pathophys Exam

Disorder Patho S/S Causes Myopia (nearsightedness) ●​ Light that comes in does not directly focus on the retina but in front of it because of a longer than usual anteroposterior diameter of the eye or steeper than average corneal curvature ●​ Distant objects are out of focus but in focus when looking at a close object Hyperopia (farsightedness) ●​ Caused by an imperfection in the eye (often when the eyeball is too short or the lens cannot become round enough), causing difficulty focusing on near objects Astigmatism (uneven refraction) ●​ May be due to an irregular curvature of the cornea or lens Presbyopia ●​ Farsightedness of old age ●​ Older fibers become displaced into the center of the lens, causing it to thicken with age ⇒ this process reduces the elasticity of the lens ●​ This effect interferes with the normal tendency of the lens to become spherical, and so diminishes the power of accommodation ●​ As a result, most persons after age 40 years begin to have difficulty reading and require correction Age-Related Macular Degeneration (ARMD) ●​ Unknown pathogenesis ●​ Predisposition is inherited in 70% of patients ●​ External factors – smoking, hydroxychloroquine use Atrophic (non-neovascular, non- exudative – dry ●​ Cellular debris called drusen accumulates between the retina and ●​ Vision is blurred due to the inability to focus on the retina ●​ Loss of central vision ●​ Central scotomas ●​ Distorted vision in the form of metamorphopsia, in which a grid of straight lines appears wavy and parts of the grid may appear blank ●​ +wavy lines ​ Exudative (neovascular) – wet ●​ Blood vessels grow between the choroid and the retina–Bruch the choroid-Bruch membrane; the retina can become detached membrane; the retina can also become detached ●​ Anti-angiogenesis inhibitors are involved in treatment​ Ectropion ●​ May occur if skin under the eye weakens ●​ Closely associated with Harlequin-type ichthyosis (severe hyperkeratosis) ●​ A condition where the eyelid (usually lower) turns out ●​ Less protection of the eye ​ Entropion ●​ Often associated with trachoma infections ●​ A condition where the eyelid (usually lower) turns in allowing the eyelashes to irritate the eye + scarring Pterygium ●​ TORCH syndrome ●​ Acronym meaning ○​ (T)oxoplasmosis ○​ (O)ther Agents ○​ (R)ubella, (German Measles) ○​ (C)ytomegalovirus ○​ (H)erpes Simplex ■​ The "other agents" included under O are Coxsackievirus, Syphilis, Varicella- Zoster Virus, HIV, and Parvovirus B19, Zika virus. ●​ Maternal infection with consequences to the developing fetus ○​ Microcephaly, fever; difficulties feeding; petechiae, hepatosplenomegaly, jaundice; hearing impairment; abnormalities of the eyes ○​ May result in unilateral or bilateral blindness, congenital cataracts or microphthalmia Down’s Syndrome Eye ●​ Brushfield’s Spots – pigment abnormalities of the iris (small white or grayish/brown spots on the periphery Deposits of fibrovascular tissue that grow in the sclera on either side of the cornea as a result of sun exposure ●​ More commonly seen with aging ●​ Generally does not impair vision Abnormalities of the iris) ●​ Eyes are tilted laterally Refractive errors and amblyopia, strabismus, nystagmus, corneal ectasias, presenile cataracts, glaucoma, and retinovascular anomalies ●​ Epicanthus – medial palpebral rim (also seen in FAS) Coloboma ●​ Slit-like defect in the iris ●​ Microphthalmia, glaucoma, nystagmus, scotoma or strabismus may also be present depending on the defect Pigmented nevus ●​ Beauty mark ●​ Malignancy potential Retinitis pigmentosa ●​ A group of inherited, degenerative eye diseases that cause severe vision impairment and often blindness ●​ Branching reticulated pattern on the retina ●​ Degeneration of rods and cones followed by migration of retinal pigment epithelial cells into the sensory retina around retinal blood vessels in the peripheral retina ●​ Vascular changes that lead to decreased retinal blood flow ●​ Night vision is often affected first!!!! ●​ No cure ○​ Vitamin A therapy may prolong the onset ofblindness Trauma Blunt ●​ Usually leads to intraocular hemorrhages ●​ Retinal hemorrhages are characteristically found in infantile abusive head trauma Superficial ●​ Minor insults of the eye surface ●​ Corneal abrasion – presents with pain, erythema, lacrimation Penetrating ●​ Punctures the globe ●​ Loss of intraocular fluid; the eye collapses; irreparable Chemical ●​ Damages the cornea and sclera ●​ Superficial ulcerations are prone to infection ●​ “Cloudy” Entropion ●​ Often associated with trachoma infections ●​ A condition where the eyelid (usually lower) turns in allowing the eyelashes to irritate the eye + scarring Viral Conjunctivitis ●​ MCC of Conjunctivitis ●​ ●​ Bacterial Conjunctivitis ●​ ●​ Purulent discharge; causing adhesions of the eyelids Trachoma Conjunctivitis ●​ C. trachomatis infection ●​ Prevalent in underdeveloped countries ●​ Major cause of blindness worldwide ●​ Spread by flies Ophthalmia Neonatorum ●​ Caused by Neisseria gonorrhoeae ●​ Infants usually become infected while passing through the birth canal of an infected mother ●​ Dacryocystitis ●​ ●​ Presents with signs of infection/inflammation along the nasal side of the eyelids S. aureus, S. pneumoniae – common pathogens Inflammation of the tear sac Erythema, watery discharge Highly contagious Severe, acute conjunctivitis with copious purulent discharge, especially in the newborn ●​ Common early cause of blindness in some parts of the world, is complicated by corneal ulceration, perforation, scarring, and panophthalmitis ​ ●​ Painful + red Stye (hordeolum) ●​ Keratitis ●​ Panophthalmitis ●​ Inflammation of the entire eye ​ Endophthalmitis ●​ Inflammation localized to the inside of the eye ​ Uveitis ●​ Inflammation of the uveal tract Iridocyclitis ●​ Inflammation involving the glands of the eyelids Develops when an infection extends into the cornea ●​ Usually caused by Herpes 1 Virus ●​ Acute onset – painful presentation ●​ Presents with pain ●​ Corneal ulcerations, scab and scar ●​ Dendritic lesions seen on slit-lamp exam with fluorescein dye Inflammation of the iris and ciliary body Onchocerciasis ●​ Onchocerca volvulus – nematode transmitted via bites on infected blackflies Prominent cause of blindness in Africa and Latin America Orbital cellulitis ●​ Bacterial cellulitis of surrounding skin ●​ Causes: Sinusitis, trauma, previous surgery ●​ Pain, erythema, edema, limited movement, vision changes, discharge, fever Dacryoadenitis ●​ Inflammation of the lacrimal GLAND ●​ Viral (mumps, EBV), bacterial (staphylococcus) ●​ Swelling, discharge, erythema, lymphadenopathy​ Type I hypersensitivity ●​ Allergic conjunctivitis – itchy ●​ Responds well to topical antihistamines and corticosteroids Type II hypersensitivity ●​ Exophthalmos ●​ May not relate to the state of thyroid function ●​ May be associated with eyelid retraction, edema of the eyelids, red eye, dry eye, chemosis (conjunctival edema), and limitation of ocular motility. ●​ Exophthalmos is part of the constellation of ocular changes known as thyroid eye disease (TED) ●​ TED is an autoimmune process in which circulating autoantibodies are thought to bind to orbital fibroblasts resulting in increased glycosaminoglycan production in the extraocular muscles ○​ Results in significant enlargement of the muscles that causes orbital congestion and, due to limited space in the orbit, pushes the eye forward​ ​ Grave’s Disease – exophthalmos Type III hypersensitivity ●​ Involve the ciliary body or choroid ●​ Occasionally seen in patients with SLE Type IV hypersensitivity ●​ ●​ ●​ ●​ Granulomas of the eye – rare Sarcoidosis – presents as granulomas of the lacrimal glands Crohn’s Disease – uveitis, episcleritis RA – episcleritis, keratoconjunctivitis sicca (severe dryness) ⇒ Any autoimmune Circulatory Disorders ●​ The thin, delicate vasculature is subject to damage ○​ Grade III-IV hypertensive retinopathy is a marker of hypertensive emergency ●​ Hypertensive Retinopathy ○​ Damage to the retinal and chordial blood vessels ○​ Reactive narrowing – associated with arteriosclerosis ■​ Copper wire (early); silver wire (late) ○​ Microaneurysms and hemorrhages ■​ Dot and flame-shaped hemorrhages ○​ Exudates with elevated pressure ■​ Hard and soft exudates, macular star, cotton-wool spots ○​ Arteriovenous nicking – tortuous, kinked veins ○​ Hypertensive emergency – necrotizing arteriolitis with fibrinoid necrosis, thrombosis ●​ Sickle cell disease ○​ Intraretinal occlusion, hemorrhages, retinal detachment Optic Nerve Disease ●​ Papilledema ○​ Edema of the optic disk due to increased intracranial pressure (most common), obstruction to venous drainage of the eye, infarction of the optic nerve, optic neuritis, and multiple sclerosis ●​ Optic atrophy ○​ Thinning of the optic nerve caused by loss of axons ○​ Etiology – long-standing edema of the optic nerve head, optic neuritis, optic nerve compression glaucoma, retinal degeneration Diabetic Ophthalmopathy ●​ Major cause of blindness in the US ●​ Cataracts and diabetic retinopathy are most common ●​ Diabetic Retinopathy ○​ 2 types: background (non-proliferative), proliferative ○​ Both are related to changes in the basement membrane of the arterioles and capillaries of the choroid and retina ○​ Pathophysiology – Background retinopathy ■​ Diabetic blood vessels are more permeable, which leads to edema, lipoprotein exudate accumulation and hemorrhage ■​ Ischemia (secondary to vascular changes) results in degeneration and fibrous deposits ■​ Cotton wool spots, fibrous streaks, microaneurysms, neovascularization ○​ Pathophysiology - proliferative retinopathy ■​ Generally, develops after many years of DM retinopathy (NP) ■​ Reperfusion of ischemic area by neovascularization along with fibrous and glial tissue grow toward the vitreous body ■​ Closely associated with the degree of glucose control ■​ The proliferating fibrovascular and glial tissue contracts, potentially causing a traction retinal detachment and blindness ●​ Blindness ○​ DM involved ophthalmopathy is the leading cause of blindness (ages 20-74) in the US Non-arteritic Anterior Ischemic Optic Neuropathy ●​ Idiopathic ischemic insult of the optic nerve ○​ Results from a circulatory insufficiency, or infarct, within the retrolaminar portion of the optic nerve head that is supplied by the short posterior ciliary arteries ○​ Characterized by acute, monocular, painless visual loss with optic disc swelling ○​ “lacunar stroke” of the optic nerve ●​ May be seen with overtreatment of hypertensive emergency ○​ Initial treatment should not lower SBP more than 25% of baseline by end of first day (to prevent NAION, MI, stroke) ●​ Risk factors ○​ Atherosclerosis, nocturnal hypotension, sleep apnea, renal failure, any prothrombotic risk factor, ESRD Temporal Arteritis ●​ “Giant cell arteritis” ○​ Pathophysiology: Systemic inflammatory vasculitis of medium and large-sized arteries (temporal arteries) ■​ Dysregulated response to vascular injury – CD4+ cells, IL, IFN mediated ■​ “giant cells” – macrophage syncytia ○​ ○​ ○​ ○​ Leads to ischemic optic neuropathy with vison loss Other arteries can be involved: aorta, subclavian, iliac, occipital Commonly associated with polymyalgia rheumatica S/S ■​ Fever, HA, vision changes, jaw pain Optic Neuritis ●​ Inflammation of the optic nerve ●​ S/S ○​ Sudden loss of vision, blurred vision, pain, erythema of the eye ●​ Causes ○​ Multiple sclerosis - most common etiology ■​ 50% of patients with MS will develop an episode of optic neuritis ■​ 20-30% optic neuritis is the presenting sign of MS ○​ Infection ■​ syphilis, Lyme disease, herpes zoster ○​ autoimmune disorders ■​ SLE, IBD ○​ Medication induced ■​ chloramphenicol, ethambutol ○​ vasculitis, B12 deficiency and diabetes Retinal Disease ●​ Retinal detachment ○​ The retina detaches from underlying connective tissue ○​ Medical emergency; permanent damage will result w/in 24-36 hours w/o treatment ■​ Presents with sudden loss of vision – usually with half of the visual field lost ○​ S/S ■​ preceded by a posterior vitreous detachment with the following symptomatology ■​ photopsia – in the peripheral part of vision ■​ a sudden dramatic increase in the number of floaters ■​ a ring of floaters or hairs just to the temporal side of the central vision ○​ Causes ■​ Cataract surgery, eclampsia, malignant hypertension, retinoblastoma, severe myopia, smoking and passive smoking, Von Hippel-Lindau disease, trauma, DM, ocular melanoma, sickle cell disease, retinal deformity ●​ Amaurosis fugax ○​ Temporary loss of vision due to lack of blood flow to the retina ○​ Transient blindness ○​ Commonly related to cardiovascular disease (stroke) Retinal Hemorrhage ●​ May occur with local and systemic disease ●​ Causes HTN, DM, retinal vein occlusion bleeding diatheses, trauma ●​ Appearance of the hemorrhage varies with cause and location ○​ Nerve fiber layer – flame-shaped appearance on fundoscopy ○​ Deep retinal hemorrhage – round, dot or blot appearance ○​ Between the vitreous face and retina (preretinal) – bright red round or boat-shaped appearance Retinal Occlusive Vascular Disease ●​ Blood supply of the retina ○​ Retinal blood vessels and posterior ciliary blood vessels ●​ Vascular occlusion results from thrombosis, embolism, stenosis, vascular compression, and vasoconstriction ●​ Retinal ischemia leads to fluffy white patches (cotton-wool spots) on exam ○​ Cotton-wool spots consist of swollen axons in the nerve fiber layer of the retina containing numerous degenerated mitochondria and lysosomes, which accumulate because of impaired axonic flow ●​ Central retinal artery occlusion ○​ Seen more commonly in atherosclerosis, giant cell arteritis, or embolization to that vessel ○​ Retinal thickening and pallor are prominent due to intracellular edema ○​ The fovea stands out as a prominent cherry-red spot because of the underlying vascularized choroid ​ Glaucoma ●​ Characterized by increased IOP leading to atrophy of the optic nerve > 21 mmHg ○​ Increased IOP is not seen in all cases of glaucoma – optic neuropathy is present ○​ The cup-to-disc ratio (CDR) is a measurement to assess the progression of glaucoma ○​ As glaucoma advances, the cup enlarges until it occupies most of the disc area ●​ Aqueous humor - clear, low-protein fluid ○​ Fills the anterior chamber ○​ Helps maintain the internal pressure; prevents it from collapsing ○​ Provides nutrients; mediates the exchange of respiratory gases ○​ Drains into episcleral veins via the trabecular meshwork ●​ Loss of peripheral and central visual fields ●​ Affects 1-3% of patients > 40 yo ○​ Black race > 40 yo; White race > 65 yo ●​ Early diagnosis and treatment can prevent progression and damage ●​ Pathophysiology ○​ Primary – no apparent underlying cause ○​ Secondary – related to a pre-existing condition ■​ Iridocyclitis, intraocular hemorrhage, trauma, tumors ○​ As IOP rises the canal of Schlemm is compressed – further reducing the flow of aqueous humor ○​ Aqueous humor is reabsorbed into the venous circulation ○​ The secretory activity of the ciliary epithelium requires the enzyme carbonic anhydrase ○​ Production of aqueous humor should equal amount of drainage ○​ Accumulation of aqueous humor increase IOP ●​ Primary – open vs. closed angle ○​ Open angle ■​ Most common, etiology unknown ■​ Insidious onset, slowly progressing ■​ If left untreated optic nerve damage, retinal atrophy, and blindness result ■​ Bilateral presentation with one eye usually affected to a greater degree ○​ Closed angle ■​ Visible obstruction of the angle ■​ Often presents with acute onset of intraocular pain, loss of vision, and erythema ■​ Intraocular pressure is elevated only during attacks ■​ May be seen more often in patients with long-standing hyperopia (farsightedness) ●​ The iris is displaced forward to narrow the angle at the anterior chamber, obstructing flow of aqueous humor Cataracts ●​ An opacification of the crystalline lens ○​ Lens material degenerates which exerts osmotic pressure ■​ Allowing for swelling and displacement of the iris with narrowing of the anterior chamber ○​ Patients complain of blurry vision ●​ The most common cause of decreased vision in the US ●​ Classification ○​ Congenital ○​ Senile cataracts ■​ Most common form - 60% of all people > 70 yo ■​ Considered a disease of aging that has no obvious cause except wear and tear ○​ Secondary cataracts ■​ Consequence of trauma, inflammation, corticosteroids or radiation ●​ DM predisposes individuals to cataracts ○​ The increased sorbitol content of the lenses causes imbibition of water and enlargement of the lens ●​ Most people develop some clouding of the lens after the age of 60 Neoplasm ●​ Retinoblastoma & malignant melanoma - most common tumors of the eye ●​ Retinoblastoma ○​ Rare tumor ○​ Seen in infancy and childhood ○​ 15% of cases are hereditary ■​ Retinoblastoma suppressor gene ■​ The first identified TSG ○​ Grows as an intraocular mass that fills the entire globe and extends into the optic nerve ○​ Clinically recognized as a white pupil ■​ Presents with leukocoria (white reflection from the retina) and absence of red reflex (indicates an opacity of the cornea) ○​ 90% survival rate ■​ LT survivors are at risk for developing other neoplasms, most commonly osteosarcoma ●​ Malignant Melanoma ○​ Most common primary intraocular tumor affecting adults ○​ Tumors originate from the pigment cells of the uveal tract (iris, ciliary body or choroid) ○​ 2 types ■​ Spindle cells ■​ Tend to grow slowly and are amenable to local resection ■​ Non-spindle cells ■​ Less favorable outcome ○​ Complications include retinal detachment, chordial hemorrhage, macular edema ○​ The liver is a common site for mets Chalazion/Strabismus ●​ Chalazion ○​ Aka meibomian gland lipogranuloma ■​ Cyst in the eyelid caused by inflammation of a blocked meibomian gland ■​ Usually on the upper eyelid. ■​ Meibomian gland – sebaceous gland on the rim of the eyelid ■​ Subacute and usually painless nodules (differing from hordeolum) ●​ Strabismus – “Squint” “lazy eye” ○​ Heteropia ■​ Eyes point in different directions ■​ Esotropia ■​ Exotropia Hyphema/Nystagmus ●​ Hyphemia (hyphema) ○​ Blood in the anterior chamber of the eye ○​ Causes ■​ Infection, trauma, retinoblastoma, drugs (warfarin, aspirin), eye surgery ●​ Nystagmus ○​ Rapid, involuntary eye movement ○​ Types ■​ Manifest nystagmus – always present ■​ Congenital nystagmus ■​ Manifest-latent nystagmus – always present, but worsens when one eye is covered ■​ Acquired nystagmus ■​ Latent nystagmus – present when one eye is covered Dry Eye Syndrome ●​ Associated conditions ○​ Aging ○​ Sjögren syndrome ○​ Rheumatoid arthritis ○​ Stevens-Johnson syndrome ○​ Systemic medications: antihistamines, diuretics, antidepressants ●​ Symptoms ○​ Burning, foreign body sensation, grittiness, tearing ●​ Complex physiology involving disruption of the tear film Otitis Externa ●​ Susceptible to any skin disease ●​ Otitis Externa – “swimmer’s ear” ○​ Bacterial (pseudomonas), viral, fungal etiologies ○​ Pain with movement of the pinna ○​ TM is difficult to see ○​ Necrotizing otitis externa ■​ Seen in DM, immunocompromised ■​ Hospitalization for IV abx – antipseudomonal ■​ Granulation tissue present ○​ Otomycosis ■​ Pruritis > otalgia ■​ White or black fluffy infiltrates ○​ Herpes vesicles on the external ear canal ■​ May lead to nerve damage and hearing loss Diseases of External Ear ●​ Cauliflower Ear ○​ Caused by major laceration or repeated hematoma ●​ Allergic Otitis Externa ○​ Most often found in children with atopic dermatitis (eczema) ●​ Contact Dermatitis ○​ Hypersensitivity to earrings, hearing aids ●​ Malignancies ○​ Squamous cell, basal cell, melanoma Diseases of the Middle Ear ●​ Perforation of the tympanic membrane ○​ Most important consequence of middle ear trauma ○​ Small defects usually heal spontaneously ●​ Otitis media ○​ Acute ■​ Bacterial or viral etiology ■​ S. pneumoniae, H. influenza, M. catarrhalis ■​ Edema, erythema (+/-), bulging, opaque membrane, fluid accumulation (purulent with bacterial infections), pain, hearing loss ■​ Typanocentesis – may be indicated in resistant infection – culture and sensitivity ■​ Complications – chronic otitis media, extension of infection to the mastoid, inner ear, brain ■​ More common in children, males, bottle-fed infants, homes where smoking occurs, children in daycare, pacifier use ■​ Effusion – blocked feeling; bubbles in effusion; fluid can last for up to 3 months ○​ Chronic ■​ Consequence of recurrent acute infections ■​ Characteristic chronic purulent discharge, pain, loss of hearing ○​ Myringotomy tubes ■​ Current guidelines for American otolaryngologists indicate tube placement in the following conditions: ■​ Chronic otitis media with persistent effusion for 6 months (one ear) or 3 months (both ears). ■​ Recurrent acute otitis media: 3 ear infections in 6 months or 4 infections in a year. ■​ Persistent eustachian tube dysfunction ■​ Barotrauma: Especially for prevention of recurrent episodes (e.g., after air travel, hypobaric chamber treatment). ■​ Tubes generally remain in the eardrum for 6 months to 2 years ●​ Cholesteatoma ○​ An epidermal inclusion cyst ○​ Common complication of chronic OM ○​ Tumor-like growth (benign) ■​ Grows from the auditory canal through the tympanic membrane and into surrounding bone ■​ Pearly-white in appearance ●​ Glue Ear ○​ A form of non-bacterial chronic otitis media ○​ Characterized by a persistent viscous effusion ○​ Treatment (if persisting > 3 months is placement of myringotomy tubes) ●​ Otosclerosis ○​ The most common cause of conduction hearing loss in middle-aged Americans ○​ Unknown etiology ○​ Inherited as an autosomal dominant trait ○​ 2x more common in women ○​ Bilateral presentation ○​ Characterized by deposition of newly formed bone in the oval window (located between the semicircular canals and cochlea) ○​ Treatment involves removal of the sclerotic bones and replacement by a plastic prosthesis Diseases of the Inner Ear ●​ Meniere Disease ○​ Unknown etiology; peak onset 30-60 yo ○​ Associated with hydrops (fluid accumulation) of the endolymphatic system of the cochlea ○​ Clinical presentation triad ■​ Episodic vertigo that last 1+ hours ■​ Sensorineural hearing loss for low frequency sound ■​ Tinnitus ○​ Diagnosis of exclusion –R/O ■​ Viral labryinthitis – following an upper respiratory tract infection ■​ Post-traumatic vertigo – typically a consequence of head trauma ■​ Vertigo related to migraine HA ■​ Central vertigo related to brain disease – tumors, MS, stroke ○​ Treatment includes low sodium diet, diuretics, antiemetics, anti-vertigo medications ●​ Acoustic neuroma ○​ Benign primary intracranial tumor of Schwann cells of the vestibulocochlear nerve ○​ Slow growing tumors ○​ S/S ■​ Tinnitus, deafness, vertigo ●​ Labyrinthitis ○​ Inflammation of the vestibular system structures of the ear ○​ Most often caused by a viral or bacterial infection following a URI ○​ S/S ■​ Vertigo, nystagmus, hearing loss ●​ Mastoiditis ○​ Inflammation/infection of the mastoid process of the temporal bone ○​ Often causes by extension of an otitis media ■​ Upper respiratory tract pathogens ○​ S/S ■​ Pain, tenderness, erythema in the mastoid region ○​ Complicated by movement of infection to surrounding structures ■​ Difficult for abx penetration ■​ Deafness, brain abscess, labyrinthitis Hearing Loss ●​ Classification ○​ Conductive Hearing Loss ■​ External or middle ear lesions ■​ Causes ■​ Obstruction, impacted cerumen, tympanic membrane loss, effusion, cholesteatoma, hemorrhage, otosclerosis ■​ Associated with bone conduction greater than air conduction and sound lateralizing to the affected ear ○​ Sensory Hearing Loss ■​ Results from cochlear abnormalities ■​ Causes ■​ Noise trauma, ototoxic drugs ○​ Neural Hearing Loss ■​ Results from lesions of cranial nerve VIII (vestibulocochlear) ■​ Least common form of hearing loss ■​ Typical causes include neuromas, MS, CVA