Opthamology Flashcards
(36 cards)
What is the leading cause of blindness in the USA
Diabetic Retinopathy
Occurs in type 1 and type 2.
initially diabetic patients are asymptomatic despite early signs of retinopathy (micro-aneurysms).. then vision gets Progressively worse…
On opthalmoscopy will see:
- Micro-aneurysms
- Dot and blot hemorrhages
- Hard exudates
- Macular Edema
Visual impairment is caused by the development of MACULAR EDEMA.
Treatment of choice = Argon Laser Photocoagulation
Central Retinal Vein Occlusion
Characterized by SUDDEN, UNILATERAL visual impairment – usually noted upon waking up in the morning.
Painless
Diabetics are at increased risk.
Opthalmoscopy reveals:
- Disc Swelling
- Venous Dilation and Tortuosity
- Retinal Hemorrhages
- Cotton Wool Spots
Macular Degeneration
Leading cause of blindness in industrialized countries!
Characterized by DISTORTED vision (distortion of striaght lines.. appear WAVY) and central SCOTOMA (blind spot)
One of the earliest signs is straight lines appearing wavy (grid test)!
CENTRAL BLINDSPOT!!!
Progressive and BILATERAL loss of CENTRAL VISION
Peripheral fields and navigational vision are CLASSICALLY MAINTAINED
Age related macular degeneration results from degeneratino and Atrophy of the CETNRAL RETINA (macula), retinal pigment epithelium, bruchs membrane, and choriocapillaries.
The primary risk factor is increasing age.. although Cigarette smoking increases the risk of macular degeneration.
Opthalmoscopy will differentiate between the 2 types:
- Atrophic - Multiple SORES in the macular region
- Exudative - New BLOOD VESSELS that may leak, bleed, and scar the retina.
may see DRUSDEN deposits in the macula
Conversely – Open angle glaucoma presents with gradual loss of PERIPHERAL vision and consequent tunnel vision. CENTRAL VISION IS SPARED.
Retinal Detachment
occurs UNILATERALLY.
Separation of the layers of the retina.
Presents as BLURRED VISION that progressively worsens.
Opthalmoscopy - will see the RETINA hanging in the VITREOUS
“curtain coming down over eye”
Patients will complain of:
- Photopsia (flashes of light)
- Floaters (spots in the visual field)
- Grey and elevated retina on ophamoscopy
The insighting even usually occurs months before the retinal detachment - MYOPIA or TRAUMA can cause retinal breaks, through which fluid seeps in and seperates the REINAL LAYERS.
Treatment = laser therapy and cryotherapy to create permanent adhesions between the neurosensory retina, retinal pigment epithelium and choroid.
Open Angle GLaucoma
seen in diabetics
Characterized by GRADUAL loss of PERIPHERAL vision, resulting in TUNNEL VISION.
Opthalmoscopy - pathologic CUPPING of the optic disc.
Allergic Conjunctivitis vs Bacterial vs Viral
Eye involvement:
Allergic = Bilateral!
Viral and Bacterial are usually unilateral but can become Bilateral. Viral more likely to become bilateral then Bacterial.
Eye “stuck shut” in morning:
All 3 have the eye stuck shut in morning symptom.
Discharge:
Allergic and Viral = watery + scant stringy mucus.
Bacterial = PURULENT, white, yellow or green THICK mucus
Discharge Re-apperaing after wiping:
Viral and ALlergic DO NOT re-appear after wiping.
Bacterial = DOES reappear after wiping
Conjunctival Apperance:
Viral and Allergic = diffuse injection. Follicular or BUMPY apperance
Bacterial = Diffuse injection but NOT FOLLICULAR
Other symptoms:
Viral - Burning, sandy / gritty feeling, viral prodome before the eye symptoms
Bacterial = UNREMITTING OCULAR DISCHARGE
Allergic - Itching, history of allergies
Anterior Uveitis (Iritis)
Inflammation of the ANTERIOR UVEAL TRACT - especially the IRIS.
PAINFUL, RED EYE, associated with PHOTOPHOBIA, tearing and diminished visual acuity.
Not a lot of discharge
symptoms:
- significant pain
- miosis
- photophobia
- possible vision loss
HLA-B27
Orbital Cellulitis
Infection of the FAT (causing proptosis) and EXTRAOCULAR muscles (causing opthalmoplegia, painful eye movements) surrounding the eye.
this is a MEDICAL EMERGENCY
symptoms: Erythema, edema, tenderness of eyelids, often with impaired EXTRAOCULAR movement proptosis opthalmoplegia visual changes
DIagnosis is CLINICAL.. do a CT scan of orbit if diagnosis is uncertain.
Most common risk factor is sinusitis (particularly ethimoid and maxillary sinsues) / dental infection to orbit.
Treatment = IV antibiotics or surgical drainage for abcesses.
Viral Keratitis
Infection of the CORNEA related to HSV or VZV.
Patients will have corneal vesicles, opacification, and/or DENDRITIC ULCERS
Retinopathy of Prematurity (ROP)
occurs in infants born BEFORE 30 weeks (strictly).
ROP can cause retinal detachment –> resulting in Leukocoria
Leukocoria (white pupillary reflex)
As soon as you see a white reflex in a young child or infant you MUST refer to optho right away for evaluation of RETINOBLATOMA!
Retinoblastoma
Most common intraocular tumor of childhood
Will see Leukocoria (white pupillary reflex)
caused by inactivation of the tumor suppressor gene RB1.
Sporadic retinoblastoma is unilateral.. wheras inhertied retinoblastoma is usually bilateral.
Retinoblastoma is most commonly diagnosed in children under 2.. and should therefore be suspected in any child without a red reflex.
Symptoms:
- Strabismus
- Nystagmus
- Visual impairment
- Ocular inflammation
Diagnosis is confirmed with MRI of brain and orbits.
Never do a biopsy.. can cause tumor seeding.
Optic pathway glioma
NF1
Vitreous Hemorrhage
Sudden loss of vision onset of FLOATERS.
Important diagnostic clue - difficult to visualize fundus.. and if it is visualized the details of the fundus are obscured.
Most common cause is DIABETIC RETINOPATHY
Retinal Detachment
Seperation of the inner layers of the RETINA.
can be caused by diabetes, trauma, vascular disease, myopia, or degeneration.
Vision loss
Floaters
Fundoscopy - ELEVATED RETINA with folds and / or tears.
Acute Angle Closure Glaucoma Treatment
Medical Emergency! Give Narcotics to control the pain.
Angle closure glaucoma occurs with closure of a PRE-EXISTING narrow anterior chamber angle.
Presents with acute onset of SEVERE EYE PAIN and blurred vision associated with NAUSEA and VOMITING. Usually occurs following puillary dilation, which may occur in a darkened movie theater, during times of stress or due to drug intake.
Exam:
Red eye with STEAMY cornea and moderately DILATED PUPIL that is NON REACTIVE to light.
Anterior chamber is shallow, with inflmmatory changes. Increased IOP on TONOMETRY.
1st line = Mannitol - given IV, osmotic diuretic and works immediately
- Acetazolamide - carbonic anhydrase inhibitor - rapidly reduces further production of aqueous humor –> decreased IOP
- Pilocarpine - Opens canals of schlemm –> drainiage of aqueous humor (applied topically) –> rapidly reduces IOP
- Timolol - BB that decreases the IOP by decreasing production of Aqueous Humor (topical admin)
What drug should you avoid with acute angle closure glaucoma?
ATROPINE!
Anything that dilates the pupil will make Glaucoma WAY WORSE
At what age is visual acutiy testing routinely done?
Age 4.
Snellen chart is the gold standard
Trachoma
Leading cause of preventable blindness worldwide.
Caused by C. Trachomatis serotypes A,B and C.
Characterized by FOLLICULAR CONJUNCTIVITIS and PANNUS (neovascularization) formation in the cornea.
Often will have concominant nasopharyngeal infection (rhinorrhea, pharyngitis)
Repeated chornic infections cause scarring of the eyelids and INVERSION of the eyelashes (trichiasis). Over time, the lashes rub on the eye and cause ULCERATIONS and BLINDNESS (Cicatricial Trachoma)
Diagnosis is made clinically by examination of the TARSAL CONJUNCTIVAe
Treat with Oral Azithromycin
For patients with trichiasis - must have eye lid surgery
Sympathetic Opthalmia AKA Spared Eye Injury is caused by what?
Uncovering of Hidden antigens
Characterized by an IMMUNE-MEDIATED inflammation of one eye (sympathetic eye) after a penetrating injury to the OTHER EYE.
The sympathetic eye will develop ANTERIOR UVEITIS, but panuveitis, paillary edema, and blindness may develop.
Occular injury by non-caseating granulomas is seen where?
Sarcoidosis
Eye injury occurs in SLE by what mechanism?
circulating immune complexes
Postoperative Endophtalmitis
Most common form of ENDOpthalmitis
occurs within 6 weeks of surgery.
Endopthalmitis = BACTERIAL or FUNGAL infection within the eye, particularly the VITREOUS.
Patients present with PAIN and decreased visual acuity.
Examination:
- swollen eyelids and conjunctiva
- Hypopyon (cell layering within the anterior chamberO
- Corneal edema and infection
Vitreous humor can be sent for gram stain and culture.. based on severity you can do IV antibiotics or Vitrectomy.
Uveitis
caused by viral or parasitic infeciton within the eye.
Presents as blurred vision with moderate pain, conjunctival injection and CONSTRICTED PUPILS.
Hypopyon is seen in severe anteroir uveitis
Keratic precipitates (MUTTON FAT) and iris nodules can be seen.
Assoicated with HLA B-27 related conditions.
