Block 7 Ophtho Flashcards
Cataract
Degradation of optical quality of crystalline lens
Nuclear cataract: central opacification; progress slowly; affect distance vision
Cortical cataract: central or peripheral; symptom is glare
Posterior subcapsular cataract: visual impairment if affect axial region of lens; in younger patients; symptoms are glare and poor vision with bright light; near vision more affected
Mixed cataract: predominant type; some of many types
Treatment of cataract
Once vision starts declining, no chance of recovery unless there is surgical intervention
Glaucoma
Damage to the optic nerve in a characteristic pattern
Usually associated with increased intraocular pressure (IOP)
Open angle (no symptoms until vision loss) or closed angle (halos around lights, blurry vision, pain, headache)
Treatment of glaucoma
No cure at this time
Goal is to lower eye pressure
Medications, laser surgery or incisional surgery
Age-related macular degeneration
Gradual destruction of macula (central part of retina) causing central vision loss
Usually in people age 50 and older
Risk factors: smoking, caucasian, family history (genetic risk)
Diagnosed with dilated eye exam
Symptoms: early on no symptoms, then difficulty adjusting to lights at night, distortion of central vision, late symptoms are blurred central vision then central dark spot
Symptoms are gradual for dry form and sudden/rapid for wet form
Dry vs. Wet AMD
Either form can cause severe vision loss
Almost all who have wet form had dry form first
Dry: 90% (more common), slow break down of cells in macula slowly blurs central vision, drusen (yellow deposits under retina), pigment disturbances, pigment epithelial detachments, geographic atrophy
Wet: 10%, advanced AMD, when new blood vessels under macula leak blood and fluid (choroidal neovascular membranes cause disciform scars), treat with drug injections, photodynamic therapy, laser therapy
Thyroid eye disease (TED)
AKA Grave’s ophthalmopathy, Grave’s orbitopathy, Dysthyroid orbitopathy, Thyroid-associated orbital disease
Autoimmune inflammatory disease
2 phases: active/dynamic and static/inactive
Clinical diagnosis
Thyroid function may be normal, hyper or hypo (TED can arise before or after thyroid disease manifests)
Severe effects on visual function (5% go blind), appearance: proptosis, periorbital swelling, double vision, sight threatening (corneal ulceration, compressive optic neuropathy), fibrosis
Treatment: corticosteroids (oral or injection)
Staged surgical management of TED
1) Orbital decompression: remove bone and fat from behind eye or medial wall of orbit
2) Extraocular muscle surgery: remove muscle then suture back together
3) Eyelid repositioning
4) Soft tissue redraping: cosmetic rejuvenation
Diabetic retinopathy
With Type I, get DR 3-5 years after onset of DM
With Type II, get vision loss/DR as presenting symptom
Long term hyperglycemia is a cause
HTN is risk factor
Pathophysiology of blood vessel disease: microaneurysms, capillary BM thickening, neovascularization, VEGF
Macular edema, central macular ischemia, proliferative DR (treat with panretinal photocoagulation)
Summary: poor glycemic control –> capillary occlusion/permeability –> retinal ischemia –> increased VEGF –> vitreous hemorrhage, traction retinal detachment lead to vision loss; macular edema due to VEGF causes vision loss too
Eye examination for diabetes
Type I: get first eye exam 5 years after onset; yearly follow-up
Type II: get eye exam at time of diagnosis; yearly follow-up
During pregnancy w/diabetes: get eye exam before pregnancy for counseling then early in first trimester, then each trimester or even more frequently; 3-6 months post partum follow-up
Eye disease and syphilis
Interstitial keratitis
Uveitis: anterior uveitis and subretinal plaques
Jarisch-Herxheimer reaction: inflammation after beginning antibiotics when spirochetes are dying
Argyll-Robertson pupil
Eye disease and gonorrhea
Natural pathogen means can affect mucus membrane even when epithelium is intact (goes thru intact epithelial barriers)
Copious purulent discharge
Requires systemic treatment
Inclusion conjunctivitis
Chlamydia trachomatis serotypes D-K
Always associated with GU infection
Requires systemic treatment
HLA-B27 acute anterior uveitis (AAU)
Most common intraocular inflammation (uveitis)
Sudden onset, one eye, lasts 1 month but is recurrent
Gut disease (mucosal): subclinical colitis
Vitamin A deficiency
Vitamin A needed for absorption of light (rhodopsin)
Mutations in genes for enzymes cause some forms of retinitis pigmentosa
Night blindness (nyctalopia)
Dry eye (bitots spots, corneal damage, secondary infection)
