ophthalmology II Flashcards
What is near-sightedness due to
Near-sightedness occurs when the optical power of the eye is too large and causes light to focus in front of the retina
what is far sightedness due to
Far-sightedness occurs when the optical power of the eye is too small and causes light to focus behind the retina
what is astigmatism
Astigmatism describes the shape of the cornea and causes light to focus in front or behind the retina.
presbyopia
another form of refractive error however it results when the eye progressively losses its ability to focus on near objects. It is a symptom caused by natural aging as the lens becomes less flexible. Usually first occurs around 40-50 yrs. The ability to focus on near objects continues to decline throughout our lives
how is visual acuity tested
Standard Snellen Eye chart. Stand 20 ft away and measure one eye at a time, with glasses (or pinhole)
How are visual fields measured
Have patient look at your nose and cover one eye. Hold fingers in periphery at ask how many fingers present. Then repeat for other eye.
how is ocular motility measured
follow finger left, right, up and down
how are pupils tested
Are they round, reactive to light, equal,
how is external eye exam performed
use pen light to observe eyelids, conjunctiva, cornea and anterior chamber
What is the fundoscopic exam
using hand held ophthalmoscope, check red reflex, optic nerve and retina
causes of unilateral red eye
Viral or Bacterial Conjunctivitis, Iritis, Corneal Abrasion, Corneal Ulcer, Herpes Simplex, Herpes Zoster Ophthalmicus, Subconjunctival Hemorrhage
causes of bilateral red eye
dry eyes or allergic conjunctivitis
most common viral cause of conjunctivitis
adenovirus- or after respiratory tract infection
most common cause of bacterial conjunctivitis
staph aureus and strep peumoniae.
compare presentation of bacterial vs viral conjunctivitis
bacterial has more inflammation of conjunctiva. Viral appears more red. Bacterial will have thick, purulent discharge and eyelid can appear more swollen and almost closed
treatment of bacterial conjunctivits
eyedrops- Preferably 3rd or 4th generation fluoroquinolone (Ciloxan, Ocuflox, Zymaxid or Vigamox), Sulfacetamide or Tobramycin. Gentamicin drops can be toxic and cause irritation with prolonged use.
symptoms of iritis
ocular or periorbital eye pain, photophobia, blurred or cloudy vision, redness (near limbus), irregular shaped pupil
Iritis treatment
Topical Steroid Eye Drops (Pred-Forte), Dilating Eye Drops (help prevent synechiae within the eye and with pain), Occasionally Topical Glaucoma Drops
Causes of recurrent iritis
Ankylosing Spondylitis, Rheumatoid Arthritis, Behcet’s Disease, Crohn’s Disease, Ulcerative Colitis Lupus, Sarcoidosis, Syphilis, TB
Corneal abrasion - symptoms and diagnosis
severe eye pain or foreign body sensation with acute onset, tearing, blurred vision and redness. Can use fluorescein stain with blue light to see epithelial defect
corneal abrasions- treatment
milde: artificial tears and topical antibiotic. Large: antibiotic ointment and patching of eye, or contact lens. NO topical anesthetic eye drops b/c they delay healing
corneal ulcer- what is it, what causes it
Corneal ulcer is an infection of the corneal stroma.
Causes include bacterial (Staph aureus, Pseudomonas), fungal (Fusarium) and protozoa (Acanthamoeba). Caused by trauma with vegetative matter (fungal), contact lens wear (bacterial or protozoa) and risk 10 x higher for extended wear, dry eye, facial nerve paralysis.Corneal ulcer is an infection of the corneal stroma.
Causes include bacterial (Staph aureus, Pseudomonas), fungal (Fusarium) and protozoa (Acanthamoeba). Caused by trauma with vegetative matter (fungal), contact lens wear (bacterial or protozoa) and risk 10 x higher for extended wear, dry eye, facial nerve paralysis.
Corneal ulcer- symptoms
Acute onset with severe pain, redness, decrease in vision, eyelid swelling. White infiltrate in cornea, thinning of cornea at infiltrate, hypopyon inside anterior chamber.
corneal ulcer treatment
small: hourly trtmt with 4th generation fluoroquinolone. Large: require culture to determine the organism. Done with a calgi swab and placed on blood agar, Chocolate and Sabouraud’s plates. Also require fortified antibiotics including vancomycin and tobramycin. Slow healing and can leave scar with vision loss. Corneal transplant if risk of perforation
small: hourly trtmt with 4th generation fluoroquinolone. Large: require culture to determine the organism. Done with a calgi swab and placed on blood agar, Chocolate and Sabouraud’s plates. Also require fortified antibiotics including vancomycin and tobramycin. Slow healing and can leave scar with vision loss. Corneal transplant if risk of perforation
how are corneal foreign bodies removed
A majority of the time if the object has been present for a couple days a rust ring may develop. Needs to be removed with a diamond burr.
What is dry eye -symptoms
Dry eyes is a common disorder of the tear film. Symptoms include foreign body sensation, blurred vision, reflex tearing. Condition worsens towards end of the day and activities that require attention – reading, computer work. Environmental influences
Causes of dry eye
Systemic Conditions: rheumatoid arthritis, lupus, Grave’s disease. Medications: anti-histamines, pain medication, anti-depressants. Environmental
Dry eye diagnosis and treatment
Schirmers test and corneal staining patter. Artificial tears, Flax seed oil, Omega-3 vitamins. Medicated eye drops to help improve tear production (restasis). Modification of oral medications, treatment of any underlying systemic disease, Punctal plugs
allergic conjunctivitis treatment
v Avoidance of the offending allergen Topical antihistamines (Zaditor, Naphcon-A) Topical mast cell stabilizers/antihistamines (Patanol, Bepreve, Elestat) Topical steroids (FML, Pred-Forte) v Avoidance of the offending allergen Topical antihistamines (Zaditor, Naphcon-A) Topical mast cell stabilizers/antihistamines (Patanol, Bepreve, Elestat) Topical steroids (FML, Pred-Forte)
How does herpes simplex affect eye
Herpetic keratitis- red eye. Primarily from HSV-1 infection of corneal epithelium. unilateral eye redness (can be bilateral), pain, photophobia, decreased vision, and tearing
Herpetic keratitis- diagnosis and treatment
Fluorescein on the ocular surface shows dendritic epithelial ulcer in branching pattern with terminal bulbs. Most cases will resolve spontaneously within three weeks. Medication can shorten the duration.
Topical trifluridine Q2H. Oral acyclovir 400mg 5x/day or valacyclovir 1g TID. May develop scar after healing causing blurred vision
Fluorescein on the ocular surface shows dendritic epithelial ulcer in branching pattern with terminal bulbs. Most cases will resolve spontaneously within three weeks. Medication can shorten the duration.
Topical trifluridine Q2H. Oral acyclovir 400mg 5x/day or valacyclovir 1g TID. May develop scar after healing causing blurred vision
Herpes zoster ophthalmicus- cuase, symptoms
reactivation of VZV. Dermatological involvement of V1 distribution. Symptoms include prodromal period of fatigue, low-grade fever, unilateral rash on forehead, upper eyelid and nose. Ocular manifestations more likely if Hutchnison sign (lesion on nose) b/c both are innervated by nasociliary nerve.
Herpes zoster ophthalmicus- treatment
oral acyclovir, oral valacyclovir. May develop chronic dry eye and infections
What is pterygium
Benign fibrocascular tumor, UV induced. Often becomes inflammed. Treatment: Artificial tears, Sunglasses, Vasoconstrictors (short-term). Conjunctival Autograft with Tissel glue.
angle closure glaucoma- symptoms, exam, treatment
Symptoms include unilateral severe eye pain, nausea, redness, blurred vision and halos around lights. Examination may show sluggish, mid-dilated pupil, conjunctival injection, hazy cornea and shallow anterior chamber. When palpating the eye it may feel hard. treatment: laseral peripheral iridotomy
open angle glaucoma- cause, risk factors, symptoms
Progressive disease of the optic nerve that is often associated with elevated intraocular pressure. Leads to nerve damage and enlarged optic nerve.
Other risk factors include age, ethnicity, myopia and family history. Patients usually do not experience any symptoms as it slowly causes damage to their peripheral vision.
cataracts- what are they, symptoms
Gradual clouding of the eye’s natural lens. progressive decline in vision as it obstructs light from entering the eye. Color desaturation, night time glare and halos. Develop with age, diabetes, steroids, trauma, radiation
cataract treatment
remove lens and replace with artificial lens
