CNS I PD - Eye Exam Flashcards
Measure Visual Function (ACUITY)
Place patient at a pre-determined location (20 ft) from chart and have them read the LAST LINE THEY CAN CLEARLY MAKE OUT
Distance is measured as a ratio comparing patient performance with an agreed standard
The 1st number is the DISTANCE BETWEEN THE PATIENT AND THEY EYE CHART (20)
The 2nd number is the DISTANCE AT WHICH THE LETTER CAN BE READ BY A PATIENT WITH NORMAL VISUAL ACUITY
20/40 vision –> this means that a patient can JUST BARELY read at 20 feet something that a normal visioned person can read at 40 feet, therefore this person is mild-severe NEAR-SIGHTEDNESS
20/200 = Legally blind (person struggles to read at 20 feet what somebody normally could read at 200 feet - stop signs, etc)
SO 20/10 means patient can read something at 20 feet that normal people can read at 10 feet –> super vision!
External, Direct Examination
Use FOCUSED light
Look initially for AFFERENT PUPILLARY DEFECTS – abnormality where pupil does not sufficiently constrict when encountering light –> can be due to an OPTIC NERVE ABNORMALITY caused by trauma, glaucoma or a tumor!
Check BEFORE administering eye drops because they have a 4-6 hour duration and essentially work by PARALYZING the ciliary muscle (impossible to test constriction)
Be sure to not ALIGNMENT AND MOTILITY, EYELID AND PUPILLARY FUNCTIONS, as well as DEGREE, TYPE, and LOCATION of conjunctival injection(?)
Corneal Exam
Most external aspect of the INTERNAL eye exam
Cornea has 5 layers –> epithelial layer, Bowman’s layer, Stroma, descemet’s membrane, and endothelial layer (most posterior)
FLUORESCEIN STAINING USED TO EXAMINE CORNEAL PROBLEMS –> use STRIPS instead of DROPS because DROPS COULD BE CONTAMINATED WITH PSEUDOMONAS!!!!!
LENS exam
Most common pathology is a CATARACT (clouding of the lens)
Can be congenital or genetic, disease related, age related (common) or trauma associated
Corrected via surgery, and are only done when the cataract INTERFERES WITH NORMAL ACTIVITY
Replace the lens with permanent intraocular lens
Retina and Posterior Segment
Tool of choice is the OPTHALMOSCOPE
Dilate patients eyes to get a better view
Posterior segment has the optic nerve, vitreous humor, retina and vasculature, macula, choroid, lens, ciliary body and zoule, pars plana and plicata (CAREEEE)
Optic nerve should be SHARP with ROUND EDGES containing NO SWELLING and PINK
Papilledema has “fuzzy edge”, swollen nerve
Glaucoma
If C:D (cup to disk) ratio is GREATER THAN 0.5 –> GLAUCOMA!
Development of disk pallor, disk hemorrhage, vessel displacement
