OPTH Lec01 Flashcards
Why is the basic eye exam a crucial skill for the PCP?
1) Evaluate ocular complaints and provide definitive diagnosis and treatment, or appropriate referral 2) Detect blinding eye disease, systemic disease, or CNS disorders 3) Establish a baseline- change from baseline indicates progression or improvement
External Anatomy
ocular adnexa, eyelids, tarsal conjunctiva, bulbar conjunctiva
Globe Anterior Chamber
cornea, limbus, sclera, anterior chamber, iris, lens, ciliary body
Globe Posterior Chamber
vitreous cavity, retina, macula, choroid, optic nerve
Scleral
thick outer coating of globe, usually white and opaque
Conjuctiva
thin, vascular tissue covering sclera (bulbar conj) and inner aspect of the eyelids (palpebral conjuctiva)
Uvea/Uveal tract
made up of iris, ciliary body and choroid
Cornea
provides 2/3 of the refractive power, what you need to see clearly
Lens
provides 1/3 of the refractive power
Emmetropia
eye is the correct length and the image is focused on the retina
Hyperopia
eye is too short and the image is focused behind the retina (see things that are close blurry and things that are far clearly)
Myopia
eye is too long and the image is focused in front of the retina (see things that are nearby clearly but cannot see far)
Astigmatism
refracting power of the cornea is different in one meridian than the other (distorts and blurs)
Presbyopia
When the lens loses its ability to accommodate (become more convex) for near vision. Usually in the mid-40s and the distance visual acuity is not changed but the near visual acuity is. Correct with spectacles, contact lenses. Refractive surgery correct refractive error but doesn’t correct presbyopia.
VA
visual acuity; the smallest object a person can identify at a given distance from the eye
OD
oculus dexter - right eye
OS
oculus sinister - left eye
OU
oculuc utergue - both eyes
cc
with correction
sc
without correction
Why must visual acuity testing be done in children before 7?
because visual cortex locks at 7; shuts down and there can be no more development of visual acuity (see with brain not eyes so it’s important for those pathways to develop)
Name the specific tests and what they are assessing:
1) Confrontational eye testing
2) Color vision testing tests for occupational, retina or optic nerve disease (7-10% of men, red/green, X-linked)
3) Fluorescein staining: to detect a corneal epithelial defect; use a Wood lamp or cobalt blue filter
4) Upper lip eversion - look for superior foreign body
5) Congenital color deficiency - red/green (7-10% of males, x-linked, recessive)
6) Ishihara plates
Who will see this?
Anyone will see a 12 on it
Who will see this?
A right sided dichromate will see a 21