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OcularA&P #1 Midterm
Terms & Definitions Ocular A&P: Adexna, Intro to Orbit, & some muscle questions
| Term | Definition |
|---|---|
| Emmetropia | Normal vision. Rays of light focus on the retina. Absolutely no refractive error |
| Hypertropia | Strabismus in which there is permanent upward deviation of the visual axis of an eye. |
| Myopia | Near-sighted. Rays of light focus anterior to the retina. |
| Astigmatism | Rays of light focus at different areas. |
| Posterior Pole | Area of retina involving optic disc and macula. |
| Cranial Nerves of the Eye and Adnexa | CN II, CN III, CN IV, CN V (V1,V2,V3), CN VI, CN VII, |
| CN II | Optic Nerve (vision)- Sensory |
| CN III | Oculomotor- motor to eye and four external ocular muscles |
| CN IV | Trochlear- motor to superior oblique muscle |
| CN V | Trigeminal -Sensory to the face, globe V1- Ophthalmic -upper face, lids, eye, tip of nose V2- Maxillary -Mid face V3- Mandibular -lower face (don't deal with much in Ophthalmology) |
| Fusion | Ability to use both eyes together and have depth perception. |
| Bones of the Ocular Orbit | Frontal, Lacrimal, Sphenoid, Zygomatic, Ethmoid, Maxillary, Palatine |
| Osteopathy | Any disorder of the bones |
| Words ending in -itis | Means an inflammation |
| Pan | Involves all of an organ |
| Exophthalmos | Forward (anterior) displacement of the globe. |
| Proptosis | Forward (anterior) displacement of the globe. Buldging |
| Endophthalmitis | Inflammation(usually infection) of inside of eye |
| Enophthalmos | Recession (posterior) of globe |
| Cellulitis | Inflammation of subcutaneous tissues |
| The normal average axial length of the globe | 24.5mm |
| The four paranasal sinuses | Frontal, Ethmoid, Sphenoid, Maxillary |
| Hyperemia | Redness (erythema) |
| Chemosis | Swelling (edema) |
| Ecchymosis | Blood in the tissues |
| Ptosis | Drooping lid |
| Normal tear pH | 7.4 |
| These muscles are involuntary (4) | Dilator of iris, Mueller's superior tarsal (lid), Iris sphincter, Ciliary muscles |
| The rectus muscles originate from _______ and insert in ________. | Annulus of Zinn - Spiral of Tillaux |
| Ductions involve one eye and Version involves two eyes. True or False | True |
| Name the two vergence movements | Convergence and Divergence |
| Concomitant | Same measurements in all directions |
| Incomitant | Different measurements in different directions |
| Dextroversion | Right gaze |
| Levoversion | Left gaze |
| Exo- | Eye turning out |
| Infraversion | Down gaze |
| Superior oblique originates from _______ and is innervated by ______ | sphenoid bone, the IV CN |
| Amblyopia | Suppressed vision, also known as "lazy eye" |
| Inferior oblique originates from _____and is innervated by ________ | medial wall,the III CN |
| The four rectus muscles arise from __________ | The Annulus of Zinn |
| Eso- | Eye turning in |
| Tropia | Constant strabismus |
| Synergist (Yoke) | Muscle moving eye in same direction as agonist |
| Antagonist | Muscles moving eye in opposite directions |
| Lateral Rectus arises from _________ and is innervated by the __________ | Annulus of Zinn,the VI CN |
| Vergences are ________ movements and involve _______ | Disconjugated and involve both eyes. *Side note (Disconjugated movement of eyes means rotation of the two eyes in opposite directions, as in convergence or divergence.) |
| Krimsky test | Measures corneal light reflex deviation with prism |
| Hirschberg test | Corneal light reflex test |
| Prisms | Used to measure amount of strabismus |
| 4 prism test | Test for small angle esotropia |
| Cover-Uncover test | Test to determine if it is a tropia or it is a phoria |
| Cross Cover Test | Test to see if any stabismus is present |
| Forced Ductions | Test performed by MD with forceps |
| Bielchowski Test | Head tilt test for superior oblique (IVth CN) palsy |
| OKN (Optokinetic nystagmus) | Normal, induced by moving objects |
| Nystagmus | Rapid, rhythmic, involuntary eye movements, smooth in one direction |
| End-Point Nystagmus | Normal, occurs on lateral versions. A jerky, physiologic nystagmus occurring in a normal individual when attempts are made to fixate a point at the limits of the field of fixation. |
| Phoria | Stabismus only when fusion is disrupted |
| Agonist | Primary muscle moving the eye |
| Hyperopia | Far-sighteness. Rays of light focus behind the retina. |