University:
York University
Course:
NURSING 2534 | Pathophysiology
Academic year:

2023
Views:

136

Pages:

5
Author:

Niklas

Posterior Chamber * Vitreous humor (VH) - maintaining eyeball shape Retina - sensory portion - outermost layer * Photoreceptors: * Rods: black & white * Cones: colors - ROYGBIV * Macula (Fovea Centralis) - central vision * Macular Degeneration - unable to see middle * Blind spot - x photoreceptors * Astigmatism - light focus → IOP → ICP * PR (BSCNII) → DL (cerebrum) * Optic Nerve (CN II) - 2nd cranial nerve Choroid - vascular - blood supply Sclera - hard layer - protection Conjunctiva - transparent membrane * top of sclera * bluish * blood vessels External Structures * Eyebrows - blocks light * Eyelashes - prevents sweat entry to eyes * Conjunctival sac * upper * lower * Eye drops (in middle) + press lacrimal ducts to prevent systemic absorption Eyelids (inner + outer canthus) * Lacrimal Ducts + production of tears * Tears cleanse eyes * Lysosomes (antimicrobial) Diagnosis 1. Visualization * Ophthalmoscopy - lens to retina * Slit Lamp * Consideration: lens + retina * Pupil Dilator: Mydriatics (if constrict: Miotics - Pilocarpine) * Epinephrine * Atropine sulfate * Look Straight * Wear sunglasses → protect eyes b/c pupil still dilated ↳ photosensitivity 2. Snellen's Chart → Assess Visual Acuity * Read Letters + Numbers * Distance = 20 ft (@ meters) * N 20/20 * Legal Blind = 20/200 * near-sighted (Myopia) 20/200 - 20/N * Far-sighted (Hyperopia/Presbyopia) 20/N - 20/20 3. Ishihara Polychromatic Plates → Assess Color Blindness * Numbers + Letters * Identify = N * × Identify = Color Blindness * Men - Hemophilia (Red + Green) Blindness * Women - X-linked carriers 4. Tonometry = Assess IOP → Glaucoma ↳ Painless + Non-Invasive 5. Gonioscopy = Assess ICA >45-OAG <45-CAG 6. PERRLA: Pupils Equally Round & Reactive to Light & Accomodation ↳ Penlight (Torch) ↳ Outer to Inner should be round ↳ (+) pupil constrict ↳ Dilated + Fixed pupil (+) Brain Damage E.A.R.S 1. Outer → Hearing → Air Conduction ↳ Auricle "C-shaped" sound/cartilage ↳ Pinna pull to align ear canal * 3+ pull back + down * <3 pull back + up ↳ Ear canal → passage for air conduction ↳ Ear wax → Protection + filter ↳ Ear wax Impacted Cerumen → Conductive HL → Hearing Loss = Conductive Hearing Loss Partial HR 2. Middle Hearing → Bone conduction ↳ Tympanic Membrane (Ear Drum) converts air conduction → vibration ↳ 3 small bones of ME * Malleus * Incus * Stapes vibrates