Eyes Chapter 15 PDF

Chapter 15 EYES  2 Structur e of the eye Structure of the eyes cont’ Copyright © 2020 by Elsevier Inc. All rights reserved. Direction of Movement Copyright © 2020 by Elsevier Inc. All rights reserved. ...

Chapter 15 EYES  2 Structur e of the eye Structure of the eyes cont’ Copyright © 2020 by Elsevier Inc. All rights reserved. Direction of Movement Copyright © 2020 by Elsevier Inc. All rights reserved.  5 Visual Reflexes  Pupillary light reflex: normal constriction of both pupils when bright light shines on retina  When one eye exposed to bright light, two things happen:  direct light reflex  constriction of that pupil  consensual light reflex  simultaneous constriction of other pupil  The optic nerve carries the sensory afferent message in and then synapses with both sides of brain  6 Visual Reflexes (Cont.)  Fixation: maintaining vision toward an object attracting person’s attention  The rapid ocular movements required to keep the image on the fovea are impaired by drugs, alcohol, fatigue, and inattention  Accommodation: when the eye adapts in order to keep focus on a moving object  Pupils constrict and eyes converge together towards the center (think cross- eyed…the eyes converge) Developmental Competence: 7 Aging Adults  Pupil size decreases  Lens loses elasticity  Becomes hard and glasslike, causing presbyopia (difficulty seeing near)  By age 70, normally transparent fibers of lens begin to thicken and yellow, the beginning of cataracts  Visual acuity may diminish gradually after age 50, and more so after age 70  8 Developmental Competence: Aging Adults (Cont.)  Most common causes of decreased visual functioning in older adults include: 1. Cataract formation, or lens opacity, resulting from a clumping of proteins in lens 2. Glaucoma, or increased intraocular pressure; chronic open- angle glaucoma is most common type 3. Macular degeneration, or breakdown of cells in macula of retina 4. Loss of central vision is most common cause of blindness; person is unable to read fine print, sew, or do fine work; loss of central vision may cause great distress 5. Diabetic retinopathy, a leading cause of blindness in adults ages 25 – 74 years as a result of chronic uncontrolled diabetes  9 Cataracts  10 Glaucoma  11 Macular Degeneration  12 Diabetic retinopathy   Cataracts are a leading cause of blindness worldwide.  Glaucoma incidence increases with age, black or Hispanic heritage, diabetes, and family history  African Americans 3 to 6 times more likely to develop than Caucasian Americans.  Primary angle glaucoma is leading cause of blindness in African Americans and Hispanics.  Culture and Age-related macular degeneration  Increase seen in US adults by the age Genetics  of 80 More prevalent in Caucasians  Risk factors  Positive family history, cigarette smoking, hyperopia, light iris color, HTN, hypercholesterolemia, and female gender  Visual impairment (VI)  Not being able to see letters on the eye chart at line 20/50 or below  Highest numbers seen in Caucasian women and older adults  Visual screening crucial—safety. concerns  14 What do we ask our patient?  15 Subjective Data  Vision difficulty: decreased acuity, blurring, blind spots  Pain  Strabismus, diplopia  Redness, swelling  Watering, discharge  History of ocular problems  Glaucoma  Use of glasses or contact lenses  Self-care behaviors  16 Vision Difficulty Questions  Any difficulty seeing or any blurring? Blind spots? Come on suddenly or slowly? One eye or both?  Constant, or does it come and go?  Do objects appear out of focus or clouding of objects?  Do spots move in front of your eyes? One or many? In one or both eyes?  Any halos, rainbows, rings around objects?  Any blind spot? Does it move as you shift your gaze? Any loss of peripheral vision?  Any night blindness?  17 Pain Questions  Any eye pain? Please describe  Come on suddenly?  Quality: burning or itching? Or sharp, stabbing pain; pain with bright light?  A foreign body sensation? Or deep aching? Or headache in brow area?  18 Other Assessment Questions  Strabismus, diplopia: Any history of crossed eyes? Now or in the past? Does this occur with eye fatigue? Ever see double? Constant, or does it come and go? In one eye or both?  Redness, swelling: Any redness or swelling in eyes? Any infections? Now or in past? When do these occur? In a particular time of year?  Watering, discharge: Any watering or excessive tearing? Any discharge? Is it hard to open your eyes in the morning? What color is the discharge?  Past history of ocular problems: Any history of injury or surgery to eye? Any history of allergies?  Glaucoma: Have you ever been tested for glaucoma? Do you have any family history of glaucoma?  Use of glasses or contact lenses: Do you wear glasses or contact lenses? How do they work for you? Last time your prescription was checked? Was it changed? If you wear contact lenses, are there any problems such as pain, photophobia, watering, or swelling?  19 Additional History for Aging Adults  Have you noticed any visual difficulty with climbing stairs or driving? Any problem with night vision?  When was last time tested for glaucoma?  Any aching pain around eyes? Any loss of peripheral vision?  If you have glaucoma, how do you manage your eye drops?  Is there history of cataracts? Any loss or progressive blurring of vision?  Do your eyes ever feel dry or burning? What do you do for this?  Any decrease in usual activities, such as reading or sewing?  20 What’s the difference?  Near sighted (myopia)  can see near but not far  Far sighted (hyperopia)  can see far but not near  Presbyopia  AGE-RELATED far sightedness starting after age 40  21 How do we assess our patient?  22 Testing Central Visual Acuity  Snellen alphabet chart is most commonly used and accurate measure of visual acuity  Place chart eye level with person standing 20 feet away and cover one eye  If person wears glasses or contact lenses, leave them on; remove only reading glasses  Ask person to read through chart to smallest line of letters possible  Record the number of the last line the person can read  23 Testing Near Sightedness  Test near vision with handheld vision screener with various sizes of print (Jaeger card)  Hold card in good light about 14 in. from the eye; this distance equals print size on 20-foot chart  Test each eye separately, with glasses on  Normal result is “14/14” in each eye, read without hesitancy and without moving card closer or farther away  When no vision screening card is available, ask person to read from a magazine or newspaper  24 Confrontation Test  Gross measurement of peripheral vision; compares person’s peripheral vision with yours  Position yourself at eye level with person about 2 feet away  Direct person to cover one eye and look at you with the other  Cover your own eye opposite to person’s covered one; you are testing uncovered eye  If they cover their right, you cover your left, etc.  Hold your finger midline between you and person and slowly advance it in from periphery in several directions  Person should see the target at the same time as you  https://youtu.be/rk5TptEGowo  25 Testing Extraocular Muscle Function: Corneal Light Reflex  Also called the Hirschberg test  Assess parallel alignment of eyes by shining a light toward person’s eyes  Direct person to stare straight ahead as you hold the light about 12 in. away  Note reflection of light on corneas; should be in exactly same spot on each eye  Asymmetry indicates deviation due to muscle weakness or paralysis  https://youtu.be/N0x-Jx4zvO4  26 Diagnostic Positions Test  Testing the six cardinal positions of gaze will elicit any muscle weakness during movement  Ask person to hold head steady and follow movement of your finger with eyes only  Hold target back about 12 in. so person can focus comfortably, and move it to each of six positions; hold momentarily, then back to center  A normal response is parallel tracking of the object with both eyes  Note any nystagmus, a fine oscillating movement best seen around iris  Mild nystagmus at extreme lateral gaze is normal; nystagmus at any other position is not.ys  thttps://youtu.be/5vPCL7MaSDk avid  https://youtu.be/w2CttMSxutY  General Inspection and 27 Eyebrows  General: begin with external points, work inward  Already you will have noted person’s ability to move around room, with vision functioning well enough to avoid obstacles and to respond to your directions  Also note facial expression; relaxed expression accompanies adequate vision  Eyebrows  Look for symmetry between the two eyes  Normally eyebrows are present bilaterally, move symmetrically as expression changes, and have no scaling or lesions  28 Eyelids, Lashes, and Eyeballs  Eyelids and lashes  Upper lids normally overlap superior part of iris  Palpebral fissures (the opening in between the eyelids) horizontal in non- Asians; Asians have an upward slant  Note that eyelashes are evenly distributed along lid margins and curve outward  Eyeballs  Eyeballs aligned normally in their sockets with no protrusion or sunken appearance  African Americans normally may have slight protrusion of eyeball beyond supraorbital ridge  29 Conjunctiva and Sclera  Ask person to look up; using thumbs, slide lower lids down, being careful not to push against eyeball  Conjunctiva should be clear and show normal color of structure below (pink over lower lids and white over sclera); Sclera should be china white  For African Americans:  Occasionally have gray-blue or “muddy” color to sclera  May see small brown macules (like freckles) on the sclera, which should not be confused with foreign bodies or petechiae  Possible yellowish fatty deposits beneath lids away from cornea  Do not confuse these yellow spots with overall scleral yellowing that accompanies jaundice  30 Lacrimal Apparatus  Ask person to look down; with thumbs, slide outer part of upper lid up along bony orbit to expose under lid; inspect for any redness or swelling  Presence of excessive tearing may indicate blockage of nasolacrimal duct  Check by pressing index finger against sac, just inside lower orbital rim, not against side of the nose  Pressure will slightly evert lower lid, but there should be no other response to pressure  31 Cornea, Lens, Iris, and Pupil  Shine light from side across cornea, and check for smoothness and clarity  There should be no opacities (cloudiness) in cornea, anterior chamber, or lens  Iris normally appears flat, with round regular shape and even coloration  Note size, shape, and equality of pupils; normally pupils appear round, regular, and of equal size in both eyes  32 Pupils Equal, Round, React to Light, and Accommodation  Are pupils equal in size?  Are pupils round? PERRLA  33 PERRLA Cont’  Are pupils responding to the pupillary light reflex?  Direct light reflex  Constriction of the pupil that light is shined on  Consensual light reflex  Simultaneous constriction of other pupil https://youtu.be/T4iQrVBDvEY  34 PERRLA Cont’  Do eyes accommodate?  Test for accommodation by asking person to focus on a distant object to dilates the pupils  Have person shift gaze to near object (such as your finger) held about 3 in. from nose  Normal response includes pupillary constriction and convergence of eyes (cross- eyed)  If so, then PERRLA is intact  If one assessment finding is abnormal then PERRLA is not intact  35 Question The nurse is assessing the pupils of a patient with a pen light. Which finding would be considered normal? a. Both eyes cross when exposed to the light. b. The patient’s pupils are fixed and dilated in response to light. c. Both pupils dilate in response to light. d. Both pupils constrict in response to light.  Infants and Children: 36 Visual Acuity  Eye examination often skipped at birth because of transient edema of lids from birth trauma or from the instillation of silver nitrate at birth (drops or ointment to prevent conjunctivitis);  Eyes should be examined within a few days and at every well child visit thereafter  In newborn, test visual reflexes and accompanying behaviors  Test light perception using blink reflex; neonate blinks in response to bright light  Pupillary light reflex shows pupils constrict in response to light  These reflexes indicate that the lower portion of the visual apparatus is intact but does not prove that infant can see (full eye examination is done later)  Infants and Children: 37 Visual Acuity (Cont.) As you introduce an object to infant’s line of vision, note these attending behaviors:  Birth to 2 weeks: refusal to reopen eyes after exposure to bright light; increasing alertness to object; infant may fixate on an object  By 2 to 4 weeks: infant can fixate on an object  By 1 month: infant can fixate and follow light or bright toy  By 3 to 4 months: infant can fixate, follow, and reach for toy  By 6 to 10 months: infant can fixate and follow toy in all directions  Infants and Children: 38 Eye Structures Conjunctiva and sclera  Sclera should be white and clear, although it may have a blue tint as a result of thinness at birth; lacrimal glands are not functional at birth  Iris and pupils  Iris normally blue or slate gray in light- skinned newborns and brown in dark- skinned infants; by 6 to 9 months, permanent color differentiated  39 Aging Adult: Developmental Competence  Visual acuity  Perform same examination as described in adult section  Central acuity may decrease, particularly after 70 years of age; peripheral vision may be diminished  Ocular structures  Eyebrows may show loss of outer one third to one half of hair because of decrease in hair follicles; remaining brow hair is coarse  As result of atrophy of elastic tissues, skin around eyes may show wrinkles or crow’s feet; upper lid may be so elongated as to rest on lashes  40 Developmental Competence (Cont.)  Aging adult  Ocular structures  Eyes may appear sunken from atrophy of orbital fat; orbital fat may herniate, causing bulging at lower lids and inner third of upper lids  Lacrimal apparatus may decrease tear production, causing eyes to look dry and lusterless and person to report a burning sensation  Pingueculae commonly show on sclera  These yellowish elevated nodules are due to thickening of bulbar conjunctiva from prolonged exposure to sun, wind, and dust; they appear at 3 and 9 o’clock positions  41 Developmental Competence (Cont.)  Aging adult  Ocular structures  Cornea may look cloudy with age  Arcus senilis commonly seen around cornea  Gray-white arc or circle around limbus due to deposition of lipid material  As more lipid accumulates, cornea may look thickened and raised, but arcus has no effect on vision  Xanthelasma: soft, raised yellow plaques occurring on lids at inner canthus  They commonly occur around fifth decade of life and more frequently in women, occur with both high and normal levels of cholesterol, and have no pathologic significance  Developmental Competence 42 (Cont.)  Aging adult  Ocular structures  Pupils small in old age; pupillary light reflex may be slowed  Lens loses transparency and looks opaque  Ocular fundus  Retinalstructures generally have less shine; blood vessels look paler, narrower, and attenuated; arterioles appear paler and straighter, with a narrower light reflex Summary Checklist: Eye Examination  Test visual acuity  Snellen eye chart  Test visual fields  Confrontation test  Inspect EOM function  Corneal light reflex, cover test, diagnostic positions test  Inspect external eye structures  Inspect anterior eyeball structures  Inspect ocular fundus 43  Optic disc, retinal vessels, general background, and macula  44 Abnormal conditions of retina  Diabetic retinopathy is a common issue from uncontrolled diabetes, where the elevated glucose levels can damage the small vessels and causes issues, including blindness Abnormal Findings: 45 Extraocular Muscle Dysfunction  Strabismus: eye misalignment; cross -eyed  Esotropia: form of strabismus; eyes turn inward  Exotropia: form of strabismus; eyes turn outward  Paralysis: paralysis of the eye muscles; can cause double vision  Abnormal Findings: 46 Abnormalities in the Eyelids  Periorbital edema  Ptosis: drooping upper lid  Abnormal Findings: 47  Blepharitis, inflammation of eyelids Conjunctivitis, infection of the conjunctiva