Week 10 - Eyes

Inspection of anterior chamber, iris, pupils

Anterior Chamber: clarity, bulging iris, and blood Iris: color, size, shape, and symmetry Pupils: size, shape, reaction to light- direct and consensual, test accommodation

Family History

Congenital eye disease Cataracts Glaucoma Macular degeneration Diabetes

Pale Palpebral Conjunctiva

Anemia

Pupillary Response

Darken the room Ask the person to gaze into the distance Advance the light from the side Note the response of the pupil Gauge the pupil size in millemeters Normal resting size: 3, 4, or 5 mm (not everyone is textbook) R 3mm (resting) 1mm (response to light)

Eyebrows

If eyebrow doesn't move there could be paralysis with facial nerve XII Hypothyroidism; deficient eyebrow production (as well with swimmers due to chlorine and as people age eyebrows thin)

Do you have double vision (diplopia)? Are the images side by side (horizontal diplopia) or on top of each other(vertical diplopia)? Does this persist with one eye closed? Which eye is affected?

Lesion in brainstem, paralysis of extraocular muscle, cornea or lens defect

Hordeolum

Stye: A painful, tender red infection in a gland at the margin of the eyelid

Recording the Examination

Vision Acuity measurements Tenderness? Color? Deformities? Opacities? Peripheral Fields Drainage EOMs Structures

Extraocular Muscles

star pattern

Blepharitis

(eyelid infection caused by a species of staph) Red inflamed lid margins in blepharitis, often with crusting

The Light Reaction

A lightbeam shining onto one retina causes pupillary constriction both in that eye, termed the direct reaction to light and in the opposite eye, the consensual reaction. The initial sensory pathways are similar to those described for vision: retina, opticnerve, and optic tract. The pathways diverge in the midbrain, however,and impulses are transmitted throughthe oculomotor nerve, CN III, to theconstrictor muscles of the iris of eacheye.

Chalazion

A subacute nontender usually painless nodule involving ameibomian gland. May become acutely inflamed but, unlike a sty, usually points inside the lid rather than on the lid margin.

Scotoma

Abnormal blind spot in the visual field surrounded by an area of normal or decreased vision

Do you experience: Redness? Excessive tearing?Discharge? Crusting?

Allergies, infection

Coroner Syndrome

Aortic Dissection

The muscle that raises the upper eyelid is innervated by: A. CN II B. CN III C. CN IV D. CN VI

CN III or oculomotor nerve innervates the levator palpebrae muscle, which raises the upper eyelid. CN II is the optic nerve, CN IV is the trochlear nerve, and CN VI is the abducens nerve.

Peripheral Vision Acuity

Confrontation Test Compares with your own peripheral vision Position yourself 2 feet away "Flicking your finger toward periphery Patient says "now" when sees your finger

Inspection of External Structures

Conjunctiva: color, moisture, lesions, and foreign bodies Sclera: color, moisture, lesions, or tears

Macular Degeneration

Damage to the cells in the retina responsible for central vision (Macula) cause vision to be blurry and finally fade to a dark spot in the center of the image. This is a leading cause of blindness in older adults Important cause of poor central vision inthe elderly. Types include dryatrophic (more common but less severe) and wet exudative, or neovascular. Undigested cellular debris, called drusen, may be hardand sharply defined, as seenbelow, or soft and confluent withaltered pigmentation. Can go blind Cant drive "what degree is the macular degeneration"

Difficulties with close work or seeing at a distance

Difficulty with close work suggests: hyperopia (farsightedness) presbyopia (aging vision) with distances myopia(nearsightedness)

The Health History

Do you have any history of HTN, DM, hyperthyroidism? Do you currently use any glasses/contact lens? Have you been diagnosed with cataracts, glaucoma, or any other vision problems? Have you had any eyes surgeries or injuries to your eyes? Are you taking any medications? Are you frequently out in the sun?

Lifestyle Habits

Do you smoke? Do you wear sunglasses? Do you use protective eyewear? Are you using any medications/drugs that dry out the eye?

Primary open-angle glaucoma

Effects both eyes, asymptomatic- caused by decrease in aqueous humor. S/S: tired eyes, diminished peripheral vision, halos around lights, hardening of eyeball, increased intraocular pressure

What is the relationship of the eyes to other systems?

Endocrine System Exophthalmos: abnormal protrusion of the eyeball (can be caused by hyperthyroidism) Diabetes: cataracts Cardiovascular Digestive: Jaundice Urinary: ocular edema- Urinary retention or individuals on dialysis, not uncommon for edema Allergic and Neurological: Injected Eyes=Blood Shot Eyes (Itchy, stinging, should be no pain) Neurological: ptosis (abnormal closure of one eyelid) coroner syndrome, Nystagmus, lesions on the optic nerve Hematological: anemia (pale palpebral conjunctiva) Integumentary: lack of eyelashes, Hordeolum, Blepharitis, Chalazion,

Visual Field

Entire area seen by eye when it looks at central point Center of circle represents focus of gaze Circumference is 90degrees from the line of gaze Fields divided into quarters, gaze is farthest on temporal sides A lack of retinal receptors at the optic disk produces an oval blind spot in the normal field of each eye 15degrees temporal to the line of gaze

Blurred vision

Entire field or part Both eyes or one If sudden unilateral visual loss is painless,consider vitreous hemorrhage from diabetes or trauma, maculardegeneration, retinal detachment, retinal vein occlusion,or central retinal artery occlusion. If painful,causes are usually in the cornea and anterior chamber as in corneal ulcer, uveitis, traumatic hyphema, and acute glaucoma. Optic neuritis from multiple sclerosis may also be painful. Immediate referral may be warranted. If bilateral and painless,medications that change refraction such as cholinergics, anticholinergics, and steroids may contribute. If bilateral and painful, consider chemical or radiation exposures. If the onset of bilateral visual loss is gradual, this usually arises from cataracts or macular degeneration

Palpation of External Structures

Eye ball: consistency and tenderness Lacrimal glands and ducts: tenderness and excessive tearing

Eye protection

Eye injury can occur anywhere with many different activities. Must assess environment and activities and use appropriate protective device if warranted. Emergency eye care education is important to ensure correct steps are taken to preserve vision. Avoid direct sunlight, and be sure to correctly use sunglasses. Be sure there are appropriate eye wash stations in work areas

External Structures of the Eye

Eyebrow Eyelid (lower & upper) Eyelashes Lacrimal Gland Conjunctiva

Autonomic Nerve Supply to the Eyes

Fibers traveling in the oculomotor nerve (CN III) and producing pupillary constriction are part of the parasympathetic nervous system. The iris is also supplied by sympathetic fibers. When these are stimulated, the pupil dilates, and the upper eyelid rises a little, as if from fear. The sympatheticpathway starts in the hypothalamus and passes down through the brain-stem and cervical cord into the neck. From there, it follows the carotid artery or its branches into the orbit. A lesion anywhere along this pathway may impair sympathetic effects that dilate the pupil.

Do lights flashacross the field of vision?

Flashing lights or new vitreousfloaters suggest detachment of vitreous from retina. Prompt eye consultation is indicated.

Do floaters accompany this symptom? Does it feel like a curtain is falling? Are there specks in the vision or areas where you are unable to see (scotoma)? If so, do they move in the visual field with shifts of gaze or arethey fixed?

Flashing lights? Detachment of vitreous from retina Floaters? Vitreous floaters Specks? Fixed defects, lesions in retina or visual pathway

Test Accomodation

Focus on a distant object Have individual shift gaze to a near object Can use your finger about 3 inches from the nose Normal Response: Pupils constrict and converge

Positions for peripheral vision testing

If you find a defect, try to establish its boundaries.Test one eye at a time. If you suspect a temporal defect in the left visual field, for example, ask the patient to cover the right eye and, with the leftone, to look into your eye directly opposite. Then slowly move your wig-gling fingers from the defective area toward the better vision, noting wherethe patient first responds. Repeat this at several levels to define the border.

Glaucoma

Increased intra ocular pressure Affects men more than women Affects African Americans more often than Caucasians Ciliary injection: dilation of deeper vessels that are visible as radiating vessels or a reddish violet flusharound the limbus. Ciliary injection is an important sign but may not be apparent. The eye may be diffusely red instead. Other clues include: pain, decreased vision, unequal pupils, and a less than perfectly clear cornea. Pain: severe, aching, deep Vision: decreased Ocular discharge: absent Pupil: dilated, fixed Cornea: steamy, cloudy Significance: acute increase in intra ocular pressure (emergency)

Muscles and Cranial Nerves

Muscles of iris: control pupillary size (constrict/dilate) Muscles of the ciliary body: control thickness of lens (focus on near or distant objects) If one of these muscles is paralyzed the eye will deviate from its normal position in that direction of gaze and the eyes will no longer appear conjugate or parallel CN II is the optic nerve CN III is the oculomotor nerve CN IV is the trochlear nerve CN VI is the abducens nerve.

Vision screening

Newborn to 5 for strabismus(point in different directions) Ages 3 to 5 for amblyopia (lazy eye) School-age children, adolescents, young adults for refractive errors All adults to evaluate eye health Over age 65: more prevalent for refractive errors, cataracts, macular degeneration, glaucoma Certain disease processes should have more frequent examinations: diabetes

Retinal Vessels and Retina

Note arteries, vessels, size, color, texture

Cataracts

Nuclear cataract. A nuclear cataract looks gray when seen by a flashlight. If thepupil is widely dilated, the gray opacity is surrounded by a black rim. Peripheral cataract. Produces spoke-like shadows that point inward—gray againstblack, as seen with a flashlight, or black against red with an ophthalmoscope. A dilated pupil, facilitates this observation.

Conjunctiva

Opening between eyes = palpebral fissure Bulbar conjunctiva = sclera (covers most of the anterior eyeball and adheres loosely to underlying tissue) Palpebral conjunctiva = lines the eyelids The two parts of the conjunctiva merge in a folded recess that permits movement of the eyeball

Subconjunctival hemorrhage

Pattern of redness: Leakage of blood outside of the vessels, producing a homogeneous, sharply demarcated, red area that fadesover days to yellow and then disappears Pain: absent Vision: not affected Ocular discharge: absent Pupil: not affected Cornea: clear Significance: Often none. May result from trauma, bleeding disorders,or a sudden increase in venous pressure, as from cough

Conjunctivitis

Pattern of redness: conjunctival injection (diffuse dilation of conjunctival vessels with redness that tends to be maximal peripherally Pain: mild discomfort rather than pain Vision: not affected except for temporary mild blurring due to discharge Ocular discharge: watery, mucoid, or mucopurulent Pupil: not affected Cornea: clear Significance: bacterial, viral, and other infections, allergy, irritation

Equipment

Penlight Snellen Chart Newspaper Ophthalmoscope Cotton Ball Cotton Swab

Photophobia

Photophobia or light sensitivity is usually from excess light entering the eye, which may overexcite thephotoreceptors in the retina.

Viewing the eye with the Ophthalmoscope

Posterior part of eye= fundus (structures include: retina, choroid, fovea, macula, optic disk, and retinal vessels) Optic nerve can be visualized via the Ophthalmoscope at the optic disk (optic disk should be the medial landmark) Lateral and inferior to the disk: small depression in the retinal surface which marks the point of central vision Around the small depression is a darkened circular area called fovea The circular; Macula (microscopic yellow spot) surrounds the fovea but has no discernible margins It is unusual to see the Vitreous body (a transparent mass of gelatinous material) it fills the eyeball behind the lens and helps to maintain shape of the eye

Eye History

Premature birth Trauma Surgery Infections Disease Structural deformities Last eye examination Color blindness test (red/green) Glasses or contacts? Hard or soft lenses? When did you first start wearing them? Corrective or cosmetic? How do you care for them? Do you share contacts? How long are the contacts in your eyes

Care of contact lenses

Proper care to avoid infection, injury, or scarring to cornea. Follow manufacturers recommendations for use, care, and storage. Use good handwashing techniques . Inspect cornea during exams to ensure there are no scratches or damage.

Vision acuity: Near vision

Rosenbaum chart Hold card 14 inches from patient Helps identify need for bifocals or reading glasses (45year olds or older) Patient may choose their own distance

The Eye

Sensory organ Spherical structure that focuses light on retina Muscles of iris control pupillary responses Enables vision Cranial nerve component CN III: oculomotor nerve CN IV and VI: extraocular movements

If the visual field defect is partial, is it central, peripheral, or only on oneside?

Slow central loss in nuclearcataract (p. 239), macular degeneration; peripheral loss in advanced open angle glaucoma(p. 238); one-sided loss in hemianopsia and quadrantic defects(p. 222).

Visual acuity (Distal)

Snellen eye chart or "E" chart Cover one eye with index card, read smallest line Repeat with other eye Note if testing is completed with corrective lenses Findings recorded as fraction (numerator is distance patient is from chart, denominator is distance normal eye can read chart) So 20/200 means: at 20 feet patient can read print what a person with normal vision could read at 200 feet The larger the second number the worse the vision (20/200 legally blind)

Tear Production and the Lacrimal Gland

Tears prevent the conjunctiva and cornea from drying, inhibits microbial growth, and gives a smooth optical surface to the cornea Fluid comes from the meiobomian glands, conjunctival glands, and lacrimal gland. Lacrimal gland lies mostly within the bony orbit; above and lateral to the eyeball Tear fluid extends across the eye and drains medially through two holes called the lacrimal puncta, tears then pass into the lacrimal sac and into the nose through the nasolacrimal duct

Macula

The circular; Macula (microscopic yellow spot) surrounds the fovea but has no discernible margins

Extraocular Movements

The coordinated action of six muscles: the four rectus (superior, lateral, medial, and inferior) and two oblique (inferior andsuperior), control the eye. To test the function of each muscle and the nerve that supplies it, ask the patient to move the eye in the direction controlled by that muscle. There are six cardinal directions,indicated by the lines on the figure below. When a person looks down and to the right, for example,the right inferior rectus (CN III) is principally responsible for moving theright eye, whereas the left superior oblique (CN IV) is principally responsi-ble for moving the left. If one of these muscles is paralyzed, the eye willdeviate from its normal position in that direction of gaze and the eyes willno longer appear conjugate, or parallel

Chronic open-angle glaucoma

The type of glaucoma that results from an overproduction of aquenous humor

Circulation of Aqueous Humor

Vitreous Humor: clear gel that fills the space between the lens and retina Aqueous Humor: clear liquid that fills the anterior and posterior chambers of the eye (it circulates between the cornea and the lens) The Aqueous Humor is produced by the ciliary body, circulates through posterior chamber through the pupil into the anterior chamber and drains through the canal of Schlemm. (system helps to control ocular pressure)

"Floaters" in the Eyes

Vitreous floaters may be seen as dark specks or strands between the fundus and the lens.

The Near Reaction

When a person shifts gaze from a far object to a near one, the pupils constrict. This response, like the light reaction, is mediated by the oculomotor nerve(CN III). At the same time as the pupillary constriction, but not a part of it, are: (1) convergence of the eyes, an extraocular movement; (2) accommodation an increased convexity of the lenses caused by contraction of the ciliary muscles This change in shape of the lenses brings near objects into focus but is not visible to the examiner.

Field defects that are all or partly temporal include

When the patient's left eye repeat-edly does not see your fingers untilthey have crossed the line of gaze, aleft temporal hemianopsiais present.Hemianopsia is when the patient isunable to see in half of the visualfield and is generally on one side. This can occur after a cerebrovascular accident or stroke. The patient isunable to distinguish objects to theside of the visual midline. The loss is contralateral, which is on the opposite side of the brain lesion.

Lesions on the optic nerve

affects optic nerve pathways

Inspection of Cornea

clarity and abrasions, corneal reflex

Inspection of Lacrimal Ducts

color, edema, excessive tearing or drainage

Inspection of Lids and Lashes

color, lesions, edema, symmetry, position and distribution of lashes

Optic Disc and Physiologic Cup

color, size, shape, borders, cup-disc ratio

Nystagmus

constant involuntary, cyclical movement of the eyeball as a result from demyelinization of nerve fibers

Visual Pathways

light reflected from image must pass through the pupil and be focused on sensory neurons in the retina image projected there is upside down and reversed right to left an image from the upper nasal visual field thus strikes the lower temporal quadrant of the retina nerve impulses stimulated by light are conducted through the retina, optic nerve, and optic tract on each side, then on through a curving tract called the optic radiation (this ends in the visual cortex part of the occipital lobe)

Opthalmoscopy

use of an opthalmoscope to view the interior of the eye Red reflex: presence, opacities

Visual Field w/ Both Eyes

when using both eyes, the two visual fields overlap in an area of binocular vision laterally vision is monocular