Optometry Vocabulary

Light is bent (refracted) primarily by the ______________

Cornea

Light is bent (refracted) secondarily by the _______

Lens

Light is focused onto the __________ which contains specialized neural cells called photoreceptors to process light and change it into a chemical signal which is transmitted through the visual pathway.

Retina

Majority of the light is focused onto the ___________ -> clearest portion of vision.

Macula

Chemical signal exits the eye via the ___________________.

Optic Nerve (CN II)

Which lobe is involved in visual processing??

The Occipital Lobe

The ability to clearly see an image at near involves a process known as ____________________ which is controlled by CN III (Oculomotor Nerve).

Accomodation

Testing Visual Acuity: Distance _________ ft vs. Near ________ cm

Distance - 20 ft
Near - 40 cm

Equipment used to cover the eye

Occluder

Snellen Fraction 20/20

Test Distance/Letter Size: document the smallest row of letters on the visual acuity chart where the patient was able to correctly identify half or more of the letters

______________ condition in which the image is not clear

Refractive Error

Hyperopia

Farsightedness (Distance can be seen clearly, but close ones do not come into proper focus). Some people may not notice any problems with their vision, especially when they are young. With significant hyperopia - vision can be blurry for objects at any distance, near or far.

Myopoia

Nearsightedness, Most Common refractive error of the eye, cornea is too curved for the length of the eyeball (see close objects clearly, but can not focus on objects further away). Light comes to focus in front of the retina instead of on the retina.

Astigmatism

Irregularly shaped eyeball leading to improper focus of objects. Does not focus light evenly onto the retina - images appear blurry and stretched out.

Presbyopia

Age-related condition in which the ability to focus up close becomes more difficult. As the eye ages, the lens can no longer change shape enough to allow the eye to focus close objects clearly.

Legal Blindness

Visual acuity worse than 20/200 in the better seeing, corrected eye.

Driving in AZ

Visual acuity must be better than 20/40 in the better seeing, correct eye to obtain a driver's license with no restrictions.

Daytime Restrictions

Visual acuity must be at least 20/60 in better seeing, corrected eye to obtain a drives license with daytime restrictions.

Depth perception utilizes one eye or two?

Two - two images must be focused on the respective maculas and must be processed together in the occipital cortex.

Strabismus

Two eyes do not work together to point at a target simultaneous. Eye condition from a lack of coordination of the eye muscles which prevents the two eyes from focusing at the same point in space.

EXOtropia

Form of Strabismus in which one eye turns outward.

ESOtropia

Form of Strabismus in which one eye turns inward.

Test for Eye Alignment is the _________________

Cover/Uncover test: Have pt look at a target and observe if both eyes appear aligned. Cover one eye, as the eye is covered, the clinician should watch the uncovered eye to see if the eye makes any 'correcting motion' - if so = strabismus.

Cranial Nerves of the Eye

Muscles, Pupils, Corneal Reflex

Visual Pathway Anatomy

Visual Field

List the Six Pairs of Extraocular Muscles

1. Medial Rectus
2. Lateral Rectus
3. Superior Rectus
4. Inferior Rectus
5. Superior Oblique
6. Inferior Oblique

List the 4 Oculomotor Cranial Nerves of the EOMs

Oculomotor (CN III)
-Medial Rectus
-Inferior Rectus
-Superior Rectus
-Inferior Oblique

List the Trochlear Cranial Nerve of the EOMs

Trochlear (CN IV)
-Superior Oblique

List the Abducens Cranial Nerve of the EOMs

Abducens (CN VI)
-Lateral Rectus

Test for extraocular muscle in both eyes!

Diagnostic H pattern for both eyes. Move the target into 9 positions of gaze. Doctor should be 30-40 cm directly in front of the patient. If a patient reports DIPLOPIA (double vision) or PAIN - this should be followed up with a referral.

Pupil

Variable sized black circular opening in the center of the iris that regulates the amount of light that enters the eye.

Miosis

Excessive constriction of the pupil of the eye.

Mydriasis

Dilation of the pupil of the eye.

The Pupil Response

Due to the anatomy of the visual pathway, when a sensory stimulus is presented in one eye - there will be motor output of both eyes.

Direct Response

Monitoring the pupil response (constriction) of the eye that is being directly stimulated (light in the eye) by the sensory input.

Consensual Response

Monitoring the pupil response of the eye that is not being stimulated by the sensory input.

Decussation of the Eye

Crossing in the shape of an X connecting corresponding parts of the brain.

Swinging Flashlight Test

Compares the afferent system of the right eye vs. the left eye. Check pupillary response in a dim room checking each eye for 2-3 seconds 1-2 inches away from the eye. If one pupil dilates and remains dilated, there is a Relative Afferent Defect.

PERRL - APD

Pupils Equal, Round, React to Light, No Afferent Pupillary Defect

Anisocoria

Unequal pupil sizes with varied causes ranging from benign to life threatening (found in less than 4% of the population >1mm). Estimated 20-40% population have a physiologic (benign) difference of <1 mm between the right and left pupil.

Adie's Tonic Pupil

Tonic pupil will not constrict in light due to damage of the ciliary ganglion. Anisocoria appears GREATER IN THE LIGHT.

Horner's Syndrome

TRIAD: Ptosis (drooping of the eyelid), Miosis (excessive constriction of the pupil of the eye), and anhydrosis/Anhidrosis (inability to sweat normally). Caused by interruption of the sympathetic pathway to the eye, problem GREATER IN THE DARK.

Visual Field

Entire area of space that a person can see at one time (patient's peripheral or side vision).

Visual Pathway

The series of cells/synapses that visual information takes from being processed as light in the retina into a chemical signal that synapses throughout the brain resulting in complex processing within the visual cortex located in the occipital lobe.

4 Distinct Quadrants of the Visual Field

Superior Temporal OD (Rt Eye), Inferior Temporal (OD), Superior Temporal OS (Lt Eye), Inferior Temporal OS (Lt Eye). Overlap occurs in the nasal region. Each quadrant of the visual field is processed within a specific area of the brain.

Evaluating the Visual Field

Using the patients four quadrants, hold up a number with your fingers - 1, 2 or 5 - 40 cm from the patient (about 40cm from the examiner as well. The patient should correctly identify the number of fingers presented in each quadrant for each eye, if not note that quadrant. FTF C (Full to Finger Count). If the patient has a visual field defect, the finding should be followed up with an appropriate referral - possible imaging.

Cornea

Transparent structure located in the anterior eye which is responsible for refracting (bending light). Clear structure which overlies the iris. Expected finding - clear - the entire iris should be visible beneath the cornea.

Blink Reflex

The cornea is composed of unmyelinated nerve endings which are very sensitive to light and touch. Blink reflex will result in a direct and consensual response (both eyes close). Assessing by brushing a cotton swab in the periphery of the patient's cornea checks the autonomic innervation of the eye. The ophthalmic branch of the trigeminal nerve CN V. Assess the efferent (motor) function of the orbicularis muscle (eyelid) innervated by the facial nerve CN VII.

Ocular Health Exam: Anterior Portion of the Eye

Slit Lamp & Gross Observation

Ocular Health Exam: Posterior Portion of the Eye

Slit Lamp with Specialized Lenses, Binocular Indirect Ophthalmoscope, Direct Opthalmoscope

Expected Findings for the Lips/Lashes (Anterior Structures)

-Symmetric Rt Eye vs. Lt Eye
-Smooth, uniform skin
-Clean without debris
-Complete lid closure with no exposure of the globe

Ptosis

Drooping upper eye lid - possible causes Horner syndrome, myasthenia gravis, superior eyelid or oribatl malignancy, congenital myogenic ptosis, cranial nerve III palsy. If it is acute onset ptosis with diplopia (double vision) - STAT REFERRAL.

Ectropion

Outward turning eyelid margin resulting in severe dry eye - mostly caused by aging - or less commonly CN VII palsy, cicatricial, mechanical

Entropion

Inward turning eyelid margin resulting in chronic irritation of ocular surface due to lashes rubbing on globe - mostly caused by aging - less commonly cicatricial (rare autoimmune sub-epithelial blistering disease) or mechanical.

Hordeolum

Acute infection of gland within eyelid typically caused by staphylococcus infection (tender and erythematous). Treat with warm compresses and consider oral antibiotics - Common infection of the eyelid and periorbital soft tissues - appropriate treatment of hordeolum will prevent chalazion development.

Chalazion

Chronic infection of the Meibomain gland (oil glands in the eyelid). Not tender or erythematous. Treat with incision and curettage or steroid injection.

Periorbital Cellulitis

"Preseptal" cellulitis, infection of the eye lid (anterior to the orbital septum) which typically results from local spread of an adjacent sinusitis. Eyelid erythema and edema without proptosis or restriction of extraocular muscles. Treat with oral antiobiotics - common infection.

Orbital Cellulitis

Infection involving the eyelid which involves structures posterior to the orbital septum commonly associated paranasal sinus infection or dental infection - acute eyelid erythema and edema and may include proptosis of the eye, restriction of extraocular muscles resulting in pain on eye movement, reduced vision, and possible pupil involvement. - EMERGENT ADMITTANCE TO HOSPITAL - broad spectrum antibiotics and Neuro consult.

Conjunctiva

Thin, translucent mucous membrane that covers the white part of the eye and the eyelids which contains superficial blood vessels.

Sclera

"White" part of the eye composed of thick, dense connective tissue

Acute Conjunctivitis

Characterized by conjunctival hyperemia. 3 types: Viral - "Pink Eye" with mild discharge. Allergic - Red eye with minimal discharge but severe symptom of pruitis (itch). Bacterial - red eye with moderate to copious discharge - RARE in adults.

Chronic Conjunctivitis

Characterized by red eye with associated discharge and inferior follicles that lasts for >4 weeks. (Must rule out chlamydial inclusion conjunctivitis - conjunctival and corneal cultures).

Pinguecula

Yellow-white, flat or slightly raised conjunctival lesion which does not invade the cornea, no treatment. Caused by sunlight exposure and chronic irritation.

Pterygium

Fibrovascular tissue arising from conjunctiva crossing onto cornea. Monitor until interfering with vision - surgical removal. Caused by sunlight exposure and chronic irritation.

Subconjunctival Hemorrhage

Characterized by blood underneath the conjunctiva which obstructs view of sclera. Often occur spontaneously due to valsava (forceful attempted exhalation against a closed airway) such as from coughing, sneezing, constipation, labor, etc. If recurrent, consider lab work up for clotting disorder. No treatment.

Episcleritis

Inflammation/engorgement of the episcleral blood vessels - commonly presents in a section of the conjunctiva in one eye. Mild to moderate tenderness. Most common etiology is idiopathic. Treat with artificial tears or topical steroid.

Scleritis

Inflammation/engorgement of conjunctival, episcleral, and scleral blood vessels which may be sectoral or diffuse. Patient may experience severe, boring eye pain that radiates to forehead and/or jaw. Commonly associated with rheumatoid arthritis. Treat with oral steroids.

Conjunctival Icetrus

Yellowing of the conjunctiva due to excessive bilirubin which causes the eyes to appear yellow. Common in premature infants, rare in adults. Treat jaudice/underlying systemic condition.

Corneal Abrasion

Epithelial defect (Stains with NaFI dye (yellow dye)) with history of trauma and absence of underlying corneal opacification. Red eye, watering, light sensitivity, and mild-severe pain relative to size. May consider prophylactic antibiotic and pain management.

Recurrent Corneal Erosion

Recurrent corneal abrasions - occurs in area of previous trauma. Most often occur upon wakening.

Corneal Ulcer

Focal white opacity - infiltration of white blood vessels with an overlying epithelial defect. Associated with red eye and discharge. t will complain of moderate-sever pain. Most common in contact lens users. Refer for treatment with topical antibiotics, may result in scarring and permanent vision loss.

Corneal Burn

Epithelial corneal damage which may progress to complete opacification due to foreign agent (alkali worse than acidic) which can progress to tissue necrosis. EMERGENT TREATMENT - rising eye for 30 minutes with saline and monitoring pH. Refer for prolonged management. DO NOT TRY to use an acidic agent to treat.

Iris

Colored part of the eye composed of two muscles responsible for controlling the size of the pupil. Expected findings - flat with uniform color throughout tissue, symmetric color Rt vs. Lt.

Aqueous Humor

Structure in the anterior chamber between the cornea and the iris. Should contain clear fluid.

Lens

Convex structure immediately posterior to the iris which is responsible for accommodation. Expected findings - clear without opacification.

Iritis

Inflammation of the iris characterized by WBCs and excess protein in the anterior chamber. WBCs are invisible to the naked eye. Associated conjunctival hyperemia and pt will complain of SEVERE PAIN and EXTREME PHOTOPHOBIA (extreme sensitivity to light). Associated with multiple autoimmune conditions. Treated with topical steroids and dilating agents.

Hyphema

Blood within the anterior chamber most commonly associated with severe ocular trauma - refer for eval and management.

Cataract

Opacification or clouding of the lens which causes reduced vision by blocking the amount of light entering the retina. Leading cause of blindness in the world. Most commonly associated with age however secondary cataracts can occur with various conditions or medications such as prolonged steroid use. Refer for cataract surgery.

Optic Nerve

Site where the nerve cells of the retina exit the eye to begin the visual pathway. Findings should have border of the optic nerve should be distinct, Rim of tissue of the optic nerve should be a pink color indicating good vascular perfusion, and the white center portion (the cup) should not occupy more than half the width of the nerve.

Glaucoma

Condition of progressive cell apoptosis of the optic nerve resulting in an increased C/D ratio (cup > 1/2 of disc). Second leading cause of blindness in the world. Can be associated with elevated intraocular pressure. Treat with topical medications to reduce intraocular pressure.

Papilledema

Swelling of both optic nerve heads characterized by the presence of blurred margins and associated retinal hemorrhages. By definition, papilledema is caused by an increased intracranial pressure - refer to Neuro.

Retina

Layer of neural tissue which contains blood vessels - Arteries appear lighter in color, overlie veins and are less in diameter. Veins are a deeper red color, lie beneath arteries, and have an increased diameter. Retina should be flat with a uniform "mottled" color appearance.

Hypertensive Retinopathy

Vasculopathy of the retinal blood vessels associated with hypertension. Signs include A/V crossings (compression of vein by overlying artery) and attenuation (narrowing) of the arteries. May progress to retinal hemorrhages and cotton wool spots (areas of ischemia0. Refer for retinal eval and treat underlying hypertension.

Diabetic Retinopathy

Vasculopathy of the retina secondary to uncontrolled diabetes. Signs include retinal hemmorrhages, cotton wool spots, venous dilation, exudates. Can cause permanent vision loss if progresses to neovascularization and/or macular edema. Leading cause of blindness in WORKING AGE adults in US - refer for retinal eval and treat diabetes.

Macula

Oval shaped area of the retina which contains the densest amount of cone photoreceptor cells (Cells responsible for vision). Area of the eye which is most responsible for central vision and visual acuity. Expected findings - darkened area within fundus which should appear uniform and flat.

Age Related Macular Degeneration

Degenerative condition of the macula which can result in deposition of lipid material called drusen (dry AMD); advanced macular degeneration can result in neovascularizaiton (wet AMD). Occurs in the elderly. Leading cause of blindness in the US it patients >60 y.o.