Components of the Optometric Examination

eye's first refractive surface

cornea

aperture in the eye that varies in size to control the amount of light entering the eye (protects inner layer from damage)

pupil

colored muscle of the eye that can contract, controlling the aperture (pupil) in order to vary the amount of light entering

iris

eye's second refractive surface

lens

What are the two refractive surfaces of the eye?

cornea, lens

Which contributes the MOST refractive power to the eye: cornea or lens?

cornea

inside lining of the eye onto which light is focused

retina

area of the retina that generally contains the largest number of cones, where light is most focused

macula

most sensitive area of the retina, found in the macula, where light focuses best; contains largest number cones

**must be intact for good vision

fovea

Which photoreceptors are more sensitive to bright light: rods or cones?

cones

Are rods found in the more central or peripheral portion of the retina?

peripheral

Are cones found in the more central or peripheral portion of the retina?

central

nerve that gathers all the information from the retina and transmits it to the brain

optic nerve

How can you tell from a fundus image which eye you're looking at?

optic nerve is closer to the nose

smooth muscle of the eye that can contract to make the iris aperture (pupil) smaller in bright conditions

iris sphincter (muscle)

smooth muscle of the eye that can contract to make the iris aperture (pupil) larger in dim conditions

iris dilator (muscle)

tough, white, fibrous coat of the eye that serves as a protective layer around the eyeball

sclera

clear, cellophane-like mucous membrane lining the eyelids and covering the anterior portion of the sclera

conjunctiva

What happens in pink eye in regards to the conjunctiva?

conjunctival vessels are inflamed

demarcation between the sclera (with its conjunctival covering) and the cornea; border between sclera and cornea

limbus

What proportion of the eye's total refractive power is attributed to the cornea?

2/3

What proportion of the eye's total refractive power is attributed to the lens?

1/3

Even though the lens contributes less refractive power than the cornea, what makes it special?

it can vary its shape via accommodation

refers to the tightening of the ciliary muscle, allowing the lens to become more rounded for near vision

accommodation

If the eye is unaccommodated, is it prepared for distance or near vision?

distance

In accommodation, do the ciliary muscles relax or contract?

contract

In accommodation, do the zone fibers relax or tighten?

relax

In accommodation, does the lens get thicker or thinner?

thicker

When the eye is NOT accommodated, do the ciliary muscles relax or contract?

relax

When the eye is NOT accommodated, do the zonule fibers relax or tighten?

tighten

When the eye is NOT accommodated, does the lens get thicker or thinner?

thinner

What distinguishes between the front of the eye and the back of the eye? (i.e. serves as the landmark that separates the eye into anterior and posterior)

iris

refers to the lubricant of the eye surfaces

tear film

space between the cornea and the iris that contains aqueous

anterior chamber

fluid between the cornea and iris in the anterior chamber

**continuously made and drained

aqueous (humor)

gel-like fluid that fills the space between the lens and retina in the posterior segment of the eye

**ages, isn't continuously made and drained

vitreous (humor)

refers to the retinal vasculature - arterioles & venules within the layers of the retina that are visible inside the eye

choroid

portion of the back of the eye that you see with special instruments without dilating the pupil; you see the optic nerve, blood vessels, and the macula

posterior pole

What three things can you see when viewing the posterior pole through an undilated pupil?

optic nerve, blood vessels, macula

portion of the lining of the eye that you can see when you dilate the pupil; has less vasculature

peripheral retina

What does CEE mean?

comprehensive eye examination

CEEs evaluate what 3 important aspects of the eye?

optical, functional, ocular health

What does it mean to evaluate the optical aspects of the eye in a CEE?

determine any refractive errors

normal refractive condition of the eye in which light focuses on the retina normally; 20/20 vision OU

emmetropia

refractive error in which light entering the eye focuses behind the retina and the eye's focusing power is too weak

hyperopia

refractive error in which light entering the eye focuses in front of the retina and the eye's focusing power is too strong

myopia

Why do we correct hyperopia with + power lenses?

increase the too weak focusing power

Why do we correct myopia with - power lenses?

decrease the too strong focusing power

What does it mean to evaluate the functional aspects of the eye in a CEE?

check for appropriate eye tracking, eye teaming, and eye focusing

general term that refers to eye strain; occurs when the eyes don't point correctly at a target or the focusing system doesn't work correctly; causes blurred vision after prolonged work, double vision, eyestrain, and headaches

asthenopia

What does it mean to evaluate ocular health in a CEE?

check for anatomical defects or medical conditions

What are two examples of systemic medical conditions that affect the eye that may be detected in a CEE?

hypertension, diabetes

What are the 5 components of a comprehensive eye examination?

case history, entrance testing, refraction, near testing, ocular health

Why is taking a patient's case history an important first step of a CEE?

so you can learn of current medical problems that may affect the eye or past eye and vision problems

After completing the case history, the doctor may choose to follow the standard testing as part of a CEE, called what?

database

After completing the case history, the doctor may choose to evaluate the patient's visual system by focusing on areas that may need more than a routine evaluation, called what?

problem focused testing

The doctor thinks of a patient's problems in terms of ____ ____; the doctor develops a list of possible causes for the patient's concerns/symptoms. The CEE that follows then attempts to identify the cause of the patient's symptoms.

differential diagnoses

Why do optometrists perform entrance (screening) tests?

quickly provide general information about a patient's visual system to assess whether each component functions properly

What are 8 different entrance tests in a CEE?

visual acuity, pupil testing, cover test, version system, confrontation visual field, color vision, stereopsis, near point of convergence

entrance test that evaluates the resolving ability of the eye

visual acuity

What does sc mean?

without correction

What does cc mean?

with correction

What do you do immediately after the case history but prior to any other testing?

visual acuity

How do you evaluate visual acuity for a new patient?

**For insurance purposes, if a patient has not been to your office in more than three years, you can bill the encounter as a new patient

unaided and aided at distance and near

How do you evaluate visual acuity for an established patient?

aided distance and near

How do you evaluate visual acuity for a patient returning for follow-up care (f/u)?

**less than 1 year since a CEE

aided distance vision only

entrance test that evaluates the ability of the eyes to respond to a light stimulus (part of the eye health screening)

pupil testing

What three things does a doctor assess in pupil testing?

pupil size, shape, and ability to react to light

test that compares the pupil response to light in one eye to the other eye

Marcus Gunn (test)

When do you perform pupil testing? CEE or f/u? New or existing patient?

every visit

(all of those listed)

entrance test that evaluates the ability of the two eyes to point at a target simultaneously; tests eye alignment (part of functional vision screening)

cover test

Is the cover test done with correction?

yes

If a patient is presenting for a CEE, how do you perform the cover test?

distance and near

If a patient is presenting for f/u care, how do you perform the cover test?

distance only

entrance test that evaluates the ability of the eye muscles to move the eyes in different positions of faze and also to track a moving target (eye health screening)

version system

When do you perform version system testing? CEE or f/u? New or existing patient?

every time

(all of those listed)

entrance test that evaluates peripheral (side) vision (central visual field)

confrontation visual field

Is confrontation visual field performed with correction?

no

When do you perform confrontation visual field?

every visit unless patient is returning for automated visual field test

Is color vision testing performed with correction?

yes

(best near correction)

What is the doctor usually screening for with color vision testing?

congenital, genetic color vision deficiencies

Do inherited color vision deficiencies usually indicate a problem with eye health?

no

When do you perform color vision testing?

only for new patients

entrance test that evaluates depth perception - the ability of the two eyes to simultaneously point at the same location and the brain's ability to combine the two things into one

stereopsis

Is stereopsis testing performed with correction?

yes

(best near correction)

When do you perform stereopsis testing?

only for new patients

entrance test that evaluates the ability of the eyes to move inward or outward in a coordinated manner; test the ability of the two eyes to track an object toward the face while maintaining a single image

near point of convergence

When do you perform testing for near point of convergence?

every pediatric visit, only if adults complain

Ultimately, what is the goal of entrance testing?

to help you refine your original differential diagnoses

(for example, a 65 y/o presents with blurry vision, and you might initially think that they need a different Rx or have cataracts, but the entrance test might reveal visual field loss, which isn't caused by refractive error or cataracts)

What are the 4 methods of refractive testing?

lensometry, keratometry, retinoscopy, manifest (subjective) refraction

term for right eye

OD

term for left eye

OS

term for both eyes together

OU

refractive testing technique that measures the power of a spectacle correction

lensometry

instrument used to manually focus a pattern (mire) to determine the power of a lens

lensometer

two terms for refractive testing technique that measures the curvature of the cornea

keratometry, ophthalmometry

instrument that measures the curvature of the cornea and thus provides information about both refractive and ocular health aspects of a patient's eye

keratometer

The curvature of the front of the eye, determined with keratometry, gives you information about what condition?

**with this, there is not a single point of focus of light in the eye, so everything is a blur

astigmatism

A keratometer may give measurements such as 43.75 @ 165 and 44.62 @ 075. What does that mean?

if the two numbers are different, this means there is astigmatism to some degree

condition in which the surface of the eye is abnormally thin in the center, resulting in a cone-shape

this disrupts the cornea's ability to act as an accurate refractive surface and can cause the cornea to scar, which disrupts the clarity of the surface

keratoconus