clinical opt midterm 1

Exophthalmos (Proptosis)

protrusion of eye outwards

Enophthalmos

eye sunken inwards

Ptosis

droopy eyelid

Ectropion

eyelid turned out

Entropion

eyelid turned inwards

Subconjunctival hemorrhage

bloody eye

Epiphora

tearing/watery eye

Miosis

constricted pupils, common with age

Hippus

bilateral rhythmic oscillations of pupil regardless of light intensity

Consensual pupillary reflex

pupils constrict equally and in sync

Swinging flashlight test

diagnosis for RAPD

Trace RAPD

initial constriction followed by quick dilation

1–2+ RAPD

no change followed by dilation

3–4+ RAPD

immediate dilation during swinging flashlight test

RAPD results in

VA loss, loss of color vision, blind spot in VF, headaches

Anisocoria

Unequal pupil diameters with equal difference between pupil diameters in bright and dim light

20%

Percentage of the normal population with anisocoria

0

4 mm

Horner’s syndrome

Pupil size difference greater in dim light than in bright light (not consistent)

Horner’s syndrome symptoms

Ipsilateral anhydrosis, ptosis, and miosis

Horner’s syndrome sign

Apparent enophthalmos

Horner’s syndrome cause

Pancoast tumor affecting sympathetic cervical ganglia

Medial rectus

Adduction

Lateral rectus

Abduction

Inferior rectus

Depression

Superior rectus

Elevation

Superior oblique

Intorsion

Inferior oblique

Extorsion

Oculomotor nerve (CN III) innervates

Levator palpebrae superioris, Medial rectus, Inferior rectus, Inferior oblique, Superior rectus

Trochlear nerve (CN IV) innervates

Superior oblique

Abducens nerve (CN VI) innervates

Lateral rectus

Ductions

Movements of one eye

Versions

Conjugate movements of both eyes together

Levo-

Left

Dextro-

Right

Dextro-depression version

Looking to the right and down

Vergence

Disjugate eye movements (eyes move opposite directions)

Convergence

Both eyes move nasally to look up close

Divergence

Both eyes move temporally to look at distance

Yoked muscles

Equal innervation of eye muscles, one motor command split between both eyes

Vertical rectus insertion angle

20°

Oblique muscle insertion angle

50°

EOMs test

Investigates integrity of oculomotor innervational balance

Retinal image motion

Prevents neural blur of images

Foveal vision

Highest resolution vision is found in our fovea

Vestibulo-ocular reflex

Stabilizes vision and allows humans to maintain good vision while head is moving

Optokinetic nystagmus

Pursuit/saccade movements: slow eye movement followed by quick reset

Saccades

Fastest eye movement, conjugate and quick shift of gaze direction

Pursuits

Smooth conjugate movement of the eyes that is partly reflexive and attentive

Static perimetry

Confrontation visual field considered what type of visual field test

Temporal lobe

“Pie in the sky” visual field defect

Parietal lobe

“Pie on the floor” visual field defect

Occipital lobe

Macular sparing (intact central vision) visual field defect

Quantitative visual field testing

Conducted for glaucoma patients

Static perimetry

Visual field test with non-moving target

Kinetic perimetry

Visual field testing with moving target

Problem-based screening

Suspect a problem in patient, test to rule out

Optic chiasm lesion

Causes a heteronymous visual field defect

Static threshold perimetry

Visual field test to find the limits of vision

0

25 (60-RE)

RAPD OD only

If optic nerve is damaged OD

Optic tract lesion

Homonymous visual field defect losing entire same side of visual field

Optic nerve lesion

Entire loss of visual field in one eye

Purpose of VA test

Check visual fixation and measure resolving power of the foveal area

VA testing chart illuminance

85%

VA increases as background luminance increases

Snellen chart

Different number of optotypes per row and irregular progression in letter size

Bailey-Lovie chart

Different number of optotypes per row and irregular progression in letter size are disadvantages

Feinbloom chart

5 letters per line, used in low vision, starts at 10 ft

Lighthouse continuous text

Used for measurement of reading acuity

Ideal pupil size for measuring distance VA

Between 2

Eccentricity

Light entering farther from fovea increases

Infants develop 20/20 vision

6 months old

Pinhole use

When best corrected VA is 20/30 or worse

VA increases with pinhole

Possibly uncorrected RE or corneal abnormalities

VA decreases/stays the same with pinhole

Suspect pathological changes

Legal blindness

Best corrected VA is 20/200 in patient’s best eye

M-units

Units used to measure near vision, primarily for low vision

Reduced Snellen

Most common test for near VA, measured at 40 cm

Accommodation

Ability to focus

Luminance

Light coming from the chart

Orthophoria

No movement of the eye

Phoria

Latent deviation of the eyes

Tropia

Manifest deviation of the eye

Exotropia (XT)

One eye resting outwards

Esotropia (ET)

One eye resting inwards

Hypertropia

One eye rests upwards

Unilateral cover test

Checks for tropia

Alternating cover test

Checks for phoria and magnitude

Fusion (binocularity)

What the alternating cover test checks

Objective cover test

Type of cover test

Cover test distance

Distance and near

Morgan’s expected phoria at distance

Ortho to 2 prism diopters

Morgan’s expected phoria at near

Ortho to 6 prism diopters

Strabismic amblyopia

Caused by misalignment of eyes leading to suppression of one eye

Refractive amblyopia

Caused by unequal refractive errors, brain favors eye with better focus

Deprivation amblyopia

Caused by obstruction of vision in one eye (e

Base in

Prism base placement for an eye that is kicking in

Base down

Prism base placement for latent deviation downward

Frequency C

Patient has constant tropia