Clinical Skills Flashcards
Keratometry
To determine the corneal curvature and record the result
Procedure
Focus the eyepiece
Instruct patient
Position the patient
Position Keratometer
Adjust mires (complete 1 through 4 below in any order)
Focus the mires
Rotate the drum
Superimpose (place or lay (one thing) over another,) the plus signs
Superimpose the minis signs
Record results (complete 1 through 4 in any order)
Record the horizontal knob (diopter) reading
Record the horizontal drum (meridian) reading
Record the vertical (diopter) knob reading
Record the vertical drum (meridian) reading
Ocular Motility
Phoria
Strabismus
Tropia
Phoria
The tendency for an eye to deviate from straight ahead. Are not discernible with both eyes open, but only when one eye is covered. In esophoria (inward eye turn), if the patient is asked to fixate on a distant target, the eyes will fix normally-they will be straight. If one eye is covered, it will turn in towards the nose. When the occulder is removed, the eye will fixate normally. prefixes are used to denote the direction of such deviation (e.g., esophoria, exophoria (our eyes tend to drift outward or one eye drifts away from the other), hypophoria (one eye to deviate downward), hyperphoria (the eye points upwards, but not permanently). Contrast with a trope. In esotropia (an inward turning of the eye and is the most common type of strabismus in infants), the eye will turn in whether covered or uncovered.
Strabismus
The condition where binocular fixation is not present, i.e., the foveal line of sight of one eye fails to intersect the object of fixation. Observed as a deviation, one eye out of alignment with the other eye, Sometimes referred to as “squint.” Often due to muscle imbalance and sometimes classified by type, e.g., convergent (coming closer together), divergent (going in different directions), alternating or vertical. Synonyms are squint, cross-eye, and heterotropia (he eyes don’t look in exactly the same direction at the same time).
Tropia
A type of strabismus. Any persistent deviation from normal of the axis of the eyes. When used with a prefix it denotes the type of strabismus (e.g., hypertrophic, esotropia, exotropia).
Ocular motility
To asses the patients for a tropia or phoria and record results
Ocular Motility Procedure
Instruct patient
Observe eye alignment
Perform cover-uncover test/cross-cover test
Cover-uncover technique
Cover fixated eye
Observe non-fixated eye
Observe fixated eye
Uncover non-fixated eye (tropia)
Cross-cover technique
Cover right eye
Observe right eye as cover is moved to the left eye
Observe left eye for movement as cover is moved to right eye
Repeat this several times to break the patients fusion (phoria)
Record results
Record type of deviation (tropia or phoria)
Record direction of deviation
Actions of the extra ocular muscles: Medial rectus Lateral Rectus Superior Rectus Inferior Rectus Superior Rectus Inferior Oblique
Medial Rectus
Primary: Adduction
Secondary: None
Tertiary: None
Lateral Rectus
Primary: Abduction
Secondary: None
Tertiary: None
Superior Rectus
Primary: Elevation
Secondary: Adduction
Tertiary: Incyclotorsion (inward torsional movement of the eye)
Inferior Rectus
Primary: Depression
Secondary: Adduction
Tertiary: Excyclotorsion (outward, torsional (rotational) movement of the eye)
Superior Oblique
Primary: Incyclotorsion
Secondary: Depression
Tertiary: Abduction
Inferior Oblique
Primary: Excyclotorsion
Secondary: Elevation
Tertiary: AbductionBielschowsky Head Tilt Test
aka. Bielschowsky Three-Step Test
Primary position, all four muscles affect the vertical balance of the eyes, but the muscles each have several actions which vary depending on the position of the eye. A weakness of any one of these muscles may result in a vertical muscle imbalance, but because of the many muscles involved and their various actions, it is sometimes difficult to determine which muscle is paretic.
The vertical muscles have a different effect depending on the position of the eye. The rectus muscles have their strongest effect when the eye is abducted, the obliques have their strongest effect when the eye is adducted. These muscles have torsional actions that compensates for head tilting. Intorsion occurs when the 12 o’clock of the eye rotates towards the nose, and extortion occurs when the 12 o’clock position rotates away from the nose.
If a patient has a vertical muscle imbalance, measuring the imbalance in positions that help to isolate the actions of the muscle helps identify the paretic muscle. Therefore the vertical imbalance is measured in left and right gaze, and with left and right head tilt.
The muscle that is circled three times at the end of the test is the paretic muscle.
Bielschowsky Example
Step 1: assume the patient has a right hypertrophic. This could be due to weakness of the muscle that depress the right eye, or a weakness of the muscles that elevate the left eye. The first step is to circle those muscles
Step 2: Nest have the patent look to the right and to the left. The patent reports diplopia is greater with left gaze. Circle the muscles that have their greater effect in that field of gaze.
Step 3: The last step is to determine if the hypertrophic is greater with right or left head tilt. The patient reports it is greater with right head tilt. Circle the muscles with the greatest effect in that position.
The muscle that is circled three times is the paretic muscle.
Ocular patching
To protect the eye following surgery, injury, or as a therapeutic measure, e.g., a “pressure patch”
Ocular patching contraindications
Penetrating injuries, blunt trauma, corneal ulcers, corneas suffering from contact lens related abrasions or chemical burns. A shield may be a better choice for these patients.
Ocular patching procedures
Open both sterile eye pads
Tear four to five pieces of tape each measuring 4-5 inches
Clean around the eye if necessary, e.g., skin is too oily for tape to adhere (especially forehead and cheek area) with either sterile saline or an alcohol pad (depending on the patient’s kin sensitivity)
Instill any required drops or ointments as directed by physicians
Ask patients to close both eyes
Fold one of the sterile eye pads in half over the closed eye while holding it in place
Place the remaining sterile eye pad over the folded one
Apply the 1st piece of tape firmly in an oblique position to the forehead and continue to the cheek (to prevent blinking of further injury to the eye)
Use remaining pieces of tape to secure the eye pad into place; take care not to get the tape near the mouth or jaw area.
Ocular shield
To protect the eye after penetrating injuries, blunt trauma, lacerations to the eyelids, chemical burns, contact lens related abrasions, or following surgery
Ocular child Procedure
Tear several pieces of tape each measuring 4-5 inches
Clean around the eye if necessary, e.g, skin is too oily for tape to adhere (especially forehead and cheek area) with either sterile saline or an alcohol pad (depending on the patient’s skin sensitivity)
Instill any required drops or ointment as directed by physician
Ak patient to close both eyes
Apply shield at an angle (if plastic with tip up pointing toward forehead)
Apply tape securely over the eye in an oblique position securing the shield into place
Lensometry
To neutralize a designated lens distance prescription and bifocal add. Choose to work in plus (+) or minus (-) cylinder.
Record results.
Lensometru Procedure
Focus the eyepiece
Position the spectacle on the stage
Adjust axis dial until lines are continuous (without skewing)
Adjust power drum spherical power (diopter dial), note the power reading 1 9diopter dial)
Adjust the power drum (diopter dial), note the power reading 2 (diopter dial)
Calculate cylinder power
Reposition lens for bifocal
Adjust power drum (diopter dial), note the bifocal reading
Calculate bifocal add power
Record results
Instilling ocular drops and ointments
To administer medications for diagnostic and/or therapeutic purpose
Instilling ocular drops and ointments procedure
Wash hands prior to drop instillation
While patient is seated in exam chair, instruct then to tilt their head up slightly while looking upward toward the ceiling or other fixation object; encourage the patient to keep both eyes wide open
Gently pull down the lower eyelid, exposing the lower palpebral conjunctival culture-de-sac, and instill the drop into pocket you have created, taking care not to touch the tip of the dropper to the eye.
Ask the patient to close both eyes gently, eliminating any squeezing or wiping
When instilling an anesthetic drop, instruct the patient to look down while lifting their top eyelid and placing the drop on the superior sclera (12 o’clock position), as this allows for an even distribution of the anesthetic over the cornea and will result in better comfort to the patient.
When using multiple drops, be sure to wait 2-5 minutes between each to allow for proper absorption
When applying an ocular ointment, place a small amount (approximately 1/4”) in the lower cul-de sac as the patient looks up, taking care not to touch the tip of the tube to the eye.
Visual fields
To determine the area and extent of a patient’s vision and record results.
Perimeter
Perimetry
Peripheral Vision
Perimeter
Any instrument used for measuring the angular extent of the field of vision peripheral to the point of fixation
Perimetry
The test for the determination of the extent of a person’s visual field; typically utilized to diagnose a problem in the visual pathway
Peripheral Vision
The extent of vision outside the direct line of sight, i.e., the ability to perceive the presence, motion, or color of objects in the outer filed of vision
Visual field procedure: Confrontational Visual Field Exam (fully manual)
The examiner and patient mist sit approximately 3 feet apart
The examiner must present targets exactly half way between themselves and the patient
Instruct the patient to cover or close one eye and look straight ahead
Instruct the patient to continue to look straight ahed at the examiner while at the same time observing the examiner’s hand
Move hand and instruct the patient to indicate when they are just unable to see it (i.e., back into the patient’s visual field)
Move hand back and instruct the patient to indicate when they are just unable to see it (i.e., bak into the patient’s visual field)
Repeat for all quadrants
Repeat for the other eye
A confrontational test is easy and typically a screening test.
Visual field procedure:Perimetry (manual with aid of an instrument, e.g., tangent screen or Goldman)
Tangent screen:
The tangent screen normally has a black felt background; there is circular stitching every five degrees, allowing for testing out to thirty (30) degrees at one meter; additionally there is normally radial stitching that starts at the 180 meridian running through the fixation point every 22.5 degrees.
Position the patient approximately 3 feet from a dark screen background
Instruct the patient to cover one eye and continuously look a the center target on the dark screen
A small object is moved from outside the patient’s visual field towards the patient’s visual field
Instruct the patient to signal when the small object comes into view
Map the results
Repeat for the second eye
Goldmann
Another alternative; refer to an instruction manual for this equipment.
Visual Field Procedure: automated perimetry exam-fully automated.
Generic; refer to the owner’s instruction manual for the specific instrument utilized
Place the patient comfortably in front of the instrument’s concave dome
Properly align patient and cover one eye
Used appropriate spectacle correction as needed, taking care to place sphere power closest to patient’s eye
Instruct the patient to continuously look at the center target
Explain to the patient that a computer program will shine various lights in different areas of the dome
Instruct the patient to click a button whenever one of these lights is seen
Inform the patient that when the lights stop being presented that the computer will map and calculate the visual field
Repeat for the second eye.
Amaurosis
Anisocoria
Miosis
Partial or total blindness form any cause; also, blindness occurring without noticeable change in the eye, such as from critical cause, hysteria, intoxication, etc.
Refers to the condition in which the pupil of the eyes are not equal in diameter
Refers to ruction in pupil size and sometimes the condition of having a very small pupil, e.g., under normal illumination, a pupil 2 millimeters or less in diameter.
Miotic
Mydriasis
Mydriatic agent
Any drug that causes the pupil to contract
Refers to an increase in pupil size and sometimes the condition of having an abnormally large pupil, e.g., under normal illumination a pupil 5 millimeter or greater in diameter
Any drug that dilates the pupil
Pupil
Tonic pupil
The opening in the iris that allows light to reach the retina; the size of the pupillary aperture is controlled by the sphincter muscle of the iris; under normal illumination a human pupil ranges from 2 to 5 millimeters in diameter.
A pupil that does not respond to light nor move with accommodation.
Swinging Flashlight Test
To measure the size and reaction to light of the pupil and record results
Used a pupillometer to measure the pupil size
To measure pupil response:
Use a strong, steady light
Shine the light into one eye, and then quickly switch to the other
Repeat back and forth
Normal Response lo light directed at the pupil–> Both pupils contract equally
Relative Afferent pupil defect (RAPD) Test
A reliable way to implicate or rule out optic nerve and/or retina disease
Based on the principle that light in one pupil causes both pupils to constrict
Note that if both eyes are equally dysfunctional, no relative defect would be found
Use the shining flashlight test:
When light is directed into the unaffected eye, both pupils constrict
Shifting the light to the other eye, the affected eye will also transmit light but to a lesser and slower degree than the unaffected eye.
The brain interprets this as decrease of light being presented to the eye.
The neutral response Is to dilate both pupils in order ro let more light enter, note that this dilation occurs in both eyes, even though only one eye is being affected; this is RAPD.
Record any RAPD.
Abnormal Pupils
Acute glaucoma Adie's pupil Argyll Robertson Pupil Constricted pupil Horner's Syndrome Relative Afferent Pupillary Defect (RAPD)
Acute glaucoma
Elevated IOP; and pupil is mildly dilated and poorly reactive
Adie’s pupil
A pupil with sluggish response to light (efferent defect)
Argyll Robertson Pupil
A pupil characterized by the loss of reflex to direct and consensual light, but with normal contraction upon accommodation and convergence and others normal vision; often present in neurosyphilis (syphilis (A bacterial infection usually spread by sexual contact that starts as a painless sore) of the central nervous system)
Constricted pupil
Could result from iritis or drug induced.
Horner’s Syndrome
Mild ptosis of the upper lid with retraction of the lower lid, constricted pupil; pupillary size difference more noticeable in dim light (efferent defect) and anhydrosis (decrease sweating on the affected side)
Relative Afferent Pupillary Defect (RAPD)
aka. “Marcus Gun” (MG) pupil when on optic nerve conduction defat is present and both pupils dilate somewhat when the abnormal eye is stimulated; compared to the constriction following stimulation of the normal eye.
Record pupil exam as follows:
OD 3/3+ OS 3/3+ -MG or RAPD
Anisocoria example
OD 2/3+ OS 3/3+ -MG or RAPD (Bright)
OD 4/3+ OS 5/3+ -MG or RAPD (DIM)
1mm difference present in both bright and dim
Aqueous Humor
Application
Tonometer
The clear, watery fluid that fills the anterior and posterior chambers of the from part of the inner eye; important for the nutrition and metabolism of the cornea and crystalline lens.
The flattening of a convex surface; application tonometry flattens the cornea for measurement of intraocular pressure.
An instrument for determing intraocular pressure (IOP)
Tonometry
To measure intraocular pressure or IOP (the fluid pressure in the eye, which is determined by the difference in aqueous humor production and aqueous humor drainage through the trabecular meshwork); and record results.
Tonometry Procedure
Instruct patient administer anesthetic Instill Fluorescein Position prism shaft Position tonometer Adjust tonometer to patient Position cobalt blue filter Adjust slit lamp beam intensity and length Position the light source Position the prism tip Applanate the cornea Position the mires Take pressure Record the pressure reading Note: using the application tenement, if the corneal astigmatism is greater than 3 diopters, position the prism axis of the minus cylinder at the red mark on the prism holder)
Retinoscopy
An objective method to determine the optical correction of the patent. Choose to work in plus (+) or minus (-) cylinder and record result
Retinoscopy Procedure
Position the phoropter Level the horopter Clear cylinder and spare dials Fog eye not being tested Record workin distance Instruct the patient Turn on retinoscope Adjust sleeve position Adjust the room lights Look through peephole Shine light into patient's eye Sweep light across the pupil Determine reflex Identify principle meridian Determine the sphere power Set the second meridian; sweep light along second meridian Determine the axis Determine the cylinder power Remove working distance Record results
Refinement
A subjective method to determine the optical correction of the patient and can follow objective Retinoscopy. Choose to work in plus (+) or minus (-) cylinder and record results.
Refinement Procedure
Choose starting point (from auto refractometer, retinoscopy, present glasses lensometry reading, etc.) Instruct patient Occlude the untested eye Refine the sphere poweer Put cross cylinder in place Adjust cross cylinder to measure axis Refine the cylinder axis Adjust cross cylinder to measure power Refine cylinder power Calculate adjusted sphere power Remove cross cylinder Re-refine the sphere Assess visual acuity Record Results
Retinoscope
An instrument for objectively determining the refractive state of the eye utilizing the retinal reflex.
