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: Abduction
Bielschowsky 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