Ординатура / Офтальмология / Английские материалы / Practical Ophthalmology A Manual for the Beginning Ophthalmology Residents 4th edition_Wilson_1996
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anterior corneal surface from the side, and the reading is the anterior extent of the corneal apex on the gauge.
8.Obtain a similar measurement for the patient's left eye by using your right eye to align the appropriate vertical markers on the opposite mirror of the instrument.
9.Record the readings for each eye and the distance between the lateral canthi as shown below.
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Intercanthal Distance |
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16 itrim |
20 mm |
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Clinical Protocol 9.4
Measuring Globe Displacement
Horizontal Displacement
1. Imjagine a vertical straight line down the middle of the patients tace that aliens the center of the glabella and the philtrum of the upper lip.
2.Hold a millimeter ruler horizontally across the bridge of the patients nose, perpendicular to the imaginary vertical line (Fiqiire 1).
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3.Measure the distance from the center of the nasal bridge to the medial limbus of the right eye as the patient stares at a distance target. Occlude the contralateral eye if strabismus is present.
4.Repeat the measurement for the left eye. The difference between the two measurements is the amount of horizontal displacement.
Vertical Displacement
1.Hold a straightedge horizontally along the patient's nasal bridge to visually align the lateral canthi.
2.Hold a millimeter ruler vertically, perpendicular to the horizontal straight-
edge, to pass through the center of the pupil of the patient's right eye.
3.Measure the distance from the edge of the horizontal straightedge to the pupillary center (or corneal light reflex).
4.Repeat the measurement for the left eye. The difference between the two measurements is the amount of vertical displacement.
Clinical Protocol 9.5
Measuring Eyelid Position
Interpalpebral Fissure Height
1.Ask the patient to fixate a penlight in primary gaze position.
2.Hold a millimeter ruler vertically, close to the patient's open eye, to measure the distance between the center of the upper and lower eyelid margins (Figure 1).
3.Record the interpalpebral fissure height in millimeters for each eye.
To recheck the measurements, obtain and add together the following two measurements:
Figure 1
continued
a,. The distance between the upper eyelid margin and the corneal light reflex (normally about 4 mm; see below).
b. The distance between the lower eyelid margin and the corneal light reflex (normally about 6 mm).
Upper Lid Margin-Corneal Reflex Distance
1.Hold a penlight directly in front of the patient, so that the patient observes it in primary gaze and a corneal light reflex is present.
2.Use a millimeter ruler to measure the distance between the center of the upper eyelid margin and the corneal light reflex (Figure 2).
3.Record the margin-reflex distance for each eye. Use a nega-
tive number if the light reflex is
. obstructed bv the evelid.
Figure 2
Upper Lid Crease Position
1. Use a penlight or other near target to bring the patient's gaze into the primary position.
2. Measure the distance between the upper eyelid margin and the upper eyelid crease (Figure 3).
3. Record the upper lid crease position for each eye. Note if the upper eyelid crease is absent and cannot be accurately measured.
Levator Function
1. Either hold a thumb on the brow |
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or place the palm of your hand |
Figure 3 |
against the patient's forehead. |
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This maneuver prevents the |
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frontalis muscle from assisting with upper eyelid elevation, thereby isolating the action of the levator muscle.
2.Ask the patient to look down, and align the zero point of the millimeter ruler with the patient's upper eyelid margin, taking care not to actually touch the patient's lids or lashes (Figure 4A).
3.Do not move the ruler. Ask the patient to look up as far as possible. Keeping the ruler steady, measure the new location of the upper eyelid margin (Figure 4B). The difference between the two measurements (ie,
the total amount of upper lid excursion) gives the levator function.
4. Record the levator function in millimeters for each eye.
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Figure 4A |
Figure 4B |
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Clinical Protocol 9.6
Everting the Eyelid
To Examine the Lower Conjunctiva and Fornix
1.With the patient looking down, press the skin below the lower lid with your thumb or forefinger against the maxillary bone and tug down (Figure 1A).
2.Ask the patient to look up, which allows the lower fornix to prolapse and exposes most of the lower palpebral conjunctiva (Figure IB).
Figure 1A |
Figure IB |
To Examine the Upper Conjunctiva
Two-Hand Method
1.Using your thumb and forefinger to grasp some eyelashes, pull the upper lid margin away from the globe (Figure 2A).
2.Place an applicator stick horizontally at the upper lid crease, along the upper border of the tarsus, to act as a fulcrum (Figure 2B). Hold the applicator stick in the hand that is temporal to the eye being examined.
Figure 2A |
Figure 2B |
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BJH
3. Pull the upper lid margin outward and upward to fold the upper lid over the applicator stick (Figure 2C). Withdraw the applicator stick and hold the lid margin in place against the skin overlying the superior orbital rim with the thumb to view the upper tarsal conjunctiva (Figure 2D).
Figure 2C |
Figure 2D |
One-Hand Method
1. With the patient looking upward, use your hand that is temporal to the eye being examined and place your thumb against the lower lid to hold it in place (Figure 3A).
2. Place the tip of the index finger against the upper lid to hold the upper lid upwards and instruct the patient to look downward and to hold that gaze (Figure 3B).
Figure 3A |
Figure 3B |
continued
3.Pinch the upper and lower lids together, an action that should permit the upper lid to hang over the lower lid margin (Figure 3C).
4. |
Lay the side of your index fingertip across the upper lid just above the |
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upper border of the tarsus and push on the upper tarsal border. |
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5. Pinch the upper lid outward between your index finger and thumb |
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(Figure 3D). |
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Figure 3C
6. With finger and wrist rotation, flip the upper lid over to expose the upper palpebral conjunctiva. The index finger maintains a steady downward pressure on the upper lid crease as the finger is pulled away. The thumb provides the upward rotary action that turns the lid over. The thumb holds the upper lid margin in place against the superior orbital margin (Figure 3E).
Figure 3D
Figure 3E
To Expose the Upper Fornix
Manual Method
1.Evert the upper lid by the two-hand or one-hand method.
2.Firmly hold the upper lid margin against the superior orbital margin with your thumb.
3.With your free hand, use your forefinger to press the lower lid upward over part of the cornea and backwards against the globe. This action
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should compress die orbital contents sufficiently to cause most of the upper fornix to protrude.
Retractor Method |
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1.With the patient looking down, use your thumb and forefinger to grasp some eyelashes of the upper lid and pull the lid margin away from the globe.
2.With your free hand, place the edge of a lid retractor at the upper border of the tarsus of the upper eyelid, with the retractor handle facing down (Figure 4A).
Figure 4A |
Figure 4B |
3.Rotate die handle of the retractor upward and hold the retractor in place to view the upper tarsal conjunctiva (Figure 4B).
4.Continue to rotate the retractor and allow its curved end to press the cul-de-sac outward. This action everts the eyelid and exposes the upper fornix by suspending the upper lid on the
retractor (Figure 4C). Pressing |
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on the globe from below accen- |
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tuates the protrusion of the |
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upper fornix. |
Figure 4C |
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Estimating Anterior Chamber Depth
Flashlight With Diffuse Beam
1. While facing the patient, hold a penlight near the temporal limbus, and shine the light across the front of the right eye toward the nose. Keep the beam parallel to the plane of the normal iris.
2. Observe the medial aspect of the iris. Normally, the iris is completely illuminated (Figure 1A). An eye with a shallow anterior chamber will have two thirds of the nasal portion of the iris in shadow (Figure IB).
Deep |
Shallow |
Figure 1A |
Figure IB |
3.Grade the angle as open (grade IV or III), intermediate (grade II), or narrow (grade I).
4.Repeat the test for the left eye.
Flashlight With Slit Beam
1.Direct the slit beam perpendicular to the peripheral cornea.
2.View the anterior chamber angle at a 60° angle from the beam.
3.Grade the peripheral angle width by comparing the distance between the corneal endothelium and the iris with the corneal thickness. In an open angle, the peripheral chamber depth equals the corneal thickness. When the peripheral depth is one fourth or less of the normal corneal thickness, gonioscopy should be done to evaluate the angle.
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Clinical Protocol 9.8
Illuminating the Inner Eye for
External Viewing
Illumination Through the Sclera
1.In a darkened room, place the tip of the transilluminator against the eyelid. The light could also be held directly against the patient's anesthetized globe if the bulb is not hot.
2.Identify the red reflex, normally seen exiting through the dilated pupil and glowing through most of the sclera.
3.If a corneal opacity is present that obscures a clear view of the inner eye, note the shape of the pupil.
4.Look for a mass in the eye wall using transscleral illumination. Move the light source over the surface of the globe while examining the light reflected through the pupil and sclera. The pupil will be dark when the transilluminator is placed over a solid lesion. A solid lesion inside the eye wall will also obscure the faint scleral glow when the light is held against the adjacent or opposite sclera.
Illumination Through the Pupil
1.Shine a coaxial bright light, such as the direct ophthalmoscope, into the patient's eye from a distance of about 50 cm.
2.Look for any obscuration of the reflected light. Opacities near the pupillary axis appear as dark shadows at the pupillary plane against die normal red reflex.
3.Localize an opacity by asking the patient to look slowly up and down or by shifting the direction of the light; opacities visible against the red reflex will shift with eye movements according to their position relative to the pupillary plane (Figure 1). Determine which direction the opacity appears to move in relationship to the pupillary axis:
a.No movement. An opacity in the pupil, such as an anterior lens opacity, will remain stationary.
b.Same direction. An opacity anterior to the pupil (eg, in the cornea)
shifts in the same direction as the patient's direction of gaze.
c.Opposite direction. An opacity posterior to the pupil (eg, in the posterior lens or vitreous) shifts in the opposite direction.
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