Outline
Station 1: SCLERAL INDENTATION
I. Purpose
1) Examine the peripheral fundus by inwardly displacing tissue - allowing a view of
the peripheral retina in profile
2) Allow stereoscopic examination of peripheral retina
3) Change the perspective with which the retina is viewed
4) Enhance the contrast between normal and abnormal retina
II. Indications
1) Symptoms of retinal detachment
2) History of blunt trauma
3) High axial myopia
4) Aphakia
5) Retinal anomalies: holes, breaks, lattice, vitreo-retinal adhesions
6) Evaluating abnormalities in the peripheral retina
III. Contraindications
1) Recent intraocular surgery
2) Recent hyphema
3) Recent or suspected penetrating injury or ruptured globe
IV. Instrumentation
1) Binocular indirect ophthalmoscope (BIO) and condensing lens (e.g., 20D)
2) Topical ophthalmic mydriatic solution
3) Scleral depressor (e.g., double-ended flat, thimble, cotton-tipped swab)
V. Technique
1) Preparing the patient: maximal pupillary dilation and patient reclined
2) Perform BIO in area of interest (note landmarks)
3) Doctor holds depressor with the “leading” hand
4) Place depressor on the lid furrow/crease
5) Patient slowly looks in the direction of the depressor, allow the tip of the depressor
to follow the eye back into the orbit. The tip of the depressor should be tangential
to the globe and should be approximately 7-14 mm posterior from the limbus.
6) The depressor, the patient’s gaze and examiner MUST be along the same axis;
the examiner’s eyes must be 180 degrees away from the patient’s gaze and the
depressor.
7) Place condensing lens in position to view the retina
8) Apply gentle pressure to the depressor
VI. Procedural trouble-shooting:
1) Pain caused by:
- depressing the tarsal plate
- depressor not placed tangential to the globe and pressing too much towards the
bony orbit or the globe
2) Examiner can’t visualize the depressor:
- Alignment: Are the depressor, the patient’s eye and the examiner’s head
aligned?
- Depressor location: Is the depressor “sunk” (7-14 mm) behind the limbus?
- BIO view: Is the doctor viewing out to or near the ora?
VII. Review of common peripheral retina findings utilizing video and stereo slides
- Lattice
- Rhegamatogenous retinal detachment
- Retinoschisis
- Retina holes
- Vitreo-retinal tuft
Station 2: RETINAL 3-MIRROR
I. Purpose/Indications:
1) Stereoscopic examination of the retina
2) Often performed after binocular indirect ophthalmoscopy for a closer look at
specific areas on the retina
II. Contraindications
1) Recent intraocular surgery
2) Recent hyphema
3) Recent or suspected penetrating injury or ruptured globe
III. Instrumentation
1) 3-Mirror fundus contact lens
2) Slit lamp biomicroscope
3) topical ophthalmic anesthetic solution
4) topical ophthalmic mydriatic solution
5) cushioning solution
IV. Technique
1) Patient preparation
2) Lens preparation
3) Set-up of slit lamp: magnification at 10x; beam width at 3-4 mm; light tower in
straight-back position
4) Lens insertion
5) Move slit lamp forward, keeping beam centered in the middle lens until posterior
pole is in focus
6) Rotate the mirror 180 degrees from lesion of interest and move beam to mirror
7) Lens removal
V. Parts of the retina viewed with the 3-Mirror:
1) Anterior (A) Mirror - the semicircular mirror: ora serrata/pars plana, including
vitreous base
2) Peripheral (P) Mirror - the trapezoidal mirror: equator to ora serrata
3) Equatorial (E) Mirror - the rectangular mirror: equator
4) Center Lens: central 30 degrees of the posterior pole
VI. Clinical Tips:
1) Get a view through the central lens, E or P mirror first, since these are the easiest
to use.
2) To get a view through the A mirror, you must see the red retinal reflex before you
can visualize the anterior retina. Try tilting the lens to get the red reflex.
3) Once the retina is in focus for any of the mirrors, it will be very close to in focus for
all of them.
4) One can extend the view of a lens by tilting the mirror or if the patient moves his or
her eye.
- More anterior view: tilt lens toward mirror or patient looks toward area viewed.
- More posterior view: tilt lens away from mirror or patient looks away from area
viewed.
VII. This hands-on wet lab will allow participants to practice both scleral
indentation and retinal 3-mirror ophthalmoscopy on each other (one eye dilated)
with the benefit of teaching tubes and video.