Welch Allyn 18200 Bedienungsanleitung Seite 12

3. To help decide amplyopic therapy;
4. To determine the adequacy of
cyclopegia.
For more information on Dynamic
Retinoscopy, read the following:
Guyton, D.L., O'Connor, G.M.: Dynamic
Retinoscopy, Current Opinion in
Ophthalmology 1991, 2:78-80.
Locke, L.C., Somers, W.: A Comparison
Study of Dynamic Retinoscopy Techniques.
Optom Vis Sci 1989, 66:540-544.
Mazow, M.L., France, T.D., Finkleman,
S., Frank, J.: Acute Accommodative and
Convergence Insufficiency. Trans Am
Ophthalmol Soc. 1989, 87:158-173.
SPIRALLING—Spiralling is a method for
estimating ametropia without lenses. This
can be helpful in determining the starting
point for lens introduction when working with patients who have a
high unknown ametropia. The Welch Allyn No. 18200 streak
retinoscope is particularly well suited for this technique because the
instrument maintains the same focal plane during streak rotation.
CROSSED LINEAR POLARIZING FILTER—A crossed linear
polarizing filter can be engaged by moving the sliding switch on the
practitioner's side of the instrument from the down to the up position
(see Figure 9). This filter cuts down on reflections and allows
retinoscopy to be performed closer to the axis of the correcting lens.
SPOT RETINOSCOPY—The Welch Allyn No. 18200 streak
retinoscope can be converted to a spot retinoscope by simply
changing the lamp. In recent years the spot retinoscope has been
largely supplanted by the streak but there are some practitioners who
still favor the spot retinoscope.
10
Figure 9