This examination is used to ascertain which part of the retina of the deviating eye the image of the fixated point falls on. The patient looks through a special ophthalmoscope and fixates on a small star that is imaged on the fundus of the eye. The examiner observes the fundus.
❖ In central fixation, the image of the star falls on the fovea centralis.
❖ In eccentric fixation, the image of the star falls on an area of the retina outside the fovea (Fig. 17.10). Usually this point lies between the fovea and the optic disk.
Aside from the type of fixation, one can also estimate potential visual acuity. The greater the distance between where the point of fixation lies and the fovea, the lower the resolving power of the retina and the poorer visual acuity will be. Initial treatment consists of occlusion therapy to shift an eccentric point of fixation on to the fovea centralis.
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