Saturday 17 January 2009

Orthoptic Exercises

1. Fusional Reserve Exercises

Treatment of choice for exo-deviations up to 20D. The ability to converge at the relevant distance is trained, the positive fusional reserves. Training negative fusional reserves is more difficult but can produce good results.

2. Free-Space Techniques

The fusion of two stereo pairs by over/under converging in free space. First px needs to have physiological diplopia demonstrated with two large targets (eg two pencils). If the px can't see the two targets then gross suppression is indicated. If px is only heterophoric this can easily be broken down. Following this the px can progress to exercises like the three cats. This exercise can be used in both exo and eso deviations. If BV is present at one fixation point then theoretically it should be able to be achieved at all distances.

3. Near to Far Tracking

Pen to nose exercises. Take care as fusion isn't always achieved but px doesn't report the diplopia due to suppression.

4. Step Vergence

Introduce prism before the eyes while patient fixates a target - introducing disparity and the vergence system is stimulated to retain fusion. The prism is then removed when fusion is established. A series of repetitions are performed to strengthen fusion.

5. Sliding Vergence

A target is fixated w/a variable prism stereoscope or risley prism and the amount of prism is increased until blur/break/recovery. Repetition can improve the fusional amplitude

6. Near to Far Jumps

Exercises accommodation and vergence together. Must maintain clear single vision.

Facility Training - Prism Flippers

These consist of two pairs of prisms mounted on a horizontal bar with base in prism on top of the bar and base out on the bottom. The idea is to flip between them when the patient is viewing at a certain distance.

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