1. very informative lectures. Generally how many times a patient generally have to change the prism prescriptions before being stable?[ It is important to counsel patients regarding the costs of prisms]
    i) For isolated 6th nerve palsy
    ii) For isolated 3rd nerve palsy. (do you incorporate lid crutches as well?)
    is it better to give trial of prism after 6 months of these palsies?

    Thank you.

    1. 1. If I think I need to change out the prism then I always do Fresnel to limit the cost for the patient. I typically bring them back in 4-6 week intervals. If they notice a difference sooner than that then I have them call me and bring them back in sooner. The amount of times is quiet variable – it could be one or five (usually only 1-3 times on average I’d say)

      2. I don’t typically use an eyelid crutch because then they can’t typically blink at all unless they have a great Bell’s reflex and then they just get severe dryness. It also typically helps resolve their diplopia temporarily until the lid comes up. If it does not, then I refer for ptosis surgery first and then we deal with the diplopia (whether it be with prism or surgery or occlusion (I have used CL’s here with success due to photophobia from the larger pupil)

  2. very informative lecture. thank you.
    question : can we give horizontal prism to one eye & vertical prism to other eye to overcome vertical+horizontal diplopia. eg. 2^ BD on OD & 6^BI OS.
    please send me the app you told about record keeping. thank you.

    1. Yes you can do this. You can also combine in the same lens. In your example provided, I would typically write this out as:

      OD: 1 BD and 3 BI
      OS: 1 BU and 3 BI

      This way the lenses will look symmetric.

      The app is called 9 Gaze.

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