Advanced Binocular Refraction Seminar

Just a quick summary for those who couldn't make the conference hosted by Carl Zeiss Vision and Supervisionaries. Its been a fantastic two days and I think my brain will take some time to recover from the information overload. The seminar was on the MKH (correction of heterophoria according to the methodology of J-Haase) technique used widely on the continent but very rarely here....continued after the break

The basis of the system is to look at fixation disparity as a fluid process which goes through many stages, rather than just "a slip on the mallet unit". It was presented by Georg Stollenwork who is President of the IVBV (International Association of Binocular Correction) and also a guest lecture by Alex Levit, one of the only practitioners in the UK to use the technique in regular practice.

The technique consists of eight polarised plates:

 The first, the cross test, is designed to only correct the motor element of the phoria. The next two, the pointer tests are designed to correct the initial error when the oculocentric direction centres have not moved. The rectangle is for anisokonia and vertical misalignments. These are all comparable to other tests.

The next four are unique to the MKH system are designed for indepth analysis of stereoscopic sensitivity, speed of recognition and depth of stereopsis.

The seminar was clearly aimed as an introductory session to the system providing as much knowledge as possible in terms of the practicle aspects. Unfortunately while the research base was alluded too there was no further reading list available and a lot of the research mentioned was only in the German language.

The plates are in a suprising number of charts already including the Zeiss iPolatest, BiB PolaVistaVision and the new Thomson Test Chart 2000 Xpert3D. It is very important that the sizing of the targets is correct and that the polarisation is perfect so no ghosting is seen. There is a near vision unit to match, available from Zeiss, but unfortunately it's not digital....yet!

Its a fascinating methodology and one that could well come more into play in the UK as more demand is placed on accurate binocular vision correction, especially given the onward march of 3D technology.

 Does your digital polarised test chart have these on?

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