Episode 58 Polarization Glaucoma

Hi, I am Dr Thomas Whitelaw and in Episode 58, we're exploring a property of light that our visual system itself is remarkably poor at detecting, yet which can be extremely useful when incorporated into optical instruments: polarization. Polarization arises from the orientation of the electric field within a light wave. By selectively transmitting particular orientations of that field, optical filters can suppress unwanted reflections, separate images and reveal information about materials that alter the polarization state of light. In ophthalmology, these principles extend from relatively simple polarizing filters to sophisticated techniques such as scanning laser polarimetry, where the birefringence of retinal nerve fibres can be exploited to estimate the thickness of the retinal nerve fibre layer. Today's episode is divided into three sections: First: polarization filters in imaging. Second: clinical polarimetry. And third: applications in nerve fibre analysis.