THUR 231 Developing a new rating scale for ocular myasthenia gravis

Ocular Myasthenia Gravis (OMG) causes ptosis and diplopia, which can be disabling. For this study, OMG is defined as MG patients who have ocular symptoms only and no generalised involvement. A robust way of assessing the severity of OMG symptoms is important for research, to assess treatment and outcome. The rating scales recommended for MG research have a predominant focus on generalised disease, and are insufficiently sensitive for OMG due to the limited number of ocular questions. This study aims to create a new rating scale for OMG that is sensitive, reliable and clinically usable. We present our proposal of such a rating scale, which incorporates physician- and patient-rated components. We report the preliminary results of this pilot observational cohort study, in 60 patients with OMG. We compare the results of this with the MG composite scale. Future work is planned to validate this rating scale and to develop this alongside the MG Impairment Index (MGII). For future phases of this study we plan to assess the usability of this rating scale by Neurologists without specialist Neuro-ophthalmology. We invite feedback from Neurologists at the ABN.