Ocular Movement Physiology

Details

Title

Ocular Movement Physiology

Type

Stage One

Module code

HPS231

Requirement

Compulsory

Module objective

By the end of this module the Clinical Scientist in HSST, with respect to the diagnosis and management of patients with abnormal eye movements, will be able to record, analyse, synthesise, evaluate and apply their knowledge, perform and adjust a range of technical procedures and clinical skills, and demonstrate the attitudes and behaviours necessary for the role of a Consultant Clinical Scientist.

Knowledge and understanding

By the end of this module the Clinical Scientist in HSST will analyse, synthesise, critically evaluate and apply their expert knowledge with respect to the design, application and interpretation of eye movement examinations in patients of all ages. This will include expert understanding of:

normal ocular movements and fixation control

• extra-ocular muscles and their cranial nerve innervation
• central control of eye movements
• voluntary and involuntary eye movements
• optokinetic nystagmus
• vestibular ocular reflex
• eye movements resulting from head movement
• saccades
• smooth pursuit holding moving image on fovea
• vergence eye movements and holding corresponding points on the retinae
• voluntary nystagmus, end point nystagmus

congenital and acquired disorders of eye movements

• symptomatology of abnormal eye movements
• head movements, abnormal head posture, spasmus nutans
• aetiology of abnormal eye movements
  • innervation
  • muscle anomalies
  • orbital anomalies
• predisposing factors, e.g. prematurity, strabismus, neurodegenerative conditions, inflammation
• neurological nystagmus
• congenital idiopathic motor nystagmus
• the nystagmus associated with ocular or oculocutaneous albinism
• the nystagmus associated with congenital/inherited retinal disorders
• upbeat nystagmus – drugs, cerebellum, medulla
• downbeat nystagmus – craniocervical junction
• associations with systemic conditions, e.g. saccadic initiation failure, ocular flutter, opsoclonus, inter-nuclear ophthalmoplegia, see-saw nystagmusorbital anomalies
• principles of eye movement recording and analysis.

Technical and clinical skills

By the end of this module the Clinical Scientist in HSST will be able to demonstrate a critical understanding of current research and its application to the performance and mastery of the following technical skills:

• perform appropriate electrophysiological investigations to assess and quantify abnormal eye movements in disorders such as albinism, congenital motor nystagmus, inherited retinal disorders, etc.;
• select appropriate test of choice with an awareness of the system parameters: spatial and temporal resolution and the possibility to record multiple degrees of freedom of the eye:
  • electro-oculography applied to eye movements;
  • infra-red reflection tracker;
  • scleral search coil;
  • video-oculography;
• perform eye movement recording and calibration;
• recognise sources of artefacts and take steps to remove them;
• analyse waveforms:
  • recognise the shape of the slow phase and variations in directions of gaze
  • calculate foveation from the main sequencerecognise the shape of the slow phase and variations in directions of gaze
  • modify, design and develop new tests, changing the method of measurement according to task, need and clinical condition.

By the end of this module the Clinical Scientist in HSST will be expected to critically reflect and apply in practice a range of clinical and communication skills to encourage and communicate effectively with young patients, relevant clinicians, patients and the public. and other healthcare professionals and will:

• take a comprehensive history expressing the visual complaint in reference to eye movements;
• interpret appropriate electrophysiological investigations to identify underlying causes of eye movement disorders such as albinism or congenital/inherited retinal disease;
• perform and analyse eye movement recording, integrating data with other OVS measurements and images;
• interpret these results;
• produce a clear and informative report with recommendations for further diagnostics and/or treatments;
• communicate with patients, carers and families the implications of findings;
• within the multidisciplinary team advise on the best course of management and treatment, e.g. refractive correction, prisms, biofeedback, contact lenses, drugs– baclofen, periodic alternating nystagmus (PAN) , surgery e.g. Anderson Kestenbaum procedure, artificial divergence, maximal horizontal recession, tenotomy;
• reflect on the challenges of applying research to practice in relation to these areas of practice and suggest improvements, building on a critique of available evidence;
• take a holistic approach in diagnosis and explaining possible consequences of unusual or abnormal eye movements to the child and family;
• strive to adapt current, and develop novel, tests to best describe and capture a patient’s visual impairment;
• reflect on the impact of eye movement disorders on everyday quality of life and strategies to minimise visual disturbance.