9.1 Background

Neuro-ophthalmologists devote much of their time to the eye manifestations of neurological disorders, including stroke, migraine, multiple sclerosis, cerebral tumours and head injury. Intensive investigations into the aetiology and pathogenesis of these disorders continues and this will inevitably impact on the prevalence of untreatable neural blindness.

In addition to this research activity three areas of direct relevance to ophthalmic research can be identified for neuro-ophthalmology. In each of these areas preliminary achievements over the past twenty years can be further developed over the next five years, at least at a basic science level, pointing a way to clinical trials in the future.

  9.2 Research Potential

  9.2.1 Neuro-transmission, apoptosis and neuro-protection

Pharmacological treatment to sustain the vitality of retinal ganglion cells following focal ischaemic or toxic injury.

  9.2.2 Neural regeneration

Neurons in the visual pathways have yet to be re-generated but preliminary studies have now reported successful regeneration of optic nerve axons in mammals and also the re-establishment of synaptic connections between these axons and cells in the brain proper. The capacity to re-establish appropriate rather than random connections after ganglion cell regeneration remains a crucial issue in the achievement of a meaningful return of visual function.

  9.2.3 Electronics and bionics

The concept of a bionic eye or electronic visual prosthesis has long been a part of popular culture. Efforts continue focusing primarily on individuals with no residual vision following loss of function.

  9.2.4 Gene therapy

Patients with hereditary familial optic neuropathy and in particular young adults with Leber's hereditary optic neuropathy represent a high priority for the application of these therapies. After the loss of one eye, the same clinical event in the fellow eye is virtually inevitable and this offers a highly suitable targeted group for the application of gene therapy techniques.

  9.2.5 Clinical research in neuro-ophthalmology

There remains an urgent need to refine and make more systematic the wide-range of clinical psychophysical and electrophysiological tests currently available to assess afferent visual function. Perimetry remains the most reliable clinical means of localising lesions in the visual pathways. Unfortunately the sophisticated techniques in use remain subjective and time-consuming and not tolerated by a significant portion of patients. Efforts to develop accurate rapid objective mapping and quantification of sensitivities throughout the field of vision continue, most likely through the modification of the visual evoked response test. These results could be correlated with psychophysical and pupil perimetry abnormalities to further refine and rationalise the present array of tests in use.

In contrast to subjective psychophysical techniques, confocal scanning laser ophthalmoscopy, optical coherence tomography and retinal thickness analysis are all evolving objective techniques, which are likely to prove to be of direct relevance to the assessment and treatment of patients with acquired optic neuropathies.

   9.3 Research Priorities

  9.3.1 Epidemiological and Service Issues

· Visual rehabilitation in untreatable neural blindness.

  9.3.2 Clinical and Laboratory Issues

· Protection of vision in chronic raised intracranial pressure syndromes.
· Rehabilitation of binocular function in neurogenic squint.
· Immunotherapies for inflammatory optic neuropathies.