Performing a standard eye examination in neurology
EyeSeeCam is a wearable head-mounted device allowing objective measurement of eye movements. Eye movement disorders, even if subtle, can be detected, which helps improve the sensitivity and specificity of the clinical diagnosis. Supranuclear vertical saccade palsy, which can develop into complete gaze palsy in the course of the disease, is an eye movement disorder that can be detected in more than 95% of all patients with Niemann-Pick type C (NP-C). By careful examination it can often be recognized before other neurological symptoms become apparent. Even though detectable by performing a bedside examination of eye movement, in clinical practice supranuclear saccade palsy is often missed in the differential diagnosis of NP-C, especially in the early course of the disease and younger patient populations with NP-C.
A study validating EyeSeeCam for detection of progressive supranuclear palsy (PSP) showed that the gaze-driven video camera setup allowed detection of impaired saccade velocity and amplitude (Marx et al. 2012). The method is also useful to evaluate disease progression through repeated examinations.
Using EyeSeeCam to examine NP-C patients revealed that these patients not only show macroscopically detectable slow saccades but also different saccade patterns including staircase and pursuit-like movements when eliciting vertical saccades. In addition, horizontal saccades are also slower than in healthy volunteers (Bremova et al., unpublished).
In contrast to other methods such as scleral search-coil technique, EyeSeeCam is a non-invasive, mobile device, which includes a battery of vestibular and ocular motor tests. This makes it a useful tool for detection of eye movement disorders, especially for disorders such as slowing of saccades, which can be difficult to detect using bedside examinations alone.