The short wavelength electro-oculogram (SW-EOG) in best disease: preliminary results

Purpose; The clinical electrooculogram (EOG) is used for the diagnosis of bestrophinopathies to evaluate the function of the retinal pigment epithelium. The current ISCEV test protocol uses a broad band white light with luminance of 100 cd/m2. An alternative monochromatic 448 nm short wavelength (SW-EOG) has been proposed but to date has not been evaluated in clinical cases where the standard EOG is abnormal.

Methods; To evaluate the clinical potential of the SW-EOG four genetically confirmed cases of Best Vitelliform Macular Dystrophy were tested using the standard white (100 cd/m2) and SW-EOG (448 nm) at 30 cd/m2 to ascertain if the SW-EOG was also affected. In addition, a qualitative 5-point Likert survey was conducted to gauge overall patient comfort.

Results: In all four cases the SW-EOG was reduced and provided an equivalent clinical measure for RPE dysfunction. All four participants rated the SW-EOG as being more comfortable than the white standard EOG test.

Conclusions: This is the first demonstration of an alternative stimulus for the EOG that provided clinically valid results with greater comfort than the current ISCEV protocol. Further studies are required to validate the SW-EOG as an alternative to the white broad band stimulus.