Hmm, yes, I see. In this case, the only solution that comes to my mind is to disable the light "Affect Specular" parameter. With this parameter disabled and the shape opacity set to 0.0, the lights should be invisible for the refracted rays, but the problem is that this light is not going to affect the specularity of any scene surface, so not sure if this could help.
And the other solution that you could try is to disable the light for glass objects using the Light Pass Mask feature (that you can find the LWOctane custom object properties plugin). You could group all the lights inside a pass and disable them for the glass objects.
Hope it helps,
Computer Graphics Software Developer
Octane plugin development and support: LightWave and Houdini