<prompt> Which clinical feature of differentiates orbital apex syndrome OAS from superior orbital fissure syndrome SOFS?ProptosisHorners syndromeLoss of visionLoss of ocular movements  <response>: Proptosis and loss of ocular movements can occur in both. Horner syndrome is more likely a feature of cavernous sinus syndrome which differentiates it from superior orbital fissure syndrome. As orbital apex syndrome affects optic canal , it causes loss of vision which differentiates it from SOFS. 