<prompt> All of the following are the features of Horners syndrome Except:Ptosis and Miosis in ipsilateral eyeAnhydrosis of ipsilateral faceHetrochromia iridesApparent exophthalmos  <response>: Ans. is d i.e. Apparent exophthalmos Horners syndrome consists of classical triad of ipsilateralPtosisMiosis Anhidrosis loss of sweatingOther signs of the Horners syndromeSlight elevation of the inferior eyelidThe pupillary reactions are normal to both light and accomodation.The pupil is slow to dilateHeterochromia ipsilateral iris is of lighter color is seen in congenital Horners syndromeNote that the anhidrosis is present only if the lesion is below the superior cervical ganglion.Causes of Horners syndromeHorners syndrome is caused by a lesion of the sympathetic pathway eitherin its central portion which extends from the posterior hypothalamus through the brainstem to the upper spinal cord.in its preganglionic portion which exits the spinal cord and synapses in the superior cervical stellate ganglionin its postganglionic portion which extends from the superior cervical ganglion to the orbit via the carotid plexus and the ophthalmic division of the trigeminal nerveSympathetic fibres supply the Superior tarsal muscle and the iris dilator muscle. Paresis of the Superior tarsal muscle causes ptosis and that of iris dilator leads to miosis. Some books write that its the paresis of Mullers muscle that causes ptosis but According to Grays Anatomy its the Superior tarsal muscle whose paresis causes ptosisMelanocyte maturation in the iris of a neonate depends upon sympathetic innervation, thus lack of sympathetic innervation in congenital Horners syndrome interferes with melanin pigmentation of the iris leading to iris of lighter color HeterochromiaNote that the Ptosis in Horners syndrome is mild to moderate and not complete due to preservation of Levator palpebrae superioris muscle function.Horners syndrome and Enophthalmos Kanski, Yanoff ophthalmology and Vaughans ophthalmology a Lange publication do not include enophthalmos in Homers syndrome.Articles at above mentioned web addresses clearly write that- though enophthalmos has traditionally been included in Horners syndrome it is only an illusion of enophthalmos caused by the ptosis.Actual measurement with exophthalmometry clearly demonstrates the lack of enophthalmos. The enophthalmos is only apparent. The small palpebral fissure makes the eye look sunken in on the affected side, but the position of the globe in the orbit remains virtually unchanged. 