Honer's syndrome includes upper eyelid ptosis, constricted pupil on the same side as the ptosis, and deceased sweating in the immediately adjacent skin. Having just a ptosis does not make a Horner's syndrome. If you have an actual Horner's syndrome, you need to be evaluated for why you have Horner's syndrome. The list of potential causes is long and varied from minor head trauma (repetitively heading a soccer ball to chest wall tumors. If your pupil is normal, then you just have upper eyelid ptosis. For a pure Horner's syndrome related ptosis, a Mueller's muscle conjunctival resection ptosis surgery can be a very appropriate surgery. In your case, I can almost guarantee that a Muellerectomy will be the wrong surgery for you. You photo suggests that you have almost 3 mm of upper eyelid ptosis. The Muellerectomy is only good for 1-2 mm of upper eyelid ptosis. Your upper eyelid very much has a configuration of a central leavtor disinsertion with retraction of the anterior orbital fat into the orbit. These are best addressed with an anterior levator resection ptosis repair irrespective of your response to the neosynephrine drop test.It can be helpful to get more than one option before having surgery. The American Society for Ophthalmic Plastic and Reconstructive Surgery maintains a regional directory on their website that can help you find a highly qualified surgeon close to home.