Your degree of eyelid ptosis seems to vary between the photos. I would assume that a neuro-ophthalmologist would competently exclude myasthenia gravis but unless a tensilon test was done then it can't be excluded for sure. The blood tests are not 100% reliable. If your eyelid droop improves with an "ice test" then you likely have myasthenia, which is treated medically under most circumstances. The ice test is simple, put some wrapped ice over the area for a few minutes and see if your eye become more open (this would be a positive test). If you don't have myasthenia then, I would suggest an oculoplastic surgeon evaluation. We do these surgeries routinely with high success.
It sounds like you have the appropriate workup but a Tensilon test and even something as simple as an ice pack test on the eye should be performed as well. Typically an oculoplastic surgeon is going to be the best person for you to go to the there are a number of facial plastic surgeon to specialize in eyelid reconstruction as well. In your particular case when you go from a relatively normal lid position to a very ptotic lid position with fatigue or later in the day surgery can be a little trickier and that once it is repaired you may find that that eyelid is a little bit retracted or too high early in the day and then settles into a better position later on or as she become fatigued. Many patients find that this is just fine but he may want to discuss that particular postoperative phenomenon with your eyelid surgeon.
Chase Lay, MD
Double board-certified facial plastic surgeon
While it is true that a variety of specialist offer ptosis surgery, I would recommend focusing on fellowship trained oculoplastic surgeons. These are board certified ophthalmologist who are fellowship trained in eyelid plastic surgery. Not only are they extensively trained in eyelid plastic surgeon, they have the necessary equipment to examine the eye which will not be the case with the facial plastic or general plastic surgeon. The American Society for Ophthalmic Plastic and Reconstructive Surgery maintains a geographic directory on their website (ASOPRS dot org). As you have seen an neuroophthalmologist, you might ask them for a referral for an oculoplastic surgeon if they do not perform ptosis surgery themselves.
You do have ptosis and your doctor has done the work up. The next step is in person consultation. There are 3 group of surgeons that do this surgery including plastic surgeons, facial plastic surgeons and oculoplastic surgeons. The best is to find a surgeon that you feel comfortable with and has good before and after pictures.
There are multiple medical issues, including the Myasthenia gravis you mentioned that may cause this. If you have undergone a complete medical clearance for other issues, and this is a congenital ptosis, you should see an oculoplastic or facial plastic surgeon that is board certified and adept at complex eyelid repair.
You should be evaluated by an oculoplastic surgeon. If there is no medical cause of your left eyelid ptosis, surgery can be done to improve the condition.