Hi KatyMac,
DandyDan here - whose daughter had conversion disorder causing sight loss for a long period of time.
I haven't been around for a while but wanted to see how things were going for your daughter. If it appears that the diagnosis was conversion disorder, it is at least clear that that is the route to follow. Once we had our diagnosis, there was little else to do but persist with the psychologist, and it worked over 13 months of weekly appointments. We had the scans, the neurology and specialist opthalmology appointments, the lumbar punctures to test for pressure on the optic nerve, but in the end all this was not the reason and caused extra stress.
We were told in no uncertain terms not to treat our daughter as 'blind' or treat her as if she was visually impaired (other than guiding her subtly when walking). We were able with the support of SEN staff at the school to make sure the school understood my daughter's situation as a "temporary" situation, to support her with printed-out lessons, or an assistant or allowing me to come into school with her for lessons. They also arranged a CAF - Common Assessment Framework in order to continually assess her additional needs, drawing together a multi-disciplinary team of people involved in her case.
Two years down the line she has had only two very brief sight-losses (an evening+early morning period, and a two-hour morning 'blip') in the last 12 months and both caused by sudden intense stress. And today she finished her GCSE exams with no problems whatsoever with her sight, so we are really celebrating that as well. The only concession was that the school still thought it important to let her take her exams in a separate small room to lessen the stress for her. Our school has been superb in this, and in allowing me to go in and do lessons with her when she wasn't able to see.
Another thing to remember is what someone posted above - that huge numbers of teen girls experience heavy levels of stress and the body and mind cope with it in different ways. Looking up 'conversion disorder' on the internet brings you articles that suggest a specific trauma is the cause - and that can surely be true, but not in all cases. Inner conflict and tension can just make the brain put a halt to things and switch off the visual signal.
If your consultant is helping you to get an MRI scan, then that is good, but increasing numbers of exploratory appointments can bring their own stress, and also add to the number of days missed from school.