I know that a lot of MD schools have been doing that during this admissions cycle. I was also told by an OD admissions counselor that this admissions cycle is extremely slow. So being on hold probably means that they are waiting to view other applications that are just trickling in before they fill the class. I would focus on updating ur application periodically. Meaning, maybe sending another lor or quickly updating ur grades or add any other extracurriculars. Schools def do like being updated and in your case should def help. Maybe you can land a chem tutoring job or worse case scenario retake chem or take an upper level chem. Also, send a letter of intent if its your first choice. On the brightside, its only 2 more months till january and I find it hard to believe their applicant pool is going to increase that drastically, especially over the holidays.
It is my first choice, but letter of intent, really? Never heard of someone doing that, but I guess I wouldn't write it off. I've heard of Med schools doing this all the time too, but never optometry schools, but IU does have the latest interview season I think. On the other hand what's the point of applying early if not for rolling admissions!!!???!!