Final answer:
The likely diagnosis for the patient is Pseudotumor cerebri, indicated by symptoms of increased intracranial pressure, normal imaging results, and elevated lumbar puncture opening pressure.
Step-by-step explanation:
The most likely diagnosis for the 19-year-old female presenting with visual blurring, headaches worsening in the morning, and bilateral papilledema on fundoscopic examination, is Pseudotumor cerebri (also known as Idiopathic Intracranial Hypertension).
This condition is characterized by increased intracranial pressure without any detectable intracranial pathology on imaging studies such as CT or MRI, as seen in this patient. The elevated opening pressure on lumbar puncture without abnormalities in cell counts, protein, or glucose further supports this diagnosis. Pseudotumor cerebri commonly affects young, obese females and can be exacerbated by the use of oral contraceptives.