Differential Diagnosis for Prolonged Flashing Sensation

Given the scenario where nothing has been found and the flashing sensation has been ongoing for over 2 years, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis
  • Benign Phosphenes: This condition is characterized by seeing flashes of light, especially in low light conditions, and is often associated with aging or previous eye surgeries. The prolonged duration without other symptoms makes this a plausible explanation.
• Other Likely Diagnoses
  • Migraine Aura: Some individuals experience visual auras, including flashing lights, as part of their migraine episodes. The absence of headache does not rule out migraine aura, as some people experience acephalgic migraines.
  • Ocular Migraine: Similar to migraine aura, ocular migraines can cause flashing lights without the headache, often resolving on their own.
  • Vitreous Detachment: As people age, the vitreous gel in the eye can shrink and pull away from the retina, causing flashes of light. This condition is usually benign but can increase the risk of retinal detachment.
• Do Not Miss Diagnoses
  • Retinal Detachment: Although less likely if nothing has been found, retinal detachment is a medical emergency that can cause permanent vision loss if not promptly treated. Flashes of light can be a symptom, especially if associated with floaters or a curtain descending over the visual field.
  • Posterior Vitreous Detachment with Retinal Tear: Similar to vitreous detachment, but with a tear in the retina, which significantly increases the risk of retinal detachment.
• Rare Diagnoses
  • Choroidal Melanoma: A rare type of eye cancer that can cause visual disturbances, including flashes of light, though it's less commonly associated with this symptom alone.
  • Optic Neuritis: Inflammation of the optic nerve, which can cause flashing lights among other symptoms like pain and vision loss, often associated with multiple sclerosis or other demyelinating diseases.

Each of these diagnoses has a brief justification based on the symptoms described and the importance of not missing critical conditions that could lead to severe outcomes. The single most likely diagnosis and other likely diagnoses are based on common conditions that match the symptom profile, while the "do not miss" category highlights conditions that are critical to diagnose due to their potential for severe consequences, even if they are less likely. Rare diagnoses, though less probable, are included for completeness and to ensure that all potential avenues are considered.