Differential Diagnosis for Sudden Enlargement of Blind Spot in One Eye with High Myopia

• Single most likely diagnosis:

  • Retinal Detachment: This is the most likely diagnosis given the sudden onset of symptoms and the patient's high myopia. High myopia is a significant risk factor for retinal detachment, which can cause an enlargement of the blind spot due to the separation of the retina from the underlying tissue.

• Other Likely diagnoses:

  • Posterior Vitreous Detachment (PVD): PVD is common in highly myopic individuals and can cause symptoms similar to retinal detachment, including an increase in floaters and flashes of light, which might be perceived as an enlargement of the blind spot.
  • Macular Hole: Although less common, macular holes can occur in highly myopic eyes and may cause visual disturbances, including metamorphopsia and central blind spots.

• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):

  • Central Retinal Artery Occlusion: While less likely, this condition is an emergency that requires immediate attention. It can cause sudden, painless loss of vision, which might initially be perceived as an enlargement of the blind spot.
  • Optic Neuritis: This condition can cause a range of visual symptoms, including blind spots, and is important to diagnose due to its implications for underlying conditions such as multiple sclerosis.

• Rare diagnoses:

  • Choroidal Melanoma: Although rare, choroidal melanoma can cause visual disturbances, including an enlargement of the blind spot, especially if it grows large enough to affect the retina or optic nerve.
  • Pituitary Adenoma: While not directly related to myopia, a pituitary adenoma can cause bitemporal hemianopia, which might be perceived differently in each eye, potentially mimicking an enlarged blind spot in one eye if the tumor affects the optic chiasm asymmetrically.