Sudden Painless Loss Of Vision: Differential Diagnosis

Causes:
1.Retinal Detachment
2.Retinal Artery Occlusion
3.Retinal Vein Occlusion
4.Amaurosis fugax
5.Ischemic Optic Neuritis
6.Cataract Due To Traumatic or Metabolic Cause
7.Lesion involving the neuronal visual pathways: optic tract, chiasm, Lateral geniculate nucleus, cortex

Differential Diagnoses:

1.Retinal detachment

Risk factors: high myopia, glaucoma, family history, previous surgery, and trauma
Symptoms: flashing lights (photopsia), floaters, and shadow across visual field
Signs on Exam: APD, retinal folds
Treatment: pneumatic retinopexy, scleral buckle, pars plana vitrectomy

2.Retinal Artery occlusion

Symptoms: sudden loss of vision in the visual field that corresponds to the territory of the obstructed artery

Branch retinal artery occlusion:
90 % are due to emboli, cardiac or carotid in origin.
Exam: ischemic whitening of the retina in the territory of the obstructed artery, retinal arteries distal to the blockage are attenuated, might see embolic material

Central retinal artery occlusion
In central retinal artery obstruction, the blockage is within the optic nerve itself and the site of obstruction could not visualized. It is believed however that most cases are due to thrombus formation. It could also be due to extrinsic nerve compression due to orbital or optic nerve tumors, inflammation or trauma.
Exam: cherry red spot in the macular area
Management: There is no proven treatment for retinal artery occlusion. If caught within 72 hours trials of dislodging the emboli (by massaging, paracentesis, and lowering the intraocular pressure), or thrombus dissolution, or increasing oxygenation to the retina, have been tried.

3.Retinal vein occlusion

Risk factors: hypertension, diabetes mellitus, and hyperviscosity syndromes
Symptoms: rapid unilateral painless loss of vision
Exam: dilated tortuous veins, cotton wool spots, and retinal hemorrhages
Management: panretinal photocoagulation for neovascularization

4.Amaurosis fugax

Unilateral tansient visual loss
Cholesterol and/or fibrin platelet emboli
Exam: may be normal, may show Hollen-Horst plaques
Management: evaluate for cardiac or carotid disease. Aspirin therapy

5.Arteritic Ischemic optic neuropathy

Weight loss, anorexia, fever, jaw claudications, headache, scalp tenderness, proximal joint and muscle pain
Exam: altitudinal visual field defects, pale swollen optic nerve
High ESR
Management: start high dose steroids therapy, schedule for a temporal artery biopsy within a few days (pathology results are the same up till 1 week after treatment)

6.Cataract

Acute metabolic changes or trauma can cause a cataract

7.Neurologic disease

Lesion involving the neuronal visual pathways: optic tract, chiasm, Lateral geniculate nucleus, cortex
Symptoms: painless decrease in the visual field
Exam: ophthalmologic exam is usually normal, might find some associated neurologic findings
Management: LP, CT, MRI and manage accordingly