A female presents with loss of eyesight in both eyes, right more than left. all tests-are normal fundus normal. On closing eyes patient can touch both tips of her fingers, with left eye closed but not right. diagnosis fund (AIIMS Nov 2011)
|B||Anterior ischemic optic neuropathy|
|C||Functional visual loss|
(Ref: parson's 19th edition pg 150-52)
1. Pupil lary reaction is affected in optic neuritis and AION.
2. Also both of these will have other features like painfull eye movts in optic neuritis.
3. NAION – h/o DM or HTN
4. MV retinitis No sudden bilateral loss of vision.
5. Optic neuritis is typically unilateral.
1. Functional Visual Loss is a decrease in visual acuity and/or visual field not caused by any organic lesion. It is therefore also called non-organic visual loss (NOVL).
1. The decrease in visual acuity may involve one or both eyes and may vary from mild blurriness to complete blindness.
2. Visual field defects They may include constricted or tunnel visual fields, hemianopias, etc.
1. Functional visual loss (FVL) is commonly associated with concurrent diagnoses of depression, anxiety, panic attacks, and fibromyalgia.
a. Tunnelling of vision or tangent screen.
b. Spiralling, Crossing, or Stacking of isopters on Goldmann visual field.
c. Cloverleaf pattern on automated visual field.
1. Visual Acuity (VA):
The standard OKN drum induces optokinetic nystagmus and corresponds to 20/400 vision.