Metamorpsia is a deviation of vertical and/or horizontal straight lines, detected by looking at a standard grid (such as the Modified Amsler chart).
The patient may notice a visual instability due to eye movements made to better focus on an object.
Micropsia: objects appear smaller than they really are
Macropsia: objects appear larger than they really are
Conditions associated with metamorphopsia iinclude:
(1) age-related macular degeneration
(2) diabetic macular edema
(3) nondiabetic macular edema
(4) vitreoretinal interface disorder
(5) retinal detachment
(6) central serous chorioretinopathy
(7) macular serous elevation
The onset of macropsia may precede changes that can be detected on an exam of the fundus.
