Aniseikonia in relation to strabismus, anisometropia and amblyopia.
OBJECTIVE
To study the interrelationships among these four entities which are critical to binocular vision and its precision.


METHODS
102 selected patients (for their ability to have stereoscopic depth perception, a requisite for space eikonometry) were evaluated. Patient testing included stereoscopic testing, Essilor Projection Space Eikonometry, ultrasonic echographic axial length measurements and orthoptic evaluation. Aniseikonia was measured on the Essilor Projection Space Eikonometer.


RESULTS
1. Anisometropia alone was correlated with a marked increase in amblyopia, a moderate increase in aniseikonia and no noteworthy increase in strabismus. Statistical analysis (chi square ratio) showed that persons with elevated anisometropic values had a 4.4 fold increased risk of aniseikonia (p=.003). 2. Aniseikonia alone was not responsible for marked variations in strabismus. 3. Amblyopia was correlated with increases in anisometropia and aniseikonia. 4. Adding aniseikonia to anisometropia produced a possible increase in strabismus and a great increase in amblyopia (using Fisher's Exact Test, 2-tailed). 5. Spearman correlations of the "absolute values" (the mean of the mathematical difference between the two eyes of anisometropia and amblyopia) were as follows: anisometropia (abs) vs. aniseikonia r=.294, p=.006; anisometropia (abs) vs. amblyopia (abs) 4=.555, p=<.001; amblyopia (abs) vs. aniseikonia r=.234, p=.02.


CONCLUSIONS
Aniseikonia per se does not appear to have a major causal role in amblyopia or strabismus, but anisometropia does for amblyopia. This role is greatly augmented by aniseikonia and this combination may then produce strabismus.
Lubkin
V
V
The Aborn Eye Research Center, The New York Eye and Ear Infirmary, New York, New York 10003, USA.
Kramer
P
P
Meininger
D
D
Shippman
S
S
Bennett
G
G
Visintainer
P
P
D000550:Amblyopia / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D000839:Aniseikonia / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D015858:Anisometropia / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D003867:Depth Perception; D003941:Diagnostic Techniques, Ophthalmological; D018450:Disease Progression; D006801:Humans; D013285:Strabismus / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D014787:Vision Tests / Q000379:methods; D015348:Vision, Binocular