BIOMETRY OF THE DOMINANT EYE

– variations in eye ball diameters and eye dominance of healthy adults.

Alicja Semanicka1, Magdalena Grajek2 1 Laboratory of Vision and Optometry Physics, Adam Mickiewicz University, Poznan, Poland

2 Quantum Electronic Division Faculty of Physics Adam Mickiewicz University Poznan, Poland

Motivation: Eye dominance has primary role in binocular functionality. Despite there is many researches about psychophysical aspect of eye dominance, we found insufficiency of investigation which examine eye dominance in biometric aspect. In our work we concentrate on myopic patients, with the same refractive error in both eyes and with anisometropia. We supposed that eye dominance might be connected with refractive error and biometric differences in dominant and non-dominant eye.

Purpose: To investigate the relation between eyesight dominance and biometric

Participants:

differences in dominant and non-dominant eye in myopic patients

To present new in vivo ultrasonography methodology.

Free from eye surgery, amblyopia, strabismus and other Visual acuity for distance and near: 0,9 or better for each eye.

Healthy young adults, Age: 18-40 y

Methods: Eye dominance:

Eye dominance was tested with three methods: 1. The Miles test – a subjective test for distance 2. The convergence near-point test – an objective test for near 3. The Porta test – a subjective test for near

Results: That methodology is

free from pressure which could make operator’s hand.

Patients were content with lack of discomfort.

Ultrasonography probe does not touch eyelid it is isolated by proper gel.

References:

Conclusions:

Analyzed groups:

D=N n=21

Difference in Refractive Error between Dominant Eye and Non-dominant eye less than 0,75 Dptr in Spherical Equivalent

D>N n=13

For Dominant eye higher Refractive Error than for Non-dominant eye. Difference more than 0, 75 Dptr in Spherical Equivalent

D<N n=5

For Dominant eye lower Refractive Error than for Non-dominant eye. Difference more than 0, 75 Dptr in Spherical Equivalent

Total enrolled 39

Right eye dominance 24

Left eye dominance 15

Average Age 24,2

Spherical Equivalent of the right eye

-3,68 ± 1,94 D

Spherical Equivalent of the left eye

-3,64± 1,93 D

Intraocular pressure [mmHg]

B-scan of eyeball [mm]

B-scan anterior segment [mm]

B-scan posterior segment [mm]

A-scan of eyeball [mm]

D=

N

p= 0,6982

p= 0,2195

p= 0,8031

p= 0,3808

p= 0,3808

n=21 Right Dominant= 15 Left Dominant= 6

D=N

Right &

Left

Dominance

n=21

Subgroups

D=N

Right

Dominance

n=15

D=N

Left

dominance

n=6

Intraoccular

pressure

D>N D≈N

p=0,918

D>N

p=0,1505

B-scan of

eyeball

D>N D>N

p=0,135

D>N

B-scan

anterior

segment

D>N D>N

p=0,058

D>N

p=0,8101

B-scan

posterior

segment

D>N D≈N

p=0,932

D>N

p=0,6075

A- scan of

eyeball

D>N D>N

p=0,256

D≈N

p=0,946

D>

N

n= 13 Right Dominant= 7 Left Dominant= 6

D>N

Right & Left

Dominance

n=13

D<N

Right & Left

Dominance

n=5

Intraoccular

pressure

D>N D<N

B-scan of

eyeball

D>N D<N

B-scan

anterior

segment

D>N D>N

p=0,2789

B-scan

posterior

segment

D>N D<N

A- scan of

eyeball

D>N D<N

D<

N

n= 5 Right Dominant= 2 Left Dominant= 3

p= 0,4498

p= 0,1409

p= 0,1304

p= 0,6851

p= 0,2789

• The assumption of normality was tested with Shapiro-Wilk test.

• The difference between dominant and nondominant eye was tested with one-way ANOVA.

Max

Average

Min

Standard deviation

Standard deviation

Eye dominance correlate with axial length and intraoccular pressure.

34/39 cases had more myopic dominant eye. At 10/34 difference were higher than

0,75 Dptr in Spherical Equivalent.

More myopic eyes had higher intraoccular pressure.

In groups: Right Eye Dominant (24 subjects) and Left Eye Dominant (15 subjects), dominant eye had higher refractive error, longer axial length and longer anterior and posterior segments.

Difference in eye intraocular pressure between dominant and non-dominant eye can influence axial length.

The most significant result we found in anterior segment in Right Dominant group p=0,058

There is no correlation between eye and hand dominance.

[1] Ching-Yu Cheng,et al. Assosiation of Ocular Dominance and Anisometropic Myopia; Anisometropic Myopia; [2]N. Astbury, B. Ramamurthy How to avoid mistakes in biometry; Community Eye Health Jurnal, December 2006, Vol. 19, No.60 [3] http://en.wikipedia.org/wiki/Ocular_dominance [4] D. Lopes-Ferreira, et al. Ocular Dominance and Visual Function Testing; BioMed Research International, Vol. 2013, Article ID 238943 [5] T. Handa et al. Effects of Dominant and Nondominant Eyes in Binocular Rivalry; Optometry and Vision Science, American Academy of Optometry 2004, Vol. 81, No. 5.

Ultrasonography: A-Scan

B-scan anterior segment B-scan posterior segment

B-Scan

Optic nerve

p= 0,1304

p= 0,98

p= 0,3128

p= 0,8746

p= 0,1409