Transcript Reliability of Aberrometry in Prescribing Glasses for the Undilated

Reliability of Aberrometry Versus Cycloplegic Retinoscopy in
Prescribing Glasses to Undilated Child
S.A. Erzurum, MD FACS
Aylin Sarac
Financial Interest

The authors have no financial interests in
any of the topics discussed in this study.
Purpose of Study

Retinoscopy is a difficult skill for many eye care
professionals.

Children are a difficult subpopulation for eye care
professional to refract.

Inaccurate glass prescribing occurs for many children.

Dilation necessary for accurate refraction but disliked by
children and family.
Purpose of Study



Find a reliable method for non-specialized eye
care providers to prescribe glasses for children.
Reliable method should be easy and quick.
Find method that eliminates/reduces need for
dilating drops to check refraction.
Method

iZON Aberrometer was machine used for comparison to
cycloplegic refraction.

Images are taken before dilation.

Child sits upon parent’s lap and multiple rapid images are
obtained.

Immediately upon taking image, analysis is provided of
sphere, cylinder, axis, level of aberrations, and quality of
image.

Example of reliable image
capture.

Prescription measured and
reported as sphere, cylinder,
and axis.

Aberrations measured and
reported in green, yellow or
red.

Pictures demonstrate how
patient sees at night.

Example of poor
image and unreliable
readings.

No measurements are
provided for aberrations.

Whatever prescription was
captured is reported, but
may not be reliable.

Example of right eye with poor
image capture and left eye with
excellent capture.

Right eye results for refraction
may not be reliable.

Left eye results reliable.
Method

Prospective consecutive series of 256 eyes in 128
pediatric patients involved in full exam.

Age range of 3 to 18 years.

iZON aberrometer images prior to dilation.

Full eye exam with cycloplegic refraction.

No patients were excluded, and all were examined by the
same pediatric ophthalmologist.
Results

CYCLOPLEGIC
(mean +/- SD)
Sphere
0.42 + 2.95
Astigmatism 0.74 + 0.91
Spheric equiv 0.75 + 2.91
ABERROMETER
(mean +/- SD)
-0.05 + 2.16
0.92 + 1.52
0.39 + 2.17
Age (mean + SD) 8.1 + 3.2 years; Mode 7 years
Range 3-18 years
Female
Male
62
66
48.4%
51.6%
Prevalence of Eye Disorders in Study Patients

Prevalence of Eye Disorders
–
–
–
–
–
–
–
–
–
–
–
Normal
Esotropia
Amblyopia
Exotropia
Cerebral palsy/
developmental delay
Congenital nystagmus
Cataracts
IDDM
Duane’s
Best’s
Coloboma
120
32
29
9
7
4
3
4
3
1
1
46.9
11.3
12.5
3.5
2.7
1.6
1.2
1.6
1.2
0.4
0.4
Reliability of Aberrometer

Only 45 eyes of 256 (17%)had an unreliable reading and
were excluded from comparison.

26 eyes of these 45 (64%)had ocular pathology which
would have directed them to sub-specialized care.

Immediately upon taking image, examiner is aware of
reliability of image.
Results of Comparison between two Methods

Comparison between aberrometer and cycloplegic results
were made in each area of sphere, cylinder, and axis.

In all categories, correlation was high between the two
methods.

Offset and slope of the best fit regression were calculated
for each.

All comparisons showed the slope was very close to 1.
Y cyclo sphere = 1.04 X izon sphere + 0.469
Model ANOVA F = 1552.93, p < 0.001
R = 0.934
Y cyclo SPHEQ = 1.019 X izon SPHEQ + 0.400
Model ANOVA F = 718.782 p < 0.001
R = 0.865
Y cyclo astig = 0.909 X izon astig – 0.026
Model ANOVA F = 766.735 p < 0.001
R = 0.887
Sphere
Astigmatism
Spherical
Equivalent
Conclusions

iZON aberrometer is a reliable method of refraction to
assist practitioners uncomfortable with cycloplegic
refraction in children.

iZON aberrometer gives a reliable reading and a high
correlation with cycloplegic refraction.

Group of patients who showed higher unreliability by
aberrometry measurements had a higher chance of
ocular pathology.