Pooja B. Jamnadas, MD, Peter Russo, OD, William Bonk, Shuchi Patel, MDLoyola University Chicago, Stritch School of Medicine, Department of Ophthalmology, Maywood IL

At our institution

INTRODUCTION

RESULTS

CONCLUSIONS

• IRB approved, prospective case control study

• 9 patients presented to the Loyola eye clinic for routine examination

• Patients were provided appropriate informed consent and were aware of the risks and benefits of participation

• Patients underwent Spectralis OCT (Heidelberg Engineering USA) testing with and without their daily contact lenses in place

• We studied refractive error, RNFL, Q value with and without contact lenses in place

• Subgroup analysis was conducted with chi square analysis analyzing whether degree of refractive error impacted pertinent variables

• Patients with astigmatism were included using spherical equivalence

• Subgroup analysis was also performed on whether rigid gas permeable or soft contact lenses had an impact on pertinent variables

METHODS

Retinal nerve fiber layer (RNFL) measurements are often used to aid

ophthalmologists in the diagnosis and management of glaucoma. One

of the challenges in measuring retinal nerve fiber layer thickness is

obtaining good quality scans with accurate measurements. Our study

serves to report the effects of contact lenses wear on RNFL

measurements. Furthermore, we sought to determine if the degree of

refractive error impacts RNFL measurements or Q values with contact

lens wear. We studied patients with both soft and rigid gas permeable

lenses.

• At lower refractive errors, better quality studies are obtained without contact lenses in place

• Higher refractive errors which are corrected with contact lenses may lead to improved quality

• Distortion due to the contact lenses may be negated when refractive error exceeds -5.00 diopters

• Further studies are needed with larger cohorts in order to create an appropriately powered trial

which can provide conclusive information

ACKNOWLEDGEMENTS:

This work was supported by The Richard A. Perritt Charitable Foundation.

Purpose: The purpose of this study is to determine if statistically

significant differences exist between retinal nerve fiber

layer (RNFL) measurements and quality (measured in Q

value) of optical coherence tomography (OCT) in

patients with and without contact lenses. We also

aimed to determine if higher refractive errors made a

larger effect on the RNFL and Q value measurements.

We examined soft and rigid gas permeable lenses.

Methods: After obtaining IRB approval and consent, patients in

the Loyola eye clinic had their RNFL measured with and

without contact lenses using the Spectralis OCT

(Heidelberg Engineering USA). The patient's refractive

error, RNFL, and Q value were recorded. A paired t test

was used comparing the average RNFL and Q value with

and without contact lenses. A subgroup analysis was

done looking at patients with refractive errors lower

than -5.0 diopters, and equal to or above -5.0 diopters.

For patients with astigmatism, the spherical

equivalence was used. Subgroup analysis was also

done comparing RGP lenses and soft contact lenses.

Results: No statistically significant difference is present in RNFL

measurments and OCT quality with or without contact

lens wear overall. Subgroup analysis found no

statistically significant difference in RNFL. The

difference in Q value was not significant in subjects with

higher refractive errors. Patients with a lower refractive

error with soft contact lenses had significantly better

quality studies without contact lenses. Patients with

RGP lenses had significantly better quality studies

without contact lenses. Gross examination of the study

images does show more clear images in patients with

higher refractive errors when contacts are in. Although

not significant, average Q values are higher in patients

with contact lenses with refractive errors above -5.00.

Conclusions:We conclude that at lower refractive errors, better

quality studies are obtained without contact lenses.

However, we hypothesize that with higher refractive

errors, correcting refractive error with contact lenses

provides an improved quality which begins to negate

the distortion caused by the contact lens itself.

Therefore, additional studies that include more patients

with higher refractive errors are needed to see if a

larger n will allow for results to reach statistical

significance.

Financial Disclosures: None

ABSTRACT RESULTS

A PROSPECTIVE STUDY EXAMINING CONTACT LENS WEAR, REFRACTIVE ERROR, AND OPTICAL COHERENCE TOMOGRAPHY RETINAL

NERVE FIBER LAYER MEASUREMENTS

• Patients with a lower refractive error

had significantly better quality

studies without contact lenses.

• Patients with rigid gas permeable

lenses had better quality studies

without contact lenses.

• Although not significant, average Q

values are higher in patients with

contact lenses with refractive errors

above -5.00.

Overall

RGP SCL SCL <-

5.00

SCL ≥-

5.00

0

5

10

15

20

25

30

35

26.5 26.2

31.7533

25.1 24.7

22.9

28.427.4

21.6

Mean Q value

 Mean difference in NFL measurement p value

All eyes (RGP +SCL) 2.5 0.1654

RGP lenses (-3.50 to -6.50) 0.75 0.6378

SCL overall 3 0.1586 SCL with refractive error <

- 5.00 1.29 0.103

SCL with refractive error ≥ -5.00 5.2 0.1082

  RGP lenses (-3.50 to -6.50) SCL <-5.00 SCL ≥-5.00 Total

Number of patients 2 4* 4* 9

Number of Eyes 4 7 7 18

Males 1 1 2 3

Females 1 3 2 6

Average Age 33 29 34 32

*one patient's refractive error was >-5 in one eye <-5 in the other

WITH CONTACTS

WITHOUT CONTACTS

p=0.99 p=0.01 p=0.00

2

p=0.87 p=0.18

Gross examination shows better image quality

with contact lenses

Contact Lenses No Contact Lenses