Comparison of Tear Interleukin-6 level, Conjunctival Inflammation,

and Tear Film Function in Daily Conventional Hydrogel and

Extended Silicone Hydrogel Contact Lens Wear

Tri Rahayu

, Adisti

, Weni Puspitasari

and Umar Mardianto

Department of Ophthalmology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia

Recidency Training Program Student of Department of Ophthalmology, Faculry of Medicine, Universitas Indinesia,

Jakarta, Indonesia

Keywords: Soft Contact Lense, Interleukin-6, Ocular Inflammation, Non Invasive-Tear Break Up Time, Tear Meniscus,

Optical coherence tomography

Abstract: Background: Contact lenses were increasing use worldwide. Silicone hydrogel material was proposed to be

safe for overnight Soft Contact Lens wear. This study aim to evaluate IL-6 levels, conjuctival inflammation,

tear function and tear menisci parameters after overnight wear of silicone hydrogel Soft Contact Lens and

compare with daily wear of hydrogel SCL. A randomized controlled trial carried out in myopia subjects,

treated using daily hydrogel (Nefilcon-A) SCL in one eye, and overnight silicone hydrogel (Lotrafilcon-B)

SCL in the fellow eye for 14 days. The slit lamp examination, NIBUT, Schirmer test, tear menisci measured

with OCT, and tear sampling for IL-6 were performed before and after SCL wear. One hundred and for eyes

from 52 subjects were included. The tear IL-6 significantly increases 6.37 pg/mL in Lotrafilcon-B and 4.46

pg/mL in Nefilcon-A. There were no significant conjunctival hyperemia changes in both groups (p=1.000)

nor significant correlation of tear IL-6 levels and conjunctival hyperemia (p = 0.234). The NIBUT of both

groups were decrease significantly (p=0.000). The Schirmer I were not significant changes after SCL wear.

The tear meniscus height were not significantly decrease in both groups. The tear meniscus area were

decrease significantly 1,181.5 μm2 in the the Lotrafilcon-B group and 1,795.0 μm2 in the Nelfilcon-A group.

The tear meniscus volume were decrease 0.08 μL in the the Lotrafilcon-B 0.05 μL in the Nelfilcon-A

group.The correlation between NIBUT, Schirmer I test and tear menisci parameter was not significant. Two

weeks of daily hydrogel and weekly silicone hydrogel SCL wear comparably increases tear IL-6, did not

increase conjunctival hyperemia, decreases NIBUT, tear menisci, without significant alterations in Schirmer.

1 INTRODUCTION

Prevalence of contact lens (CL) wear is increasing

with many reason.1–3 Increasing prevalence of

myopia4,5 lead to the increase of contact lens wear.

International contact lens prescribing in 2019 data4

shows that the mean age at fitting was in early 30s

(32.8 ± 14.9 years) and even younger in Asian

markets. Soft contact lens (SCL) was prescribed for

87%. Conventional hydrogel SCLs were prescribe for

21% daily wear CL patients compare to 57% of

silicon hydrogel for daily wear CL patients. Only 7%

https://orcid.org/0000-0000-0000-0000

extended wear SCLs were prescribed by the

practitioners.5 However, due to patient's need to have

good visual acuity over the time, then emerges

demand on overnight or extended wear (EW) SCL.

Contact lens wear can lead to complications

including corneal hypoxia, inflammation, contact

lens related discomfort and dryness.1,6 Conjunctival

hyperemia was one of its inflamation signs. It was

resulted by increase vascular permeability that were

often ascociated with tear Interlukin (IL)-6.7,8 Tear

IL-6 level in soft contact lens wearer have been

evaluated in some studies.8–12

Rahayu, T., Adisti, ., Puspitasari, W. and Mardianto, U.

Comparison of Tear Interleukin-6 level, Conjunctival Inﬂammation, and Tear Film Function in Daily Conventional Hydrogel and Extended Silicone Hydrogel Contact Lens Wear.

DOI: 10.5220/0010489401550163

In Proceedings of the 1st Jenderal Soedirman International Medical Conference in conjunction with the 5th Annual Scientiﬁc Meeting (Temilnas) Consortium of Biomedical Science Indonesia

(JIMC 2020), pages 155-163

ISBN: 978-989-758-499-2

155

Silicone hydrogel material was developed to

increase CL oxygen permeability. It is important to

prevent cornea hypoxia due to overnight CL wear

however, the addition of hydrophobic silicone

components lower the SCL wettability and cause

discomfort. Surface treatment makes SCL surface

becomes more hydrophilic, more comfortable to

wear, decrease dry eyes risk.6 On the other hand,

contact lenses made from conventional hydrogel

material need to have a high water content to increase

its oxygen permeability. High water content is related

to SCL dehydration and protein deposit that can cause

decrease of pre- and post-lens tear layer.13–15 Such

condition can cause low wettability and make tear

easier be evaporated.

SCL wearing duration could also affect tear layer

function. Fahmy et al16 reported that Daily Wear

(DW) SCL is more comfortable than weekly/monthly

wear with the same SCL. Similar result was found in

SiHy SCL with increased comfort in DW rather than

Extended Wear (EW).17

Evaluating tear film functions could be performed

with measuring Non-Invasive Break Up Time

(NIBUT), Schirmer, and tear volume.18,19 Tear

meniscus could be assess non invasively with Optical

Coherence Tomography (OCT). It was reported OCT

have a great precision to measure tear meniscus.

As far as our knowledge, there is no prior study

that evaluate the inflamation rate of SCL users with

an appropriate manner of SCLs wearing schedule

based on it’s material oxygen permeability. The aim

of this study to compare the effect of weekly wear of

silicon hydrogel SCL and daily wear conventional

hydrogel SCL on tear IL-6 level, conjunctival

inflammation, tear film functions, and the correlation

among that parameters.

2 MATERIAS AND METHODS

The subjects were recruited with inclusion criteria of

low to moderate myopia (-0.50 to -6.00 Diopters) and

astigmatism less than 1 diopters, subjects with 6/6

BCVA on both eyes, aged ≥18-35 years, had a good

general condition and were able to undergo a follow-

up procedure. The subjects with abnormal corneal

topography, have a disease or history of allergic or

atopic disease, NIBUT less than 10 seconds, work in

exposure to chemicals, smoke, hazardous gases, and

welding / flame sparks were excluded. Subjects who

did not come for follow up according to the schedule

determined by the researcher, resigned while the

research was in progress, experiencing severe

inflammation or infection in the eye, or did not use

SCL according to the instructions given by the

researcher consider to be drop out from the study.

Ethical clearance was obtained from the Ethics

Committee of the Faculty of Medicine Universitas

Indonesia (N0: KET-

135/UN2.F1/ETIK/PPM.00.02/2019).

Conjunctival inflammation with the was assessed

based on slit lamp camera photos by 2

ophthalmologist. The assessment was carried out

using the Efron Grading System.20 If there is a

difference of opinion between the two assessors, the

value taken is the highest grading number. Tear

samples were taken before and 14 days after SCL

wear. The tear IL-6 was examined at Biochemistry

Laboratory Faculty of Medicine, Universitas

Indonesia using the Human Interleukin-6 Elisa Kit

Coma Biotech® Quote JC5607 Product No.

K0331194 from Indonesian Genetics Science LLC.

The NIBUT was measured with Tearscope-plus®

(Keeler, Windsor, UK), determined by the time

(second) of Tearscope mirres on the cornea break

after blink. Schirmer I test was performed using

Schirmer test strips. Tear meniscus examination was

measured 3 times, 20-60 minutes, 7 days, and 14 days

after using SCL by measuring tear meniscus hight

(TMH) and tear meniscus area (TMA) using anterior

OCT of Cirrus™-HD OCT 5000, Carl Zeiss,

Germany. Manual measurement with ImageJ

software was used to measure TMV. Assessments

were done 3 times, 20-60 minutes, 7 days, and 14

days after using SCL. All the examiner were blinded

to the type of the SCL worn by the subjects.

3 RESULTS

There were 52 subjects (104 eyes) included to this

study, 10 subjects are male and 42 are female. The

mean age of subjects is 22.12±1.79 years.

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Figure 1. Scheme of Recruitment

Table 1. Clinical Characteristics data of Subjects in Two Groups

Parameter

Nefilcon A Lotrafilcon B

P value

Mean / Med (SD / Range) Mean / Med (SD / Range)

UCVA 0,40 (0,02 - 0,86) 0,50 (0,03 - 0,86) 0,386*

Spher (D) -1,25 (-6,00 - -0,50) -1,00 (-6,00 - -0,50) 0,169*

Cyl (D) -0,25(-1,25 - 0,00) -0,25 (-1,25 - 0,00) 0,399*

SCL (D) -1,25 (-6,00 - -0,50) -1,00 (-6,00 - -0,50) 0,059*

K1 (D) 42,93 (± 1,27) 42,92 (± 1,23) 0,697

K2 (D) 44,03 (± 1,23) 44,08 (± 1,22) 0,364

IL-6 pre (pg/ml) 1,24 (0,04 - 160,10) 0,95 (0,04 - 171,02) 0,695*

NIBUT 14,70 (± 3,72) 16,76 (± 5,05) 0,001

Table 2. The IL-6 Tear Level Before and After SCL wear between Groups

Parameter

Nefilcon A Lotrafilcon B

P value*

Median (Range) pg/ml Median (Range) pg/ml

IL-6 pre 1,24 (0,04 - 160,10) 0,95 (0,04 - 171,02) 0,695

IL-6 post 5,97 (0,07 - 698,95) 12,66 (0,11 - 1118,59) 0,101

IL-6 increase 4,46 (0,01 – 685,40) 6,37 (0,05 – 1115,8) 0,117

Comparison of Tear Interleukin-6 level, Conjunctival Inﬂammation, and Tear Film Function in Daily Conventional Hydrogel and Extended

Silicone Hydrogel Contact Lens Wear

157

Figure 2. Comparison between IL-6 levels before and 14 days after daily use Neflicon A and weekly use of Lotrafilcon B

Lotrafilcon B were used in 21 eyes and 31 left eyes

while Nefilcon A were used in 31 right eyes and 21

left eyes. Two subjects were dropped out due to non-

compliance of SCL wear and lost to follow-up. Data

analysis was carried out in 100 eyes of 50 subjects, 50

eyes with Nefilcon A daily wear and 50 eyes with

Lotrafilcon B overnight wear (figure 2).

There is no significant difference in UCVA,

spherical and cylindical power correction,

keratometric value, and IL-6 tear levels between

groups before using SCL. The NIBUT value of

subjects in Lotrafilcon group was significantly higher

compare to those in Nefilcon group. However the

difference is not clinically significant, since the mean

NIBUT value of both group are in normal range.

(tabel 1).

There is a significant increase of tear IL-6

level after 14 days SCL wear in both groups

(p=0.000). However, there were no significant

differences in the delta IL-6 tear levels between

groups as seen in Table 2. The increasing tear IL-6

levels in weekly Lotrafilcon B SCL wearer seems

higher compare to those in daily Nefilcon A SCL

wearer. However, the difference is not statistically

signifinat. Figure 2.

There is no significant differences in

conjunctival inflammation, determined with Efron’s

Grading System, betwen two groups of SCL wearer

before and after 14 days using SCL as well

(p=0.000).The difference of conjunctival

inflammation changes was also not statistically

significant between two groups of SCL wearer (figure

3). Table 3 and 4 shows that the correlation between

tear IL-6 and conjunctival inflammation was not

significant. There was significant decrease the mean

of NIBUT in both groups after 14 days SCL wear.

The mean of NIBUT value changes were 3.4 seconds

in Nefilcon A daily SCL wear and 4.6 seconds in

Lotrafilcon B weekly SCL wear. The NIBUT

decrease after 14 days Lotrafilcon weekly SCL wear

was significantly greater rather than that in Nefilcon

daily SCL wear (p=0.008, Wilcoxon rank test). There

were no significant difference of Schirmer I change

before and after SCL wear between groups, that were

0.41 mm (-6.0 – 7.0 mm) in Nefilcon A group and

0.69 mm (-10 – 10 mm) in Lotrafilcon B group (p=

0.401, Wilcoxon rank test).

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Degrees changes -1:One degree down, 0:No changes, 1:Increases by 1 degree, 2:increase by 2 degrees

Figure 3. Changes in the degree of conjunctival inflammation before and after daily use of Nefilcon A LKL and weekly use

of Lotrafilcon B

Table 3. Correlation between conjunctival bulbar inflammation and changes in IL-6 levels

Conjunctival

inflammation

(Efron’s Grade)

Nefilcon A Lotrafilcon B

P value*

Tear IL-6 Median

(Range)

Tear IL-6 Median

(Range)

(1) 9 0,38 (0,02 - 685,40) 10 4,61 (0,06 - 230,30) 0,243

(2) 40 4,60 (0,01 - 120,46) 36 5,61 (0,05 - 1115,80) 0,905

(3)** 1 8,48 (8,48 - 8,48) 4 15,7 (2,45 - 29,77) ----

*Mann Whitney rank. ** Not tested

Table 4. Correlation between conjunctival limbal inflammation and changes in IL-6 levels

Conjunctival

inflammation

(Efron’s Grade)

Nefilcon A Lotrafilcon B

P value*

Tear IL-6

Median (Ran

Tear IL-6

Median (Ran

(0) 1 0,13( 0,13 - 0,13) 0 ------ ----

(1) 46 4,46 (0,01 - 685,40) 47 7,03 (0,05 - 1115,8) 0,424

(2) ** 3 26,5 (0,05 - 120,46) 2 1,35 (0,83 - 1,87) ----

(3) ** 0 ------ 1 29,8 (29,8 - 29,8) ----

Comparison of Tear Interleukin-6 level, Conjunctival Inﬂammation, and Tear Film Function in Daily Conventional Hydrogel and Extended

Silicone Hydrogel Contact Lens Wear

159

Nelfilcon A; Anova p=0.236

Lotrafilcon B; Anova p=0.476

Figure 3. Tear Meniscus Height mean value at day 0, day 7, and day 14 evaluation

Nelfilcon A: Anova p=0.001 0 vs 7 : p=0.085 7 vs 14: p=0.116 0 vs 14: p=0.000

Lotrafilcon B: Anova p=0.003 0 vs 7 : p=0.058 7 vs 14: p=0.548 0 vs 14: p=0.003

Figure 4. Tear Meniscus Area mean value changes from initial to day 14 evaluation

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Nelfilcon A: Anova p=0,002 0 vs 7 : p=0,116 0 vs 14: p=0,001 7 vs 14: p=0,216

Lotrafilcon B: Anova p=0,005 0 vs 7 : p=0,073 0 vs 14: p=0,004 7 vs 14: p=0,56

Figure 5. TMV mean value changes from initial evaluation to day 14 evaluation

There are no significant TMH decrease in both

Nelfilcon A group (p=0.236, Anova test) and

Lotrafilcon B group (p=0.476, Anova test)(figure3).

There is also no significant diference TMH decrease

between group (p=0.556, Wilcoxon rank test).

There were significant decreases in mean of TMA

value after day 14 days of SCL wear, which are

1.795,0 μm2 in Nelfilcon A group and 1,181.5 μm2

in Lotrafilcon B group (figure 4). The decreases of

TMA between group have no significant difference

(p= 0.898, Wilcoxon rank test).

Changes in TMV mean value on both groups were

also found insignificantly different (p>0.05).

Changes in TMV mean value for Nelfilcon A and

Lotrafilcon B groups after 14 days are -0.08 μL and -

0.05 μL. These results were statistically insignificant

(p= 0.342). Figure 5 showed significant decrease of

TMV after 14 days wearing SCL, while the decrease

after 7 days wearing SCL was found insignificant.

Spearman correlation test was carried out in this

study. It is found that neither in group Nelfilcon A or

Lotrafilcon B was found significant correlation

between NIBUT or Schirmer 1, both initial and final

evaluation results, and TMH, TMA, and TMV both

initial and final evaluation results (r < ±0,3).

4 DISCUSSION

The level of IL-6 in tears increased significantly after

14 days SCL in both groups (p=0,000). However, the

difference in the increase of that was not significant

between groups (p=0.117). It could be proposed that

14 days of silicon hydrogel weekly overnight SCL

wear have equally effect in tear IL-6 levels increase

with daily conventional hydrogel SCL wear. Poyraz

et al9 found that increasing IL-6 values in

conventional hydrogel SCL users and silicone

hydrogel SCL wearer did not have significant

differences. In Poyraz’s study both SCL types were

used daily.

The conjuctival hyperemia of the subjects in this

study were not significantly changed before and after

14 days SCL wear, both in Nefilcon A group

(p=1.000) and Lotrafilcon B group (p=1.000). Fonn

et al21 reported that subjects using conventional

hydrogel SCL shows significantly higher increase

conjunctival injection compare to that who use silicon

hydrogel SCL. The effects difference of SCL wear in

Fonn’s study was probably caused by both type of

SCL with different Oxygen permeability were use for

overnight wear. Brennan et al22 found that

conventional hydrogel weekly SCL wearer showed a

significant higher level of conjunctival inflammation

compare to silicon hydrogel SCL wearer. Covey et

al23 reported the level of inflammation in high Dk

Comparison of Tear Interleukin-6 level, Conjunctival Inﬂammation, and Tear Film Function in Daily Conventional Hydrogel and Extended

Silicone Hydrogel Contact Lens Wear

161

silicone hydrogel SCL wearer were the same as in

normal not wearing SCL eyes, it was grade 2 (mild),

similar with our study. This suggests that 14 days of

properly SCL wear did not triger a significant

conjunctival inflammation yet.

There is no significant correlation between

elevated tear IL-6 levels with conjunctival

inflammation found in this study. Significant increase

in tear IL-6 after 14 day SCL wear was not followed

by an increase in conjunctival vascular injection.

Same findings were reported by Enrique de

Salamanca et al24 and Kalsow et al25, who suggest

that an increase in cytokines on the ocular surface

often occurs before the appearance of clinical

symptoms. Dogru et al8 reported that 2 weeks daily

use of silicone hydrogels SCL has a close relationship

with increased IL-6 in tears wich is not accompanied

by significant changes in the surface damage of the

conjunctiva or cornea, as well as changes in

keratoconjunctival cell morphology.

Soft Contact Lens wear could induce CLIDE,

because it increases evaporation, disturbs tear film

stability6,14 and alters tear production. Conventional

hydrogel SCL may cause CLIDE due to its high water

content, protein deposit, low wettability, and friction

between SCL and ocular surface.6,18,26 Meanwhile,

silicone hydrogel SCL that is more hydrophobic, have

lower wettability, and its extended wearing could

increase the risk of CLIDE.

The subjects of both groups experience

significant decrease of NIBUT after 2 weeks using

both SCL. This finding is similar to previous

studies.8,27,28 Weekly overnight Lotrafilcon B wear

dcreases NIBUT significantly greater compare to

daily Nefilcon A SCL wear (p=0.008). SCL wear

could intervere physiological quality of tear film due

to evaporation.8,14

We found no significant changes in Schirmer I

results after 14 days SCL wear in both group.

Iskeleli29 also found no decrease in Schirmer I

evaluation after 3 months of Lotrafilcon A and

Lotrafilcon B SCL wear. Other study by Dogru et al8

found no significant decrease after 2 weeks using

daily wear silicon hydrogel SCL.

There was no significant decrease of TMH after 2

weeks using both type of SCL. There was also no

significant difference of TMH decrease between the

two groups. This findings was similar with

Santodomingo-Rubido et al11 that found no

significant TMH difference between 4 groups of

Silicon Hydrogel wear for 1, 3, 6, 12, and 18 months.

Tear Meniscus Area was not significanty decrease

after 2 weeks using SCL, with no significant

difference between groups. Wang et al30 found no

significant decrease in TMA after 20 minutes using

two SCL types. Wang et al used 20 adapted subjects

using Balafilcon A on one eye and Galyfilcon A on

the other eye.

Our study found that both daily wear conventional

hydrogel and weekly silicone hydrogel SCLs waer

significantly decreases TMV after 2 weeks with no

significant difference between group. This is

accordance to study by Wang30 that found no

significance difference in TMV decrease in adapted

subjects after 20 minutes and 4 hours using SCL.

We found no correlation between NIBUT and

Schirmer I examination, both groups. Wang et al also

found no correlation between NIBUT and tear

volume which was assessed with fluorometry.31 It is

proposed that NIBUT shows tear film stability, not

tear quantity.

The correlation between Schirmer I and tear

menisci parameters has been studied both in normal

and dry eyes populations. Raj A et al32 evaluated tear

menisci in normal population using Fourier Domain

OCT and showed no correlation between Schirmer 1

and TMH. This result may be affected by Schirmer 1

method that used direct contact to eye so it affected

secretion reflex and tear base. Meanwhile, evaluation

with OCT used non-invasive method to measure tear

menisci at one time.

5 CONCLUSIONS

Tear IL-6 level increased significantly after 14 days

daily conventional and weekly silicone hydrogel SCL

wear. The increased tear IL-6 level occur before the

increase conjunctival hyperemia. The NIBUT,

Schirmer I, and tear menisci parameters have each

functions that can be replaced by one another. After 2

weeks of using daily wear Nefilcon A and weekly

Lotrafilcon B SCLs decereases the NIBUT and Tear

Meniscus Volume. It is suggested to evaluate tear

stability in long term SCL wearer.

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