ArticlePDF Available

Abstract and Figures

Purpose: To evaluate the performance of medical contact lenses (CLs) for a wide range of clinical indications. Design: Prospective cross-sectional study. Methods: A total of 281 eyes were evaluated in 281 consecutive patients (≥18 years of age; CL use ≥3 months) who visited the contact lens service in a tertiary academic clinic for a scheduled follow-up visit. The main outcome measured were clinical indications for CL wear; CL type; change in corrected distance visual acuity (CDVA) with CL use; CL wearing duration; CL wearing time; subjective performance measured using a visual analog scale (VAS) questionnaire (score range: 0-100); and effectiveness of the lens-selection algorithm. Results: Wearing CLs significantly improved CDVA compared to wearing spectacles (median change: -0.15 logMAR, range: 1.00 to -2.10; P<.001). Daily-wear CLs were worn by 77% of patients for a median of 15h/day (range: 5-18h/day), median 7 days/week (range: 1-7 days/week). High subjective scores were measured, with similar results obtained between the scleral lens and soft lens groups. The medical CL fitting was found to be generally effective (the overall satisfaction rating was ≥70 for 81% of patients). Conclusions: Fitting CLs based on the lens-selection algorithm yielded positive clinical results, including improved visual acuity, satisfactory wearing time, and high overall subjective performance. Moreover, subjective performance was similar between users of scleral lenses and users of soft lenses. These results underscore the importance of prescribing scleral lenses and the need for tertiary eye clinics to offer patients a variety of CL types.
Content may be subject to copyright.
Objective
and
subjective
evaluation
of
the
performance
of
medical
contact
lenses
tted
using
a
contact
lens
selection
algorithm
Esther-Simone
Visser
a,
*,
Robert
P.L.
Wisse
b
,
Nienke
Soeters
b
,
Saskia
M.
Imhof
b
,
Allegonda
Van
der
Lelij
b,c
a
Visser
Contact
Lens
Practice,
Department
of
Ophthalmology,
University
Medical
Center
Utrecht,
Room
L.02.628,
Postbus
85500,
3508
GA
Utrecht,
The
Netherlands
b
Department
of
Ophthalmology,
University
Medical
Center
Utrecht,
Postbus
85500,
3508
GA
Utrecht,
The
Netherlands
c
Department
of
Ophthalmology,
Central
Military
Hospital
Utrecht,
Postbus
90000,
3509
AA
Utrecht,
The
Netherlands
A
R
T
I
C
L
E
I
N
F
O
Article
history:
Received
8
October
2015
Received
in
revised
form
17
December
2015
Accepted
4
February
2016
Keywords:
Lens
selection
algorithm
Scleral
lenses
Medical
contact
lenses
Keratoconus
Dry
eye
disease
Keratoplasty
A
B
S
T
R
A
C
T
Purpose:
To
evaluate
the
performance
of
medical
contact
lenses
(CLs)
for
a
wide
range
of
clinical
indications.
Design:
Prospective
cross-sectional
study.
Methods:
A
total
of
281
eyes
were
evaluated
in
281
consecutive
patients
(18
years
of
age;
CL
use
3
months)
who
visited
the
contact
lens
service
in
a
tertiary
academic
clinic
for
a
scheduled
follow-up
visit.
The
main
outcome
measured
were
clinical
indications
for
CL
wear;
CL
type;
change
in
corrected
distance
visual
acuity
(CDVA)
with
CL
use;
CL
wearing
duration;
CL
wearing
time;
subjective
performance
measured
using
a
visual
analog
scale
(VAS)
questionnaire
(score
range:
0100);
and
effectiveness
of
the
lens-selection
algorithm.
Results:
Wearing
CLs
signicantly
improved
CDVA
compared
to
wearing
spectacles
(median
change:
0.15
logMAR,
range:
1.0 0
to
2.10;
P<.001).
Daily-wear
CLs
were
worn
by
77%
of
patients
for
a
median
of
15
h/day
(range:
518
h/day),
median
7
days/week
(range:
17
days/week).
High
subjective
scores
were
measured,
with
similar
results
obtained
between
the
scleral
lens
and
soft
lens
groups.
The
medical
CL
tting
was
found
to
be
generally
effective
(the
overall
satisfaction
rating
was
70
for
81%
of
patients).
Conclusions:
Fitting
CLs
based
on
the
lens-selection
algorithm
yielded
positive
clinical
results,
including
improved
visual
acuity,
satisfactory
wearing
time,
and
high
overall
subjective
performance.
Moreover,
subjective
performance
was
similar
between
users
of
scleral
lenses
and
users
of
soft
lenses.
These
results
underscore
the
importance
of
prescribing
scleral
lenses
and
the
need
for
tertiary
eye
clinics
to
offer
patients
a
variety
of
CL
types.
ã
2016
British
Contact
Lens
Association.
Published
by
Elsevier
Ltd.
All
rights
reserved.
To
treat
a
wide
range
of
ocular
diseases,
modern-day
eye-care
practitioners
have
a
growing
arsenal
of
medical
contact
lenses
(CLs).
The
primary
optical
indication
for
tting
a
patient
with
medical
CLs
is
to
improve
visual
acuity
in
cases
of
high
refractive
error
and/or
irregular
astigmatism
[1];
less
common
indications
include
anisometropia,
nystagmus,
and
occlusion
[2].
In
a
clinical
setting,
another
important
indication
for
CL
use
is
for
therapeutic
purposes
(e.g.,
in
the
case
of
a
corneal
bandage,
in
which
the
cornea
is
physically
protected
from
the
environment
in
order
to
improve
hydration,
promote
corneal
healing,
and
relieve
pain)
[310].
Often,
several
effects
are
desired
[4,6].
All
of
these
applications
have
specic
requirements
with
respect
to
the
lenses
design
and
material.
A
wide
variety
of
CL
types
are
currently
available,
including
conventional
soft
lenses,
silicone
hydrogel
lenses,
rigid
gas-permeable
(RGP)
corneal
lenses,
scleral
lenses,
hybrid
lenses,
occlusive
lenses,
iris
print
lenses,
lter
lenses,
piggyback
systems,
and
scleral
prosthetics.
Tailoring
a
CL
to
adequately
t
the
patients
needs
requires
a
trained
eye-care
practitioner.
Clinical
applications
for
CLs
have
expanded
due
to
improve-
ments
in
the
materials
used
(for
example,
lens
materials
that
are
more
oxygen-permeable)
[3]
and
recent
innovations
in
lens
design,
including
custom-made
specialized
lenses
[11,12],
and
toric-
and
tangential
scleral
lens
designs
[1315].
In
turn,
these
developments
have
altered
the
prescription
habits
of
eye-care
practitioners.
For
example,
the
improved
material
properties
of
silicone
hydrogels
has
led
to
a
major
shift
from
conventional
soft
lenses
to
silicone
hydrogel
lenses
[5,8].
More
interestingly,
the
increased
availability
of
custom-designed
contact
lenses
for
patients
with
keratoconus
*
Corresponding
author.
E-mail
address:
esvisser@vissercontactlenzen.nl
(E.-S.
Visser).
http://dx.doi.org/10.1016/j.clae.2016.02.006
1367-0484/ã
2016
British
Contact
Lens
Association.
Published
by
Elsevier
Ltd.
All
rights
reserved.
Contact
Lens
and
Anterior
Eye
xxx
(2015)
xxxxxx
G
Model
CLAE
877
No.
of
Pages
9
Please
cite
this
article
in
press
as:
E.-S.
Visser,
et
al.,
Objective
and
subjective
evaluation
of
the
performance
of
medical
contact
lenses
tted
using
a
contact
lens
selection
algorithm,
Contact
Lens
&
Anterior
Eye
(2016),
http://dx.doi.org/10.1016/j.clae.2016.02.006
Contents
lists
available
at
ScienceDirect
Contact
Lens
and
Anterior
Eye
journal
homepage:
www.else
vie
r.com/locat
e/clae
or
keratoplasty
[11,1620]
has
been
accompanied
by
a
large
increase
in
the
use
of
scleral
lenses
[2123].
Scleral
lenses
play
an
important
role
in
medical
CL
practice,
particularly
in
cases
in
which
other
lens
designs
have
suboptimal
results,
for
example
in
the
case
of
unstable
lens
tting,
poor
tolerance,
unsatisfactory
visual
improvement,
and/or
unsatisfactory
corneal
bandage.
However,
the
ability
to
t
scleral
lenses
requires
specic
skills
and
training.
Another
factor
that
has
hampered
the
popularity
of
scleral
lenses
is
prejudicewith
respect
to
poor
handling
of
scleral
lenses
and
a
lack
of
comfort
for
the
user.
Recently,
Van
der
Worp
etal.
[21]
and
Schornack
[22]
reviewedthe
outcomesof
studies
using
scleral
lenses,
and
several
studies
have
evaluated
the
tting
of
medical
CLs
in
specic
settings
[1,3,5,7,19,24].
However,
no
overarching,
evidence-based
method
for
tting
the
optimal
CL
type
in
more
challenging
clinical
cases
is
currently
available.
In
addition,
the
patients
subjective
experiences
based
on
these
various
treatment
strategies
also
warrant
attention.
Our
goal
was
to
evaluate
the
experiences
of
CL
practitioners
and
patients
in
a
large,
tertiary
clinic.
Thus,
we
prospectively
evaluated
the
outcomes
of
medical
CL
tting
in
which
the
lens
type
is
based
on
a
practical
lens
selection
algorithm,
and
we
examined
the
clinical
outcomes
and
patient
satisfaction
in
response
to
the
strategies
chosen.
Importantly,
the
comprehensive
lens
selection
algorithm
enables
practitioners
to
achieve
desirable
results.
1.
Methods
In
this
prospective
observational
study,
we
included
all
consecutive
patients
(in
total
281
patients)
who
visited
the
Contact
Lens
service
(Visser
Contact
Lens
Practice)
at
the
University
Medical
Center
Utrecht
from
August
2014
through
October
2014
for
a
follow-up
for
a
medically
indicated
CL.
The
inclusion
criteria
were
18
years
of
age
and
CL
use
for
3
months
prior
to
enrollment.
The
exclusion
criteria
were
patients
who
came
for
an
emergency
visit
or
patients
who
were
unable
or
unwilling
to
participate.
Our
institutions
Ethics
Review
Board
(Medisch
Ethische
Toetsingscommissie)
ruled
prospectively
that
approval
was
not
required
for
this
study;
however,
all
participating
patients
provided
written
informed
consent.
All
procedures
were
per-
formed
in
accordance
with
the
Declaration
of
Helsinki
and
with
local
laws
regarding
research
on
human
subjects.
During
the
study
visit,
the
primary
and
secondary
clinical
indication
for
CL
use,
CL
type,
and
CL
history
were
recorded;
in
addition,
the
following
data
were
obtained
from
the
patients
medical
history:
the
presence
of
allergies
and/or
eczema,
the
use
of
topical
eye
drops
(e.g.,
lubricants,
prophylactic
antibiotics,
steroids,
glaucoma
eye
drops,
anti-allergy
eye
drops,
or
other
eye
drops),
and
average
CL
wearing
time.
Best
corrected
distance
visual
acuity
(CDVA)
was
measured
as
Snellen
visual
acuity
both
with
(CL
CDVA)
and
without
(spectacle
CDVA)
CLs.
All
patients
were
also
instructed
to
complete
a
questionnaire
covering
the
following
four
specic
topics:
lens
comfort,
visual
quality,
lens
handling,
and
overall
satisfaction
with
their
lenses.
Scores
were
obtained
on
a
visual
analog
scale
(VAS);
the
scores
ranged
from
0
(unacceptable
performance)
to
100
(excellent
performance).
This
questionnaire
was
used
in
our
previous
studies,
and
approval
for
using
it
here
was
granted
by
the
Research
and
Ethics
Committee
of
the
City
University,
London,
United
Kingdom
SiHy / Soft lens
*1,3-5,7,8,12,18,27
Corneal RGP
*11,12,18,19,24
Primary indication
Bandage
Tear film deficiency
Mild Moderate Advanced
Ye
s
Yes
Yes
Yes Ye s Yes
No
No
No
No No No
Elevated corneal scar
• Severe dry eye disease or
• Severe lagophthalmos or
• Cicatrizing eye disease or
• Moderate / advanced
irregular astigmatism
Corneal irregularity
Hybrid
*12,17-19,20
Piggyback
*12,20
Scleral lens
*4,12,15,21,22,25,27-2
9
Fig.
1.
Contact
lens
selection
algorithm.
Description:
A
selection
algorithm
for
selecting
contact
lenses
for
two
principal
medical
uses:
irregular
astigmatism
and
bandage.
SiHy
=
silicone
hydrogel;
RGP
=
rigid
gas-permeable.
*
=
references
listed
in
the
main
reference
list.
Mild
corneal
irregularity
=
acceptable
subjective
visual
quality
with
SiHy;
Moderate
corneal
irregularity
=
unacceptable
subjective
visual
quality
with
SiHy,
acceptable
lens
t
with
RGP
corneal;
Advanced
corneal
irregularity
=
unacceptable
subjective
visual
quality
with
SiHy,
no
acceptable
lens
t
with
RGP
corneal.
Note:
The
grading
of
severe
dry
eye
included
grade
IV
and
V
based
on
the
Oxford
Index
for
staining
and
tear
lm
break-up
time
[30].
SiHy
or
RGP
corneal
trial
lenses
were
used
to
determine
the
grade
of
mild,
moderate,
or
advanced
corneal
irregularity.
2
E.-S.
Visser
et
al.
/
Contact
Lens
&
Anterior
Eye
xxx
(2015)
xxxxxx
G
Model
CLAE
877
No.
of
Pages
9
Please
cite
this
article
in
press
as:
E.-S.
Visser,
et
al.,
Objective
and
subjective
evaluation
of
the
performance
of
medical
contact
lenses
tted
using
a
contact
lens
selection
algorithm,
Contact
Lens
&
Anterior
Eye
(2016),
http://dx.doi.org/10.1016/j.clae.2016.02.006
[25,26].
Patients
with
a
visual
acuity
score
of
<1/300
(i.e.,
<distinguish
hand
motion)
did
not
complete
the
questions
regarding
visual
quality;
CVDA
was
also
not
evaluated
in
these
patients.
Patients
with
continuous-wear
bandage
lenses
were
omitted
from
the
lens
handling
section
of
the
questionnaire,
as
their
lenses
were
replaced
by
our
contact
lens
service;
lens
wearing
time
was
also
not
determined
in
these
patients.
Patients
with
continuous-wear
CLs
visited
the
practice
every
4
6
weeks
to
either
replace
or
clean
their
lenses,
and
they
were
prescribed
prophylactic
antibiotic
eye
drops
(chloramphenicol
0.5%,
minims
BID;
Bausch
&
Lomb).
All
other
patients
were
monitored
at
an
interval
that
met
their
specic
clinical
needs.
1.1.
Contact
lens
selection
The
selection
of
a
specic
CL
type
was
based
on
the
severity
of
the
disorder
and
the
presence
of
additional
indications
and/or
other
complicating
factors.
Our
CL
selection
algorithm
was
developed
for
two
principal
uses
for
medical
CLs:
irregular
astigmatism
and
bandage
(Fig.
1).
The
grading
of
severe
dry
eye
included
grade
IV
and
V
based
on
the
Oxford
Index
for
staining
and
tear
lm
break-up
time
[30].
A
grade
of
mild,
moderate,
or
advanced
corneal
irregularity
was
deter-
mined
based
on
CL
performance
and
acceptable
visual
quality:
SiHy
or
RGP
corneal
trial
lenses,
which
were
tted
in
accordance
with
the
manufacturers
guidelines,
were
used
to
assess
the
effects
of
corneal
irregularity.
The
grade
mild
refers
to
acceptable
subjective
visual
quality
with
a
SiHy
lens;
the
grade
moderate
refers
to
unacceptable
subjective
visual
quality
with
a
SiHy
lens
and
an
acceptable
lens
t
with
a
RGP
corneal
lens;
and
the
grade
advanced
refers
to
unacceptable
subjective
visual
quality
with
a
SiHy
lens
and
an
unacceptable
lens
t
with
a
RGP
corneal
lens.
A
grading
system
for
irregular
astigmatism
(based
on
absolute
values
measured
using
corneal
topography)
was
not
applicable
in
this
study,
as
the
actual
location
of
the
corneal
irregularity
or
cone
(i.e.,
central
or
peripheral)
can
have
a
signicant
inuence
on
CL
tting.
For
example,
an
advanced
centrally
located
keratoconus
might
benet
from
a
RGP
corneal
lens,
whereas
a
less
advanced
inferiorly
located
protrusion
might
impede
the
tting
of
an
RGP
corneal
lens,
thus
requiring
a
scleral
lens.
Our
approach
to
select
the
appropriate
type
of
soft
lens
(including
conventional
soft
lenses
or
silicone
hydrogel
lenses)
is
summarized
in
Fig.
2.
Indications
beyond
this
scope
(e.g.,
occlusion
lenses,
lter
lenses,
or
cosmetic
lenses)
were
not
included
in
the
lens
selection
algorithm,
as
these
types
of
lenses
are
directly
related
to
their
specic
indications.
Medical
refractive
indications,
including
high
refractive
error
(i.e.,
refractive
error
that
exceeded
10
diopters
[D]),
aphakia,
and
anisometropia,
were
tailored
to
the
individual
patients
needs.
The
best-tting
CL
material
and
design
was
prescribed
to
each
individual
patient
based
on
the
practi-
tioners
judgment
using
trial
lenses.
A
detailed
description
of
the
scleral
lens
tting
protocol
has
been
described
previously
[13,15,25].
In
brief,
tting
was
based
on
the
landing
of
the
scleral
lens
on
the
sclera
and
vaulting
of
the
lens
over
the
cornea
and
limbus.
Ideal
scleral
lens
tting
has
a
well-
balanced
haptic
bearing,
gentle
movement
of
the
lens
with
the
push-up
test,
and
adequate
corneal
and
limbal
clearance.
All
other
lenses
were
tted
in
accordance
with
the
applicable
manufac-
turers
protocols.
1.2.
Statistics
One
eye
in
each
subject
was
selected
at
random
using
an
autonomous
software
tool
(nQuery
Advisor,
version
7.0,
Statistical
Fig.
2.
Initial
and
advanced
selection
of
soft
lenses
for
medical
use
[32,33].
Description:
Flowchart
for
the
initial
and
advanced
selection
of
soft
lenses
(conventional
soft
or
SiHy
lenses)
for
medical
use.
SiHy
=
silicone
hydrogel.
*
=
references
listed
in
the
main
reference
list.
E.-S.
Visser
et
al.
/
Contact
Lens
&
Anterior
Eye
xxx
(2015)
xxxxxx
3
G
Model
CLAE
877
No.
of
Pages
9
Please
cite
this
article
in
press
as:
E.-S.
Visser,
et
al.,
Objective
and
subjective
evaluation
of
the
performance
of
medical
contact
lenses
tted
using
a
contact
lens
selection
algorithm,
Contact
Lens
&
Anterior
Eye
(2016),
http://dx.doi.org/10.1016/j.clae.2016.02.006
Solutions,
Cork,
Ireland).
All
Snellen
visual
acuity
values
were
converted
to
logMAR
values
for
statistical
calculations.
All
variables
were
tested
for
normal
distribution
using
the
Kolmogorov-Smirnov
test.
The
only
variable
that
was
found
to
be
distributed
normally
was
patient
age.
For
non-normally
distribut-
ed
paired
data,
the
Wilcoxon
signed
rank
test
was
used.
Differences
between
groups
were
analyzed
using
the
non-parametric
Kruskal-
Wallis
test
(for
continuous
outcomes),
the
Fishers
exact
test
(for
categorical
outcomes),
or
ANOVA
(age).
With
the
exception
of
patient
age
(which
is
reported
as
the
mean
and
standard
deviation),
all
summary
data
are
reported
as
the
median
and
range.
Subgroup
analyses
were
performed
on
the
following
stratied
data:
primary
clinical
indication
(keratoconus,
dry
eye
disease,
or
post-keratoplasty)
and
primary
CL
type
(scleral
lens
or
soft
lens).
Differences
with
a
P-value
<0.05
were
considered
statistically
signicant.
All
statistical
analyses
were
performed
using
SPSS
version
20.0
(IBM
Corp.,
Armonk,
NY,US).
2.
Results
This
study
included
281
eyes
from
281
patients;
160
patients
were
female
(57%),
and
142
eyes
were
right
eyes
(51%).
The
mean
age
of
the
patient
cohort
was
55
17
years
(range:
1893
years).
Slightly
more
than
half
of
the
patients
(n
=
158)
wore
CLs
in
both
eyes,
whereas
63
and
60
patients
wore
a
single
lens
in
the
right
or
left
eye,
respectively.
Thirty-four
percent
of
patients
presented
with
some
form
of
allergy,
and
15%
had
eczema.
Sixty-one
percent
of
patients
used
topical
eye
drops;
among
the
patients
who
used
eye
drops,
47%
used
a
lubricant,
24%
used
prophylactic
antibiotics,
15%
used
steroids,
7%
used
glaucoma
eye
drops,
5%
used
anti-allergy
eye
drops,
and
2%
did
not
specify
the
type
of
eye
drops
used.
2.1.
Clinical
indications
The
three
most
common
clinical
indications
in
our
study
cohort
were
keratoconus
(in
25%
of
cases),
dry
eye
disease
(23%),
and
keratoplasty
(20%).
The
primary
clinical
indications
and
the
CLs
applied
are
summarized
in
Table
1.
The
results
of
these
three
main
indication
groups
were
further
analyzed,
and
the
demographic
data
are
summarized
in
Table
2.
In
total,
26
of
the
281
eyes
(9%)
had
a
secondary
clinical
indication
for
CL
tting;
these
indications
included
dry
eye
disease
(n
=
5),
aniridia
(n
=
4),
decompensated
cornea
(n
=
3),
corneal
scarring
after
trauma
(n
=
3),
anisometropia
(n
=
2),
aphakia
(n
=
2),
high
refractive
error
(exceeding
+/10
D;
n
=
1),
corneal
scarring
after
infection
(n
=
1),
keratoplasty
(n
=
1),
corneal
dystrophy
(n
=
1),
recurrent
erosions
(n
=
1),
trichiasis
(n
=
1),
and
white
pupil
secondary
to
cataract
(n
=
1).
All
corneal
transplants,
with
the
exception
of
one
anterior
lamellar
keratoplasty,
were
perforating/penetrating
grafting
pro-
cedures.
Indications
for
transplant
surgery
included
keratoconus
Table
1
Clinical
indications
and
contact
lens
type.
Indication
No.
of
eyes,
n
(%)
Contact
lens
type
Scleral
Soft
RGP
Corneal
Occlusive
Iris
Filter
Other
a
Keratoconus
71
(25)
60
4
6
0
0
0
1
Dry
eye
disease
66
(23)
14
52
0
0
0
0
0
Keratitis
sicca
60
10
50
Keratitis
lagophthalmos
6
4
2
Keratoplasty
55
(20)
51
1
2
0
0
0
1
Corneal
scar
25
(9)
17
2
4
1
0
0
1
After
herpes
simplex
keratitis
9
6
2
1
After
other
infectious
keratitis
13
9
3
1
After
trauma
3
2
1
Refractive
19
(7)
3
11
2
0
1
2
0
High
refractive
error
>+/10
D
9
3
4
1
1
Aphakia
6
4
2
Anisometropia
4
3
1
Cornea
decompensation
17
(6)
0
14
0
0
1
2
0
Corneal
erosions
12
(4)
0
12
0
0
0
0
0
Other
irregular
astigmatism
5
(2)
3
0
2
0
0
0
0
After
surgery
(other
than
keratoplasty)
4
3
1
Unknown
cause
1
1
Miscellaneous
indications
11
(4)
0
3
1
4
2
0
1
Binocular
diplopia
3
3
Trichiasis
2
2
Aniridia
1
1
Entropion
1
1
Bulbus
atrophy
1
1
Iris
atrophy
1
1
Nystagmus
1
1
White
pupil
1
1
Total
no.
of
eyes,
n
(%)
281
(100)
148
(53)
99
(35)
17
(6)
5
(2)
4
(1)
4
(1)
4
(1)
D
=
Diopter;
RGP
=
rigid
gas-permeable.
a
Other
=
a
piggyback
system
for
keratoconus
(n
=
1),
a
hybrid
lens
for
keratoplasty
(n
=
1),
a
tinted
soft
keratoconus
lens
for
a
corneal
scar
after
trauma
(n
=
1),
and
a
prosthetic
scleral
lens
for
bulbous
atrophy
(n
=
1).
4
E.-S.
Visser
et
al.
/
Contact
Lens
&
Anterior
Eye
xxx
(2015)
xxxxxx
G
Model
CLAE
877
No.
of
Pages
9
Please
cite
this
article
in
press
as:
E.-S.
Visser,
et
al.,
Objective
and
subjective
evaluation
of
the
performance
of
medical
contact
lenses
tted
using
a
contact
lens
selection
algorithm,
Contact
Lens
&
Anterior
Eye
(2016),
http://dx.doi.org/10.1016/j.clae.2016.02.006
(n
=
24),
Fuchs
endothelial
dystrophy
(n
=
18,
all
of
which
were
performed
in
the
pre-endothelial
keratoplasty
era),
post-infectious
keratitis
scar
(n
=
8),
cornea
decompensation
(n
=
4),
and
unspeci-
ed
corneal
dystrophy
(n
=
1).
The
most
common
primary
clinical
reasons
for
applying
CLs
were
to
improve
visual
acuity
(in
63%
of
cases)
and
as
a
bandage
(34%).
A
small
number
of
patients
were
tted
with
CLs
for
cosmetic
purposes
(n
=
4),
occlusion
(n
=
3),
or
for
improved
contrast
vision
(n
=
1).
2.2.
Contact
lens
types
The
types
of
CLs
used
by
the
study
cohort
are
summarized
in
Table
1.
The
most
commonly
used
CLs
were
scleral
lenses
(in
53%
of
cases)
and
soft
lenses
(either
conventional
soft
lenses
or
silicone
hydrogel
lenses;
35%);
the
results
of
these
two
groups
were
analyzed
further.
The
scleral
lens
group
contained
patients
who
used
mini-scleral
lenses
(1518
mm
in
diameter;
n
=
20
patients)
or
regular
scleral
lenses
(1822
mm
in
diameter,
n
=
128
patients).
The
most
popular
soft
lenses
were
monthly
disposable
silicone
hydrogels
(n
=
65);
the
remaining
soft
lenses
were
3-month
disposable
silicone
hydrogels
(n
=
13),
daily
disposable
silicone
hydrogels
(n
=
7),
daily
disposable
soft
lenses
(n
=
4),
large-
diameter
soft
lenses
(n
=
4),
2-week
disposable
silicone
hydrogels
(n
=
2),
3-month
disposable
soft
lenses
(n
=
2),
monthly
disposable
soft
lenses
(n
=
1),
and
aphakia
soft
lenses
(n
=
1).
The
RGP
corneal
lens
designs
included
a
standard
corneal
design
(n
=
8),
a
keratoconus
design
(n
=
6),
and
a
keratoplasty
design
(n
=
3).
2.3.
Visual
acuity
outcomes
There
was
a
signicant
improvement
in
median
logMAR
CL
CDVA
(0.15;
range:
1.0 0
to
2.10)
compared
to
the
median
log
MAR
spectacle
CDVA
(P
<
0.001).
The
visual
outcomes
for
the
total
cohort,
the
major
clinical
indication
subgroups,
and
the
lens
subgroups
are
summarized
in
Table
3.
CDVA
improvement
by
CL
wear
differed
signicantly
between
the
major
indication
groups
(P
<
0.001,
Kruskal-Wallis
test);
specically,
CL
CDVA
improved
signicantly
more
in
the
patients
with
keratoconus
and
keratoplasty
compared
with
the
patients
with
dry
eye
disease.
Furthermore,
users
of
scleral
lenses
had
signicantly
more
CDVA
improvement
than
users
of
soft
lenses
(P
<
0.001,
Kruskal-Wallis
test).
Eighteen
of
the
281
eyes
(6%)
had
visual
acuity
that
was
<1/300
(i.e.,
<distinguish
hand
motion).
Table
2
Main
groups
of
clinical
indications:
general
data.
Indication
group
No.
of
eyes
Mean
age,
years
(range)
Gender,
%
male/female
Allergy,
n
(%)
Eczema,
n
(%)
Keratoconus
71
47
(2174)
47/54
33
(46)
19
(27)
Dry
eye
disease
66
59
(2087)
24/76
20
(30)
10
(15)
Keratoplasty
55
63
(2790)
51/49
19
(35)
5
(9)
Difference
between
the
three
indication
groups,
P-value
<0.001
a
=0.004
b
=.13
b
=0.03
b
a
Analysis
of
variance
(ANOVA)
test.
b
Fishers
exact
test.
Table
3
Spectacle
and
contact
lens
CDVA.
Indication
or
lens
group
No.
of
eyes
CDVA
1/300,
a
n
(%)
Spectacle
CDVA
Contact
lens
CDVA
CDVA
difference
P-value
b
Total
group
263
(94)
LogMAR
0.30
(2.52
to
0.10)
0.10
(2.52
to
0.20)
0.15
(1.00
to
2.10)
<0.001
Snellen
equivalent
20/40
20/25
N/A
N/A
Keratoconus
71
(100)
LogMAR
0.40
(2.52
to
0.10)
0.10
(1.00
to
0.10)
0.30
(0.12
to
1.70)
<0.001
Snellen
equivalent
20/50
20/25
N/A
N/A
Dry
eye
disease
64
(97)
LogMAR
0.10
(1.30
to
0.10)
0.07
(0.80
to
0.20)
0.00
(0.14
to
1.13)
=0.007
Snellen
equivalent
20/25
20/24
N/A
N/A
Keratoplasty
55
(100)
LogMAR
0.42
(2.520.00)
0.05
(2.22
to
0.10)
0.32
(0.15
to
2.10)
<0.001
Snellen
equivalent
20/53
20/22
N/A
N/A
Scleral
lenses
148
(100)
LogMAR
0.40
(2.52
to
0.10)
0.05
(1.30
to
0.20)
0.30
(0.15
to
2.10)
<0.001
Snellen
equivalent
20/50
20/22
N/A
N/A
Soft
lenses
88
(89)
LogMAR
0.19
(2.52
to
0.10)
0.12
(2.52
to
0.10)
0.00
(0.14
to
1.40)
=0.032
Snellen
equivalent
20/31
20/27
N/A
N/A
CDVA
=
corrected
distance
visual
acuity;
Log
MAR
=
logarithm
of
the
minimal
angle
of
resolution;
CDVA
outcomes
are
presented
as
median
(range);
N/A
=
not
applicable.
a
Distinguish
hand
motion.
b
Wilcoxon
signed
ranks
test.
E.-S.
Visser
et
al.
/
Contact
Lens
&
Anterior
Eye
xxx
(2015)
xxxxxx
5
G
Model
CLAE
877
No.
of
Pages
9
Please
cite
this
article
in
press
as:
E.-S.
Visser,
et
al.,
Objective
and
subjective
evaluation
of
the
performance
of
medical
contact
lenses
tted
using
a
contact
lens
selection
algorithm,
Contact
Lens
&
Anterior
Eye
(2016),
http://dx.doi.org/10.1016/j.clae.2016.02.006
2.4.
Wearing
time
and
duration
of
CL
use
Daily-wear
contact
lenses
were
worn
by
77%
of
patients,
with
a
median
of
15
h
per
day
(range:
518
h)
and
a
median
of
7
days
per
week
(range:
17
days).
The
remaining
23%
of
patients
wore
their
lenses
continuously;
these
lenses
were
either
silicone
hydrogels
(n
=
59)
or
soft
lenses
(n
=
6).
The
wearing
time
data
in
the
clinical
indication
and
lens
type
subgroups
are
summarized
in
Table
4.
In
our
cohort,
96%
of
patients
wore
their
CLs
8
h
per
day.
Among
the
patients
who
wore
their
CLs
<8
h
per
day,
5
used
scleral
lenses,
2
used
occlusive
lenses,
1
used
a
soft
lens,
1
used
a
tinted
soft
keratoconus
lens,
1
used
a
lter
lens,
and
1
used
a
prosthetic
scleral
lens.
The
median
duration
of
wearing
the
current
CL
type
was
6
years
(range:
3
months
to
39
years),
and
median
CL
wear
duration
in
general
was
11
years
(range:
4
months
to
53
years).
Fifty-eight
percent
of
patients
had
used
a
different
CL
type
prior
to
the
study.
2.5.
Subjective
performance
Median
VAS
outcome
for
the
entire
cohort
was
84
for
the
topic
of
comfort
(range:
14100),
76
for
visual
quality
(range:
4100),
86
for
lens
handling
(range:
15100),
and
85
for
overall
satisfaction
(range:
7100).
The
outcome
of
the
patient
questionnaire
for
all
patient
subgroups
is
summarized
in
Table
5.
The
three
clinical
indication
groups
did
not
differ
signicantly
with
respect
to
comfort
(P
=
0.16),
visual
quality
(P
=
0.14),
lens
handling
(P
=
0.15),
or
overall
satisfaction
(P
=
0.43;
Kruskal-Wallis
test).
Scleral
lens
users
did
not
differ
signicantly
from
soft
lens
users
with
respect
to
comfort
(P
=
0.29),
lens
handling
(P
=
0.21),
or
overall
satisfaction
(P
=
0.21,
Kruskal-Wallis
test).
However,
with
respect
to
subjective
visual
quality,
scleral
lens
users
differed
signicantly
from
soft
lens
users
(median
VAS
scores
were
77.5
and
75,
respectively;
P
=
0.009,
Kruskal-Wallis
test).
Five
percent
of
patients
scored
<50
in
the
comfort
topic;
3
used
scleral
lenses,
6
used
soft
lenses,
2
used
corneal
lenses,
2
used
iris
lenses,
and
1
used
a
lter
lens.
Fifteen
percent
of
patients
scored
<50
for
visual
quality;
14
used
scleral
lenses,
18
used
soft
lenses,
2
used
lter
lenses,
2
used
iris
lenses,
2
used
corneal
lenses,
and
1
used
a
tinted
soft
keratoconus
lens.
Five
percent
of
patients
scored
<50
in
for
lens
handling;
9
used
scleral
lenses,
and
1
used
a
tinted
soft
keratoconus
lens.
Lastly,
5%
of
patients
scored
<50
for
overall
satisfaction;
5
used
scleral
lenses,
6
used
soft
lenses,
and
2
used
iris
lenses.
2.6.
Effectiveness
of
medical
CL
tting
We
dened
good
performance
of
medical
CL
tting
as
an
overall
satisfaction
VAS
score
70
(out
of
100);
this
criterion
was
achieved
in
81%
of
patients.
Moreover,
90%
of
patients
reported
an
overall
satisfaction
score
60.
Importantly,
33%
of
patients
reported
an
overall
satisfaction
score
90.
3.
Discussion
The
primary
goal
of
this
study
was
to
evaluate
the
objective
and
subjective
performance
of
various
contact
lens
types
that
were
tted
based
on
a
lens
selection
algorithm
and
were
used
for
a
broad
range
of
clinical
indications.
Our
results
show
that
similar
outcomes
can
be
achieved
with
both
soft
lenses
and
scleral
lenses
when
tting
medical
contact
lenses.
Importantly,
subjective
comfort,
handling,
and
overall
satisfaction
were
similar
between
scleral
lens
users
and
soft
lens
users.
In
addition
to
underscoring
the
clinical
value
of
scleral
lenses,
our
results
also
highlight
the
need
for
practitioners
to
be
familiar
with
a
wide
range
of
lens
types
and
tailored
lens
selection.
A
large
number
of
studies
have
been
published
recently
regarding
the
indications
forand
the
application
ofmedical
CLs.
In
our
study,
the
most
common
indications
were
keratoconus,
dry
eye
disease,
and
keratoplasty;
moreover,
the
most
commonly
used
lens
types
were
scleral
lenses
and
soft
lenses
(including
conventional
soft
lenses
or
silicone
hydrogel
lenses).
The
objective
performance
of
scleral
lenses
in
our
study
cohort
is
consistent
with
previous
reports
by
our
group
[15,25,26]
and
others
[21,22].
Specically,
we
observed
high
outcome
with
respect
to
median
visual
acuity.
The
improvement
in
CL
CDVA
compared
to
spectacle
CDVA
was
the
most
pronounced
in
the
patient
subgroups
with
optical
indications
(i.e.,
the
keratoconus
and
keratoplasty
sub-
groups).
This
nding
supports
the
putative
optical
benet
of
CLs
and
is
consistent
with
other
studies
that
report
on
the
use
of
lenses
(including
scleral
lenses)
for
medical
indications
with
irregular
astigmatism
[11,21,22].
With
respect
to
therapeutic
lenses,
CL
CDVA
improved
as
well,
even
though
the
primary
objective
of
the
lenses
was
to
protect
or
promote
healing
of
the
compromised
cornea
[6].
The
optical
advantage
of
lenses
(including
scleral
lenses)
in
dry
eye
disease
due
to
compensation
of
optical
disturbances
that
arise
from
tear
instability,
punctate
epithelial
erosions,
and/or
corneal
scars
have
been
described
previously
[28,34,35].
Thus,
scleral
lenses
may
be
preferred
when
soft
lenses
fail,
and
scleral
lenses
may
even
surpass
soft
lenses
in
terms
of
hydrating
the
cornea,
protecting
the
cornea,
and/or
correcting
an
irregular
corneal
surface
[28,29].
Subjective
lens
performance
has
also
been
reported
previously.
Interestingly,
although
scleral
lenses
are
often
considered
to
be
cumbersome
to
handle,
our
study
cohort
reported
remarkably
high
overall
satisfaction,
regardless
of
lens
type.
Studies
of
CL
performance
in
which
different
lens
types
were
evaluated
simultaneously
in
a
clinical
setting
and
with
various
indications
have
not
been
reported
previously.
This
paucity
of
comprehensive
studies
prevents
a
comparison
of
either
objective
or
subjective
outcomes,
as
study
design,
patient
selection,
and
the
types
of
Table
4
Wearing
time
per
day
and
per
week.
Indication
or
lens
group
No.
of
eyes
daily
wear,
n
(%)
Median
wearing
time
per
day,
hours
(range)
Median
wearing
time
per
week,
days
(range)
Total
group
216
(77)
15
(518)
7
(17)
Keratoconus
71
(100)
15
(518)
7
(47)
Dry
eye
disease
29
(44)
16
(616)
7
(27)
Keratoplasty
54
(98)
15
(618)
7
(27)
Scleral
148
(100)
15
(518)
7
(27)
Soft
34
(34)
16
(717)
7
(47)
6
E.-S.
Visser
et
al.
/
Contact
Lens
&
Anterior
Eye
xxx
(2015)
xxxxxx
G
Model
CLAE
877
No.
of
Pages
9
Please
cite
this
article
in
press
as:
E.-S.
Visser,
et
al.,
Objective
and
subjective
evaluation
of
the
performance
of
medical
contact
lenses
tted
using
a
contact
lens
selection
algorithm,
Contact
Lens
&
Anterior
Eye
(2016),
http://dx.doi.org/10.1016/j.clae.2016.02.006
lenses
vary
widely.
Moreover,
the
indications
for
CLs
are
continuously
changing
due
to
developments
in
ophthalmology
[1].
Thus,
our
study
is
the
rst
to
provide
an
overarching
perspective,
and
our
lens
tting
algorithm
can
support
the
practitioner
in
selecting
the
most
appropriate
lens
type.
Our
study
has
several
notable
strengths.
First,
the
CL
practi-
tioners
in
this
study
participate
in
continuing
education,
with
an
emphasis
on
the
specic
skills
needed
to
advise
patients
in
a
tertiary
academic
clinical
setting.
Thus,
our
standardized
protocols
for
lens
selection,
lens
tting,
and
patient
instruction
are
the
result
of
many
years
of
experience
with
a
wide
range
of
CLs.
Furthermore,
all
of
the
major
steps
and
decisions
in
the
lens
selection
algorithm
are
based
on
peer-reviewed
literature.
In
addition,
it
is
important
to
t
CLs
individually
when
applying
bandage
CLs
to
complicated
eyes
[10,27],
which
is
reected
in
our
ow
chart
for
soft
lenses
and
silicone
hydrogel
lenses.
Thus,
the
appropriate
material,
param-
eters
[10],
modulus
[31],
and
replacement
strategy
are
all
essential
for
achieving
an
optimal
lens
t.
Importantly,
our
contact
lens
service
is
not
afliated
with
any
CL
manufacturer,
and
health
insurance
companies
reimburse
patients
for
CLs
prescribed
due
to
medical
indications.
Therefore,
lens
selection
was
not
guided
by
any
factors
other
than
the
individual
patients
needs
and
preferences.
Another
strength
of
this
study
was
our
random
selection
of
unilateral
eyes;
this
step
was
important,
given
the
high
degree
of
correlation
between
eyes
with
respect
to
lens
perfor-
mance.
Lastly,
subjective
performance
was
analyzed
solely
in
the
eye
under
study,
thus
further
avoiding
any
possible
undue
effects
due
to
the
performance
of
the
other
eye.
This
study
also
had
some
considerations
that
merit
mention,
the
most
important
of
which
is
patient
selection.
Our
contact
lens
service
is
in
a
tertiary
academic
center,
and
this
may
have
resulted
in
a
disproportionate
selection
of
more
severe
clinical
indications.
Because
of
its
excellent
cornea
unit,
our
ophthalmology
depart-
ment
has
a
relatively
large
population
of
patients
with
severe
dry
eye
andat
the
other
end
of
the
clinical
spectruma
relatively
large
proportion
of
post-graft
and
keratoconus
patients.
Thus,
our
clinic
is
an
interregional
referral
center
for
patients
with
keratoconus,
and
the
most
severe
cases
are
referred
to
our
contact
lens
service
for
evaluation
andif
neededrevision
of
their
current
CLs.
The
stage
of
the
disease
limited
the
available
lens
types
to
more
advanced
solutions;
thus,
a
relatively
higher
proportion
of
scleral
lenses
were
prescribed,
whereas
other
lens
types
(for
example,
RGP
corneal
lenses)
were
underreported.
Wu
et
al.
[24]
illustrated
this
phenomenon
by
reporting
that
RGP
corneal
lenses
do
not
ensure
improved
quality
of
life
for
patients
with
severe
keratoconus;
thus,
Wu
et
al.
stressed
the
importance
of
prescribing
the
appropriate
CL
type
for
each
grade
of
keratoconus.
Moreover,
patients
may
require
retting
as
their
disease
stages
change
[6],
and
the
optimal
CL
type
for
an
irregular
cornea
should
not
be
determined
solely
by
the
degree
of
irregularity.
Secondary
features
such
as
tear
lm
deciency
and
elevated
corneal
scars
can
also
play
an
important
role,
as
summarized
in
our
lens
selection
algorithm.
Interestingly,
we
found
that
58%
of
patients
previously
wore
different
lenses,
and
the
new
lens
type
yielded
a
high
level
of
overall
satisfaction.
This
result
suggests
that
the
majority
of
patients
wore
lenses
that
were
not
optimally
tting
prior
to
changing
their
lens
type.
This
suboptimal
tting
might
have
been
due
to
a
change
in
the
clinical
situation
(for
example,
the
progression
of
pathology,
additional
complicating
factors,
and/or
postsurgical
factors)
or
after
being
referred
to
our
clinic
for
poor
CL
performance.
Expanding
this
prospective
study
to
include
a
more
general
population
will
likely
reveal
important
information
regarding
various
CL
types
in
patients
in
earlier
stages
of
disease.
A
limitation
of
our
study
was
the
fact
that
the
cross-sectional
observational
design
did
not
allow
us
to
study
complications
associated
with
the
lenses.
Thus,
we
were
unable
to
evaluate
the
safety,
durability,
or
refractive
stability
of
the
lenses.
Interestingly,
however,
four
of
the
281
patients
in
our
study
cohort
needed
(relatively
minor)
revision
in
their
lenses
(all
four
of
which
were
scleral
lenses);
these
revisions
were
based
on
either
suboptimal
tting
or
altered
corneal
refraction.
This
nding
is
consistent
with
our
previous
nding
that
updating
scleral
lenses
with
relatively
Table
5
Subjective
outcomes
measured
using
a
VAS
questionnaire
with
scores
ranging
from
0
to
100 .
Indication
or
lens
group
No.
of
eyes,
n
(%)
Comfort
Visual
Quality
Lens
Handling
Overall
Satisfaction
Total
group
281
(100)
84
(14100)
N/A
N/A
85
(7100 )
Eyes
CDVA
1/300
a,b
259
(92)
N/A
76
(4100 )
N/A
N/A
Eyes
daily
wear
216
(77)
N/A
N/A
86
(15100)
N/A
Keratoconus
71
(100)
85
(2497)
N/A
N/A
86
(3498)
Eyes
CDVA
1/300
a
71
(100)
N/A
74
(2797)
N/A
N/A
Eyes
daily
wear
71
(100)
N/A
N/A
94
(3479)
N/A
Dry
eye
disease
66
(100)
78
(14100)
N/A
N/A
85
(28100)
Eyes
CDVA
1/300
a
64
(97)
N/A
75
(15100)
N/A
N/A
Eyes
daily
wear
29
(44)
N/A
N/A
85
(15100)
N/A
Keratoplasty:
55
(100)
84
(1497)
N/A
N/A
85
(1597)
Eyes
CDVA
1/300
a
55
(100)
N/A
84
(1496)
N/A
N/A
Eyes
daily
wear
54
(98)
N/A
N/A
85
(4496)
N/A
Scleral
lenses
148
(100)
84
(14100)
N/A
N/A
85
(15100)
Eyes
CDVA
1/300
a
148
(100)
N/A
77.5
(14100)
N/A
N/A
Eyes
daily
wear
148
(100)
N/A
N/A
86
(15100)
N/A
Soft
lenses
99
(100)
84
(1497)
N/A
N/A
85
(2698)
Eyes
CDVA
1/300
a,c
85
(86)
N/A
75
(497)
N/A
N/A
Eyes
daily
wear
34
(34)
N/A
N/A
91
(5597)
N/A
CDVA
=
corrected
distance
visual
acuity;
VAS
=
visual
analogue
scale;
VAS
outcomes
are
presented
as
the
median
(range);
N/A
=
not
applicable.
a
Distinguish
hand
motion.
b
4
patients
did
not
complete
this
question.
c
3
patients
did
not
complete
this
question.
E.-S.
Visser
et
al.
/
Contact
Lens
&
Anterior
Eye
xxx
(2015)
xxxxxx
7
G
Model
CLAE
877
No.
of
Pages
9
Please
cite
this
article
in
press
as:
E.-S.
Visser,
et
al.,
Objective
and
subjective
evaluation
of
the
performance
of
medical
contact
lenses
tted
using
a
contact
lens
selection
algorithm,
Contact
Lens
&
Anterior
Eye
(2016),
http://dx.doi.org/10.1016/j.clae.2016.02.006
minor
changes
every
1.5 2
years
is
common
practice
and
is
recommended
in
order
to
ensure
the
lens
materials
quality
and
oxygen
permeability
[26].
A
detailed
analysis
of
these
four
cases
did
not
provide
additional
insight
(data
not
shown).
In
their
recent
review
of
scleral
lenses,
Van
der
Worp
et
al.
[21]
concluded
that
adverse
events
are
rare
in
these
modalities.
In
addition,
other
studies
found
that
the
therapeutic
use
of
CLs
does
not
appear
to
affect
the
incidence
of
CL-related
complications
[36,9].
The
availability
of
silicone
hydrogel
materials
with
high
oxygen
permeability
has
opened
new
opportunities
for
patients
with
hypoxia-related
corneal
complications.
Indeed,
several
studies
reported
that
silicone
hydrogels
are
both
safe
and
efcacious
when
worn
continuously
for
therapeutic
purposes
[3,7,8].
Nevertheless,
it
is
obvious
that
the
wearing
of
CLs
involves
some
risk,
and
care
should
be
exercised
when
tting
a
compromised
eye.
Patients
must
be
educated
regarding
proper
lens
care
and
to
identify
signs
of
potential
complications
before
they
begin
using
medical
CLs.
The
high
subjective
performance
of
all
CL
types
was
reected
by
the
fact
that
patients
reported
wearing
their
CLs
many
hours
per
day
and
many
days
per