Clinical Ophthalmology

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ORIGINAL RESEARCH

Application of Second-Generation Swept-Source
Anterior Segment-OCT in the Measurement of
Marginal Reﬂex Distance-1 (MRD-1)
This article was published in the following Dove Press journal:
Clinical Ophthalmology

Kosuke Ogasawara
Medical Corporation, Ogasawara Eye
Clinic, Morioka Iwate 020-0114, Japan

Purpose: To measure marginal reﬂex distance-1 (MRD-1) values in normal subjects andpatients with blepharoptosis using second-generation swept-source anterior segment opticalcoherence tomography (AS-OCT) and to evaluate the usefulness of this measurement
method.
Materials and Methods: MRD-1 values were measured using AS-OCT in 80 eyes of 40
normal subjects (16 men and 24 women) aged 20–59 years with no neurological or endocrinological disorders, and the measured values were compared between four age groups comprising
20 eyes of 10 subjects each in their 20s, 30s, 40s, and 50s. The Volk Eye Check system wassimultaneously used to measure MRD-1 in 40 eyes of 20 normal subjects, and the measured
values were compared with those obtained using AS-OCT. In 21 eyes of consecutive 13
involutional blepharoptosis patients (48–84 years of age, mean 70.2 years), MRD-1 values
were measured using AS-OCT preoperatively and 3 months after surgery to examine the rates
of successful measurements as well as preoperative and postoperative results.
Results: The mean MRD-1 value using AS-OCT in 80 eyes of 40 normal subjects was 3.70 ±0.10 mm, whereas the values in 20 eyes of 10 subjects each from the four different age groups
were 4.01 ± 0.54 mm, 3.88 ± 0.60 mm, 3.96 ± 0.77 mm, and 2.94 ± 0.79 mm for subjects in their
20s, 30s, 40s, and 50s, respectively; signiﬁcant differences were observed between the 50s groupand other groups (p<0.01). The mean MRD-1 values using AS-OCT and the Volk Eye Checksystem in 40 eyes of 20 normal subjects were 3.68 ± 0.70 mm and 3.71 ± 0.84 mm, respectively,
with no signiﬁcant differences (p:0.87). The mean preoperative and postoperative MRD-1 values
in patients with involutional blepharoptosis were 0.29 ± 0.70 mm and 3.24 ± 0.92 mm,
respectively; the rate of successful MRD-1 measurements using AS-OCT was 100% among
trial subjects.
Conclusion: MRD-1 measurement using AS-OCT is a simple and reproducible method thatallows the direct comparison of numerical values in normal subjects as well as in patientswith blepharoptosis.
Keywords: blepharoptosis, MRD1, swept-source anterior segment-OCT

Introduction
Correspondence: Kosuke Ogasawara
Ogasawara Eye Clinic, 3-10-12,
Takamatsu, Morioka Iwate 020-0114,
Japan
Tel +81 19 662 3223
Fax +81 19 662 7331
Email oga-koke@diamond.broba.cc
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http://doi.org/10.2147/OPTH.S246731

With increasing age of the population, more patients are developing blepharoptosis,
thus increasing the need for its surgical treatment each year. Blepharoptosis causes
aesthetic issues and visual function problems, especially narrowed visual ﬁeld.1–5
International guidelines on the surgical treatment of blepharoptosis including
preoperative evaluation and selection of the surgical procedure have not been
established. Nevertheless, it is important to accurately measure the severity ofClinical Ophthalmology 2020:14 635–642

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Ogasawara

blepharoptosis before surgery. According to the recent
AAO opinion,4 blepharoptosis surgery is functionally indicated when marginal reﬂex distance 1 (MRD-1) is ≤2 mm.
Common methods to measure MRD-1 include the corneal
reﬂex-based measurement using a ruler (clinical method)6
and calculation using digital photographs and image
J software program (http://rsbweb.nih.gov/ij; digital
method).7 Recently, the Volk Eye Check system8 andanalogous methods9,10 have also been reported. In thisstudy, we used the second-generation swept-source anterior segment optical coherence tomography (AS-OCT)(CASIA2, Tomey Corporation, Nagoya, Japan) to measure
MRD-1 values in normal subjects and preoperative andpostoperative MRD-1 values in patients with blepharoptosis to assess its usefulness.

A

B

Materials and Methods
This study included adults with blepharoptosis or normal
eyelid position. Written informed consent was obtained
from all the subjects. The study was conducted as per thetenets of the Declaration of Helsinki and with the approvalof the medical corporation of Ogasawara Eye Clinic’s
ethical review board. Patients whose images and/or measurements appear in this publication provided additional
written consent for publication of their photographs.
MRD-1 values were measured using AS-OCT in 80
eyes of 40 normal subjects (16 men and 24 women) aged
20–59 years who had no systemic diseases such as neurological and endocrinological disorders (Figure 1A).
A snapshot taken during the measurement is shown in
Figure 1B. MRD-1 values were measured as follows: (1)Images were separately taken for the left and right eyes incataract preoperative measurement mode. Each subject
placed his/her face on the chin support and ﬁxed his/hereyes on a front orange ﬁxation lamp with both eyes open
naturally. (2) For analysis of MRD-1, an orthoptist clicked
the front monitor and ﬁxed the corneal reﬂex before
adjusting the yellow line to 90°. (3) MRD-1 was automatically measured when the memory was placed on the
superior palpebral margin and corneal apex. The measurements can be performed in a bright room. A typical example is shown in Figure 2. For patients whose superior
palpebral margin was lower than the pupil center, theeyelid was elevated to conﬁrm the pupil center and thenreturned to its original position before MRD-1 was measured (Figure 3).
The MRD-1 values measured using AS-OCT in normal
subjects were compared to detect any signiﬁcant difference636

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Figure 1 MRD-1 measurement scene using AS-OCT (A). A snapshot taken during
the MRD-1 measurement screen using AS-OCT (B).

between the four age groups comprising 20 eyes of 10
subjects each in their 20s, 30s, 40s, and 50s.
For comparison, the Volk Eye Check system8 wassimultaneously used to measure MRD-1 in 40 eyes of 20
normal subjects aged 20–59 years of age, mean 39.2 years.
As a prospective study, preoperative and postoperative
MRD-1 values were measured using AS-OCT in 21 eyesof consecutive 13 patients with involutional blepharoptosis(48–84 years of age, mean 68.6 years) to examine the rates
of successful measurements, reproducibility, and values
measured before and 3 months after surgery. The basic
surgical procedure was a modiﬁed transconjunctival tucking method that was reported by us.11
In this study, t-test and analysis of variance(Bonferroni’s method) were used to detect signiﬁcantdifferences.

Results
In 80 eyes of 40 normal subjects, the mean of MRD-1
values measured using AS-OCT was 3.70 ± 0.10 mm. In

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right eyeleft eyeAB

3.59mm

MRD-1

3.45mmFigure 2 A photograph of eyelids of a normal subject (A) and AS-OCT ﬁndings (B) A 26-year-old woman; MRD-1, right: 3.59 mm, left: 3.45 mm.

20 eyes of 10 subjects each from the four different age
groups, the mean MRD-1 values were 4.01 ± 0.54 mm,
3.88 ± 0.60 mm, 3.96 ± 0.77 mm, and 2.94 ± 0.79 mm for
subjects in their 20s, 30s, 40s, and 50s, respectively; signiﬁcant differences were observed between the 50s groupand other groups (Figure 4). The rate of successful measurements was 100%, and the measurements were reproducible. Successful means MRD-1 was able to bemeasured deﬁnitely in trial subjects and get acceptabledata.
The mean of MRD-1 values measured using AS-OCT and
Volk Eye Check system in 40 normal eyes of 20 subjects were3.68 ± 0.70 mm and 3.71 ± 0.84 mm, respectively, with nosigniﬁcant differences between the two methods (Figure 5).
The rate of successful measurements using AS-OCT was

Clinical Ophthalmology 2020:14

100%, whereas that using the Volk Eye Check system,8 theresult was 90%.
In patients with involutional blepharoptosis, MRD-1
values could be measured using AS-OCT for all cases,
including severe ones. The mean MRD-1 values measured
using AS-OCT before and 3 months after blepharoptosis
surgery were 0.29 ± 0.70 mm and 3.24 ± 0.92 mm, respectively, demonstrating signiﬁcant improvements (Figure 6).
Photographs taken before and 3 months after surgery andfor MRD-1 measurement for the representative patient are
in shown Figures 3 and 7, respectively.

Discussion
CASIA2 is an excellent instrument for AS-OCT, offering a variety of functions.12,13 These include cataract

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right eyeleft eyeA

B

C

0.23mm

MRD-1

0.58mmFigure 3 Photographs of eyelids of a patient with severe blepharoptosis (A), those being elevated to identify the pupil center (B), and those returned to the original positionand subjected to MRD-1 measurement (C). A 84-year-old man; MRD-1, right: −0.23 mm, left: −0.58 mm.

preoperative examination, gonioscopic analysis, andobservation of the ﬁltration bleb after glaucoma surgery, analysis of sagittal images of upper eyelid14 as

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well as corneal shape. In this study, we used AS-OCT
functions to measure MRD-1 values in normal subjects
and preoperative and postoperative MRD-1 values inClinical Ophthalmology 2020:14

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6.0

5

5.0

4

4.0

3

3.0
(MRD1)
2.0

2(MRD1)(mm) 1

1.0

0
0.0
20s

30s
(Age)

40s

50s
p<0.01Figure 4 MRD-1 measurement data from 20 eyes of 10 normal subjects in their20s–50s. Signiﬁcant differences were observed between the 50s group and othergroups by analysis of variance (Bonferroni’s method). F (3,76)=10.60, p<0.01.

5.0

4.0

3.0
(MRD1) 2.0
(mm)
1.0

0.0
AS-OCT

Eye Check System

Figure 5 Results of MRD-1 measurement using AS-OCT and Volk Eye Checksystem in normal subjects. AS-OCT mean: 3.68 ± 0.70 mm, Volk Eye Check systemmean: 3.71 ± 0.84 mm. No signiﬁcant differences between the two methods wereobserved.

patients with blepharoptosis to examine the usefulnessof AS-OCT.
This study revealed that MRD-1 could be measured
using AS-OCT in a simple manner, measured MRD-1
values could be directly compared as numerical values,and AS-OCT could be used to measure MRD-1 values innormal individuals as well as preoperative MRD-1 values
in patients with severe blepharoptosis. In addition, because
the reproducibility of measured values was high, it appears
that AS-OCT is a clinically signiﬁcant MRD-1 measurement method.
Compared with the AS-OCT method used in this study,
previously reported methods for MRD-1 measurement
have some drawbacks. The disadvantages of the clinical

Clinical Ophthalmology 2020:14-1
pre-ope MRD-1

post-ope MRD-1

Figure 6 Preoperative (pre-ope) and postoperative (post-ope) MRD-1 measurements in patients included in this study. The mean MRD-1 values of pre-ope and 3
months post-ope were 0.29 ± 0.70 mm and 3.24 ± 0.92 mm, respectively.

method include measurement errors as large as 0.5 mm6and a complicated process required for MRD-1 analysis,
although ImageJ is probably the most popular image analysis software program. The ORBSCAN2 topography system is used to improve the accuracy of values determinedwith the ImageJ program;15 however, this method is associated with several biases and has a disadvantage of indirectly measuring MRD-1 values. Choi et al9 compared
MRD-1 values obtained from ImageJ analysis of photographs taken with four different cameras and reported
MRD-1 errors varying approximately 0.5–0.7 mm depending on the differences in cameras used and positional andsize differences of ﬂashbulbs used.
In this study, we compared MRD-1 values that were
measured using AS-OCT and those measured using the
Volk Eye Check system.8 The Volk Eye Check System isa modiﬁed smartphone intended to collapse the space
between convenience of clinical and the precision of digital
measurements. This device is outﬁtted with image processing software that automatically measures parameters suchas MRD-1 in real-time using photographs taken by integrated camera. No signiﬁcant differences between the two
methods were noted in normal subjects (Figure 5).
However, in patients with blepharoptosis, MRD-1 could
be measured using the Volk Eye Check system only for≤50% of moderate to severe cases, and we could not compare the AS-OCT and Volk Eye Check system results in thispopulation. Sinha et al16 compared the values measured
using the clinical method, digital method, and Volk Eye
Check system. Similarly to our results, they found no signiﬁcant differences among the three groups in normal eyes.
In patients with blepharoptosis, they found that the Volksubmit your manuscript | www.dovepress.com

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right eyeleft eye

A

B

2.70

MRD-1

3.21

Figure 7 A photograph taken 3 months after surgery for severe blepharoptosis (A) and MRD-1 measured using AS-OCT (B) A 84-year-old man:MRD-1, right: 2.70 mm,
left: 3.21 mm. Before surgery photographs are shown in Figure 3.

Eye Check system overestimated the amount of blepharoptosis and the rate of successful measurements was approximately 66%. These and our data indicate advantage andsuperiority of AS-OCT compared to the Volk Eye Check
System. Many Japanese individuals have thick eyelids thatare shallow in depth and double eyelids are relatively minority. These characteristics may explain why software analysis of photographs is difﬁcult (see a representative case in
Figure 8). In AS-OCT measurement, there were concernsthat the instrument might interfere with MRD-1 because itis placed right in front of the eyes. Our results indicate that
this caused negligible errors, if any.
The AS-OCT method allows simple MRD-1 measurement even in moderate and severe blepharoptosis patientswith a stable measurable rate of 100%. In addition, this640

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method may be useful to accurately and objectively assessthe degree of recovery and postoperative course following
blepharoptosis surgery. Furthermore, this method may be
useful to identify unilateral blepharoptosis and compare theamounts of blepharoptosis between the left and right eyes.

Conclusions
MRD-1 measurement using AS-OCT is a simple andreproducible method that allows the direct comparison ofnumerical values. AS-OCT can be used to measure MRD1 values for preoperative and postoperative values inpatients with blepharoptosis. This measurement method
might enable accurate and objective assessment of thedegree of recovery and postoperative course following
blepharoptosis surgery.

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right eyeleft eye

A

B

C

4.14

MRD-1

3.86

Figure 8 A photographs of eyelids of a 75-year-old male patient with severe blepharoptosis (A) and postoperative three months after surgery (B, C). Measuring MRD-1
values by AS-OCT (C) are 4.14 mm in right eye and 3.86 mm in left eye. Preoperative MRD-1, right eye:-0.81 mm, left eye:-1.19 mm.

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Disclosure
The author reports no conﬂicts of interest in this work.

References
1. Battu VK, Meyer DR, Wobig JL. Improvement in subjective visualfunction and quality of life outcome measures after blepharoptosis
surgery. Am J Ophthalmol. 1996;121:677–686. doi:10.1016/S00029394(14)70634-8
2. Federici TJ, Meyer DR, Lininger LL. Correlation of the vision-related
functional impairment associated with blepharoptosis and the impactof blepharoptosis surgery. Ophthalmology. 1999;106:1705–1712.
doi:10.1016/S0161-6420(99)90354-8
3. Ho SF, Morawski A, Sampath R, et al. Modiﬁed visual ﬁeld test for
ptosis surgery (Leicester Peripheral Field Test). Eye. 2011;25:365–369.
doi:10.1038/eye.2010.210
4. Cahill KV, Bradley EA, Meyer DR, et al. Functional indications forupper eyelid ptosis and blepharoplasty surgery: a report by theAmericanAcademyofOphthalmology.
Ophthalmology.
2011;118:2510–2517. doi:10.1016/j.ophtha.2011.09.029
5. Pemberton JD, Salter M, Fay A, et al. Investigation of goldmann
perimetry in evaluation of patients for upper eyelid blepharoplasty.
Orbit. 2018;37:48–52. doi:10.1080/01676830.2017.1353115
6. Boboridis K, Assi A, Indar A, et al. Repeatability and reproducibilityof upper eyelid measurements. Br J Ophthalmol. 2001;85:99–101.
doi:10.1136/bjo.85.1.99
7. Choi CJ, Lefebvre DR, Yoon MK. Validation of the facial assessment
by computer evaluation (FACE) program for software-aided eyelid
measurements. Orbit. 2016;35:117–120. doi:10.3109/01676830.2016.
1139595

Clinical Ophthalmology

8. Volk Eye check―ocular measurement device. Available from:https://volk.com/media/wysiwyg/pdf/ifu/IM-078/IM-078_English.
pdf. Accesed July 5, 2017.
9. Choi CJ, Chou JC, Lefebvre DR, et al. Margin reﬂex distance: differences based on camera and ﬂash positions. Ophthalmic Plast Reconstr
Surg. 2016;32:199–203. doi:10.1097/IOP.0000000000000456
10. Rüfer F, Schröder A, Erb C. White-to-white corneal diameter: normal
values in healthy humans obtained with the Orbscan II topography system.
Cornea. 2005;24:259–261. doi:10.1097/01.ico.0000148312.01805.53
11. Ogasawara K. Ptosis surgery with an improved method of shortening
the Müller’s muscle and the levator aponeurosis with transconjunctival threading. J Ophthalmic Surg. 2019;2:7–12.
12. Tomey Corporation. Fourier domain OCT CASIA2. Available from:http://tomey.de/images/product_ﬂyer/CASIA2_br_w.pdf. Accessed
November 21, 2017.
13. Xu BY, Mai DD, Penteado RC, et al. Reproducibility and agreementof anterior segment parameter measurements obtained using the
CASIA2 and spectralis OCT2 optical coherence tomography
devices. J Glaucoma. 2017;26(11):974–979. doi:10.1097/IJG.000000
0000000788
14. Zheng X, Goto T, Shiraishi A, et al. New method to analyze sagittal
images of upper eyelid obtained by anterior segment optical coherence tomography. Orbit. 2019;38(6):446–452. doi:10.1080/
01676830.2018.1563200
15. Rajyalakshmi R, Prakash WD, Ali MJ, et al. Periorbital biometricmeasurements using ImageJ software: standardisation of techniqueand assessment of intra- and interobserver variability. J Cutan Aesthet
Surg. 2017;10:130–135. doi:10.4103/JCAS.JCAS_61_17
16. Sinha KR, Yeganeh A, Goldberg RA, et al. Assessing the accuracy ofeyelid measurements utilizing the Volk eye check system and clinicalmeasurements. Ophthalmic Plast Reconstr Surg. 2018;34:346–350.
doi:10.1097/IOP.0000000000000991

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