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ORIGINAL ARTICLE
resbyopia, from the Greek words presbys meaning
“old man” and ops meaning to “see like,” is the in-
ability to comfortably focus on close objects due to
aging. This is the most common physiologic alteration of eye-
sight, affecting more than 1.2 billion individuals worldwide,
and leads to a major impact on productivity among healthy
adults.1 Presbyopia also significantly affects quality of life in
both developed and developing countries.2 Unlike ametropic
defects or refractive errors (myopia, hyperopia, and astigma-
tism), caused by genetic and envi ronmental conditions that
affect the shape of the eye, presbyopia does affect virtually
every individual older than 50 or 60 years due to the progres-
sive loss of the accommodation ability of the eye.
Current treatments for presbyopia are based on optical cor-
rections, but surgical refractive modifications are also possible.
Although near vision can be easily recovered by the use of read-
ing glasses, there is nonetheless a great demand for more perma-
nent solutions to avoid the use of corrective lenses. However,
available invasive surgical procedures have several limitations
and are not devoid of side effects.3 Pharmaceutical treatments
stimulating the contraction of ciliary muscles in the presence of
different miotics4-6 and nonsteroidal anti-inflammatory drugs7
have been recently described, suggesting the relevance of the
stimulation of the ciliary muscle to recover some of its function.
P
ABSTRACT
PURPOSE: To report short-term results of pulsed ciliary
muscle electrostimulation to improve near vision, likely
through restoring accommodation in patients with em-
metropic presbyopia.
METHODS: In a prospective non-randomized trial, 27
patients from 40 to 51 years old were treated and
13 age- and refraction-matched individuals served as
untreated controls. All patients had emmetropia and
needed near sphere add between +0.75 and +1.50
diopters. The protocol included four sessions (one every
2 weeks within a 2-month period) of bilateral pulsed (2
sec on; 6 sec off) micro-electrostimulation with 26 mA
for 8 minutes, using a commercially available medical
device. The uncorrected distance visual acuity (UDVA)
(logMAR) for each eye, uncorrected near (40 cm) visual
acuity in each eye (UNVA) and with both eyes (UNVA OU)
(logMAR), and reading speed (number of words read per
minute at 40 cm) were measured preoperatively and 2
weeks after each session. Overall satisfaction (0 to 4
scale) was assessed 2 weeks after the last session.
RESULTS: UDVA did not change and no adverse events
were noted in either group. Bilateral and monocular
UNVA and reading speed were stable in the control
group, whereas they continuously improved in the
treated group (Friedman, P < .00001). Post-hoc sig-
nificant differences were found for monocular and bin-
ocular UNVA after the second treatment and after the
first treatment considering words read per minute (P <
.001). One patient (3.7%) was not satisfied and 18 pa-
tients (66.7%) were very satisfied (score of 4). Average
satisfaction score was 3 (satisfied).
CONCLUSIONS: Ciliary muscle contraction to restore
accommodation was safe and improved the short-term
accommodative ability of patients with early emme-
tropic presbyopia.
[J Refract Surg. 2017;33(9):578-583.]
From Diagnostica Oftalmologica e Microchirurgia Oculare, Rome, Italy
(LG, FG, VC, TF, MG); Sooft Italia SpA, Rome, Italy (DR); Rio de Janeiro
Corneal Tomography and Biomechanics Study Group, Instituto Olhos Renato
Ambrósio, Rio de Janeiro, Brazil (RA, MQS, BL); and Federal University of São
Paulo, São Paulo, Brazil (RA, MQS, BL).
Submitted: January 22, 2017; Accepted: May 26, 2017
Dr. Rusciano is a full-time employee of Sooft Italia, the company that com-
mercializes the electrostimulation device in Italy. The remaining authors have
no financial or proprietary interest in the materials presented herein.
The authors thank Dr. Federica Iannella, psychologist (University “La
Sapienza,” Rome, Italy), Dr. Carlo Leoni, psychologist (University “La
Sapienza,” Rome, Italy), and Professor Massimo Biondi, Director of Psychiatric
Department (University “La Sapienza,” Rome, Italy), for their contributions
elaborating the results of the Minnesota Test, and Dr. Antony Bridgewood
(University of Catania, Italy) for English proofreading of the manuscript.
Correspondence: Luca Gualdi, MD, Diagnostica Oftalmologica e Microchirurgia
Oculare, Via F. Civinini 111, 00197 Rome, Italy. E-mail: luca@gualdi.it
doi:10.3928/1081597X-20170621-05
Ciliary Muscle Electrostimulation to Restore
Accommodation in Patients With Early
Presbyopia: Preliminary Results
Luca Gualdi, MD; Federica Gualdi, MD; Dario Rusciano, PhD; Renato Ambrósio, Jr., MD, PhD;
Marcella Q. Salomão, MD; Bernardo Lopes, MD; Veronica Cappello, MD; Tatiana Fintina, MD;
Massimo Gualdi, MD
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Journal of Refractive Surgery • Vol. 33, No. 9, 2017
Ciliary Muscle Electrostimulation to Restore Accommodation/Gualdi et al
An alternative approach could address the revitalization
of the accommodation system by stimulating the ciliary
muscle to increase its potency so that it can overcome the
higher resistance of the system (ciliary muscle and lens)
that has become stiffer due to aging.8 Pulsed electrostim-
ulation is known to work for atrophic muscles9,10 and
therefore might also be effective on the ciliary muscle.11
We describe a non-invasive and innovative method to
improve near vision, likely through restoring the accom-
modation mechanism through pulsed micro-electrostim-
ulation of the anterior segment of the eye to stimulate
ciliary muscle contraction to restore accommodation.
PATIENTS AND METHODS
The study was conducted in accordance with the te-
nets of the 1964 Declaration of Helsinki, revised in 2000.
All patients signed an informed consent according to the
policies of the Associazione Italiana Medici Oculisti. In
a prospective non-randomized trial, 27 patients from 40
to 51 years old were treated and 13 individuals matched
for age and refraction served as untreated controls. All
patients had emmetropia with an uncorrected distance
visual acuity (UDVA) of 20/20 (0.0 logMAR) or better
and needed near sphere add between +0.75 and +1.50
diopters (D). Manifest refraction in both groups did not
change UDVA with any spherical or cylindrical addi-
tion; all patients had visual acuity of 20/20 or better and
a spherical equivalent of ±0.25 D or less (as measured by
the autorefractometer). Based on these data, cycloplegic
refraction was performed only on 5 patients at random
(to avoid the discomfort caused by this procedure to the
rest of the patients), and the resulting spherical equiva-
lent was found to be not more than +0.375 D.
Exclusion criteria included any ocular pathology, in-
cluding demyelinating and vascular diseases that may
reduce blood perfusion of the ciliary body, and epilepsy.
Patients who had a pacemaker were also excluded be-
cause of possible electrical interactions. In addition, pa-
tients receiving specific treatments that could possibly
influence accommodation, such as antidepressant, anti-
spasmodic, antihistaminic, and diuretic drugs, were also
excluded. To exclude patients with obvious psychologi-
cal problems, all of those enrolled had to complete the
psychological Minnesota Test questionnaire (MMPI-2),
consisting of 567 questions to which a true or false an-
swer has to be given. The results were elaborated by the
Psychology Department of the University “La Sapienza”
in Rome, Italy. Enrolled patients were advised about the
possible advantages and limitations of the procedure.
The protocol, established after previous experience, in-
cluded four sessions of bilateral pulsed (2 sec on; 6 sec off)
micro-electrostimulation with 26 mA for 8 minutes, with
2-week intervals, using the Ocufit medical device (Sooft;
Montegiorgio, Italy) consisting of special lenses and a cali-
brated power supply to which the lenses have to be con-
nected (see below). Micro-electrostimulation treatments
were performed by the first author (LG) at the Diagnostica
Oftalmologica e Microchirurgia Oculare clinic in Rome,
Italy. Two drops of 0.4% oxybuprocaine were instilled
before treatment with the patient in the supine position.
A 20-mm polycarbonate scleral contact lens equipped
with four microelectrodes at the four cardinal points po-
sitioned 3.5 mm outside the limbal area corresponding to
the ciliary body region (Figure A and Video 1, available
in the online version of this article) was used. The micro-
electrodes were connected through four electric pins and
cables to the electrical generator (Figures AA-AC). The
lens was carefully applied onto the eye (Figure AD) to
avoid trauma to the ocular surface. The electrostimula-
tor (Sooft) generates biphasic compensated square waves
for a low voltage micro-electrostimulation of the ciliary
muscle. The amount of electrical current flowing from
the positive to the negative pole remained stable, and
any risk of thermal damage was prevented. During the
8 minutes of treatment, 60 cycles of electrostimulation
were given, with each cycle consisting of 2 seconds of
electrical impulse and 6 seconds of rest (Figure AE).
After each treatment, two drops of an antibiotic-steroid
were instilled in each treated eye to prevent postopera-
tive inflammation or infection. No other medications
were needed. Although both eyes could be treated si-
multaneously, treatments were generally performed in
one eye with immediate sequential treatment of the fel-
low eye. The ciliary muscle contraction to restore ac-
commodation didactic demonstration of the procedure
is available online (https://youtu.be/724pb1Kyp80).
Clinical examinations were performed 1 hour pri-
or to the ciliary muscle contraction to restore accom-
modation treatment and 2 weeks after each treatment
(just before starting the next one). Because the proto-
col included four sessions, the last examination was
approximately 2 weeks after the fourth treatment (or 2
months after enrollment). LogMAR UDVA for each eye,
logMAR uncorrected near (40 cm) visual acuity in each
eye (UNVA) and in both eyes (UNVA OU), and reading
speed (number of words read per minute at 40 cm) were
taken preoperatively and 2 weeks after each session.
UNVA was measured on standard MNREAD charts at a
fixed distance of 40 cm, under standard (500 lux) illu-
mination and no extra lighting. Reading speed was mea-
sured by two orthoptists, one holding a chronometer
and the other counting the words, under standard room
illumination on MNREAD charts at 40 cm distance.
Objective variations of the accommodation system
were measured (only in one eye randomly chosen from
7 patients) by ultrasound biomicroscopy (Optikon, Rome,
580 Copyright © SLACK Incorporated
Ciliary Muscle Electrostimulation to Restore Accommodation/Gualdi et al
Italy), which was recorded under standard illumination
with the patient in the supine position after the instilla-
tion of two drops of anesthetic (oxybuprocaine) 2 minutes
before the examination. Three good quality images were
recorded for far vision (with the eye focused on infinity,
with the lens in the relaxed position) and three for near vi-
sion (with the eye focused on a near point at 30 cm, with
the lens at the maximum accommodation and thickness).
Overall satisfaction (0 to 4 scale, where 0 is no
satisfaction and 4 is high satisfaction) was assessed
2 weeks after the last session, at the time of the last
clinical examination.
StatiStical analySiS
Statistical analyses were performed by different soft-
ware packages: MedCalc Statistical Software (version
16.8.4; MedCalc, Ostend, Belgium: https://www.medcalc.
org) and the R Core Team (version 3.3.1.2016; R Founda-
tion for Statistical Computing, Vienna, Austria: https://
www.R-project.org). The non-parametric Friedman test
was used for testing the differences between the several
time points for the same patients for each outcome vari-
able analyzed. If the null-hypothesis was rejected with
a P value of less than .001, pairwise post-hoc analysis
was conducted based on Conover’s method.12 Because
the Friedman test is for related samples, all cases had no
missing observations for the analyzed variables.
RESULTS
Among the 27 treated patients, 17 (63%) were wom-
en. The average patient age was 45.74 ± 3.35 years
(range: 40 to 51 years). The control group of 13 indi-
viduals had 7 women (53.84%) and the average age
was 45.8 ± 3.1 years (range: 40 to 49 years).
Three of the 27 treated patients (11.11%) reported a dry
eye sensation soon after treatment, which was completely
resolved in 48 hours by using artificial tears containing hy-
aluronic acid. No other side effects were observed.
Table 1, Tables A-B (available in the online version
of this article), and Figures 1-3 include the data values
and their graphic illustration of UNVA, UNVA OU)
and reading speed defined earlier. UNVA improved
after the second treatment compared to preoperative
values, whereas reading speed was significantly im-
proved soon after the first treatment. Considering the
UNVA for each eye, there was a continuous improve-
ment. UNVA OU was better than in separated eyes,
which shows the improvement due to binocularity.
An ultrasound biomicroscopy study was done on 7
eyes randomly chosen from 7 treated patients to obtain
a quantitative and objective measurement of the change
occurring during accommodation soon after electro-
stimulation training. The measurement was taken in the
supine position with both eyes open and one eye had
the ultrasound biomicroscopy immersion measurement
taken with the patient looking at distance and to the close
target. The lens curvature and thickness were recorded
at its maximum convexity, showing an average increase
of +0.07 mm (range: 4.10 to 4.17 mm) of the lens thick-
ness, a decrease of the anterior lens curvature of -0.24
mm (range: 6.96 to 6.72 mm), and a decrease of the poste-
rior lens curvature of -0.08 mm (range: 4.60 to 4.52 mm).
Figure 4 shows a representative picture of this analysis.
None of the clinical parameters were altered (P >
.10) in the control group at the time of their enroll-
ment, and all remained stable over the corresponding
time of observation.
A subjective questionnaire was given to treated pa-
tients to record their satisfaction 2 weeks after the end
of the fourth treatment cycle, at the time of the last
assessment. Most (96.3%) stated that they were satis-
fied and felt a real improvement in their visual abil-
ity (highly improved = 10, improved = 8, slightly im-
proved = 8, not improved = 1).
DISCUSSION
This is the first clinical report of the results of
pulsed ciliary muscle contraction to restore accommo-
dation. Although we have reported short-term results
(up to 2 months), our findings support ciliary muscle
contraction to restore accommodation as a promising
treatment for presbyopia.
TABLE 1
LogMAR UNVA (Smallest Character) Data Measured by
MNREAD Charts at 40 cm Distance
UNVA Minimum 25th Percentile Median 75th Percentile Maximum
Preop -0.1 0.025 0.12 0.23 0.36
T1 -0.12 0.01 0.1 0.2 0.31
T2 -0.2 0.025 0.1 0.18 0.29
T3 -0.19 0.02 0.09 0.16 0.34
T4 -0.2 0 0.08 0.12 0.24
UNVA = uncorrected near visual acuity; preop = preoperative
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Journal of Refractive Surgery • Vol. 33, No. 9, 2017
Ciliary Muscle Electrostimulation to Restore Accommodation/Gualdi et al
The complete pathophysiology of presbyopia remains
poorly understood. Donders (1864) proposed that presby-
opia is caused by a decrease in the force of contraction
of the ciliary muscle with age and Helmholtz (1855) sug-
gested that the lens becomes more difficult to deform with
age due to lenticular sclerosis.13 According to the latter
theory, accommodation occurs as a result of the elastic
properties of the lens and possibly the vitreous, which al-
low the lens to expand and increase its power when zonu-
lar tension is relieved during ciliary muscle contraction.14
As the lens changes with age, the ability to expand and in-
crease its refractive power is progressively lost. Possibly,
a combination of these two mechanisms determines the
evolution and natural course of presbyopia. Interestingly,
Helmholtz’s theory of sclerosis of the crystalline lens as
the cause of presbyopia was challenged by Schachar,15
who suggested that when the longitudinal muscle fibers
of the ciliary muscle contract during accommodation,
they place more tension on the equatorial zonules while
relaxing the anterior and posterior zonules. This force dis-
tribution causes an increase in the equatorial diameter of
the lens, decreasing the peripheral volume while increas-
ing the central volume. As the central volume increases,
so does the power of the lens. According to Schachar’s
theory, presbyopia occurs because of the increasing equa-
torial diameter of the aging lens. Once the lens diameter
reaches a critical size, usually during the fifth decade of
life, the ability of the ciliary muscle to provide resting ten-
sion on the zonules is significantly reduced.
Although there are several approaches to manage the
visual disability associated with presbyopia, most of the
currently available treatments are compensatory optical
tools rather than corrective, involving more pseudo-
accommodation rather than true accommodation. Meth-
ods used so far for the correction of presbyopia include
contact lenses and spectacles, whereas the surgical cor-
rection of presbyopia remains a challenge for refractive
surgeons.16 Pharmacological attempts to counteract pres-
byopia also exist. They are focused on relieving lens rigid-
ity (eg, eye drops containing lipoic acid17) or enhancing
iris and ciliary muscle contractility (with a combination
of one parasympathetic agent, one NSAID, two alpha-
agonists agents, and one anticholinesterase agent).6
Accommodation occurs by the contraction (forward
and inward movement) of the ciliary muscle and relax-
ation of the zonular fibers, resulting in lens thickening
and steepening with consequent increase in the conver-
gence refractive power of the eye.18 Therefore, age-related
changes in each component of the accommodative ap-
paratus (either separately or combined) have been impli-
cated in the pathophysiology of presbyopia, including
lens hardening19 and posterior restriction of the ciliary
Figure 1. Dot-plot with superimposed box plot of the logMAR uncorrected
near visual acuity (UNVA) (smallest character) measured by MNREAD
charts at 40 cm distance at the different time points, along with the
pairwise post-hoc significant differences. ***P < .001.
Figure 2. Dot-plot with superimposed box plot of the logMAR uncorrected
near visual acuity (smallest character) with both eyes (UNVA OU) measured
by MNREAD charts at 40 cm distance at the different time points, along
with the pairwise post-hoc significant differences. ***P < .001.
Figure 3. Dot-plot with superimposed box plot of the reading velocity mea-
sured as the number of words read per minute at the different time points,
along with the pairwise post-hoc significant differences. ***P < .001.
582 Copyright © SLACK Incorporated
Ciliary Muscle Electrostimulation to Restore Accommodation/Gualdi et al
muscle.20 Crystalline lens weight progressively increases
with aging due to the gradual loss of water content and
the increase of glycoproteins such as albumin and electro-
lytes such as calcium and potassium.21 Moreover, there
is an increment of disulfide bonding, oxidation of me-
thionine, and deamination and degradation of glutamine
and asparagine leading to protein backbone cleavage.
The consequence is lens stiffening with a progressive de-
crease of the refractive power during accommodation.22
Therefore, considering the ciliary muscle as the engine of
the accommodative process, and because its magnitude
of forward centrally and inward movement is reduced
with increasing age,23,24 an alternative approach for pres-
byopia might be to address its revitalization.
Our hypothesis is that ciliary muscle contraction to
restore accommodation addresses such an active part of
the accommodation system by working out the ciliary
muscle to increase its potency, so that it can overcome
the higher resistance of the system that has become stiffer
due to aging. This approach is already known to work for
atrophic muscles9,10 and might also work on the ciliary
muscle. If this hypothesis is correct, then the contraction
of the ciliary muscle is expected to stretch the tendinous
formation in direct contact with the sclerocorneal trabec-
ulate, thus increasing the distance between the lamellae
of the sclerocorneal angle. In this way, it could also re-
store the natural function of the trabeculate in aged pa-
tients, thus reducing their intraocular pressure.25,26 Ac-
cordingly, electrostimulation was found to be effective
in decreasing intraocular pressure in patients affected by
ocular hypertension and glaucoma.11,27
However, based on recent evidence,28,29 the question
remains as to how ciliary muscle contraction to restore
accommodation partially restores “true physiological
accommodation” differently from other more invasive
procedures, which create some form of “pseudoaccom-
modation” or other corneal or lenticular aberrations.
This may be the subject of further research, likely also
based on different evaluation methods.30
The data presented demonstrate that electrostimula-
tion is effective in improving near vision ability in pa-
tients with early presbyopic emmetropia, which is likely
related to restoring the accommodation process because
the data suggest that ciliary muscle contraction to re-
store accommodation enhances the ability of the ciliary
muscle to contract and thereby perform accommodation.
Electrostimulation works like training in physiotherapy,
so that the best results are expected for young presbyopic
patients (40 to 50 years), when the ciliary muscle starts
needing more strength to move a stiffer and bigger lens.
Also, there should be an age limit for the efficiency of
such treatment. Interestingly, because presbyopia is con-
sidered a preliminary stage prior to age-related cataract,31
in a continuum process described as “dysfunctional lens
syndrome,” ciliary muscle contraction to restore accom-
modation could be associated with other treatments that
aim to reverse the lens aging process, which leads to
presbyopia and is also associated with ocular hyperten-
sion and possibly cataract formation.
Because ciliary muscle contraction to restore accom-
modation is a passive exercise, the effect of electrostimu-
lation is expected to last for a limited time period and
then progressively regress. To maintain the benefit, it is
necessary to periodically repeat the treatment, which re-
quires developing customized programs based on the in-
dividual response related to the observed effect. Patient
Figure 4. Example of preoperative (left) and postoperative (right) ultrasound biomicroscopy scan taken under accommodation showing an increased
lens thickness (L) (+0.10 mm), a decreased anterior (Ra) and posterior (Rp) ray of curvature of the lens (-0.16 and -0.08 mm) resulting in improved
accommodative response after the micro-electrostimulation of the ciliary muscle treatment.
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Journal of Refractive Surgery • Vol. 33, No. 9, 2017
Ciliary Muscle Electrostimulation to Restore Accommodation/Gualdi et al
education is fundamental to ensure realistic expecta-
tions, but also challenging. Further studies are under way
in our clinic (and several others) to optimize the elec-
trostimulation parameters (time, voltage, and device) to
improve such results. Moreover, it is possible that novel
approaches may play a synergistic role in ciliary muscle
contraction to restore accommodation such as pharmaco-
logic treatments with lipoic acid17,32 or N-acetylcarnosine
eye drops33 that appear to work by restoring lens elastic-
ity and preventing age-related changes.
AUTHOR CONTRIBUTIONS
Study concept and design (LG, FG, RA, VC, MG); data collection
(LG, DR, TF); analysis and interpretation of data (LG, DR, RA, MQS,
BL, TF); writing the manuscript (LG, DR, RA); critical revision of the
manuscript (LG, FG, DR, RA, MQS, BL, VC, TF, MG); statistical ex-
pertise (RA, BL); administrative, technical, or material support (LG,
TF); supervision (LG, FG, VC, MG)
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Figure A. Illustration of the medical device for the electrostimulation of the ciliary muscle. (A) Bottom side of the
lens showing the four electrode contacts. (B) Upper side of the lens showing the four cables to be connected to the
power generator. (C) Positioning of the lenses on the ocular surface of a patient. (D) Power supply during a bilateral
simultaneous treatment in which two scleral contact lenses in polycarbonate are stabilized by two syringes creat-
ing a vacuum and connected by cables directly to the Ocufit (Sooft; Montegiorgio, Italy) electrostimulator medical
device. (E) Pulse trains are in the form of compensated biphasic square-waves. The graph illustrates treatment cycle
sequences consisting in pulsed repetitions of 2 seconds of electrical impulse followed by 6 seconds of rest.
TABLE A
Binocular UNVA (Smallest Character) Data Measured by
MNREAD Charts at 40 cm Distance
Time Minimum 25th Percentile Median 75th Percentile Maximum
Preop -0.2 0.0175 0.1 0.223 0.33
T1 -0.2 0.01 0.1 0.18 0.3
T2 -0.25 0.0025 0.05 0.11 0.23
T3 -0.2 0 0.02 0.1 0.31
T4 -0.2 -0.075 0.02 0.1 0.21
UNVA = uncorrected near visual acuity; preop = preoperative
TABLE B
No. of Words Read per Minute at 40 cm Distance
Time Minimum 25th Percentile Median 75th Percentile Maximum
Preop 76 116 142 161.25 261
T1 103 137.75 162 188.75 262
T2 106 152.75 176 212.75 269
T3 131 165.75 180 228 284
T4 140 178.5 203 217.75 284
preop = preoperative
