Unity VCS: A Comparison Study Evaluating Corneal Clarity and Thickness at Day 1 and Day 8 Post Op
Phase: NA
Conditions: Cataract
Sponsor: Metrolina Eye Associates, PLLC

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Unity VCS: A Comparison Study Evaluating Corneal Clarity and 
Thickness at Day 1 and Day 8 Post Op 
An investigator-initiated clinical trial 
1. TITLE PAGE 
 
Protocol Number:  
 
IM-25-02 
 
Amendment Number:  
Version 1.0 
 
IRB/ERC.  
 
 
Advarra IRB 
 
 
 
 
6100 Merriweather Drive, Suite 600 
 
 
 
 
Columbia, Maryland 21044 
 
Sponsor Name and Address: Ivan Mac, MD 
 
 
 
 
Metrolina Eye Associates 
 
 
 
 
4101 Campus Ridge Road, Suite 200 
 
 
 
 
Matthews, NC 28105 
 
 
 
 
 
(funding only; this is an investigator-initiated study 
 
 
 
 
IIT # 98711335) 
 
 
 
 
Alcon 
 
 
 
 
6201 South Freeway 
 
 
 
 
Fort Worth, TX 76134-2001, USA 
 
Test Articles:   
 
Unity VCS (with Unity handpiece and 4D motion) and 
Centurion Vision System (with Ozil handpiece and 
torsional motion) 
 
 
Investigator:   
 
Ivan Mac, MD 
 
 
 
 

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2. Table of Contents 
1. Title Page…………………………………………………………………………….. 1 
2. Table of Contents…………………………………………………………………….. 2 
3. Investigator Agreement………………………………………………………………..4 
4. Study Overview……………………………………………………………………….5 
5. Introduction……………………………………………………………………………6 
6. Objective(s)……………………………………………………………………………6 
7. Subjects………………………………………………………………………………..6 
7.1. Subject Population………………………………………………………………..6 
7.2. Inclusion Criteria…………………………………………………………………6 
7.3. Exclusion Criteria………………………………………………………………...7 
8. Study Details…………………………………………………………………………..7 
8.1. Study Design……………………………………………………………………...7 
8.2. Steps to Minimize Bias…………………………………………………………...8 
9. Study Procedure……………………………………………………………………….8 
9.1. Subject Enrollment and Informed Consent……………………………………….8 
9.2. Study Visits ………………………………………………………………………8 
9.3. Study Methodology……………………………………………………………….9 
9.4. Discontinued Subjects…………………………………………………………...11 
10. Analysis Plan…………………………………………………………………………11 
11. Sample Size…………………………………………………………………………..11 
12. Study Confidentiality/ Publication…………………………………………………...12 
13. Adverse Events.……………………………………………………………………...12 
14. Ethical Considerations……………………………………………………………….12 
15. References…………………………………………………………………………...13 
 
 
 
 
 
 
 

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3. Investigator Agreement 
I confirm that I have read and that I have understood the protocol named “Unity 
VCS: A Comparison Study Evaluating Corneal Clarity and Thickness at Day 1 and 
Day 8 Post Op and understand the study product’s operation. I agree to conduct this 
study in strict accordance with the protocol and will prioritize the rights, safety, 
privacy, and well-being of study subjects in accordance with the following. 
• The ethical principles covered under the Declaration of Helsinki. 
• Any applicable laws and regulations, including those that cover data privacy. 
• Requirements for reporting any serious adverse events. 
 
Signature of Investigator: _____________________________________________ 
 
Investigator’s Name (Print): ___________________________________________ 
 
Date: ______________________________________________________________ 
 
Name of Facility: ____________________________________________________ 
 
Facility Address: ____________________________________________________ 
 
                                           
 
 
 
 
 

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4. General Study Information 
 
Objective: 
To investigate the central corneal thickness and the corneal clarity 
when preforming phacoemulsification at a lower IOP setting using 
Unity VCS compared to a higher IOP setting with the Centurion 
Vision System with Ozil. 
 
Test Article: 
Unity VCS (with Unity handpiece and 4D motion)  
 
Control Article: 
Centurion Vision System (with Ozil handpiece and torsional 
motion) 
 
Sample Size: 
105 subjects (bilateral cataract surgery; 210 eyes) 
 
Study Population: 
Subjects undergoing sequential bilateral cataract surgery that have 
the same cataract grade based on the LOCS III grading (including 
nuclear clarity and opalescence) in both eyes. 
§ Cataracts with a minimum grade of 2.0 for nuclear 
opalescence and 2.0 for nuclear color according to 
the LOCS III score are required to be considered for 
the study. 
Number of sites: 
One 
 
Study Design:  
Prospective, two-surgeon, randomized, paired-eye study; patients 
undergoing sequential, uncomplicated bilateral 
phacoemulsification using Unity VCS 4D phaco with a lower IOP 
setting in one eye and with a higher IOP in the other eye using 
Centurion Vision System with Ozil. 
Masking:  
None 
 
Primary Variables:  
Central corneal thickness at post-operative day 1 and corneal 
clarity at post-operative day 1. 

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Secondary Variables:  Central corneal thickness at post-operative day 8, corneal clarity at 
post-operative day 8, total aspiration time, total ultrasound time, 
and CDE. 
Exploratory Variable: Mesopic contrast sensitivity at post-operative day 1.  
 
Study Duration:  
Pre-operative to 8 days post-operative 
 
The study will be registered with clinicaltrials.gov 
This study will be conducted to match the protocol and follow any applicable 
requirements. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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5. Introduction 
Modern cataract surgery has seen remarkable advances, largely due to the introduction of 
sophisticated phacoemulsification platforms. These various platforms allow surgeons to 
achieve rapid vision correction and enhanced clarity for patients. One such recent 
advancement is the UNITY VCS platform from Alcon. This current technology is 
designed to maintain a lower IOP throughout the cataract phacoemulsification and 
aspiration process. 
Maintaining a lower IOP during cataract surgery is crucial as it mimics the natural 
conditions of the eye, allowing a reduction in stress and trauma usually associated with 
cataract removal. This approach to cataract surgery using the UNITY VCS is expected to 
result in several significant benefits for patients. It is expected to lead to greater corneal 
clarity with less corneal edema immediately after surgery, due to the cornea experiencing 
less disturbance and swelling. Evidence is needed to confirm that the UNITY VCS 
operating at a lower IOP delivers greater corneal clarity and less corneal edema in the 
post-operative period compared to the Alcon Centurion system with Ozil at a higher IOP. 
6. Objective 
To investigate how central corneal thickness and corneal clarity are affected when 
preforming phacoemulsification at a lower IOP setting using Unity VCS compared to 
how the two parameters are affected when preforming phacoemulsification using 
Centurion with Ozil at a higher IOP setting. 
7. Subjects 
7.1. 
Subject Population 
The subjects in this study will consist of individuals presenting to the study site that meet 
the inclusion criteria mentioned in the protocol who desire to undergo standard 
phacoemulsification cataract surgery. 105 subjects will be enrolled in total, with both 
eyes included within the study. Subjects will be informed about the details of the study 
and will sign a patient information and consent form to participate.  
7.2. 
Inclusion Criteria 
To be eligible for this study, subjects must have both eyes meet all the following 
inclusion criteria: 
• No prior ocular surgery, including corneal refractive surgery. 
•  Bilateral visually significant cataracts, similar in density with 1 grade of each other (a 
minimum grade of 2.0 on the LOCS III scale) prior to surgery. 

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• An equal dilated pupil size of ≥6mm without the use of pupil expansion devices. 
• Un-remarkable systemic health (can have a history of controlled type II diabetes and 
hypertension if the subject has a normal OCT at the baseline visit). 
• A normal CCT range of 540 μm ± 50 and no evidence of Fuchs’ dystrophy 
To be eligible for the exploratory endpoint, subjects must have both eyes meet the following 
criteria as well as the criteria above: 
• No other ocular pathology besides age-related cataracts. 
 
7.3. 
Exclusion Criteria 
A subject will be considered ineligible for this study if they, or either eye, meet any of the 
following criteria: 
• A history of corneal disease 
• Media opacification not due to a cataract 
• Compromised zonular stability 
• Retinal or retinal vascular pathology. 
• A history of glaucoma or any uncontrolled systemic disease. 
The primary investigator can, at any time, declare a patient ineligible or non-evaluable if 
medical evidence indicates that they are not suited for the trial. 
8. Study Details 
8.1. 
Study Design 
This study is a prospective, two-surgeon, randomized, paired-eye study. Subjects will 
undergo sequential, uncomplicated bilateral phacoemulsification using the Unity VCS 4D 
phaco operating at a lower intraocular setting in one eye and the Centurion Vision System 
with Ozil operating at a higher IOP setting in the other eye. 
The primary outcome measurements for this study are the following: 
• Central corneal thickness at post-op day 1 
• Corneal clarity at post-op day 1 
The secondary outcome measurements for this study are the following:  
• Central corneal thickness at post-operative day 8 
• Corneal clarity at postoperative day 8 
• Total aspiration time 

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• Total ultrasound time 
• Cumulative dissipated energy (CDE) 
The exploratory outcome measurement for this study is the following: 
• Mesopic contrast sensitivity at post-op day 1. 
 
8.2. 
Steps to Minimize Bias 
To minimize the double-organ bias, one of the subject’s eyes will be randomly assigned 
to have cataract surgery performed using the Alcon Unity VCS system and the other eye 
will be assigned to undergo cataract surgery using the Alcon Centurion Vision System 
with Ozil a week later. Subjects will be selected based on their own interest and the 
surgeons’ belief that they are suitable for cataract surgery. 
All measurements and procedures in the study will be standardized to minimize any bias. 
Post- operative treatments and medications will be standardized to minimize bias.  
9. Study Procedure 
9.1. 
Subject Enrollment and Informed Consent 
All subjects participating in this study will be required to meet the inclusion criteria and 
sign an approved informed consent document. Consent from each subject will be 
obtained before gathering any data for the study. All signed consent documents for this 
study will be maintained by the principal investigator and a signed copy will be provided 
for each subject.  
9.2. 
Study Visits 
All subjects will participate in 6 total visits during the study. Visits will include a baseline 
visit, two surgical visits (a week apart), a post operative day one visit for the first surgical 
eye, a post-operative day one visit for the second surgical eye combined with a post 
operative day eight visit for the first eye, and a post operative day eight visit for the 
second surgical eye. The visit schedule is displayed in the table below. 
 
 
 
Baseline 
Visit 
First 
Surgical 
Visit 
Post Op 
Day 1 
(first eye) 
Second 
Surgical 
Visit 
Post Op 
Day 1 (2nd 
eye) / Post 
Post Op 
day 8 (2nd 
eye) 

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Op Day 8 
(1st eye) 
CCT 
Measured with 
Pentacam 
X 
 
X 
 
X 
X 
Corneal 
Clarity 
Measured with 
Pentacam 
X 
 
X 
 
X 
X 
Total 
Ultrasound 
Time  
 
X 
 
X 
 
 
Total 
Aspiration 
Time 
 
X 
 
X 
 
 
CDE 
 
X 
 
X 
 
 
Mesopic 
Contrast 
Sensitivity 
 
 
X 
 
X (only 2nd 
eye) 
 
 
9.3. 
Study Methodology 
Patients will undergo sequential bilateral cataract surgery with the same cataract grade 
(based on LOCS III grading) in both eyes. Both surgeries will be included within one 
week of each other. 
The first surgical eye will be randomly assigned at the day of the surgery to be performed 
with either the Alcon Unity VCS system using 4D or the Alcon Centurion Vision System 
with Ozil. Surgery with the Unity VCS arm will be performed with a lower IOP setting  
(< 40). Surgery with the Centurion with Ozil arm will be performed with a higher IOP 
setting (≥ 60). 
For each surgical procedure, a 2.3 mm temporal clear corneal incision will be performed 
using a trapezoidal blade. Each surgical case will be performed with Viscoat and Provisc 
viscoelastics. Anesthesia for the surgery will include topical lidocaine with MKO melt or 
crushed Xanax.  
Horizonal phaco-chop techniques with pre-established and optimized fluid system 
settings will be standardized to the maximum extent possible. Each surgical system’s 
settings are displayed below. 
 
 

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IOP (mmHg) 
Vacuum 
(mmHg) 
Asp Flow 
(cc/min) 
Other Settings 
Centurion 
≥ 60 
Sculpt: 130 
Chop: 575 
Epi: 450 
Sculpt: 26 
Chop: 42 
Epi: 35 
Irrigation Factor: 1.3 
Torsional Amplitude: 
60 
Sculpt and Chop: 60 
Epi: 35 
Longitudinal Pulse 
Duration: 94 
Vacuum Threshold: 94 
Longitudinal/Torsional 
Ratio: 0.8 
Unity VCS 
<40 
As close as 
possible to 
Centurion 
settings 
(identical is 
preferred if 
possible) 
As close as 
possible to 
Centurion 
settings 
(identical is 
preferred if 
possible) 
4D Phaco 
Surgeries will be performed 1 week apart from each other. During the procedures, 
intraoperative phacoemulsification metric will be recorded from the GUI: total aspiration 
time, total ultrasound time, and CDE. 
All post operative treatments and medications will be standardized to include 
Prednisolone Acetate/Moxifloxacin/Bromfenac 3 in 1 on a standardized schedule (4-3-2-
1 weekly for each eye).  
All measurements of central corneal thickness will be measured with a Pentacam. 
Corneal clarity will be measured with a Pentacam Corneal Optical Densitometry in a dark 
room or with a drape placed over the subject. 
Post operative visits will occur on days 1 and 8 following the surgery for both eyes. Post 
operative day 1 for the second eye and post operative day 8 for the first eye will fall on 
the same day so the visits will be combined. 
Mesopic contrast sensitivity will be completed on both post operative day 1 visits with 25 
subjects that will undergo bilateral monofocal IOL implantation. Subjects are required to 
have no co-morbidities other than age-related cataracts. Testing for this parameter will be 
completed using the Pelli-Robson contrast sensitivity chard with a 3cd/ m2 LED 
illumination cabinet. Subjects will sit 1 meter from the cabinet to the outer canthus of the 
eye for testing. 
 

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9.4. 
Discontinued Subjects 
Subjects can be discontinued from the study at any time based on the judgement of the 
primary investigator. Reasons for discontinuation include an adverse event, lost to follow 
up, a subject decision unrelated to an adverse event, a protocol violation, treatment 
failure, or other.  
 
10. Analysis Plan 
All study analysis will be performed using SATA software (v16.1, College Station, 
Texas). All continuous variables will be summarized using mean and standard deviations. 
The results of the tests of normality on each measure (the Shapiro-Wilk test) will 
determine whether the paired t-test or the Wilcoxon signed rank test will be used to 
evaluate the hypothesis. 
A graphical testing strategy will be employed to control type one error at the 0.05 
significance level due to the multiple hypotheses involved in the study. Each primary 
hypothesis will be tested against a 0.025 significance level. If either primary hypothesis is 
rejected, the secondary endpoints will be tested at the 0.025 significance level in 
hierarchical fashion. If both primary hypotheses are rejected, the secondary endpoints 
will be tested at the 0.05 significance level. If all of the secondary hypotheses are rejected 
at a 0.025 level of significance, the primary hypothesis unrejected at the 0.025 level will 
be retested at the 0.05 significance level. 
Descriptive statistics (mean, standard deviation, etc) will be collected for the following 
endpoints: CCT at post op day 8, corneal clarity at post op day 8, and total aspiration 
time. 
A mixed effects linear regression will be performed to test the trend overtime for CCT by 
group, accounting for paired data. Another mixed effects linear regression will also be 
performed to test the trend over time in corneal clarity by group, accounting for paired 
data. 
11. Sample Size Justification. 
Assuming a power of 80 percent, a significance level of 0.025, and a paired eye design, 
older studies (Rauen 2024, Spaulding 2025, Liu 2023, Hovanesian 2025, and Kokubun 
2022) a difference of means of central corneal thickness on post op day 1 is expected to 
be around 24.4 μm with a standard deviation of 76.1. While no data is available 
examining corneal clarity, a closely related endpoint is corneal edema. A difference in 
means for corneal edema on post op day 1 is expected to be 0.027 with a standard 

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deviation of 0.6. It is expected that a study population of 105 patients, or 210 eyes, will 
provide sufficient data to characterize a difference in performance between the two 
cataract surgery systems.  
12. Confidentiality of the Study 
This study is confidential and will not be discussed with anybody not involved in the 
study. Results will be submitted for a publication and a presentation of the study will be 
made to deliver at meetings and conferences. A manuscript will be submitted to journals 
for the study to be published. The names of subjects and other identifying information 
will not be included in any of the materials published from this study. Information 
collected will only be used for study purposes and will not be sold to any third parties.  
13. Adverse Events and Quality Complaints 
Study subjects will have the opportunity at each visit to mention any problems they are 
experiencing, and the investigator will inquire about any adverse events directly. 
 
If any adverse events are found to have taken place, an adverse event form will be filled 
(AEF) will be filled out. A separate form is required for every event that takes place. 
Documentation surrounding an adverse event must include the date of symptom onset, 
outcome, date of resolution, severity, remedying steps, and a relationship to the study 
treatment. Regardless of severity, all adverse events will be reported to a medical 
monitor. Serious adverse events will be reported to the IRB/IEC according to their 
requirements.  
 
The primary investigator will determine whether the adverse event occurred due to the 
study treatment or because of outside factors. An assessment of causality will also be 
performed by the medical monitor of the study. 
 
14. Ethical Considerations 
This study will be conducted following the ICH guidelines in compliance with Good 
Clinical Practices. All applicable regulations and requirements will be adhered to. This 
study will also be held in compliance with the Institutional Review Board (IRB) and will 
obtain approval by an IRB/ethics committee prior to beginning. 
 
 
 
 

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15. References 
1. Rauen MP, Joiner H, Kohler RA, O&#39;Connor S. Phacoemulsification using an active 
fluidics system at physiologic vs high intraocular pressure: impact on anterior and 
posterior segment physiology. J Cataract Refract Surg. 2024 Aug 1;50(8):822-827. doi: 
10.1097/j.jcrs.0000000000001457. PMID: 38595209. 
2. Spaulding J, Hall B. Efficiency of phacoemulsification handpieces with high and low 
intraocular pressure settings. J Cataract Refract Surg. 2025 Mar 1;51(3):218-221. doi: 
10.1097/j.jcrs.0000000000001581. PMID: 39602355. 
3.  Liu Y. et al. Comparison of the clinical outcomes of Centurion active fluidics system 
with a low IOP setting and gravity fluidics system with normal IOP setting for cataract 
patients with low corneal endothelial cell density. Front Med 10:1294808 (2023) 
4.  Kokubun, T. et al. Verification for the usefulness of normal tension cataract surgery. The 
126th Annual Meeting of the Japanese Ophthalmological Society (JOS) (Osaka, Japan, 
2022). 
5. Hovanesian, Rauen. ASCRS 2025. Surgical Efficiency and Postoperative Corneal Clarity 
with Near Physiologic Vs High IOP Settings during Phacoemulsification. 
https://ascrs.confex.com/ascrs/25am/meetingapp.cgi/Paper/107679 
6.  Rauen AAO 2024. Phacoemulsification at High IOP and Physiologic IOP: Impact on 
Anterior and Posterior Segment Physiology