Tolerance to Residual Astigmatism and Defocus in Eyes With a Non-diffractive Extended Depth of Focus (EDoF) Intraocular Lens
Conditions: Lenses, Intraocular
Sponsor: Clínica Rementería

Title: Tolerance to residual astigmatism and defocus in eyes with 
a non-diffractive extended depth of focus (EDoF) intraocular lens 
NCT05392998 
21 April 2021 
 

Tolerance to residual astigmatism and defocus in eyes with a 
non-diffractive extended depth of focus (EDoF) intraocular lens 
 
INTRODUCTION 
 
Multifocal intraocular lenses have been shown to be a good option for cataract 
surgeons aiming to offer improved vision at different distances. Trifocal IOLs provide 
enhanced vision at far, intermediate and near distances and have overcome the 
characteristic V-pattern with 2 peaks corresponding to near and far vision provided by 
bifocal IOLs.1 Although multifocal IOLs could increase spectacle independence in 
patients undergoing cataract surgery, these lenses could also increase some visual 
disturbances such as glare or haloes.2  
“Extended depth of focus” (EDoF) IOLs are currently available for cataract 
surgeons. They employ different optical technologies to achieve extended vision3, 
increasing the range of vision while minimizing visual disturbances induced by classical 
diffractive multifocal designs.3 In fact, current clinical results show that EDoF lenses 
could increase the range of vision from far to intermediate distances and reduce the 
perception of visual disturbances of the patients.4  
In addition, while it has been reported that issues such as biomechanical 
properties of the cornea, inaccurate calculations, or misalignments of the IOLs may 
lead into residual refractive errors that will likely decrease the visual quality of patients 
with bifocal or trifocal IOLs5, less is known about their impact on EDoF designs.  
Therefore, regardless of the optical improvements achieved by EDoF lenses, 
better knowledge of the spherical and/or astigmatic tolerance of EDoF IOLs is crucial 

for an appropriate surgical planning and for avoiding postoperative refractive 
corrections. Thus, the aim of this study is to analyze the impact of mild amounts of 
residual spherical defocus and astigmatism in patients implanted with a novel non-
diffractive EDoF IOL. 
 

PATIENTS AND METHODS 
Prospective study, which will include patients undergoing bilateral cataract 
surgery with bilateral implantation of a Vivity non-toric lens 
Performed at Clínica Rementería, Madrid, Spain  
Inclusion criteria: 
-Patients >40 years old undergoing bilateral cataract surgery with Vivity IOL 
implantation 
Exclusion criteria: 
 corneal astigmatism ≥1.0 diopters (D) 
 amblyopia 
 previous ocular surgery 
  presence of ocular pathologies 
  abnormal iris 
 intra- or postoperative complications 
 postoperative distance corrected visual acuity (DCVA) < 20/20 
  postoperative refractive astigmatism > 0.50D. 
 
Postoperative clinical assessment 
Patients will be evaluated one day, one week, one month, and three months 
postoperatively. Patients fulfilling inclusion criteria will be approached to be included 
in the study at the three-month visit.  
Explorations to be performed at the three-month visit 

 Uncorrected distance, intermediate (60cm) and near (40cm) visual 
acuity (VA) with an ETDRS chart, followed by subjective refraction.  
 Once the best distance correction is obtained, further VA evaluation 
procedures will be performed with the FrACT3.9.9a version of the 
Freiburg Acuity Test software package.11 Once patients achieve the best 
distance correction (reference situation), a monocular analysis of VA at 
distance vision will conducted under different induced conditions.  
o  both a myopic and hyperopic defocus of 0.50 D will be 
simulated 
o after these measurements, a mixed astigmatism with different 
orientation will also induced by adding a combination of -0.25 
diopter (D) spherical and 0.50 D cylindrical lenses placed in 
vertical (against the rule - ATR), oblique and horizontal (with the 
rule – WTR) positions.  
 
Statistical Analysis 
The calculation of the required sample size was based on monocular CDVA. A 
difference of 0.2 logMAR units was assumed to be clinically significant and a standard 
deviation of 0.05 was considered.12 Based on this assumption and α of 0.05 and power 
of 0.8, it was calculated that 25 eyes were required.  
Data analysis will be performed using SPSS for Windows V.20.0 (SPSS Inc, 
Chicago, IL). The normal distribution of variables will be assessed using the 
Kolmogorov-Smirnov test. A repeated- measures analysis of variance (ANOVA) will be 

used to gauge any statistically significant difference within the different situations. 
Post hoc multiple comparison testing will be performed using the Holm-Sidak method. 
Differences will be considered to be statistically significant when the P value is <0.05 
(i.e., at the 5% level).   
 
Protocol approved by Hospital Clínico San Carlos, code C.I. 21/365-O_P 

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