Comparative Global Literature Reviewof Visual and Optical Quality of
Refractive, Diffractive, and HybridIOL Designs
James P. McCulley, MDDepartment of Ophthalmology
University of Texas Southwestern Medical Center at Dallas
Dr. McCulley is a consultant for Alcon Laboratories, Inc.
Purpose & Methods
PURPOSE: To investigate whether trends in superiority existfor optical characteristics and patient outcomes when making pairwise comparisons between 2 of the following 3 IOL types: refractive, diffractive, and hybrid of refractive with apodized diffractive.
METHODS: Literature searches for published articles
OvidSP Database (MEDLINE, EMBASE pooled), JRS, and JCRSOvidSP Database (MEDLINE, EMBASE pooled), JRS, and JCRS
Keyword search #1:refractive AND diffractive AND (multifocal
OR bifocal) AND intraocular lens
Keep only the applicablecomparative studies
Keyword search #2:compar* AND (multifocal OR bifocal)NOT monofocal AND intraocular lens
*Wildcard asterisk returns “comparative,” “compared,” “comparison,” etc.All results restricted to English language
23 unique journal articles23 unique journal articles
Methods:Pooled Source Data
23 studies (5 bench, 18 human); total 1411 eyes
(Full-Optic)(Full-Optic)
Diffractive IOLsDiffractive IOLs Refractive Refractive IOLsHybrid IOLsHybrid IOLs
(Refractive Outer Ring,(Refractive Outer Ring,Apodized Diffractive Apodized Diffractive
Center Disk)Center Disk)
Model Studies, n Model Studies, n Model Studies, n
Tecnis®,AMO
11Array®,AMO
12ReSTOR®,
Alcon17*
CeeOnTM,Pfizer
6ReZoom®,
AMO10
A-TwinTM,Acri.Tec
3
A-LISATM,Acri.Tec
2
825x +4,3M
1
Older IOL names or manufacturers updated to most recent.*16 Spherical SN60D3 or SA60D3, 1 Aspheric SN6AD3, 0 Aspheric SN6AD1
Study designs• Bilateral groups: 9 studies• Contralateral: 1 study• By eye: 8 studies• Bench: 5 studies
Lens Characteristics
Tecnis® A-LISATM ReZoom® ReSTOR®
Lens Type
Multi-Piece
Single-Piece
Multi-piece
Single- or Multi-Piece
Lens Material
Polysiloxaneor
acrylic
Foldable acrylate with 25% watercontent,
hydrophobic surface,and UV-absorber
Hydrophobic acrylic optic, poly-methyl
methacrylate (PMMA) haptics
UV-absorbing & blue light
filtering acrylate/
methacrylate copolymer
Diffractive IOLs Refractive IOLs Hybrid IOLs
Results:Optical Bench Test Outcomes
5 Studies; 5 result types; 18 pairwise superiorities Outcomes included defocus transfer function, night driving photograph,
modulation transfer function (near, distance, various pupil sizes),Strehl ratio, USAF target resolution
Top three superiorities (others only 1 superiority)– Hybrid IOLs superior over refractive IOLs, n=6– Diffractive IOLs superior over refractive IOLs, n=5– Hybrid IOLs superior over diffractive IOLs, n=4
0
2
4
6
8
Hybrid Refractive Diffractive Hybrid Diffractive Refractive
Pairwise comparator
Co
un
t o
f re
su
lts
Diffractive vs… Hybrid vs…Refractive vs… Winners
Results were not tabulated unless a superiority was observed(ie, equivalences and similarities not counted)
Results:Near Visual Acuity (≤40 cm)
14 of 18 studies found pairwise near VA superiorities Includes UCVA, BCVA, photopic (± glare), mesopic (± glare),
defocus curve data, monocular/binocular, various contrast levels
Top three superiorities:– Diffractive IOLs superior over refractive IOLs, n=26– Hybrid IOLs superior over refractive IOLs, n=8– Hybrid IOLs superior over diffractive IOLs, n=5
Results were not tabulated unless a superiority was observed(ie, equivalences and similarities not counted)
0
10
20
30
Hybrid Refractive Diffractive Hybrid Diffractive Refractive
Pairwise comparator
Co
un
t o
f re
su
lts
Diffractive vs… Hybrid vs…Refractive vs… Winners
Results:Intermediate Visual Acuity (>40 cm to 3 m)
10 of 18 studies found pairwise intermediate VA superiorities Includes UCVA, BCVA, photopic (± glare), mesopic (± glare),
defocus curve data, monocular/binocular, various contrast levels
Trends in superiority were not consistent:– In refractive vs diffractive IOLs: 7 for refractive, 5 for diffractive– In diffractive vs hybrid IOLs: 5 for diffractive, 1 for hybrid – In refractive vs hybrid IOLs: 5 for refractive, 0 for hybrid
All hybrid studies were for +4.0 D IOLs, not +3.0 D IOLsResults were not tabulated unless a superiority was observed
(ie, equivalences and similarities not counted)
0
2
4
6
8
Hybrid Refractive Diffractive Hybrid Diffractive Refractive
Pairwise comparator
Co
un
t o
f re
su
lts
Diffractive vs… Hybrid vs…Refractive vs… Winners
Intermediate Visual Acuity:SN6AD1 versus SN6AD3 IOLs
-0.1
0
0.1
0.2
0.3
0.4
0.5
1.5 1 0.5 0 0.5 -1 -1.5 -2 -2.5 -3 -3.5 -4
+3.0 D IOL, 116 bilateral patients
+4.0 D IOL, 114 bilateral patients
The new +3.0 D IOL (SN6AD1) uses the existing +4.0 D IOL (SN6AD3) platform
Vergence, D
Vis
ual
acu
ity,
lo
gM
AR
Intermediate visual acuityis improved with +3.0 D IOL
Near focus is farther out from the eye with +3.0 D IOL
40 cm50 cm33 cm
Maxwell et al. J Cataract Refract Surg. 2009: 35; 2054-2061
Results:Far Distance Visual Acuity (>3 m)
4 of 18 studies found pairwise far VA superiorities Includes UCVA, BCVA, photopic ( photopic + glare, mesopic, mesopic +
glare, defocus curve data, monocular/binocular, various contrast levels
Top three superiorities:– Hybrid IOLs superior over diffractive IOLs, n=8– Tie for second place: refractive vs diffractive, 2 superiorities each
Results were not tabulated unless a superiority was observed(ie, equivalences and similarities not counted)
0
2
4
6
8
10
Hybrid Refractive Diffractive Hybrid Diffractive Refractive
Pairwise comparator
Co
un
t o
f re
su
lts
Diffractive vs… Hybrid vs…Refractive vs… Winners
Underpowered/Unclear Comparisons
Visual disturbances: superiorities found by 2 of 7 studies– Diffractive > Refractive, negative dysphotopsia (n=1) and halo (n=1)
Contrast sensitivity: superiorities found by 7 of 9 studies– Various spatial frequencies and lighting conditions– Diffractive>Refractive, n=3– Hybrid>Refractive, n=3– Refractive>Diffractive, n=4– Refractive>Hybrid, n=3
Higher-order aberrations: superiorities found by 3 of 4 studies– Included coma, spherical aberration, various pupil sizes– Hybrid>Refractive, n=12 results– Diffractive>Hybrid, n=8 results
Reading acuity and speed: superiorities found by 3 of 3 studies– Various lighting conditions, distances, correction– Top acuity superiority: Diffractive > Refractive (n =15 results)– Top speed superiority: Diffractive > Refractive (n=9 results)
Summary
Based on the number of results from articles comparing one type of multifocal IOL to another, the following possible trends were observed:
– For published optical quality results,• Hybrid > Refractive• Diffractive > Refractive
– For published visual acuity results,• Near vision
– Diffractive > Refractive– Hybrid > Diffractive– Hybrid > Refractive
• Intermediate vision – Refractive vs diffractive: differences not clear– Refractive and diffractive superior to hybrid (+4.0 D model),
but SN6AD1 (+3.0 D model) improves intermediate visual acuity• Distance vision
– Hybrid > Diffractive– Tie for second place: Refractive vs Diffractive
References(Database for Literature Review)
1. Alfonso et al. J Cataract Refract Surg 2008;34:1848-1854.2. Alio et al. J Cataract Refract Surg 2004;30:2494-2503.3. Artigas et al. J Cataract Refract Surg 2007;33:2111-2117.4. Chang. J Cataract Refract Surg 2008;34:934-941.5. Chiam et al. J Cataract Refract Surg 2007;33:2057-2061.6. Choi et al. J Refract Surg 2008;24:218-222.7. Gunenc et al. J Refract Surg 2008;24:233-242.8. Hutz et al. J Cataract Refract Surg 2006;32:2015-2021.9. Hutz et al. J Refract Surg 2008;24:251-256.10. Maxwell et al. J Cataract Refract Surg 2009;35:166-171.11. Mester et al. J Cataract Refract Surg 2007;33:1033-1040.12. Ortiz et al. J Cataract Refract Surg 2008;34:755-762.13. Palmer et al. J Refract Surg 2008;24:257-264.14. Pepose et al. Am J Ophthalmol 2007;144:347-357.15. Pieh et al. Arch Ophthalmol 2002;120:23-28.16. Renieri et al. Eur J Ophthalmol 2007;17:720-728.17. Richter-Mueksch et al. J Cataract Refract Surg 2002;28:1957-1963.18. Schmidinger et al. J Cataract Refract Surg 2006;32:1650-1656.19. Schwiegerling. J Refract Surg 2007;23:965-971.20. Toto et al. J Cataract Refract Surg 2007;33:1419-1425.21. Walkow et al. Ophthalmology 1997;104:1380-1386.22. Weghaupt et al. J Cataract Refract Surg 1998;24:663-665.23. Zelichowska et al. J Cataract Refract Surg 2008;34:2036-2042.
