title: A	Double	Masked	Randomised Crossover	Trial	of	
two	Silicone	Hydrogel	Multifocal	Contact	Lenses
Creators: name: Ashleigh, Claudia
Publisher: name: London South Bank University
Year: 2017

description: Purpose:	
To compare	 visual	 performance	 and	 acceptance	 of	 two	 different	
designs	 of	 monthly disposable	 silicone	 hydrogel	 multifocal	 contact	
lenses,	the	Air Optix	Aqua	Multifocal	and	the	Biofinity	Multifocal.
Methods:
A	 double	 masked	 randomised	 crossover trial	 of	 62 presbyopic	
participants	 (between	 41	 and	 60	 years	 of	 age)	 was	 conducted.	
Participants were	 randomised	 first	 into	 either	 the	 Air Optix	 Aqua	
Multifocal	or	the	Biofinity	Multifocal	lens	to	be	worn	for	four	weeks	
for	each	modality.	There	was	a	washout period	of	one	week	before	
wearing	 the	 second	 option.	 Measurements	 included	 binocular	
photopic distance	 visual	 acuity	 (VA),	 binocular	 photopic	 near	 VA,	
stereoacuity	 at	 distance	 and	 near	 and	 contrast	 sensitivity	 in	
photopic,	 mesopic	 and	 scotopic	 lighting	 conditions.	 Subjective	
participant	 experience for	 quality	 of	 vision was	 collected	 using	 the	
VF-14	 visual	 function	 questionnaire	 and	 a	 specially	 designed	 daily	
diary.
Results:
Fifty-seven	 participants	 completed	 both	 periods	 of	 this	 crossover	
study	 (mean	 age	 52.9,	 43	 females,	 14	 males).	 The	 difference	 for	
binocular	 photopic	 distance	 and	 near	 VAs between	 the	 Air Optix	
Aqua	and	Biofinity	Multifocal were	marginal (distance: p&gt;0.13, near:	
p&gt;0.24).	Differences for	 stereoacuity	at	 distance	and	 near	 between	
the	 Air Optix	 Aqua	 and	 Biofinity	 Multifocal were not	 statistically	
significant	 (distance: p=0.33,	 near:	 p=0.36)	 and	 measurements	 for	
contrast	 sensitivity	 in	 mesopic	 and	 scotopic	 lighting	 conditions	
showed	no	statistically	significant	difference	between	the	lens	types
(mesopic:	p&gt;0.18 and	scotopic:	p&gt;0.31).	Photopic	contrast	sensitivity	showed	statistically significant	results	and was	marginally	better	with	
the	 Air	Optix	 Aqua	Multifocal	than	 Biofinity	Multifocal	 (p=0.013	 by	
paired	 t-test	 and	 p=0.018 Wilcoxon	 Signed	 Ranks	 test).	 This was	
judged	unlikely	to	be	of	clinical	significance	and	most	likely	a	chance	
finding.	 Marginal	 but	 not	 statistically	 significant	 preferences	 were
found	for	the	data	of	the	VF-14	visual	function	questionnaire	and	the	
daily	diary	with	participants	preferring	the	Air Optix	Aqua	Multifocal	
for	 distance	 vision	 (distance	 vision	 scores: Wilcoxon	 Signed	 Ranks	
test: 79-76%)	and	reporting	more	satisfaction	with	intermediate	and	
near	 vision	 with	 the	 Biofinity	 Multifocal	 lens	 design (intermediate	
vision	 scores:	 66-60%	 and	 near vision	 scores:	 74-72%). Comfort	
scores	were	equally	high	 for	both	lens	designs	 (comfort	 scores:	 78-
82%). 43 participants	(75%)	felt	soft	multifocal	contact	lenses	were	a	
good	 alternative	 to	 spectacles	 and	 33	 participants	 (58%) were	
continuing	 to	 use	 one	 of	 the	 two	 designs	 one	 year	 after	 the	 trial	
ended. Of	these, 17	wearers	(51%)	were	wearing the	Air Optix	Aqua	
and	16	(49%)	the	Biofinity	Multifocal	lens.	
Conclusions:
There	were no	consistent differences in	visual	performance	between	
the	 Air Optix	 Aqua	 Multifocal	 and	 the	 Biofinity	 Multifocal	 lens	
design.	 The	 Air Optix	 Aqua	 multifocal	 was	 found	 to	 be	 marginally	
superior in	 participants’ subjective scores	 for	 binocular	 distance	
vision and	 the	 Biofinity	 Multifocal	 for	 binocular intermediate	 and	
near	vision.	Based	on	feedback	at	follow	up,	presbyopic	participants	
in	this research	rated	soft	silicone	hydrogel	multifocal	contact	lenses	
a	good	alternative to	spectacle	wear.  Key	Words:	
Presbyopia,	 multifocal,	 silicone	 hydrogel, contact	 lens,	 double	
masked	crossover, comparison	 study,	visual	 function	questionnaire,	
daily	diary