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The WIOL-CF Accommodative Intraocular Lens
that accommodative IOLs offer similar distance vision to monofocal Figure 1: Geometry of the WIOL-CF
IOLs and improved near vision during the first six months after
implantation, but loss of this latter effect in the first year post-
Meniscoid anterior
operatively due to capsular opacities.
10–12
surface
The WIOL-CF Accommodative
Intraocular Lens
.:
1.1–1.4mm
The WIOL-CF accommodative IOL was invented by Professor Otto CT
Wichterle and his collaborators at the Institute of Macromolecular
Hyperboloid surface
Chemistry in Prague. Its design is based on the biomimetic principle:
contacting posterior
according to this principle, the hydro gel material used and the lens
capsule
geometry simulate some of the key properties of the crystalline
OD: 8.6–9.0mm
lens itself. The WIOL-CF can be actually considered more as a natural
product and not a typical engineered one. The material used for the
Figure 2: Plasticised WIOL-CF Ready for Folding
construction of the WIOL-CF has a high water content, a negative
surface charge, a high carboxylate content and a low refractive index.
These parameters ensure maximum biocompatibility, resistance to
calcification and elimination of cell attachment or spreading, which
are considered the main causes of lens and posterior capsule
opacification. The geometry of the lens can be distinguished by its
large outside diameter, convex anterior, posterior surfaces and
relatively large sagittal depth (see Figure 1). These characteristics
were selected to secure adequate contact with the biggest part of the
posterior capsule but not alteration of the capsule shape. Additionally,
the large continuous aspheric optics ensure lens centricity and
reduce reflections and halos, which can cause night vision problems.
The lens design is intended to provide pseudoaccommodation
capability, facilitating near vision.
Figure 3: Folded WIOL-CF Ready for Implantation
The large optics of the WIOL-CF ensure good optical performance even
in large-diameter pupils in scotopic conditions. The large optical zone
gives the lens a significant advantage over other IOLs, especially in
young patients, in mesopic conditions and for vitroretinal surgery
candidates. Disturbing optical side effects that can sometimes be
observed with smaller-optic IOLs are not seen with the WIOL-CF. The
WIOL-CF can be inserted through a 2.8mm incision. The small incision
required can significantly reduce the induced stigmatism. The hydro
gel lens is partly dehydrated and temporarily plasticised by a water-
miscible non-toxic plasticiser. In its plasticised state, the lens is smaller
and much stronger than in its fully hydrated state, and can be folded
‘taco-style’ prior to implantation (see Figures 2 and 3). Once the lens is
inserted, it unfolds inside the capsule and gradually hydrates using the
fluid present in the eye. Complete hydration is achieved within the first power, the movement of the lens causes an increase or decrease in
48 hours, and full equilibrium with the eye fluids occurs. the distance between the lens plane and the retina.
The shape of the lens may be biconvex, planoconvex or Another theory to explain the accommodative effect of the WIOL-CF is
convex–concave, according to the dioptric power. The suggested anterior–posterior movement of the implant caused by increases and
A-constant for implantation is 120 and the recommended formula for decreases in the pressure of the vitreous body, which are due to
the calculation of the dioptric power of the WIOL-CF is SRK II or bulbus deformation created by the action of certain external muscles
SRK – T. Pseudoaccommodation up to 2.5 diopters can be achieved normally responsible for eye movement. The multifocality of the lens
with the WIOL-CF. Its soft material and continuous contact with the itself created by the hyperbolic posterior surface in conjunction with
posterior capsule allows some axial movement and deformation of the multifocality of the cornea facilitates near vision, generating some
the lens following ciliary muscle contraction. degree of pseudoaccommodation. Of course, in order to achieve
optimum results it is important to clarify to the patient that near vision
Possible Mechanisms of Pseudoaccommodation accommodation requires effort and time. Patients should be trained to
Several mechanisms are responsible for the accommodative effect of utilise the accommodative features of the lens, which will allow them
the WIOL-CF. The first is the anterior–posterior movement of the to lead an active life without being spectacle-dependent. The extent of
implant due to tightening and relaxation of the ciliary muscle. This the pseudoaccommodation properties of the WIOL-CF cannot be
type of accommodation is similar to natural accommodation, but predicted, and patients should be thoroughly informed of this. In every
rather than occurring due to a change in lens curvature and refractive case, realistic expectations should be established before surgery.
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