These lenses consist of an RGP center with a
soft skirt edge. They combine the benefits of rigid lens optics,
including better lens contraction and decreased aberrations, along
with the comfort of a soft lens. The results are improved vision and
increased wearing time. Since comfort is the primary barrier to
the greater popularity of gas permeable lenses, hybrid contact lenses are
an excellent choice for people who want the clarity of a GP lens and
wearing comfort that more closely resembles that of soft lenses.
THE RGP LENS PARAMETERS: The lens parameters that need to be
finalized for an individual eye are
Base Curve
Power
Diameter
Optics Zone
Optics Zone Diameter
Peripheral curve radius/width
Centres thickness
Edge design
Tint
Material
The Ideal RGP Lens Fit: The lens fitting is evaluated in two ways.
- Static: With the lens in stationary positions, the fluorescein
pattern with central alignment, mid peripheral minimal
clearance and adequate pooling in the peripheral curves is
evaluated. - Dynamic: Evaluated the moment of the lens with the blink
and further judge the tear exchange under it is called the
dynamic fitting evaluation.
SyneregEyes currently is the sole manufacturer of FDA-
approved hybrid contact lenses sold in the United States. The
company makes a variety of hybrid lenses sold under the Duette,
Ultra Health and SyneregEyes brands, including progressive and
multifocal hybrid lenses for the correction of presbyopia and designs
for the corrections of keratoconus and other corneal problems.
Movement: The movement of the lens is an important issue the rigid
lens fitting because:
a) It facilitates tear exchange.
b) It removes the debris under the lens.
c) There is significant exchange of oxygen under the RGP during
blink.
An ideal rigid lens will move 1 to 1.5 mm vertically with each
blink. This movement should also be smooth indicating an
alignment fit.
Hybrid lenses are easy to maintain. Unless you are wearing daily
lenses that you discard each night, all contact lenses require regular
cleaning and proper storage. Following cleaning and storing
instructions significantly reduces your risk of contracting a potentially
serious eye infection. However, hybrid contact lenses are no more
difficult to care for than other lenses. In general, you will need to
clean your lenses every time you remove them and store them in a
clean case filled with fresh hybrid solution. Most people quickly
adapt to this routine and find that it takes just a minute or two each
night.
Hybrid lenses have some unique characteristics that make them
more suitable for some people than others. The individuals who
report the highest satisfaction with lenses typically:
Have irregular corneal astigmatism.
Have both presbyopia and astigmatism.
Complain of lens rotation with soft contacts.
Want the superior visual quality of RGP lenses with more
comfort.
Currently wear soft contacts but still desire better vision.
It appears that reverse geometry corneal reshaping RGP lenses may
not only help correct your vision now but also slow the progression
of myopia over time. That’s especially important for kids, who
depend so fully on their vision foe learning, and whose myopia may
still be able to be slowed down or halted. These RGPs are used in
orthokeratology, a treatment in which the patient wears lenses
overnight to correct vision by reshaping the cornea.
The practitioner has many parameters to choose from in deciding the
optimal fit for a rigid lens. Although system-designed lenses are
suitable for many, optimum comfort or visual acuity should not be
compromised if an ideal fit cannot be achieved.
Also, consult with your eye doctor and task if hybrid contact lenses
are the best choice for your lifestyle and visual needs.
