Universal intraocular lens and a method of measuring an eye chamber size

A universal intraocular lens that may be implanted in an eye, in an anterior chamber, in a posterior chamber and in any size eye chamber wherein a tangential flexible strand is attached to a lens at one end and the other free end is formed into a snag resistant ring, or disc which is approximately circular to avoid injury to delicate eye tissue during implantation, centration or removal of said lens.

An intraocular lens is normally implanted in the anterior or posterior 
chamber of an eye following extraction of a cataractous lens. Since 
replaceable lenses are different for use in a posterior chamber than use 
in an anterior chamber, two different lenses must be kept in stock. In 
addition, the eye chamber could vary in size, again requiring additional 
varied sizes in stock. 
The most widely used Shearing type lenses are utilized only for posterior 
chamber implantation. It is a plastic lens having two opposed flexible 
strands, one a superior loop and the other an inferior loop, wherein the 
free ends are arched and end in a point. This makes it extremely difficult 
for a surgeon to master the implantation of the superior loop during 
realignment or removal of the lens without injuring the delicate tissue of 
an eye. 
One of the main objects of this invention is to avoid this snagging point 
of the loop by replacing it with a snag resistant disc, ring or closed 
circular loop. 
Another object is to provide such a snag resistant strand so that both 
right and left handed surgeons may be able to use the same lens, thus 
eliminating the need for a specially designed lens for a left handed 
surgeon. 
Another object is to provide a universal lens that can be used in an 
anterior or posterior chamber of an eye and can be equally used in a 
small, medium or large eye chamber size, thus avoiding the stocking of a 
large number of different types and sizes by hospitals and surgeons. 
Another object is to provide just one type of universal lens for all eye 
transplants so that all surgeons will become familiar with it and greater 
safety can be provided for the patients. 
Another object is to so tangentially shape the flexible strand as to cause 
the lens to self-center when implanted. 
A further object is to use the distance between the ring edge and the lens 
edge to determine the size of an eye chamber.

In FIG. 1, there is shown intraocular lens 10 of this invention, having a 
lens body 12 measuring 6 mm in diameter and centration openings 17 that 
measure 0.25 mm in diameter which may be used for alignment of the lens 
during implantation of the lens. The lens is formed of clinical quality of 
polymethymethacrylate and has an overall length of 13.5 mm inclusive of 
the flexible strands 14 which are tangentially curved towards the lens 
circumference to the left on the superior strand while the inferior strand 
is tangentially curved to the right. This enables a surgeon to implant the 
lens with minimal force and permits the lens to be self-centering. The 
snag resistant looped disc 16 and strand 14 are integrally molded to the 
body of the lens. The thickness of the strand is 0.25 mm and the lens 
thickness is 0.85 mm as shown in FIG. 2. 
In FIG. 3, there is shown another form of the intraocular lens 10' of this 
invention. The body 21 of the lens and the resilient strands 25 supporting 
the snag resistant rings 23 are integrally molded to the lens body, 
however to provide a sturdier base 24, the shape is molded into a 
triangular design which supports the flexible strand and said strand is 
shaped to be tangential to the lens circumference. In use, this lens is an 
actual commercial model and upon implantation, it automatically becomes 
self centered. It is essential that this ring be at least three times 
greater than the width of the flexible strand and at least one fifth as 
great as the width of the lens to result in smoothly guiding the snag 
resistant ring across the iris or other eye tissue when implanting the 
lens in either an anterior or posterior chamber which is small, medium or 
large. When this lens is implanted into a posterior chamber as shown in 
FIG. 4, the snag resistant free end rings will snugly fit into the pocket 
found near the stationary zone of the iris 26. The lens when so implanted 
is self-centering and the rings lie in a plane sufficiently close to the 
plane of the lens so that the rings and the lens can snugly fit into the 
eye chamber without causing any spring back or buldging forward which 
would injure delicate eye tissue. 
Although centration holes are normally provided on such lenses, the lens of 
this invention can dispense with such holes because with the ring 
structure and the tangentially shaped resilient strands, the right is self 
centerable. 
In FIG. 5, there is shown the implantation of this novel lens into an 
anterior chamber of an eye. The snag resistant free end of the tangential 
strand fits snugly in the corners between the mobile zone of the iris 26 
and the cornea 27. In this instance, the lens is again self centering 
because of the same factors present in the posterior implantation. 
Because of the ring shaped free end it is possible to use this lens for the 
first time to measure the size of the eye chamber. 
In FIG. 6, there is shown a schematic illustration of how to measure the 
size of an eye chamber. In (a) there is shown the lens of this invention 
having a lens body whose diameter is 6 mm and whose ring diameter is 2.5 
mm. In (b) such a lens is implanted in an eye chamber 33. The distance 
between the loop and the lens edge is measured to be 1 mm. When added 
together, it measures a 13 mm eye chamber size which is a large chamber 
size. In (c), wherein the ring to lens distance is less, a 12 mm eye 
chamber is measured which is a medium chamber size. In (d), wherein the 
ring and lens edges meet, the eye chamber measures 11 mm which is a small 
chamber size. To aid in sighting for measuring, it is helpful to slightly 
tint the snag resistant rings, however they could also be clear. 
To sum up, there are many advantages in using the lens of this invention 
over any of the prior art lenses. 
The most important advantage is the provision of a snag resistant loop 
which prevents injury to delicate eye tissue during implantation, 
centration, or removal of the lens. 
The lens of the Shearing type requires more maneuvers, skill and a longer 
learning process for surgeons to master when inserting the superior loop 
of the lens, thus resulting in increasing the chance for injuring delicate 
eye tissue. These objections are eliminated when the snag resistant lens 
of this invention is used. It would be relatively easy for a surgeon to 
master the implantation, centration or removal of this lens without injury 
to delicate eye tissue. 
Another advantage is that only a small force is needed by the surgeon to 
position the superior snag resistant ring during implantation. The 
tangentially curved resilient strands and the snag free loose end of the 
strand transfers this force into a circular movement of the lens body 
resulting in self centering of the lens with avoidance of undue pressure 
on the zonules below. 
Since the lens of the invention is one that is a universal lens, a surgeon 
who is a novitiate will find this lens especially helpful because this 
lens is not only self-centering but also needs only minimal manipulation 
during implantation in an eye chamber. 
Implantation of this new lens avoids the spring back which is present in 
the Shearing type lens which results in decentration. This lens, because 
of its tangentially formed strands, changes the downward force into a 
circular motion, thus avoiding any spring back landing to cause 
decentration. 
All conventional posterior lenses are more easily implanted through a 
dilated pupil. The new snag free lens can be implanted through a dilated 
or a miotic pupil with equal ease. 
If during a cataract operation, the delicate tissue of an eye is ruptured, 
use of the Shearing type lens with its free pointed end presents added 
danger of extending the tear because the free pointed end can slide 
further into the vitreous cavity. The snag resistant ring of this new lens 
avoids this difficulty. 
In addition, while operating to be safe, the surgeon may decide to use this 
lens in the anterior chamber to avoid aborting the implantation procedure. 
This cannot be done with any of the prior art lenses. However, it can be 
done if the surgeon is using the lens of this invention. 
The lens of this invention is the first universal lens implant since it can 
be implanted in any size of eye chamber, in a posterior chamber or in an 
anterior chamber. A tremendous saving in the stocking of an unduly large 
supply of lenses for surgeons and hospitals. Only the snag resistant lens 
of this invention need be stocked. No necessity now to stock many 
different sizes, a posterior lens and an anterior lens. All the different 
lenses have now been replaced with only one lens, a universally useful 
lens. 
Finally, this novel lens can be used to determine the size of an eye 
chamber. This has never been possible before this lens. By merely 
measuring the distance between the edge of the loop and the edge of the 
lens with a microscopic chronometer and adding thereto the diameter of the 
ring and lens, the size of an eye chamber can be determined. No lens in 
the prior art is capable of effecting this result. 
Those skilled in the art will also readily appreciate that there are 
various other modifications and adaptations of the precise form of the 
lens herein shown. For example, the ring which is approximately circular, 
could also be elliptical and would thus be equally useful with all the 
accompanying advantages so long as it is snag resistant.