WO2020128817A1 - Method for managing the dynamic displacement of a contact lens placed on an eye - Google Patents

Method for managing the dynamic displacement of a contact lens placed on an eye Download PDF

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Publication number
WO2020128817A1
WO2020128817A1 PCT/IB2019/060900 IB2019060900W WO2020128817A1 WO 2020128817 A1 WO2020128817 A1 WO 2020128817A1 IB 2019060900 W IB2019060900 W IB 2019060900W WO 2020128817 A1 WO2020128817 A1 WO 2020128817A1
Authority
WO
WIPO (PCT)
Prior art keywords
curvature
quadrant
flange
radius
contact lens
Prior art date
Application number
PCT/IB2019/060900
Other languages
French (fr)
Inventor
Mauro Costantino FIRINAIU
Original Assignee
Firinaiu Mauro Costantino
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Firinaiu Mauro Costantino filed Critical Firinaiu Mauro Costantino
Priority to EP19839265.6A priority Critical patent/EP3899651A1/en
Publication of WO2020128817A1 publication Critical patent/WO2020128817A1/en

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
    • G02C7/00—Optical parts
    • G02C7/02—Lenses; Lens systems ; Methods of designing lenses
    • G02C7/04—Contact lenses for the eyes
    • G02C7/047—Contact lens fitting; Contact lenses for orthokeratology; Contact lenses for specially shaped corneae

Definitions

  • This invention refers to a method for managing the dynamic displacement of a contact lens placed on an eye.
  • the contact lens which has a concave shape in the rear surface and a convex shape in the front surface, is made with an internal geometry having the same curvature radii of the cornea.
  • the contact lens consists internally of an optical zone, flanges and an edge.
  • the optical zone corresponds to the lens portion through which the optical correction takes place.
  • the flanges are the secondary curves or the lens areas that begin immediately after the end of the optical zone in the inner surface of the lens and arrive rising from the cornea to the edge of the lens.
  • the lenses are not centered correctly on the cornea owing to the following reasons: the corneal conformation, the balance of the weights of the lens, the quality and quantity of the tear film, the thrust impressed on the lens by the action of the eyelids, etc.
  • the contact lens becomes decentralized upwards and downwards, according to a vertical axis, and specifically, if during the application of the lens, the lens tilts being decentralized upwards, it is possible to reposition the lens downwards by tightening the curvature of the lens. In the lens with the more closed curvature, the resultant of the forces involved is moved back, that is, towards the retina. In this way, the dynamics of the lens is modified and the lens is repositioned and tilted lower.
  • the contact lens becomes decentralized upwards or downwards, according to a vertical axis, and specifically, if during the application of the lens, the lens tilts being decentralized downwards, it is possible to reposition the lens upwards by opening the curvature of the lens. In the lens with a more open curvature, the resultant of the forces involved is moved forward towards the cornea. In this way, the dynamics of the lens is modified and the lens is repositioned and tilted higher.
  • the contact lens becomes decentralized towards the nose or temples, according to a horizontal axis, it is possible to increase the optical zone or the diameters of the flanges to re-center the lenses that do not stabilize well on the center of the pupil or are not positioned correctly on the cornea.
  • the push of the eyelids and the conformation of the sclera in the nasal area which is more open or, rather, has wider radii of curvature, tend to decentralize, on the temporo- nasal line, the contact lens towards the temple.
  • the aforesaid method is carried out in an empirical way or with the support of new digital mapping systems for the digital mapping of the sclera but without any centering management of the internal optical zone.
  • the curves of the flanges are opened in the various zones not only to better unload the weights of the contact lens but also to avoid the formation of closures to the dynamics of the tear film, or narrowings in the conjunctival vessels where the lens is places.
  • This system is applied to all the lenses but in particular to the contact lenses that are gas-permeable (hard) and have a great diameter: corneal, semi-scleral and scleral contact lenses.
  • the object and function of the present invention is to remove the above- mentioned inconveniences and still others by providing a method that allows to control and manage the dynamic displacement of the geometry of the internal optical zone of a contact lens.
  • the method according to the invention allows to control and manage the dynamic displacement of a contact lens placed on an eye, by modifying and displacing the temporo-nasal/high-low dynamics of the internal/external geometries for a precise control of the centering of the geometries, which is in particular useful for the multifocal or progressive lenses.
  • the management of the displacement of the lens centering is carried out through the displacement of the resulting forces by modifying, in the internal surface of the lens, the flanges (secondary curves) divided into quadrants.
  • the internal surface of the lens is made up by the optical zone, the flanges (secondary curves), which can be single or multiple, spherical or aspherical, and the edge.
  • Figure 1 is a schematic front view of a contact lens according to the invention, in a use phase on an eye;
  • Figure 2 is a schematic front view of the contact lens in Figure 1.
  • reference number 10 denotes a contact lens that can be applied to an eye and precisely, on the cornea C between the pupil and the eyelids, in particular the upper eyelid Ps and the lower eyelid Pi.
  • the perfectly circular contact lens 10 is placed on the right eye (with respect to the position of the nose N) and has a slightly greater diameter than the cornea C.
  • the contact lens 10 includes an optical zone 12, a perimeter flange 14 and a perimeter edge 16.
  • the perimeter edge 16 is around the edge B that separates the cornea C from the sclera S.
  • the flange 14 has such a curvature that it allows to block the contact lens 10 in the desired position.
  • the perimeter flange 14 is divided into four quadrants by two orthogonal axes that are arranged at 45° with respect to a horizontal axis.
  • the four quadrants are a temple quadrant 18, an upper quadrant 20, a nasal quadrant 22 and a lower quadrant 24.
  • the contact lens 10 is moved towards the temple and vice versa, by decreasing the curvature of the temple quadrant 18, the contact lens 10 is moved towards the nose.
  • the contact lens 10 is moved towards the eye and vice versa, by decreasing the curvature of the nasal quadrant 22, the contact lens 10 is moved towards the temple.
  • the contact lens 10 is moved downwards and vice versa, by decreasing the curvature of the lower quadrant 24, the contact lens 10 is moved upwards. It should be noted that a correct centering of the lens can be obtained by simultaneously managing the curvature of all four quadrants of the flange.
  • This method allows not only to shift the lens balance through the management of the radii of curvature of the flange divided into quadrants to position the lens with a complete and precise control of the displacement, but also to generate few tensions on the material in the optical zone and creates the advantage of not stressing the surface and avoiding to bring modifications or alterations to the geometries of the external optical zone.
  • the method according to the invention has been described for the correct centering of a contact lens 10 when applied to a contact lens 10 for a right eye, but obviously, this method can be applied also to a contact lens for a left eye.
  • the flange can be divided into a number of portions different from the aforesaid four quadrants, for example six or eight or more portions of equal size.
  • a contact lens can have also two or more flanges along its perimeter, all said flanges can be divided into quadrants as described above in the case of a single flange, so as to further improve the accuracy of the contact lens position.

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  • Health & Medical Sciences (AREA)
  • Ophthalmology & Optometry (AREA)
  • Physics & Mathematics (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Eyeglasses (AREA)

Abstract

It refers to a method for managing the dynamic displacement of a contact lens placed on an eye.

Description

METHOD FOR MANAGING THE DYNAMIC DISPLACEMENT OF A CONTACT
LENS PLACED ON AN EYE
Description
This invention refers to a method for managing the dynamic displacement of a contact lens placed on an eye.
The contact lens, which has a concave shape in the rear surface and a convex shape in the front surface, is made with an internal geometry having the same curvature radii of the cornea. The contact lens consists internally of an optical zone, flanges and an edge.
The optical zone corresponds to the lens portion through which the optical correction takes place.
The flanges are the secondary curves or the lens areas that begin immediately after the end of the optical zone in the inner surface of the lens and arrive rising from the cornea to the edge of the lens.
Despite the precision in the construction of the curves of the lenses, unexpected behaviors of dynamics occur. The lenses are not centered correctly on the cornea owing to the following reasons: the corneal conformation, the balance of the weights of the lens, the quality and quantity of the tear film, the thrust impressed on the lens by the action of the eyelids, etc.
Thus, dynamic displacements of the lens take place when the lens is placed on the cornea. These dynamic displacements of the lens are managed in various ways.
In case the contact lens becomes decentralized upwards and downwards, according to a vertical axis, and specifically, if during the application of the lens, the lens tilts being decentralized upwards, it is possible to reposition the lens downwards by tightening the curvature of the lens. In the lens with the more closed curvature, the resultant of the forces involved is moved back, that is, towards the retina. In this way, the dynamics of the lens is modified and the lens is repositioned and tilted lower.
In case the contact lens becomes decentralized upwards or downwards, according to a vertical axis, and specifically, if during the application of the lens, the lens tilts being decentralized downwards, it is possible to reposition the lens upwards by opening the curvature of the lens. In the lens with a more open curvature, the resultant of the forces involved is moved forward towards the cornea. In this way, the dynamics of the lens is modified and the lens is repositioned and tilted higher.
In case the contact lens becomes decentralized towards the nose or temples, according to a horizontal axis, it is possible to increase the optical zone or the diameters of the flanges to re-center the lenses that do not stabilize well on the center of the pupil or are not positioned correctly on the cornea. The push of the eyelids and the conformation of the sclera in the nasal area, which is more open or, rather, has wider radii of curvature, tend to decentralize, on the temporo- nasal line, the contact lens towards the temple.
However, to date none of the operating systems allows to control the dynamics of the lenses so as to center with precision the internal optical zone on the cornea.
It is always necessary to decide whether to increase or decrease the radii of curvature or the diameters of the contact lenses in order to try to find the best solution but it is never possible to have a full control of the centering. The changes that are made concern the flanges in the rigid semi-scleral and scleral contact lenses (the characteristic of these lenses is that these lenses are placed on the sclera on which the weight of the lens is unloaded and form an arch on the cornea) with the intent to uniformly unload the weights deriving from the weight of the lens and the pushing action of the eyelids on the sclera.
The aforesaid method is carried out in an empirical way or with the support of new digital mapping systems for the digital mapping of the sclera but without any centering management of the internal optical zone.
In some cases, the curves of the flanges are opened in the various zones not only to better unload the weights of the contact lens but also to avoid the formation of closures to the dynamics of the tear film, or narrowings in the conjunctival vessels where the lens is places. This system is applied to all the lenses but in particular to the contact lenses that are gas-permeable (hard) and have a great diameter: corneal, semi-scleral and scleral contact lenses.
The object and function of the present invention is to remove the above- mentioned inconveniences and still others by providing a method that allows to control and manage the dynamic displacement of the geometry of the internal optical zone of a contact lens.
All said objects and advantages are achieved according to the invention through a method as claimed.
The method according to the invention allows to control and manage the dynamic displacement of a contact lens placed on an eye, by modifying and displacing the temporo-nasal/high-low dynamics of the internal/external geometries for a precise control of the centering of the geometries, which is in particular useful for the multifocal or progressive lenses.
In other words, the management of the displacement of the lens centering is carried out through the displacement of the resulting forces by modifying, in the internal surface of the lens, the flanges (secondary curves) divided into quadrants.
In fact, the internal surface of the lens is made up by the optical zone, the flanges (secondary curves), which can be single or multiple, spherical or aspherical, and the edge.
With the modification of the curvature of the flanges per quadrant, it happens that the lens is pushed in the opposite direction to the applied force. By tightening the radius or radii of curvature of the flange in a quadrant, a greater thrust is applied in the zone of the flange to the cornea and the lens is moved in the opposite direction.
Further features and details of the invention can be better understood from the following specification that is supplied by way of a non-limiting example as well as from the annexed drawing, wherein:
Figure 1 is a schematic front view of a contact lens according to the invention, in a use phase on an eye;
Figure 2 is a schematic front view of the contact lens in Figure 1.
With reference to Figures 1 and 2, reference number 10 denotes a contact lens that can be applied to an eye and precisely, on the cornea C between the pupil and the eyelids, in particular the upper eyelid Ps and the lower eyelid Pi.
As shown in Figure 1 , the perfectly circular contact lens 10 is placed on the right eye (with respect to the position of the nose N) and has a slightly greater diameter than the cornea C.
In particular, the contact lens 10 includes an optical zone 12, a perimeter flange 14 and a perimeter edge 16.
The perimeter edge 16 is around the edge B that separates the cornea C from the sclera S.
The flange 14 has such a curvature that it allows to block the contact lens 10 in the desired position.
In particular, depending on the curvature of a portion of the flange 14 it is possible to shift the contact lens 10 forward or backward on an axis orthogonal to the portion of the flange 14.
For a lens management convenience, the perimeter flange 14 is divided into four quadrants by two orthogonal axes that are arranged at 45° with respect to a horizontal axis.
The four quadrants are a temple quadrant 18, an upper quadrant 20, a nasal quadrant 22 and a lower quadrant 24.
Consequently, by increasing the curvature of the temple quadrant 18, the contact lens 10 is moved towards the temple and vice versa, by decreasing the curvature of the temple quadrant 18, the contact lens 10 is moved towards the nose.
Likewise, by increasing the curvature of the nasal quadrant 22, the contact lens 10 is moved towards the eye and vice versa, by decreasing the curvature of the nasal quadrant 22, the contact lens 10 is moved towards the temple.
Concerning the other two quadrants 20, 24, by increasing the curvature of the upper quadrant 20, the contact lens 10 is moved upwards and vice versa, by decreasing the curvature of the upper quadrant 20, the contact lens 10 is moved downwards.
Likewise, by increasing the curvature of the lower quadrant 24, the contact lens 10 is moved downwards and vice versa, by decreasing the curvature of the lower quadrant 24, the contact lens 10 is moved upwards. It should be noted that a correct centering of the lens can be obtained by simultaneously managing the curvature of all four quadrants of the flange.
Thus, in case the contact lens 10 in situ remains decentralized towards the temple, it is possible to make three adjustments:
1 . increasing the radius of curvature of the flange in the nasal quadrant 22;
2. increasing the radius of curvature of the flange in the nasal quadrant 22 and at the same time, decreasing the radius of curvature of the flange in the temple quadrant 18;
3. decreasing the radius of curvature of the flange in the temple quadrant 18.
In essence, it is necessary to generate or lighten the thrusts that are capable to modify the positioning of the applied lens.
Likewise, in case the contact lens in situ is decentralized nasally, it is possible to make three different modifications to the contact lens:
1. increasing the radius of curvature of the flange 14 in the temple quadrant 18;
2. increasing the radius of curvature of the flange 14 in the temple quadrant 18 and at the same time, decreasing the radius of curvature in the nasal quadrant 22;
3. decreasing the radius of curvature of the flange 14 in the nasal quadrant 22.
In case the lens in situ is decentralized upwards, it is possible alternatively:
1. decreasing the radius of curvature of the flange 14 in the upper quadrant
20;
2. decreasing the radius of curvature of the flange 14 in the upper quadrant 20 and increasing the radius of curvature of the flange 14 in the lower quadrant
24; 3. increasing the radius of curvature of the flange in the lower quadrant 24.
In case the lens in situ is decentralized downwards, it is possible alternatively:
1. decreasing the radius of curvature of the flange 14 in the lower quadrant 24; 2. decreasing the radius of curvature of the flange 14 in the lower quadrant 24 and increasing the radius of curvature of the flange in the upper quadrant 22
3. increasing the radius of curvature of the flange 14 in the upper quadrant 22.
This method allows not only to shift the lens balance through the management of the radii of curvature of the flange divided into quadrants to position the lens with a complete and precise control of the displacement, but also to generate few tensions on the material in the optical zone and creates the advantage of not stressing the surface and avoiding to bring modifications or alterations to the geometries of the external optical zone.
In fact, it is important not to alter the external geometries so as not to alter the foci that reach the retina especially in multifocal or progressive geometries.
The method according to the invention has been described for the correct centering of a contact lens 10 when applied to a contact lens 10 for a right eye, but obviously, this method can be applied also to a contact lens for a left eye.
Variants are possible to be considered as included in the scope of protection as defined by the annexed claims.
The flange can be divided into a number of portions different from the aforesaid four quadrants, for example six or eight or more portions of equal size.
Besides, since a contact lens can have also two or more flanges along its perimeter, all said flanges can be divided into quadrants as described above in the case of a single flange, so as to further improve the accuracy of the contact lens position.
In this way, it is possible to change the angle of curvature for each quadrant of each flange of the contact lens.

Claims

1. Method for centering a contact lens (10) to be applied on the cornea C of an eye, and including a focal area (12), a perimeter flange (14) and a perimeter edge (16), wherein the flange (14) is curved according to a radius of curvature in order to retain the contact lens (10) in position with respect to the eye, characterized by the fact of comprising the following steps:
- dividing the flange (14) into at least four portions (18, 20, 22, 24), each of said four portions having a respective radius of curvature;
- increasing or decreasing the radius of curvature of at least one of said four portions (18, 20, 22, 24).
2. Method according to the preceding claim, wherein the four portions of the contact lens (10) include a temple quadrant (18), an upper quadrant (20), a nasal quadrant (22) and a lower quadrant (24).
3. Method according to the preceding claim, wherein by increasing or decreasing the curvature of the temple quadrant (18), the contact lens (10) is moved towards the temple or towards the nose, respectively.
4. Method according to claims 2 or 3, wherein by increasing or decreasing the curvature of the nasal quadrant (22), the contact lens (10) is moved towards the nose or towards the temple, respectively.
5. Method according to one of claims 2 to 4, wherein by increasing or decreasing the curvature of the upper quadrant (20), the contact lens (10) is moved upwards or downwards, respectively.
6. Method according to one of claims 2 to 5, wherein by increasing or decreasing the curvature of the lower quadrant (24), the contact lens (10) is moved downwards or upwards, respectively.
7. Method according to one of claims 2 to 6, wherein in case the contact lens (10) positioned on the eye is decentralized towards the temple, it is possible to make three alternative adjustments:
- increasing the radius of curvature of the flange in the nasal quadrant (22); - increasing the radius of curvature of the flange in the nasal quadrant (22) and at the same time, decreasing the radius of curvature of the flange in the temple quadrant (18);
- decreasing the radius of curvature of the flange in the temple quadrant (18).
8. Method according to one of claims 2 to 7, wherein in case the contact lens (10) positioned on the eye is nasally decentralized, it is possible to make three alternative adjustments:
- increasing the radius of curvature of the flange (14) in the temple quadrant (18);
- increasing the radius of curvature of the flange (14) in the temple quadrant (18) and at the same time, decreasing the radius of curvature in the nasal quadrant (22);
- decreasing the radius of curvature of the flange (14) in the nasal quadrant
(22).
9. Method according to one of claims 2 to 8, wherein in case the contact lens (10) positioned on the eye is decentralized upwards, it is possible to make three alternative adjustments:
- decreasing the radius of curvature of the flange (14) in the upper quadrant
(20);
- decreasing the radius of curvature of the flange (14) in the upper quadrant (20) and increasing the radius of curvature of the flange (14) in the lower quadrant (24);
- increasing the radius of curvature of the flange in the lower quadrant (24). 10. Method according to one of claims 2 to 9, wherein in case the contact lens (10) positioned on the eye is decentralized downwards, it is possible to make three alternative adjustments:
- decreasing the radius of curvature of the flange (14) in the lower quadrant (24);
- decreasing the radius of curvature of the flange (14) in the lower quadrant (24) and increasing the radius of curvature of the flange in the upper quadrant (22);
- increasing the radius of curvature of the flange (14) in the upper quadrant (22).
PCT/IB2019/060900 2018-12-17 2019-12-17 Method for managing the dynamic displacement of a contact lens placed on an eye WO2020128817A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP19839265.6A EP3899651A1 (en) 2018-12-17 2019-12-17 Method for managing the dynamic displacement of a contact lens placed on an eye

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT102018000011177A IT201800011177A1 (en) 2018-12-17 2018-12-17 Method for managing the dynamic displacement of a contact lens placed on an eye
IT102018000011177 2018-12-17

Publications (1)

Publication Number Publication Date
WO2020128817A1 true WO2020128817A1 (en) 2020-06-25

Family

ID=66218293

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2019/060900 WO2020128817A1 (en) 2018-12-17 2019-12-17 Method for managing the dynamic displacement of a contact lens placed on an eye

Country Status (3)

Country Link
EP (1) EP3899651A1 (en)
IT (1) IT201800011177A1 (en)
WO (1) WO2020128817A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070091259A1 (en) * 2005-10-25 2007-04-26 Svochak Jan B Contact lens with controlled shape
WO2007066666A1 (en) * 2005-12-05 2007-06-14 Menicon Co., Ltd. Soft contact lens
EP2876486A1 (en) * 2012-07-18 2015-05-27 Menicon Co., Ltd. Contact lens and method for manufacturing contact lens
WO2017123091A1 (en) * 2016-01-15 2017-07-20 Chrétien Special Optics B.V. Method for the production of a pair of contact lenses for the improvement of the visual performance in patients with keratoconus, as well as a set of lenses

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070091259A1 (en) * 2005-10-25 2007-04-26 Svochak Jan B Contact lens with controlled shape
WO2007066666A1 (en) * 2005-12-05 2007-06-14 Menicon Co., Ltd. Soft contact lens
EP2876486A1 (en) * 2012-07-18 2015-05-27 Menicon Co., Ltd. Contact lens and method for manufacturing contact lens
WO2017123091A1 (en) * 2016-01-15 2017-07-20 Chrétien Special Optics B.V. Method for the production of a pair of contact lenses for the improvement of the visual performance in patients with keratoconus, as well as a set of lenses

Also Published As

Publication number Publication date
EP3899651A1 (en) 2021-10-27
IT201800011177A1 (en) 2020-06-17

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