Method for obtaining contact lenses with dynamically controlled sagitta and clearance
The disclosure generally describes methods, systems and products relating to the development and manufacture of scleral contact lenses. A number of dimensions for the scleral lens is generated based on control points and attendant curvature parameters. Any change to one or more of the curve parameters imparts an improved anterior and posterior surface of the scleral lens and associated thickness, while undesired modifications to control points and other curve parameters remain static inasmuch as the sagittal depth component is an input parameter of the present disclosure.
1. A system for customizing at least one scleral contact lens at one or more desired sites without altering the at least one scleral contact lens at undesired sites, the system comprising;
(a) at least one predicate lens to function as a reference for determining one or more control point sites of the predicate lens that require adjusting;
(b) at least one scleral contact lens substrate for forming an adjusted scleral contact lens;
(c) a device for altering one or more segment parameters of the at least one scleral contact lens substrate requiring adjustment relative to the predicate lens, wherein each of the one or more segment parameters comprise components selected from the group consisting of at least one sagittal component, at least one radius component, and at least one chord diameter component, and wherein the device is computer-guided and configured to alter the one or more segment parameters such that a change in one or more of the components for each of the one or more segment parameters is associated with a corresponding change at the one or more control point sites, and further wherein the device is computer-guided and configured such that changes to any single segment parameter modify the at least one scleral contact lens substrate at the desired control point site of the one or more control point sites and do not modify the at least one sclera’ contact lens substrate at undesired control point sites of the one or more control point sites, wherein
the device is further configured for forming at least one customized scleral contact lens by the device from the at least one scleral contact lens substrate that has been adjusted in accordance with the one or more altered segment parameters;
wherein the device comprises a lathe with a cutting tool;
wherein the predicate scleral contact lens has a surface comprising a base curve segment positioned in a central portion of the lens, a dynamic curve segment peripherally surrounding the base curve segment, a limbal clearance curve segment peripherally surrounding the dynamic curve segment, and a peripheral curve segment peripherally surrounding the limbal clearance curve segment, wherein the base curve segment is defined by segment parameter components comprising a base curve sagittal component SA, a base curve radius component RA, and a base curve chord diameter component DA, the dynamic curve segment is defined by segment parameter components comprising a dynamic curve sagittal component SB, a dynamic curve radius component RB, and a dynamic curve chord diameter component DB, the limbal clearance curve segment is defined by segment parameter components comprising a limbal clearance curve sagittal component SC, a limbal clearance curve radius component RC, and a limbal clearance curve chord diameter component DC, the peripheral curve segment is defined by segment parameter components comprising a peripheral curve sagittal component SD, a peripheral curve radius component RD, and a peripheral curve chord diameter component DD, and the lens has a total sagittal clearance ST, and the sagittal component of a dynamic curve is an input parameter for the lathe based on an algorithm defined by:
Notation
Parameter
Formula/Calculation
(SA)
Base Curve
=RA − sqrt(RA{circumflex over ( )}2 − (DA/2){circumflex over ( )}2)
(SC)
Limbal
Clearance
=RC − sqrt(RC{circumflex over ( )}2 − (DC/2){circumflex over ( )}2) − RC −
Curve
sqrt(RC{circumflex over ( )}2 − (DB/2){circumflex over ( )}2)
(SD)
Peripheral
Curve
=RD − sqrt(RD{circumflex over ( )}2 − DD/2){circumflex over ( )}2) − RD −
(SB)
Dynamic
sqrt(RC{circumflex over ( )}2 − (DC/2){circumflex over ( )}2)
Curve
Sagittal
=Stotal − SD − SC − SA
Component
(RB)
Dynamic
=SQRT((((DA/2){circumflex over ( )}2) + ((((((DB/2){circumflex over ( )}2) −
Curve Radius
((DA/2){circumflex over ( )}2) + (SB{circumflex over ( )}2))/(2*SB)){circumflex over ( )}2))).
2. A system for customizing at least one sacral contact lens at one or more desired sites without altering the at least one scleral contact lens at undesired sites, the system comprising:
(a) at least one predicate lens to function as a reference for determining, one or more control point sites of the predicate lens that require adjusting;
(b) at least one scleral contact lens substrate for forming an adjusted scleral contact lens;
(c) a device for altering one or more segment parameters of the at least one scleral contact lens substrate requiring adjustment relative to the predicate lens, wherein each of the one or more segment parameters comprise components selected from the group consisting of at least one sagittal component, at least one radius component and at least one chord diameter component, and wherein the device is computer-guided and configured to alter the one or more segment parameters such that a change in one or more of the components for each of the one or more segment parameters is associated with a corresponding change at the one or more control point sites, and further wherein the device is computer-guided and configured such that changes to any single segment parameter modify the at least one scleral contact lens substrate at the desired control point site of the one or more control point sites and do not modify the at, least one scleral contact lens substrate at undesired control point sites of the one or more control point sites, wherein
the device is further configured for forming at least one customized scleral contact lens by the device from the at least one scleral contact lens substrate that has been adjusted in accordance with the one or more altered segment parameters;
wherein the predicate scleral contact lens has a surface comprising a base curve segment positioned in a central portion of the lens, a dynamic curve segment peripherally surrounding the base curve segment, a limbal clearance curve segment peripherally surrounding the dynamic curve segment, and a peripheral curve segment peripherally surrounding the limbal clearance curve segment, wherein the base curve segment is defined by segment parameter components comprising a base curve sagittal component SA, a base curve radius component RA, and a base curve chord diameter component DA, the dynamic curve segment is defined by segment parameter components comprising a dynamic curve sagittal component SB, a dynamic curve radius component RB, and a dynamic curve chord diameter component DB, the limbal clearance curve segment is defined by segment parameter components comprising a limbal clearance curve sagittal component SC, a limbal clearance curve radius component RC, and limbal clearance curve chord diameter component DC, the peripheral curve segment is defined by segment parameter components comprising a peripheral curve sagittal component SD, a peripheral curve radius component RD, and a peripheral curve chord diameter component DD, and the lens has a total sagittal clearance ST;
and wherein the device is configured for selection of one or more control points selected from a central vault clearance, a mid-peripheral clearance, and a limbal clearance of the predicate contact lens that for adjustment, and one or more of such control points that are not to be adjusted, for forming the scleral contact lens to be manufactured having a surface corresponding to altered segment parameters relative to the predicate lens in accordance with a computer implemented algorithm on computer readable media; and wherein the device is further configured for altering one or more segment parameters of the predicate lens selected from the group consisting of the base curve segment, the dynamic curve segment, and the limbal clearance curve segment for adjusting each of the control points to be adjusted, wherein a change in one or more at the components for each of the one or more segment parameters is associated with a corresponding change in the one or more control points to be adjusted, and further wherein changes to arty single segment parameter modify the contact lens at a control point to be adjusted of the one or more control points and do not modify the contact lens at control points not to be adjusted of the one or more control points, wherein (i) a change in the central vault clearance control point corresponds to changes to the dynamic curve sagittal component and to the total sagittal clearance of the lens, (ii) a change in the mid-peripheral clearance control point corresponds to changes to the dynamic curve sagittal component and to the base curve sagittal component, and (iii) a change in the limbal clearance control point corresponds to changes to the dynamic curve sagittal component and the limbal sagittal component.
3. The system of claim 2 , wherein the device is configured such that each of the base curve radius component, the dynamic curve radius component, and the limbal clearance curve radius component represent radii of curvature for arcs with respect to a central optical axis of the contact lens, and is further configured to perform at least one of (iv)-(vi):
(iv) based on a specification of aril adjustment to the total sagittal clearance of the predicate lens, changes to the dynamic curve sagittal component and dynamic curve radius component of the predicate lens are calculated to effect changes in the central vault clearance control point of the lens to be manufactured, in accordance with the algorithms
ST 1=Specified
SB 1= ST 1− SA−SC
and
RB 1=SQRT((( DA/ 2)∧2)+(((((( DB/ 2)∧2)−(( DA/ 2)∧2)+( SB 1∧2))/(2* SB 1))∧2))),
wherein ST1 is the specified adjusted total sagittal clearance, SB1 is the calculated changed dynamic curve sagittal component, and RB1 is the calculated changed dynamic curve radius component,
(v) based on a specification of an adjustment to the base curve radius of the predicate lens and changes to the dynamic curve sagittal component, the dynamic curve radius component and the base curve sagittal component of the predicate lens are calculated to effect changes in the mid-peripheral clearance control point of the lens to be manufactured, in accordance with the algorithms
RA 2=Specified
SA 2= RA 2−sqrt( RA 2∧2− DA/ 2)∧2)
SB 2= ST−SA 2− SC
and
RB 2=SQRT((( DA/ 2)∧2)+(((((( DB/ 2)∧2)−(( DA/ 2)∧2)+( SB 2∧2))/(2* SB 2))∧2))),
wherein RA2 is the specified adjusted base curve radius, SA2 is the calculated changed base curve sagittal component, SB2 is the calculated Changed dynamic curve sagittal component, and RB2 is the calculated changed dynamic curve radius component, and
(vi) based on a specification of an adjustment to the limbal clearance curve radius of the predicate lens and changes to the dynamic curve sagittal component, the dynamic curve radius component and the limbal clearance curve sagittal component of the predicate lens are calculated to effect changes in the limbal clearance control point of the lens to be manufactured, in accordance with the algorithms
RC 3=Specified
SC 3= RC 3−sqrt( RC 3∧2−( DC/ 2)∧2− RC 3−sqrt( RC 3∧2−( DB/ 2)∧2)
SB 3= ST−SA−SC 3
and
RB 3=SQRT((( DA/ 2)∧2)+(((((( DB/ 2)∧2)−(( DA/ 2)∧2)+ SB 3∧2))/(2* SB 3))∧2))),
wherein RC3 is the specified adjusted limbal clearance curve radius, SC3 is the calculated changed limbal clearance curve sagittal component, SB3 is the calculated changed dynamic curve sagittal component, and RB3 is the calculated changed dynamic curve radius component.
4. The system of claim 3 , wherein the device is configured to perform (iv).
5. The system of claim 3 , wherein the device is configured to perform (v).
6. The system of claim 3 , wherein the device is configured to perform (vi).
7. The system of claim 2 , wherein the device is further configured for adjusting a scleral alignment angle of the lens to be manufactured relative to the predicate lens by adjusting one or more component of the peripheral curve segment of the predicate lens.
8. The system of claim 2 , wherein the device is configured such that the sagittal component of the base curve, the dynamic curve and the limbal clearance curve comprise the total sagittal clearance for the contact lens.
9. The system of claim 2 , wherein the device is configured such that the base curve, dynamic curve, limbal clearance curve and peripheral curve are segment parameters for a spherical curve.
10. The system of claim 2 , wherein the device is configured such that at least one of the base curve, dynamic curve, limbal clearance curve and peripheral curve are segment parameters for an aspheric curve.
11. The system of claim 10 , wherein the device is configured such that the aspheric curve is selected from the group consisting of conical sections, polynomials, splines, straight lines, angled lines, tapered lines, polygonal curves, rectangular, square, circular, diagonal, concentric, patterned, perimetric, hexagonal, or triangular configurations, or any free form line possessing a start point, an end point, and connects two defined points in space, and/or other shapes that are congruent for use as a sagittal component.
12. The system of claim 2 , wherein the device is further configured to define one or more additional segment parameter curves anchor one or more additional control points selected from the group consisting of one or more curves and/or sagittal components, wherein all the curves and/or sagittal components are defined for the contact lens other than the dynamic curve sagittal component, and wherein the dynamic curve sagittal component is calculated to achieve a desired total sagittal clearance.
13. The system of claim 12 , wherein the one or more additional segment parameter curves are selected from the group consisting of one or more additional base curves, dynamic curves, limbal clearance curves and peripheral curves, and combinations thereof.
14. A system for customizing at least one sacral contact lens at one or more desired sites without altering the at least one scleral contact lens at undesired sites, the system comprising:
(a) at least one predicate lens to function as a reference for determining one or more control point sites of the predicate lens that require adjusting;
(b) at least one scleral contact lens substrate for forming an adjusted scleral contact lens;
(c) a device for altering one or more segment parameters of the at least one scleral contact lens substrate requiring adjustment relative to the predicate lens, wherein each of the one or more segment parameters comprise components selected from the group consisting of at least one sagittal component, at least one radius component, and at least one chord diameter component, and wherein the device is computer-guided and configured to alter the one or more segment parameters such that a change in one or more of the components for each of the one or more segment parameters is associated with a corresponding change at the one or more control point sites, and further wherein the device is computer-guided and configured such that changes to any single segment parameter modify the at least one scleral contact lens substrate at the desired control point site of the one or more control point sites and do not modify the at least one scleral contact lens substrate at undesired control point sites of the one or more control point sites, wherein
the device is further configured for forming at least one customized scleral contact lens by the device from the at least one scleral contact lens substrate that has been adjusted in accordance with the one or more altered segment parameters;
wherein the device is configured such that one or more control points may be adjusted by, altering the segment parameters and wherein the segment parameters are selected from the group consisting of base curve, dynamic curve, limbal clearance curve and peripheral curve, and combinations thereof; and
wherein the device is configured such that changes to the sagittal component of the peripheral curve do not impact the total sagittal clearance.
15. A system for customizing at least one sacral contact lens at one or more desired sites without altering the at least one scleral contact lens at undesired sites, the system comprising:
(a) at least one predicate lens to function as a reference for determining one or more control point sites of the predicate lens that require adjusting:
(b) at least one scleral contact lens substrate for forming an adjusted scleral contact lens:
(c) a device for altering one or more segment parameters of the at least one scleral contact lens substrate requiring adjustment relative to the predicate lens, wherein each of the one or more segment parameters comprise components selected from the group consisting of at least one sagittal component, at least one radius component, and at least one chord diameter component, and wherein the device is computer-guided and configured to alter the one or more segment parameters such that a change in one or more of the components for each of the one or more segment parameters is associated with a corresponding change at the one or more control point sites, and further wherein the device is computer-guided and configured such that changes to any single segment parameter modify the at least one scleral contact lens substrate at the desired control point site of the one or more control point sites and do not modify the at least one scleral contact lens substrate at undesired control point sites of the one or more control point sites, wherein
the device is further configured for forming at least one customized scleral contact lens by the device from the at least one scleral contact lens substrate that has been adjusted in accordance with the one or more altered segment parameters;
wherein the device is configured such that one or more control points may be adjusted by altering the segment parameters, and wherein the segment parameters are selected from the group consisting of base curve, dynamic curve, limbal clearance curve and peripheral curve, and combinations thereof; and
wherein the device is configured such that changes to the peripheral curve correspond to changes in the scleral alignment angle control point.