# US 11,076,994 B2 · Apparatus for changing the refractive power of the cornea > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,076,994 B2 - Document ID: US11076994B2 - Status: Granted - Kind: B2 - Application number: 16/306,228 - Filed: 2017-05-31 - Published: 2019-07-11 - Granted: 2021-08-03 - Earliest claimed: 2016-05-31 - Assignees: The General Hospital Corporation - Applicants: The General Hospital Corporation - Inventors: Alfred Vogel; Norbert Linz; Sebastian Freidank; Reginald Birngruber - Web page: https://patentgrep.com/patent/US11076994B2 ## CPC - A61F 9/013: {Instruments} for compensation of ocular refraction (A61F9/008 takes precedence){; Instruments for use in cornea removal, for reshaping or performing incisions in the cornea} - A61F 2/147: {Implants to be inserted in the stroma for refractive correction, e.g. ring-like implants} - A61F 2/148: {Implantation instruments specially adapted therefor} - A61F 9/0017: {implantable in, or in contact with, the eye, e.g. ocular inserts} - A61B 3/102: {for optical coherence tomography [OCT]} - A61B 3/107: for determining the shape or measuring the curvature of the cornea - A61F 2240/002: Designing or making customized prostheses - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract The invention relates to an apparatus for changing the refractive power of the cornea (1), in particular for correcting hyperopia or presbyopia, exhibiting injection means (13, 15) having at least one hollow needle (15) for injecting at least one optically transparent filling material having a predetermined refractive index into an intrastromal corneal pocket (7), characterized by a controllable injection drive (17) that is coupled at least indirectly to the injection means (13, 15) and is designed for changing an amount, to be injected, of the at least one filling material; a device for optical coherence tomography (OCT) (19) that is designed for monitoring the area of the corneal pocket (7) by means of measurement of depth profiles of the cornea (1) on a repeatedly cycled-through scan pattern; and a computing unit (21) that is designed and/or configured to determine from the measurement data of the OCT device (19) at least the radius of curvature of the front (3) of the cornea (1) keeping pace temporally with the repetitions of the scan pattern cycle during the injection, wherein the computing unit (21) is designed and/or configured to control the injection drive (17) for changing the injected amount of the at least one filling material, and namely on the basis of the radius of curvature of the front (3) of the cornea (1) and/or such until a predetermined target criterion is fulfilled. ## Claims ### Claim 1 A system for changing a refractive power of a cornea, comprising an injection system having at least one hollow needle arranged to inject at least one optically transparent filling material having a predetermined refractive index into an intrastromal pocket in the cornea having the refractive power; a computing unit; a controllable injection drive coupled directly or indirectly to the injection system and to the computing unit, wherein the injection drive is controlled by the computing unit to adjust an amount to be injected of the at least one filling material; and a device for optical coherence tomography (OCT) arranged to monitor an area of the corneal pocket by measuring depth profiles of the cornea to produce measurement data and to transmit the measurement data to the computing unit; wherein the computing unit is arranged and configured to determine from the measurement data of the OCT device at least a radius of curvature of a front surface of the cornea, and wherein the computing unit is arranged and configured to control the injection drive to adjust an injected amount of the at least one filling material based on the radius of curvature of the front of the cornea until a predetermined first target criterion is fulfilled. ### Claim 2 (depends on 1) The system of claim 1, further comprising the optically transparent filling material, wherein the predetermined refractive index of the filling material substantially coincides with a refractive index of stromal tissue of the cornea and wherein the computing unit is arranged and configured to compute the refractive power of the cornea as that of a convex-concave lens based on at least the determined radius of curvature of the front surface of the cornea. ### Claim 3 (depends on 2) The system of claim 2, wherein the computing unit is configured to check a coincidence of the computed refractive power of the cornea with a predetermined desired value as a second target criterion. ### Claim 4 (depends on 1) The system of claim 1, wherein the computing unit is arranged and configured to determine from the measurement data of the OCT device a travel of the corneal pocket along an optical axis of the cornea and radii of curvature of front and rear limiting faces of the corneal pocket keeping pace temporally with repetitions of a scan pattern cycle. ### Claim 5 (depends on 4) The system of claim 4, wherein the computing unit is arranged and configured to check a coincidence of the computed refractive power of the cornea with a predetermined desired value as a third target criterion. ### Claim 6 (depends on 1) The system of claim 1, wherein grid points of a two-dimensional grid in a plane at right angles to an optical axis are predetermined as a scan pattern of the OCT device. ### Claim 7 (depends on 6) The system of claim 6, wherein the computing unit is arranged and configured to compute from the measurement data of the OCT device a three-dimensional model of a shape of the cornea and of the corneal pocket filled with the filling material. ### Claim 8 (depends on 7) The system of claim 7, wherein the computing unit is arranged and configured to keep pace temporally with a model computation, to determine astigmatism of an optical system formed by the cornea and the filled corneal pocket and to represent the optical system as a tuple of parameters. ### Claim 9 (depends on 8) The system of claim 8, wherein the computing unit is arranged and configured to check convergence of an actual-value tuple toward a predetermined desired-value tuple in terms of a minimum distance as a third target criterion. ### Claim 10 (depends on 9) The system of claim 9, wherein the computing unit is arranged and configured to compute from the actual-value tuple during fulfillment of the third target criterion and from the predetermined desired-value tuple at which edge positions the corneal pocket is to be opened up further to reduce a remaining distance between the actual-value tuple and the predetermined desired-value tuple. ### Claim 11 (depends on 10) The system of claim 10, wherein the computing unit is arranged and configured to output at which edge positions the corneal pocket is to be opened up further to reduce the remaining distance between the actual-value tuple and the desired-value tuple. ### Claim 12 (depends on 1) The system of claim 1, wherein the system is arranged and configured to correct hyperopia or presbyopia. ### Claim 13 (depends on 1) The system of claim 1, wherein the OCT device is controlled to provide a repeatedly cycled-through scan pattern, and wherein the computing unit is further configured to keep pace temporally with repetitions of the repeatedly cycled-through scan pattern during an injection.