Filler injection for treatment of small incision lenticule extraction (SMILE) overcorrection

Abstract

Systems and methods for treating refractive error resulting from small-incision lenticule extraction (SMILE) procedure. One system may include an injection system (700) including; a needle (705) and an enclosure (710). The needle (705) may be configured to inserted, via an incision (520) in a corneal peripheral of a cornea, into a pocket (550) in a stroma layer of the cornea, where the incision (520) and the pocket (550) were pre-formed during a SMILE procedure. The enclosure (710) may contain a pre-defined volume of a filler material (715). The injection system (700) may be configured to, when at least a portion of the needle (705) is inserted, via the incision (520), into the pocket (550), inject, via the needle (705), the predefined volume of the filler material (715) from the enclosure (710) into the pocket (550) in order to remediate a refractive error resulting from the SMILE procedure.

Description

FILLER INJECTION FOR TREATMENT OF SMALL INCISION LENTICULE EXTRACTION (SMILE) OVERCORRECTIONREFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 588,253, filed on October 5, 2023. The entire contents of which is incorporated herein by reference.BACKGROUND

[0002] Small incision lenticule extraction (SMILE) is a laser ablative procedure of the cornea commonly applied for myopia (nearsightedness) correction. In SMILE, intracorneal tissue, called lenticule, and a 2-3 mm incision in the comeal periphery are cut with a femtosecond laser. Unlike assisted in-situ keratomileusis (LASIK) no flap is created. The intracorneal lenticule is then manually separated from the surrounding stromal tissue with a blunt spatula and removed via the incision. By removing the intracorneal lenticule, the anterior curvature is flattened, and refractive power is decreased. Since its approval in 2015, the SMILE procedure has become increasingly popular and proven as effective and safe as LASIK. Potential advantages over LASIK are higher postoperative biomechanical stability, reduced dry eye symptoms, and no flap-related complications

[0003] Residual refractive error is a main reason for patient dissatisfaction after refractive surgery. Retreatment for correction of residual refractive error is necessary after the myopic SMILE procedure in 2.3-4.4% of all cases. Although the retreatment rate is considerably low, with over five million SMILE treatments since its approval, residual refractive error can still affect a considerable number. Reasons for retreatment include under- and over-correction. Retreatment after significant overcorrection of an initially myopic eye is more challenging as retreatment is practically a hyperopia correction.

[0004] At present, retreatment is more complex after SMILE than LASIK; several procedures are applicable depending on the anterior cap thickness, the residual comeal thickness, and the amount of retreatment. Approved retreatment methods are either surface ablative procedures, LASIK above the original SMILE interface, or secondary SMILE.Additionally, cap-to-flap conversion was recently introduced, changing the SMILE interface to a LASIK flap. Current retreatment options involve additional tissue removal, which is limited because a certain residual comeal thickness is needed to maintain biomechanical stabili ty. Previous studies attempted to circumvent extra tissue extraction by transplanting autologous tissue. However, the refractive result predictability was reduced. Moreover, certain lenticule thickness for dissection and implantation is required; thus, the correction of a low refractive error (less than 0.5 diopters (D)) can be difficult. The need for autologous tissue adds to the economic and logistic burden in clinics.SUMMARY OF THE DISCLOSURE

[0005] Refractive errors are of high prevalence in the western w orld. More than 25% of adults suffer from hyperopia, myopia, or astigmatism. However, good eyesight is a central factor for life quality. Patients sometimes consider conventional treatment methods uncomfortable, and there is a growing desire to live without external visual aid. Refractive surgeries are highly invasive, have limitations and offer no further or only cumbersome postoperative adjustment. A novel, minimally invasive procedure may include a viscous implant that is injected into the stroma, steepening the comeal curvature and thus increasing the refractive power of the cornea.

[0006] The technology disclosed herein provides improved systems and methods for treating small incision lenticule extraction SMILE overcorrection, and, more particularly, to systems and methods of injecting filler for treatment of small incision lenticule extraction SMILE overcorrection. The injection of material into the SMILE interface is distinguished from prior technologies. As one example, the technology' disclosed herein may involve injection of filler into a preformed interface having a different size than the incision (e.g., a large incision of 2-3 mm). As another example, the technology disclosed herein may be implemented with different dosimetry' (e.g., volume-dependent change in refraction) due to previous tissue removal. As another example, the technology disclosed herein may implement a filler material having a higher filler viscosity to prevent immediate leakage through the incision (e.g., a large incision of 2-3 mm). As another example, the technology disclosed herein may implement a filler material having a refractive index lower than a surrounding comeal stroma, such as, e.g., when treating low residual refractive errors, which may involve low' fillervolumes.

[0007] Accordingly, configurations described herein provide a system for treating refractive error resulting from small-incision lenticule extraction (SMILE) procedure. The system may include an injection system. The injection system may include a needle configured to be inserted, via an incision in a comeal peripheral of a cornea, into a pocket in a stroma layer of the cornea, where the incision and the pocket were pre-formed during a SMILE procedure. The injection system may include an enclosure containing a pre-defined volume of a filler material. The injection system may be configured to, when at least a portion of the needle is inserted, via the incision, into the pocket, inject, via the needle, the pre-defined volume of the filler material from the enclosure into the pocket in order to remediate a refractive error resulting from the SMILE procedure.

[0008] In some configurations, a diameter of the filler material deposited in the pocket may be less than a diameter of the incision.

[0009] In some configurations, the pre-defined volume of the filler material may be between 0.4 to 1.5 pl.

[0010] In some configurations, the filler material may have a refractive index that is less than a refractive index of a comeal stroma surrounding the pocket in order to prevent uneven material distribution.

[0011] In some configurations, the system may further include a sealing system configured to seal the incision after the pre-defined volume of the filler material is injected into the pocket.

[0012] In some configurations, the pocket may have a diameter greater than 7.0mm and the incision may have a diameter between 2-3 mm.

[0013] Some configurations described herein provide a method for treating refractive error resulting from a small-incision lenticule extraction (SMILE) procedure. The method may include providing an injection system configured to inject a filler material into a pocket in a stroma layer of a cornea, where the pocket was pre-formed during a SMILE procedure, the injection system including: a needle; and an enclosure containing a pre-defined volume of thefiller material. The method may include identifying an incision made in a comeal peripheral of the cornea, where the incision was pre-formed during the SMILE procedure. The method may include opening the incision to expose the pocket. The method may include inserting, via the incision, at least a portion of the needle of the injection system into the pocket. The method may include injecting, from the enclosure, the pre-defined volume of the filler material into the pocket. The method may include sealing the incision after injecting the pre-defined volume of the filler material into the pocket.

[0014] In some configurations, injecting the pre-defined volume of the filler material into the pocket may include injecting the pre-defined volume of the filler material into the pocket while moving the needle from an opposite side of the pocket towards the incision to prevent uneven distribution of the filler material within the pocket.

[0015] In some configurations, injecting the pre-defined volume of the filler material into the pocket may mitigate a hyperopic refractive error resulting from the previous SMILE procedure.

[0016] In some configurations, the method may further include, after sealing the incision: performing an assessment on the cornea using at least one of: optical coherence tomography; or a refractometer; and confirming, based on the assessment, at least one of: a distribution of the filler material within the pocket; or a refractive outcome resulting from the filler material being injected into the pocket.

[0017] In some configurations, injecting the pre-defined volume of the filler material into the pocket may include modifying a comeal refractive power of the cornea.

[0018] In some configurations, modifying the comeal refractive power of the cornea may include increasing the comeal refractive power by 0.6 to 6.6 dpt.

[0019] In some configurations, providing the injection system may include providing a disposable application kit, where the disposable application kit may include a micro-liter injector containing the pre-defined volume of the filler material.

[0020] In some configurations, sealing the incision after injecting the pre-defined volume of the filler material into the pocket may include sealing the incision using a least one of: tissue glue; or photo-tissue bonding.

[0021] In some configurations, injecting the pre-defined volume of the filler material into the pocket may include injecting the pre-defined volume of the filler material into the pocket such that a diameter of the filler material deposited in the pocket is less than a diameter of the incision.

[0022] The foregoing and other aspects and advantages of the present disclosure will appear from the following description. In the description, reference is made to the accompanying drawings that form a part hereof, and in which there is shown by way of illustration a preferred embodiment. This embodiment does not necessarily represent the full scope of the invention, however, and reference is therefore made to the claims and herein for interpreting the scope of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 illustrates an annotated human eyeball in the sagittal plane.

[0024] FIG. 2 illustrates a schematic representation of the anatomy of the cornea.

[0025] FIG. 3 illustrates a schematic representation of hyperopia, emmetropia, and myopia based on a model of geometric optics.

[0026] FIG. 4 illustrates an example filler injection process using representative OCT images in accordance with some configurations.

[0027] FIG. 5 A illustrates a cross sectional view of the intracorneal lenticule cut.

[0028] FIG. 5B illustrates a top view of the intracorneal lenticule cut.

[0029] FIG. 5C illustrates a cross sectional view of the removal of lenticule during aSMILE procedure.

[0030] FIG. 5D illustrates a top view of the removal of lenticule during a SMILEprocedure.

[0031] FIG. 6 is a flowchart of an example method of treating refractive error resulting from a SMILE procedure in accordance with some configurations.

[0032] FIG. 7 illustrates an example injection system in accordance with some configurations.

[0033] FIG. 8 illustrates an example treatment scheme and representative OCT images in accordance with some configurations.DETAILED DESCRIPTION

[0034] One or more embodiments are described and illustrated in the following description and accompanying drawings. These embodiments are not limited to the specific details provided herein and may be modified in various ways. Furthermore, other embodiments may exist that are not described herein. Also, the functionality' described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is "‘configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed. Furthermore, some embodiments described herein may include one or more electronic processors configured to perform the described functionality7by executing instructions stored in non-transitory, computer-readable medium. Similarly, embodiments described herein may be implemented as non-transitory. computer- readable medium storing instructions executable by one or more electronic processors to perform the described functionality. As used in the present application, “non-transitory, computer readable medium” comprises all computer-readable media but does not consist of a transitory, propagating signal. Accordingly, non-transitory computer-readable medium may include, for example, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (Read Only Memory7), a RAM (Random Access Memory), register memory, a processor cache, or any combination thereof.

[0035] In addition, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. For example, the use of “including,” “containing,” “comprising,” “having,” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “connected” and “coupled” are used broadly and encompass both direct and indirect connecting and coupling. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings and can include electrical connections or couplings, whether direct or indirect. In addition, electronic communications and notifications may be performed using wired connections, wireless connections, or a combination thereof and may be transmitted directly or through one or more intermediary devices over various types of networks, communication channels, and connections. Moreover, relational terms such as first and second, top and bottom, and the like may be used herein solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0036] Due to demographic change, refractive errors are increasing in prevalence in the western world. Generally, more than 25% of adults are affected. In addition, perfect or adequately functioning eyesight is a central factor for the quality of life and can cause severe limitations, especially for seniors, due to difficulties with reading or working on the computer. Various methods have already been established for correcting refractive errors. The most common therapy method is to make external visual aids, such as, e.g., glasses or contact lenses. A refractive error is corrected by individually adapting the geometry' and focal length of the lenses to the patient, enabling a sharp image of an observed object on the fundus of the eye. However, a growing interest in a treatment that makes wearing visual aids obsolete because, e.g., glasses are sometimes considered uncomfortable. In addition, there obviously is a need to wear them, which is why those affected have to cope with limited vision, e.g., in the event of damage or other unavailability. Refractive surgery offers possibilities here. In various procedures, the curvature of the cornea and thus the refractive power of the cornea can be manipulated by laser ablation. However, these procedures have limitations and adjustments to the corrected refraction are complicated. Although it is possible to perform additional surgery to ablate even more tissue, there is no widely accepted method to achieve an opposing effect.

[0037] These circumstances gave rise to the idea of the corneal filler, a viscous cornealimplant that is injected into the stroma. As a result, the volume can be increased, the curvature steepened, and thus the refractive power at the cornea increased. This also serves as a potential treatment for overcorrection after refractive surgery. Whenever too much corneal tissue is removed, the residual ametropia may be treated by a non-invasive therapy, or another surgery is performed to remove even more tissue to adjust the comeal curvature further. The fdler then substitutes the missing tissue.

[0038] FIG. 1 illustrates an annotated human eyeball in the sagittal plane. The outermost layer is the sclera, into which the transparent cornea is embedded at the front. Further inward are the choroid and retina. Light scattered from an object first passes through the transparent cornea, lens, and vitreous body that fills the eyeball before the light hits the back of the eye and can be perceived. FIG. 2 illustrates a schematic representation of the anatomy of the cornea.

[0039] Myopia and hyperopia mainly result from an abnormal length of the eyeball, which may lead to the retina not being in the lens’s focus. Therefore, rays emanating from one object point do not come together in one point at the retina again. A blurred image is created. The refractive power of the actual lens is less likely to be the cause. When the eyeball is too short, this is referred to as hyperopia (farsightedness). When the eyeball is too long, it is referred to as myopia (nearsightedness), as illustrated in FIG. 3. FIG. 3 illustrates a schematic representation of hyperopia (represented in FIG. 3 by “H”), emmetropia (represented in FIG. 3 by “E”), and myopia (represented in FIG. 3 by “M”) based on a model of geometric optics. In emmetropia, the focal point of the lens is on the retina. In ametropia, the focal point of the les is not on the retina. Affected individuals are, at least to some degree of severity, able to accommodate a sharp image despite ametropia, although this may involve subjective effort.

[0040] The symptoms of presbyopia, also known as age-related farsightedness, already appear after age 40. The reason for symptoms is an age-related loss of elasticity and thus the lens’s ability to accommodate. As a result, those affected can often see nearby objects, such as writing, less clearly. Unlike similar visual disorders, presbyopia, or in general the loss of elasticity of the lens, may be viewed as a physiological change rather than a condition that affects everyone. This underlines the potential of the filler treatment.

[0041] Different forms of ametropia are related to different therapies. As mentionedbefore, glasses are the most common measure to cope with ametropia. The lenses’ focal length is adapted to the refractive error to compensate for ametropia. Myopia and hyperopia are corrected with convex or concave lenses. Astigmatism can be corrected with a cylindrical lens, which refracts light orthogonally to its axis. These lenses can also be used as contact lenses. However, those affected have an increasing desire for therapy that works independently from an external visual aid. Glasses or contact lenses can be uncomfortable or not easy to use in some everyday situations. In addition, there obviously is a need to wear them, which is why those affected have to cope with limited vision, e.g., in the event of damage or other unavailability. From this demand, refractive surgery developed. Here, ametropia is corrected by laser-based invasive interventions, where comeal tissue is removed. The curvature is flattened in myopia and the curvature is steepened in hyperopia.

[0042] One procedure is laser in-situ keratomileusis (LASIK). The comeal epithelium is loosened and opened (forming a “flap”) in this surgery using a laser. This allows tissue to be laser-ablated in the stroma and thus changes the radius of the anterior eye. The flap is then placed back on the eye. With LASIK, myopia can be treated much better than hyperopia or presbyopia. Here, corrections of up to +3 dpt are possible. Depending on the patient, even less may be possible, or in complicated cases, e.g., when the tissue is too thin, no treatment can be carried out at all.

[0043] Furthermore, as noted herein, there is SMILE for myopia correction. In contrast to LASIK, SMILE does not generate a flap, but a lenticule in the stroma is cut loose with a laser without damaging the epithelium. This lenticule is then pulled out by an ophthalmologist through a 2-3 mm wide incision. SMILE-related corrections offer a target for the comeal filler. First, in some cases, overcorrection happens. The liquid implant could suffice as a substitution for stromal tissue. Second, as mentioned before, presbyopia is a disease of high prevalence. Patients treated with SMILE at ayounger age often experience a subjective change of the eye’s focal point and become farsighted. A further adjustment with a filler could suffice as a counteract.

[0044] Other procedures in refractive surgery are, e.g., refractive lens exchange. The natural lens (oculus lens) is replaced by a prosthesis. Presbyopia can often be treated well in this way. However, refractive lens exchange that can be associated with many risks andcomplications and is generally avoided when other procedures can be used. Further, the severity of the ametropia may not justify refractive surgery.

[0045] The potential of a comeal fdler injection results from the limitations of the therapy methods discussed herein. Here, presbyopia is to be corrected by giving the anterior surface of the cornea a steeper curvature and thus greater refractive power through a viscous implant. For this purpose, a “pocket” is created using, e.g., a femtosecond laser, into which hyaluronic acid is injected through a thin cannula. When a SMILE is performed, the tissue interface is used as a filler cavity . The expansion also flattens the posterior surface, which further increases refractive power.

[0046] FIG. 4 illustrates an example filler injection process 400 using representative OCT images in accordance with some configurations. The representative OCT images of FIG. 4 each include an anterior curvature 405, a peripheral posterior curvature 410, and a central posterior curvature 415. FIG. 4 includes a representative B-scan (represented in FIG. 4 by reference numeral 420) before filler treatment (represented in FIG. 4 by reference numeral 425). As illustrated in FIG. 4, the filler injection (represented in FIG. 4 by reference numeral 425) may result in flattening of the posterior comeal surface (represented in FIG. 4 by reference numeral 430). The example of FIG. 4 illustrates a small, deep pocket that would counteract presbyopia by inducing an increase in central refraction power.

[0047] A pocket 450 near the posterior surface can be seen in the example of FIG. 4. Correction properties can be varied by changing the depth and extent of the filler pocket (e.g., the pocket 450 of FIG. 4). In terms of a curvature’s refractive power (referred to herein as P), the following applies:where n2~ 1.376 represents the refractive index of the cornea, n, ~ I represents the refractive index of air (or any previous medium), and r represents the radius of the cornea surface. In order to be able to estimate the changes in refractive power precisely, the radii of the cornea may be measured using, e.g., image processing methods.

[0048] As noted herein, a SMILE is a refractive surgery treatment for myopia. As partof a SMILE, a laser cuts a round piece of tissue within the stroma while the eye is fixated without damaging the epithelium. After that, an incision of 2 mm is cut outside the eye's optical zone forming an exit for the lenticule. Eventually, the patient is detached from the laser and a surgeon removes the lenticule manually. The incision may be sealed by the healing of the epithelium. This process flattens the cornea's anterior curvature, resulting in a decrease in refractive power, as described herein with respect to FIG. 4.

[0049] Although SMILE in general is a reliable method, in some cases the refractive power after the procedure is lower than aimed. This is referred to as overcorrection. The residual ametropia then has to be treated with further surgery or an external visual aid (e.g., glasses, contact lenses, etc.). In such cases, the filler implant shows high potential in counteracting the slight overcorrection.

[0050] Another potential field of application poses a filler treatment of patients that received SMILE at a younger age. Due to presbyopia, the focus at relaxation moves further from the eye and it is necessary to compensate this through accommodation. Hence, steepening the comeal curvature again may help to cope with the symptoms of presbyopia. Furthermore, since there already was a SMILE performed, there is already a cavity for filler injection making the procedure very convenient.

[0051] Accordingly, the technology disclosed herein provides systems and methods to treat refractive error resulting from a SMILE procedure. For instance, in some configurations, the technology disclosed herein provides a method for treating overcorrection after myopic SMILE. For example, FIGS. 5A-5D illustrate cross sectional and top views of an example of an intracorneal lenticule cut 505 and removal of lenticule 510 from an eye during a SMILE procedure. In particular, FIG. 5A is a cross sectional view of the intracorneal lenticule cut 505. FIG. 5B is a top view of the intracorneal lenticule cut 505. FIG. 5C is a cross sectional view of the removal of the lenticule 510 during a SMILE procedure. FIG. 5D is a top view7of the removal of the lenticule 510 during a SMILE procedure. FIGS. 5A-5D also illustrate an example anterior cap 515 and an incision 520 in which the lenticule 510 is removed. In the eyes illustrated in FIGS. 5A-5B, too much tissue (e g., lenticule 510) was removed during the SMILE procedure resulting in a hyperopic refractive error (e.g., an overcorrection). After the initial myopic SMILE procedure, the refractive outcome may be assessed after one weekpostoperatively.

[0052] In some instances, the lenticule 510 being removed may have a diameter of approximately 6.0-6.5 mm and the incision 520 through which the lenticule 510 is removed may have a diameter of approximately 2-3 mm. As noted above, with respect to the example of FIGS. 5A-5D, the SMILE procedure resulted in an overcorrection (e.g., a hyperopic refractive error) caused by removing too much of the lenticule 510. For instance, after removal of the lenticule 510, a pocket 550 (e.g., the pocket 450 of FIG. 4) may be formed, as described herein with respect to FIG. 4. In some instances, the pocket 550 may have a diameter greater than approximately 7.0mm, such as, e.g., a diameter between 7.2-7.7mm.

[0053] After the initial myopic SMILE procedure, the refractive outcome may be assessed, e.g., after one week postoperatively. In the case of overcorrection (e.g., too much tissue was removed), the technology disclosed herein provides methods and systems to treat refractive error resulting from a SMILE procedure (e.g.. SMILE overcorrection). For example, the technology disclosed herein may provide a method that may include injection of a material (such as, e.g., a transparent filler material as described in greater detail herein) into a pocket (e.g., the pocket 450, 550) (also referred to herein as the SMILE interface), which was preformed with the removal of the lenticule 510 during the initial SMILE procedure, and subsequent sealing of the incision 520 in the comeal periphery.

[0054] For example, FIG. 6 is a flowchart of an example method of treating refractive error resulting from a SMILE procedure in accordance with some configurations. As illustrated in FIG. 6, the method 600 may include providing an injection system configured to inject a filler material into a pocket (e.g., the pocket 550) in a stroma layer of a cornea (at block 605). As noted herein, in some configurations, the pocket 550 was pre-formed during a previous SMILE procedure.

[0055] FIG. 7 illustrates an example injection system 700 in accordance with some configurations. As illustrated in FIG. 7, the injection system 700 may include a needle 705 coupled to an enclosure 710. The enclosure 710 may contain (or otherwise include) a material 715. In some configurations, the needle 705 is coupled (or otherwise attached) to the enclosure 710 such that the material 715 contained within the enclosure 710 may be transferred from the enclosure 710 to the needle 705, and, in some instances, be expelled (or otherwise injected)from the needle 705. In some instances, the injection system 700 may be included in (or as part of) a disposable application kit (e.g., a single use application kit). As one example, the disposable application kit may include a micro-liter injector containing the pre-defined volume of the material 715 (e.g., the injection system 700).

[0056] The needle 705 may be, e.g., a hollow needle, a blunt needle, etc. of varied size. As one example, the needle 705 may be a 30 gauge-blunt-ended needle. The enclosure 710 may be a syringe, such as, e.g., a microliter syringe. In some configurations, the injection system 700 may be a 30-gaguge-blunt-ended needle attached to a microliter syringe.

[0057] The material 715 may be a filler material. For example, the material 715 may be a transparent filler material. In some examples, the material 715 may be specific to the treatment of SMILE overcorrection (e.g., treating refractive error resulting from a SMILE procedure). In some configurations, the material 715 may have a predetermined viscosity'. For instance, due to the diameter of the incision 520 (e.g.. 2-3mm in diameter) the viscosity of the material 715 may be predetermined in order to prevent immediate leakage. In some examples, the viscosity7of the material 715 may be higher than traditional filler materials implemented within the optical industry.

[0058] Alternatively, or in addition, in some configurations, the degree of overcorrection from myopic SMILE may be low (e.g., less than 2-3mm, such as, e.g., 1mm). Accordingly, in some configurations, a small amount of the material 715 may be used to treat the refractive error (e.g., between approximately 0.4 to 1.5pl). For instance, in some configurations, the material 715 may have a pre-defined volume, where the pre-defined volume corresponds to a degree of overcorrection (e.g., a volume associated with correcting the degree of overcorrection). As such, in some instances, small volumes of the material 715 may be implemented to correct (or otherwise remediate) the hyperopic refractive error. In such instances, the small volume may result in uneven distribution of the material 715 within the pocket 550. For instance, the pocket 550 may have a "‘large” diameter (e.g., over 77mm, such as, e.g., 7.2-7.6mm) relative to the volume of the material 715 to be used to remediate the hyperopic refractive error (e.g., a volume having a diameter, when deposited within the pocket 550, less than 2-3mm. such as, e.g.. 1mm; or a volume between approximately 0.4 to 1.5pl). Accordingly, in some configurations, the pre-defined volume of the material 715 maycorrespond to a diameter of the material 714 deposited in the pocket 550 (e.g., the pre-defmed volume may translate to a particular diameter when deposited in the pocket 550). As such, in some configurations, the diameter of the material 715 deposited in the pocket 550 is less than a diameter of the incision 520. As one example, the diameter of the material 715 deposited in the pocket 550 may be approximately 1mm and the diameter of the incision 520 may be between approximately 2-3mm. In some configurations, the pre-defmed volume may be between approximately 0.4 to 1.5 pl.

[0059] In some instances, to prevent uneven distribution of the material 715 within the pocket 550, the material 715 may have a refractive index that is lower than a refractive index of the surrounding comeal stroma, decreasing the volume-dependent refractive change. As a result, a larger volume of the material 715 may be utilized to achieve a change in refraction that corrects (or otherwise remediates) the hyperopic refractive error resulting from the SMILE overcorrection.

[0060] As illustrated in FIG. 6, the method 600 may include identifying the incision 520 made in a comeal peripheral of the cornea (at block 610). As noted herein, in some configurations, the incision 520 was pre-formed during a SMILE procedure (e.g., the initial or previous SMILE procedure). After identifying the incision 520, the method 600 may include opening the incision 520 to expose the pocket 550 (at block 615). In some configurations, the incision 520 may be opened partially or fully.

[0061] The incision 520 may be opened using, e.g.. a blunt spatula. In some configurations, the incision 520 may be re-opened (or otherwise cut open) to provide access to the pocket 550. Once the incision 520 is re-opened, the method 600 may include inserting, via the incision 520, at least a portion of the needle 705 of the injection system 700 into the pocket 550 (at block 620).

[0062] The method 600 may include injecting, from the enclosure 710, the pre-defined volume of the material 715 into the pocket 550 (at block 625). In some configurations, injecting the pre-defined volume of the material 715 into the pocket 550 may modify a comeal refractive power of the cornea, which may. ultimately, correct (or otherwise remediate) a refractive error resulting from the SMILE procedure (e.g., the initial or previous SMILE procedure). In some instances, injecting the pre-defmed volume of the material 715 into the pocket 550 may resultin an increase in the corneal refractive power. As one example, after injecting the pre-defined volume of the material 715 into the pocket 550. the comeal refractive power may increase by approximately 0.6 to 6.6 dpt.

[0063] In some configurations, while the pre-defined volume of the material 715 is being injected into the pocket 550. the injection system 700 (e.g., the needle 705) may be moved (or otherwise repositioned) from an opposite side of the pocket 550 towards the incision 520. For instance, while injecting the material 715 into the pocket 550, the needle 705 may be gradually or continuously repositioned such that the needle 705 moves away from an opposite side of the pocket towards the incision 520. Repositioning of the injection system 700 (e.g., the needle 705) during injection of the material 715 into the pocket 550 may allow for an even distribution of the material 715 within the pocket 550 (e.g., remediate or prevent an uneven distribution of the material 715 within the pocket 550).

[0064] The method 600 may include sealing (or re-sealing) the incision 520 after injecting the pre-defined volume of the material 715 into the pocket 550 (at block 630). For instance, in some configurations, after injection of the pre-defined volume of the material 715, the incision 520 may be sealed (e.g., immediately sealed after or while the needle 705 is removed). For example, the incision 520 may be sealed using tissue glue, photo-tissue bonding, etc. In some configurations, the incision 520 may be sealed using a sealing system or kit. The sealing system or kit may be configured to seal the incision 520, such as, e.g., with tissue glue or photo-tissue bonding (cross-linking). In some instances, the sealing system or kit may be included as part of the disposable application kit described herein. As such, in some instances, the disposable application kit may include the injection system 700 and the sealing system or kit.

[0065] A distribution of the material 715 within the pocket 550 or a refractive outcome may be assessed by optical coherence tomography (OCT) or refractometer, respectively. Accordingly, in some configurations, the method 600 may include performing an assessment on the cornea after sealing the incision 520. Such an assessment may include using OCT to determine a distribution of the material 715 deposited within the pocket 550. Alternatively, or in addition, the assessment may include using a refractometer to determine a refractive outcome resulting from the material 715 being injected into the pocket 550. Based on the assessment,the incision 520 may be reopened to adjust a volume of the material 715 deposited within the pocket 550 for. e.g., the anticipated refractive change.

[0066] The feasibility of the systems and methods disclosed herein has been extensively tested in ex-vivo experiments using fresh (<24 h postmortem) ex-vivo pig eyes. The experimental settings were as follows: The ex-vivo pig eyes were mounted on a customized eye holder, and a water column was attached to maintain physiologic intraocular pressure. Before performance of a SMILE procedure, a commercial OCT device (using a wavelength of 930 nm) was used to acquire a cornea baseline profile of the ex-vivo pig eyes. A customized algorithm was implemented to correct OCT system-immanent field distortion and apply a surface fit of the anterior and posterior comeal curvature. The eye globes underwent a conventional myopic SMILE procedure using a 500-kHz femtosecond surgical laser with a pulse energy7of 150nJ and track / spot distance of 2 pm. The lenticule size was set to 6mm in diameter with a minimum lenticule thickness of 15pm. The cap thickness and diameter of the lenticule were 120pm and 7.2mm. respectively. After the SMILE procedure, another 3D-OCT scan of the cornea was performed to document comeal profile changes. After manual lenticule removal (as performed in standard SMILE procedures), the material 715 was injected using a 30-gauge-blunt-ended needle attached to a microliter syringe via the SMILE incision (e.g., the incision 520). The incision 520 was sealed with tissue fibrin glue. 3D-OCT images were acquired directly after injection of the material 715.

[0067] FIG. 8 illustrates a treatment scheme 805 and representative OCT images 810. As illustrated in FIG. 8, the treatment scheme 805 includes a SMILE procedure stage 815, a filler injection stage 820, and an intracorneal filler stage 825. The SMILE procedure stage 815 represents performance of a SMILE procedure (e.g., the initial SMILE procedure), in which tissue is removed. The filler injection stage 820 represents injection of the material 715 through the incision 520 into the pocket 550 preformed during the SMILE procedure stage 815. The intracorneal filler stage 825 represents a result of injecting the material 715 into the pocket 550. As noted, FIG. 8 associates respective OCT images 810 with each stage of the treatment scheme 805. For instance, the SMILE procedure stage 815 is associated with a first OCT image 810A. The first OCT image 810A represents a baseline (e.g., a cornea baseline profile) prior to performance of the SMILE procedure. The filler injection stage 820 is associated with a second OCT image 810B. The second OCT image 810B is an OCT image captured after performanceof the SMILE procedure. The intracorneal filler stage 825 is associated with a third OCT image 810C. The third OCT image 810C is an OCT image captured after injection of the material 715 into the pocket 550.

[0068] A total cornea refractive power decrease of -4.6 ± 0.9 dpt (D) was measured following myopic SMILE treatment in the ex-vivo pig eyes. A filler volume ranging from 0.4 to 1.5pl was injected into the pocket 550. increasing comeal refractive power by 0.6 to 6.6 dpt (D). High inter-individual variability was observ ed in the volume-dependent change in comeal refractive power, which was related to the surgical manipulation of the ex-vivo pig eyes. It was thus demonstrated that comeal filler injection into the SMILE interface (e.g., the pocket 550 via the incision 520) is, in principle, feasible for correcting myopic SMILE overcorrection (e.g., treating refractive error resulting from a SMILE procedure).

[0069] Accordingly, the technology disclosed herein provides methods and systems for the injection of material into the SMILE interface that is distinguished from prior technologies based at least on the following: (1) injection is into a pre-formed interface of different sizing (e.g., a relatively large incision, such as, e.g., 2-3mm), (2) because different dosimetry (volume-dependent change in refraction) is implemented due to the previous tissue removal, (3) the large incision of 2-3mm may include a higher filler viscosity to prevent immediate leakage through the incision and (4) because low filler volumes may be used (e.g., for treating low residual refractive errors), a filler material with a refractive index lower than the surrounding comeal stroma.

[0070] In some configurations, the technology disclosed herein may provide a readymade micro-liter injector containing a pre-defined filler material volume as a disposable application kit. Alternatively, or in addition, the technology disclosed herein may provide a filler material specific to the treatment of SMILE overcorrection. Alternatively, or in addition, the technology disclosed herein may provide a ready-made sealing kit for preventing filler leakage.

[0071] The present disclosure has described one or more preferred embodiments, and it should be appreciated that many equivalents, alternatives, variations, and modifications, aside from those expressly stated, are possible and within the scope of the embodiments described herein.

Claims

CLAIMSWhat is claimed is:

1. A system for treating refractive error resulting from small-incision lenticule extraction (SMILE) procedure, the system comprising: an injection system (700) including: a needle (705) configured to be inserted, via an incision (520) in a comeal peripheral of a cornea, into a pocket (550) in a stroma layer of the cornea, wherein the incision (520) and the pocket (550) were pre-formed during a SMILE procedure; and an enclosure (710) containing a pre-defined volume of a filler material (715); and wherein the injection system (700) is configured to: when at least a portion of the needle (705) is inserted, via the incision (520), into the pocket (550), inject, via the needle (705), the pre-defined volume of the filler material (715) from the enclosure (710) into the pocket (550) in order to remediate a refractive error resulting from the SMILE procedure.

2. The system of claim 1, wherein a diameter of the filler material (715) deposited in the pocket (550) is less than a diameter of the incision (520).

3. The system of claim 1, wherein the pre-defined volume of the filler material (715) is between 0.4 to 1.5pl.

4. The system of claim 1, wherein the filler material (715) has a refractive index that is less than a refractive index of a comeal stroma surrounding the pocket (550) in order to prevent uneven material distribution.

5. The system of claim 1, further comprising: a sealing system configured to seal the incision (520) after the pre-defined volume of the filler material (715) is injected into the pocket (550).

6. The system of claim 1, wherein the pocket (550) has a diameter greater than 7.0mm and the incision (520) has a diameter between 2-3 mm.

7. A method (600) of treating refractive error resulting from a small-incision lenticule extraction (SMILE) procedure, the method comprising: providing an injection system (700) configured to inject a filler material (715) into a pocket (550) in a stroma layer of a cornea, wherein the pocket (550) was pre-formed during a SMILE procedure, the injection system (700) including: a needle (705); and an enclosure (710) containing a pre-defined volume of the filler material (715); identifying an incision (520) made in a comeal peripheral of the cornea, wherein the incision (520) was pre-formed during the SMILE procedure; opening the incision (520) to expose the pocket (550); inserting, via the incision (520), at least a portion of the needle (705) of the injection system (700) into the pocket (550); injecting, from the enclosure (710), the pre-defined volume of the filler material (715) into the pocket (550); and sealing the incision (520) after injecting the pre-defined volume of the filler material (715) into the pocket (550).

8. The method (600) of claim 7, wherein injecting the pre-defmed volume of the filler material (715) into the pocket (550) includes injecting the pre-defmed volume of the filler material (715) into the pocket (550) while moving the needle (705) from an opposite side of the pocket (550) towards the incision (520) to prevent uneven distribution of the filler material (715) within the pocket (550).

9. The method (600) of claim 7, wherein injecting the pre-defmed volume of the filler material (715) into the pocket (550) mitigates a hyperopic refractive error resulting from the previous SMILE procedure.

10. The method (700) of claim 7, further comprising: after sealing the incision (520), performing an assessment on the cornea using at least one of: optical coherence tomography; or a refractometer; and confirming, based on the assessment, at least one of: a distribution of the filler material (715) within the pocket (550); or a refractive outcome resulting from the filler material (715) being injected into the pocket (550).

11. The method (600) of claim 7, wherein injecting the pre-defined volume of the filler material (715) into the pocket (550) includes modifying a comeal refractive power of the cornea.

12. The method (600) of claim 11. wherein modifying the comeal refractive power of the cornea includes increasing the corneal refractive power by 0.6 to 6.6 dpt.

13. The method (600) of claim 7, wherein providing the injection system (700) includes providing a disposable application kit. wherein the disposable application kit includes a micro-liter injector containing the pre-defined volume of the filler material (715).

14. The method (600) of claim 7, wherein sealing the incision (520) after injecting the pre-defined volume of the filler material (715) into the pocket (550) includes sealing the incision (520) using a least one of: tissue glue; or photo-tissue bonding.

15. The method (600) of claim 7, wherein injecting the pre-defined volume of the filler material (715) into the pocket (550) includes injecting the pre-defined volume of the filler material (715) into the pocket (550) such that a diameter of the filler material (715) deposited in the pocket (550) is less than a diameter of the incision (520).

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