Patent Application
20080075756
Accommodation: As used herein, “accommodation” refers to the eye's ability to automatically change focus from seeing at one distance to seeing at another.
Enhance lens regeneration: As used herein, “enhance lens regeneration” and variants of the same phrase include increasing the probability of a lens regenerating after extracapsular lens extraction wherein the lens will have less haze, less striae or fewer folds than it otherwise would have had without a described treatment or is a regenerative lens that is more clear than it otherwise would have been with a described treatment.
Functional acryl groups: As used herein, “functional acryl groups” include molecules having functional groups attached thereto including an acryl group moiety, so as to become acryl-bearing, by acryl attachment to the monomers of a backbone, its terminal ends, or both. The acryl groups in these functional groups can be linked to the atoms by spacers. Examples of functional acryl groups include, without limitation, acrylamidopropyl, methacrylamidopropyl, acryloxyhexyl and methacryloxyhexyl. In certain embodiments, “functional acryl groups” include polysiloxane molecules having functional groups attached thereto including an acryl group moiety, so as to become acryl-bearing, by acryl attachment to the siloxane monomers of the polysiloxane backbone, its terminal ends, or both. The acryl groups in these functional groups can be linked to the silicone atoms by spacers. In one embodiment, the functional acryl groups are attached to the terminal ends of polysiloxane molecules, as exemplified by, without limitation, acrylamidopropyl-, methacrylamidopropyl-, acryloxyhexyl- and methacryloxyhexyl-terminated polysiloxanes. Those skilled in the art can consider numerous such alternatives which maintain the basic function of having an acryl group for subsequent crosslinking/polymerization of the polysiloxane molecules into larger network together with a photoinitiator. In the same manner it is also to be understood that the meaning of acryl group includes acryl or substituted acryl, such as, without limitation, methacryl, moieties attached through a variety of linkages including ester, amide and urethane linkages, or functional analogues of acryl capable of undergoing crosslinking reactions with a photoinitiator.
The present invention is based on the concept that the natural lens is capable of controlled or enhanced organic cellular or biological regeneration following endocapsular lens and/or cataract extraction. In various embodiments, the present invention provides methods to contribute to the production of a regenerated lens with properties similar to that of the natural lens, including, without limitation, clarity, protein content, histology, focusing power, spectral transmission and accommodative ability. In one embodiment, the natural regenerating lens tissue can be directed to grow in a more natural or regular pattern around a suitably flexible and biocompatible polymeric lens.
The concept of implanting a suitably flexible polymeric lens compatible with naturally regenerating lens tissue was previously suggested by studies in which Acuvue® contact lenses (etafilcon A, 58% H2O; available from Johnson & Johnson Vision Care, Inc., Jacksonville, Fla.) were modified for intralenticular implantation in the rabbit eye. While normal regeneration was noted in one eye, the results were inconsistent and the nucleus of most regenerated lenses contained a star-shaped opacity related to the irregular growth pattern and misalignment of the earliest lens fibers.
In numerous studies, lenses that have been regenerated following endocapsular lens extraction in New Zealand Albino rabbits have been irregular in shape, appearing primarily doughnut-shaped. The newly formed lenses are irregular in shape as a result of the lack of lens growth at the site of the anterior capsulotomy and its adhesion to the posterior capsule. These regenerated lenses have had variable translucency because of irregular alignment of newly formed fibers, which may partly result from irregular proliferation of cells in zones of wrinkling or folding of the lens capsule in the early postoperative period. To improve the transparency of the regenerated lenses and their therapeutic utility, investigators have attempted to mimic the embryonic environment with limited success.
The various embodiments of the present invention reaffirm past findings in the art showing lens regeneration and demonstrate that regeneration of the lens can be enhanced through the use of polymer containing compositions including, in certain embodiments, through the use of polysiloxane polymer containing compositions. Certain embodiments according to the present invention also incorporate the use of viscoelastic materials including, without limitation, hyaluronic acid, cellulosic materials, collagen, and combinations thereof to further enhance lens regeneration. Embodiments according to the present invention can also enhance lens regeneration by restoring lens capsule integrity following the administration of polymer or polysiloxane polymer containing compositions.
The present invention provides methods of enhancing lens regeneration using materials comprising polymers. Certain embodiments include methods of enhancing lens regeneration using materials comprising polysiloxane polymers. Surgeons or researchers can inject the material into a capsular bag to form a lens or scaffold onto and around which lens cells can regenerate and organize.
Specifically, in one embodiment according to the present invention the invention is a method comprising enhancing regeneration of lens cells in a mammal after endocapsular extraction by filling a lens capsule bag of the mammal with an injectable lens material comprising a polymer wherein the injectable lens material has a viscosity for being injected through standard cannula and the polymer has functional groups at terminal ends of the polymer. In certain embodiments the polymer used in accordance with the present invention comprises a polysiloxane polymer. In certain other embodiments, the polymer used in accordance with the present invention comprises a polysiloxanes polymer with functional acryl groups.
In another embodiment of the methods, the endocapsular extraction occurs through a capsulorrhexis that is 3 millimeters or less.
Embodiment of the presently described methods can also further comprise one or more of: (i) inserting a foldable intraocular lens into the capsule bag of the mammal; (ii) positioning a contact lens or similar polymeric material in the form of a permeable or semi-permeable disc shaped lens material between the anterior capsule and the injectable lens material or between the injectable lens material and the posterior capsule; (iii) administering viscoelastic materials including, without limitation, one or more of hyaluronic acid, cellulosic materials, collagen, and combinations thereof (in one embodiment Healon® brand hyaluronic acid) to the capsule bag of the mammal; (iv) administering hyaluronidase to the capsule bag of the mammal; and (v) inserting at least one collagen patch in the capsule bag of the mammal.
In another embodiment of the methods, the injectable lens material further comprises a photoinitiator and is capable of being photopolymerized into a solid intraocular lens.
In yet another embodiment of the methods, a polysiloxane polymer used in accordance with the present invention has a backbone of the general formula:
wherein R1 and R2 are independently C1-C6 alkyl; R3 is phenyl; R4 is phenyl or C1-C6 alkyl; R5 is CF3(CH2)x wherein x is 1-5; R6 is C1-C6 alkyl or fluoroalkyl; l is in the molar fraction range of 0 to 0.95; m is in the molar fraction range of from greater than 0 to 0.7; and n is in the molar fraction range of from greater than 0 to 0.65. As will be understood by one of ordinary skill in the art, in certain embodiments it will be beneficial to bind, x-link or otherwise join a viscoelastic material such as, without limitation, hyaluronic acid with this polysiloxane material (i.e. a fixed hyaluronic acid coating). This would facilitate the viscoelastic material staying positioned correctly.
The present invention also includes kits. Kits according to the present invention can comprises instructional materials and one or both of (i) a polysiloxane polymer; and (ii) a photocurable polysiloxane polymer and wherein the kit can also comprise one or more of (i) viscoelastic materials including, without limitation, one or more of hyaluronic acid, cellulosic materials, collagen, and combinations thereof; (ii) hyaluronidase; (iii) a collagen patch; (iv) an intraocular lens; and (v) a contact lens or similar polymeric material in the form of a permeable or semi-permeable disc shaped lens material. The instructional materials of these kits instruct the use of the included components in enhancing the regeneration of lens cells. In alternative embodiments, the instructional materials can also direct that the endocapsular extraction occurs through a capsulorrhexis that is 3 millimeters or less in diameter.
In another embodiment of the kits, the polysiloxane polymer has a backbone of the general formula:
wherein R1 and R2 are independently C1-C6 alkyl; R3 is phenyl; R4 is phenyl or C1-C6 alkyl; R5 is CF3(CH2)x wherein x is 1-5; R6 is C1-C6 alkyl or fluoroalkyl; l is in the molar fraction range of 0 to 0.95; m is in the molar fraction range of from greater than 0 to 0.7; and n is in the molar fraction range of from greater than 0 to 0.65. Again, and as will be understood by one of ordinary skill in the art, in certain embodiments it will be beneficial to bind, x-link or otherwise join a viscoelastic material such as, without limitation, hyaluronic acid with this polysiloxane material (i.e. a fixed hyaluronic acid coating).
The following in vivo studies evaluated the use of polymers, including polysiloxane polymers, following endocapsular lens extraction in young and old New Zealand white rabbits.
The polymer material used in the presently described studies included a polysiloxane polymer obtained from AMO Groningen B.V. (Groningen, Holland) that corresponded to composition AS4-11, CS0402014. Silicone plugs (4.5 mm) were also obtained from AMO Groningen B.V. (Groningen, Holland). “Shark Tooth” Phaco needles, (LAMINAR® Flow Phaco Tip15Ω/45Ω) and infusion sleeve (20 gauge, OPO154520L) were obtained from Advanced Medical Optics, Inc. (Santa Ana, Calif.). Healon 5® brand hyaluronic acid was obtained from AMO USA, Inc. (Santa Ana, Calif.).
The general health and acceptability of animals used in the following studies was established prior to surgery. A total of 7 New Zealand white rabbits were used in three studies. During surgery, rabbits were anesthetized with about 5 mg/kg xylazine and about 50 mg/kg ketamine HCl, intramuscularly. The surgical eye was dilated with 1% cyclopentolate and 10% phenylephrine; eyelashes were trimmed; and the ocular area was disinfected with povidone iodine. A wire lid speculum was inserted to retract the lids, and a corneal incision was made at 12:00 with a 2.85 mm keratome. Healon 5® brand hyaluronic acid was injected to maintain anterior chamber depth and an about 2-3 mm continuous curvilinear capsulorrhexis was performed. A 20 gauge phacoemulsification tip was inserted through the corneal wound and endocapsular lens extraction was performed by phacoemulsification and irrigation/aspiration with balanced salt solution (BSS). Considerable care was taken to remove all lens cortical material by diligent irrigation and aspiration. A 4.5 mm silicone plug was inserted into the capsule bag and maneuvered behind the anterior capsulotomy and the polysiloxane polymer material was injected into the capsule bag using a 20 gauge cannula. At the completion of the procedure, the corneal incision was closed with 10-0 nylon sutures and 0.25 ml (20 mg) of gentamicin and 0.1 ml of dexamethasone (2 mg) was injected subconjunctivally every 3 days for two weeks.
The overall positional stability of the silicone plug was evaluated based on the slit lamp observation of placement in the capsule bag. Observations of conjunctiva, corneal pathology, anterior chamber cells, flare and fibrin, posterior synechiae, capsular bag shape, and percent lens regrowth in the capsule bag were recorded.
All slit lamp findings were graded on a scale of 0 to 4 (0=none, 1+=trace, 2+=mild, 3+=moderate, 4+=severe). Throughout the experimental period, rabbits were observed for any abnormal clinical signs, including any abnormal ocular findings such as pain, excessive hyperemia or discharge. Grading of the ocular findings was based on the methods of McDonald and Shadduck (McDonald, T. O., and Shadduck, J. A. Eye Irritation. Advances in Modern Toxicology, Vol. 4, pp. 162-166. Dermatotoxicology and Pharmacology. Eds. Marzulli and Maibach. Washington: Hemisphere, 1977) which is incorporated by reference herein for all that it teaches regarding the grading of ocular findings. All observations were recorded on a Slit Lamp Examination form. Grading for each of these parameters was done as follows:
Cornea: Scores recorded for the cornea reflect the greatest severity of corneal edema/cloudiness observed. Severity of corneal cloudiness was graded as follows:
Cells in the anterior chamber: The presence/absence of cells in the anterior chamber was monitored as follows:
Anterior chamber flare: Anterior chamber flare was graded on the intensity of the Tyndall phenomenon and was scored by comparing the normal Tyndall effect observed when the slit lamp passes through the lens with that seen in the anterior chamber:
Fibrin in the anterior chamber: The presence/absence of fibrin in the anterior chamber was monitored as follows:
Posterior Synechia: The presence/absence of iris adhesion to the lens capsule is known as posterior synechia and was graded as follows:
At the end of the studies, animals were euthanized by an injection of sodium pentobarbital (Eutha-6, Western Medical Supply Co., Inc.) into the marginal ear vein. At all times animals were treated in accordance with USDA guidelines and the ARVO Resolution on the Use of Animals in Research.
The study described in Example 1 evaluated: (i) posterior capsule opacification when a foldable silicone IOL in combination with the polysiloxane polymer material is used and (ii) the surgical technique for performing endocapsular extraction through a small 2 mm capsulorrhexis in an older rabbit with a hard lens.
In this study, rabbit 71719 (New Zealand white female; weight 2.4 kg) was 3 months old and rabbits 71565 and 71566 (New Zealand white females; weight 3.5 kg) were 3 years old.
Rabbit 71719 OD, OS: Uneventful endocapsular lens extractions were performed through a 2.0 mm capsulorrhexis using a 20 gauge phaco needle with Healon 5® brand hyaluronic acid for anterior chamber maintenance. During phaco, the capsulorrhexis stretched and a 4.5 mm silicone plug was positioned under the capsulorrhexis. In 71719 OD, the polysiloxane polymer material containing a few small bubbles was injected with a 20 gauge cannula on a 3 cc syringe. In 71719 OS, a SI-40NB IOL devoid of haptics was inserted into the capsule bag with the Silver Insertion System and the polysiloxane polymer material was injected into capsule bag in front of the IOL.
Rabbits 71565 and 71566: In these 3 year old large rabbits, the lens nucleus density was estimated to be 3-4+. Endocapsular lens extractions were performed through a 2.0 mm capsulorrhexis using a 21 gauge Shark Tooth Phaco needle with Healon 5® brand hyaluronic acid for anterior chamber maintenance. The Phaco time for 71565 OD was 20 minutes. The Phaco time for 71565 OS was 18 minutes. Following lens removal, rabbit 71565 was euthanized. The Phaco time for 71566 OD was 13 minutes. After multiple attempts a 4.5 mm silicone plug was placed under the stretched capsulorrhexis and 0.3 cc of the polysiloxane polymer material was injected into the capsule bag. Slit lamp biomicroscopy was performed on Days 0, 1, 7, 15, 18, 26, 44, 74 and 107.
Immediately postoperative, all wounds were intact. Trace conjunctival injection, corneal haze and edema were noted at day 1 which resolved by one week. Trace anterior chamber flare was seen at day 1-5 which resolved by 2 weeks. Mild posterior synechiae to the capsulorrhexis was seen in all eyes. Severe synechiae was noted in one eye at days 7-26. The anterior capsulorrhexis was sealed by the 4.5 mm silicone plug and/or the Acuvue contact lens throughout the study, except in 2 eyes. In rabbit eye 71719 OS (SI-40 IOL) the polysiloxane polymer material and SI40NB IOL was noted to extrude into the anterior chamber at Day 26.
In two separate eyes a SI40NB IOL or an Acuvue contact lens were placed intracapsularly prior to injection of the polysiloxane polymer material. The SI40NB IOL was noted to rest against the posterior capsule and was associated with trace anterior and posterior capsule haze immediately postoperative. As time progressed the polysiloxane polymer material and the SI40NB IOL were extruded into the anterior chamber for no apparent reason. The Acuvue® contact lens was noted to rest against the clear anterior capsule for the two month follow-up period. It is of note that the Acuvue®/polysiloxane polymer material eye had the only clear anterior capsule (devoid of haze, striae or folds) in the 3 studies (see
Three year old large rabbits have a large lens with a nuclear density estimated to be 3-4+. These lenses are thought to be very similar to the adult cataractous lens with a 3-4+ nuclear density. In this study, the hard lens was able to be removed through a 2.0 mm capsulorrhexis using a 21 gauge Shark Tooth Phaco needle. However, the phaco time was exceedingly long, averaging from 13 to 20 minutes. It is important to note that these lenses were much larger than the human lens (maybe as much as twice the size of the human lens) and therefore one would anticipate being able to reduce the total phaco time to 5 to 10 minutes in the human eye.
This study evaluated the implantation of an Acuvue® contact lens in combination with the polysiloxane polymer material. The New Zealand white female rabbit (Rabbit 71891) was about 3-4 months old at time of surgery and weighed 2.6 kg.
Rabbit 71891 OD, OS: Uneventful endocapsular lens extractions were performed through a 2.0 (OD) to 2.5 mm (OS) capsulorrhexis using a 20 gauge phaco needle with Healon 5® brand hyaluronic acid for anterior chamber maintenance. During phaco the capsulorrhexis stretched and a 4.5 mm silicone plug was positioned under the capsulorrhexis. In the right eye, an Acuvue® contact lens was cut to 6.5 mm and placed into the capsule bag with forceps. The polysiloxane polymer material (0.25 cc) was then injected under the contact lens which assisted the silicone plug in preventing polysiloxane polymer leakage. In the left eye, the polysiloxane polymer material (0.15 cc) was injected into the capsule bag with slight leakage.
Slit lamp biomicroscopy was performed Days 0, 21, 38 and 53. Immediately postoperative, all wounds were intact. Trace to mild corneal haze and edema were noted day 1 and resolved by one week.
Example 1c was designed to quantitate the amount of polysiloxane polymer material required to fill the capsule bag of 3 month old New Zealand white rabbits. The rabbits used in this study were 3-4 months old and weighed 2.5-2.6 kg.
Rabbits 72823 OD, 72824 OD, 72825 OD: Uneventful endocapsular lens extractions were performed through a 3.0 capsulorrhexis using a 21 gauge phaco needle with Healon 5® brand hyaluronic acid for anterior chamber maintenance. A 4.5 mm silicone plug was placed into the capsular bag and 0.2 cc, 0.1 cc and 0.2 cc of the polysiloxane polymer material was injected into the capsule bag of rabbit 72823 OD, 72824 OD and 72825 OD, respectfully. Minimal air bubbles and polysiloxane polymer leakage were noted. Slit lamp biomicroscopy was performed on Days 0, 5, 26 and 57.
Immediately postoperative, all wounds were intact. Trace anterior chamber flare was seen at day 1-5 which resolved by 2 weeks. Mild anterior chamber fibrin was noted in one eye at day 1 and a small polysiloxane polymer material bubble was seen in one eye. In rabbit 72824 OD the silicone plug and polysiloxane polymer material also protruded into the anterior chamber at day 26.
Immediately postoperative, the capsule bags were clear and distended with the clear polysiloxane polymer material. The polysiloxane polymer material used remained clear in all studies throughout the follow-up period (for as long as 107 days). Underfilling of the capsule bag was noted in some eyes. In particular, 0.1 cc of the polysiloxane polymer material was not enough to fill the capsule bag and was associated with slippage of the silicone plug and extrusion of polysiloxane polymer material into the anterior chamber. Rather, about 0.2 cc of polysiloxane polymer material was required to fill the capsule bag of these 3-4 months old New Zealand white rabbits, weighing 2.5-2.6 kg.
Immediately postoperative, trace posterior capsule haze was noted in most eyes and gradually progressed with striae and folds also noted. Posterior capsule lens regrowth was first noted at day 26 and gradually progressed surrounding the polysiloxane polymer material. In general lens regrowth was clear anterior and peripheral to the polysiloxane polymer material and more irregular and opaque posterior to the polysiloxane polymer material. By one week varying degrees of anterior capsule haze, striae and folds were noted in all eyes except the one eye with the Acuvue® lens against the anterior capsule (
In summary, the results of the described studies indicated that: (i) endocapsular lens extraction could be performed through a small 2.0 mm capsulorrhexis in the hard lens (3-4+) of 3 year old large rabbits; (ii) a clear anterior capsule devoid of haze, striae or folds was noted in the one eye with the Acuvue® contact lens positioned between the anterior capsule and polysiloxane polymer material; (iii) the polysiloxane polymer material was an intralenticular lens with clear regenerative lens material surrounding it, thus creating a bilenticular lens; and (iv) the 3-4 month old rabbit requires about 0.2 cc of the polysiloxane polymer material to fill the capsule bag.
The following in vivo study was designed to evaluate lens regeneration with a polysiloxane polymer material as a flexible and biocompatible polymeric scaffold for lens regeneration following endocapsular lens extraction with and without the injection of additional biodegradable materials.
The polysiloxane polymer material used in the presently described study was obtained from AMO Groningen B.V. (Groningen, Holland) and corresponded to composition AS4-11, CS0402014. Silicone plugs (2.7 mm and 4.5 mm) were also obtained from AMO Groningen B.V. (Groningen, Holland). Healon® brand hyaluronic acid and Healon 5® brand hyaluronic acid were obtained from AMO USA, Inc. (Santa Ana, Calif., USA).
Six three-month old female New Zealand white rabbits weighing about 2.5-2.6 kg at the time of surgery were used. The general health and acceptability of the animals was established prior to surgery. Animals were treated in accordance with USDA guidelines and the ARVO Resolution on the Use of Animals in Research.
Rabbits were anesthetized with about 5 mg/kg xylazine and about 50 mg/kg ketamine HCl, intramuscularly. The surgical eye was dilated with 1% cyclopentolate and 10% phenylephrine; eyelashes were trimmed; and the ocular area was disinfected with povidone iodine. A wire lid speculum was inserted to retract the lids, and a corneal incision was made at 12:00 with a 2.85 mm keratome. Healon 5® brand hyaluronic acid was injected to maintain anterior chamber depth and an about 2-3 mm continuous curvilinear capsulorrhexis was performed. A 20 gauge phacoemulsification tip was inserted through the corneal wound and endocapsular lens extraction was performed by phacoemulsification and irrigation/aspiration with balanced salt solution (BSS). Considerable care was taken to remove all lens cortical material by diligent irrigation and aspiration. A 2.7 mm or 4.5 mm silicone plug was inserted into the capsule bag and maneuvered behind the anterior capsulotomy. In one eye following lens extraction, Healon® brand hyaluronic acid was injected into the capsule bag to coat the anterior and posterior capsule followed by injection of the polysiloxane polymer material. In the opposite eye, the Healon® brand hyaluronic acid was not administered and the polysiloxane polymer material alone was injected into the empty capsule bag using a 20 gauge cannula. About 0.07 cc to about 0.14 cc of the polysiloxane polymer material was injected into the capsule bag of the rabbits. Minimal air bubbles and polysiloxane polymer leakage were noted during administration.
In rabbit eye #74718 OD, epinephrine was added to the balanced salt solution to increase dilation. In rabbit eye #74717 OS, the capsulorrhexis stretched during phacoemulsification and a double patch consisting of a 4.5 mm silicone plug and a 24 hour collagen patch was placed in this eye. A 4.5 mm silicone plug was placed in rabbit eye #74719 to seal the capsulotomy. In one Healon® HA/polysiloxane polymer rabbit eye, #74725 OD, the polysiloxane polymer material leaked into the anterior chamber. The Healon® brand hyaluronic acid was injected after polysiloxane polymer material leaked out and before new polysiloxane polymer material was re-injected.
At the completion of these surgical procedures, corneal incisions were closed with 10-0 nylon sutures. 0.25 ml (20 mg) of gentamicin and 0.1 ml of dexamethasone (2 mg) was injected subconjunctivally at the end of each surgery and every 3 days thereafter for two weeks.
Slit lamp biomicroscopy was performed on: Day 0, 2, 15, 20, 29, 42 and 50. The overall positional stability of the silicone plug was evaluated based on the slit lamp observation of placement in the capsule bag. Observations of conjunctiva, corneal pathology, anterior chamber cells, flare and fibrin, posterior synechiae, capsular bag shape, and percent lens regrowth in the capsule bag were recorded. All slit lamp findings were graded on a scale of 0 to 4 (0=none, 1+=trace, 2+=mild, 3+=moderate, 4+=severe) as described in further detail in Example 1. Further, throughout the experimental period, rabbits were observed for any abnormal clinical signs, including any abnormal ocular findings such as pain, excessive hyperemia or discharge. All observations were recorded on the Slit Lamp Examination form. Grading for corneal edema/cloudiness; cells in the anterior chamber; anterior chamber flare; fibrin in the anterior chamber; and posterior synechia was performed as described in relation to Example 1.
At the end of the study, animals were euthanized by an injection of sodium pentobarbital into the marginal ear vein. Rabbit eyes 74717 OU and 74718 OU had the polysiloxane polymer material removed surgically before all eyes were placed in formalin.
Immediately postoperative, all wounds were intact. Conjunctival injection, corneal edema and haze, anterior chamber cells and flare and anterior chamber fibrin were mild and similar in both groups. Mean conjunctival scores were 0.8±0.4 and 1.0±0.8, mean corneal edema and haze scores were 0.8±0.4 and 0.7±0.4, mean anterior chamber cell scores were 0.3±0.5 and 0.2±0.4, mean flare scores were 1.2±0.4 and 1.0±0.6 and mean anterior chamber fibrin scores were 1.2±0.4 and 0.5±0.5 in the polysiloxane polymer and Healon® HA/polysiloxane polymer groups, respectfully. All inflammatory signs resolved by day 15. One eye in the Healon® HA/polysiloxane polymer group had a drop of silicone material in the anterior chamber. Relevant results are summarized in the following tables:
As can be seen in the following tables, trace posterior synechiae was first noted at day 2 in 5 of the 6 eyes in both groups and gradually diminished by the end of the study at day 50:
Mean capsulorrhexis size was 1.9±0.2 in the polysiloxane polymer group and 2.3±0.5 in the Healon® HA/polysiloxane polymer group. Immediately postoperative, the anterior capsulotomy was sealed by the silicone plug in all eyes and the collagen patch in the one eye of the Healon® HA/polysiloxane polymer group. The anterior capsulotomies remained closed in all eyes throughout the study.
Immediately postoperative, the capsule bags were distended with the polysiloxane polymer material. The clear polysiloxane polymer material filled about 60% to about 100% of the capsule bag in the polysiloxane polymer (
Immediately postoperative at day 5, the anterior capsule was clear in all eyes in both groups. By day 15, mild to moderate fibrosis was seen in all eyes in the polysiloxane polymer only group. Fibrosis remained stable in 4 of 6 eyes and gradually progressed to moderate in 2 eyes (
Lens regrowth was first noted in one eye each at day 20 in the polysiloxane polymer group and at day 15 in the Healon® HA/polysiloxane polymer group. By day 42, 5 to 10% lens regrowth was noted in all eyes in the polysiloxane polymer group and 5 to 20% lens regrowth was noted in the Healon® HA/polysiloxane polymer group. In both groups lens regrowth was generally clear in the peripheral capsule bag and more opacified posterior to the polysiloxane polymer material. Lens regrowth was clear in 2 eyes (
The study described in Example 2 was designed to evaluate lens regeneration with polysiloxane polymer material as a flexible and biocompatible polymeric lens following endocapsular lens extraction in young New Zealand white rabbits with or without the inclusion of an additional biocompatible material. Overall the inflammatory response to lens extraction and polysiloxane polymer injection was mild and resolved by the second postoperative visit at 2 weeks in both groups. Mild posterior synechiae to the capsulotomy site gradually diminished and the anterior capsulotomy remained closed throughout the study.
About 0.1 to 0.14 cc of the clear polysiloxane polymer material was required to completely fill the capsule bag. Immediately postoperative, the capsule bag and polysiloxane polymer material were clear in all eyes in both groups. By the second examination at 2 weeks, anterior capsule fibrosis was noted in all eyes in the polysiloxane polymer only group. The fibrosis remained stable in 4 eyes and gradually increased in 2 eyes, In contrast the anterior capsule remained clear in 4 eyes in the Healon® HA/polysiloxane polymer group. This suggests that the Healon® brand hyaluronic acid may have an antifibrotic effect and may also prevent contact between the polymer and the capsule.
Peripheral and posterior capsule lens regrowth surrounding the polysiloxane polymer material was first noted in one eye at day 20 in the polysiloxane polymer group and at day 15 in the Healon® HA/polysiloxane polymer group. Lens regrowth gradually developed in all eyes by day 42 and was generally clear in the peripheral capsule bag and more opacified posterior to the polysiloxane polymer material. The full development of lens regeneration around the polysiloxane polymer material was limited by the early termination of the study for administrative reasons.
Thus, in the described study, limited lens regeneration was observed as early as 15 days surrounding the polysiloxane polymer material scaffold following endocapsular lens extraction in 3 month old New Zealand white rabbits. Overall lens regrowth was clear anterior and in the periphery and slightly opaque posterior the polysiloxane polymer material. The administration of Healon® brand hyaluronic acid prior to injection of the polysiloxane polymer material was associated with significantly less anterior capsule fibrosis.
In one embodiment of the polysiloxane polymers used in accordance with the present invention, the polysiloxane polymer has functional acryl groups that can be obtained from a polymer having the general formula:
wherein R1 and R2 are independently C1-C6 alkyl; R3 is phenyl; R4 is phenyl or C1-C6 alkyl; R5 is CF3(CH2)x wherein x is 1-5; R6 is C1-C6 alkyl or fluoroalkyl; 1 is in the molar fraction range of 0 to 0.95; m is in the molar fraction range of 0 to 0.7; and n is in the molar fraction range of 0 to 0.65, the polymer having functional acryl groups at the terminal ends thereof. In one embodiment, m is in the molar fraction range of from greater than 0 to 0.7; and n is in the molar fraction range of from greater than 0 to 0.65.
In another embodiment R1 is methyl, that R2 is methyl, R4 is phenyl, that x is 2, either independently, or in combination.
According to these alternatives, in one embodiment R6 is methyl. According to another embodiment, the polysiloxane is a polymer of diphenyl or phenylalkyl siloxane and dialkyl siloxane with terminal acryl groups. According to further embodiments, the polysiloxane is a polymer of diphenyl or phenylalkyl siloxane and trifluoroalkyl(alkyl)siloxane, or a terpolymer or higher order polymer of diphenyl and/or phenylalkyl siloxane, dialkyl siloxane and trifluoroalkyl alkyl siloxane. According to another embodiment, polysiloxane is an acryl-terminated terpolymer of dimethyl siloxane, diphenyl siloxane or phenylmethyl siloxane and 3,3,3-trifluoropropylmethyl siloxane. In certain embodiments the polysiloxanes comprise at least about 4 mol % of trifluoropropylmethyl siloxane and about 1 to about 50 mol % of diphenylsiloxane and/or phenylmethylsiloxane. In other embodiments the polysiloxanes comprise about 4 to about 65 mol % trifluoropropylmethyl siloxane, and about 1 to about 50 mol % of diphenylsiloxaue and dimethylsiloxane monomer units. One suitable acryl-terminated polysiloxane composition comprises about 28 mol % trifluoropropylmethyl siloxane, about 4 mol % diphenyl siloxane and dimethyl siloxane monomer units.
As should be understood by one of ordinary skill in the art, polymers used in accordance with the present invention can comprise any polymer that is suitable for use as a lens material. Polysiloxane polymers used in accordance with the present invention are formed into an injectable lens material having a suitable viscosity to be injected through standard cannula with an 18 Gauge needle or finer. For this purpose the material generally will have a viscosity lower than about 60000 cSt or below about 8000 cSt for being readily injectable through a 21 Gauge needle. Injectable lens materials used in accordance with the present invention can also optionally comprise a photoinitiator and/or a crosslinking agent, which itself can be siloxane oligomer or polymer having functional groups and further physiologically or ophthalmologically acceptable additives necessary for producing a lens.
A method of the in vivo production of an IOL, can comprise the steps of preparing an polysiloxane polymer having functional acryl groups; mixing the polymer and a photoinitiator, in one embodiment a medically acceptable blue light photoinitiator, into a composition; injecting the composition into the capsular bag of the eye; and initiating a polymerization reaction to create a lens in the capsular bag. Optionally, the elastomer can also comprise an UV absorbing compound or other conventional additives known to those skilled in the art. A special advantage of the materials used in accordance with the present invention is that the incorporation of a fluoroalkyl siloxane enables materials of high specific gravity to be produced
Examples of specific procedures for creating polysiloxane polymers useful in accordance with the present invention can be found in U.S. Pat. No. 6,737,496 which is incorporated by reference herein for all that it teaches regarding creating polysiloxane polymers.
As suggested by Example 2, hyaluronic acid can also be administered in conjunction with the polymers used in accordance with the present invention. Administration of hyaluronic acid can be beneficial in wound healing. Further, fetal wounds that heal without scar formation have an extracellular matrix that is rich in hyaluronic acid. In one embodiment of the present invention, a viscoelastic substance such as hyaluronic acid may be used in conjunction with a polymer (in one embodiment a polysiloxane polymer) for capsule bag filling to enhance the regeneration of lenses following phacoemulsification and subsequent irrigation and aspiration of both the natural and cataractous lens and sealing of the anterior capsule. One skilled in the art will readily appreciate that hyaluronic acid compositions of varying viscosity, glycosaminoglycans (GAG's), and/or formulations thereof may be used in accordance with alternate embodiments of the present invention. By way of example, and not of limitation, suitable hyaluronic compositions may include, but are not limited to the following: Restylane® OVD, Perlane® OVD, a variant formulation of Healon® OVD (AMO USA, Inc., Santa Ana, Calif.), and/or compositions that include hyaluronic acid forms such as those described in U.S. Pat. Nos. 6,537,795; 6,090,596; 4,764,360; 6,086,597; 6,368,585; and 5,681,825; U.S. Patent Application Publication No. 2002/0018898 (Ser. No. 09/855,923), and in European Patent Application 0760863 B1, all of which are incorporated herein by reference in their entirety as if fully set forth. Any variant formulation or analogous composition of any of the aforementioned hyaluronic compounds and/or GAGs including, but not limited to hyaluronic acid forms with higher or lower molecular weights, hyaluronic acid forms at variant concentrations, chondroitin sulfate, a hyaluronic acid/chondroitin sulfate mixture, combinations of two or more of the above mentioned compositions, and/or combinations of any of the aforementioned compositions with other suitable agents may be used in accordance with alternate embodiments of the invention. Furthermore, inventive compositions may include a hyaluronic acid compound as well as any number of conventional carriers, additives, preservatives, antibiotics, therapeutic agents and the like that are generally formulated in pharmacological compositions of this nature, as will be readily appreciated by those of skill in the art. Such additional elements may, for example, promote the safety and/or efficacy of the inventive compound. Various quantities, molecular weights, concentrations, and/or forms of hyaluronic acid products may be used to improve the lens cell proliferation and differentiation. For example, a quantity between 0.01 to 3 cc of hyaluronic acid may be used to fill the lens capsule bag to improve the lens cell proliferation and differentiation.
In alternate embodiments, other media can be used individually or in combination to enhance the proliferation and differentiation of lens cells in accordance with the present invention; for instance, amniotic fluid, in vitro fertilization media, growth factors (e.g., BD MATRIGEL™ Basement Membrane Matrix and BD MATRIGEL™ Basement Membrane Matrix High Concentration; BD Biosciences, San Jose, Calif.), and/or other substances that can enhance or control the growth and proliferation of cells will be readily appreciated by one skilled in the art.
In another embodiment, lenticular tissue may be engineered using focal laser photophacocoagulation to remove excess viscoelastic substances and/or modify structure and clarity of the regenerated lens and/or bilenticular lens. As described in U.S. Pat. No. 6,322,556 and U.S. Patent Application Publication Nos. 2002/0103478 (Ser. No. 09/953,121) and 2006/0002981 (Ser. No. 10/881,426) which are all incorporated herein by reference as if fully set forth, laser photophacoablation (laser photoablation) has been used to partially remove ocular tissue (e.g., lens tissue) to correct vision deficiencies and to treat other vision-impairing ocular problems without causing substantial damage to the surrounding tissue regions. In the present invention, laser photophacoablation may be used to remove retained viscoelastic substances in the regenerated lens in combination with the inventive use of hyaluronic acid in combination with polymers including, in certain embodiments, polysiloxane polymers.
Lens regeneration can also be enhanced in accordance with the present invention by sealing the anterior capsulotomy with one or more collagen patches. Insertion of a collagen patch may be effected during a procedure for treating ocular disease and/or correcting vision impairment, as for example, endocapsular lens extraction surgery. The lens capsule integrity is restored by inserting one or more collagen patches during endocapsular lens extraction surgery to seal the anterior capsulotomy and restore its continuity, which thereby improves the shape and structure of the regenerated lenses. It will be appreciated by those skilled in the art that a variety of collagen patches may be used and that the sealing of the capsulotomy may occur in various regions in connection with various embodiments of the present invention. For example, a collagen patch that is composed of bovine collagen type IV or a 12 hour collagen shield (Chiron Ophthalmics, Emeryville, Calif., U.S.A.) or a 24 or 72 hour PROSHIELD® Collagen Corneal Shield (Alcon Laboratories, Inc, Fort Worth, Tex.) may be used in accordance with an embodiment of the present invention. Additionally, a collagen patch may be used to seal any opening in the lens capsule bag, not just the anterior capsulotomy. Furthermore, in an alternate embodiment, injectable collagen may be used as a supplement to or a replacement for the inserted collagen patch to further enhance lens regeneration.
In an additional embodiment, collagen may be used as an internal scaffold for lens fiber cell proliferation and differentiation. A variety of collagen-based products may be used, as for example, 25% or 50% suspensions of purified bovine dermis in saline with 0.3% lidocaine (available under the trade name Zyderm I® and Zyderm II® from INAMED Corporation; Santa Barbara, Calif.), monomolecular bovine collagen suspended in solution at 3.5% and 6.5% concentrations (available under the trade name Resoplast® from Rofil Medical International; Breda, Holland), human collagen preparation comprised predominantly of intact collagen fibers as well as other matrix proteins suspended in a neutral pH buffer (available under the trade name Dermalogen® from Collagenesis Corporation; Beverly, Mass.), a cellular human dermal graft processed from tissue bank-derived skin (available under the trade name Alloderm® from LifeCell Corporation; Palo Alto, Calif.), GAG-based compound or polymer; and/or include collagen produced by amnion as described in U.S. Patent Application Publication No. 2004/0048796 (Ser. No. 10/397,867) which is incorporated by reference in its entirety as if fully set forth.
In those embodiments of the present invention directed to methods for treating ocular disease and/or correcting vision impairment, one can use these methods to treat any disease in which enhancing lens regeneration has a beneficial effect on a patient (e.g., ameliorating a disease, lessening the severity of its complications, preventing it from manifesting, preventing it from recurring, merely preventing it from worsening, or a therapeutic effort to effect any of the aforementioned, even if such therapeutic effort is ultimately unsuccessful). Methods of the present invention may be used to treat any diseases which are affected by lens tissue loss or damage, or ocular conditions or impairments which involve a medical procedure comprising the removal or alteration of lens tissue.
The present invention also includes kits. In one embodiment, the kits of the present invention comprise injectable lens materials including, in certain embodiments other materials to assist in the enhancement of lens regeneration. Kits of the present invention can contain one or more of the following in a package or container: (1) one or more injectable lens materials of the present invention; (2) one or more pharmaceutically acceptable adjuvants or excipients; (3) one or more vehicles for administration, such as one or more syringes; (4) one or more tools to use in a surgical procedure; (5) one or more additional bioactive agents for concurrent or sequential administration and/or (6) instructional information. Embodiments in which two or more of components (1)-(6) are found in the same container can also be used.
When a kit is supplied, the different components of the compositions included can be packaged in separate containers and admixed immediately before use. Such packaging of the components separately can permit long-term storage without losing the active components' functions. When more than one composition or active agent is included in a particular kit, the bioactive agents may be (1) packaged separately and admixed separately with appropriate (similar or different) vehicles immediately before use, (2) packaged together and admixed together immediately before use or (3) packaged separately and admixed together immediately before use. If the chosen compounds will remain stable after admixture, however, the admixture need not occur immediately before use but can occur at a time before use, including in one example, minutes, hours, days, months or years before use or in another embodiment at the time of manufacture.
The compositions included in particular kits of the present invention can be supplied in containers of any sort such that the life of the different components are preserved and are not adsorbed or altered by the materials of the container and/or so that other components are not damaged. For example, sealed glass ampules can contain lyophilized agents or variants or derivatives thereof or other bioactive agents, or buffers that have been packaged under a neutral, non-reacting gas, such as, without limitation, nitrogen. Ampules can consist of any suitable material, such as, without limitation, glass, organic polymers, such as, polycarbonate, polystyrene, etc., ceramic, metal or any other material typically employed to hold similar reagents. Other examples of suitable containers include, without limitation, simple bottles that may be fabricated from similar substances as ampules, and envelopes that can comprise foil-lined interiors, such as aluminum or an alloy. Other containers include, without limitation, test tubes, vials, flasks, bottles, syringes, or the like. Containers can have one or more sterile access ports, such as a bottle having a stopper that can be pierced by a hypodermic injection needle. Other containers may have two compartments that are separated by a readily removable membrane that upon removal permits the components to be mixed. Removable membranes may be, without limitation, glass, plastic, rubber, etc.
As stated earlier, kits can also be supplied with instructional materials. Instructions may be printed on paper or other substrate, and/or may be supplied as an electronic-readable medium, such as a floppy disc, CD-ROM, DVD-ROM, Zip disc, videotape, audiotape, flash memory device, etc. Detailed instructions may not be physically associated with the kit; instead, a user may be directed to an internet web site specified by the manufacturer or distributor of the kit, or supplied as electronic mail.
As should be understood, the exact formulation, route of administration, and dosage should generally be determined by the attending physician in view of the patient's condition. Dosage amount and interval can be adjusted individually to provide appropriate levels of nucleic acid molecules which are sufficient to maintain therapeutic effect.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
The terms “a” and “an” and “the” and similar referents used in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.
Certain embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
Furthermore, numerous references have been made to patents and printed publications throughout this specification. Each of the above cited references and printed publications are herein individually incorporated by reference in their entirety.
In closing, it is to be understood that the embodiments of the invention disclosed herein are illustrative of the principles of the present invention. Other modifications that may be employed are within the scope of the invention. Thus, by way of example, but not of limitation, alternative configurations of the present invention may be utilized in accordance with the teachings herein. Accordingly, the present invention is not limited to that precisely as shown and described.
The present application claims priority to U.S. Provisional Patent Application No. 60/745,825, is a continuation-in-part of U.S. patent application Ser. No. 10/881,426 filed Jun. 30, 2004, and is a continuation-in-part of U.S. patent application Ser. No. 11/293,682 filed Dec. 1, 2005 which are incorporated herein in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60745825 | Apr 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10881426 | Jun 2004 | US |
| Child | 11470724 | US | |
| Parent | 11293682 | Dec 2005 | US |
| Child | 10881426 | US |
