YAG Laser Capsulotomy - ESCRS · Aquesys implant (Aquesys Xen ®) is a permanent, flexible collagen...
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A range of implants designed to lower intraocular pressure (IOP) now under investigation could make glaucoma surgery less invasive, more predictable and more reliable, Manfred Tetz MD, of Eye Center Spreebogen and the Berlin Eye Research Institute, Berlin, Germany, told the XXX Congress of the ESCRS. Newer implants offer many approaches to improving outflow, including enhancing canal surgery, filtering surgery and uveoscleral outflow. They are made from plastic, metal or collagen, and some are delivered ab interno and others ab externo. “One thing they have in common is trying to standardise the current approach for lowering IOP and make the outcome more predictable. We will have to see in the future if that is successful.” Bypassing trabecular meshwork The iStent (Glaukos) is a titanium microshunt inserted ab interno into Schlemm’s canal through a 1.5mm corneal incision. It is designed to enhance the natural outflow mechanism by bypassing the trabecular meshwork, which is the area of highest resistance, Prof Tetz said. The initial design has established a record for effectively lowering IOP for two years or more, with initial one-year results lowering mean pressure from 21.7 mmHg to 17.4 mmHg while reducing topical medications by 1.2 average at 12 months, Prof Tetz noted. “It didn’t get to the low teens, but a significant reduction of IOP is shown in the original study of this device.” Newer generations of the implant resemble a collar button more than an angled tube, Prof Tetz said. He believes the newer designs may work better, especially if they are placed near large collector channels in the canal. Citing the work of Robert Stegmann MD, he noted that surgery doesn’t just bypass the meshwork it also opens the canal for partial circumferential flow. “You need to be in the vicinity of a collector that functions. If you are too far away, the canal may be collapsed in the intermediate pathway.” Prof Tetz cited one patient in whom he implanted two iStents in a patient failing two-medication therapy with a pre-op IOP of 25 mmHg. At one year average pressure was in the 14 mmHg range with one medication, which is much better than the original with one implant.” The Stegmann canal expander (Grieshaber Ophthalmic Research) is a perforated polyimide implant inserted ab externo into Schlemm’s canal during viscocanalostomy. Since it is implanted from the outside it can be visualised directly during insertion, Prof Tetz said. The tube functions as a scaffold, keeping the canal open and allowing aqueous to flow in from the trabecular meshwork and out to collector channels. Prof Tetz has placed more than 65 expanders, mostly in patients who have failed trabeculectomies. In one series of 10 patients, mean preoperative IOP dropped from 24.8 mmHg to 15 to 16 mmHg one, two and three months after surgery. “For failed eyes the postoperative pressure of 15 mmHg was quite satisfactory and continues in this range with these problem eyes. We will now try it in virgin eyes and see how the pressure responds.” The Hydrus intracanicular implant (Ivantis), is an 8.0mm long nickel-titanium scaffolding placed ab interno into Schlemm’s canal using an injector visualised with gonioscopy. The device also holds open the canal, allowing aqueous to pass through. Prof Tetz is currently involved in a 12-month multicentre trial using the Hydrus in 69 patients with and without cataract surgery. At six months, the cataract surgery group has seen mean pressures drop from 21.1 mmHg with 2.1 medications to 15.6 mmHg with 0.4 mean medications. Patients without concurrent cataract surgery saw pressures drop from a mean 21.6 mmHg with 1.7 meds before surgery to 16.9 mmHg and 0.6 meds at six months. Subconjunctival filtering The AqueSys implant (Aquesys Xen ®) is a permanent, flexible collagen tube inserted ab interno with an injector from the anterior chamber through the trabecular meshwork into the subconjunctival space. It creates a drainage channel without touching the external conjunctiva, greatly reducing filtration surgical trauma. The implant is also flexible when hydrated and removable, but will not move when in place, Prof Tetz said. Gonioscopy is not required since the insertion can be made anywhere in the vicinity of the meshwork. The first study, involving 107 patients observed for 30 months, is under way. Over time patients have seen a 30 per cent reduction in IOP and reduction of meds of more than one-half. Some changes have been made to the implant and the injector during the course of the study, and some patients have received injections of anti- metabolites, but these are not unusual for trabeculectomy, he noted. The Gold Shunt (Solx), is a 2.0mm by 6.0mm gold device inserted through a pocket incision in the cornea, with one end in the anterior chamber and the other inserted into the suprachoroidal space. “Gold was chosen because it is fairly inert. However, it is fibrin active and can cause inflammation,” said Alan Crandall MD, of the Moran Eye Center, University of Utah, Salt Lake City, US. As a result, the device often is encapsulated and must be removed, he added. Movement may exacerbate the problem. A new design is inserted 4-5mm posteriorly and sits in a pocket in the suprachoroidal space. The CyPass Micro-Stent (Transcend Medical, Menlo Park, California, US) is a 6.5mm tube constructed of non-degradable polyimide material that has been used in implants for years, Dr Crandall said. It is inserted in the supraciliary space to increase suprachoroidal outflow. “The initial data are quite good,” Dr Crandall said. Patients have maintained a 30 per cent drop in IOP for over a year, and the device is easily implantable during cataract surgery. IOP-LOWERING Minimally invasive devices have much to offer in the future by Howard Larkin in Milan EUROTIMES | Volume 18 | Issue 4 Manfred Tetz – [email protected] Alan Crandall – [email protected] contacts YAG Laser Capsulotomy ... you are just one step away: http://yag-laser.arclaser.de Laser and Slit Lamp Perfection is all that counts. 21 Update GLAUCOMA It didn’t get to the low teens, but a significant reduction of IOP is shown in the original study of this device “ Manfred Tetz MD
Transcript of YAG Laser Capsulotomy - ESCRS · Aquesys implant (Aquesys Xen ®) is a permanent, flexible collagen...
A range of implants designed to lower intraocular pressure (iOP) now under investigation could make glaucoma surgery
less invasive, more predictable and more reliable, Manfred Tetz MD, of Eye Center spreebogen and the Berlin Eye Research institute, Berlin, Germany, told the XXX Congress of the EsCRs. Newer implants offer many approaches to improving outflow, including enhancing canal surgery, filtering surgery and uveoscleral outflow. They are made from plastic, metal or collagen, and some are delivered ab interno and others ab externo.
“One thing they have in common is trying to standardise the current approach for lowering iOP and make the outcome more predictable. We will have to see in the future if that is successful.”
Bypassing trabecular meshwork The istent (Glaukos) is a titanium microshunt inserted ab interno into schlemm’s canal through a 1.5mm corneal incision. it is designed to enhance the natural outflow mechanism by bypassing the trabecular meshwork, which is the area of highest resistance, Prof Tetz said.
The initial design has established a record for effectively lowering iOP for two years or more, with initial one-year results lowering mean pressure from 21.7 mmhg to 17.4 mmhg while reducing topical medications by 1.2 average at 12 months, Prof Tetz noted.
“it didn’t get to the low teens, but a significant reduction of iOP is shown in the original study of this device.”
Newer generations of the implant resemble a collar button more than an angled tube, Prof Tetz said. he believes the newer designs may work better, especially if they are placed near large collector channels in the canal. Citing the work of Robert stegmann MD, he noted that surgery doesn’t just bypass the meshwork it also opens the canal for partial circumferential flow.
“You need to be in the vicinity of a collector that functions. if you are too far away, the canal may be collapsed in the intermediate pathway.”
Prof Tetz cited one patient in whom he implanted two istents in a patient failing two-medication therapy with a pre-op iOP of 25 mmhg. At one year average pressure was in the 14 mmhg range with one medication, which is much better than the original with one implant.”
The stegmann canal expander (Grieshaber Ophthalmic Research) is a perforated polyimide implant inserted ab externo into schlemm’s canal during viscocanalostomy. since it is implanted from the outside it can be visualised directly during insertion, Prof Tetz said. The tube functions as a scaffold, keeping the canal open and allowing aqueous to flow in from the trabecular meshwork and out to collector channels.
Prof Tetz has placed more than 65 expanders, mostly in patients who have
failed trabeculectomies. in one series of 10 patients, mean preoperative iOP dropped from 24.8 mmhg to 15 to 16 mmhg one, two and three months after surgery.
“For failed eyes the postoperative pressure of 15 mmhg was quite satisfactory and continues in this range with these problem eyes. We will now try it in virgin eyes and see how the pressure responds.”
The hydrus intracanicular implant (ivantis), is an 8.0mm long nickel-titanium scaffolding placed ab interno into schlemm’s canal using an injector visualised with gonioscopy. The device also holds open the canal, allowing aqueous to pass through.
Prof Tetz is currently involved in a 12-month multicentre trial using the hydrus in 69 patients with and without cataract surgery. At six months, the cataract surgery group has seen mean pressures drop from 21.1 mmhg with 2.1 medications to 15.6 mmhg with 0.4 mean medications. Patients without concurrent cataract surgery saw pressures drop from a mean 21.6 mmhg with 1.7 meds before surgery to 16.9 mmhg and 0.6 meds at six months.
Subconjunctival filtering The Aquesys implant (Aquesys Xen ®) is a permanent, flexible collagen tube inserted ab interno with an injector from the anterior chamber through the trabecular meshwork into the subconjunctival space. it creates
a drainage channel without touching the external conjunctiva, greatly reducing filtration surgical trauma. The implant is also flexible when hydrated and removable, but will not move when in place, Prof Tetz said. Gonioscopy is not required since the insertion can be made anywhere in the vicinity of the meshwork.
The first study, involving 107 patients observed for 30 months, is under way. Over time patients have seen a 30 per cent reduction in iOP and reduction of meds of more than one-half. some changes have been made to the implant and the injector during the course of the study, and some patients have received injections of anti-metabolites, but these are not unusual for trabeculectomy, he noted.
The Gold shunt (solx), is a 2.0mm by 6.0mm gold device inserted through a pocket incision in the cornea, with one end in the anterior chamber and the other inserted into the suprachoroidal space.
“Gold was chosen because it is fairly inert. however, it is fibrin active and can cause inflammation,” said Alan Crandall MD, of the Moran Eye Center, University of Utah, salt Lake City, Us. As a result, the device often is encapsulated and must be removed, he added. Movement may exacerbate the problem.
A new design is inserted 4-5mm posteriorly and sits in a pocket in the suprachoroidal space.
The CyPass Micro-stent (Transcend Medical, Menlo Park, California, Us) is a 6.5mm tube constructed of non-degradable polyimide material that has been used in implants for years, Dr Crandall said. it is inserted in the supraciliary space to increase suprachoroidal outflow.
“The initial data are quite good,” Dr Crandall said. Patients have maintained a 30 per cent drop in iOP for over a year, and the device is easily implantable during cataract surgery.
IOP-lOWERINGMinimally invasive devices have much to offer in the futureby Howard Larkin in Milan
EUROTIMES | Volume 18 | Issue 4
Manfred Tetz – [email protected] Crandall – [email protected]
cont
acts
YAG Laser Capsulotomy
... you are just one step away:http://yag-laser.arclaser.de
Laser and Slit Lamp Perfection is all that counts.
21Update
GLAUCOMA
It didn’t get to the low teens, but a significant reduction of IOP is shown in the original study of this device
“Manfred Tetz MD
