Somebody asked me about this. Apparently it is a non-invasive mechanical method for increasing aqueous outflow. Anybody ever hear of this? I checked the website coronadoindustries.com and found it mildly interesting. I gave it a thumbs down (for several reasons), but I wanted to hear some other opinions. Thanks
Pneumatic trabeculoplasty??
- Thread starter PBEA
- Start date
- Joined
- Oct 1, 2002
- Messages
- 5,633
- Reaction score
- 20
http://www.quackwatch.org/06ResearchProjects/pnt.html
Pneumatic Trabeculoplasty (PNT) for Glaucoma
Stephen Barrett, M.D.
In 1997, the Arizona Glaucoma Institute (AGI), of Scottsdale, Arizona, began offering a "new treatment" for open-angle and pigmentary glaucoma using a patented vacuum-ring device. Devices of this type are FDA-approved for stabilizing the eye during refractive (lens) surgery, but they are not approved for use in treating glaucoma. The institute's parent company, Coronado Industries, marketed the device through another subsidiary called Ophthalmic International. Patent information for the device states:
The open angle glaucoma treatment apparatus is a vacuum source and a vacuum applicator coupled by a hose. The vacuum applicator is an eye ring or an eye cup that is placed on the frontal surface of an eye. Suction (negative pressure) in the range of 10 to 30 mm. Hg. is applied by the vacuum source, which will fixure the ring or cup to the eye, or alternatively pressure is applied for 15 to 120 seconds. A second treatment is recommended later. It could be within twelve hours, on the following day, or within the next couple of days [2].
An AGI brochure stated that a 2-minute treatment with the device "lowers intra-ocular pressure in most cases." [3] Another institute document states that during the previous four years, "a good number" of patients have been taken off of their medication completely and that "a number of patients" have remained on medication but required reduced dosage [4]. PNT costs about $200 per treatment. In September 1997, the institute offered free glaucoma screenings in connection with its"grand opening." [5]
In early 1998, an Arizona investment firm seeking investors for Coronado Industries issued a private offering summary which noted that the AGI's medical director, ophthalmologist Leo D. Bores, M.D., had originated the radial keratotomy procedure [6]. The solicitation, intended "for broker-dealer internal use only," projects after-tax earnings of $12 million in 1998, $46 million in 1999, and $99 million in the year 2000. The solicitation also states that the proceeds will be used to open additional Glaucoma Treatment Centers and that Coronado Industries believes that "insurance companies will . . . quickly approve payment for the new device and procedure since it is projected to reduce the cost of long-term care costs associated with alternative treatments." [6] However, the company's Form SB-2 Registration Statement filed with the Securities and Exchange Commission on 8/24/98, noted receipts of $179,767 and an overall loss of $648,702 for the first half of 1998 [7]. The report also stated:
In March 1998, the company's Scottsdale treatment center began receiving Medicare payments for . . . the PNT procedure. There is no assurance that these payments will continue . . . and as to when, if ever, the Company will receive payments at . . . additional centers from third-party payors [7].
Safety and Effectiveness Questioned
The fluid within the eyeball normally drains through the trabecular meshwork, a thin net-like band that lies between between the cornea (the clear window of the eye) and the sclera (the white portion of the eye). Glaucoma usually occurs because the mesh becomes clogged or is unable to allow sufficent drainage. When this happens, since fluid production continues, intraocular pressure builds up.
Normal eye pressures range from 8 to 20 millimeters of mercury (mm Hg). In high-pressure glaucoma, the levels range from 21 to 40. In rare cases, new patients present with higher levels. The higher the pressure, the more likely that optic nerve damage will occur. PNT is postulated to reduce pressure within the eye by squeezing fluid out through the trabecular meshwork. However, fluid production continues, so unless the procedure can improve the drainage system itself, any pressure reduction would be short-lived.
PNT temporarily squeezes the front of the eyeball and raises the intraocular pressure to 65 and perhaps even higher. In someone with an already damaged optic nerve, this could be serious. The accepted treatment for glaucoma is to lower the pressure with medication or surgery. Experiments in monkeys have demonstrated that sudden pressure elevations can compromise the blood supply to the optic nerve and accelerate nerve cell death in already weakened cells [8,9], and human experiments have found that acute pressure increases can increase cupping of the optic nerve [10,11]. Two cases have been reported of patients who lost part of their vision following LASIK operations during which their intraocular pressure was temporarily raised when a suction ring was applied to their eyeball [12,13]. For these reasons, until proven safe, PNT should be viewed with caution. Damage from high intraocular pressure may not be immediately apparent. As a result, patients having PNT may not be able to tell whether they are being harmed until it is too late to reverse the damage. Proof of safety and effectiveness would require long-term studies showing not only that intraocular pressure is lowered, but also that the patients' visual fields have not been adversely affected.
To date, no peer-reviewed journal has published a study demonstrating that PNT actually works or is safe. Preliminary reports by Dr. Bores, a Mexican ophthalmologist (Guillermo Avalos, M.D.), and ophthalmologist John LiVecchi, M.D. (described in the brochure as a director and major shareholder of Coronado Industries) have claimed positive results. A report on Coronado Industries' Web site in November 1998 stated that at least 250 patients had been treated for up to 3.5 years, with "maintenance therapy as frequently as every 2-3 months to yearly." These reports claimed various levels of effectiveness, with the drop in pressure being greatest in people whose problem was least severe when they sought treatment. However, a study conducted at the Duke University School of Medicine found that PNT did not lower intraocular pressure among 20 patients with uncontrolled glaucoma. Each patient had one eye treated while the other served as a control. Measurements at one hour, two hours, one day, one week, one month, and three months later found no reduction of intraocular pressure or improvement in the drainage of fluid from within the eye [14]. The reports from Drs. Bores, Avelos, and LaVecchi did not contain such comparative data or compare their patients to a control group of similar patients who did not undergo PNT.
FDA Objections
Documents obtained with a Freedom of Information Act request indicate that in February 1998, the FDA issued a warning letter to Ophthalmic International president G. Richard Smith. The letter stated:
During an inspection of your firm conducted between November 25 and December 11, 1997, our investigators determined that your firm distributed two vacuum fixation devices with suction rings to the Arizona Glaucoma Institute. . . for use in treating patients with glaucoma using a pneumatic trabeculoplasty (PNT) procedure. These products are devices as defined by . . . the Federal Food, Drug, and Cosmetic Act.
Your vacuum fixation devices are adulterated . . . in that they are Class III devices. . . and do not have approved applications for investigational device exemption (IDE). . . . Your . . . devices are also misbranded . . . in that a notice or other information respecting the devices was not provided to the FDA as required [15].
The letter indicated that because the device is not approved for the treatment of glaucoma, the FDA regards it as a new device for which FDA approval is required and that:
The sponsors of investigations, investigators, or any persons acting for or on behalf of a sponsor or an investigator may not promote or test market an investigational device or represent that it is safe or effective for the purpose for which it is being investigated.
Smith replied that the vacuum fixation device does have an IDE and should not be considered a Class III device, that an Institutional Review Board (IRB) had determined that the device did not pose an unreasonable risk to patients, and that his company plans to submit an application to broaden the way the device is used [16]. However, an FDA official responded that the device had not been formally classified, that new devices are automatically placed in Class III, and that the agency disagreed with the IRB's conclusion [17]. In August 1998, the company submitted an IDE application [7], which the FDA rejected.
Disciplinary Action
In March 1999, Dr. Bores announced that he had retired from clinical practice but would continue to direct research at the American Eye Institute, with which AGI had merged [18]. In December 1999, after additional communication with the FDA, Ophthalmic International was given permission to conduct a small "feasibility study." [19] Federal regulations state that during clinical studies, no investigator or sponsor can commercially distribute an unapproved device, charge subjects more than the amount needed to cover costs, or represent that the device is safe or effective for its intended purpose. According to information from the Arizona Medical Board, Bores did all of these things, lacked FDA approval to conduct any PNT studies, and improperly collected Medicare payments for patients treated between December 1997 and February 1999. In April 2003, the board reprimanded Bores and placed him on two years' probation under which he is barred from conducting studies that do not meet FDA criteria and must reimburse Medicare for $15,539.81 that he had been paid for the 1997-1999 treatments [19].
The Bottom Line
Pneumatic trabeculoplasty has not been proven safe or effective for treating glaucoma; and Coronado Industries' vacuum fixation device lacks FDA approval for such use. It remains to be seen whether additional research will demonstrate benefit.
Pneumatic Trabeculoplasty (PNT) for Glaucoma
Stephen Barrett, M.D.
In 1997, the Arizona Glaucoma Institute (AGI), of Scottsdale, Arizona, began offering a "new treatment" for open-angle and pigmentary glaucoma using a patented vacuum-ring device. Devices of this type are FDA-approved for stabilizing the eye during refractive (lens) surgery, but they are not approved for use in treating glaucoma. The institute's parent company, Coronado Industries, marketed the device through another subsidiary called Ophthalmic International. Patent information for the device states:
The open angle glaucoma treatment apparatus is a vacuum source and a vacuum applicator coupled by a hose. The vacuum applicator is an eye ring or an eye cup that is placed on the frontal surface of an eye. Suction (negative pressure) in the range of 10 to 30 mm. Hg. is applied by the vacuum source, which will fixure the ring or cup to the eye, or alternatively pressure is applied for 15 to 120 seconds. A second treatment is recommended later. It could be within twelve hours, on the following day, or within the next couple of days [2].
An AGI brochure stated that a 2-minute treatment with the device "lowers intra-ocular pressure in most cases." [3] Another institute document states that during the previous four years, "a good number" of patients have been taken off of their medication completely and that "a number of patients" have remained on medication but required reduced dosage [4]. PNT costs about $200 per treatment. In September 1997, the institute offered free glaucoma screenings in connection with its"grand opening." [5]
In early 1998, an Arizona investment firm seeking investors for Coronado Industries issued a private offering summary which noted that the AGI's medical director, ophthalmologist Leo D. Bores, M.D., had originated the radial keratotomy procedure [6]. The solicitation, intended "for broker-dealer internal use only," projects after-tax earnings of $12 million in 1998, $46 million in 1999, and $99 million in the year 2000. The solicitation also states that the proceeds will be used to open additional Glaucoma Treatment Centers and that Coronado Industries believes that "insurance companies will . . . quickly approve payment for the new device and procedure since it is projected to reduce the cost of long-term care costs associated with alternative treatments." [6] However, the company's Form SB-2 Registration Statement filed with the Securities and Exchange Commission on 8/24/98, noted receipts of $179,767 and an overall loss of $648,702 for the first half of 1998 [7]. The report also stated:
In March 1998, the company's Scottsdale treatment center began receiving Medicare payments for . . . the PNT procedure. There is no assurance that these payments will continue . . . and as to when, if ever, the Company will receive payments at . . . additional centers from third-party payors [7].
Safety and Effectiveness Questioned
The fluid within the eyeball normally drains through the trabecular meshwork, a thin net-like band that lies between between the cornea (the clear window of the eye) and the sclera (the white portion of the eye). Glaucoma usually occurs because the mesh becomes clogged or is unable to allow sufficent drainage. When this happens, since fluid production continues, intraocular pressure builds up.
Normal eye pressures range from 8 to 20 millimeters of mercury (mm Hg). In high-pressure glaucoma, the levels range from 21 to 40. In rare cases, new patients present with higher levels. The higher the pressure, the more likely that optic nerve damage will occur. PNT is postulated to reduce pressure within the eye by squeezing fluid out through the trabecular meshwork. However, fluid production continues, so unless the procedure can improve the drainage system itself, any pressure reduction would be short-lived.
PNT temporarily squeezes the front of the eyeball and raises the intraocular pressure to 65 and perhaps even higher. In someone with an already damaged optic nerve, this could be serious. The accepted treatment for glaucoma is to lower the pressure with medication or surgery. Experiments in monkeys have demonstrated that sudden pressure elevations can compromise the blood supply to the optic nerve and accelerate nerve cell death in already weakened cells [8,9], and human experiments have found that acute pressure increases can increase cupping of the optic nerve [10,11]. Two cases have been reported of patients who lost part of their vision following LASIK operations during which their intraocular pressure was temporarily raised when a suction ring was applied to their eyeball [12,13]. For these reasons, until proven safe, PNT should be viewed with caution. Damage from high intraocular pressure may not be immediately apparent. As a result, patients having PNT may not be able to tell whether they are being harmed until it is too late to reverse the damage. Proof of safety and effectiveness would require long-term studies showing not only that intraocular pressure is lowered, but also that the patients' visual fields have not been adversely affected.
To date, no peer-reviewed journal has published a study demonstrating that PNT actually works or is safe. Preliminary reports by Dr. Bores, a Mexican ophthalmologist (Guillermo Avalos, M.D.), and ophthalmologist John LiVecchi, M.D. (described in the brochure as a director and major shareholder of Coronado Industries) have claimed positive results. A report on Coronado Industries' Web site in November 1998 stated that at least 250 patients had been treated for up to 3.5 years, with "maintenance therapy as frequently as every 2-3 months to yearly." These reports claimed various levels of effectiveness, with the drop in pressure being greatest in people whose problem was least severe when they sought treatment. However, a study conducted at the Duke University School of Medicine found that PNT did not lower intraocular pressure among 20 patients with uncontrolled glaucoma. Each patient had one eye treated while the other served as a control. Measurements at one hour, two hours, one day, one week, one month, and three months later found no reduction of intraocular pressure or improvement in the drainage of fluid from within the eye [14]. The reports from Drs. Bores, Avelos, and LaVecchi did not contain such comparative data or compare their patients to a control group of similar patients who did not undergo PNT.
FDA Objections
Documents obtained with a Freedom of Information Act request indicate that in February 1998, the FDA issued a warning letter to Ophthalmic International president G. Richard Smith. The letter stated:
During an inspection of your firm conducted between November 25 and December 11, 1997, our investigators determined that your firm distributed two vacuum fixation devices with suction rings to the Arizona Glaucoma Institute. . . for use in treating patients with glaucoma using a pneumatic trabeculoplasty (PNT) procedure. These products are devices as defined by . . . the Federal Food, Drug, and Cosmetic Act.
Your vacuum fixation devices are adulterated . . . in that they are Class III devices. . . and do not have approved applications for investigational device exemption (IDE). . . . Your . . . devices are also misbranded . . . in that a notice or other information respecting the devices was not provided to the FDA as required [15].
The letter indicated that because the device is not approved for the treatment of glaucoma, the FDA regards it as a new device for which FDA approval is required and that:
The sponsors of investigations, investigators, or any persons acting for or on behalf of a sponsor or an investigator may not promote or test market an investigational device or represent that it is safe or effective for the purpose for which it is being investigated.
Smith replied that the vacuum fixation device does have an IDE and should not be considered a Class III device, that an Institutional Review Board (IRB) had determined that the device did not pose an unreasonable risk to patients, and that his company plans to submit an application to broaden the way the device is used [16]. However, an FDA official responded that the device had not been formally classified, that new devices are automatically placed in Class III, and that the agency disagreed with the IRB's conclusion [17]. In August 1998, the company submitted an IDE application [7], which the FDA rejected.
Disciplinary Action
In March 1999, Dr. Bores announced that he had retired from clinical practice but would continue to direct research at the American Eye Institute, with which AGI had merged [18]. In December 1999, after additional communication with the FDA, Ophthalmic International was given permission to conduct a small "feasibility study." [19] Federal regulations state that during clinical studies, no investigator or sponsor can commercially distribute an unapproved device, charge subjects more than the amount needed to cover costs, or represent that the device is safe or effective for its intended purpose. According to information from the Arizona Medical Board, Bores did all of these things, lacked FDA approval to conduct any PNT studies, and improperly collected Medicare payments for patients treated between December 1997 and February 1999. In April 2003, the board reprimanded Bores and placed him on two years' probation under which he is barred from conducting studies that do not meet FDA criteria and must reimburse Medicare for $15,539.81 that he had been paid for the 1997-1999 treatments [19].
The Bottom Line
Pneumatic trabeculoplasty has not been proven safe or effective for treating glaucoma; and Coronado Industries' vacuum fixation device lacks FDA approval for such use. It remains to be seen whether additional research will demonstrate benefit.