New Glaucoma Treatment Gives Patients Options Beyond Costly Medications or Surgery

FOR IMMEDIATE RELEASE

Brookville, PA (May 26, 2010) – [Dr. Louis “Skip” Nichamin of The Laurel Eye Clinic in Brookville, Pennsylvania, is one of the early practitioners in the United States performing Canaloplasty, an exciting new treatment that utilizes a microcatheter to give ophthalmologists and their patients hope of managing glaucoma without traditional surgery or medications. And a recent international, multicenter clinical study has demonstrated Canaloplasty’s effectiveness in treating glaucoma by reducing intraocular pressure (IOP).

According to Dr. Nichamin, “For decades, eye surgeons have recognized that the ideal solution to glaucoma would revitalize the eye’s aqueous outflow and maintain healthy tissue. Thanks to the development of microcatheters and imaging technology small enough to work in the eye, Canaloplasty is showing potential to revolutionize the way we treat glaucoma.”

Glaucoma is a progressive disease of the eye for which there is no cure. The disease is caused when the natural fluid channels in the eye become blocked or clogged. These clogged channels result in increased intraocular pressure which causes permanent damage to the optic nerve. The optic nerve is essential for vision because it is the primary mode of transmitting images and vision information from the eye to the brain. Glaucoma affects an estimated 3 million people in the United States and 65 million people worldwide. About 120,000 Americans are blind due to glaucoma according to the Glaucoma Research Foundation.

Medications have traditionally been the first line of defense against the further progression of glaucoma once it has been diagnosed. Glaucoma medications, which must be taken daily, are very expensive and are not always effective. Studies show that the cost of glaucoma medications per patient has increased by as much as 148% since 1997. In certain cases where medications have proven ineffective, glaucoma surgery can be performed; however, the results are inconsistent and can cause considerable trauma to the eye.

Canaloplasty revitalizes the eye’s fluid outflow system to help manage IOP. It is a straightforward, nonpenetrating outpatient procedure that takes about 30–45 minutes, and is significantly less traumatic to the eye than more invasive traditional surgical treatments. In Canaloplasty, a tiny microcatheter is fed through a small incision to enlarge Schlemm’s canal, a natural drainage pipeline in the eye.

According to the study published in the July 2007 edition of the Journal of Cataract and Refractive Surgery, Canaloplasty is effective and safe in treating glaucoma by lowering intraocular pressure (IOP) in adults with angle closure glaucoma. Patients in the study experienced a 38% reduction in IOP which causes optic nerve damage and vision loss. In addition, the need for costly drugs developed to help lower IOP was reduced by up to 68% and about one-half of patients required no further medication.1

For more information about glaucoma and Canaloplasty, visit www.laureleye.com or www.Canaloplasty.com.

Reference:
1. Lewis RA, von Wolff K, Tetz M, et al. Canaloplasty: circumferential viscodilation and tensioning of Schlemm’s canal using a flexible microcatheter for the treatment or open-angle glaucoma in adults. Interim clinical study analysis. J Cataract Refract. Surg. 2007;33(7):1217-1226.
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Femtosecond Laser Technology Applied to Lens-Based Surgery

Femtosecond Laser Technology Applied to Lens-Based Surgery
Louis D. “Skip” Nichamin, M.D.

Introduction
Arguably the last global Milestone within the field of cataract surgery was the introduction of phacoemulsification by Kelman[1]. Through his pioneering work phacoemulsification became a reality as a means by which surgeons could break up the cataractous lens and remove it through a small incision. Over the ensuing 40 years this led to further refinements in surgical technology and technique, yielding additional reduction in incision size, sutureless wound closure, the development of ophthalmic viscoelastic agents, and intraocular lenses that now achieve unprecedented levels of visual function. The introduction of phaco affected every aspect of cataract surgery and led to the present day standard of care.

Laser Cataract Surgery
Recently, an emerging new technology appears to represent a similar paradigm shift in the world of refractive cataract surgery: the introduction of ultra-short pulse (femtosecond) lasers. Since their introduction, there has been a move towards the development and use of such lasers in order to make precise cuts that can enhance the safety and efficacy of ophthalmic surgery[2]. It is well accepted that short pulse lasers have advanced corneal flap creation for keratorefractive surgery, in part, by greatly increasing the predictability and consistency of the corneal cut compared to that of a manual microkeratome blade cut [3]. However, the newest innovation in anterior segment surgery is the use of ultra-short pulse lasers in cataract surgery. Instead of a manually torn capsulorhexis the laser can create a precise, laser- cut anterior capsulotomy which is well centered, of exact size and of perfect shape. Using the laser to fragment the lens prior to aspiration and making the necessary corneal incisions can create a laser-based cataract surgery that should reflect the precision and accuracy normally associated with other all laser-based procedures. The new LensAR Laser System™ introduces the possibility of entering the operating room with the knowledge that the cataract patient will have the exact capsulotomy, clear corneal incision and astigmatic corneal relaxing incisions that are desired along with a laser-treated cataract that requires little or no ultrasonic energy to remove.

Anterior Capsulotomy
Studies have shown the benefits of the laser-based procedures. Nichamin [4] reported on an assessment of anterior capsulotomy when compared to manual capsulorhexis. It was found that the laser capsulotomy was not only significantly closer to the intended diameter by a factor of almost three, but the shape was also significantly rounder than the manually torn rhexis.

Lens Fragmentation
More recently, data has been presented that shows the benefits of fragmenting the lens with the laser prior to lens extraction thereby reducing the amount of ultrasound energy used during the surgery. Fishkind[5] presented results that showed phaco energy (expressed as Cumulative Dissipated Energy or CDE) in a group with the lens fragmented with the LensAR Laser System was reduced compared to a control group which underwent conventional phacoemulsification. Reductions in CDE ranged from 40% for LOCS III Grade 4+ cataracts to 95% for LOCS III Grade 2 cataracts. In particular, the ability to fragment and remove higher grade (Grades 3 & 4) cataract has surgeons particularly excited, especially since LensAR is the only company to have presented such data. Since invasive surgery is associated with a breakdown in the blood-aqueous-barrier (BAB) and Pande[6] has suggested that less invasive procedures result in less BAB disruption, it might be expected that laser lens fragmentation could result in less anterior chamber reaction than conventional phacoemulsification if the ultrasound energy is reduced. Early clinical results from a clinical study with the LensAR Laser System [7] suggest that this might be the case. Earlier visual rehabilitation with ultra-short pulse lasers may also be expected and has been seen in early data with the LensAR Laser System[7].

Clear Corneal Incisions
As noted, the precision of the laser has been well documented in making lamellar incisions in the fields of keratorefractive and corneal transplant. Their application to cataract-related corneal incisions is a logical extension to this indication. While clear corneal incisions offer significant surgical advantages there has been a purported increase in the incidence of endophthalmitis with their use.[8, 9]. The potential for sutureless wounds to leak after the completion of surgery is linked directly to the architecture of the incision, the complexity of the case (with the resulting increased manipulation through the wound) and the care with which the wound is hydrated at the end of the case. While a skilled surgeon can manually create the required wound architecture, other factors such as placement of incision, blade type and patient factors such as deep set eyes, etc . may impact the repeatability of the procedure. The laser can produce a consistent incision of the required dimensions regardless of placement or patient features. More importantly, the characteristics of the incision, including size and length, can be adjusted to suit individual cases. A tongue-and-groove design may further help to ensure a total seal at the end of surgery.

Limbal Relaxing Incisions
As the premium lens share of the cataract market increases, so the need for exceptional postoperative uncorrected visual acuity increases with it. Corneal astigmatism can limit the quality of post-operative vision and presbyopic-correcting lenses often require this astigmatism to be minimized if optimum results are to be obtained. Since toric lens options are not common for presbyopic lenses, limbal relaxing incisions remain an integral part of the refractive cataract procedure. They have been shown to be a relatively simple, safe and effective way to correct astigmatism, [10, 11] but the need for individual nomograms [12] suggests that there is some inter-surgeon variability to the technique. The femtosecond laser can create limbal relaxing incisions and has the precision and repeatability necessary for consistent outcomes that cannot easily be achieved with a manual method using a blade. A recent review [13] showed how the effect of laser-induced incisions can be predicted from finite element analysis models and can then be compared to untreated eyes or manually treated eyes to demonstrate effectiveness.

Presbyopia
One final area of research is the correction of presbyopia. The potential for the LensAR Laser System to use photodisruption to create shaped structural weakening within the lens and thus to restore some flexibility, is the subject of ongoing clinical research. Having demonstrated the feasibility of the technique, [14] work has continued in order to demonstrate safety in animal models before human trials could begin [15]. A review of this work [16] earned Dr. Ronald Krueger the best paper in the session award at ASCRS 2010. Laser lens treatment has been shown to reduce the rigidity of the lens and allow it to take up more change in shape than without treatment. Animal studies have shown that there is no progressive cataract as a result of the photodisruption. As a result, human clinical feasibility trials are underway and it is anticipated that results will be published in the near future. This is an exciting application of ultra-short pulse lasers that increases the potential to enhance patient visual performance and LensAR is the only company worldwide to be conducting clinical trials in human subjects.

Summary
The application of femtosecond laser technology to cataract surgery and presbyopia treatment is the latest enhancement of ophthalmic surgery. The increased precision of the technology can help in the improvement of surgical outcomes while assisting exp
erienced and inexperienced surgeons achieve more consistent results.

References
1. Kelman CD (1967) “Phaco-emulsification and aspiration. A new technique of cataract removal. A preliminary report.” Am J Ophthalmol 64(1):23-35
2. Misiuk-Hojlo M, Krzyzanowska P, Hill-Bator A (2006) “Therapeutic application of lasers in ophthalmology” Proceedings of the Symposium on Photonics Technologies for 7th Framework Program, Wroclaw 12-14 October
3. Stonecipher K, Ignacio TS, Stonecipher M (2006) “Advances in refractive surgery: microkeratome and femtosecond laser flap creation in relation to safety, efficacy, predictability, and biomechanical stability” Curr Opin Ophthalmol. 17(4):368-72.
4. Nichamin LD, Naranjo Tackman R, Villar Kuri J, Fishkind W (2009) “Laser capsulotomy with the LensAR Laser System” paper presented at the Annual Meeting of the American Academy of Ophthalmology, San Francisco.
5. Fishkind W, Uy H, Naranjo Tackman R, Villar Kuri J (2010) “Alternative fragmentation patterns in femtosecond laser cataract surgery: paper presented to the Annual Meeting of the American Society of Cataract & Refractive Surgery, Boston.
6. Pande MV, Spalton DJ, Kerr-Muir MG, Marshall J (1996) “ Postoperative inflammatory response to phacoemulsification and extracapsular cataract surgery: aqueous flare and cells” J Cataract Refract Surg. 22 Suppl 1:770-4.
7. Edwards K, Frey R, Naranjo Tackman R, Villar Kuri J, Quezada N, Bunch T (2010) “Clinical outcomes following laser cataract surgery” poster presentation to the Annual Meeting of the Association for Research in Vision and Ophthalmology, FT Lauderdale.
8. Cooper BA, Holekamp NM, Bohigian G, Thompson PA (2003) “Case-control study of endophthalmitis after cataract surgery comparing scleral tunnel and clear corneal wounds” Am J Ophthalmol. 136(2):300-5.
9. Wallin T, Parker J, Jin Y, Kefalopoulos G, Olson RJ (2005) “Cohort study of 27 cases of endophthalmitis at a single institution” J Cataract Refract Surg. 31(4):735-41.
10. Budak K, Friedman NJ, Koch DD (1998) “Limbal relaxing incisions with cataract surgery” J Cataract Refract Surg. 24(4):503-8.
11. Müller-Jensen K, Fischer P, Siepe U. 1999 “Limbal relaxing incisions to correct astigmatism in clear corneal cataract surgery” J Refract Surg. Sep-Oct;15(5):586-9.
12. Nichamin LD (2006) “Nomogram for limbal relaxing incisions” J Cataract Refract Surg. 32(9):1408.
13. Nichamin LD, Teuma V, Bott S (2010) “Use of Femtosecond Lasers to Create Corneal Incisions” paper presented to the Annual Meeting of the American Society of Cataract & Refractive Surgery, Boston.
14. Frey RW, Olmstead RT, DeCastro J, Zepkin N, Thornton I, Yielding RH (2007) “Modification of lens mechanics of human cadaver and porcine lenses using photodisruption laser to change lens power and increase flexibility” Invest Ophthalmol Vis Sci 48 E-abstract 3834.
15. Krueger RR, Yeilding RH, Frey RW (2010) “Femtosecond laser treatment of the crystalline lens for accommodation restoration” poster presentation to the Annual Meeting of the Association for Research in Vision and Ophthalmology Ft Lauderdale.
16. Krueger RR, (2010) “Restoring accommodation using intralenticular laser photodisruption” paper presented to the Annual Meeting of the American Society of Cataract & Refractive Surgery, Boston.