NovOculi's technology is an improvement on the common laser refractive surgery procedure LASIK. In order to fully explain NovOculi's technology, it is first necessary to develop an understanding of its predecessors in the laser refractive surgery industry. After this has been accomplished, NovOculi's technology will be described, competing technologies will be analyzed, sourcing issues will be addressed and, finally, future products will be discussed.
Refractive correction, in all forms, is accomplished through alteration of the contours of the cornea. This alteration is accomplished by destroying either the stroma (middle layer of the cornea) or the epithelium (outer, protective layer of the cornea) of the cornea, and in some cases, both.
Early procedures, such as PRK, used lasers to change the contour of the cornea by destroying both the epithelium and the stroma through simply blasting the cornea straight on without any preparation. This procedure was difficult for patients as the healing took weeks and the destruction of the epithelium left the eye permanently susceptible to infections and ulcers.
LASIK was an improvement over PRK due to the fact that most of the protective layer of epithelium was folded back, and only the stroma of the cornea was destroyed. In order to fold the epithelium back, though, a large, circular incision in the cornea was necessary. While LASIK was an advance in technology in that the epithelium was not destroyed, the incision itself was found to cause multiple problems such as night blindness, loss of sight, permanent sensation of irritation, etc.
3.1 Product Description
In an effort to avoid the complications associated with corneal incision and epithelial destruction utilized in laser refractive surgery procedures, NovOculi's principals designed NICS (Non-Invasive Corneal Sculpting). NICS allows for effective laser refractive correction without the troublesome corneal incision. The subject matter of NovOculi's technology is currently protected by Provisional Patent No. 60/243,031.
NovOculi's technology involves using an ionically charged, contact lens-shaped plate to drive an ionically charged dye into the cornea without making an incision. This use of a charge to attract or repel another charge is termed iontophoresis, and since the charge on NovOculi's plate can be reversed, to either attract or repel the dye, this component of NICS is referred to as the reversible polarity iontophoretic device (RPID). By exposing a charged dye to the RPID which has been set to the same polarity, the dye will effectively be driven through the relatively resistant corneal epithelium and stroma via the repulsion of similar charges. Without this electrostatic repulsion, it would take hours to allow the cornea to soak up the dye, making the procedure difficult, if not impossible.
The ionic dye used in NICS is tartrazine, a common food coloring additive. Tartrazine is a small, stable, yellow dye which absorbs visible light at 440 nanometer (nm) and is positively charged. In order to make sure that the tartrazine is delivered only to the cornea, NovOculi has developed a unique contact lens impregnated with tartrazine which incorporates a barrier to lateral diffusion. This barrier prevents the remainder of the eye from being exposed to the tartrazine and allows for more precise dye delivery.
By controlling the duration of the iontophoresis, during which the RPID will be positively charged to repel the tartrazine, the dye is selectively placed in the middle of the cornea, away from the sensitive epithelial and endothelial layers. Once this has been accomplished, the middle layer of the cornea can be selectively targeted by a 440 nm wavelength laser without ever having to destroy any portion of the protective epithelium.
After the cornea has been sculpted with the laser, the RPID is then reapplied with reversed polarity and the dye is extracted from the cornea, leaving a clear, sculpted cornea.
In summary, NICS is performed as follows:
- Drops are applied to the epithelium of the cornea to decrease sensation and increase dye permeability.
- A contact lens of varying polymeric density and charged with ionic dye, tartrazine, is placed on the epithelium of the cornea of the eye to be corrected, then the RPID (charge-inducing plate) in the shape of a contact lens is placed over the dye.
- The RPID is activated with a charge similar to the dye, thereby forcing the dye into the eye.
- The cornea is washed free of the dye and the iontophoretic plate is reapplied to drive the dye beyond the epithelial layer of the cornea, but above the endothelial layer.
- Once the dye is selectively located in the stromal layer of the cornea, a laser tuned to the wavelength of the dye, 440 nm, is used to sculpt the cornea using the standard laser refractive surgery protocol.
- The reversible iontophoretic device is then reapplied with its charge reversed in order to draw the dye out of the cornea due to their now opposite charges attracting.
- The eye heals and the stroma resorbs over the course of one to two weeks during which sight improves to 20/20 (or better!).
NovOculi's novel technology is found in 1) The overall method of selectively ablating stromal corneal cells, 2) The Reversible Polarity Iontophoretic Device, and 3) The dye-impregnated polymeric contact lens, all of which are currently intellectual property of Daniel R. Burnett, one of the principals.
While NovOculi's technology is novel, the principles on which it is founded are well established. The targeted destruction of certain cells through delivery, then stimulation, of a photoactive substance has been accomplished elsewhere in the human body in the treatment of cancer and has been termed Photodynamic Therapy ("Targeted intracellular delivery of photosensitizers to enhance photodynamic efficiency," Immunology & Cell Biology, August 2000). Also, the delivery of ionic substances into the eye has been successfully accomplished in studies attempting to increase the ocular delivery of dilating drops and antibiotics ("The role of iontophoresis in ocular drug delivery," Journal of Ocular Pharmacology, Spring 1994). Thus, the principles on which NovOculi's technology rests have been proven in related studies, yet never applied in the laser refractive surgery until now, with the development of NovOculi's patented method and devices.
Most of the components involved in NovOculi's method of corneal sculpting are relatively inexpensive and common. The iontophoretic plate, for example, is constructed of standard electronic components and its power source can be either an outlet or a common battery. Tartrazine, the ionic dye, is the most common food coloring additive used in the United States, making this component ubiquitous.
The one component which will be more expensive and difficult to obtain will be the refractive laser tuned to the wavelength of the ionic dye. Partnership with a laser manufacturer would be beneficial in facilitating the development of this laser and well-received efforts have been made to form this relationship.
3.3 Future Products
Future products of NovOculi, Inc. will be medical devices in the field of ophthalmology. Two of the principals, Dr. Daniel Burnett and Dr. Terry Kim, as well as one of the consultants, Dr. Mark Blumenkranz, are intimately involved in the field of ophthalmology and have experience in the R&D of biomedical devices.
In order to capitalize on NovOculi's core competency in ophthalmic devices, the company will focus its efforts in this arena. One example of a device currently in the R&D pipeline is a contact lens formed from a calcium alginate polymer impregnated with one of a variety of ophthalmically active drugs. Use of this slow-release, once-a-day therapy will allow many patients to be treated much more effectively and more conveniently than the current therapy which requires repetitive application of eye drops, sometimes as often as once an hour.