(1) To determine the optimum corneal incision that provides the best sealing abilities with minimum induced astigmatism.
(2) To compare the engineering analysis of the MultiKeratome, a keratome that is curved or arched with multiple points, for a diamond blade with that of a stainless steel blade.
(1) An engineering analysis is performed.
• A curved keratome cuts a curved cornea more evenly while creating
1. a frown incision parallel to the iris plane that is known to minimize the astigmatism, and
2. a thinner internal flap that more readily closes under higher/lower Intra-Ocular Pressures (IOPs).
• Multiple tips placed adjacent to each other creates a wider tunnel on a single pass, while
1. increasing the area of an incision parallel to the iris plane to seal more effectively under lower IOPs, and
2. making a larger internal flap that seals more effectively under both high and low IOPs.
(2) An engineering analysis is performed for the diamond and stainless steel bladed MultiKeratome using a biplanar incision. The diamond-blade MultiKeratome
• Must have a curved or arched surface made of straight-line segments due to manufacturing limitations
• Makes an incision that has
• For the first horizontal incision: A larger area to seal better under lower IOPs.
• For the second inclined incision: A larger and more evenly thin internal flap that closes more readily under higher and lower IOPs.
(1) The engineering analysis results in modifications to both instrument and procedure.
• Combining both curvature and multiple tips more readily
1. enables a biplanar incision that minimizes the induced astigmatism, and
2. makes a complete tunnel thru the entire width of incision to maximize the length bacteria must travel to create endophthalmitis.
(2) Because a diamond blade keratome shaped like a flat-tipped screwdriver or chisel may cut effectively, a diamond blade MultiKeratome makes the areas for the first horizontal and second inclined incisions larger to seal better under both higher and lower IOPs.
(1) A curved keratome with multiple points more readily allows a biplanar incision and is engineered to provide (a) the best sealing capabilities to prevent infections and (b) the minimum induced astigmatism. Due to the increased surface area of the blade, more force is necessary to make these incisions.
(2) A diamond-blade MultiKeratome is engineered to provide better sealing at higher and lower pressures than a stainless steel blade.
The MultiKeratome is already manufactured by USIOL, Inc., in (disposable) stainless steel for the same cost as typical, flat, single-pointed keratomes (~$20ea). Several manufacturers are reviewing their manufacturing processes to produce (reusable) diamond/diamond-like MultiKeratomes (~$2,000ea) that are reasonably expected to make laser-like incisions cost-effective [versus femtosecond lasers (~$500,000ea)].
Marketing will focus on (1) ophthalmologists through publications in professional journals and presentations at conferences, and (2) cataract patients through advertisements in periodicals and on TV. [Note: There are about 3,000-6,000 serious sight threatening infections/year in the US after cataract surgery (based upon a 0.1-0.2% infection rate for endophthalmitis and three million cases).]