EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/82503
46 EW CATARACT September 2012 Dropped but not lost by Enette Ngoei EyeWorld Contributing Writer Managing the posterior capsular rupture and dropped nucleus with the IOL scaffold technique T he biggest nightmare for a cataract surgeon is a sink- ing nucleus because of a posterior capsular rupture, said Amar Agarwal, F.R.C.S., Dr. Agarwal's Eye Hospital, Chennai, India. Managing these cases is a challenge. If the surgeon refers the case to a posterior segment surgeon, the patient is going to get upset be- cause he will know there is a serious problem, he said. Dr. Agarwal and colleagues therefore described the IOL scaffold technique that can be used by ante- rior segment surgeons to rescue the situation. The principle is very simple, he said. Dialing continued from page 45 However, this must wind itself through the U.S. FDA, which Mr. Pamplona anticipates will likely take 1 or 2 years. In the end, the workability Worker in India using the CATRA, which can show position, size, shape, and density of a cataract Source: Ethan Solomon cians' ability to look at it and say that it is severe enough," Mr. Pamplona said. "They don't have information to make a very accurate diagnosis—it's qualitative." In that sense, he sees the CATRA as offering more information to the doctor. Although there are other high- end instruments that can transform their readings into the same type of map that is offered by the CATRA, they are expensive. "They cost a lot of money," Mr. Pamplona said. "It would be $25,000 or $50,000 in the U.S., so they're not good for the developing world." He pointed out that as a result, these don't help to solve the problem of avoidable blindness in developing countries. "Ours is much cheaper," he said. "We assume that everyone has a cell phone; the plastic piece that goes on top of this to make it work will cost only $3 or $4." On top of that, this will involve downloading an app, something that Mr. Pamplona anticipates will cost at most $0.99. He pointed out that currently there is nothing readily offering this information on maps. It also offers other advantages. "There's the alter- native of checking the progression of the cataract over time because the end users can do this at home, and they can see if it's growing or not— if it's becoming more dense or not," Mr. Pamplona said. In particular, this technology lends itself to undeveloped countries where they don't have ready access to ophthalmologists. "[There are] people in the big cities buying this device and going to villages to screen people," Mr. Pamplona said. "Then they go back to the city and file the data into some hospital, and the hospital decides to bring that person to the city to have the surgery done." This can all be done without having to invest a lot of money, he pointed out. Patients could download the app and if they detected a problem, they could visit a practitioner for treatment, he believes. In the hands of doctors, it could offer more quantitative data. Child in Kenya benefiting from use of the CATRA Source: Edward Wong comes down to the idea that the cell phone has the electronic goods to deliver a reliable diagnosis. "The center for the Hartmann works in the resolution of 10 micrometers, and the cell phone screen has a resolution of 30 micrometers," Mr. Pamplona said. "So you will have in your pocket a device that has only one-third the resolution of a high- end device." Going forward, it is important to start thinking about what else this can be used for, he said. "We have a bunch of other projects in line that can measure, for instance, macular degeneration, dry eyes, and ambly- opia—a lot of different diseases that can start giving people a number," Mr. Pamplona said. "Doctors need to say what this number is, and if it goes beyond that, [patients] need to search for an optometrist or an ophthalmologist." EW Editors' note: Mr. Pamplona has no financial interests related to this article. Contact information Pamplona: vitorpamplona@gmail.com With a sinking nucleus, the first step is to bring the nucleus up ante- riorly with a rod. The posterior assisted levitation technique (PAL), described by Charles Kelman, M.D., can be used, Dr. Agarwal said. After that, the next obstacle is removing the nucleus from the eye. "If I now emulsify it with a phaco machine, some pieces will fall as there is no capsule. The second choice is to open my incision and make it a large incision of 6-8 mm; that means if I'm clear corneal, I have to cut the sclera, I have to put sutures in, then I have to put the lens in, which is another challenge. So in other words, my small incision has become a large incision," he said. A third alternative would be to use a glide that expands, place it right under the nucleus, and then emulsify the nucleus, but again, the incision would have to be extended, he said. This is where the IOL scaffold technique comes in. As described by Dr. Agarwal and colleagues, an anterior chamber maintainer is introduced through a 1.2 mm stab micro-vitreoretinal blade incision. The position of the AC maintainer should be away from the PCR and flow should be kept low. Anterior vitrectomy is done with the vitrec- tomy cutter to remove the vitreous prolapsed in the anterior chamber. An Agarwal globe stabilization rod (Katena, Denville, N.J.) passed through the sideport helps to push the fragment away from the PCR. The fragments are brought into the anterior chamber. A foldable IOL is then injected via the existing corneal wound and is maneuvered below the nucleus. The leading hap- tic of the IOL is positioned above the iris, and the trailing haptic is placed just outside the incision site. Using a dialer in the non-dominant hand, the junction of the optic hap- tic junction on the trailing side is maneuvered so that the IOL blocks the pupil. Thus the IOL acts as a scaffold and prevents the fragments from falling into the vitreous cavity. The nucleus fragment is then removed with the phaco probe (low flow and vacuum). Cortex is re- moved with suction and low aspira- tion using a vitrectomy probe. The non-dominant hand adjusts the trailing optic haptic junction so that the IOL is well centered over the pupil acting as a scaffold while emulsifying the nucleus. Once cortical cleaning is done, the IOL is placed over the capsular remnants in the ciliary sulcus. The AC main- continued on page 47