Eyeworld

N anotechnology is coming to ophthalmology. "The development of nano- ophthalmology is under way already, albeit at an early stage," according to a report by Marco A. Zarbin, M.D., Institute of Ophthalmology and Visual Science, New Jersey Medical School, Univer- sity of Medicine and Dentistry of New Jersey, Newark. The report was published online in October 2010 in the Canadian Journal of Ophthalmol- ogy. Nanotechnology involves mate- rials and devices of incredibly small size—less than 100 nm. As a point of comparison, a strand of DNA is 2 nm wide, Dr. Zarbin noted. Drug discovery and delivery will likely be among the first scientific areas influenced by nano-ophthal- mology, Dr. Zarbin said. Biopharma- ceuticals, implantable materials, implantable devices, and diagnostic tools are other areas of early impor- tance in this field. What's coming down the pike According to Dr. Zarbin's report, nanotechnology has diverse oph- thalmic applications. Nanoparticles may play a role in the treatment of conditions associated with oxidative damage, particularly AMD, diabetic retinopathy, and retinitis pigmen- tosa (RP). Vacancy-engineered, mixed-va- lence state cerium oxide (CeO 2 ) nanoparticles—also known as nanoceria particles—can prevent light-induced photoreceptor damage in rodents. This prevention can occur with an injection of the parti- cles even after light damage has been initiated. The critical factor that makes these nanoparticles effective is that their surface area to volume ratio is relatively high, allowing them to not only scavenge for reactive oxy- gen intermediates, but also to regen- erate their activity and, therefore, act catalytically. That's just the beginning Imagine a non-invasive method to continuously monitor IOP. Diurnal fluctuation of IOP is an issue that currently makes accurate testing challenging. Nanotechnology allows for new, innovative monitoring ap- proaches. "One noninvasive approach to IOP monitoring involves the use of a wireless contact lens," Dr. Zarbin re- ported. This development involves a disposable silicone contact lens with a sensor that uses strain gauges to measure changes in corneal curva- ture related to IOP changes. "Powering and communication between the contact lens and the recording unit are done wirelessly with a microprocessor and an an- tenna integrated into the lens," Dr. Zarbin said. The contact lens is also thin enough to allow for extended wear. "The device does not provide a quantitative measurement of IOP, but it provides at least a recording of qualitative changes," Dr. Zarbin re- June 2011 by Matt Young EyeWorld Contributing Editor Coming soon: Nano-ophthalmology CAUTION: Federal law restricts this device to sale by or on the order of a physician. INDICATIONS: AcrySof® IQ Aspheric Natural (SN60WF) Posterior Chamber Intraocular lenses are indicated for the replacement of the human lens to achieve visual correction of aphakia in adult patients following cataract surgery. These lenses are intended for placement in the capsular bag. WARNINGS: Careful preoperative evaluation and sound clinical judgment should be used by the surgeon to decide the risk/benet ratio before implanting a lens in a patient with any of the conditions described in the Directions for Use labeling. Some adverse reactions that have been associated with the implantation of intraocular lenses are: hypopyon, intraocular infection, acute corneal decompensation and secondary surgical intervention. Caution should be used prior to lens encapsulation to avoid lens decentrations or dislocations. PRECAUTIONS: Studies have shown that color vision discrimination is not adversely affected in individuals with the AcrySof® Natural IOL and normal color vision. The effect on vision of the AcrySof® Natural IOL in subjects with hereditary color vision defects and acquired color vision defects secondary to ocular disease (e.g., glaucoma, diabetic retinopathy, chronic uveitis, and other retinal or optic nerve diseases) has not been studied. Do not resterilize; do not store over 45° C; use only sterile irrigating solutions such as BSS® or BSS PLUS® Sterile Intraocular Irrigating Solutions. ATTENTION: Reference the Physician Labeling/Directions for Use for a complete listing of indications, warnings and precautions. The long-term effects of ltering blue light and the clinical efcacy of that ltering on the retina have not been conclusively established. ©2010 Alcon, Inc. NIQ10323JAD-PI 75147 NIQ10323JAD_PI EW.indd 1 5/1/11 4:50 PM

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