Indian-led MIT team develops cheap device to detect cataracts

Updated on: Wednesday, July 06, 2011

A team of researchers at MIT, led by India-born professor Ramesh Raskar, has developed a simple and cheap device that can be clipped onto an ordinary smart phone or an iPod and can diagnose the cataracts within a few minutes.

Dubbed 'Catra', the cost-effective device works as a radar for the human eye, the NEC Career Development Associate Professor of Computer and Communications and director of the Media Labs Camera Culture group at Massachusetts Institute of Technology, Ramesh Raskar said.

"Just as a weather radar beam sweeps across the sky to detect clouds, Catra sweeps a beam of light across the eye to detect the cloudy patches called cataracts," Raskar explained.

The device can also clip onto a smart device such as an iPod.

Cataracts are the leading cause of preventable blindness worldwide.

The standard test to detect the cloudy patches in the eye's lens requires a USD 5,000 piece of equipment called a slit lamp, and a trained physician to interpret its results - two things that are often not available in rural and less- affluent parts of the world.

Media Lab graduate student Vitor Pamplona, a member of the team developing Catra, explains that the device "scans the lens of the eye and creates a map showing position, size, shape and density of cataracts."

"Catra could provide great value as a simple and low-cost way of making the initial diagnosis that cataracts are present, especially in parts of the developing world where such services are now rare and often require travel to distant cities," an MIT statement said.

In addition, the new device may be able to detect cataracts at an earlier stage than existing tests, because it can pick up changes in parts of the lens that have not yet become opaque.

Currently, tests depend on light reflected back by the lens, to be seen by the doctor performing the test, while Catra relies on light passing through the lens as reported by the patient, who just has to indicate whether a point of light remains steady, dims or disappears.

"We turned the problem around, instead of asking the doctor, we ask the patient, Raskar said..

The new screening tool will be presented at the annual computer-graphics conference SIGGRAPH to be held in August in Vancouver.

The new work is a follow-up to the teams earlier development of a system called NETRA that uses a smart phone with a different clip-on attachment to measure refractive errors of the eye.

"Together, NETRA and Catra may become extremely valuable tools for screening patients that need eye-care assistance, especially in regions where eye doctors are not readily available," says Manuel Oliveira, a visiting professor from Brazil's Universidade Federal do Rio Grande do Sul and a member of the team.

There are 250 million people in the world who are blind because of preventable causes.

An inexpensive, portable device such as Catra, Raskar says, might help make a serious dent in that number.

Indian-led MIT team develops cheap device to detect cataracts

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