Researchers look into new techniques that help locate various ocular diseases

By Rabia Ilyas

Researchers at the University have developed a technique that may change the face of various ocular diseases. The technique, known as computational adaptive optics, allows them to examine individual cells in the back of the eye.

The inspiration for the technology is built on an old-age technique called adaptive optics, which was first used in the field of astronomy.

The reference was made to stars because as light initially enters the atmosphere, it gets distorted and therefore causes the eye to see the twinkle of a star. Adaptive optics corrects these distortions coming in the form of light waves, and serves to generate a clear image.

“In the case of our eye, the imperfections are analogous to the atmosphere and we can correct the optical waves going through the eye to create a sharper image,” said Stephen Boppart, professor of bioengineering.

The new technique uses a computational approach where a laser beam is scanned at the back of the eye and the light that bounces back gives information about the structure back there.

As a result, individual cells are clearly depicted, which aids in diagnosing age-related macular degeneration and various neurological disorders such as multiple sclerosis.

The researchers, led by Boppart, corrected the aberrations in the eye computationally, through a technique known as Optical Coherence Tomography (OCT). The technique has been around for over 25 years but it has limitations, as it cannot look at individual cells in the back of the eye.

As a result of this problem, Boppart, who is also a medical doctor, said, “we use the OCT system but we make sure that the data we collect can be corrected so that we can transform those blurry cells into sharp, well-defined cells in optics.”

Imaging techniques like OCT and hardware adaptive optics have been used commonly in the field of medical imaging but have many constraints and drawbacks.

Hardware adaptive optics, for example, have been implemented in OCT systems for a very long time, but this technique is very complicated and can cost thousands of dollars, which leaves few clinicians even using them.

“Our contribution is to do those same sources of corrections without additional hardware, and we accomplish this by taking advantage of data we already have and use adaptive optics computationally,” said Fredrick South, a graduate student who is also a coauthor for the work.

However, as with all technology, limitations are bound to arise. Even with this computational approach, there are certain requirements that must be met to ensure accuracy.

The problem with collecting data computationally arises when the data is not stable.

“It is difficult to capture a high-resolution image as the eye is always moving. Therefore, we have had to develop ways to acquire data quickly and also simultaneously be able to correct for any motion to get the best image out there,” Boppart said.

“This has been the biggest challenge for us throughout the development of this technique, but this is also the unique aspect of our technique,” he added.

It seems, however, that this technique produces far greater benefits than costs to society.

The research team chose to apply this technique to macular degeneration and multiple sclerosis because of the prevalent rates of these diseases.

“This new technology can be applied to any type of retinol imaging and hundreds of diseases as well,” Boppart said.

South added that diabetic retinopathy, caused by changes in the blood vessels of the retina, is one common disease that can be better understood and treated with Computational Adaptive Optics.

There are still questions in this piece of technology that remain unanswered, though. The variety of aberrations due to different eye shapes leads researchers to question if this new technique will be successful for all eyes.

Researchers hope such questions will be answered in the near future. They are working toward the advancement of this technique by making the system more robust, more user-friendly and enabling it to automatically correct aberrations in the eye no matter where imaging of the eye is done.

“We also want to make it more practical and integrate our technology into a system and develop a new product that withstands the capability,” Boppart said.

Getting this product onto the market might not be too difficult for the research team, as there is already a lot of commercial interest in this piece of technology from many manufacturers.

While the commercial success of this technology is satisfying, both Boppart and South agree that the humanistic aspect of this discovery is what attracts them to medical imaging.

“If we can help improve or even save someone’s vision, and by doing so make a big difference in their peoples’ lives, then that is the most rewarding part of my research,” Boppart said.

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