Patients receiving comprehensive eye exams have to go from one imaging device to another in order to properly assess their vision. In addition to the hassle, there are costs associated with maintaining and housing multiple pieces of equipment of which only one is usually used at any one time in a typical ophthalmology office.
Now researchers at Nicolaus Copernicus University, Poland and Universidad de Murcia, Spain have developed a device that can provide different views of the eye, and with an image quality even better than using multiple instruments.
Current technology images the eye to about 3 millimeters in depth and changing focus to be able to resolve the front and back of the eye is quite difficult with traditional optics. In order to be able to quickly switch between very different optical properties, the researchers built in an electrically tunable lens into a custom-made optical coherence tomography (OCT) system and used a laser that can rapidly switch between different wavelengths. The electrically tunable optics provide a greater range of possible focus while the swept light source laser gives better resolution and faster scanning.
In addition to being able to focus on both the front and back of the eye, the new OCT device is able to see the how the thin layers where the vitreous gel connects with the retina and lens. This can help identify the reasons why the retina often detaches in elderly people. “We also want to use our instrument to measure opacities in the eye’s crystal lens and the vitreous to better understand how various parts of the eye affect the deterioration of vision,” said Ireneusz Grulkowski of Nicolaus Copernicus University. “We believe that the ability to measure these opacities and other properties of the eye that couldn’t be examined before will open up many new ophthalmology applications for OCT.”
Here you can see the instrument’s optics switching focus:
Here you can see what a quickly changing depth of field looks like: