A pocket-sized retina camera, no dilating required

March 20, 2017 by Sharon Parmet, University of Illinois at Chicago
Dr. Bailey Shen, a resident in the department of ophthalmology and visual sciences in the UIC College of Medicine, has his retina photographed using a camera based in the Raspberry Pi 2 computer. Credit: Bailey Shen.

It's the part of the eye exam everyone hates: the pupil-dilating eye drops. The drops work by opening the pupil and preventing the iris from constricting in response to light and are often used for routine examination and photography of the back of the eye. The drops sting, can take up to 30 minutes to work, and cause blurry vision for several hours afterwards, often making them inconvenient for both patient and doctor.

Now, researchers at the University of Illinois at Chicago College of Medicine and Massachusetts Eye and Ear/Harvard Medical School have developed a cheap, portable that can photograph the without the need for pupil-dilating eye drops. Made out of simple parts mostly available online, the camera's total cost is about $185.

"As residents seeing patients in the hospital, there are often times when we are not allowed to dilate patients—neurosurgery patients for example," said Dr. Bailey Shen, a second-year ophthalmology resident at the UIC College of Medicine. "Also, there are times when we find something abnormal in the back of the eye, but it is not practical to wheel the patient all the way over to the outpatient eye clinic just for a photograph."

The can be carried in your pocket, Shen said, and can take pictures of the back of the eye without eye drops. The pictures can be shared with other doctors, or attached to the patient's medical record.

The camera is based on the Raspberry Pi 2 computer, a low-cost, single-board computer designed to teach children how to build and program computers. The board hooks up to a small, cheap infrared camera, and a dual infrared- and -emitting diode. A handful of other components - a lens, a small display screen and several cables - make up the rest of the camera.

The camera works by first emitting , which the iris - the muscle that controls the opening of the pupil - does not react to. Most retina cameras use white light, which is why pupil-dilating eye drops are needed.

The infrared light is used to focus the camera on the retina, which can take a few seconds. Once focused, a quick flash of white light is delivered as the picture is taken. Cameras exist that use this same infrared/white technique, but they are bulky and often cost thousands of dollars.

Shen's camera photos show the retina and its blood supply as well as the portion of the optic nerve that leads into the retina. It can reveal health issues that include diabetes, glaucoma and elevated pressure around the brain.

Shen and his co-author, Dr. Shizuo Mukai, associate professor of ophthalmology at Harvard Medical School and a retina surgeon at Massachusetts Eye and Ear, describe their camera and provide a shopping list of parts, instructions for assembly, and the code needed to program the camera in the Journal of Ophthalmology.

"This is an open-source device that is cheap and easy to build," said Mukai. "We expect that others who build our camera will add their own improvements and innovations."

"The device is currently just a prototype, but it shows that it is possible to build a cheap camera capable of taking quality pictures of the retina without dilating eye drops, " Shen said. "It would be cool someday if this device or something similar was carried around in the white-coat pockets of every ophthalmology resident and used by physicians outside of ophthalmology as well."

Explore further: New glasses project images directly onto retina with a mini-laser

Related Stories

New glasses project images directly onto retina with a mini-laser

March 2, 2016
A Japanese company called QD Laser in collaboration with the University of Tokyo has developed a pair of glasses that come with a tiny camera that captures data and a laser that prints imagery from the camera directly onto ...

Researchers use smart phone photography to diagnose eye disease

September 24, 2013
Retinal (or fundus) photography is an essential part of any ophthalmology practice. Commercial fundus cameras can cost tens to hundreds of thousands of dollars, making the technology out of reach for smaller ophthalmic practices ...

Light introduces multi-aperture computational camera

October 9, 2015
Hold it right there. Say cheese or, more appropriately, wow. The L16 is a small camera that enables professional-quality photos.

Detecting eye diseases using smartphone technology

July 6, 2015
Researchers at the Medical and Surgical Center for Retina have developed software that detects eye diseases such as diabetic macular edema using a smartphone. The system is aimed at general physicians who could detect the ...

Recommended for you

In effort to treat rare blinding disease, researchers turn stem cells into blood vessels

February 13, 2018
People who inherit a mutated version of the ATF6 gene are born with a malformed or missing fovea, the eye region responsible for sharp, detailed vision. From birth, their vision is severely limited, and there is no cure. ...

Antioxidant therapy prevents devastating vision loss when added to standard-of-care on rare birth defect

February 5, 2018
A new study led by vision researchers at the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo and VA Western New York Healthcare System has demonstrated that the addition of widely available ...

Genetic basis for glaucoma uncovered

January 30, 2018
In two recent publications, Northwestern Medicine scientists and international collaborators discovered mutations that cause improper drainage and a buildup of ocular pressure leading to one form of congenital glaucoma, and ...

Study advances gene therapy for glaucoma

January 16, 2018
While testing genes to treat glaucoma by reducing pressure inside the eye, University of Wisconsin-Madison scientists stumbled onto a problem: They had trouble getting efficient gene delivery to the cells that act like drains ...

New study offers added hope for patients awaiting corneal transplants

January 9, 2018
New national research led by Jonathan Lass of Case Western Reserve University School of Medicine has found that corneal donor tissue can be safely stored for 11 days before transplantation surgery to correct eye problems ...

Diabetic blindness caused and reversed "trapped" immune cells in rodent retinas

January 3, 2018
Johns Hopkins researchers have discovered a cell signaling pathway in mice that triggers vision loss in patients with diabetic retinopathy and retinal vein occlusion – diseases characterized by the closure of blood vessels ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.