From extremely distant stars in the universe…
Adaptive optics (AO) technology was born from the desire to get a better view of the universe. Its principles were invented by astrophysicists in order to improve image quality in large ground-based telescopes. AO has revolutionized astronomy by enabling the visualization of extremely distant stars, up to the center of our galaxy.
…to extremely small detail in the eye
Imagine Eyes® has taken AO out of astrophysics labs to provide deeper insight in human eyes. Our team has created an AO technology that improves the assessment of sight defects as well as the quality of retinal images. With our medical AO instruments, clinicians can examine incredibly small detail in patients’ eyes.
A short history of AO technology
Heat and atmospheric turbulence cause distortions in the light received from stars. What we perceive as the twinkling of stars has the consequence of severely blurring the images obtained by terrestrial telescopes, to such an extent that many stars cannot be seen. AO technology has overcome this problem.
Before AO was invented, the only way to get rid of the blurring effect of the atmosphere was to send costly orbital telescopes into space, such as the Hubble Space Telescope. The idea of measuring the distortions of light and compensating for them in real time using deformable optical elements was first proposed in the 1950’s by the astronomer Horace Babcock, but it wasn’t until the 1990’s that technology had matured enough to bring this idea into practice.
In the early 1990’s, major achievements in AO were declassified by the military for use in astronomy. Since then the technology has then been implemented in several major observatories. In the same decade, researchers also began to explore the potential of AO in vision science and ophthalmology.
How it works
When light propagate through a optically imperfect media, the shape of light waves is affected by distortions that make images blurry. AO is a technique that eliminates distortions from light waves. Most AO systems are based on three key components that together operate in a closed-loop feedback configuration:
1. A wavefront sensor that repetitively measures shape distortions in light waves;
2. A deformable mirror that constantly reshapes its reflecting surface in order to compensate for the light’s distortions;
3. Computer algorithms that process the information from the sensor and drive the deformable mirror.
Additionally most astronomical AO systems use an artificial « guide » star to produce the light needed for the wavefront sensor. They do so because sufficiently bright natural stars are not available in every part of the sky. Such a guide star is created by shining a laser beam into the atmosphere.
Adaptive optics, Adapted to eyes
Optically speaking, our eyes are far from being perfect. Optical irregularities in the cornea, lens and intraocular fluids distort light waves, in the same way as the Earth’s atmosphere does. In addition to sometimes impairing vision, these defects always limit the resolution of retinal examinations. The main consequence is that microscopic alterations in the retina, despite their very high medical relevance, have always been invisible to doctors. Imagine Eyes’ AO technology has overcome this limitation and enabled examining patients’ eyes with an unprecedented precision.
Although in theory both astronomy and medicine can benefit from using the same AO principles , in practice the technologies developed for large terrestrial telescopes have fallen far short of meeting the performance, compactness and cost effectiveness needed for medical applications. Imagine Eyes has tackled this challenge and designed a unique core technology that meets all the specifications required for operating with eyes.
More about Imagine Eyes' core technology
Imagine Eyes has miniaturized adaptive optics while making it far less expensive, totally non-invasive, and compatible with the wide range of optical defects that can be found in human eyes. Our team’s effort has also resulted in an intellectual property portfolio that encompasses seven families of patents.
Our medical devices integrate three main technology components:
- Wide-measuring-range Shack-Hartmann wavefront sensor based on precision micro-optics arrays
- Large-stroke deformable mirror powered by patented electromagnetic actuation technology
- Software algorithms that automatically control the adaptive optics system’s operation
Additionally, similar to the « guide star » technique used in astrophysical implementations of AO, Imagine Eyes has created a system that produces a « guide » light source at the retina and thus provides the very specific illumination conditions needed for operating AO in living eyes.