Ophthalmology

WAVEFRONT PHASE


One of the I+D+i lines of Wooptix focuses on the transfer to the ophthalmic clinical community of our technology for the diagnosis, understanding and evaluation of eye diseases and their treatments.

TECHNOLOGY AND HEALTH INNOVATION IN OPHTHALMOLOGY.

Ophthalmology is one of the most technologically advanced areas of medicine. It is a paradigm of science where technological advances have direct and rapid application. One of the lines of R&D at Wooptix is focused in the transfer to the clinical ophthalmic community of improved technology for the diagnosis, understanding and evaluation of eye diseases and their treatments.

Among the list of diagnostic methods in ophthalmology, a relatively new method is the study of the optical imperfections of the eye, called aberrations, that can deteriorate the perceived image. Numerous scientific studies have shown that the visual results after surgical procedures or pathologies are highly influenced by aberrations (e.g. refractive surgery, corneal transplantation, cataract surgery). For this reason and to improve the results, in the last years several instruments are based in the measurement, correction or even induction of aberrations in the eye. Another utility of the measurement and correction of aberrations is for the observation of the interior of the eye, as correcting the pre-existing aberrations of the ocular optics drastically improves the diagnostic images. Also, problems of basic interest in biology such as ocular aging or the development of refractive errors of the eye begin to consider a possible involvement of the ocular aberrations.

Wooptix offers unprecedented resolution in the measurement of ocular aberrations, surpassing by several orders of magnitude the resolutions that can be obtained with other existing methods. In addition, the dynamic range is considerably higher than the one that can be obtained with other systems. And all this is done in real time. These aberrations may be those corresponding to the whole eye or to the first optical surface of the eye, the cornea. Through simple mathematical operations, aberrations of the cornea can be translated to surfaces, allowing the most accurate corneal topographer.

All this is achieved thanks to a new methodology, developed by Wooptix, to measure the light field of a scene. This means that we are able to capture the direction of the photons involved in the scene with all the resolution of the sensor. The majority of sensors can be adapted to this methodology, by means of a very simple modification and without significantly increasing the cost of the final product.

Numerous tests have been performed to validate the Wooptix sensor. Below are two of them. For technical data do not hesitate to contact us in the contact section.

For the first showed test a custom optical system was designed. It consist of a laser beam that focus on a deformable mirror (reflective surface that can modify its shape in a controlled way) to be later divided into two beams of light by mean of a beam splitter. Finally, the image is received by two sensors. The Wooptix sensor was composed of a traditional and slightly modified camera of 800x800 pixels, while the second sensor consisted of a 1440x1080 pixel Shack-Hartmann sensor with a 32x32 microlens array. The mirror was deformed according to a random pattern characterized by the first 50 Zernike modes. As can be seen in the figure, when comparing with the Shak-Hartmann sensor, the results of Wooptix sensor is reliable, but with a resolution of 640000 points, compared to the 1024 points offered by the Shack-Hartmann.

For the second example, the same system was used but with a very deformed surface. The mirror was deformed following the pattern of a cross and measured again with both sensors. As everyone can see in the image, the difference in dynamic range and resolution between both sensors is very large. The level of detail of the Wooptix sensor is such that the influence of the mirror actuators on the wavefront phase can be evaluated in a single shot and in real time, details that are invisible to the Shack-Hartmman unless the ampliation of the optical system is greatly enlarged. It is very striking that the image of the Shack-Hartmann is very similar to what is found by ophthalmologists when they measure corneal astigmatism.

Never before ocular aberrations and ocular topography have been systematically observed in these conditions and with so much resolution. So there is the possibility that, in addition to an improving in current diagnoses on the ophthalmology world, new diagnostic batteries are developed, same as when the retina was first observed in high resolution thanks to retinal OCT technology.

Other applications