Abstract
Purpose :
A new generation femtosecond laser is currently in development for corneal lenticule extraction for refractive surgery. Combined with iris registration and corneal mark registration, the new femtosecond laser will be used to perform a wavefront-guided lenticule treatment on a surgical eye. The goal of this paper is to evaluate iris registration on the new femtosecond laser system.
Methods :
33 paired eye images from 33 subjects were collected in a clinical study of the new femtosecond laser. Each paired images included one eye image captured by a diagnostic device (iDesign Wavefront Studio system, Johnson & Johnson Vision, Inc) when the subject was in a seated position, and an image of the same eye captured on the laser system before applanation at 40mm from the patient interface when the subject was in the supine position. The diagnostic eye images were imaged under the infrared illumination of 780 nm and 940 nm wavelength, while the laser eye images were imaged under the infrared illumination of 835 nm wavelength. An image processing software was used to evaluate the image processing quality and iris registration with the 33 paired eye images. The identified matched blocks in the unwrapped iris images from each paired images should be 21 or better for a successful iris registration capture.
Results :
On average, the detected pupil diameter from the 33 diagnostic eye images was 6.444±0.968 mm, (range from 4.176 mm to 8.088 mm), and the iris diameter was 12.383±0.3222 mm (range from 11.784 mm to 13.019 mm). The pupil boundary and outer iris boundary in all 33 laser eye images were detected correctly. On average, the detected pupil diameter from the 33 laser eye images was 5.043±0.981 mm(range from 2.719 mm to 7.130 mm), and the iris diameter 12.144±0.316mm (range from 11.265 mm to 12.648 mm). The average cyclotorsion angle detected in the 33 paired eye images was 0.62 ±2.53° (range from -3.52° to 6.13°), and the matching blocks identified in each paired diagnostic eye image and laser eye image were all above the 21. The capture rate of iris registration between the diagnostic device and the new femtosecond laser system achieved 100%.
Conclusions :
Pupil boundary and outer iris boundary were detected correctly in the 33 eye images from the new femtosecond laser. The infrared eye images captured on the new femtosecond laser are adequate for iris registration with human eyes.
This is a 2021 ARVO Annual Meeting abstract.