Image sharpening algorithms improve clarity of surgical field during 3D heads-up surgery

Kosuke Nakajima; Makoto Inoue; Aya Takahashi; Yuji Yoshikawa; Masaharu Mizuno; Takashi Koto; Tomoka Ishida; Tetsuro Oshika

doi:10.1186/s40942-023-00462-z

Image sharpening algorithms improve clarity of surgical field during 3D heads-up surgery

Int J Retina Vitreous. 2023 Mar 30;9(1):21. doi: 10.1186/s40942-023-00462-z.

Authors

Kosuke Nakajima¹, Makoto Inoue², Aya Takahashi¹, Yuji Yoshikawa^{1

3}, Masaharu Mizuno¹, Takashi Koto¹, Tomoka Ishida¹, Tetsuro Oshika⁴

Affiliations

¹ Kyorin Eye Center, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 186-8611, Japan.
² Kyorin Eye Center, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 186-8611, Japan. inoue@eye-center.org.
³ Department of Ophthalmology, Faculty of Medicine, Saitama Medical University, 38, Morohongo, Moroyama, Iruma, 350-0495, Saitama, Japan.
⁴ Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, 305-8575, Japan.

Abstract

Background: Image-sharpening algorithms with color adjustments enable real-time processing of the surgical field with a delay of 4 msec for heads-up surgery using digital three-dimensional displays. The aim of this study was to investigate the usefulness of the algorithms with the Artevo 800^® digital microscope.

Methods: Seven vitreoretinal surgeons evaluated the effects of image-sharpening processing on the clarity of the surgical field with the Artevo 800^® system that is used for cataract and vitreous surgeries. The scorings were made on a 10-point scale for anterior capsulotomy, phacoemulsification, cortex aspiration, core vitrectomy, and peeling of an epiretinal membrane or an internal limiting membrane. In addition, the images during the internal limiting membrane peeling were processed with or without color adjustments. We also evaluated the skewness (asymmetry in the distribution of the pixels) and kurtosis (sharpness in the distribution of the pixel) of the images to evaluate the contrast with each intensity of image-sharpening.

Results: Our results showed that the mean visibility score increased significantly from 4.9 ± 0.5 at 0% (original image) to 6.6 ± 0.5 at 25% intensity of the image-sharpening algorithm (P < 0.01). The visibility scores of the internal limiting membrane increased significantly from 0% (6.8 ± 0.3, no color adjustments) to 50% after the color adjustments (7.4 ± 0.4, P = 0.012). The mean skewness decreased significantly from 0.83 ± 2.02 at 0% (original source) to 0.55 ± 1.36 at 25% intensity of the image-sharpening algorithm (P = 0.01). The mean kurtosis decreased significantly from 0.93 ± 2.14 at 0% (original image) to 0.60 ± 1.44 at 25% intensity of the image-sharpening algorithm (P = 0.02).

Conclusions: We conclude that the image-sharpening algorithms can improve the clarity of the surgical field during 3D heads-up surgery by decreasing the skewness and kurtosis.

Trial registration: This was a prospective clinical study performed at a single academic institution, and the procedures used were approved by the Institutional Review Committee of the Kyorin University School of Medicine (reference number, 1904). The procedures also conformed to the tenets of the Declaration of Helsinki.

Keywords: Cataract surgery; Heads-up surgery; Image sharpening algorithm; Three-dimensional surgery; Vitrectomy.