Color enhancement and achromatization to increase the visibility of indocyanine green-stained internal limiting membrane during digitally assisted vitreoretinal surgery.

Purpose: To investigate the impact of using digital assisted vitrectomy (DAV) for color enhancement in color channel and achromatization in color profile on the visibility of indocyanine green (ICG)-stained internal limiting membrane (ILM).

Study design: Retrospective observational study.

Methods: Twenty eyes from 20 patients (7 men, 13 women) who underwent 27-gauge pars plana vitrectomy for epiretinal membrane removal were included. The presettings of five different imaging modes of the NGENUITY^® 3D visualization system (Alcon laboratories, Inc.), were adjusted, and intraoperative images of ILM removal were captured under each presetting. The color contrast ratios (CCR) between the ICG-stained ILM area and peeled ILM area were compared across presettings objectively. Subjective visibility of ILM in each patient for different presettings was ranked using a Likert scale and evaluated by five examiners. Data on sex, age, preoperative and postoperative best-corrected visual acuity (BCVA), preoperative and postoperative intraocular pressure (IOP), and postoperative complications were analyzed.

Results: Compared to other presettings the best CCR was achieved by adjusting the color channel to enhance red and by modifying the color profile to create a monochrome image (P<0.01). The same presetting resulted in a highest subjective visibility (P<0.01). Mean preoperative BCVA and 6-month postoperative BCVA (logMAR) were 0.11±0.18 and 0.05±0.19, respectively (p=0.24). Mean preoperative IOP and 6-month postoperative IOP were 13.8±2.8 mmHg and 13.3±3.4 mmHg, respectively (p=0.51). No apparent intra- and post-operative complications were observed.

Conclusion: Color enhancement and achromatization using DAV may offer potential advantages to enhance the visibility of ICG-stained ILM.