A randomized Comparison of laparoscopic LEns defogging using Anti-fog solution, waRm saline, and chlorhexidine solution (CLEAR)



Current literature demonstrates a lack of comparative in vivo studies regarding laparoscopic lens fogging (LLF). This randomized trial aimed to compare 3 popular methods of minimizing or reducing LLF in laparoscopic surgery by heating the lens using warm saline, applying anti-fog solution to the lens, and rubbing the lens with chlorhexidine solution.


Ninety-six participants underwent randomization to be allocated in control (n = 24), warm saline (n = 24), anti-fog solution (n = 24), and chlorhexidine groups (n = 24). The primary outcome measure was the severity of LLF during the first 3 min after laparoscope insertion into the abdominal cavity. The severity of LLF was rated on a 10-point visual clarity scale ranging from 0 (clearest) to 10 (foggiest). The secondary outcome measures were (1) the severity of LLF during the remaining operative time other than the first 3 min, (2) the number of lens cleansings, and (3) the total time required to clean the lens.


Lens fogging during the first 3 min and remaining operative time other than the first 3 min was significantly decreased in the warm saline group compared to that in the other 3 groups (all, P < 0.001). In post hoc analysis, the anti-fog solution group was significantly foggier than the warm saline group, but clearer than the chlorhexidine and control groups. The number of lens cleansings and total time required to clean the lens were significantly lower in the warm saline and anti-fog solution groups than in the chlorhexidine and control groups (all, P < 0.05).


The use of warm saline leads to significantly fewer fogging events than the use of anti-fog solution or chlorhexidine solution, resulting in an improved continuity of surgery.

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Correspondence to Taejong Song.

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Drs. Taejong Song and Dong Hee Lee have no conflicts of interest or financial ties to disclose.

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Song, T., Lee, D.H. A randomized Comparison of laparoscopic LEns defogging using Anti-fog solution, waRm saline, and chlorhexidine solution (CLEAR). Surg Endosc 34, 940–945 (2020) doi:10.1007/s00464-019-06852-5

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  • Laparoscopy
  • Laparoscopic lens defogging
  • Fogging