Capsulorhexis edge irregularity increases with femtosecond laser energy

This prospective study found a higher degree of capsulorhexis edge irregularity using the femtosecond laser at increasing energy settings. The authors also found that use of the laser resulted in better capsulorhexis geometry and circularity than manual capsulorhexis, although the cut surface was smoother with the manual technique.

I found this paper interesting because we only hear in presentations about how capsulotomy performed with a laser is superior to manual capsulotomy.

The authors used scanning electron microscopy (SEM) to evaluate capsulorhexis-cut quality obtained during femtosecond laser–assisted cataract surgery at different energy settings and with a standard manual technique.

They examined 60 capsulorhexes. Twelve were obtained using the conventional manual technique and 12 with each of the following femtosecond laser energy settings: 7.0 mJ, 13.5 mJ, 14.0 mJ and 15.0 mJ.

They found a significant correlation between degree of irregularity and increasing energy (P < 0.001).

Capsulorhexes performed with the femtosecond laser at all energy settings were perfectly circular with negligible deformation. The manual group had a significantly higher thickness of the capsulorhexis edge than the laser groups, while the group with the lowest laser energy setting had a significantly lower thickness compared to the manual group and the laser groups with higher energy settings (P < 0.001).

The authors conclude that low-energy femtosecond laser settings provide a better cut surface, even for capsulorhexis creation, which is probably correlated with the reduction of cataract surgery complications.

They say these promising results should encourage studies on the optimum spot size and pulse-laser energy for maintaining the advantages of the manual technique while adding the advantages of the femtosecond laser.