Low-energy femtosecond laser lens fragmentation techniques for cataract

Femtosecond laser has become an important tool in cataract surgery due to its precision and minimally invasive nature. However, the strong scattering properties of the lens limit surgical efficiency, especially when it comes to effectively cutting highly opaque and hard cataracts with femtosecond laser. This study proposes a method for achieving optical transparency in opaque lenses through tartrazine treatment. This treatment method can effectively enhance the deep focusing ability of femtosecond laser, improving cutting quality and efficiency when used in femtosecond-assisted cataract surgery (FLACS). The results demonstrate that tartrazine treatment significantly enhanced the transparency of the lens across varying degrees of opacity. The transmittance of 1036 nm light through the highly opaque cataract lens was increased by approximately 60 %, and optical coherence tomography (OCT) can clearly image the posterior capsule of the opaque lens. Furthermore, the laser nuclear fragmentation energy was reduced from 15 μJ to 6 μJ. Optical coherence elastography (OCE) measurements revealed that the Young's modulus of the treated lens decreased from 49.24 ± 3.30 kPa to 37.92 ± 4.68 kPa. We propose that tartrazine treatment can enhance the optical transparency of the opaque lens while softening the lens. The tartrazine treatment has the potential to reduce laser-induced damage during FLACS, improve the cutting efficiency of femtosecond laser for highly opaque and hard cataracts, and decrease the incidence of postoperative complications.