Abstract
Purpose: :
To determine the benefits of reduced laser pulse width on the effectiveness of anterior laser capsulotomy and phacofragmentation.
Methods: :
Patients presenting for cataract surgery were recruited on to this study after signing the IRB approved informed consent document. Eyes were treated with a clinical prototype laser that had previously been used for data collection but was retro-fitted with a femtosecond laser to replace the picosecond laser previously used. Surgeon scored ease of opening of the capsulotomy and the reduction in the use of ultrasound compared to conventional phacoemulsification were used as measures of the benefit of the shorter pulse laser.
Results: :
85 eyes of 85 patients were enrolled in the study, of which 81 proceeded to laser cataract surgery. On a scale of 1-10, ease of opening the capsulotomy was scored at 10 in 77.5% of cases compared to 38.7% with the picosecond laser and a score of 8 or greater was achieved in 93% of cases compared to 84% with the picosecond laser (p<0.001). Mean (SD) cumulative dissipated (ultrasound) energy for the laser and control groups respectively was 2.28 (1.71) and 4.38 (2.38) for Grade 1 cataract (p=0.210), 1.38 (3.15) and 8.20 (6.13) for Grade 2 (p<0.001), 5.83 (6.52) and 15.24 (12.95) for Grade 3 (p<0.001) and 19.68 (16.33) and 41.18 (24.68) for Grade 4 (p=0.021). Reductions in ultrasound energy for femtosecond and picosecond lasers compared to conventional phacoemulsification respectively were 83.2% and 63.7% for Grade 2, 61.7% and 39.2% for Grade 3 and 52.2% and 41.6% for Grade 4.
Conclusions: :
The use of a shorter pulse laser improved the ease of opening of the anterior capsulotomy with a higher percentage being totally detached from the remaining capsule. Phacofragmentation was significantly better than conventional ultrasound in all categories but Grade 1 where total numbers were very small. In all grades but Grade 1 the shorter pulse laser showed higher percentage reduction in ultrasound energy.
Clinical Trial: :
http://www.clinicaltrials.gov NCT01062464
Keywords: cataract • laser • refractive surgery: other technologies