Abstract
Purpose :
Femtosecond Laser Assisted Cataract Surgery (FLACS) is a new technology that reduces the amount of ultrasound energy used and allows for a more efficient cataract extraction. The IOP reduction effect of conventional phacoemulsification (PE) is known and a hypothesized cause is ultrasound energy. However, this effect is not established in FLACS. The purpose of our study is to compare the IOP-lowering effect of FLACS versus conventional PE.
Methods :
We conducted a retrospective cohort study on 400 cataract surgeries between February 2014 and November 2015 in a local private practice and ophthalmology ambulatory surgical center. Surgeries were performed by three surgeons. For patients with surgery done on both eyes, information on both eyes were included in the analysis. Demographic information was collected and pre-operative pressure was calculated averaging 1-3 IOP measurements prior to the surgery. Post-operative IOP were measured at 1 month, 3 months, 6 months, 1 year, 2 years and 3 years. Patients without pre-operative IOP, patients with diagnosis of glaucoma and surgeries complicated by vitrectomy were excluded. IOP reduction was compared at each time point using a paired t-test and data was analyzed longitudinally using model based estimation. SAS University 9.4 was used for data analysis.
Results :
338 eyes met the inclusion criteria. The mean pre-operative IOP in eyes undergoing FLACS versus conventional PE was very similar (p=0.78). There was no statistically significant difference in IOP reduction between conventional PE and FLACS at any of the follow-up times (Table 2). Matching subjects for age did not yield different results. Longitudinal analysis showed no statistically significant difference in IOP reduction at last follow-up between conventional PE versus FLACS (p= 0.98). However, we found a strong non-linear relationship between IOP reduction and the follow-up time (p<0.001). Additionally, higher pre-operative pressure was correlated with a bigger reduction in post-operative IOP at all time points (p<0.0001).
Conclusions :
In our sample, there was no long term difference between FLACS and conventional PE in regards to lowering IOP, which could be due to the difference in ultrasound energy being too small between these two modalities. However, there is a strong non-linear relationship between IOP reduction and follow-up time.
This is a 2020 ARVO Annual Meeting abstract.