Less pupil variation in Femtosecond Laser-Assisted Cataract Surgery than Phacoemulsification
Femtosecond laser-assisted cataract surgery (FLACS) emerged as a novel technique in 2009. Since then, this technique has evolved considerably, covering several of the conventional surgical steps previously performed in a manual manner (incisions, lens fragmentation, and capsulotomy). The safety and effectiveness of FLACS is consensually established, with considerable evidence. However, intraoperative miosis has been associated with femtosecond laser-assisted cataract surgery, which renders inherent difficulties regarding nuclear fragmentation, cortex removal, intraocular implantation of the lens, and increases the risk of posterior capsule rupture. This undesired side effect is frequently reported in the vast majority of publications regarding FLACS, which, almost invariably, do not differentiate femtosecond laser based on the pulse pattern, i e, between low and energy pulse femtosecond lasers or do not contemplate low energy pulse at all.
The study by Salgado et al aimed to further investigate on the pupil area changes with low energy pulse FLACS and compare it against the standard phacoemulsification. For this matter, an intraindividual study was performed. This study showed no significant pupil changes, namely myosis, after low-energy FLACS pre-treatment. Comparison between techniques showed less pupil variation in FLACS as compared to CP, more markedly in eyes with comorbidities (particularly with shallow anterior chamber), although non-statistically significant.
A retrospective review of registered surgical data from patients that undergone uncomplicated cataract surgery in a single centre, with randomly assigned femtosecond laser–assisted cataract surgery (FLACS) to one eye and conventional phacoemulsification (CP) to the other, was performed. The recorded pupil images were evaluated at pre and post laser treatment (after suction release) and at several surgical time points for both techniques (FLACS and CP). Pupil areas were calculated and compared in the same eye undergone FLACS (pre vs post laser treatment), between eyes (CP vs FLACS) in the same patient and between groups. Subgroups were built regarding age and ocular comorbidity.
- This study involved a total of 164 eyes of 82 patients. No statistical differences regarding the total duration of surgery (p=0.805) between FLACS and CP.
- Pupil measurements between pre and post laser treatment in the FLACS group showed no statistically significant differences (p=0.107).
- The mean change in pupil area from the beginning until the end of surgery (total variation) was 6.59±2.08 mm2 in the FLACS group and 6.67±2.13 mm2 in the CP group, associated to less narrowing of pupil area with FLACS, although not statistically significant (p=0.080).
- Comorbidity group analysis revealed less, but not significant, pupil narrowing with the FLACS technique (p=0.071).
- No statistically significant differences between FLACS and CP concerning age subgroups were registered.
In conclusion, this intraindividual study provides extended evidence of lack of laser-induced myosis with low-energy FLACS. Furthermore, regarding pupil status, low-energy femtosecond laser-assisted energy seems to compare favorably with conventional phacoemulsification in the presence of certain ocular comorbidities. Although not statistically significant, this difference arises an interesting discussion and, also in line with contemporary literature, it recommends revision of some established, global opinions on FLACS. Further studies on low-energy femtosecond laser-assisted cataract surgery, involving higher samples and rigorous variable control, are in demand for this matter.
Source: Salgado et al; Clinical Ophthalmology 2023:17
https://doi.org/10.2147/OPTH.S399788
