Cataract surgery is frequently performed in patients with glaucoma. To this day, the debate continues whether FLACS is equivalent or superior to manual cataract surgery. When we think about performing FLACS in patients with Glaucoma we must take into account that this procedure has the added step of suction docking during pretreatment, which has been reported in several studies to raise IOP. 10,11,12 In our study, we assess short-term IOP changes and surgical outcomes when using the femtosecond laser pretreatment in patients with different types of glaucoma undergoing cataract surgery alone or in combination with glaucoma surgery.
In our patients we found similar surgical outcomes to those published with traditional manual cataract surgery regarding IOP, VA, and VF, with the added advantage of femtosecond laser precision.13 Suction was well tolerated in glaucomatous eyes during surgery, showing no significant mean IOP raise immediately after suction docking or up to our 90-day final follow-up. This contrasts with previous studies of FLACS performed in glaucomatous eyes. 10, 11,12,14
In a prospective study by Darrian-Smith, 143 eyes (30% with glaucoma) were studied by measuring IOP with a rebound tonometer before and after suction docking during FLACS with Catalys Precision Laser System with Liquid Optics Interface (Abbott Medical Optics, Inc.). Their results showed a transient IOP increase from baseline that was significantly higher in glaucomatous eyes; after removal of suction the IOP levels decreased in both groups, but remained above preoperative values and were higher in eyes with glaucoma. 11
A retrospective case series study conducted by Shah evaluated the long term IOP changes in 504 eyes, of which 278 had glaucoma, after FLACS. They reported that both control and glaucomatous eyes had an initial IOP spike, followed by a sustained reduction from baseline up to 3 years follow up, this decrease was greater and lasted longer in eyes with glaucoma than in healthy control eyes.12
In our study, patients who underwent FLACS with IOL implantation alone did not present an IOP elevation during surgery or in the first 30 days of follow up, instead, they showed a lower mean IOP at day 90 after surgery in comparison to baseline.
Regarding eyes who underwent FLACS with IOL implantation and glaucoma surgery, there was an IOP reduction from day 1 after surgery, that lasted up to 90 days with a 6 mmHg decrease from baseline. This group also showed a significant reduction in topical glaucoma medication requirement, which is expected in combined glaucoma surgery.
When comparing FLACS outcomes, we must consider that different femtosecond systems will have different characteristics, therefore, they are not totally comparable to one another; even in the same femtosecond system, different types of suction docking interfaces can have different outcomes in IOP changes. 14
No complications that have been previously reported in FLACS, like incomplete capsulotomy, tears in anterior capsule or posterior capsule ruptures were recorded during any of the surgeries in our study.15,16,17
BCVA was significantly improved in both groups. No changes in VF were recorded, but longer follow up is necessary to evaluate the real impact of this procedure in glaucoma progression.
A small sample with a short follow-up are the main limitations of our study, which allows for a descriptive case series instead of a more thorough statistical analysis. A larger sample, with a longer follow up, along with a control group would allow an analysis that could give us more conclusive results regarding the safety and outcomes of Femtosecond Laser alone or in combination with glaucoma surgery in patients with glaucoma. To our knowledge outcomes of FLACS used in combination with glaucoma surgery had not been previously reported. The use of FLACS in eyes with previous glaucoma surgery or along with Microinvasive Glaucoma Surgery (MIGS) has not been reported and could be an interesting prospect to explore.