Looking At Cataract Surgeries

Looking At Cataract Surgeries - For the past 20 years, phacoemulsification cataract surgery (PHACO) has been the gold standard for cataract surgery.

PHACO removes the cloudy lens (cataract) using ultrasound energy through a small corneal incision. The corneal incision is made using a single-use surgical blade.

An intraocular lens implant (IOL) is then inserted into the eye to replace the removed cloudy lens.

The IOL can be monofocal or multifocal. This procedure is quick, safe and has produced excellent results.

Although it uses ultrasound technology, it is confusingly also known as the “laser” method to distinguish it from an outdated manual cataract surgery method known as extra-capsular cataract extraction (ECCE).

Femtosecond laser assisted cataract surgery (FLACS) is a more recent addition to the process of PHACO whereby a few of the manual surgical steps of the PHACO procedure are performed using femtosecond laser technology.

The femtosecond laser technology has been used in laser refractive surgery (e.g. LASIK) for more than 20 years.

Since the corneal incision is made using the femtosecond laser instead of a surgical blade, FLACS is sometimes called “bladeless laser cataract surgery”. Although it is meant to be “bladeless”, a blunt surgical instrument, or in some cases, a surgical blade, is required to assist in the opening of the corneal incision.

The surgical steps, which are done by FLACS are 1) the corneal incision, 2) the opening of the anterior lens capsule (capsulotomy), and 3) the division of the cataract into smaller portions (lens fragmentation).

Since these steps are done by a laser guided scan for higher precision, FLACS is thought to offer better surgical outcome.

Other than these three surgical steps, the rest of the FLACS procedure is identical to PHACO.

Since the corneal incision is made using the femtosecond laser instead of a surgical blade, FLACS is sometimes called “bladeless laser cataract surgery”. Although it is meant to be “bladeless”, a blunt surgical instrument, or in some cases, a surgical blade, is required to assist in the opening of the corneal incision.

An experienced ophthalmologist can perform a PHACO procedure in 15 minutes.

FLACS requires a femtosecond laser machine, which may be situated in a separate room from the cataract operating room. Since FLACS requires additional steps, it typically adds an extra 15 minutes to the total surgical time.

So, the entire cataract operation with FLACS may take up to 30 mins in total.

What are the advantages of FLACS?

• Accurate corneal incision – FLACS can create accurately and precisely placed corneal incisions, which is useful in the surgical correction of astigmatism.

• More precise and well-centred capsulotomy – A well centred capsulotomy may help in better centration of the lens implant, which is important in achieving more accurate refractive outcome. This is desirable if the patient wants to be spectacles-free after the surgery.

• Lens fragmentation – FLACS helps to break down the cataract, resulting in less ultrasound energy needed to remove the cataract. This is particularly advantageous in a mature or hard cataract. Potentially, this will reduce post-operative inflammation and may result in faster recovery.

What are the extra risks of FLACS compared with PHACO?

• Elevation of intraocular pressure (IOP) and pupil constriction – FLACS requires the use of a vacuum suction cup.

This increases the intraocular pressure (IOP) inside the eye momentarily, which may cause optic nerve damage in patients with glaucoma.

Also, the docking and the laser capsulotomy may cause pupil constriction, which can sometimes make the latter part of the surgery more difficult. It can also cause bruising of the eye.

• Lens capsule complication – PHACO uses a delicate manual method to create an opening at the anterior lens capsule (capsulotomy). This produces a smooth edge circular opening for the subsequent removal of the cataract.

FLACS uses multiple laser shots to perforate the anterior lens capsule to create the opening. This results in a serrated edge (like the edge of a postage stamp), making the capsule more easily torn during the cataract procedure. A torn capsule can complicate subsequent cataract removal and intraocular lens implantation.

• Other risks: According to the largest study in the world comparing FLACS and PHACO to date, the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO) study published in 2016, FLACS is associated with a higher incidence of complications (FLACS 3.8 % vs. PHACO 2.3 %).

Complications include corneal oedema (swelling), slight reduced initial vision, eye inflammation (uveitis), and high intra ocular pressure. However, most of these complications were transient.

Is FLACS better than PHACO?

The jury is still out on this. Some cataract refractive surgeons think that FLACS offers more precise refractive outcome, which may result in higher glasses independence, especially following multifocal lens implant.

On the other hand, others feel that FLACS offers no significant advantage and does not justify the extra cost.

According to the EUREQUO study, there is no evidence that FLACS is superior in comparison to PHACO in terms of visual outcome. There was a marginally higher complication rates for FLACS in comparison to PHACO.

At present, the advantage of FLACS over PHACO is minimal. However, with time and as technology advances, FLACS may become better than PHACO.