Cataract Surgery · Surgical Technique Series
A steady hand,
or a computer-guided
laser. Not the same case.
A femtosecond laser can now cut the corneal incisions, create the capsulotomy and pre-fragment the cataract before a surgeon's phaco probe ever enters the eye. That is a real, image-guided change in technique — not automatically a better outcome. Here is what the laser actually automates, and what the comparative trials say about whether it matters for a given patient.
automates
platforms entered practice
in most health systems
Section 01 — Two Philosophies
Freehand,
or image-guided.
Both finish the same way.
Patients see "laser cataract surgery" advertised as an upgrade and assume it replaces the operation entirely. It does not. Every cataract, laser-assisted or not, still ends with a surgeon aspirating the lens material and implanting an IOL. What a femtosecond laser changes is only the setup: three specific steps that used to be done entirely by hand are instead planned on a computer and executed by a laser docked to the eye, before conventional phacoemulsification takes over.
Manual (conventional) phacoemulsification is the technique that has been performed on hundreds of millions of eyes worldwide: the surgeon creates a continuous curvilinear capsulorhexis (CCC) freehand with a bent needle or capsulorhexis forceps, then sculpts and chops the cataractous nucleus using ultrasound energy delivered directly through the phaco probe, aspirating the fragments as they are broken up.
Femtosecond laser-assisted cataract surgery (FLACS) inserts an extra, image-guided stage before that: an OCT-integrated femtosecond laser platform — commercial systems include LenSx, Catalys, LENSAR and Victus — is docked to the eye under low suction, images the anterior segment, and then fires patterned laser pulses to cut the corneal incisions, a precisely sized and centered capsulotomy, and a fragmentation or "chop" pattern through the nucleus. The surgeon then proceeds to conventional phacoemulsification to remove the pre-treated pieces.
FLACS does not replace phacoemulsification — it automates three preparatory steps (incisions, capsulotomy, nucleus fragmentation) using an image-guided laser instead of a surgeon's hand, then hands the case back for conventional ultrasound aspiration. The laser's genuine, well-documented advantage is more consistent capsulotomy size and centration, and less ultrasound energy needed to finish the case. What it has not consistently delivered, across large comparative trials, is a proven visual-acuity or overall-safety advantage for the average cataract patient. The precision earns its price mainly when a centration-sensitive premium IOL or integrated astigmatism correction is part of the plan.
Section 02 — Interactive
Where the precision
actually shows up: the capsulotomy.
Toggle between the two techniques and turn up case difficulty — a smaller pupil, a denser cataract, a poorer red reflex — and watch what happens to the capsulotomy ring and its centration on the lens below. This is the one step where the laser's consistency is least dependent on how hard the case is.
A perfectly circular, correctly sized and well-centered capsulotomy matters because the capsular bag is what holds the IOL in place afterward. If the rim overlaps the optic unevenly, the lens can tilt or shift off-axis over the following weeks as the capsule contracts — a decentration risk that a monofocal IOL tolerates well, but that a diffractive multifocal or extended depth-of-focus (EDOF) optic is measurably less forgiving of, since their concentric diffractive rings depend on staying centered on the visual axis. Laser capsulotomies have been shown in multiple measured series to be more consistent in diameter and circularity than freehand capsulorhexis, and that consistency holds up better as case difficulty rises — a small pupil, a dense brunescent lens, or a poor red reflex all make a freehand rhexis harder to judge, while a well-imaged laser pass is comparatively unaffected by surgeon fatigue or case-to-case variation.
Section 03 — Where Each Technique Wins
The case, the setting
and the budget
decide more than the label.
Neither technique is universally "better." Which one makes sense depends heavily on the specific case, the surgical setting, and what IOL is planned. The table below is deliberately unflattering to both, in each direction.
| Case or setting factor | Manual phaco | FLACS |
|---|---|---|
| Dense/brunescent cataract, poor red reflex | Freehand capsulotomy documented to carry higher tear risk when the capsule is hard to see | Laser imaging can struggle through opacity; may require conversion to manual capsulotomy for that step |
| Small pupil / weak zonules | Freehand rhexis technically harder; more capsular tag risk in difficult cases | Docking and imaging require adequate pupil size; small pupils can limit the laser's working field |
| High-volume / outreach camp lists | No capital equipment or per-case laser fee — the technique that scales to high-volume, cost-sensitive programs | Capital and licensing cost make it impractical where throughput and per-case cost are the binding constraint |
| Astigmatism correction planned | Relies on manual limbal relaxing incisions or toric IOL alignment marks | Can cut precise arcuate incisions in the same laser pass, integrated with toric IOL planning |
| Diffractive multifocal / EDOF IOL planned | Capsulotomy centration depends on surgeon skill and case difficulty | More consistent capsulotomy size and centration — the scenario where laser precision is most likely to matter clinically |
| Practice capital budget | Standard phaco machine only | Requires the added femtosecond platform investment, typically recovered through a patient-facing premium fee |
Read across that table and a pattern emerges: FLACS earns its keep in centration-sensitive, premium-IOL, well-resourced practice settings, while manual phaco remains the technique that keeps cataract surgery affordable and scalable everywhere else — including the high-volume outreach and public-sector programs that perform the overwhelming majority of cataract surgery worldwide, discussed in more depth in our guide to the global cataract backlog and the manual small-incision technique that powers most of it.
Section 04 — How the Laser Step Actually Works
Dock, image,
then fire —
three patterns, one pass.
A femtosecond laser produces extremely short pulses (on the order of quadrillionths of a second) tightly focused to a point, causing photodisruption — a microscopic plasma bubble that separates tissue — without meaningfully heating the surrounding structures. Cataract platforms combine this with real-time OCT imaging so the surgeon can see exactly where each pattern will land before firing.
None of this laser pretreatment uses ultrasound; that energy is reserved entirely for the phacoemulsification step that follows once the pre-cut nucleus is ready to be aspirated. The laser pass itself typically adds a modest amount of extra time to the overall procedure — commonly cited in the range of several extra minutes — since the patient must be moved from the laser suite or a shared laser-and-phaco room to complete the case with conventional aspiration.
Section 05 — The Evidence
What the comparative
trials actually show.
A genuine, fairly large body of comparative literature now exists on FLACS versus conventional phacoemulsification, including a Cochrane systematic review and a meta-analysis pooling data across tens of thousands of eyes. The pattern that emerges is consistent: real, measurable process differences, without a clear final-outcome advantage for the average patient.
Illustrative visualisation of the direction reported across the comparative literature (Cochrane review, Popovic et al. meta-analysis and related series) — see References for source studies. Not pooled meta-analytic effect sizes.
The Cochrane Database of Systematic Reviews has published a review comparing laser-assisted cataract surgery against standard ultrasound phacoemulsification, concluding that the certainty of evidence for most patient-important outcomes — including uncorrected and corrected visual acuity — is low to moderate, with little or no clear difference between the two techniques, while noting FLACS's reduction in effective phaco time and cumulative dissipated energy as a consistently reproduced process finding. A separate meta-analysis by Popovic and colleagues, pooling comparative data across many thousands of eyes, reported the same broad pattern: comparable final visual acuity between groups, a reduction in ultrasound energy delivered with FLACS, and capsulotomy metrics (size variability, circularity) that measured more consistent with the laser.
Some of the earliest published clinical work on femtosecond laser capsulotomy, including reporting by Nagy and colleagues describing initial clinical use of an intraocular femtosecond laser in cataract surgery, established the basic feasibility and capsulotomy-precision case for the technology before it reached wide commercial adoption. Later series examining anterior capsule integrity specifically have found that capsule tear or tag rates with the laser step were higher in some early adopter cohorts, a pattern generally attributed to a learning-curve effect on laser settings and patient selection rather than an intrinsic flaw in the technology.
pre-treats before phaco
pretreatment time
for the laser steps themselves
Section 06 — Risk, Honestly Stated
Both techniques
carry real trade-offs.
Neither list is empty.
A comparison that only lists FLACS's price tag or only lists manual phaco's dependence on surgeon skill is not being straight with the reader. Both have a documented, real trade-off profile.
| Risk / trade-off | Manual phaco | FLACS |
|---|---|---|
| Capsule tear / tag | Documented risk from freehand capsulorhexis, especially in dense cataracts or with less experienced surgeons | Some early-adoption series reported higher rates from the laser-cut edge; gap has narrowed with surgeon experience in later series |
| Docking / suction issues | Not applicable | Loss of suction during docking can leave an incomplete or irregular capsulotomy requiring manual completion |
| Intraoperative pupil constriction | Can occur from mechanical stimulation; managed at closure with agents such as intracameral carbachol | The suction-docking step has been associated in some series with additional pupillary constriction, occasionally requiring pupil-expansion measures |
| Ultrasound energy delivered | Full energy required to emulsify an untreated nucleus | Pre-fragmentation reliably reduces effective phaco time and cumulative dissipated energy in most comparative studies |
| Total cost to patient | Lowest — typically covered as standard cataract surgery | Additional platform and per-case cost, usually billed as a refractive add-on not covered by insurance or public health schemes |
| Proven visual-acuity advantage | Excellent, well-established outcomes at population scale | Comparable in most head-to-head trials; laser precision has not translated into a consistently proven visual-acuity edge for general cataract populations |
Section 07 — Where the Decision Actually Gets Made
The IOL plan decides it,
not the marketing term.
In practice, the choice of technique tracks closely with what IOL is planned and what surgical volume the practice or program is built around — more than it tracks with any inherent superiority of one technique over the other.
A private-pay patient choosing a diffractive trifocal IOL to reduce dependence on glasses at every distance is exactly the case where capsulotomy centration matters most, since a diffractive optic decentered even modestly can degrade contrast sensitivity and increase glare. Paying an out-of-pocket premium for FLACS's more consistent capsulotomy in that scenario is a defensible, evidence-aligned choice — the precision is being spent where the optic is least forgiving of imprecision.
A high-volume outreach or camp-based cataract program treating hundreds of patients with monofocal IOLs, where the health economics literature consistently shows manual small-incision technique delivering excellent, high-throughput outcomes at a fraction of the per-case cost, is exactly the setting where a femtosecond platform's capital and licensing cost would not translate into a meaningfully better result for the patient in front of the surgeon that day.
The inverse framing is just as valid: a patient receiving a standard monofocal IOL, with a routine pupil and a clear red reflex, is very unlikely to notice a difference in final vision whichever technique is used — which is exactly what the comparative trials, on balance, report.
Section 08 — The Agaaz Range
What sits in the tray
— regardless of the platform.
Agaaz Ophthalmics does not manufacture femtosecond laser platforms, but the intraocular case built around every cataract extraction — laser-pretreated or entirely manual — runs through the same anterior chamber protection, capsular visualization and infection-prophylaxis steps. GMP-manufactured, specified below by what they are, not how they are positioned.
If intraoperative pupil constriction complicates a case — a documented risk with either technique, discussed in our guide to intracameral carbachol for miosis control — the same closing protocol applies irrespective of platform. View the complete portfolio →
Section 09 — FAQ
Frequently asked questions
about FLACS.
FLACS uses an image-guided femtosecond laser, docked to the eye and steered by built-in OCT imaging, to perform three steps before conventional phacoemulsification begins: the corneal incisions, the anterior capsulotomy (the circular opening made in the lens capsule), and fragmentation or softening of the cataractous nucleus. The laser does not remove the cataract itself — a surgeon still completes the case with standard ultrasound phacoemulsification and lens implantation immediately afterward.
In manual phacoemulsification, the surgeon creates the capsulotomy freehand with a bent needle or forceps (a continuous curvilinear capsulorhexis), then chops and emulsifies the entire nucleus using ultrasound energy delivered directly by the phaco probe. In FLACS, the laser pre-cuts the capsulotomy to a computer-planned size and shape and pre-fragments the nucleus into segments before the phaco probe is ever introduced, so less ultrasound energy is needed to finish removing the lens.
Not consistently. A Cochrane systematic review and a large meta-analysis pooling comparative studies have both found low-to-moderate certainty evidence of little or no difference in final best-corrected visual acuity between FLACS and conventional manual phacoemulsification in general cataract populations. What FLACS reliably improves is the size, shape and centration consistency of the capsulotomy itself and the amount of ultrasound energy needed to finish the case — advantages that matter most when a centration-sensitive premium IOL is planned, not a guaranteed sharper outcome for every patient.
Overall complication rates are broadly similar between the two techniques in large comparative series, but the risk profile is different rather than one being simply lower. Some early FLACS series reported higher rates of anterior capsule tears or tags from the laser-cut capsulotomy edge, particularly during a surgeon's learning curve; larger, more recent series suggest this gap narrows with experience. FLACS also introduces its own limitations — a suction-based docking step that can occasionally cause an incomplete capsulotomy requiring manual completion, and difficulty imaging through a very dense cataract or a poor red reflex.
A femtosecond laser platform is a separate, expensive piece of capital equipment on top of a standard phaco machine, and most platforms also charge a per-case licensing or consumable fee. In most health systems, including Medicare in the US and most public and private insurance internationally, FLACS is billed as a refractive add-on rather than a medically necessary step, so the incremental cost is typically paid out of pocket by the patient rather than reimbursed.
Most cataract surgery worldwide, including the large majority of high-volume and outreach programs, is performed safely and effectively with manual or standard phacoemulsification and monofocal IOLs, where FLACS's main advantage — capsulotomy precision — has less practical impact. FLACS is most often selected when a diffractive multifocal or extended depth-of-focus IOL is planned, since those optics are more sensitive to capsulotomy size and centration, or when integrated astigmatism-correcting laser incisions are wanted alongside a toric IOL.
The docking and suction step needed to stabilize the eye under the laser has been associated in some series with transient intraoperative pupil constriction, which can complicate the remainder of the case if it is not anticipated. Loss of suction mid-treatment can leave an incomplete or irregular capsulotomy that the surgeon then has to complete manually. Laser imaging can also struggle to see through a very dense, brunescent cataract or a poor red reflex, occasionally forcing a conversion to a fully manual technique for that step.
References & Evidence Base
Peer-reviewed
citations.
Continue Reading
Related guides
from Beyond Vision.
Cataract Surgery · Surgical Technique Series
A steady hand,
or a computer-guided
laser. Not the same case.
A femtosecond laser can now cut the corneal incisions, create the capsulotomy and pre-fragment the cataract before a surgeon's phaco probe ever enters the eye. That is a real, image-guided change in technique — not automatically a better outcome. Here is what the laser actually automates, and what the comparative trials say about whether it matters for a given patient.
automates
platforms entered practice
in most health systems
Section 01 — Two Philosophies
Freehand,
or image-guided.
Both finish the same way.
Patients see "laser cataract surgery" advertised as an upgrade and assume it replaces the operation entirely. It does not. Every cataract, laser-assisted or not, still ends with a surgeon aspirating the lens material and implanting an IOL. What a femtosecond laser changes is only the setup: three specific steps that used to be done entirely by hand are instead planned on a computer and executed by a laser docked to the eye, before conventional phacoemulsification takes over.
Manual (conventional) phacoemulsification is the technique that has been performed on hundreds of millions of eyes worldwide: the surgeon creates a continuous curvilinear capsulorhexis (CCC) freehand with a bent needle or capsulorhexis forceps, then sculpts and chops the cataractous nucleus using ultrasound energy delivered directly through the phaco probe, aspirating the fragments as they are broken up.
Femtosecond laser-assisted cataract surgery (FLACS) inserts an extra, image-guided stage before that: an OCT-integrated femtosecond laser platform — commercial systems include LenSx, Catalys, LENSAR and Victus — is docked to the eye under low suction, images the anterior segment, and then fires patterned laser pulses to cut the corneal incisions, a precisely sized and centered capsulotomy, and a fragmentation or "chop" pattern through the nucleus. The surgeon then proceeds to conventional phacoemulsification to remove the pre-treated pieces.
FLACS does not replace phacoemulsification — it automates three preparatory steps (incisions, capsulotomy, nucleus fragmentation) using an image-guided laser instead of a surgeon's hand, then hands the case back for conventional ultrasound aspiration. The laser's genuine, well-documented advantage is more consistent capsulotomy size and centration, and less ultrasound energy needed to finish the case. What it has not consistently delivered, across large comparative trials, is a proven visual-acuity or overall-safety advantage for the average cataract patient. The precision earns its price mainly when a centration-sensitive premium IOL or integrated astigmatism correction is part of the plan.
Section 02 — Interactive
Where the precision
actually shows up: the capsulotomy.
Toggle between the two techniques and turn up case difficulty — a smaller pupil, a denser cataract, a poorer red reflex — and watch what happens to the capsulotomy ring and its centration on the lens below. This is the one step where the laser's consistency is least dependent on how hard the case is.
A perfectly circular, correctly sized and well-centered capsulotomy matters because the capsular bag is what holds the IOL in place afterward. If the rim overlaps the optic unevenly, the lens can tilt or shift off-axis over the following weeks as the capsule contracts — a decentration risk that a monofocal IOL tolerates well, but that a diffractive multifocal or extended depth-of-focus (EDOF) optic is measurably less forgiving of, since their concentric diffractive rings depend on staying centered on the visual axis. Laser capsulotomies have been shown in multiple measured series to be more consistent in diameter and circularity than freehand capsulorhexis, and that consistency holds up better as case difficulty rises — a small pupil, a dense brunescent lens, or a poor red reflex all make a freehand rhexis harder to judge, while a well-imaged laser pass is comparatively unaffected by surgeon fatigue or case-to-case variation.
Section 03 — Where Each Technique Wins
The case, the setting
and the budget
decide more than the label.
Neither technique is universally "better." Which one makes sense depends heavily on the specific case, the surgical setting, and what IOL is planned. The table below is deliberately unflattering to both, in each direction.
| Case or setting factor | Manual phaco | FLACS |
|---|---|---|
| Dense/brunescent cataract, poor red reflex | Freehand capsulotomy documented to carry higher tear risk when the capsule is hard to see | Laser imaging can struggle through opacity; may require conversion to manual capsulotomy for that step |
| Small pupil / weak zonules | Freehand rhexis technically harder; more capsular tag risk in difficult cases | Docking and imaging require adequate pupil size; small pupils can limit the laser's working field |
| High-volume / outreach camp lists | No capital equipment or per-case laser fee — the technique that scales to high-volume, cost-sensitive programs | Capital and licensing cost make it impractical where throughput and per-case cost are the binding constraint |
| Astigmatism correction planned | Relies on manual limbal relaxing incisions or toric IOL alignment marks | Can cut precise arcuate incisions in the same laser pass, integrated with toric IOL planning |
| Diffractive multifocal / EDOF IOL planned | Capsulotomy centration depends on surgeon skill and case difficulty | More consistent capsulotomy size and centration — the scenario where laser precision is most likely to matter clinically |
| Practice capital budget | Standard phaco machine only | Requires the added femtosecond platform investment, typically recovered through a patient-facing premium fee |
Read across that table and a pattern emerges: FLACS earns its keep in centration-sensitive, premium-IOL, well-resourced practice settings, while manual phaco remains the technique that keeps cataract surgery affordable and scalable everywhere else — including the high-volume outreach and public-sector programs that perform the overwhelming majority of cataract surgery worldwide, discussed in more depth in our guide to the global cataract backlog and the manual small-incision technique that powers most of it.
Section 04 — How the Laser Step Actually Works
Dock, image,
then fire —
three patterns, one pass.
A femtosecond laser produces extremely short pulses (on the order of quadrillionths of a second) tightly focused to a point, causing photodisruption — a microscopic plasma bubble that separates tissue — without meaningfully heating the surrounding structures. Cataract platforms combine this with real-time OCT imaging so the surgeon can see exactly where each pattern will land before firing.
None of this laser pretreatment uses ultrasound; that energy is reserved entirely for the phacoemulsification step that follows once the pre-cut nucleus is ready to be aspirated. The laser pass itself typically adds a modest amount of extra time to the overall procedure — commonly cited in the range of several extra minutes — since the patient must be moved from the laser suite or a shared laser-and-phaco room to complete the case with conventional aspiration.
Section 05 — The Evidence
What the comparative
trials actually show.
A genuine, fairly large body of comparative literature now exists on FLACS versus conventional phacoemulsification, including a Cochrane systematic review and a meta-analysis pooling data across tens of thousands of eyes. The pattern that emerges is consistent: real, measurable process differences, without a clear final-outcome advantage for the average patient.
Illustrative visualisation of the direction reported across the comparative literature (Cochrane review, Popovic et al. meta-analysis and related series) — see References for source studies. Not pooled meta-analytic effect sizes.
The Cochrane Database of Systematic Reviews has published a review comparing laser-assisted cataract surgery against standard ultrasound phacoemulsification, concluding that the certainty of evidence for most patient-important outcomes — including uncorrected and corrected visual acuity — is low to moderate, with little or no clear difference between the two techniques, while noting FLACS's reduction in effective phaco time and cumulative dissipated energy as a consistently reproduced process finding. A separate meta-analysis by Popovic and colleagues, pooling comparative data across many thousands of eyes, reported the same broad pattern: comparable final visual acuity between groups, a reduction in ultrasound energy delivered with FLACS, and capsulotomy metrics (size variability, circularity) that measured more consistent with the laser.
Some of the earliest published clinical work on femtosecond laser capsulotomy, including reporting by Nagy and colleagues describing initial clinical use of an intraocular femtosecond laser in cataract surgery, established the basic feasibility and capsulotomy-precision case for the technology before it reached wide commercial adoption. Later series examining anterior capsule integrity specifically have found that capsule tear or tag rates with the laser step were higher in some early adopter cohorts, a pattern generally attributed to a learning-curve effect on laser settings and patient selection rather than an intrinsic flaw in the technology.
pre-treats before phaco
pretreatment time
for the laser steps themselves
Section 06 — Risk, Honestly Stated
Both techniques
carry real trade-offs.
Neither list is empty.
A comparison that only lists FLACS's price tag or only lists manual phaco's dependence on surgeon skill is not being straight with the reader. Both have a documented, real trade-off profile.
| Risk / trade-off | Manual phaco | FLACS |
|---|---|---|
| Capsule tear / tag | Documented risk from freehand capsulorhexis, especially in dense cataracts or with less experienced surgeons | Some early-adoption series reported higher rates from the laser-cut edge; gap has narrowed with surgeon experience in later series |
| Docking / suction issues | Not applicable | Loss of suction during docking can leave an incomplete or irregular capsulotomy requiring manual completion |
| Intraoperative pupil constriction | Can occur from mechanical stimulation; managed at closure with agents such as intracameral carbachol | The suction-docking step has been associated in some series with additional pupillary constriction, occasionally requiring pupil-expansion measures |
| Ultrasound energy delivered | Full energy required to emulsify an untreated nucleus | Pre-fragmentation reliably reduces effective phaco time and cumulative dissipated energy in most comparative studies |
| Total cost to patient | Lowest — typically covered as standard cataract surgery | Additional platform and per-case cost, usually billed as a refractive add-on not covered by insurance or public health schemes |
| Proven visual-acuity advantage | Excellent, well-established outcomes at population scale | Comparable in most head-to-head trials; laser precision has not translated into a consistently proven visual-acuity edge for general cataract populations |
Section 07 — Where the Decision Actually Gets Made
The IOL plan decides it,
not the marketing term.
In practice, the choice of technique tracks closely with what IOL is planned and what surgical volume the practice or program is built around — more than it tracks with any inherent superiority of one technique over the other.
A private-pay patient choosing a diffractive trifocal IOL to reduce dependence on glasses at every distance is exactly the case where capsulotomy centration matters most, since a diffractive optic decentered even modestly can degrade contrast sensitivity and increase glare. Paying an out-of-pocket premium for FLACS's more consistent capsulotomy in that scenario is a defensible, evidence-aligned choice — the precision is being spent where the optic is least forgiving of imprecision.
A high-volume outreach or camp-based cataract program treating hundreds of patients with monofocal IOLs, where the health economics literature consistently shows manual small-incision technique delivering excellent, high-throughput outcomes at a fraction of the per-case cost, is exactly the setting where a femtosecond platform's capital and licensing cost would not translate into a meaningfully better result for the patient in front of the surgeon that day.
The inverse framing is just as valid: a patient receiving a standard monofocal IOL, with a routine pupil and a clear red reflex, is very unlikely to notice a difference in final vision whichever technique is used — which is exactly what the comparative trials, on balance, report.
Section 08 — The Agaaz Range
What sits in the tray
— regardless of the platform.
Agaaz Ophthalmics does not manufacture femtosecond laser platforms, but the intraocular case built around every cataract extraction — laser-pretreated or entirely manual — runs through the same anterior chamber protection, capsular visualization and infection-prophylaxis steps. GMP-manufactured, specified below by what they are, not how they are positioned.
If intraoperative pupil constriction complicates a case — a documented risk with either technique, discussed in our guide to intracameral carbachol for miosis control — the same closing protocol applies irrespective of platform. View the complete portfolio →
Section 09 — FAQ
Frequently asked questions
about FLACS.
FLACS uses an image-guided femtosecond laser, docked to the eye and steered by built-in OCT imaging, to perform three steps before conventional phacoemulsification begins: the corneal incisions, the anterior capsulotomy (the circular opening made in the lens capsule), and fragmentation or softening of the cataractous nucleus. The laser does not remove the cataract itself — a surgeon still completes the case with standard ultrasound phacoemulsification and lens implantation immediately afterward.
In manual phacoemulsification, the surgeon creates the capsulotomy freehand with a bent needle or forceps (a continuous curvilinear capsulorhexis), then chops and emulsifies the entire nucleus using ultrasound energy delivered directly by the phaco probe. In FLACS, the laser pre-cuts the capsulotomy to a computer-planned size and shape and pre-fragments the nucleus into segments before the phaco probe is ever introduced, so less ultrasound energy is needed to finish removing the lens.
Not consistently. A Cochrane systematic review and a large meta-analysis pooling comparative studies have both found low-to-moderate certainty evidence of little or no difference in final best-corrected visual acuity between FLACS and conventional manual phacoemulsification in general cataract populations. What FLACS reliably improves is the size, shape and centration consistency of the capsulotomy itself and the amount of ultrasound energy needed to finish the case — advantages that matter most when a centration-sensitive premium IOL is planned, not a guaranteed sharper outcome for every patient.
Overall complication rates are broadly similar between the two techniques in large comparative series, but the risk profile is different rather than one being simply lower. Some early FLACS series reported higher rates of anterior capsule tears or tags from the laser-cut capsulotomy edge, particularly during a surgeon's learning curve; larger, more recent series suggest this gap narrows with experience. FLACS also introduces its own limitations — a suction-based docking step that can occasionally cause an incomplete capsulotomy requiring manual completion, and difficulty imaging through a very dense cataract or a poor red reflex.
A femtosecond laser platform is a separate, expensive piece of capital equipment on top of a standard phaco machine, and most platforms also charge a per-case licensing or consumable fee. In most health systems, including Medicare in the US and most public and private insurance internationally, FLACS is billed as a refractive add-on rather than a medically necessary step, so the incremental cost is typically paid out of pocket by the patient rather than reimbursed.
Most cataract surgery worldwide, including the large majority of high-volume and outreach programs, is performed safely and effectively with manual or standard phacoemulsification and monofocal IOLs, where FLACS's main advantage — capsulotomy precision — has less practical impact. FLACS is most often selected when a diffractive multifocal or extended depth-of-focus IOL is planned, since those optics are more sensitive to capsulotomy size and centration, or when integrated astigmatism-correcting laser incisions are wanted alongside a toric IOL.
The docking and suction step needed to stabilize the eye under the laser has been associated in some series with transient intraoperative pupil constriction, which can complicate the remainder of the case if it is not anticipated. Loss of suction mid-treatment can leave an incomplete or irregular capsulotomy that the surgeon then has to complete manually. Laser imaging can also struggle to see through a very dense, brunescent cataract or a poor red reflex, occasionally forcing a conversion to a fully manual technique for that step.
References & Evidence Base
Peer-reviewed
citations.
Continue Reading
Related guides
from Beyond Vision.
Start writing here...
Femtosecond Laser-Assisted Cataract Surgery (FLACS) vs Manual Phaco: Precision, Price and the Evidence (2026 Guide)