During LASIK, the microkeratome stops before the flap is complete. What should the surgeon do?

Not apply the laser and reschedule With an incomplete or irregular flap the laser should not be applied, because ablating under a defective flap leads to irregular astigmatism.

Complete the ablation on the partial bed

Convert immediately to a free cap

Apply the laser after suturing the flap

Which intraoperative LASIK flap problem is specific to femtosecond lasers and blocks tracking?

Opaque bubble layer An opaque bubble layer can form with femtosecond lasers and blocks eye tracking during the ablation.

How do LASIK flap striae appear at the slit lamp with fluorescein?

As negative staining lines A narrow beam, retroillumination and fluorescein show striae as negative staining lines across the flap.

As bright pooling at the flap edge

As a dendritic staining pattern

When is the best time to intervene for LASIK flap striae?

Within the first days after surgery Striae are best treated within the first days, before the epithelium heals over the fold lines; the flap is lifted, the bed hydrated and the flap stretched perpendicular to the fold.

After three months, once stable

Only after topography confirms ectasia

Which treatment is used for diffuse lamellar keratitis after LASIK?

Frequent topical steroids Diffuse lamellar keratitis is a sterile interface inflammation that responds to frequent topical steroids, with interface irrigation in severe cases.

Intensive fortified antibiotics alone

Topical antifungals for six weeks

Interface infection appearing several days after LASIK, rather than early, suggests which organisms?

Atypical mycobacteria or fungi Infection tends to appear later than inflammation, with focal infiltrates and pain; delayed onset after several days suggests atypical mycobacteria or fungi.

How is peripheral, stable epithelial ingrowth after LASIK usually managed?

Observation, removing it only if it threatens vision Peripheral, stable ingrowth is observed; it is removed if it threatens vision or melts the flap.

Immediate flap lift and scraping

Topical mitomycin C to the edge

Why can a LASIK flap dislocate after blunt trauma years after surgery?

The flap stays only weakly attached for life Flaps remain weakly attached to the stroma for life, so trauma such as contact sports or airbag deployment can dislocate them years later.

The stromal bed regrows epithelium

The interface fills with fluid over time

After a LASIK buttonhole or free cap, which later refractive option is considered once the tissue has healed?

Surface ablation after months of healing The tissue is replaced carefully and left to heal for months, after which surface ablation can be considered.

A second microkeratome flap at once

Intracorneal ring segment implantation

Deep anterior lamellar keratoplasty

Which patients are more prone to an intraoperative epithelial defect during LASIK flap creation?

Older patients and those with basement membrane disease Epithelial defects during flap creation are more common in older patients and in those with epithelial basement membrane disease.

Young myopes with thick corneas

Patients with steep keratometry only

Patients with previous cataract surgery

LASIK Flap Complications: Recognition and Management

LASIK flap complications arise during creation of the corneal flap, in the early postoperative period, or years later after trauma.

Most are uncommon with modern microkeratomes and femtosecond lasers, but they can cause lasting visual disturbance if clinicians miss or mishandle them.

Knowing the pattern of each complication helps the surgeon to react in the right way.

Intraoperative LASIK Flap Complications

Incomplete flap: the microkeratome stops before the flap is complete, and the laser should not be applied
Thin flap and buttonhole: a hole in the flap, usually over a steep cornea, and the ablation should also be postponed
Free cap: the flap is fully detached, and it must be saved and repositioned with correct orientation
Irregular or decentered flap: from poor suction or a poor cornea
Epithelial defect: more common in older patients and in those with basement membrane disease (see map-dot-fingerprint dystrophy)
Suction loss: interrupts the cut, and the procedure should be stopped
Opaque bubble layer with femtosecond lasers, which blocks tracking

The surgeon should stop and reschedule the ablation when the flap is irregular, since going ahead with a defective flap leads to irregular astigmatism.

LASIK Flap Complications: Early Postoperative Problems

Flap striae or folds: wrinkles in Bowman layer that can cause irregular astigmatism and ghosting
Flap slippage or displacement: from rubbing or trauma in the first hours and days
Diffuse lamellar keratitis: a sterile inflammation in the interface (see diffuse lamellar keratitis)
Infectious keratitis: including bacterial and atypical mycobacterial infection (see nontuberculous mycobacterial keratitis)
Epithelial ingrowth: cells growing beneath the flap edge (see epithelial ingrowth)
Interface debris and pressure-induced stromal keratitis

Test your knowledge 10 questions from this article

Late Problems

Flaps remain only weakly attached to the stroma for life, and traumatic dislocation can occur years after surgery.

Late-onset striae, epithelial ingrowth, and ectasia are also other long-term problems (see post-LASIK ectasia).

Advise patients that blunt trauma to the eye, even years later, can displace the flap, and that sports require eye protection.

Evaluation for LASIK Flap Complications

Examine the flap at the slit lamp with a narrow beam, using retroillumination and fluorescein to show striae as negative staining lines.

In addition, check the interface for cells, debris, or epithelium, and examine the edges for gaps.

Topography and refraction demonstrate irregular astigmatism, and OCT can show flap thickness and interface changes (see anterior segment OCT).

Management for LASIK Flap Complications

Striae: lift the flap, rehydrate or stretch it, smooth it with a spatula, and reposition it, and in persistent cases add sutures
Displaced flap: reposition it urgently, clean the interface, and scrape epithelium from the bed if it has grown in
Buttonhole or free cap: replace the tissue carefully, allow healing for months, and consider surface ablation later
Diffuse lamellar keratitis: frequent topical steroids and, in severe cases, interface irrigation
Infection: culture, lift the flap, irrigate, and start intensive antibiotics
Epithelial ingrowth: observe if peripheral and stable, and remove if it threatens vision or melts the flap

The decision on timing is important, because early intervention for striae and dislocation leads to better results.

LASIK Flap Complications: Recognition and Management

Prevention

Careful patient selection, accurate suction, a good surgical technique, and a clean environment reduce complication rates.

Patients should also receive clear postoperative instructions about not rubbing the eyes, about eye shields, and about reporting symptoms.

Managing Specific Problems in More Detail

For flap striae, the best time to intervene is within the first days, when the epithelium has not healed over the fold lines.

Lift the flap under a microscope, hydrate the bed, and stretch the flap in the direction perpendicular to the fold with a moist sponge or spatula, then allow it to adhere.

Some persistent striae require suturing, or removal of the epithelium over the fold to flatten it.

A bandage lens may help.

For a free cap, mark the epithelial side with a stain before removal, keep the tissue moist on a dry surface in a chamber, and replace it with the epithelium up after the ablation or after postponing it.

Interface Inflammation Versus Infection

Early after LASIK, diffuse lamellar keratitis appears within a day or two as sand-like granules in the interface.

It responds to topical steroids.

Infection tends to appear later, with focal infiltrates, pain, and progressive worsening, and delayed onset after several days suggests atypical mycobacteria or fungi.

When in doubt, lift the flap, culture the interface, and treat for infection while the results are pending.

Advice for Patients

Tell patients to avoid rubbing the eyes, to wear the shield at night for the recommended time, and to avoid swimming and dusty environments in the first weeks.

Explain that flap displacement can occur from trauma, and that any sudden blur, pain, or foreign body sensation requires urgent review.

Doctors recognize contact sports and airbag deployments as causes of late flap dislocation.

A note in the record helps future clinicians to be aware of the history of LASIK.

References

Melki SA, Azar DT. LASIK complications: etiology, management, and prevention. Surv Ophthalmol. 2001;46:95-116.
Stulting RD, Carr JD, Thompson KP, et al. Complications of laser in situ keratomileusis for the correction of myopia. Ophthalmology. 1999;106:13-20.
Ambrósio R Jr, Wilson S. LASIK vs LASEK vs PRK: advantages and indications. Semin Ophthalmol. 2003;18:2-10.
American Academy of Ophthalmology. Basic and Clinical Science Course, Section 13: Refractive Surgery. AAO; current edition.

Test yourself

A few questions straight from this article.

1 / 10 0 correct

During LASIK, the microkeratome stops before the flap is complete. What should the surgeon do?
With an incomplete or irregular flap the laser should not be applied, because ablating under a defective flap leads to irregular astigmatism.
Which intraoperative LASIK flap problem is specific to femtosecond lasers and blocks tracking?
An opaque bubble layer can form with femtosecond lasers and blocks eye tracking during the ablation.
How do LASIK flap striae appear at the slit lamp with fluorescein?
A narrow beam, retroillumination and fluorescein show striae as negative staining lines across the flap.
When is the best time to intervene for LASIK flap striae?
Striae are best treated within the first days, before the epithelium heals over the fold lines; the flap is lifted, the bed hydrated and the flap stretched perpendicular to the fold.
Which treatment is used for diffuse lamellar keratitis after LASIK?
Diffuse lamellar keratitis is a sterile interface inflammation that responds to frequent topical steroids, with interface irrigation in severe cases.
Interface infection appearing several days after LASIK, rather than early, suggests which organisms?
Infection tends to appear later than inflammation, with focal infiltrates and pain; delayed onset after several days suggests atypical mycobacteria or fungi.
How is peripheral, stable epithelial ingrowth after LASIK usually managed?
Peripheral, stable ingrowth is observed; it is removed if it threatens vision or melts the flap.
Why can a LASIK flap dislocate after blunt trauma years after surgery?
Flaps remain weakly attached to the stroma for life, so trauma such as contact sports or airbag deployment can dislocate them years later.
After a LASIK buttonhole or free cap, which later refractive option is considered once the tissue has healed?
The tissue is replaced carefully and left to heal for months, after which surface ablation can be considered.
Which patients are more prone to an intraoperative epithelial defect during LASIK flap creation?
Epithelial defects during flap creation are more common in older patients and in those with epithelial basement membrane disease.

Ahmed Ophthalmologist

Writes and reviews the clinical articles on Educate. Every post is checked against peer-reviewed sources before it goes live.