What DLK is
Diffuse lamellar keratitis is a sterile inflammatory reaction in the interface between the LASIK flap and the underlying stroma. Under the microscope it looks like fine white sand scattered across the interface, which gave it the nickname 'sands of the Sahara.' It is not an infection; no organism is involved. Triggers include debris or bacterial toxins on instruments, meibomian gland secretions, epithelial defects, and sometimes no identifiable cause.
Incidence in modern practice is roughly 1 to 4 percent, with clusters sometimes traced to a specific sterilizer or instrument batch. Most cases are mild.
The four stages
| Stage | Appearance | Vision | Treatment |
|---|---|---|---|
| 1 | Fine cells at the flap edge | Normal | Frequent steroid drops |
| 2 | Cells spread across the center | Slight blur | Hourly steroids, sometimes oral |
| 3 | Dense clumps in the visual axis | Reduced | Flap lift and irrigation, steroids |
| 4 | Stromal melt and scarring | Permanently affected | Rare; damage control |
Progression from stage 1 to 3 can happen in 48 to 72 hours, which is why day one and day three or four checks are scheduled and why leaving the country the morning after surgery is unwise.
Symptoms
Often none at stage 1. Light sensitivity, a gritty feeling, and mild blur at stage 2. Noticeably reduced vision by stage 3. Because early DLK is silent, only the slit-lamp exam detects it.
How it is treated
Intensive topical steroids, typically every hour while awake for the first days, then a taper. Stage 3 and above are treated by lifting the flap in the clinic and irrigating the interface, followed by steroids. Pressure is monitored because heavy steroid use can raise it, and a pressure rise itself can produce interface fluid that mimics DLK (pressure-induced stromal keratitis), which requires the opposite treatment. This is exactly the kind of judgement call your surgeon needs to make in person in the first week.
DLK vs infection: why you cannot self-diagnose
Infectious keratitis under a flap is far rarer than DLK but much more dangerous, and its early appearance can overlap. The distinguishing features (location, pain, focal vs diffuse, timing) are a specialist's call. Any red, painful, or blurry eye in the first two weeks after LASIK needs same-day examination. See infection warning signs.
What this means for a travelling patient
- Stay at least four to five nights after LASIK, so the day-one and day-three or four checks happen with your surgeon.
- Do not stop steroid drops early or substitute a different product.
- Have a local ophthalmologist identified at home for the week-one visit if you fly before it.
- Ask your surgeon how many DLK cases the clinic has seen in the past year; a transparent answer beats "never."
For the whole recovery arc, read the first 48 hours.
Frequently asked questions
Is DLK an infection?
No. It is a sterile inflammatory reaction. Treatment is steroids, not antibiotics, though surgeons often use both while confirming the diagnosis.
Does DLK cause permanent damage?
Stages 1 and 2, which are the vast majority, resolve completely. Stage 3 and 4 can scar if not treated promptly.
Can DLK come back later?
Late DLK can be triggered by an epithelial defect or eye trauma years after surgery. It is treated the same way.
Want a surgeon who insists on proper follow-up?
We refer only to clinics that schedule day-one and day-three checks and give you a direct line for urgent questions.
WhatsApp Andy in MedellínRequest a quote