What is the treatment and management approach for diffuse lamellar keratitis (DLK)?

Treatment and Management of Diffuse Lamellar Keratitis (DLK)

The treatment of diffuse lamellar keratitis should be guided by the severity of inflammation, with mild cases managed by increased frequency of topical corticosteroids and more severe cases requiring aggressive steroid therapy or surgical intervention with flap lifting and interface irrigation. 1

Diagnosis and Staging

DLK is a non-infectious inflammatory condition that occurs following LASIK surgery, characterized by:

• Inflammatory cell aggregation confined to the lamellar interface
• Fine granular reaction in the interface
• Typically occurs within the first few days after surgery
• Patient generally has no discomfort, with little or no conjunctival hyperemia or anterior chamber inflammation

Treatment Algorithm Based on DLK Severity

Stage 1-2 (Mild) DLK:

• Increase frequency of topical corticosteroid administration (prednisolone acetate 1%)
• Schedule closer follow-up (every 24-48 hours)
• These cases are generally self-limited with minimal visual consequences 1

Stage 3 (Moderate to Severe) DLK:

• More frequent and/or higher concentrations of topical corticosteroids
• Consider systemic corticosteroids (oral prednisone) if not responding adequately
• Studies show excellent outcomes with combined topical and oral steroids without the need for flap lifting 2

Stage 4 (Severe) DLK or Rapidly Progressing Cases:

• Lift the flap with irrigation of the interface
• Consider direct application of corticosteroids to the exposed stromal interface
• Monitor for stromal tissue loss and central corneal thinning 1, 3

Important Considerations

Differential Diagnosis

• Critical: Always differentiate between infectious and non-infectious causes before initiating treatment 4, 1
• Infectious keratitis presents with pain, redness, photophobia, focal infiltrates that often extend beyond the interface, and anterior chamber reaction
• If unresponsive to corticosteroids, consider microbial keratitis, interlamellar fluid due to increased IOP, intraocular inflammation, or endothelial decompensation 1

Monitoring and Complications

• Monitor for IOP elevation, especially in steroid responders
• Measure IOP peripheral to the flap edge for accurate readings
• Consider anti-glaucoma agents if IOP rises significantly 1
• In severe cases (stage 4), corneal thickness may decrease initially but can partially recover over 1-2 years 3

Long-term Management

• Vigilance during follow-up is essential, as DLK can recur idiopathically even a year after the initial episode 5
• For residual hyperopic shift due to stromal thinning, repeat femtosecond laser-assisted LASIK may be considered after stabilization (typically 1-2 years) 3

Prevention Strategies

• Careful examination of the external eye before surgery
• Strict cleaning and disinfection of the operative eye
• Proper disinfection of medical instruments
• Avoiding residual disinfectant
• Appropriate laser energy settings
• Gentle operative manipulation
• Avoiding repeated instrument insertion/removal
• Preventing oil and tear accumulation 4, 1

Treatment Pitfalls to Avoid

1. Delayed diagnosis: Early recognition and treatment are essential to prevent progression to more severe stages
2. Misdiagnosis as infectious keratitis: Unnecessary flap lifting and antibiotic treatment
3. Inadequate steroid dosing: Insufficient frequency or concentration may allow progression
4. Overreliance on surgical intervention: Research shows excellent outcomes with aggressive medical management alone in many cases 2
5. Premature discontinuation of treatment: Continue steroids until complete resolution to prevent recurrence
6. Failure to monitor for steroid complications: Regular IOP checks are essential

The incidence of DLK is relatively low (0.63-4% of LASIK cases), with severe DLK (stages 3-4) being even rarer (0.016-0.7%) 2, 3. With proper management, most cases resolve without permanent visual consequences.