LASIK, or Laser-Assisted In Situ Keratomileusis, corrects common refractive errors by reshaping the cornea. The procedure begins with the creation of a thin, hinged flap on the corneal surface, including the outermost layer (epithelium) and a portion of the layer beneath it. This flap is lifted to allow an excimer laser to precisely reshape the underlying corneal stroma. Once treatment is complete, the flap is smoothed back into position, where it adheres naturally without sutures, acting as a protective biological bandage.
Defining Complete Flap Loss
Complete flap loss is an infrequent but serious complication where the corneal tissue cap is entirely detached and cannot be salvaged or repositioned. This is distinct from a flap dislocation, where the tissue remains hinged but is displaced or wrinkled. The incidence of a lost flap is exceptionally rare, reported as occurring in fewer than 1 out of 1 million LASIK procedures.
A lost flap can occur during the surgical creation process due to issues with the microkeratome or femtosecond laser, or shortly after surgery. Immediate post-operative trauma, such as a severe blow to the eye or aggressive rubbing, is a common cause for dislodgement before the flap has fully adhered. When the tissue is completely lost, the underlying corneal stroma, which has been reshaped by the laser, is left exposed and unprotected.
Immediate Patient Experience and Clinical Signs
The immediate consequences of a lost flap require urgent medical attention. Patients typically experience severe, acute pain, which is worse than the mild discomfort expected after routine LASIK. This intense pain is often accompanied by excessive tearing and an extreme sensitivity to light, known as photophobia.
Vision is suddenly decreased, often described as severe blurriness or haze. Clinically, a physician will observe the exposed stromal bed, which lacks the protective epithelial layer and the flap itself. The unprotected stromal tissue is susceptible to infection and drying.
Acute Management and Treatment Protocols
The immediate management focuses on protecting the vulnerable, exposed stromal bed and promoting the regrowth of the corneal surface layer. The primary protocol involves placing a therapeutic soft contact lens, commonly called a bandage contact lens (BCL), which serves as a temporary physical shield. This lens acts as a substitute for the lost flap, covering the surgical site to reduce pain, prevent further damage, and create a smooth surface for the epithelium to regenerate.
Intensive topical medication is simultaneously initiated to prevent infection and manage inflammation. This typically includes broad-spectrum topical antibiotics to guard against bacterial invasion of the exposed tissue. Anti-inflammatory medications, such as steroid eye drops, are also prescribed to minimize inflammation and reduce the risk of excessive scarring (haze) during the healing process.
Epithelialization, the regrowth of the epithelium over the exposed stroma, is the most immediate goal of this acute phase. This healing process usually takes four days to a week and requires intensive monitoring by the ophthalmologist. The bandage contact lens is kept in place until the corneal surface is fully resurfaced by the new epithelial cells.
Long-Term Visual Prognosis and Recovery
Once the acute healing phase is complete and the surface layer has fully regrown, the eye begins a longer-term stabilization process. Vision generally improves significantly after epithelialization, but the loss of the flap results in a change to the cornea’s shape and structure. The resulting visual outcome is often similar to what is achieved with Photorefractive Keratectomy (PRK), a procedure that removes the surface layer before laser reshaping.
The long-term prognosis is often complicated by corneal haze, which is scar tissue forming on the surface of the stroma due to the trauma and healing process. This haze can interfere with the clarity of vision, and patients may not achieve the uncorrected visual acuity hoped for with standard LASIK. Corrective procedures, such as a second laser treatment like Phototherapeutic Keratectomy (PTK) or PRK, may be considered to smooth the corneal surface, reduce residual refractive error, or treat persistent haze.
These secondary enhancement procedures are typically delayed until the cornea has fully stabilized, which may take six to twelve months after the initial incident. Appropriate and timely management often leads to the recovery of functional vision, though patients may still require corrective eyewear for optimal clarity due to irregular healing or residual refractive changes. The final result can be variable depending on the severity of the initial injury and the subsequent corneal healing response.