Pet Bird Bite Causes Rare LASIK Flap Displacement and Perforation 14 Years After Surgery

Fourteen years after undergoing laser eye surgery, a 40-year-old woman in Taiwan experienced a bizarre and severe ocular injury when her pet bird bit her left eye. The force of the bite did more than cause superficial damage; it punched a full-thickness hole through the corneal flap created during her LASIK procedure and displaced the flap from its original position. Ophthalmologists at Kaohsiung Medical University Chung-Ho Memorial Hospital have described this as the first documented case of a LASIK flap perforation and displacement directly caused by a bird bite. Their case study, published in the journal Medicine, highlights the long-term vulnerability of corneal flaps years after seemingly successful surgery.

A Week of Misdiagnosis and Worsening Symptoms

The patient had a history of unremarkable eye health following bilateral LASIK surgery 14 years prior to the incident. Following the bird bite, her left eye became increasingly blurry and irritated. She initially sought care at several local clinics, where physicians diagnosed a simple corneal abrasion—a scratch on the eye’s surface. Standard topical treatment was prescribed, but it failed to alleviate her symptoms.

By the time she was referred to the ophthalmology clinic at Kaohsiung Medical University, a week had passed, and her corrected visual acuity in the injured eye had deteriorated to 20/50, meaning she could only see at 20 feet what a person with normal vision could see from 50 feet. A detailed examination using slit-lamp biomicroscopy and anterior segment optical coherence tomography (OCT) revealed the true severity of the injury. The LASIK flap had shifted out of place, presenting irregular edges and showing signs of epithelial ingrowth—where surface cells begin migrating underneath the flap. Crucially, a full-thickness hole was discovered near the center of the cornea, through the flap itself.

This case underscores a known but dangerous diagnostic challenge: LASIK flap dislocations are frequently misdiagnosed as routine corneal abrasions in emergency settings, delaying the specialized care required to prevent permanent vision loss.

Persistent Vulnerability of the LASIK Flap

During LASIK, surgeons create a thin, hinged flap in the cornea, reshape the underlying tissue with a laser, and then reposition the flap. The flap heals without sutures, allowing for rapid recovery. However, the interface between the flap and the underlying corneal bed never fully regains the tensile strength of natural, healthy corneal tissue.

Research indicates that healing occurs predominantly at the peripheral edges of the flap, with minimal scarring toward the center. While this preservation of central clarity is essential for maintaining sharp vision, it leaves the central flap structurally weak and susceptible to being lifted or shifted by trauma.

Late-stage flap displacement is rare, but it is not unheard of. Medical literature documents various instances of flap dislocation occurring years after surgery, caused by eye rubbing, blunt force, fingernail scratches, or sports injuries. A 2024 review identified 21 cases of traumatic flap separation occurring at least six years post-LASIK, with some dating back up to 17 years. Animal-related injuries have also been reported, including a dog scratch that dislodged a flap 16 years post-surgery and a boa constrictor bite that perforated a flap just one year after the procedure. The U.S. Food and Drug Administration (FDA) continues to list flap migration as a potential long-term complication that may require secondary intervention.

Treatment and Recovery: Overcoming a Perforation

Upon her arrival at the specialized clinic, the surgical team successfully repositioned the corneal flap on the same day. To promote healing, the patient was treated with autologous serum eye drops, which are prepared from her own blood to provide concentrated growth factors.

The presence of a full-thickness perforation presented a unique challenge. Approximately four weeks after the repositioning surgery, epithelial cells began regrowing around and into the hole, posing a threat to her vision if left unchecked. To manage this, the ophthalmology team performed a series of Nd: YAG laser treatments at four, eight, and twelve weeks post-surgery. Utilizing low-energy pulses (roughly 20 to 24 pulses per session), the doctors precisely targeted and eliminated the invading cells around the perforation site.

The intervention was highly successful. The patient’s corrected vision improved significantly from 20/50 to 20/25, and long-term follow-up showed no recurrence of epithelial ingrowth.

Key Guidance for LASIK Patients

This rare case serves as a critical reminder for both patients and general practitioners: a displaced LASIK flap can easily be mistaken for a minor corneal scratch, especially by clinicians who are unaware of the patient’s surgical history. In this instance, the correct diagnosis was only made after the patient’s symptoms persisted despite standard care.

Furthermore, the mechanism of injury here was uniquely severe; unlike typical rubbing or blunt blows, the animal bite simultaneously displaced and perforated the flap, necessitating additional laser treatments to preserve vision.

Experts emphasize that while traumatic flap dislocation is highly uncommon, the corneal flap remains vulnerable to trauma indefinitely. LASIK patients who experience eye trauma—such as pokes, scratches, or animal bites—followed by symptoms of blurry vision, pain, or irritation should seek immediate evaluation from an eye specialist. It is vital to explicitly communicate the history of refractive surgery so that the clinician can directly examine the flap interface.

Summary of Key Facts

The Injury: A pet bird bite to the left eye displaced the patient’s LASIK flap and created a full-thickness perforation 14 years after her original surgery.

Initial Misdiagnosis: The injury was initially treated as a standard corneal abrasion at local clinics. Advanced imaging was required to reveal the flap displacement, perforation, and subsequent cell ingrowth.

Underlying Weakness: The LASIK flap interface does not regain normal corneal strength, as healing is limited to the flap’s outer edges, leaving the center vulnerable to trauma years later.

Treatment Protocol: The flap was surgically repositioned on the day of the injury. Three sessions of Nd: YAG laser therapy were successfully used to manage epithelial ingrowth around the perforation.

Visual Outcome: The patient’s vision recovered successfully from 20/50 to 20/25, with no long-term complications or recurrent cell growth.

Patient Advice: Anyone with a history of LASIK who suffers an eye injury accompanied by vision changes or pain should seek immediate ophthalmologic care and disclose their surgical history.

Source link