Ocular Trauma FREE

A 35-year-old man presents to the emergency department (ED) with painful vision loss, tearing, and photophobia after being struck in the left eye by a plastic pole 3 days earlier. Immediately after the trauma he went to a primary care clinic, and corneal abrasion in the left eye was diagnosed. He received topical antibiotic ointment, but symptoms and signs persisted. His medical history is remarkable for uneventful laser-assisted in situ keratomileusis (LASIK) in both eyes 5 years ago. On examination, the best corrected visual acuities were 20/20 in the right eye and 20/200 in the left eye. Examination of the left eye revealed a superior corneal epithelial defect and foreign body material over the lesion (Figure 1). The remainder of the ocular examination, including fundoscopic examination, was unremarkable, and the right eye was unaffected.

A. Apply an eye patch, prescribe analgesics, and advise the patient to follow up at a primary care clinic

B. Apply topical antibiotics and refer the patient to an ophthalmologist within 24 hours

C. Contact an ophthalmologist for ED consultation

D. Remove the foreign body material and contact an ophthalmologist for ED consultation

Traumatic LASIK flap dislocation

C. Contact an ophthalmologist for ED consultation

The key clinical feature in this case is a history of trauma in a patient who had ocular surgery, especially LASIK, and the presence of corneal trauma. This combination of clinical findings and history indicates a suspected displaced or subluxated LASIK flap, which should be regarded as an emergency. Timely consultation with an ophthalmologist is indicated for further treatment to reposition the flap.

In the past 2 decades, LASIK has become the treatment of choice for many patients with refractive errors such as myopia, hyperopia, and astigmatism. Despite the high success rate, one possible complication after LASIK is traumatic injury to the flap. In the initial 24 hours after surgery, flap dislocation presumably occurs as a result of mechanical disruption.^1- 3 However, flap dislocations have decreased with improvement in techniques and instruments. Clare et al⁴ reported that only 9 of 41 845 patients had early flap dislocations within 48 hours of surgery. Although the incidence of flap dislocation is low, a patient with ocular trauma may still encounter such complication even up to 14 years postoperatively.⁵

LASIK flaps are thought to progressively fibrose, making the flap resistant to dislocation. However, Philipp et al⁶ showed that only a few collagen lamellae were visible crossing between the posterior residual stroma and the superficial flap. This was accompanied by minimally increased staining of dermatan sulfate proteoglycan within the stroma adjacent to the interface of microkeratome incision, accounting for weakened adhesion between flap and stroma in human corneas. Clinically, this leads to less central corneal scarring and a clear optical zone, but it also may permanently weaken the cornea, causing a disruption in the fibrous tissue at the edges of the flap, especially in the event of severe direct ocular trauma.

A displaced or subluxated flap should be regarded as an emergency, and a delay in diagnosis may lead to additional complications such as flap macrostriae, lamellar keratitis, and epithelial ingrowth, which may contribute to poor vision outcome. Before repositioning the dislocated flap, the ophthalmologist will evaluate the stromal surfaces of the flap and the corneal stroma should be scraped to remove any debris and epithelial cells. In the event of a lost flap, the epithelium is simply allowed to heal; however, this may result in significant irregular astigmatism.⁷

Corneal abrasions are common among patients with ocular trauma and often cause symptoms of tearing, pain, photophobia, and blurry vision. Since LASIK has become more popular worldwide—with approximately 700 000 procedures performed annually in the United States⁸—primary care or emergency physicians must avoid misdiagnoses of flap dislocations as simple corneal abrasions. A LASIK flap may be difficult to identify several years after the initial procedure; history should include ocular surgery history, including laser procedures, of any patient presenting with ocular trauma. Additionally, all patients who have received refractive surgery and experience significant ocular trauma should be advised to seek both general ophthalmological and further subspecialty care to prevent a delay in diagnosis and minimize potential complications.

In this patient, the flap dislocation occurred 60 months postoperatively (LASIK was performed in February 2007). The ophthalmologist surgically lifted the area of dislocated flap and scraped the stromal surfaces of the flap and bed to remove debris and epithelial cells. The flap was repositioned and smoothed with a spatula, and a bandage contact lens was placed. One month later, the bandage contact lens was removed, and the uncorrected visual acuity returned to 20/20 in the left eye. There was no evidence of epithelial defect, diffuse lamellar keratitis, or epithelial ingrowth (Figure 2).