A 38-year-old woman underwent uneventful bilateral LASIK eye surgery with a superior hinge in August of 2005. The preoperative refraction was -6.25 Ds -0.75 Dc Ax 15 in the right eye and -3.00 Ds -0.75 Dc Ax 10 in the left eye. The procedure was performed using the Moria M2 microkeratome with bilateral 120 µm LASIK flaps and NIDEK EC-5000 excimer laser. The ablation depth was 56.00 µm in the right eye and 53.20 µm in the left eye. The postoperative uncorrected visual acuity (UCVA) was 20 / 20 in both of the patient's eyes. The patient did not report any systemic disease, allergy or medication history. Four years after initial surgery, the right eye of the patient was scratched by a tree sprig during recreational mountain climbing. She did not wear protective goggles or glasses during mountain climbing. One morning after the accident, the patient visited the emergency room due to severe ocular pain and photophobia, as well as decreased visual acuity.
On examination, the UCVA was 0.125 in the right eye of the patient. Slit-lamp microscopy showed diffusely distributed opacities with crystalline materials in the LASIK interface (). Fluorescein staining revealed a 3 × 1 mm sized corneal epithelial defect and surrounding linear infiltration without any displacement of the LASIK flap. No anterior chamber reactions were noted. Considering the patient's history of trauma from organic plant matter, the epithelial defect with infiltration was suspected of flap infection. Accordingly, smears and cultures were taken around the base and margin of the corneal epithelial defect. No microorganisms were identified with Gram or Giemsa stains and potassium hydroxide wet mounts. Medical treatments with broad-spectrum antibiotics, including moxifloxacin 0.5% (Vigamox; Alcon Laboratories, Fort Worth, TX, USA) and tobramycin 0.3% (Tobra; Daewoong, Seoul, Korea) were applied every hour with systemic intravenous third generation cephalosporin.
Fig. 1 Slit-lamp photograph of the patient before flap lifting and irrigation. Upper photographs (A) (before pupillary dilatation) and (B) (after papillary dilatation) show diffusely distributed crystalline materials with stromal infiltration at the laser in (more ...)
On hospital day two, the patient developed diffuse cornea edema. The UCVA in her right eye decreased to 0.02. The corneal epithelial defect was completely healed with stationary diffuse stromal opacities at the LASIK interface. The amount of crystalline materials had not increased. The next morning, the amount of crystalline materials was stationary, but the shape and the distribution of the materials had changed. The materials seemed to have rotated in a counterclockwise direction (). Furthermore, culture results revealed no growth of microorganisms after 72 hours. Accordingly, these findings confirmed that the crystalline materials were foreign bodies rather than a sequela of infectious keratitis.
Surgery to remove the foreign bodies was performed under topical anesthesia. After placement of alignment markings, the lamellar flap was lifted with a spatula without difficulty. The stromal bed and lamellar flap were explored. Multiple crystalline foreign bodies were found and grasped from the stromal bed and undersurface of the lamellar flap with fine corneal forceps. Re-cultures were taken from the stromal bed and foreign bodies using sheep blood agar, chocolate agar, Sabouraud dextrose agar, and thioglycollate broth. After sufficient irrigation with balanced salt solution, no crystalline materials were found on the stromal bed or beneath the flap. The corneal alignment markings were checked to assure correct positioning of the flap. To prevent flap wrinkles, the corneal flap was wiped with a moistened microsurgical sponge and given three minutes to ensure flap adhesion.
On the first postoperative day, the patient's UCVA was 0.03 and she reported decreased corneal irritation. On examination, her cornea showed slightly decreased interface opacities with cleared crystalline debris (). On postoperative day three, culture results from specimens taken in the operating room revealed a species of Staphylococcus epidermidis that was sensitive to ciprofloxacin. Accordingly, treatments of topical tobramycin ceased, moxifloxacin continued, and topical prednisolone acetate 1% (Pred Forte; Allergan, Irvine, CA, USA) was added four times a day. One month after surgery, the patient's UCVA was 0.8 with cleared LASIK interface. No signs of epithelial ingrowth or flap striae were noted.
Slit-lamp photograph of the patient after flap lifting and irrigation. In (A) and (B), crystalline materials at the laser in situ keratomileusis interface were cleared and conjunctival injection decreased on the first postoperative day.