A 49-year-old female patient was referred to our ophthalmologic clinic for an antibiotic-resistant left eye post-LASIK keratitis. The patient underwent the surgery 8 weeks earlier and presented first discomfort 12 days after. Prior to the referral, she had been treated initially as a conjunctivitis with topical tobramycin plus dexamethasone, and later, because of the degradation of her symptoms, as a bacterial keratitis, adding topical ciprofloxacin drops. At her arrival in our department, her treatment was tobramycin plus dexamethasone and hexamidin diisethionate drops, 3 times per day, artificial tears every 2 h and voriconazole 200 mg 2 times per day orally. She had no other ophthalmologic history and was only on thyroid replacement as medication.

She presented to our clinic with conjunctival injection, blurred vision, foreign body sensation, photophobia and tearing of her left eye. The visual acuity was of 5/10 without correction and 8/10 with pinhole. Anamnestically, the initial visual acuity was 10/10. Intraocular pressure (IOP) was normal and corneal sensitivity was diminished but preserved in both eyes. Anterior segment examination of the right eye was within normal limits, with a calm post-LASIK interface. On the left eye, she presented with palpebral swelling, diffuse conjunctival hyperemia with chemosis, a paracentral corneal ulcer of 1 mm with anterior stromal infiltrate and an inflammatory anterior chamber (Tyndall 1+) (Fig. 1). Fundus examination in pharmacological mydriasis was unremarkable for both eyes. Anterior segment optical coherence tomography (OCT) revealed a ruptured epithelial flap in her left eye, associated with an anterior stromal infiltrate. Suspecting post-LASIK infectious keratitis, we stopped all treatment except the artificial tears for 24 h, and then performed multiple scrape tests at the ulcer’s base, without lifting the flap, for pathogen identification. The patient was hospitalized and initially received treatment of tobramycin drops and moxifloxacin hourly, day and night, natamycin drops 6x/day and scopolamine bromhydrate 2x/day. After 48 h, the night drops were replaced with tobramycin ointment.

Slit lamp images of the left eye: white arrow pointing the mycobacterial keratitis’ ulcer. Upper right, the same image with fluorescein test revealing epithelium damage and the stromal impregnation

The symptoms diminished progressively in the next days but did not resolve entirely. The cornea’s ulcer healed until no stain was visible under fluoresceine, but a stromal opacity remained with haze. The initial scrape revealed the presence of Mycobacterium wolinskyi. All tests remained negative for a co-infection with a fungus or Acantomoeba, as indicated by the confocal microscopy images performed during the workup. With the slightly better corneal visibility we recognized at slit lamp examination the presence, under the LASIK flap, of a stromal foreign body in the form of a microscopic whitish round material at the initial ulcer’s base. This was confirmed with an anterior segment optical coherence tomography (OCT) revealing a shadow cone following its continuity (Fig. 2A).

After providing an explanation and obtaining the patient’s approval, we performed surgical interface cleaning. While not lifting the flap, a gripper was used through the button pinhole created to swab the stromal foreign body. Gentle cleaning of the surroundings was then performed. The post-operative control anterior segment OCT no longer showed the shadow cone and confirmed the thorough removal of the foreign body (Fig. 2B). The patient was then treated with moxifloxacin drops, initially hourly, and then every 2 h after one week. After 11 days, she presented again to our clinic with an increase in pain and photophobia. The visual acuity was 2/10. The anterior segment examination showed an anterior stromal opacity with a slight central fluoresceine staining but no infiltrates. There was no satellite lesion, and the anterior chamber was calm. Due to the deterioration, we suspected an uncontrolled infection with Mycobacterium wolinskyi and sought assistance from the division of infectious diseases at our university hospital of Geneva. According to their recommendation and the possibility of hospital’s pharmacy to fabricate the eyedrops, we introduced in addition to moxifloxacin: amikacin 5% and erythromycin 0,5%. Each drop was instilled every 1.5 h during the day, resulting in a rotation of one antibiotic each 30 min. Tobramycin ointment was initiated for night treatment, and oral treatment of doxycycline 100 mg 2 times daily plus moxifloxacin 400 mg once daily was also prescribed. A new conjunctival swab was performed which did not give any positive results. A few days later, the antibiogram from the first initial swab revealed resistance of the mycobacterium to tobramycin and clarithromycin which motivated the discontinuation of tobramycin ointment at night and the daily drops of erythromycin. The symptoms diminished progressively, and corneal examination improved in the following weeks. After 12 weeks of treatment, oral treatment of doxycycline and moxifloxacin was stopped, and topical treatment of moxifloxacin and amikacin was diminished from one drop every 2 h to 6 times daily each. All drops were discontinued after 24 weeks of total treatment. At this point, after 6 months of treatment, the patient was asymptomatic, visual acuity improved to 10/10 and corneal examination showed a remaining paracentral stromal scar with no fluoresceine staining (Fig. 3).

A) Anterior segment OCT revealing a foreign body highlighted by a shadow cone following his continuity. B) Anterior segment OCT post-surgical interface cleaning showing the disappearance of the shadow cone and the foreign body

Slit lamp image of the cornea with a healthy epithelium and a sub epithelial scare after termination of all treatment