Fungal keratitis after laser in situ keratomileusis (LASIK) is rare, and there have been only isolated case reports in the literature.1–5 The organisms vary and include Aspergillus, Acremonium, Curvularia, Fusarium, and Scedosporium. Fungal keratitis usually follows trauma, but most cases following LASIK have occurred with no history of trauma.2–5 To our knowledge, no report has traced the source of causative fungal organisms. We report an unusual case of infectious keratitis caused by a Curvularia species that could be directly traced to a fungal skin infection of the patient's pet cat.
A 50-year-old white man had bilateral LASIK for myopia at an outside facility 2 weeks before presentation to our institution. The preoperative refraction and visual acuity were −4.75 +0.25 × 80, 20/25, in the right eye and −7.75 +1.25 × 75, 20/20, in the left eye.
The procedures were uneventful except that the suction ring had to be reapplied because it slipped off center in both eyes before the flap was made. The surgeon noted no evidence of a flap complication such as an epithelial slide, defect, or buttonhole. The Chiron Hansatome® microkeratome (Bausch & Lomb Surgical) was used to make the flaps, and the ablation was uneventful. Postoperatively, the patient was started on ofloxacin (Ocuflox®) and fluorometholone (FML®) eyedrops 4 times a day. On the evening of the procedure, the patient reported severe pain in the left eye and was seen by the surgeon, but no problem was detected. The patient said that “the numbing drops” relieved the pain and he was comfortable the rest of the night. The next day, the uncorrected visual acuity (UCVA) in the left eye was 20/25−2 and the patient reported good vision. The best spectacle-corrected visual acuity was not recorded.
Five days after discontinuing the week-long course of steroid and antibiotic eyedrops, the patient noticed that his left eye ached and the vision was blurred. The symptoms worsened over the next few days, at which time he saw his ophthalmologist and was found to have a “dendritic” lesion on the left cornea. The patient was started on hourly trifluorothymidine (Viroptic®) and ciprofloxacin (Ciloxan®) eyedrops, but the symptoms worsened over the next 24 hours with the development of an infiltrate. He was then referred to our cornea and external disease service.
Upon presentation, the patient denied any medical illness or ocular trauma. The UCVA was 20/20−2 in the right eye and 20/60−1 in the left eye with no improvement with pinhole. Pupillary reaction, intraocular pressure, and motility were normal. Slitlamp examination revealed a well-healed flap with quiet anterior and posterior chambers in the right eye. The left eye (Figure 1) had moderate conjunctival injection. There was a white paracentral infiltrate measuring 2.5 mm × 2.0 mm involving almost full corneal thickness with feathery edges and an overlying epithelial defect. There were stellate projections from the infiltrate at the level of the flap interface. The anterior segment showed a moderate inflammatory reaction with a few large keratic precipitates under the infiltrate. The posterior segment was quiet.
Bacterial and fungal cultures as well as smears were obtained. The smears revealed multiple filamentous fungi, and the patient was started on natamycin 5% every hour, fortified cefazolin 4 times a day, and scopolamine 0.25% 3 times a day. The infiltrate responded well to the treatment with a decrease in the stellate projections. However, the patient developed severe diffuse inflammation and edema of the flap with a decrease in visual acuity to 2/200. This inflammation appeared to be localized to the flap interface, representing a secondary diffuse lamellar keratitis in response to the infection (Figure 2).
The cultures grew Curvularia sensitive to natamycin. When the patient was told about the results, he mentioned that 3 pet cats and 1 pet dog were undergoing treatment for a recalcitrant fungal skin infection. The pets' infections recurred whenever antifungal medications were discontinued. Cultures were obtained from the skin of the cat that had lesions, and these grew Curvularia. Cultures were also obtained from various household surfaces as well as from the patient's contralateral eye and his wife's eyes. These were negative for Curvularia.
Twelve days after presentation, the patient developed a pinpoint perforation in the center of the infiltrate with a flat anterior chamber. This was treated with tissue adhesive and a bandage contact lens. The cornea cleared over the next few days, and the UCVA improved to 20/60− with disappearance of the interface inflammation.
At the last examination, 2 months after presentation, the patient's infiltrate had completely healed and the UCVA was stable at 20/60. There was a depressed scar in the flap in the region of the original infiltrate with focal scarring. The area of perforation remained thin with overlying epithelial hyperplasia.
Infectious keratitis, especially fungal, following LASIK is extremely rare. In this case, the patient may have had an abrasion following the LASIK procedure given the history of pain relieved by a topical anesthetic agent. His cornea may then have been inoculated by the Curvularia from direct contact with an infected cat as the patient stated that the cats slept on or close to his head on the night of the surgery. It is also possible that he became infected by airborne fungal elements or spores as Curvularia is present in the environment and is thought to be an important allergen in patients with allergic rhinitis. The patient also had hundreds of household plants and no air conditioning. However, cultures obtained from various household surfaces were negative for Curvularia, although other fungi were cultured. Host colonization is also unlikely given that cultures from the patient's contralateral conjunctival fornix and his wife's conjunctival fornices were negative for Curvularia.
Although the infection appeared to be responding to the topical treatment, the cornea perforated even though no steroids were used. We believe this is because the infection started in the interface, closer to Descemet's membrane than the usual infiltrate that begins superficially. Review of the literature reveals a higher risk for corneal perforation (5 times greater) in fungal keratitis than in bacterial keratitis.6–8 As topical antifungal medications have poor penetration, the more superficial infection may have responded while the deeper infection continued to progress, causing a perforation.
This case demonstrates that an increased risk for fungal keratitis following LASIK may include iatrogenic (eg, corneal abrasion) as well as environmental (eg, infected pets) factors. It also emphasizes the importance of patient education about postoperative ocular hygiene and care.
1. Read RW, Chuck RSH, Rao NA, Smith RE. Traumatic Acremonium atrogriseum keratitis following laser-assisted in situ keratomileusis. Arch Ophthalmol 2000; 118:418-421
2. Sridhar MS, Garg P, Bansal AK, Sharma S. Fungal keratitis after laser in situ keratomileusis. J Cataract Refract Surg 2000; 26:613-615
3. Sridhar MS, Garg P, Bansal AK, Gopinathan U. Aspergillus flavus keratitis after laser in situ keratomileusis. Am J Ophthalmol 2000; 129:802-804
4. Chung MS, Goldstein MH, Driebe WT Jr, Schwartz B. Fungal keratitis after laser in situ keratomileusis: a case report. Cornea 2000; 19:236-237
5. Kuo IC, Margolis TP, Cevallos V, Hwang DG. Aspergillus fumigatus keratitis after laser in situ keratomileusis. Cornea 2001; 20:342-344
6. Wong T-Y, Ng T-P, Fong K-S, Tan DTH. Risk factors and clinical outcomes between fungal and bacterial keratitis: a comparative study. CLAO 1997; 23:275-281
7. Jones DB, Sexton R, Rebell G. Mycotic keratitis in South Florida: a review of thirty-nine cases. Trans Ophthalmol Soc UK 1969; 89:781-797
8. Rosa RH Jr, Miller D, Alfonso EC. The changing spectrum of fungal keratitis in south Florida. Ophthalmology 1994; 101:1005-1013