Curvularia lunata Endophthalmitis

Introduction

Eye injuries during fishing are one of the most common causes of sports-related ocular trauma, second only to baseball, according to a database ¹ (U.S. Eye Injury Registry).

The trauma mechanism has great potential to cause both serious injury and blindness.

Ocular infection can result from penetrating trauma. Fungal infections are related to some types of traumas such as those with dirty or plant objects,^2,3 and they can be difficult to control.

This is a case report of ocular trauma during fishing, which involved corneal laceration and traumatic cataract surgery with subsequent ocular infection by Curvularia lunata.

Case Report

A 52-year-old man suffered a penetrating ocular trauma from a fish hook on the cornea of the left eye, and the fishhook transfixed the cornea and exited through the pars plana. The patient was promptly submitted to surgery to remove the artifact and repair the wound. An attempt was made to cut the hook off, but this was impossible due to the special type of steel of which it was made. Instead, the hook was flattened with a Kelly clamp and pulled out through the entry wound in the cornea. Intravitreal injections of vancomycin and amikacin were also administered. In 3 weeks, he was submitted to phacoemulsification with an in-the-bag intraocular lens implantation and achieved a visual acuity of 20/60.

In the following month, inflammatory signs developed, with vitreous opacities and decreased visual acuity (Fig. 1A).

OPEN IN VIEWER

FIG. 1.

(A) Before intravitreal injection of the antifungal. Note the fluffy lesions above and vitreal opacity. (B) After 2 weeks of treatment, with improvement of inflammation. (C) After antifungal treatment with good observation of the posterior pole. (D) Final state of the corneal scar.

As endophthalmitis was suspected, a pars plana vitrectomy (PPV) was performed, and intraocular antibiotic injections were again given. Culture samples were also collected and found to be positive for Staphylococcus epidermidis. With no clear signs of improvement (Fig. 1B), another PPV was carried out with intraocular lens explantation and capsular bag removal with administration of antibiotics.

Sample culture revealed positive fungal growth, and since there was only mild inflammation, the patient received only oral antifungal treatment, with itraconazole, 200 mg/day, until 2 weeks later when the fungus C. lunata was identified in both the lens and the capsule sample.

The patient then received 3 daily intraocular voriconazole (Vfend; Pfizer, Germany) injections of 100 μg, repeated the subsequent week, and continued to use oral itraconazole for 2 months, with a rapid decrease in signs of infection and improved visual acuity.

Vitreous opacities improved and the fluffy vitreal lesions almost disappeared (Fig. 1C). The best corrected visual acuity improved to 20/30, and no inflammation was found (Fig. 1D).

Discussion

This case has 2 important special features. The hook extraction was performed in a special way. It was believed that the best thing to do was to cut off the hook, but this was impossible due to the special steel of which the hook was made and the lack of a special tool.^4,5 The extraction, as mentioned above, was performed by flattening the hook with a Kelly clamp and pulling it out through the entry wound.

The other interesting observation was the development of the infection. Because no antifungal drugs were administered in the initial treatment, due to their retinal toxicity, ⁶ infection developed. Initially, a bacterium was isolated that differed from the one found as the contamination of the sample. This isolated bacterium, S. epidermidis, was sensitive to the intravitreous drugs already used. It was difficult to prove the actual agent, and this was only possible with lens and capsular bag explantation and culture analysis. Although the Gram staining had identified fungal presence, the culture report took over 2 weeks to reveal the specific C. lunata growth.

We preferred not to use amphotericin, because of retinal toxicity. ⁶ After Curvularia was isolated in the culture sample, we realized the need to use another class of drugs, with a broad-spectrum profile. ⁷

C. lunata is a dematiaceous fungus rarely responsible for human eye infections, and amphotericin shows a very weak action against this agent.^8,9 Ocular damage is more common in the form of keratitis, this being the fourth most common cause, after Candida, Fusarium, and Aspergillus.^2,3 There are other species besides C. lunata such as C. senegalensis, C. pallescens, and C. prasadii. The majority of cases involve wound infection. In 1,352 cases of keratitis, 16.1% were related to dematiaceous fungi, ³ and Curvularia species were the most common, at 2.8%. ³

Another review of 42 patients with Curvularia's keratitis showed that the majority began during summertime, during hot and humid weather, while the spores were being released. ² Trauma occurred in every case, and a large number was due to plants or dirt. They presented with superficial infiltration with slow progression, ¹⁰ and had a slower course with little inflammation compared with other fungal infections. ²

Topical use of natamycin 5%^2,3 led to clinical resolution for the large majority of the patients. Curvularia responded well to all agents ² and oral administration can cure corneal infection even without the use of topical medication. Voriconazole performed well in vitro and can be used. ² The treatment averaged 40 days and had good final outcome in 78% of cases.

Due to the gravity of intraocular damage, by the presentation of endophtalmitis in such cases, drugs such as second-generation triazoles should be used; they act on ergosterol, inhibiting cytochrome P450 demethylase, and produce less interference with human cells, unlike former drugs.

Voriconazole is a new triazole antifungal agent derived from fluconazole, which acts against several types of fungi, including fluconazole-resistant strains. The drug exists in both intravenous and oral forms, with good bioavailability and therapeutic levels in the aqueous and vitreous.^8,11

Intravitreal injections caused no electroretinographic or histopathologic abnormalities in animal models ¹² and 100 μg/0.1 mL administration with PPV was an effective therapy for Aspergillus endophthalmitis. ¹³

Intravitreal injection achieves greater ocular levels, but it is more invasive, incurring a risk of further complications and new infections. Another factor to be considered is the clearance of the drug, which normally occurs within about 24 h; the systemic use of antifungals, in spite of achieving lower concentrations, maintain a constant intraocular level.

It was decided to use 3 consecutive intravitreous voriconazole injections due to the increased clearance after previous PPV, in an attempt to achieve a good intraocular concentration.

Considering this and the cost of voriconazole, we opted to maintain the oral medication only after the initial intravitreal use.

As far as we know, there are only a few cases published in the literature about C. lunata endophthalmitis. In one case, capsular plaque was described as one of the signs of an infectious agent for differential diagnosis. ¹⁴

Besides this case, there is another reported case of endophtalmitis related to an infection by this fungus, followed by keratitis ⁹ and another one following cataract extraction. ¹⁵

In this case, C. lunata was identified for the first time as the infectious agent after a fishing-related trauma. Good visual acuity was restored after intravitreal and systemic antifungal treatment.

Traumas related to fishing are not rare and are potential threats to vision. In dealing with penetrating traumas, ophthalmologists should always be aware of the possibility of fungal infection.

Ocular trauma related to fishing can be followed by fungal infection both in the cornea and vitreous. The type of agent that could be isolated in the cultures cannot be foreseen. The isolation of the agent for in vitro antifungal sensitivity tests is recommended, and should be carried out mainly for cases in which the outcome of the initial treatment does not show clinical improvement.