Acanthamoeba infection difficult to confirm

RYAN BUCSI, OMIC Senior Litigation Analyst

Allegation

Failure to diagnose and treat acanthamoeba infection resulting in enucleation.

Disposition

Settled on behalf of two OMIC-insured physicians and an insured entity for $70,000 each.

Summary

An OMIC-insured general ophthalmologist initially examined the patient for dendrite-appearing lesions on the left eye. The patient had been on Acyclovir and Viroptic, antiviral medications, for two weeks. Upon examination, the insured diagnosed antiviral toxicity with underlying stromal involvement. Lotemax, a steroid eye drop, was prescribed. The insured planned to taper the Viroptic. Upon examination, two days later, the lesion was unchanged. Five days later, the insured noted a raised area of the epithelium that had a dendritic pattern. The area did not stain, so he concluded that this was not an active dendrite. Three days later, the insured noted that the epithelium had broken down and that part of the epithelial surface was missing. The epithelial defect was 6 mm by 2.5 mm with a 1% hypopyon. The ophthalmologist obtained cultures and increased the frequency of the Lotemax and decreased the frequency of the Viroptic. Cultures revealed no white blood cells or organisms on the gram stain, no growth on the general culture, and no virus in the tissue biopsy. There were inadequate cells for antigen detection in the adenovirus and herpes simplex stains. Due to the progression of the patient’s condition, he referred her to an OMIC-insured corneal specialist and asked her to inform the specialist that he suspected acanthamoeba. The corneal specialist’s initial impression was a neurotrophic-appearing cornea with a 4 mm defect at the center of the cornea and some small peripheral defects, and Viroptic toxicity. Acyclovir was increased and Viroptic was discontinued. The patient was started on a low dose steroid and 50% serum tears. After the visit with the corneal specialist, the patient self-referred to a non-OMIC insured ophthalmologist, who diagnosed neurotrophic keratoconjunctivitis. The cultures he obtained were all negative. The patient returned to the insured corneal specialist, who noted a hypopyon and an 8 mm corneal defect. The insured referred the patient to a local university. Despite negative cultures, the ophthalmologist there decided to treat the patient empirically for acanthamoeba with Baquil and Brolene. He eventually performed a penetrating keratoplasty but the graft failed and the patient ended up with no light perception vision OS. The left eye ultimately became painful and the patient chose to have an enucleation.

Analysis

Plaintiff’s expert testified at deposition that he believed to a reasonable degree of medical certainty that the patient had acanthamoeba from the start. He criticized the OMIC insureds for not placing the patient on a “drug holiday” to determine the cause of her eye inflammation. He also criticized the culture method, arguing that the ophthalmologist needed to perform a scraping and plating of the specimen on media that was more likely to grow acanthamoeba. The expert testified that both the general ophthalmologist and corneal specialist should have seen the patient more frequently until her condition improved. Following the enucleation, OMIC’s defense counsel retained a pathologist to examine the specimen; however, they did not proceed with the examination out of concern that the review would confirm the presence of acanthamoeba. Plaintiff counsel did move forward with a pathology expert, and just as defense counsel feared, the pathologist identified acanthamoeba on the slides. The defense’s own pathology expert then confirmed the presence of acanthamoeba. Prior to this development, OMIC spent $500,000 defending the insureds due to a strong belief that the case was defensible. This problematic development changed the defense team’s opinion and a settlement of $210,000 was negotiated on behalf of the general ophthalmologist and his group and the corneal specialist.

Risk management principles

This case illustrates how challenging it can be to correctly diagnose certain types of corneal infections. Cultures were obtained by each physician and all were negative. It was only after an enucleation that a pathologist determined the presence of acanthamoeba. The general ophthalmologist could not make a definitive diagnosis yet waited two weeks to refer the patient to a corneal specialist. The corneal specialist also struggled to pinpoint the cause of the patient’s condition but did not refer the patient to a specialist at the local university for two months. When a diagnosis cannot be reached and a patient continues to deteriorate, it is prudent to promptly refer the patient on to a specialist for further examination and testing. The plaintiff argued that if the referrals had been expedited, treatment could have started earlier and the eye might have been saved.