2015 RWAP winner There’s something in the water

Editor’s Note: Ophthalmology Times is pleased to announce Amy Patel, MD, of Gavin Herbert Eye Institute, UC Irvine Health, Irvine, CA, as the winner of its 2015 Resident Writer’s Award Program, sponsored by Allergan. Dr. Patel’s winning entry is featured here.

The Ophthalmology Times Resident Writer’s Award Program is a unique recognition opportunity designed to promote excellence in ocular surface disease education. It was created to acknowledge outstanding case identification and written presentation skills in ophthalmology residents.

This year’s second-place winner is Seanna Grob, MD, MAS, of Massachusetts Eye and Ear, Harvard Medical School, Boston, with her entry, “Management of drug-induced cicatricial conjunctivitis and dry eye.”

The third-place winner is Amelia Fong, MD, of Georgetown University School of Medicine, Washington, DC, with her entry, “Lifeless limbus.”

Look for their case study submissions in future issues of Ophthalmology Times.

By Amy Patel, MD, Special to Ophthalmology Times

A 41-year-old male with no significant past medical history initially presented to the eye clinic with a complaint of rapid onset of foreign body sensation, irritation, and eye redness of the right eye for 10 days prior to presentation.

He reported that he was traveling to Laos and Bangkok when the symptoms began. He was initially evaluated by an ophthalmologist in Bangkok and diagnosed with exacerbation of dry eye syndrome and started on artificial tears and topical steroids.

When the patient presented to the UC Irvine ophthalmology clinic, he noted that he was having worsening symptomatology despite the previous treatments.

Examination and ancillary studies

His visual acuity was 20/25 and 20/20 of the right and left eye, respectively. Initial slit lamp examination revealed no lid edema or erythema, a mild follicular reaction of the palpebral conjunctiva, and diffuse punctate epithelial keratitis with negative fluorescein staining.

There were no notable infiltrates or corneal thinning.

Given his lack of response to topical steroids, there was high suspicion for an infectious etiology. Corneal scrapings and conjunctival swabs were obtained and sent for analysis.

Diagnosis

Corneal cultures were positive for microsporidia. After thorough discussion of the diagnosis with the patient, an HIV test was performed and found to be negative.

Treatment

Our patient was started on topical moxifloxacin and oral albendazole and had significant improvement just several days after starting treatment.

Discussion

Microsporidia is a phylum encompassing more than 1,200 species of spore forming single-cell parasites. They are ubiquoutous and able to infect any other organism.

The transmission of microsporidia is not fully understood though it is commonly thought to spread via ingestion, inhalation, or direct contact with spores as in the case of ocular disease. They produce resistant spores that enter the host cell via a polar tubule, a unique feature of microsporidia.

After invading the host cell, microsporidia multiply. After multiplication and maturation of new spores, the host cell membrane is disrupted and the new spores can now enter other host cells.¹

Microsporidiosis infections are most common in HIV-infected patients with severe immunodeficiency and a CD4+ T-cell count below 100/μL. It classically manifests as a severe diarrhea leading to malabsorption, though any organ can be infected.

Microsporidial keratitis and keratoconjunctivitis was initially described among immunocompromised patients in the 1980s during the HIV epidemic. Though traditionally thought to be a disease of affecting primarily immunocompromised patients, in recent times, many case reports and series have described this disease process amongst immunocompetent patients as well.²

An outbreak of microsporidial keratoconjunctivitis among rugby team players was reported and linked to possible soil or water contamination.³

Several species of microsporidia have been isolated from environmental water samples.⁴

Others report a possible association between microsporidial keratoconjunctivitis and contaminated water and soil during the monsoon seasons in Singapore and other parts of southeast Asia.^5,6

Conclusions

The differential diagnosis of superficial punctate keratopathy is broad and includes dry eye syndrome among many other disease processes, including Thygeson’s keratitis, herpetic keratitis, and viral conjunctivitis.

An initial response to any treatment should be monitored carefully and a refractory response or an exacerbation of symptoms should warrant further investigation, including corneal and conjunctival cultures. Though microsporidial keratitis and keratoconjunctivitis are commonly thought primarily to affect immunocompromised patients, they should remain on the differential diagnoses for immunocompetent patients as well.

References

1. Centers for Disease Control and Prevention. http://www.cdc.gov/dpdx/microsporidiosis/

2. Chan CM, Theng JT, Li L, Tan DT. Microsporidial keratoconjunctivitis in healthy individuals: a case series. Ophthalmology. 2003;110:1420–5. DOIPubMed

3. Kwok AKH, Tong JMK, Tang BSF, Poon RWS, Li WWT, Yuen KY. Outbreak of microsporidial keratoconjunctivitis with rugby sport due to soil exposure. Eye. 2013;27:747-754. doi:10.1038/eye.2013.55.

4. S.E. Dowd, C.P. Gerba, I.L. Pepper. Confirmation of the human pathogenic microsporidia Enterocytozoon bieneusi, Encephalitozoon intestinalis and Vittaforma corneae in water. Appl Environ Microbiol, 64 (9) (1998), pp. 3332–3335.

5. Loh RS, Chan CM, Ti SE, Lim L, Chan KS, Tan DT. Emerging prevalence of microsporidial keratitis in Singapore: epidemiology, clinical features, and management. Ophthalmology. 2009;116:2348–2353.

6. Sengupta J, Saha S, Khetan A, Pal D, Gangopadhyay N, Banerjee D. Characteristics of microsporidial keratoconjunctivitis in an eastern Indian cohort: a case series. Indian J Pathol Microbiol. 2011;54:565–568.