Indian Journal of Medical Microbiology Medknow Publications on behalf of Indian Association of Medical Microbiology ISSN: 0255-0857 EISSN: 1998-3646 Vol. 28, Num. 2, 2010, pp. 182-182

Indian Journal of Medical Microbiology, Vol. 28, No. 2, April-June, 2010, pp. 182

Correspondence

Bilateral mycotic keratitis in a case of hyperthyroidism-induced exophthalmos

*R Nath, L Saikia, S Baruah, T Gogoi

Departments of Microbiology (RN,LS), Ophthalmology (TG), Assam Medical College, Dibrugarh, Assam-786 002, Department of Ophthalmology (SB), Jorhat Medical College, Jorhat, Assam - 785 001, India

Correspondence Address: * Department of Microbiology, Assam Medical College, Dibrugarh, Assam-786 002, India, reema_44@rediffmail.com

Date of Submission: 02-Oct-2009
Date of Acceptance: 13-Jan-2010

Code Number: mb10055

PMID: 20404474

DOI: 10.4103/0255-0857.62505

Dear Editor,

Mycotic keratitis is an important cause of blindness in India. Microorganisms can invade corneal stroma if the normal corneal defence mechanisms are compromised. ^[1] Bilateral exophthalmos in graves disease can lead to failure of the eyelids to close completely during sleep, which leads to corneal dryness and damage. We report a case of bilateral simultaneous mycotic keratitis by two different fungi in a case of graves disease related bilateral exophthalmos without any obvious history of trauma. Isolation of two different fungi from either eye simultaneously is very rare. ^[2] A 45-year-old male farmer presented to our hospital with redness, pain, grittiness, and photophobia since 15 days in the left eye and since seven days in the right eye. There was no apparent history of injury. The patient was a known case of graves disease since two years and was treated with methimazole at a dose of 10mg daily and was presently euthyroid. Computerised Tomography revealed deposition of abnormal connective tissue in the orbit and extra ocular muscles. Examination of the eyes revealed visual acuity of finger counting at two metres in the right eye and finger counting close to face in the left eye. In the right eye a central corneal ulcer (3x3mm) involving the superficial layers of the cornea was seen. A larger (6x5mm) central white corneal ulcer, which extended to involve the inferior quadrant covering the full thickness of the cornea, was seen in the left eye.

Direct microscopy of the corneal scrapings revealed hyaline fungal hyphae from both the eyes. Culture yielded Aspergillus flavus from the left eye and Penicillium species from the right in all the C streaks inoculated in Saboraud's dextrose agar with chloramphenicol and blood agar media. The growth was seen within 48 hours in all the media. The patient was treated with topical 5% natamycin eye drops at hourly intervals for the initial seven days and thereafter at two-hour intervals with oral fluconazole 200 mg daily for two weeks and 150 mg daily for two weeks. Liver function was regularly monitored. The ulcer in the right eye healed after three weeks and the visual acuity improved to 6/24.The inflammation in the left eye decreased gradually and healed with opacity but visual acuity did not improve and remained at finger counting at face level after two months.

Simultaneously occurring bilateral keratitis is rarely reported. ^[2],[3],[4] Fungi are normally present as commensals in conjunctival flora of healthy eyes. ^[5] Though apparently there was no obvious history of injury in this case, failure of the eyelids to close completely may have led to dryness and compromised corneal barriers, which led to invasion by the fungi developing into ulcers. The relatively higher incidence of mycotic keratitis in India may be one reason for the bilateral infection. This case, though healed with opacity, runs the risk of trauma and recurrence of ulcer if not properly cared for with regular ocular examination. It may be concluded that simultaneous infection with two different fungi in the right and left eye do occur and microbiologists obtaining such isolates must report them as pathogens and not discard them as contaminants if the following criteria are met:

1. Growth of the same fungus on two or more solid media on the C streaks or semiconfluent growth at the site of inoculation on one solid medium
2. Same fungus grown on repeated scraping
3. Consistent with clinical signs and
4. Direct smear results are consistent with cultures.

References

1.	Bharathi MJ, Ramakrishnan R, Vasu S, Meenakshi, Palaniappan R. Aetiological diagnosis of microbial keratitis in South India- A study of 1618 cases. Indian J Med Microbiol 2002;20:19-24.  Back to cited text no. 1  [PUBMED]
2.	Prajna NV, Rao RA, Mathen MM, Prajna L, George C, Srinivasan M. Simultaneous bilateral fungal keratitis caused by different fungi. Indian J Ophthalmol 2002;50:213-4.  Back to cited text no. 2  [PUBMED]
3.	Gopalakrishnan K, Daniel E, Jacob R, Ebenezer G, Mathews M. Bilateral Bipolaris keratomycosis in a borderline lepromatous patient. Int J Lepr Other Mycobact Dis 2003;71:14-7.  Back to cited text no. 3  [PUBMED]
4.	Hoflin- Lima AL, Roizenblatt R. Therapeutic contact lens related bilateral fungal keratitis. CLAO J 2002;28:149-50.  Back to cited text no. 4
5.	Sehgal SC, Dhawan S, Chhiber S, Sharma M, Talwar P. Frequency and significance of fungal isolations from conjunctival sac and their role in ocular infections. Mycopathologia 1981;73:17-9.  Back to cited text no. 5  [PUBMED]

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