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Year : 2016  |  Volume : 34  |  Issue : 1  |  Page : 72--75

Current spectrum of oculomycosis in North India: A 5-year retrospective evaluation of clinical and microbiological profile

S Verma1, V Sharma1, A Kanga1, R Sharma2, A Angrup1, K Mokta1, A Garg1,  
1 Department of Microbiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
2 Department of Ophthalmology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India

Correspondence Address:
S Verma
Department of Microbiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh
India

Abstract

Oculomycosis is a major cause of visual impairment. Eye pain, redness, discharge, diminution and photophobia are presenting features. We collected corneal scraping, vitreous, aqueous fluids and conjunctival swabs after the slit-lamp examination. Ophthalmological findings were hypopyon, stromal congestion, conjunctival congestion and epithelial defect. Direct microscopy of 10% potassium hydroxide (KOH) wet mounts, gram staining, fungal and bacterial cultures were performed. Fungal isolates were obtained in 24% patients with equal number of both sexes and average age 49 years. KOH revealed fungi in 73% samples and 43.33% were positive on Gram staining. Fusarium spp. (36.66%), Aspergillus spp. (23.33%) and melanised fungi (20%) were common etiological agents. Fusarium spp. was more often associated with complications. Trauma was a predisposing factor in 65% cases and occurred mainly with vegetable matter. The majority responded to the conservative management with 5% natamycin and four patients required surgery.

How to cite this article:
Verma S, Sharma V, Kanga A, Sharma R, Angrup A, Mokta K, Garg A. Current spectrum of oculomycosis in North India: A 5-year retrospective evaluation of clinical and microbiological profile.Indian J Med Microbiol 2016;34:72-75

How to cite this URL:
Verma S, Sharma V, Kanga A, Sharma R, Angrup A, Mokta K, Garg A. Current spectrum of oculomycosis in North India: A 5-year retrospective evaluation of clinical and microbiological profile. Indian J Med Microbiol [serial online] 2016 [cited 2019 Oct 16 ];34:72-75
Available from: http://www.ijmm.org/text.asp?2016/34/1/72/174104

Full Text

 Introduction



Ophthalmic mycosis constitutes common infections causing morbidity and preventable blindness. The fungi frequently involve the cornea and intraocular chambers.[1] An incidence of 7–63% is documented from India.[2],[3] The etiological agents vary with the environmental and host factors and prior healthcare exposure. Antecedent traumas with vegetable matter, medication with antimicrobials or steroids, wearing of contact lenses or ocular surgeries are allied with an ocular mycosis.[2],[3],[4] Early diagnosis may prevent the visual disability. The present compilation of retrospective data attempts to assess the epidemiological variables implicated, the clinical profile and the spectrum of etiological fungi in the foothills of western Himalayas. The knowledge of epidemiological profile of mycotic agent will help in presumptive treatment where cultures are negative or facilities do not exist.

 Materials and Methods



A retrospective study of oculomycosis was conducted from January 2009 to December 2013 at a tertiary care teaching institute. The socio-demographics, clinico-etiological profile and management outcome was retrieved from hospital records. Hundred and ten corneal scrapings, 12 vitreous fluids, 4 aqueous fluids and one conjunctival swab were collected by an ophthalmologist from 125 patients. Samples were inoculated on blood and chocolate agar for bacterial culture, Sabouraud's chloramphenicol dextrose agar for fungal culture and submitted to the Mycology Laboratory for incubation and identification.[5] The direct microscopy of 10% potassium hydroxide (KOH) wet mount and gram staining of smears were performed. The culture was considered significant if the same isolate was obtained in more than one tube or sample, isolate obtained in one tube with fungal hyphae on the direct microscopy or repeat isolation of the same agent. The final identification was done on the slide cultures after visualizing the lactophenol cotton blue wet mounts and yeast by germ tube test, urease test, Dalmau's method and sugar fermentation. Topical antifungal treatment was initiated after direct microscopy. Natamycin 5% eye drops hourly instillation with atropine drops thrice daily and oral itraconazole 200 mg or fluconazole 150 mg daily was started where preliminary investigations substantiated mycosis. Prophylactic antibiotic eye drops, 1 hourly were prescribed for bacterial co-pathogens. Excision of the cornea with therapeutic keratoplasty was done in advanced and refractory corneal infection. Intravitreal amphotericin B or voriconazole injections were given for fungal endophthalmitis where critically indicated and guided by the clinical judgment.

 Results



A total of 125 patients presenting with eye ailments suspected of fungal origin were studied. This included 66 (52.8%) men, 59 (47.2%) women and 85% were rural inhabitants. Oculomycosis was established by culture in 30 subjects giving the etiological prevalence of 24% with an equal number of males and females. The age ranged between 12 and 80 years average being 49 years. Eighteen (60%) cases were reported during the rainy season and early winter. The presenting complaints frequency-wise were eye discharge (82.6%), pain (78.26%), redness (65.21%), dimness of vision (59.52%) and photophobia (30.43%). The common predisposing factors were trauma in 65.21% subjects with vegetable matter, soil, dust or sand, manipulation of eye by unqualified persons (21.73%), diabetes mellitus and previous ocular surgery (13.04% each).

A rapid deterioration of visual acuity to <6/18 was seen in 15/23 cases (65.21%). The corneal ulcers were associated with stromal infiltrate (43.47%), satellite lesions (13.04%) and feathered margins in 8.69%. the slit-lamp examination revealed hypopyon (60.86%), conjunctival congestion (56.52%), epithelial defect (43.47%), non-reactive pupils (30.43%) and scleral congestion (26.08%).

Fungi isolated were Fusarium spp. [Figure 1] in 11 cases, Aspergillus spp. in seven cases which included four Aspergillus fumigatus and A. niger, A. flavus and A. nidulans in one case each, dematiaceous fungi in six cases. The sample wise distribution included 27 isolates from corneal scrapings and four isolates from the vitreous tap (Fusarium, A. fumigatus, Acremonium and Candida tropicalis in one each) [Figure 2]. All samples of aqueous fluid and conjunctival swab were sterile. Of the 30 culture positive cases, 10% KOH preparations showed the fungal hyphae [Figure 3] in 22 (73.33%) and Gram smears in 13 (43.33%) cases. The mixed infection was observed in three cases which included Staphylococcus aureus in two and Streptococcus pneumoniae in one.{Figure 1}{Figure 2}{Figure 3}

Seventeen patients with surface oculomycosis were managed conservatively on topical 5% natamycin hourly, and atropine 3 hourly eye drops for 2 days followed by 2 hourly drops. Topical cefazoline, gentamycin, clindamycin or vancomycin was administered 6 hourly for bacterial co-pathogens. The two patients were given glue application with bandage contact lens for impending perforation. Four subjects are requiring operative intervention. The predisposing factors in these included diabetes mellitus, post-cataract surgery and trauma. Fusarium spp. was isolated in two and A. niger and Acremonium spp. in one each.

 Discussion



Fungi are an important cause of ocular infections leading to the visual impairment.[2],[3] Trauma with vegetable matter, sand and metallic objects is the key antecedent factor.[2],[3],[4],[6],[7] Increased incidence is witnessed during harvest season.[1],[3],[7] We observed an incidence of 60% during fall and early winter when orchard activities are at peak and ocular trauma common. Manipulation of the eye with unsterile objects by unskilled persons is a risk factor as it may introduce fungal conidia in the eye.

Fungi constitute the normal flora of conjunctiva which invades cornea in immune-compensated conditions such as diabetes mellitus or use of topical steroid and antibiotics.[7],[8] Previous ocular surgeries predispose to keratomycosis, as seen in four patients in the present study.[9],[10] Wearing of contact lenses was not a contributory factor in our subjects unlike previous reports as the majority of our patients were ruralities not conversant with a contact lens usage.[7],[10],[11] Both men and women engaged in outdoor jobs showed higher incidence contrary to the earlier reports.[3],[6],[7],[8],[9],[11],[12],[13]

The presenting complaints are foreign body sensation, eye pain, redness, discharge, photophobia and dimness of vision.[5],[13] Our patients narrated such complaints except the foreign body sensation which is probably forgotten as pain and vision impairment start. The slit-lamp examination reveals hypopyon as a characteristic feature.[5] We observed hypopyon in 60% cases correlating with earlier reports of 45–66%.[7],[13],[14],[15] Hypopyon may not be visualized in the patients attending the health facility earlier than a week.[13],[16] The visual acuity was gauged poorer than 6/12 in the majority of our patients correlating with 53.66% in a previous study.[4] Vision is the main concern of the patient and the ophthalmologist and such history is perpetually available to a pilot clinical suspicion.

The diverse clinical picture simulating the bacterial and parasitic infections is non-diagnostic thereby necessitating the laboratory confirmation. Fungi are visualized in KOH wet mounts in 62–90.9% cases.[2],[7],[11],[13],[17] We observed hyphae in 73.33% wet mounts in culture-proven cases. Gram staining with a reasonable positivity of 43.3% in the present account is documented in the range between 33% and 73%.[2],7,[16],[17],[18],[19] It also assists the identification of bacterial co-pathogens. The mixed bacterial and fungal keratitis is reported in 1.85% cases from South India against 10% of our cases.[20]

The spores of Aspergillus spp. can tolerate hot and dry weather conditions; inhabit soil, dust and decaying organic matter.[1]Fusarium, Bipolaris and Curvularia spp. are plant pathogens found mainly in cereal crops, plant debris, grasses and soil.[1]Candida spp.are implicated in prior ocular surface disease or surgeries and steroid or antibiotic therapies.[10],[12] These are the common isolates cultured from the infected eyes in the previous and present study.[21] Thomas described Fusarium solani keratitis as more devastating, causing perforation or malignant glaucoma exhibiting the raised intraocular tension progressing rapidly to complete destruction of the eye.[16] Two of our subjects, who underwent surgery, had an infection with Fusarium spp. The raised intraocular tension was notable in three cases out of eleven tested and isolates in these were Fusarium spp. in two and Bipolaris spp. in one. The patients managed conservatively with continued medication for 6 weeks, recover well though a few require surgical intervention.

 Conclusion



Oculomycosis is an infective condition involving healthy eyes, which leads to grave consequences. If strong clinical suspicion of fungal keratitis exists, KOH and Gram's staining are useful in diagnosis, in resource-poor situations. The presumptive treatment should be directed against Fusarium species.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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