|Year : 1976 | Volume
| Issue : 1 | Page : 15-18
Fungal flora of conjuctival sac in health and disease
Satya Arora1, SC Tyagi2
1 Asst. Prof. Microbiology, Medical College, Amrritsar, India
2 Prof. of Microbiology, Medical College, Amritsar, India
Asst. Prof. Microbiology, Medical College, Amrritsar
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Arora S, Tyagi S C. Fungal flora of conjuctival sac in health and disease. Indian J Ophthalmol 1976;24:15-8
Ocular fungus infections are becoming increasingly common these days. The increase has been associated with the increasing use of corticosteroid and wide spectrum antibiotics,,. Although these fungi do not cause any reaction in the normal conjunctiva, they may be pathogenic when introduced into the eye as suggested by Anderson and Chick. The incidence of normal fungal flora in healthy eyes shows considerable variation in reported series from 10.3 per cent to 27.9 per cent. In India few studies have been reported so far ,,, Surprisingly no such data is available in this part of the country as no systematic study has been done so far.
The present study was undertaken with a view to determine the range of species of fungus present as commensals in the conjunctiva) sac of subjects who show no disease of the outer eye in both sexes at all ages. The proportion of cases of external eye disease from which fungi can be cultured and the possible role of fungi in causing the disease, and to find out any correlation between the bacterial and mycotic flora in healthy and diseased eye.
| Material and Methods|| |
One hundred patients with no clinical evidence of ocular infections, otherwise healthy were selected. The subjects were either the patients who attended the Medical College and Hospital for refractive errors or comprised of medical students and technical staff of the college.
Fifty patients showing some form of disease of outer eye were selected. Conjunctival swabs were taken and streaked over the surface of blood agar medium and two slants of Sabouraud's, agar medium for bacteria and fungi. The cultures for fungi were incubated at 25°C and 37°C. The culture bottles were examined for growth after 48 hours and subsequently at interval of 2-3 days upto 2 weeks. The fungi were identified on the basis of colonial characters and microscopy. In addition, biochemical tests were put up particularly for yeast fungi. Bacterial cultures were incubated at 37°C for 24 hours and identified by conventional methods.
The cases of eye diseases not responding to the antibiotics repeated cultures were done to exclude fortuitous fungal contamination.
| Observations|| |
Examination of the conjunctival swab from 100 cases without any disease of the outer eye showed the presence of fungi in 13 cases, giving an incidence of 13 per cent. They were in the age group of 1-60 years. The number of males and females were 54 and 46 respectively. About two-thirds of the positive cases were males and all were either agriculturists or were doing part-time agriculture work. [Table - 1] shows the species and the frequency of fungi isolated. The species most frequently isolated were Aspergillus, Penicillium and Candida Albicans.
Positive mycotic cultures were obtained from 12 patients (24 per cent) suffering from the various diseases of the outer eye [Table - 2].
The incidence of fungi from the corneal ulcer is higher. The incidence was higher in males (70 per cent males and 30 per cent females) as men are more prone to injury. Out of 12 positive cases 8 were agricultural labourers, 2 washermen and 2 housewives. 10 cases had a history of trauma with vegetable matter while working in the fields and by knitting needles. There was no history of having any treatment except local bandage. As is evident from the [Table - 2],
Aspergillus sp., Candida albicans, Hormodendrum sp. and Penicillium sp. were isolated.
All cases had suitable local antibiotics supplemented by systematic antibiotics. Out of 12 cases 2 had proven refractory to treatment. To establish cause and its effect relationship attempt was made by repeated culture. Same fungi were isolated in repeated cultures. These two patients were then put on antifungal treatment and all responded well and later on they were sterile mycologically.
The results of the bacterial cultures isolated from healthy eyes were compared with those of the patients with diseased eye [Table - 3].
Bacteria were isolated in 20 out of 100 normal cases (20 per cent) and in 12 out of 50 diseased cases (24 per cent). The conjunctival bacterial flora was more or less same in either sex and also the incidence remains more or less the same with age. Staphylococcus was most frequently isolated from both healthy and diseased eyes.
| Discussion|| |
In the present series various species of fungi were isolated in 13 per cent of the cases with apparently healthy outer eyes. Our figures compare favourably with Sinha and Das who reported 13.7 per cent incidence. Srinivasa Rao and Rao in their studies found an incidence of 24.3 per cent. However, somewhat lower figures were reported by other workers. Das Gupta reported an incidence of 8.5 per cent while Saxena reported 8.7 per cent. This variable incidence suggests the importance of number of eyes investigated, methods employed, ecological differences in temperature and humidity of the place. Fungal isolation seems to be affected by age as younger age group had the lowest incidence (2.0 per cent) which increased to 6.0 per cent in the old age. Hammeka and Ellis also demonstrated this variation. There was predominance of fungal incidence in the males and this could be attributed to the outdoor work in agricultural area in which males take part more than females and so are more prone to injury. This is in accordance with the finding of Saxena.
Positive fungal cultures were obtained in 24 per cent suffering from the various diseases of the outer eye. Similar result was obtained by Das Guptas. Ainley and Smith described a series of 26 patients with disease of the outer eye of whom 34.6 per cent had positive culture. Majority of these were adults or elderly persons. Most of our cases were agricultural labourers and so were often subjected to injury to the eye which predispose them towards the development of disease. Balakrishnan reported 30 cases in agricultural labourers. Zimmerman collected 20 cases which had followed some injury to the eye. Aspergillus sp. constituted the major causative agent (58.5 per cent). This is in accordance with the findings of Balakrishnan.
In the present study no evidence was obtained which suggested a causal relationship between the presence of fungus and the diseased eye from which it was isolated except in 2 patients as suggested by the following considerations :
- Lack of response to antibiotic treatment.
- Repeated positive fungal cultures from diseased eye which excludes fortuitous contamination.
- Fungal growth was obtained only from the affected eye and no bacteria isolated.
- The patient became symptom free with antifungal treatment.
Positive bacterial cultures were obtained in 20 per cent and 24 per cent of the healthy and diseased eyes respectively. Similar results were obtained by Srinivasa [Rao] The incidence of bacteria and fungi in normal and diseased eye remained more or less the same with age and sex. Bacteria and the fungi were present together in 8 cases with healthy eyes and 10 cases with diseased eyes while in others with positive mycotic cultures no bacteria could be isolated. It thus appears that there is no definite correlation between the bacterial and mycotic flora in healthy and diseased eyes.
| Summary|| |
Conjunctival swab from 100 healthy and 50 diseased eyes were cultured for the isolation of Bacteria and fungi. Fungi were grown in 13 per cent of healthy eyes and 24 per cent of the diseased eyes. Most of the cases were of agricultural labourers and maximum cases were seen in higher age group. Aspergillus was the commonest species isolated. In two of the diseased cases, fungus proved to be the causative agent.
The incidence of bacterial growth was 20 percent in healthy and 24 percent in diseased eye.
| References|| |
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[Table - 1], [Table - 2], [Table - 3]