Study of clinical and microbiological profile of infective corneal ulcers at a tertiary care hospital in western Maharashtra

Introduction: Infective corneal ulcer is an important cause of visual impairment in developing countries. The present study was conducted to know demographic, clinical, and microbiological patterns of infective corneal ulcers in a tertiary hospital in western Maharashtra. Materials and Methods: This is a retrospective analytical study involving 68 eyes of 68 cases of infective corneal ulcer visited in the last two years. From medical records of all cases, details of history, clinical findings, and investigations were noted and data were analyzed. Results: Male to female ratio of study cases was 1.61:1 with age groups ranging between 18 to 90 years (mean 50.81 years). The main occupations of study cases were farming (28 i.e. 41.17%) and construction work (12 i.e.17.64%). Thirty-two (47.05%) cases had to present BCVA of <6/60. Corneal ulcers of size < 5 mm were seen in 37 (54.41%) cases and 19 cases (27.84%) had hypopyon. Central and paracentral ulcers were seen in 57 cases (83.82%). On Gram stain and 10% KOH mount, fungal etiology (26.92%) was seen more frequently than bacterial etiology (20.51%) and 4(5.88%) showed mixed organisms. In 37(54.41%) cases where no organisms were detected, 6 cases had clinical features of viral corneal ulcer. Conclusion: Infective corneal ulcers mainly affected working males involved in farming. Gram stain and KOH mount analysis showed fungal etiology more frequently than bacterial. Detailed history, clinical examination, and lab investigations of scrapings in cases of infective corneal ulcers are essential to know the clinical and microbiological pattern.


Introduction
Corneal infections can lead to corneal scarring and blindness if not diagnosed quickly and managed appropriately. Injuries, lid malpositions, topical medications like steroids, contact lens wear, and autoimmune diseases like rheumatoid arthritis are the various factors responsible for corneal ulcers [1,2].
A corneal ulcer is the second most important cause of infective blindness throughout the world, after trachoma. Also, it is the main cause of visual impairment and ocular morbidity in developing countries. Monocular blindness due to corneal diseases is seen in 1.5-2 million new cases annually worldwide. In India, about 6.8 million are blind because of corneal diseases [3,4]. Farming is the main occupation in rural parts of India, where accidental vegetative trauma to the cornea is common.
Majority patients of infectious keratitis present as a corneal ulcer with complaints of redness, pain, watering, photophobia, and diminution of vision. These cases pose a challenge to treating ophthalmologist as far as diagnosis and management are concerned. Thus optimal treatment in time can reduce serious complications like corneal perforation, endophthalmitis, or even panophthalmitis [5].
The prevalence of corneal ulcers varies according to the climatic conditions, occupations, and socioeconomic status of the people in different parts of the world [6].
The present study was conducted to know the demographic, clinical, and microbiological pattern of infective corneal ulcers in patients presented to our The history included symptoms of redness, pain, photophobia, watering, history of (h/o) trauma, contact lens use, prolonged use of any eye drops, h/o use of herbal medications, h/o swimming in the pool and h/o diabetes mellitus, Rheumatoid arthritis, etc. The details of examinations included visual acuity by Snellen's chart (unaided and aided), corneal sensation testing, anterior segment examinations by slit lamp, IOP measurement by non-contact tonometry, sac syringing, fundus examination by indirect ophthalmoscopy, etc. Routine lab investigations and microbiological findings of corneal scrapings were noted.
The corneal ulcer was diagnosed by slit-lamp examination showing greyish haze or loss of clarity in cornea and epithelial defect after staining with fluorescein strip. Slitlamp photographs and color-coded diagrams were recorded for documentation and to assess the progress. It is also important in medicolegal cases with h/o trauma.
Then after putting 0.5 % proparacaine eyedrop to anesthetize the eye, corneal scraping was taken by an ophthalmologist under a slit lamp view. By using a 15 no. surgical blade the edge of the ulcer was scrapped and the sample was collected on two glass slides. One slide was sent for Gram staining to detect bacterias and other for 10% KOH mount for the detection of fungal hyphae.
The viral corneal ulcer was diagnosed clinically if characteristic dendritic or geographic pattern associated with loss of corneal sensations and the presence of skin lesions were seen. Acanthamoeba ulcer is diagnosed if ring-shaped stromal infiltrates with hypopyon are observed [7].
Statistical analysis-The data was arranged in an MS Excel sheet and statistical analysis was done. The number and percentage of patients according to age groups, gender and occupations were calculated. Also, the percentage of patients with different clinical features of corneal ulcer and microbiological etiology was calculated.

Results
Sixty-eight eyes of 68 patients with infective corneal ulcers were included in this study. The age group of patients involved in the study ranged from 18 to 90 years. The majority (62 i.e. 88.23%) patients were in the age group of 26 to 70 years (Table 1), mean age was 50.81 years and male to female ratio was 1.61:1 ( Table 2). Twenty-eight patients (41.17%) were farmers by occupation and 12 patients (17.64%) were construction workers (Table 3).

Original Research Article
Tropical Journal of Ophthalmology and Otolaryngology Available online at: www.medresearch.in 102|P a g e Out of 68 eyes, 41 eyes had conclusive scraping reports on Gram stain and 10% KOH mount. Fungal etiology was found in 21 (26.92%) compared to bacterial etiology in 16 (20.51%) and 4 cases (5.88%) showed mixed organisms. No organisms were detected in the corneal scrapings of 37 patients (54.41%), out of which 6 had clinical features of viral keratitis (Table 6).

Discussion
Infective corneal ulcer causes significant ocular morbidity and often blindness. A proper history and clinical examination in detail are very important for the diagnosis and management of corneal ulcers [7].
In the present study, male preponderance was seen for infective corneal ulcers. Male to female ratio of 1  [4,7,8].
By occupation, the majority of patients in the present study were farmers (28 i.e. 41.17%) followed by construction workers ( 12 i.e. 17.64%) and factory workers (4 i.e. 5.88%). So occupational injuries were seen in the majority of the patients (44 i.e. 64.7%). In similar studies by Mohod et al and Srinivasan et al, farming was found to be the main occupation in the majority of patients with corneal ulcers [10,11]. Gopinathan U et al reported that agricultural workers have 1.33 times greater risk of developing infective Keratitis. Farmers are more prone to vegetative trauma, which is the leading predisposing factor of infective corneal ulcers in developing countries [12]. Also, construction workers, factory workers, and welders are prone to accidental superficial and stromal corneal foreign bodies leading to infective corneal ulcers.
In the present study, 37 eyes (54.41 %) had corneal ulcers measuring less than 5 mm and 31 ( 30.88%) had more than 5 mm. Khare P et al and Puri LR et al in their study noted corneal ulcer of less than 5 mm size in 74.53 % and 78.3% respectively and more than 5mm seen in 20.37% and 21.60% respectively [13,14].
In the present study, the involvement of central and paracentral cornea was seen in 57 ( 83.83% ) patients, while peripheral corneal involvement was noted in 11(16.17 % ) patients. Khare P et al noted the involvement of central and Para central regions of the cornea in 76.15 % patients and peripheral involvement in 2.1% patients [13]. Puri LR et al noted central and Para central involvement in 45.2% patients while peripheral involvement in 7% patients [14].
In this study, corneal scrapings from the corneal ulcer site sent for microbiological examination for gram stain and 10% KOH mount revealed presence of bacteria in 16 (20.51 %) patients, fungal hyphae in 21 (26.52%,) mixed organisms in 4 (5.2 % )and no organisms were detected in 37 (39.74 %) patients.
A study by Amrutha KB et al noted the detection of bacteria in 67.17%, fungi in 25.37%, and mixed growth in 7.46% and no organisms in 33% patients [16].
The findings of these two studies differ from the present study regarding the percentage of bacterial and fungal etiologies. In the present study fungal etiology was detected more than bacterial etiology. This can be related to the farming occupation of the people in this region of western Maharashtra where vegetative trauma is more common.
The causes of non-detection of microorganisms on gram stain and KOH mount in the present study included viz initiating topical antimicrobials before corneal scraping, the faulty technique of corneal scraping, and inadequate sample.

Limitations:
The sample size was comparatively small in the present study and the study did not include culture and sensitivity of corneal scrapings to isolate the specific microorganisms. So future studies with larger sample sizes involving culture and sensitivity of corneal scrapings will help in finding specific microorganisms with their sensitivity to antimicrobials. Also, other microorganisms causing keratitis like acanthamoeba and microsporidia should be kept in mind and searched accordingly.

Original Research Article
Tropical Journal of Ophthalmology and Otolaryngology Available online at: www.medresearch.in 104|P a g e Seasonal occurrences of specific keratitis patterns will further help in formulating new practice protocols in cases of infective keratitis

Conclusion
Infective corneal ulcers are more common in working males. In western Maharashtra, as farming is the main occupation where vegetative injuries are more common, the prevalence of fungal corneal ulcers is more compared to other causative microorganisms. People working at construction sites and in factories are also prone to ocular injuries leading to an infective corneal ulcer. Gram stain and KOH mount of corneal scrapings are simple and quick OPD investigations helpful in the detection of the type of microorganisms.
Detailed history, clinical examination, and lab investigations of scrapings in cases of infective corneal ulcers are essential to know the clinical and microbiological pattern.

What does the study add to the existing knowledge?
The people working in fields, factories, and construction should be educated regarding the protection of eyes and need of urgency to visit an ophthalmologist in case of any eye injury. In suspected infective corneal ulcer patients whenever possible anti-microbials should not be started before gram stain and KOH mount of corneal scraping to avoid masking of infection. Self-treatment and home remedies should be avoided in any eye complaint.