|Year : 2022 | Volume
| Issue : 3 | Page : 101-104
Microbial profile of infectious corneal ulcer in a remote Himalayan teaching hospital in Himachal Pradesh (India)
Amit Chopra1, Seema Solanki2, Rajan Sharma1, Ravinder Kumar Gupta1
1 Department of Ophthalmology, M. M. Medical College and Hospital, Solan, Himachal Pradesh, India
2 Department of Microbiology, M. M. Medical College and Hospital, Solan, Himachal Pradesh, India
|Date of Submission||27-Dec-2021|
|Date of Decision||23-Jul-2022|
|Date of Acceptance||02-Nov-2022|
|Date of Web Publication||1-Dec-2022|
M. M. Medical College and Hospital, Kumarhatti, Solan, Himachal Pradesh
Source of Support: None, Conflict of Interest: None
Purpose: To study the microbiological profile of clinically diagnosed infectious keratitis cases in tertiary care hospitals in Solan, HP (India). Design: The study design involves prospective cross-sectional study. Materials and Methods: It was a prospective cross-sectional study that included clinically diagnosed corneal ulcer patients from September 1, 2018 to September 1, 2019. The demographic data, predisposing risk factors, clinical details, previous treatment history, investigations, treatment, and visual outcomes were analyzed. Results: A total of 36 patients were included in the study, and no significant difference between the number of males and females was noted (P = 0.74). The most common etiology of ulcer was corneal trauma in 25 (69%) patients. Injury with vegetative material was the most common mode of injury (18 of 25, 72%), followed by injury during construction work (3 of 25, 12%). Twelve of 36 (33%) cases were fungal, 6 (16%) were found to be bacterial and 2 (5%) cases had mixed organisms. The most common organism isolated was Fusarium spp. in 8 (40%) cases. The most common bacterial isolate was Staphylococcus aureus in 4 (20%) cases, followed by one each of Streptococcus pneumonia (5%) and Pseudomonas spp. (5%). Thirteen patients (36%) reached outpatient department between 7 and 14 days and 15 (42%) patients 2 weeks after the start of symptoms with no significant difference in the two genders (P = 0.97). Conclusion: Majority of infectious corneal ulcers in our region are fungal due to injuries during predominantly agriculture-based lifestyles and need urgent management.
Keywords: Corneal ulcer, fusarium, infectious keratitis, Staphylococcus aureus
|How to cite this article:|
Chopra A, Solanki S, Sharma R, Gupta RK. Microbial profile of infectious corneal ulcer in a remote Himalayan teaching hospital in Himachal Pradesh (India). J Clin Ophthalmol Res 2022;10:101-4
|How to cite this URL:|
Chopra A, Solanki S, Sharma R, Gupta RK. Microbial profile of infectious corneal ulcer in a remote Himalayan teaching hospital in Himachal Pradesh (India). J Clin Ophthalmol Res [serial online] 2022 [cited 2023 Jan 31];10:101-4. Available from: https://www.jcor.in/text.asp?2022/10/3/101/362501
Infectious keratitis is a major cause of uniocular blindness in the developing world. Around 5% of blindness worldwide may be attributed to ocular trauma and the resulting infection of the cornea. The incidence of microbial keratitis in developing countries like India is higher because of the lack of adequate primary ophthalmic health care and dependence on high-risk professions such as agriculture and farming. Infectious keratitis is an important cause of unilateral blindness ranging from 1.5 to 2 million cases per year globally. An intact corneal epithelium acts as a mechanical barrier against microorganisms which can penetrate through if the epithelium is breached due to trauma or surgery. The avascular stroma is particularly susceptible to microbes, and many patients can have poor clinical outcomes if prompt antimicrobial therapy is not initiated. Identification of pathogen and initiation of immediate therapy based on identified organism represents the key to success in the management of infectious keratitis.
Our region (Himachal Pradesh) is a Himalayan state with most people residing in remote locations often taking long journeys to reach the nearest health facility. Knowledge on diagnosing cornea ulcer, its empirical treatment, and urgent referral is of paramount importance to decrease further complications. The aim was to study the microbiological profile of clinically diagnosed infectious keratitis cases in a tertiary care hospital in Himachal Pradesh.
| Materials and Methods|| |
All patients who were clinically diagnosed with infectious keratitis at the ophthalmology outpatient department (OPD) of MMMC and H Solan, Himachal Pradesh, India, from September 1, 2018 to September 1, 2019, were included in the study. Patients with Mooren's ulcers, sterile neurotropic ulcers, interstitial keratitis, and ulcers associated with autoimmune conditions were excluded from the study. A standardized protocol was followed for each patient, with corneal ulceration for the evaluation of microbiological features and clinical findings. All patients were examined according to the standard protocol after obtaining informed and written consent. Ethical committee approval for the study was taken from the institutional review board.
After taking a detailed history, any mode of injury, time since the event, and any medication taken for the same were also recorded. A slit lamp examination was done to note the clinical characteristics of the ulcer, including size, shape, depth, floor, margins, and vascularization. Scraping was done under topical anesthesia (4% lignocaine) by scraping the base and edges of the ulcer under magnification of slit lamp using sterile Bard-Parker knife. Samples were taken immediately and subjected to Gram staining, and potassium hydroxide mount for microscopy. Furthermore, the material was inoculated on blood agar, MacConkey agar for bacterial, and Sabouraud dextrose agar for fungal culture.
The Statistical Package for the Social Sciences (SPSS) for Windows, Version 22.0. Released 2013. Armonk, NY, USA: IBM Corp. was used to perform statistical analyses. Chi-square test was used to compare the culture isolate obtained and clinical/microscopic findings based on age groups and gender among study patients. The level of significance (P value) was set at P < 0.05.
| Results|| |
A total of 36 patients were included in the study, and the most common age group was 41–60 years (n = 12 of 36, 33%), followed by 21–40 years (n = 10 of 36, 28%). No significant difference in the number of males (n = 19 of 36) and females (n = 17 of 36), i.e., 53% versus 47% (P = 0.74). The most common etiology of ulcer was corneal trauma in 25 out of 36 patients (69%). Six patients gave a history of topical corticosteroids use (n = 6 of 36, 17%). One patient had a recent history of pterygium excision and developed infiltrate at the excision site on the cornea and the other had pseudophakic bullous keratopathy with corneal infiltrate (n = 2, 6%). Two patients had a history of severe dry eye and one had postchemical injury cicatricial entropion with trichiasis (n = 3, 8%). Of the trauma cases, injury with plant stalk/vegetative matter was reported in 18 of 25 (72%) patients, followed by injury during construction work in 3 of 25 (12%) cases [Figure 1].
|Figure 1: Distribution of etiology of corneal trauma causing corneal ulcer among study patients|
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The number of cases showing positive results on culture was 20 of 36 (56%) cases. The most common bacterial isolate in culture-proven cases was Staphylococcus aureus in 4 of 20 (20%) cases, followed by one each of Streptococcus pneumonia (5%) and Pseudomonas spp. (5%). 2 (10%) patients had mixed infection and culture showed both Strep. Pneumonia and Fusarium spp. Fusarium was the most common fungus detected in cultures in 8 of 20 (40%) cases and was the most common organism isolated, followed by Aspergillus in 3 of 20 (15%) cases and Candida spp. in 1 (5%) case [Figure 2]. One case of viral keratitis (Herpes simplex) was treated based on clinical diagnosis. In our study, 13 (36%) patients reached OPD between 7 and 14 days and 15 (42%) patients 2 weeks after the start of symptoms, with no significant difference in the two genders (P = 0.97).
|Figure 2: Distribution of culture isolate obtained from corneal scraping among study patients|
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| Discussion|| |
Infectious keratitis is a vision threatening pathology which requires urgent antimicrobial treatment. The incidence of microbial corneal ulcers is high in the Indian subcontinent and varies from 113/100,000 to 799/100,000 in Nepal. It is seen in all age groups, but a higher prevalence is observed in the physically active adult group and males have a higher preponderance than females. However, in our study, no statistically significant difference was observed (P = 0.74), most probably because both genders and all age groups equally participate in farming activities, as agriculture is one of the most important sources of livelihood in the hilly state of Himachal Pradesh.
The etiology shows geographical variation as the statistics from Western developed countries shows predominantly bacterial etiology as compared to fungal keratitis in developing countries. This is due to the increased risk of trauma from vegetative matter as more dependence on agriculture for livelihood than the west and it is the most common predisposing factor., In our study as well, the most common etiology for corneal ulcers was trauma (69%). Of these, 18 (72%) patients had injury with plant stalk or other vegetative matter, which is similar to another study from the Himalayas, where 53% of cases had similar injuries. Furthermore, no cases in our series had a history of contact lens wear which was similar to the above study.
The culture-positive rate in our study was 56% (20/36) which was similar to Tewari et al. (59.3%) and Gopinathan et al.(60.4%) but much less than Malhotra et al.(82.5%) who credited the high yield of culture positives to the direct inoculation of culture specimen in OPD itself without transportation to the laboratory. Bacterial isolates were 17% of the cases (n = 6) and 33% (n = 12) of corneal ulcers were fungal on culture.
Bacterial keratitis accounts for around 30% of corneal ulcers in South India (29.3% to 32.77%) as compared to a larger proportion in the Northern Indian subcontinent, reported as high as 63.2%. S. aureus was the most common single bacteria isolated in cultures (20% of all culture-proven cases), similar to one other study from our region, followed by Strep. pneumonia and Pseudomonas spp. (5%). However, Strep. pneumonia is the predominant bacterial isolate reported from southern India, accounting for 35.9% of bacterial isolates and Staph epidermidis (42.3% of bacterial isolates), as reported by Gopinathan et al.
The majority of fungal keratitis is caused by filamentous fungi [Figure 3]a, [Figure 3]c and [Figure 3]d. Fusarium spp. are more common in southern India,, and Aspergillus species may be the more common fungal pathogen in Northern India (40.1%–41.2%).,, In our study, though, Fusarium spp. was the most common fungus detected in cultures in eight cases and was the most common organism isolated (40%), followed by Aspergillusin 3 (15%) cases and Candida spp. in 1 (5%) case. Malhotra et al. from neighboring Himalayan state also found Fusarium to be the most common fungal isolate. Candida is a rare pathogen in fungal ulcers in the tropical world, but it is very common in the Western world.
|Figure 3: (a) Resolving infiltrate in fungal ulcer. (b) Large perforation in fungal corneal ulcer. (c) Raised infiltrate with hyphate margins suggestive of fungal corneal ulcer. (d) Fungal hyphae seen on 10% KOH mount of scraping from c. KOH: Potassium hydroxide|
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In our study, 6 (17%) cases were already started on topical corticosteroid therapy either from primary health centers or over-the-counter medication, which has also been reported by other authors., Steroids are contraindicated in the treatment of fungal keratitis and can be catastrophic., One patient who was on two topical steroids (betamethasone and dexamethasone eye drops) had a large perforated fungal ulcer and was referred to a higher center for therapeutic penetrating keratoplasty on an emergency basis [Figure 3]b.
The limitation of our study was the small number of patients included in the study, and hence, the results can not be compared to other studies. Most patients took more than 1 week to reach the OPD, and 6 (17%) took more than 3 weeks to report even though on treatment from the primary health care level. Most patients take long journeys to reach tertiary-level health care because of the difficult Himalayan terrain. Furthermore, often in developing countries, eye care at the primary health care level is inadequate because of the low number of ophthalmic officers posted and the deficient stock of first-line antimicrobial drugs. Primary health care can be educated on the diagnosis and first line of antimicrobial treatment in corneal ulcers. Some patients are also treated by quacks for corneal foreign bodies with unsterilized instruments leading to worsening of ulceration. Simple strategies like topical application of antibiotics and urgent referral to the nearest ophthalmic care unit should be initiated.
| Conclusion|| |
The most common ulcers were fungal (Fusarium spp.), followed by Gram-positive bacteria (S aureus) and it is well known that fungal corneal ulcers have greater chances of requiring surgical intervention.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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