Viral keratitis is a major cause of infectious corneal blindness and preventable visual impairment worldwide. Herpes simplex virus (HSV) is the most common etiological agent, while varicella-zoster virus (VZV), adenovirus, and cytomegalovirus (CMV) are less frequent causes of viral corneal infection.1,2 HSV keratitis is characterized by recurrent episodes due to viral latency and reactivation, which may result in corneal scarring, stromal inflammation, neovascularization, endothelial involvement, and permanent visual impairment.3,4 The burden is particularly high in developing countries because of delayed diagnosis, limited awareness, and restricted access to specialized ophthalmic care.2,4 The clinical manifestations of viral keratitis vary according to the causative virus and the depth of corneal involvement, ranging from superficial punctate keratitis and dendritic epithelial ulcers to stromal keratitis, disciform keratitis, necrotizing stromal disease, and endotheliitis.1,3 Patients commonly present with redness, pain, watering, photophobia, foreign body sensation, and diminished vision. Assessment of demographic characteristics, laterality, lesion morphology, and the corneal layer involved is essential for accurate diagnosis, appropriate treatment, and prediction of visual prognosis.2,3 Despite numerous studies, considerable regional variation exists in the demographic profile, clinical presentation, and pattern of corneal involvement in viral keratitis. Data from tertiary care centres in India remain limited, highlighting the need for locally relevant evidence to improve diagnosis and patient management.2-4 Therefore, the present study was undertaken to evaluate the clinical profile and spectrum of viral keratitis among patients attending a tertiary care centre. The objectives were to describe the demographic and clinical characteristics of patients, determine the distribution according to age, gender, and laterality, evaluate presenting ocular symptoms, assess lesion morphology and corneal layer involvement, and compare the distribution of viral keratitis between rural and urban populations.

This prospective observational study was conducted over a period of one year from October 2015 to September 2016 in the Department of Ophthalmology, A.J. Institute of Medical Sciences, Mangalore, after obtaining approval from the Institutional Ethics Committee. The study aimed to evaluate the clinical profile and spectrum of viral keratitis among patients attending a tertiary care centre. A convenience sampling method was adopted, and all eligible patients presenting during the study period were included. A total of 72 patients diagnosed with viral keratitis constituted the study population. Consenting patients with clinical features suggestive of viral keratitis, including those with associated superadded bacterial or fungal infection, were enrolled after obtaining written informed consent. Patients who were unwilling to participate or who did not demonstrate clinical features consistent with viral keratitis were excluded from the study. A detailed clinical history was obtained from each participant using a predesigned proforma, followed by a comprehensive ophthalmic examination. Demographic characteristics, including age, gender, and place of residence, were documented. Clinical evaluation included assessment of presenting symptoms, laterality of involvement, and detailed slit-lamp examination of the anterior segment. Visual acuity was recorded using Snellen’s chart, and fluorescein staining was performed to identify epithelial corneal lesions. Lacrimal syringing was carried out whenever indicated. Routine laboratory investigations, including complete blood count, random blood sugar, HIV, and hepatitis B surface antigen testing, were performed as part of the clinical evaluation. Microbiological investigations comprised conjunctival and corneal scrapings subjected to Giemsa staining for the detection of multinucleated giant cells suggestive of herpes simplex virus infection. Based on clinical examination, the type of corneal lesion was documented as superficial punctate keratitis, dendritic keratitis, superficial punctate keratitis with dendritic lesions, or stromal keratitis. The corneal layer involved was categorised as epithelial or stromal. Information regarding triggering factors and recurrence was also recorded whenever present. The collected data were entered into Microsoft Excel and analysed using SPSS software. Continuous variables, such as age, were summarized using mean and standard deviation, while categorical variables, including age group, gender, place of residence, laterality, presenting symptoms, corneal lesion morphology, and corneal layer involved, were expressed as frequencies and percentages. As the study was descriptive in nature, the findings were presented using appropriate descriptive statistical methods.

The majority of patients were aged 10–20 years (34.7%), followed by those aged 21–30 years (26.4%), with a mean age of 37.63 ± 13.20 years. Males constituted a slightly higher proportion (54.2%) than females (45.8%). Most participants were from urban areas (87.5%), whereas only 12.5% belonged to rural areas, indicating that viral keratitis was more commonly encountered among urban residents attending the tertiary care centre. (Table 1) Table 1: Baseline demographic characteristics of patients with viral keratitis (N = 72) Variable Categories n % Age group 10 to 20 years 25 34.7 21 to 30 years 19 26.4 31 to 40 years 13 18.1 41 to 50 years 8 11.1 51 to 60 years 5 6.9 >60 years 2 2.8 Gender Male 39 54.2 Female 33 45.8 Place of residence Urban 63 87.5 Rural 9 12.5 Unilateral involvement was more common, accounting for 62.5% of cases, while bilateral disease was observed in 37.5%. Redness was the most frequent presenting symptom (68.1%), followed by diminution of vision (50.0%). Pain (6.9%) and watering (5.6%) were comparatively uncommon clinical complaints. (Table 2) Table 2: Clinical presentation of patients with viral keratitis (N = 72) Variable Categories n % Laterality Unilateral 45 62.5 Bilateral 27 37.5 Presenting symptoms* Redness 49 68.1 Diminution of vision 36 50.0 Pain 5 6.9 Watering 4 5.6 *Multiple presenting symptoms may have been reported by the same patientSuperficial punctate keratitis was the most common lesion pattern, observed in 50.0% of patients. Stromal keratitis accounted for 27.8%, while combined superficial punctate keratitis with dendritic lesions was present in 19.4%. Isolated dendritic lesions were comparatively uncommon and occurred in only 2.8% of patients. (Figure 1) Epithelial involvement was the predominant pattern, accounting for 72.2% of patients, whereas stromal involvement was observed in 27.8%. These findings indicate that viral keratitis more commonly affected the corneal epithelium than the stroma in the study population. (Figure 2).

Given the limited region-specific data on the clinical spectrum of viral keratitis, this prospective observational study was conducted from October 2015 to September 2016 at A.J. Institute of Medical Sciences, Mangalore. After ethics approval and written consent, 72 patients with clinically diagnosed viral keratitis were enrolled by convenience sampling. Demographic and clinical details were recorded, followed by visual acuity testing, slit-lamp examination, fluorescein staining, lacrimal syringing when indicated, routine laboratory tests, and Giemsa staining of corneal or conjunctival scrapings. Lesions were classified by morphology and corneal layer involved. The present study demonstrated a comparatively young cohort, with a mean age of 37.63 ± 13.20 years; 34.7% (n=25) were aged 10–20 years and 26.4% (n=19) were aged 21–30 years. Similar findings were reported by Latha KST et al.5 (2019), with 55.0% aged 0–20 years, Sinha A et al.6 (2017), with 62.5% aged 20–40 years and 33.75% in the 21–30-year group, Jaffar TT et al.7 (2016) (mean age 36.2 years), and Sodani P et al.8 (2022) (mean age 38.61 years; 79.53% aged 21–50 years). In contrast, Shrestha P et al.9 (2023) reported a mean age of 47.19 ± 19.14 years with 22.3% aged 41–50 years, Yousuf M et al.10 (2018) found the highest proportion in the 30–40-year group (36.0%, n=72), and Al Karam M et al.11 (2026) reported a median age of 48.0 years (HSV-1: 52.2 years; VZV: 55.0 years). A slight male predominance (54.2% vs. 45.8%) was consistent with Sinha A et al.6 (2017), Yousuf M et al.10 (2018), Latha KST et al.5 (2019), and Al Karam M et al.11 (2026), whereas Jaffar TT et al.7 (2016) reported equal gender distribution and Shrestha P et al.9 (2023) reported female predominance (60.71%). Urban residents constituted 87.5% (n=63) of the cohort, contrasting with the predominantly agricultural population reported by Sodani P et al.8 (2022), while Yousuf M et al.10 (2018) noted occurrence across both urban and rural populations. Unilateral involvement was observed in 62.5% (n=45) of patients, while 37.5% (n=27) had bilateral disease. Previous studies reported considerably lower bilateral involvement, including Sinha A et al.6 (2017) (25.0%), Jaffar TT et al.7 (2016) (13.6%), Latha KST et al.5 (2019) (12.0%), Shrestha P et al.9 (2023) (3.6%, n=4), and Al Karam M et al.11 (2026) (0.07%, 2/2,892). Yousuf M et al.10 (2018) reported 60.0% right-eye and 40.0% left-eye involvement, with no bilateral cases, indicating that the bilateral involvement observed in the present study was comparatively high. Redness was the commonest presenting symptom (68.1%, n=49), followed by diminution of vision (50.0%, n=36), whereas pain (6.9%, n=5) and watering (5.6%, n=4) were infrequent. Similar predominance of redness was reported by Sodani P et al.8 (2022) (83.04%), Shrestha P et al.9 (2023) (80.35%, n=90), and Jaffar TT et al.7 (2016) (75.0%). Visual impairment was also commonly reported by Shrestha P et al.9 (2023) (47.32%, n=53), Jaffar TT et al.7 (2016) (65.9%), and Sodani P et al.8 (2022) (80–90% in stromal/endotheliitis cases). In contrast, Jaffar TT et al.7 (2016) (52.3% pain), Shrestha P et al.9 (2023) (39.28% watering; 19.6% pain), Sodani P et al.8 (2022) (81.01% pain; 77.92% watering), and Latha KST et al.5 (2019) (photophobia and watering as predominant symptoms) reported substantially higher frequencies of pain and watering than the present study. Superficial punctate keratitis was the most common lesion in the present study, affecting 50.0% of patients (n=36). This was followed by stromal keratitis in 27.8% (n=20), superficial punctate keratitis with dendritic lesions in 19.4% (n=14), and isolated dendritic lesions in 2.8% (n=2). Sinha A et al.6 (2017) similarly reported superficial punctate keratitis in 42.0% of eyes, stromal keratitis in 23.0%, and isolated dendritic lesions in 11.0%. Sodani P et al.8 (2022) observed subepithelial infiltration in 35.22% (n=81) and stromal keratitis without ulceration in 16.52% (n=38), while Jaffar TT et al.7 (2016) reported epithelial and stromal keratitis equally in 38.6% each. Conversely, Yousuf M et al.10 (2018) found dendritic ulcers in 61.5% (n=123), stromal keratitis in 28.0% (n=56), and geographic ulcers in 10.5% (n=21). Latha KST et al.5 (2019) reported dendritic lesions as the commonest presentation at approximately 39%–42%, while superficial punctate keratitis occurred in 13.0%. Shrestha P et al.9 (2023) reported predominantly stromal-associated disease, including pure stromal keratitis in 33.92% (n=38), epithelial-plus-stromal involvement in 16.94% (n=19), stromal keratitis with endotheliitis in 9.81% (n=11), dendritic ulcers in 22.31% (n=25), and geographic ulcers in 11.60% (n=13). Thus, unlike studies in which dendritic or stromal lesions predominated, the present study demonstrated a substantial burden of superficial punctate keratitis, similar to findings reported by Sinha A et al.6 (2017). Epithelial involvement predominated in the present study, accounting for 72.2% of patients (n=52), whereas stromal involvement occurred in 27.8% (n=20). Sinha A et al.6 (2017) similarly reported epithelial keratitis in 60.0% and stromal keratitis in 23.0%. Yousuf M et al.10 (2018) observed epithelial disease, comprising dendritic and geographic ulcers, in 72.0% (n=144), compared with stromal keratitis in 28.0% (n=56), an almost identical distribution. Sodani P et al.8 (2022) reported epithelial keratitis in 43.04% and subepithelial infiltration in 35.22%, together accounting for 78.26%, while stromal keratitis without ulceration occurred in 16.52%. In contrast, Jaffar TT et al.7 (2016) reported equal epithelial and stromal involvement of 38.6% each. Shrestha P et al.9 (2023) demonstrated greater deep corneal disease, including pure stromal involvement in 33.92%, epithelial-plus-stromal involvement in 16.94%, and stromal keratitis with endotheliitis in 9.81%. Overall, the present findings support the predominance of epithelial disease in viral keratitis, while also demonstrating that the distribution of deeper stromal involvement varies across geographical regions, referral settings, and study populations. Strengths and Limitations The strengths of this study include its prospective design, standardized clinical evaluation of all patients, and comprehensive assessment of the demographic profile, clinical presentation, lesion morphology, and corneal layer involvement, providing a detailed description of the spectrum of viral keratitis encountered at a tertiary care centre. However, the study has certain limitations, including a relatively small sample size (72 patients), convenience sampling, single-centre design, and reliance predominantly on clinical diagnosis without routine virological confirmation, which may limit the generalizability of the findings and preclude assessment of the etiological distribution and long-term clinical outcomes.

The study characterized the demographic and clinical spectrum of viral keratitis among 72 patients. It predominantly affected younger individuals, males, urban residents, and one eye. Redness and diminution of vision were the principal presenting symptoms. Superficial punctate keratitis was the most frequent lesion, followed by stromal keratitis, while isolated dendritic lesions were uncommon. Epithelial involvement markedly predominated over stromal disease. Thus, the study successfully described the distribution, presenting features, lesion patterns, and corneal layers affected in viral keratitis. Acknowledgement: We sincerely thank the faculty of the institute for helping us in each aspect of the study. Funding: None Conflict of interest: None declared Ethical approval: The study was approved by the Institutional Ethics Committee.

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