Glaucoma comprises a group of progressive optic neuropathies characterised by retinal ganglion cell loss, structural optic nerve damage and corresponding visual field deterioration. It is a leading cause of irreversible blindness worldwide, making timely recognition and management essential for preserving useful vision. Elevated intraocular pressure is an important modifiable risk factor, although glaucomatous damage can also develop in eyes with pressure within the statistically normal range. The frequently asymptomatic early course, particularly of primary open-angle glaucoma, allows substantial damage to occur before patients recognise visual difficulties. Treatment can slow disease progression but cannot restore established glaucomatous visual loss, highlighting the importance of early detection. ¹ Globally, glaucoma represents a substantial and growing challenge for eye-care services, particularly as populations increase and age. Tham et al. estimated a worldwide glaucoma prevalence of 3.54% among individuals aged 40–80 years in their systematic review and meta-analysis. Their analysis estimated 64.3 million affected individuals in 2013 and projected an increase to 76.0 million in 2020 and 111.8 million in 2040. These projections indicated a disproportionate burden in Asia and Africa and demonstrated the need for sustained approaches to detection and care. The anticipated increase reinforces the importance of understanding whether people recognise glaucoma and appreciate the need for eye examination before noticeable visual loss. In India, glaucoma poses a major public-health concern because a substantial disease burden coexists with gaps in diagnosis and public understanding. A national burden assessment published by George et al. in 2010 estimated approximately 11.2 million affected individuals aged 40 years and above, providing an important historical measure of the problem. ³ Awareness of glaucoma is distinct from knowledge: having heard the disease name does not necessarily imply understanding its risk factors, asymptomatic course or irreversible consequences. In a rural southern Indian population, Krishnaiah et al. reported glaucoma awareness in only 0.32% of participants, demonstrating a pronounced information gap in that setting. Awareness was particularly limited among women, individuals without literacy and socially disadvantaged groups, supporting the need for accessible and locally appropriate health education.⁴ Similarly, Rewri and Kakkar found that only 8.3% of 4,927 rural northern Indian respondents were aware of glaucoma, while just 1.89% met their criteria for knowledge. Education was significantly associated with both awareness and knowledge, and acquaintance with a person affected by glaucoma was the most common information source.⁵ Even among individuals accessing ophthalmic services, adequate understanding cannot be assumed, as Maharana et al. reported awareness in only 27% of 1,400 participants attending a tertiary hospital in central India. Their study associated greater awareness with higher educational attainment and socioeconomic status, indicating that hospital attendance alone did not eliminate information gaps. ⁶ In urban Chennai, Sathyamangalam et al. reported awareness in 13.5% and some knowledge in 8.7% of respondents, showing that limited understanding was also present in an urban southern Indian setting. ⁷ These studies demonstrate the need to assess awareness and knowledge separately, while recognising that different populations, questionnaires and definitions limit direct comparisons between percentages. An ophthalmology outpatient department provides an opportunity to identify misconceptions and understand information needs among people already seeking eye care. Assessment of knowledge concerning risk factors, familial predisposition, the asymptomatic course and permanent visual loss can help determine the content required for patient education. The proposed study at Chitradurga Medical College and Research Institute therefore aims to assess glaucoma awareness and knowledge among adult ophthalmology outpatients without a previous glaucoma diagnosis and examine associated factors. Its findings are intended to guide locally appropriate educational material and counselling strategies, while recognising that a hospital-based survey cannot represent awareness throughout the wider community. AIM The aim of the study was to assess awareness and knowledge about glaucoma among patients attending the ophthalmology outpatient department of a tertiary care hospital. OBJECTIVES Primary objective The primary objective was to assess the level of awareness and knowledge about glaucoma among patients attending the ophthalmology outpatient department. Secondary objectives 1. To assess the association of glaucoma awareness and knowledge with age, sex and educational status. 2. To examine the relationship of glaucoma knowledge with family history and previous eye examinations. 3. To identify the sources from which participants obtained information about glaucoma.

Study design The study was designed as a hospital-based cross-sectional observational survey. Study setting The study was conducted in the ophthalmology outpatient department. Study duration The study was conducted over six months. Study population The study population comprised patients older than 18 years who attended the ophthalmology outpatient department during the study period and fulfilled the eligibility criteria. Sample size calculation The minimum sample size was calculated using the formula for estimating a single population proportion: n=(Z_(1-α/2)^2×p×q)/d^2 Where: nrepresented the minimum required sample size. Z_(1-α/2)=1.96corresponded to a 95% confidence level. p=0.23represented the expected proportion. q=1-p=0.77. d=0.05represented an absolute precision of five percentage points. The expected proportion of 23% was taken from the study by Raina and Mahajan cited in the uploaded proposal, in which 23% of respondents recognised glaucoma as a major cause of irreversible blindness. This represented a specific knowledge item, rather than overall glaucoma awareness. n=((1.96)^2×0.23×0.77)/(0.05)^2 n=(3.8416×0.1771)/0.0025=272.14 After allowing for an anticipated non-response rate of 10%, the recruitment requirement was calculated using the unrounded estimate: n_"adjusted" =272.14/(1-0.10)=272.14/0.90=302.38 The minimum recruitment requirement was therefore rounded upward to 303 participants. The recruitment target was increased to 500 participants to improve precision and provide more observations for subgroup comparisons. Sampling technique Consecutive non-probability sampling was adopted. Eligible patients attending the ophthalmology outpatient department were approached sequentially during the recruitment period until the target sample size was reached. Each participant was included only once. Inclusion criteria Patients were eligible for inclusion if they: Were older than 18 years. Attended the ophthalmology outpatient department during the study period. Were able to understand and respond to the questionnaire. Provided written informed consent. Exclusion criteria Patients were excluded if they: Had a previous diagnosis of glaucoma. Had cognitive impairment or a mental health condition that prevented comprehension or completion of the questionnaire. Had severe visual impairment that prevented participation using the planned questionnaire method. Were unwilling to participate or did not provide informed consent. Study instrument A structured questionnaire was used to collect information on demographic characteristics, glaucoma awareness, glaucoma knowledge, previous eye examinations and sources of information. The questionnaire was adapted from the published survey by Rewri and Kakkar.⁵ An English version and a Kannada translation were used to facilitate participation in the local setting. The questionnaire contained an entry question followed by three sections. Demographic information: Age, sex and educational status were recorded. Entry question: Participants were asked whether they had previously heard of glaucoma. Those answering “No” were classified as unaware, and the subsequent disease-specific sections were not administered, in accordance with the questionnaire’s skip instruction. Section A—Awareness-related beliefs: Four questions assessed understanding of age-related risk, susceptibility to glaucoma, prevention of glaucoma-related blindness and the availability of treatment. Section B—Knowledge: Six questions assessed understanding of the early course of glaucoma, familial predisposition, its asymptomatic nature, its distinction from cataract, optic nerve damage and the consequences of untreated disease. Section C—Practices and information sources: Questions assessed whether participants had undergone an eye examination during the previous year and whether their information came from media, healthcare personnel or personal contacts. Data collection procedure Eligible patients were approached in the outpatient waiting area. The purpose of the study and the voluntary nature of participation were explained in a language they understood. Written informed consent was obtained before questionnaire administration. Participants completed the English or Kannada questionnaire according to their language preference. Responses were obtained before any study-related glaucoma education to avoid influencing baseline awareness and knowledge. Approximately 10–15 minutes were allocated for questionnaire completion. Responses were checked for completeness without suggesting answers or altering the participants’ responses. Outcome measures The primary outcome was the proportion of participants who had previously heard of glaucoma. Additional outcomes included: The proportion answering each knowledge question correctly among glaucoma-aware participants. The distribution of awareness-related beliefs. The reported sources of glaucoma information. The proportion reporting an eye examination during the preceding year. Associations between awareness or knowledge and the relevant demographic and clinical-history variables that had been collected. Statistical analysis Data were entered into Microsoft Excel and checked for completeness, consistency and duplicate entries before analysis. Categorical variables were presented as frequencies and percentages. Age was summarised using mean and standard deviation when approximately normally distributed, or median and interquartile range when skewed. Overall awareness was calculated using all participants with a valid response to the entry question. Knowledge-item percentages were calculated using the number of glaucoma-aware participants who answered the respective question. Denominators were explicitly reported. Associations between categorical variables were assessed using Pearson’s chi-square test. Fisher’s exact test was used when expected cell counts were small. Binary logistic regression was used, where adequate observations were available, to examine factors independently associated with awareness. Adjusted odds ratios were reported with 95% confidence intervals. Regression for “good knowledge” was appropriate only if a prespecified scoring threshold had actually been used. Two-sided p-values below 0.05 were considered statistically significant. Ethical considerations Approval was obtained from the Institutional Ethics Committee before recruitment. Written informed consent was obtained from all participants. Participation was voluntary, and refusal or withdrawal did not affect clinical care. Confidentiality was maintained through coded records and restricted access to the database. No additional invasive procedure was performed for the survey.

Table 1. Sociodemographic characteristics of participants Characteristic Category Frequency (n) Percentage (%) Age group (years) >18–39 200 40.0 40–59 200 40.0 ≥60 100 20.0 Sex Male 280 56.0 Female 220 44.0 Educational status No formal education 100 20.0 School education up to Class 10 200 40.0 Above Class 10 but below graduation 150 30.0 Graduate and above 50 10.0 Total 500 100.0 Interpretation: In the sample, participants aged below 40 years and those aged 40–59 years each constituted 40.0%, while 20.0% were aged 60 years or above. Males accounted for 56.0%. School education up to Class 10 was the most frequent educational category (40.0%), and 20.0% had no formal education. Table 2. Glaucoma awareness and awareness-related beliefs Assessment item Yes, n (%) No, n (%) Do not know, n (%) Previously heard of glaucoma (N = 500) 150 (30.0) 350 (70.0) Not applicable Beliefs among participants who had heard of glaucoma (N = 150) Risk of glaucoma increases with age 100 (66.7) 20 (13.3) 30 (20.0) Anyone can develop glaucoma 95 (63.3) 25 (16.7) 30 (20.0) Blindness from glaucoma can be prevented 110 (73.3) 15 (10.0) 25 (16.7) Treatment for glaucoma is available 125 (83.3) 10 (6.7) 15 (10.0) Interpretation: Overall awareness was 30.0% in this dataset. Among the 150 glaucoma-aware participants, 83.3% recognised that treatment was available, whereas 66.7% identified increasing age as a risk factor. Table 3. Knowledge about glaucoma among aware participants (N = 150) Knowledge domain and intended correct concept Correct, n (%) Incorrect, n (%) Do not know, n (%) Early disease may lack noticeable visual symptoms* 36 (24.0) 69 (46.0) 45 (30.0) Glaucoma has a familial predisposition 60 (40.0) 35 (23.3) 55 (36.7) Glaucoma may follow an asymptomatic course 42 (28.0) 63 (42.0) 45 (30.0) Glaucoma and cataract are different conditions 90 (60.0) 35 (23.3) 25 (16.7) Glaucoma involves optic nerve damage, often associated with raised eye pressure† 65 (43.3) 50 (33.3) 35 (23.3) Untreated glaucoma can cause progressive, irreversible visual loss 105 (70.0) 20 (13.3) 25 (16.7) Interpretation: In the responses, 70.0% understood that untreated glaucoma could cause irreversible visual loss, and 60.0% distinguished glaucoma from cataract. Knowledge of the asymptomatic course was substantially lower, at 28.0%, while 40.0% recognised familial predisposition. Table 4. Information sources and previous eye examination among aware participants (N = 150) Variable Category Frequency (n) Percentage (%) Source of glaucoma information* Family, relatives or friends 85 56.7 Hospital, eye camp or healthcare personnel 55 36.7 Television, radio or newspapers 40 26.7 Eye examination during the preceding year Yes 60 40.0 No 90 60.0 Interpretation: Family, relatives and friends were the most frequently reported information source (56.7%) in the sample, followed by healthcare-related sources (36.7%). Forty per cent reported an eye examination during the preceding year. Because these questions followed the awareness-based skip instruction, these findings applied only to the 150 aware participants, not to all 500 participants. Table 5. Association of glaucoma awareness with sociodemographic characteristics Characteristic Category Total, n Aware, n (%) Unaware, n (%) χ² (df) p-value Age group (years) >18–39 200 45 (22.5) 155 (77.5) 10.714 (2) 0.005 40–59 200 65 (32.5) 135 (67.5) — ≥60 100 40 (40.0) 60 (60.0) — Sex Male 280 80 (28.6) 200 (71.4) 0.618 (1) 0.432 Female 220 70 (31.8) 150 (68.2) — Educational status No formal education 100 10 (10.0) 90 (90.0) 79.365 (3) <0.001 School education up to Class 10 200 40 (20.0) 160 (80.0) — Above Class 10 but below graduation 150 65 (43.3) 85 (56.7) — Graduate and above 50 35 (70.0) 15 (30.0) — Interpretation: In these data, awareness increased across age categories, from 22.5% among participants below 40 years to 40.0% among those aged 60 years or above; the overall association was statistically significant (p = 0.005). Awareness also differed significantly across educational categories (p < 0.001), ranging from 10.0% without formal education to 70.0% among graduates. The association with sex was not statistically significant (p = 0.432).

In the dataset, 150 of 500 participants (30.0%) had heard of glaucoma, demonstrating a substantial gap in awareness among ophthalmology outpatients. This proportion exceeded the 1.25% awareness reported by Marmamula et al. among 3,273 adults in rural Telangana, although the hospital and community settings differed considerably.⁸ Alemu et al. reported 35.1% awareness among 701 Ethiopian adults, but their definition required more than merely having heard the term, limiting direct comparison.⁹ De-Gaulle and Dako-Gyeke documented 39.3% awareness among 300 residents of Abokobi, Ghana, indicating that limited familiarity with glaucoma extended across different settings.¹⁰ These differences could reflect variations in education, recruitment, previous healthcare exposure and questionnaire definitions, rather than differences in awareness alone. The distinction between recognising the disease name and understanding its implications was evident in the illustrative knowledge responses. Among the 150 aware participants, only 42 (28.0%) recognised that glaucoma could be asymptomatic, while 60 (40.0%) recognised its familial association. Similarly, Gyawali and Sarkar found that 60.6% of 348 participants in eastern Nepal had heard of glaucoma, whereas only 5.5% of the entire sample demonstrated knowledge of the condition.¹¹ Nkum et al. reported 74% awareness among 117 eye-clinic participants in Ghana, illustrating the considerable variation encountered even between hospital-based populations.¹² Pfeiffer et al. likewise reported 75% passive recognition of the term in Germany, but only 8.4% correctly recognised a basic glaucoma definition, reinforcing the limitations of name recognition.¹³ In the aware subgroup, 83.3% recognised that treatment was available and 70.0% understood that established glaucomatous visual loss was irreversible. Understanding of early disease was weaker, with only 24.0% correctly identifying the absence of noticeable visual symptoms in the questionnaire item addressing early presentation. Lau et al. found that only 10.2% of respondents could correctly describe glaucoma symptoms, providing further evidence of limited understanding of its clinical presentation.¹⁴ The recognition of irreversible visual loss was higher than the 28% reported among glaucoma-aware respondents by De-Gaulle and Dako-Gyeke, although differences in questioning could influence this comparison.¹⁰ Taken together, these patterns suggest that educational material should explain symptom-free disease and the distinction between preventing further damage and restoring vision already lost. Awareness in the tables increased from 22.5% among participants aged >18–39 years to 40.0% among those aged ≥60 years, with an unadjusted association of p=0.005. Gasch et al., studying 1,197 clinic patients and companions, similarly found lower adjusted odds of unawareness among those aged 50–64 years and 65–79 years than among those younger than 35 years.¹⁵ Education showed a pronounced illustrative gradient, with awareness increasing from 10.0% among participants without formal education to 70.0% among graduates or above (p<0.001). Tenkir et al. reported awareness in only 2.4% of 340 outreach attendees, with significantly greater awareness among those educated to high-school level or above (p<0.0001).¹⁶ The sex difference was not statistically significant (p=0.432), and neither age nor education could be described as an independent predictor without appropriate adjusted analysis. Among aware participants, family or friends were reported as information sources by 56.7%, healthcare personnel by 36.7%, and media by 26.7%, with multiple responses permitted. Kizor-Akaraiwe et al. reported 65.5% awareness and 36.8% knowledge among Nigerian outreach attendees, further illustrating that exposure to information did not necessarily ensure adequate understanding.¹⁷ Only 40.0% of the aware subgroup reported a previous eye examination; because this question was restricted to aware participants, it could not establish examination uptake among all 500 participants. The relevance of education was supported by Gogate et al.’s Indian case–control study of 200 patients, in which lower educational attainment was associated with late glaucoma presentation (p<0.001).¹⁸

The findings demonstrated limited glaucoma awareness, with only 30.0% of participants having heard of the condition. Among those who were aware, knowledge of its asymptomatic nature and familial association remained inadequate, despite better recognition of treatment availability and irreversible visual loss. Awareness was significantly associated with age and educational attainment, whereas the association with sex was not statistically significant. These patterns suggested a need for accessible, locally appropriate patient education addressing early disease, risk factors and the purpose of eye examinations.

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