|Ahead of print publication
Etiology of corneal blindness in patients attending a tertiary care center in Kashmir
Afshan Kounser, Aalia Rasool, Junaid S Wani, Nadia Manzoor
Department of Ophthalmology, Government Medical College, Srinagar, Jammu and Kashmir, India
|Date of Submission||29-Oct-2021|
|Date of Acceptance||05-Jan-2022|
|Date of Web Publication||13-Apr-2022|
Department of Ophthalmology, Government Medical College, Srinagar, Jammu and Kashmir
Source of Support: None, Conflict of Interest: None
PURPOSE: To study the etiology of corneal blindness in patients attending the cornea clinic of a tertiary care center of Kashmir.
MATERIALS AND METHODS: This was a hospital-based cross-sectional study with prospective as well as retrospective recruitment of cases conducted over a period of 2 years. Patients with corneal blindness were included, and history regarding age, gender, laterality, residence, and occupation was taken.
RESULTS: A total of 318 patients were studied with 151 (47.5%) males and 167 (52.5%) females; majority (48.8%) belonged to the age group of 31 to 50 years. 92.8% had unilateral and 7.2% had bilateral involvement, 57.2% belonged to rural and 42.8% to urban areas, and 61% were outdoor and 39% were indoor workers. The most common cause was infectious keratitis (57.54%) which included viral (25.8%), bacterial (23.27%), and fungal (8.5%). Bullous keratopathy accounted for 17.30% (aphakic 3.10% and pseudophakic 14.2%), followed by trauma 10.26% with mechanical trauma 6.29% and chemical trauma 3.46%. Advanced keratoconus accounted for 7.5% of cases and failed graft for 4.72%. Corneal dystrophies and degenerations accounted for 1.9% of cases.
CONCLUSION: Majority of the causes of corneal blindness are preventable if addressed appropriately and timely with good health-care facilities at community level, education, awareness, and proper facilities, especially provision of protective tools and equipment at workplaces.
Keywords: Bullous keratopathy, corneal blindness, infectious keratitis, Kashmir
|How to cite this URL:|
Kounser A, Rasool A, Wani JS, Manzoor N. Etiology of corneal blindness in patients attending a tertiary care center in Kashmir. Taiwan J Ophthalmol [Epub ahead of print] [cited 2022 Sep 28]. Available from: https://www.e-tjo.org/preprintarticle.asp?id=343145
| Introduction|| |
Corneal disorders have become the second most common cause of blindness in developing countries like India.,, It has been reported that India has the world's largest corneal blind population, i.e., the prevalence of corneal blindness in India is 0.45%. The spectrum of infectious keratitis varies with geographical location and is affected by the local climatic conditions and occupational risk factors. Corneal blindness due to microbial keratitis has been more commonly recorded in the rural population, especially in those belonging to the lower socioeconomic strata and those who have no access to education and have poor knowledge about proper eye care.
Some studies done in India are shown in [Table 1] and [Table 2].
| Materials and Methods|| |
The study was a hospital-based cross-sectional study with prospective as well as retrospective recruitment of cases conducted over a period of 2 years (Approval No.: ECGMC/ICM/189). After taking consent, data were collected from the patients attending the Cornea Clinic of Postgraduate Department of Ophthalmology at SMHS Hospital, Government Medical College, Srinagar. Patients with diminution of vision (vision ≤3/60 to positive perception of light [PL]) due to corneal cause were included, and the exclusion criteria were vision >3/60 and no PL and diminution of vision due to other ocular diseases associated with corneal cause.
A detailed clinical history was taken, and data regarding age, gender, laterality, residence, and occupation were taken. A careful anterior segment evaluation with slit lamp was done, and corneal scrapings were taken whenever needed and sent for microbiology. Posterior segment pathologies were excluded B-scan. Examination under anesthesia in pediatric patients was done wherever needed.
Statistical analysis was done using Epi Info. Continuous variables were summarized as mean and standard deviation. Categorical variables were summarized as frequency and percentage. P < 0.05 was considered statistically significant.
| Results|| |
The patients were divided into three age groups:
The first group included patients of 2 years to 30 years which consisted of 43 patients, and the most predominant etiology was infectious keratitis (42%) [Table 3]. The second most common cause was keratoconus (28%), followed by trauma (23%), and other etiologies included pseudophakic bullous keratopathy (4.6%) and sclerocornea (2.3%).
The second group consisted of 155 patients in the age group of 31 to 50 years, and the most predominant etiology was found to be infectious keratitis (59%) which includes viral keratitis (41.3%), bacterial keratitis (39%), and fungal keratitis (19.5%). The second common cause was pseudophakic bullous keratopathy (10.3%), followed by failed graft (8.3%), trauma (7.7%), keratoconus (7.7%), dystrophies (2.6%), degenerations (1.3%), and others (1.3%).
The third group consisted of 120 patients in the age group of 51 to 75 years, and the most predominant etiology was found to be infectious keratitis (60.8%) which includes viral keratitis (45.2%), bacterial keratitis (45.2%), and fungal keratitis (9.5%). The second common cause was pseudophakic bullous keratopathy (22.5%), followed by trauma (8.3%), aphakic bullous keratopathy (6.6%), and failed graft (1.6%).
Two hundred and ninety-five patients (92.8%) had unilateral corneal involvement, among which 158 (53.5%) were females and 137 (46.5%) were males; 23 patients (7.2%) had bilateral involvement, among which 9 (39%) were females and 14 (61%) were males [Table 4].
Out of 151 males, 73 had infectious etiology which included 40 with viral keratitis, 30 with bacterial, and 3 with fungal keratitis. Twenty had trauma, 34 had bullous keratopathy, 12 had failed graft, and the rest had other etiologies, for example, keratoconus, degenerations, and dystrophies [Table 5].
[Table 5] shows Out of 167 females, 88 had infectious etiology which included 42 with viral keratitis, 44 with bacterial, and 24 with fungal keratitis. Twelve had trauma, 32 had bullous keratopathy, 14 had advanced keratoconus, and the rest had other etiologies, for example, failed graft, degenerations, and dystrophies.
57.2% of people belonged to rural areas and the rest 42.8% belonged to urban areas [Table 6].
One hundred and ninety-four (61%) people were outdoor workers (farmers, laborers, welders, carpenters, etc.) and the rest 124 (39%) were indoor workers (shopkeepers, officers, teachers, students, housewives, etc.) [Table 7].
Overall, the most common cause of blindness turned out to be infectious keratitis (57.54%), in which viral keratitis accounts for 25.80%, bacterial keratitis 23.27%, and fungal keratitis 8.50%. Bullous keratopathy accounted for 17.30% (aphakic 3.10%, pseudophakic 14.20%), followed by trauma 10.26%, in which mechanical trauma accounted for 6.29% and chemical trauma, etc., accounted for 3.46%. Advanced keratoconus accounted for 7.60%, of which 4.4% of cases were unilateral and 3.14% had bilateral advanced keratoconus. 4.72% presented with failed graft. Corneal dystrophies and degenerations accounted for 1.90% of cases.
| Discussion|| |
In all the three age groups, the most common etiology of corneal blindness was infectious keratitis which may be attributed to various factors such as residence, geographic location, occupation, economic status, and education. Keratoconus was more in younger age group which may be attributed to the increased prevalence of vernal keratoconjunctivitis and other allergic eye diseases common in younger age group and their positive association with keratoconus. Corneal blindness due to bullous keratopathy was more in elderly patients who had undergone cataract surgery in early times, and during those times, cataract extraction along with intraocular lens implantation was relatively a newer technique, but now due to the advent of newer microsurgical techniques, use of viscosurgical devices, and improved training programs, the outcome has improved and thus reducing the incidence of surgical bullous keratopathy which is evident from the decreased percentage of the same in the younger age group.
Most of the findings were consistent with various studies, for example, Dandona et al. where they found that in childhood and early adulthood, the common cause of corneal blindness was keratitis and trauma. Fathima found that infective keratitis was common in the age group of 40–70 years and trauma and chemical injuries in the age group of 20–40 years. Nangalia and Nigwekar found that corneal blindness was common in the age group of 30–60 years and the predominant cause was infectious keratitis. Veladanda et al. found that corneal blindness was mostly due to infections and trauma in the age group of 40–60 years.
Two hundred and ninety-five patients (92.8%) had unilateral corneal involvement, among which 158 (53.5%) were females and 137 (46.5%) were males; 23 patients (7.2%) had bilateral involvement, among which 9 (39%) were females and 14 (61%) were males. In a study by Dube, the prevalence of corneal blindness was lower among males (1.3%) than females (1.7%). In a study conducted by Patel et al., 52% of females had corneal blindness which is consistent with our study. The higher prevalence among females is attributed to the fact that females perform activities such as gardening, agricultural work, and household activities, which makes them susceptible to injuries and infections, and females residing in rural areas are less likely to seek medical advice due to lack of education and awareness.
Our observation that unilateral corneal blindness is more common than bilateral is consistent with studies by Devi unilateral (85.5%), Veladanda et al., Nangalia and Nigwekar (72%), and Fathima (2019) (86%).
57.2% of people belonged to rural areas and 42.8% belonged to urban areas, which is consistent with a study conducted by Devi, in which corneal blindness is more common in rural areas (rural 83.9% and urban 16.1%). Corneal blindness was common in poorer rural areas in a study by Dandona et al., which is consistent with our study. In our study, corneal blindness due to trauma and infections is more common in rural population which may be attributed to the lack of awareness and education as well as lack of good health-care facility at the local level. In addition, rural population is engaged more in agricultural activities, which again predisposes them to trauma and infections.
One hundred and ninety-four (61%) people were outdoor workers (farmers, laborers, welders, carpenters, etc.) and the rest 124 (39%) were indoor workers (shopkeepers, officers, teachers, students, housewives, etc.). In a study by Fathima, 70% of outdoor workers (farmers) had infectious etiology as compared to indoor workers. Outdoor workers had infectious and traumatic etiology in a greater percentage as compared to indoor workers. Lakra et al. found that only farmers (outdoor workers) were contributing to 47% of corneal blindness and industrial workers contributed to 27% of cases. The predominance of outdoor workers having corneal blindness can be justified by the fact that in Kashmir, the majority of the activities that may be causing corneal trauma and susceptibility to infections, for example, agricultural activities, industrial works, welding, carpentry, and masonry, are carried out by outdoor workers mainly consisting of the male population. In addition, safety provisions, for example, use of protective goggles and proper washing facilities, at workplaces are not so common.
The most common etiology for corneal blindness in our study was found to be infectious keratitis (57.54%) which included viral keratitis 25.8%, bacterial keratitis 23.27%, and fungal keratitis 8.5%. Infectious etiology as the most common cause of blindness was found in numerous studies, for example, a study by Tandon et al. (62.5%), Sony et al. (28.38%), Devi (42.25%), and Nangalia and Nigwekar (27%). Dandona and Dandona also found infectious keratitis among the leading causes in South Indian population. Feng found herpes simplex keratitis (viral keratitis) as a leading cause (42.8%) followed by bacterial keratitis (17.4%), which is consistent with our study. In our study, the prevalence of viral keratitis more than bacterial or fungal keratitis can be explained by the observation that Kashmir having relatively less temperature than most of the states provides favorable climatic conditions for viral growth and progression, especially herpes group of viruses.
In our study, surgical bullous keratopathy accounted for 17.30% (aphakic 3.10% and pseudophakic 14.2%). There is a variable distribution of bullous keratopathy, which is evident from studies conducted by Tandon et al. (8.9%), Veladanda et al. (5.5%), Pinnita Prabhasawat et al. (27.8%), and Sony P et al. (13.45%), which is almost consistent with our study.
Corneal blindness following trauma was found in 10.26% of patients (mechanical trauma 6.29% and chemical trauma, etc., 3.46%). Krishnaiah et al. found that 10.6% of patients had traumatic corneal blindness, which is consistent with our study. Similarly corneal blindness following trauma was found by Atti et al. in 37% cases, Veladanda et al. in 59.3%, Dandona et al. in 23.2% and H Nagpal in 13.33% similar to the finding in our study. Trauma was common among male population than female population which may be attributed to the occupation. Advanced keratoconus accounted for 7.5%, of which 4.4% of cases were unilateral and 3.14% had bilateral advanced keratoconus. Nangalia and Nigwekar found keratoconus in 1%. Corneal dystrophies and degenerations accounted for 1.9% of cases, but a study conducted by Atti et al. showed that 15% of patients had dystrophies and degenerations, 0.3% had sclerocornea, and miscellaneous consisted of 0.6%.
- Three hundred and eighteen patients with corneal blindness were studied, among which 167 were females and 151 were males
- Two hundred and ninety-five patients had unilateral corneal blindness and 23 had bilateral blindness
- Infectious keratitis, trauma, and bullous keratopathy were the leading causes of corneal blindness
- People of rural areas were more common in our study than urban areas
- People engaged in outdoor activities in day-to-day life were more susceptible than those engaged in indoor activities
- Male gender was most predominantly having corneal blindness owing to their day-to-day outdoor activities than female counterparts
- Adult population, mostly people in the working-age group, were more susceptible than children or elderly population.
| Conclusion|| |
Corneal blindness has become an important cause of blindness in this part of the world. The study of corneal blindness becomes important as it is preventable and curable to a large extent and preventive measures prove to be the most cost-effective means of decreasing the global burden of corneal blindness.
Financial support and sponsorship
Conflicts of interest
The authors declare that there are no conflicts of interests of this paper.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]