Ethical consideration

This retrospective study is part of thesis work for the fulfilment of Doctor of Philosophy in Health Studies at the Vietnam National Institute of Malariology, Parasitology and Entomology. This study was conducted in accordance with the principles of the Declaration of Helsinki and obtained clearance from the ethics committee of the institute. Informed consent was waived by the ethics committee due to the retrospective nature of the analysis using information contained in medical charts and records, which were anonymize.

The sample size for this study is determined by the standard formula for estimating a population proportion. With an anticipated proportion (p) of 50% patients being males, at a 95 per cent confidence interval, relative precision (e) of 5% the desired sample size was 1537.^[10] Data of all new subjects with diseases of the eye and adnexa admitted to the Nghe an Eye Hospital, Nghe An province, Vietnam between January 2022 and May 2023 was retrieved. The patients underwent a thorough routine eye examination and were diagnosed with diseases belonging to category VII (Diseases of the eye and adnexa) of the International Statistical Classification of Diseases (ICD-10 Version: 2015).^[11] All the patients received standard care for eye diseases as instructed by the Vietnam Ministry of Health and their length of stay was recorded.

Data analysis was performed using SPSS version 23.0 (IBM Corporation, Armonk, NY, USA). Categorical variables were expressed as case number (n) and percentages, while numerical variables were expressed as mean and standard deviation (±SD). The comparison between numeric variables was done by student T-test and chi-square for categorical variables. For all statistical tests, the decision was significant if the p-value is < 0.05.

Pattern of eye disease

The majority (955, 55.0%) of our sample came for treatment of disorders of sclera, cornea, iris, and ciliary body ([Table 2]) and keratitis was the commonest ocular morbidity (40.1%). The dominance of corneal lesions in the present study follows the trend of more prevalent of keratitis in low-income countries.^[12], ^[13] It is important to note that corneal lesion is the fifth most common cause of blindness and infectious keratitis is the leading cause of corneal blindness worldwide.^[12] For the limited resources in a provincial eye hospital, the specific agents causing corneal ulcers could not be identified. However, about 80% of local people are farmers so they are at a considerable risk of infection keratitis of traumatic aetiology, especially fungal keratitis.^[12] A previous study conducted at Vietnam National Eye Hospital showed that fungi (n=1092, 64.0%) and bacteria (n=1107, 64.9%) were the two most commonly identified pathogens causing infectious keratitis.^[14]

The second most common cause of eye disease among hospital patients is glaucoma (29.2%) which agrees with observations in Ghana,^[5] Bangladesh.^[15] In the present study, disorders of the eyelid, lacrimal system and orbit were less frequent in comparison to the other disorders. In the Thai population, this disorder is the second most common among out-patient eye conditions (13.8%), however, contribute to only 3.3% among in-patient eye conditions.^[3] In England and Wales, the disorders of the eyelid, lacrimal system, and orbit (11.5%) is still the frequent cause of hospitalization for diseases of the eye and adnexa, however, in a decreasing trend.^[4] These results may suggest the difference in the pattern of eye disease among different populations. Some disorders were not included in the analysis due to their rarity such as disorders of vitreous body and globe (H46-H48), of optic nerve and visual pathways (H49-H52) and disorders of ocular muscles, binocular movement, accommodation, and refraction (H53-H54). Disorders of the conjunctiva are common in out-patients, however, they are usually rare among in-patients.^[3] In the present study, all patients with the disorder of conjunctiva also had lesions of the cornea so they were diagnosed with keratoconjunctivitis and analyzed as keratitis.

Age differences

In our sample, more than three-quarters of patients (78.6%) are those aged > 50 years old and the average age was 60.4± 16.5 years ([Table 1]). The predominance of aged participants in the current study replicates those from other studies. Click or tap here to enter text.^[16], ^[17] In Poland, more than 80% of people in the age group above 50 years suffer from eye diseases.^[18]

Considering age group variations, our results are consistent with many previous studies. The preponderance of younger patients with sclera, cornea, iris, and ciliary body disorders in the current study ([Figure 1] and [Table 3]) was in line with other reports in Vietnam,^[14] and elsewhere.^[19], ^[20] In general, corneal lesion is more prevalent among persons of working age.^[12] Conversely, disorders of the eyelid, lacrimal system and orbit and glaucoma seem to be more common among older persons ([Figure 1]). This can be attributed to the ageing population, who are more susceptible to senile ptosis, lacrimal, and orbital disorders.^[4] Glaucoma is a disease characterized by a degeneration of retinal ganglion cells and retinal nerve fiber layers and the relationship between the disease with age has been confirmed in many studies.^[21], ^[22]

Gender differences

Regarding gender variations, data in [Table 1] shows that females (54.7%) were more in attendance than males at our hospital. This agrees with some previous studies in Ghana,^[5] Sudan,^[16] and Nigeria.^[17] The significant disproportion of ocular disease among women has been affirmed in many clinically based studies, however, the knowledge of this disparity is limited.^[23]

Concerning the difference in gender among different type of disease, results in [Figure 2] show that male/female differences in groups 2 and 3 were similar to all sample, but in group 1, the proportion of women was significantly higher. Our finding was consistent with results of a study done in England and Wales which found a higher rate of admission due to disorders of eyelid, lacrimal system, and orbit among women.^[4]

Length of stay

Results in [Table 4] show that most patients were at the hospital for three or four days and keratitis had the longest average length of hospital stay. This finding agrees with a previous studies performed among the Thai population which shows that the longest hospital stay is among patients with keratitis.^[3] With the highest prevalence and longest hospital stay of keratitis, measures to prevent this disorder may have great significance in reducing both morbidity and health expenditures for eye disease among the local population.

There are some limitations of our study. This is a hospital-based study, so it is unable to accurately assess the pattern of eye diseases in the general population. In addition, due to the retrospective nature of the study, other factors that may predict the length of hospital stay can not be identified.