This study was conducted with the aim of determining the VRQoL status and its related factors among the elderly of Yazd city. The prevalence of VI in older adults was 27.8%, the most common of which were hyperopia, cataract and myopia, respectively. The prevalence of VI in the study of Man REK et al., [19] was 26.3%, and in the study of Vignesh et al., [30], 24.5% including cataract (50.7%), uncorrected refractive errors (36.8%) and In the Dev study [31], 60.7% were estimated, which included cataracts (9.8%), corneal opacity (8.33%), glaucoma (7.0%), macular scar (6.73%), retinal degeneration and dystrophy (5.41%). The results of Johansson et al.'s study [25] showed that the most common eye disorders among the elderly included cataracts (23.4%), age-related macular degeneration (4.7%), glaucoma (4.3%) and diabetic retinopathy (1.4%). The prevalence of VI and their types in the present study is almost similar to other studies. Since many eye problems appear with old age and when patients realize their disease that whom vision decreases [1], the results of most studies confirm the above issue. Most of these disorders are common due to changes caused by aging or due to a disease such as diabetes. Also, the main causes of age-related visual impairment in the world include cataracts, macular degeneration, glaucoma, and diabetic retinopathy, but their distribution is slightly different in different countries [32].
The results showed that the studied elderly have a good VRQoL level. In some studies, VRQoL has been reported as moderate [12, 33–36], in some studies similar to the present study as well [20, 24, 25, 37, 38] and in some studies as poor [19]. Since VI increase with age and affect the quality and performance of people's vision, and the majority of the elderly studied were in the age group of 60–70 years, so their quality of life was better. Considering the relationship between VI and poor quality of life, since the prevalence of VI in the elderly was low, this itself can be a reason for their better quality of life. Other reasons for this variation in the results can be the difference in the lifestyle of the elderly, underlying diseases such as diabetes and hypertension, economic status, health care system and cultural values.
Based on the findings of the present study, the dimensions of vision specific social functioning, driving and color vision were favorable, but general health and general vision were not suitable. Although the participants have assessed the vision of both their eyes as generally inadequate, which seems normal, because with age and age-related changes, the power of vision decreases, but in different dimensions, such as seeing the reaction of people about the things said and the occurrence of problems in meeting people at home, parties or restaurants did not have much problem. The results of the present study are consistent with the study of Tavasoli et al. [36], Bigdeli et al. [39], Wu et al. [40], and Wolfram et al. [41]. In general, the elderly tend to present their health status as unfavorable and complain about the conditions and way of life, and for this reason, in the dimension of general health, which is mainly asked with one question, they express their status as unfavorable, which is also the case in other studies [36, 40, 42].
According to the findings of the present study, VRQoL was higher in the age group of 60–69 years and in married elderly people, but no significant relationship was observed between the VRQoL score and gender, education level, having insurance and type of employment. Since aging is one of the risk factors for causing eye problems and diseases, and the elderly are the most vulnerable group for VI, therefore, there is a significant relationship between increasing age and decreasing VRQoL, and this relationship seems logical. Due to the fact that the majority of the participants in this study were literate, had insurance and were retired, therefore, their quality of life scores did not have a statistically significant difference based on the above variables. Regarding gender, since there is no structural or genetic and biological difference between women and men in eyes, in addition, other factors such as education level and occupation were not significantly related to VRQoL, so, there was no significant difference between the quality of life of elderly men and women. The results of the previous studies are different, as in some studies quality of life was related to age, gender, occupation and education [12, 24, 25, 29, 43, 44] and in some studies, these relationships were not significant [20, 36, 45]. Therefore, wider investigations in this field seem necessary.
VRQoL was higher in the elderly who did not use glasses for all tasks. It is obvious that not using glasses to do all the work indicates that the severity of vision problems and disorders is not to the extent that the elderly are forced to use glasses to do all their work and few of them to do things like driving, studying and watching TV had to wear glasses, and therefore VRQoL is favorable and better in them.
VRQoL was poor in elderly people with VI. This finding has been obtained in most studies conducted in the field of VRQoL (14, 20, 46–48). Many people with VI, complain about loss of independence and decrease in emotional well-being and social relationships [49]. VI leads to limitations in all areas of life, especially VRQOL, by reducing activities related to participation in society and religious practices, mobility, recreation, daily life, and visual tasks [31]. In addition, VI is associated with depression, despair and anxiety not only because of the defect but also because of the worry of worsening the condition or difficulty in adapting to reduced activity, and therefore it is possible that with reduced visual acuity, performing daily life activities may be disturbed and as a result affects the social and economic status, increasing dependence and ultimately poor well-being leading to weakening of VRQoL [50].
VRQoL was lower in the elderly with heart disease, diabetes, depression, sleep problems, kidney disease, high blood pressure, and headache. In the study of Crews et al., elderly people with cardiovascular diseases, diabetes and stroke had a poorer quality of life [51]. Co-occurrence of several chronic diseases can affect the VRQoL score [52]. The effect of coexistence on quality of life can be different from the additive effects of concurrent diseases. Social and economic factors undoubtedly affect the relationship between chronic diseases and quality of life, and this relationship refers to health inequalities among social and economic groups [53].
Based on multivariate analysis, the most important predictors of VRQOL were found to be suffering from diabetes and hypertension diseases as well as VI. VI has been identified as an important predictor of VRQOL in various studies [25, 31, 45]. Diabetes and high blood pressure diseases have always been identified as underlying diseases of VI, so it can be said that the key to improving VRQOL and, as a result, the general QoL of the elderly is the prevention of VI. Because VI reduces activities related to participation in society and religious practices, mobility, recreation, daily life, and visual tasks, leading to limitations in all areas of life, especially VRQOL (31).