Impact of Visual Impairment and Blindness on Quality of Life of Patients in Owerri, Imo State, Nigeria.

PURPOSE: This study sought to determine the quality of life (QOL) of patients with visual impairment in Federal Medical Centre, Owerri, Imo State, with a view to making recommendations for comprehensive management of patients.
MATERIALS AND METHODS: This was a hospital-based, cross-sectional study carried out at the Eye Clinic of Federal Medical Centre, Owerri, Imo State, Southeast Nigeria. New patients aged 18 years and older were consecutively recruited. Data were obtained using a semi-structured questionnaire and a World Health Organization's QOL Scale-Short Form (WHO-QOL-BREF). Participants had comprehensive eye examinations, and data were analyzed using the Statistical Package for the Social Sciences version 22.
RESULTS: One hundred and eight (53.7%) females and 93 (46.3%) males with a mean age of 55.92 ± 16.94 years participated in the study. The major causes of visual impairment were uncorrected refractive error, glaucoma, and cataract. Glaucoma (6.5%) was the leading cause of blindness. The overall QOL score was 61.10 ± 19.75, with the lowest mean score in the environmental domain. With increasing visual impairment, there was a 19.1% reduction in QOL. QOL was also affected by age, duration of visual impairment, and history of poor near vision.
CONCLUSION: The leading causes of visual impairment and blindness in this study are avoidable and treatable. Health education, appropriate intervention, and support groups should be encouraged. This may serve to reduce the burden of visual impairment and improve the QOL of patients. Copyright:

Introduction

According to the World Health Organization (WHO) in 2012, the number of people visually impaired was estimated to be 285 million.[1] Of these, 246 million had low vision, while an estimated 39 million were blind.[1] Sixty-three per cent of those with low vision and 82% of blind people were over 50 years, and about 90% live in low-income countries.[23] Twenty-eight per cent of people living with moderate and severe visual impairment were within the working-age group.[4] This may affect their ability to find employment, support themselves, and provide for their families.[4] This is largely because many of the activities that define independence and productivity in society require good vision, and one of the most devastating consequences of advancing visual impairment is a progressive loss of independence.[56]

In Nigeria, the prevalence of low vision and blindness was 3.4% and 6.1%, respectively, and as life expectancy has increased from 37 years at independence to 50 years, the number of adults with visual impairment is expected to increase.[78]

In assessing the impact of visual impairment, the American Medical Association's guide estimated that the loss of one eye is equivalent to 25% impairment of the visual system and 24% impairment of the whole person, while total loss of vision in both eyes is considered to have 100% visual effects on physical, psychological, mental, and emotional well-being of a person.[9] This is a reflection of what portends for a society with a high prevalence of visual impairment. The impact will affect not only the individual but also the family, the caregivers, and the community, leading to a significant cost burden.[10]

Quality of life (QOL) is the standard of health, comfort, and happiness experienced by an individual. It is perceived as the individual's ability to enjoy normal life activities and consists of a range of subjective and objective aspects.[1112] In a study done in Germany, a significant relationship was reported between increasing severity of ocular diseases which cause visual impairment and reduction in QOL.[13] The Blue Mountain Eye Study also reported that severe noncorrectable visual impairment was associated with significantly poorer short form-36 scores.[14] In addition, they noted that the impact was directly related to its severity regardless of the underlying condition. Other international-based studies also noted that poor vision reduced the QOL and caused a decrease in most domains of health-related QOL scores.[513]

In Nigeria, poor QOL has also been reported in people with severe visual impairment and this was associated with reduced functioning and social interaction.[612] Significant reduction in QOL was also noted in patients with glaucoma with a clear trend of worsening QOL scores, with increasing severity of disease.[6] Improvement in the QOL should, therefore, become a major goal in the provision of health care.

This study aims to determine the impact of visual impairment on QOL of the participants with a view to making recommendations for a more encompassing wholesome care of visually impaired patients.

Materials and Methods

This was a cross-sectional descriptive study in which new patients with visual impairment were recruited randomly between July 2016 and January 2017. This study was conducted according to the guidelines of the Declaration of Helsinki.

Ethical clearance was obtained from the Ethics and Research Committee of Federal Medical Centre, Owerri, while written informed consent was obtained from the participants.

A sample size of the participants with visual impairment was determined using the formula.

Where

N = Minimum sample size.

Z = The standard normal deviate, usually set at 1.96 corresponding to 95% confidence interval.

p = Assumed prevalence taken from the estimated prevalence of visual impairment which is 6.27% (0.0627).[12]

q = 1.0 − p (1.0 − 0.0627) = 0.9373.

d = Precision level acceptable = 5% (0.05).

This gave a minimum sample size of approximately 97. However, a sample size of 201 was used in this study.

Data collection and analysis

A semi-structured closed-end questionnaire was used to collect information on the demographic details of the participants. In addition, the WHO-QOL-BREF was used to assess QOL.[15] The latter is a 26-item questionnaire consisting of four domains: physical (items 3, 4, 10, 15, 16, 17, and 18), psychological (items 5, 6, 7, 11, 19, and 26), social (items 20, 21, and 22), and environmental (items 8, 9, 12, 13, 14, 23, 24, and 25). This assessment tool has been used in various studies in Nigeria.[1216] The questionnaire was rated on a 5-point scale ranging from “not at all” (score of 1) through to “completely” (score of 5). Higher scores indicated a better QOL. The scores of these four domains were combined to produce a total score for QOL.

Visual acuity test was performed for each eye separately using the Snellen's chart or illiterate E-chart placed 6 m from the participant. For those participants with bilateral involvement, the visual acuity was determined by the worst eye.

Refraction was performed on participants whose visual acuity improved with pinhole.

Participants in this study with reduced QOL scores were referred for psychotherapy.

Data were analyzed using the Statistical Package for the Social Science version 22 (IBM Software Group, Chicago, IL, USA). Means of continuous variables were compared using Student's t-test and ANOVA. Statistical significance was set at P < 0.05 for all analyses.

Results

A total of one hundred and eight females (53.7%) and ninety three males (46.3%) were recruited for this study [Table 1]. One hundred and twenty five participants (62.1%) were 40 years and above. About 69 (34.3%) participants had tertiary level of education.

Table 1

Sociodemographic characteristics of participants

Variables	Study group, n (%)
Age group
<20	16 (7.9)
20-29	27 (13.4)
30-39	33 (16.4)
40-49	40 (19.9)
50-59	40 (19.9)
≥60	45 (22.3)
Sex
Male	93 (46.3)
Female	108 (53.7)
Marital status
Single	20 (9.9)
Married	143 (71.1)
Separated	9 (4.5)
Divorced	3 (1.5)
Widowed	26 (13.0)
Educational level
No formal	37 (18.4)
Primary	46 (22.9)
Secondary	49 (24.4)
Tertiary	69 (34.3)
Occupation
Professional	38 (18.9)
Skilled worker	32 (16.0)
Unskilled worker	65 (32.3)
Student	9 (4.5)
Unemployed	57 (28.3)

The overall mean QOL scores of the participants were 61.10. The physical domain had an overall mean score of 70.93, while the psychological, social, and environmental domains had overall mean scores of 69.61, 68.07, and 64.79, respectively.

The QOL mean scores was significantly affected by education and employment; being lowest in the uneducated and unemployed (P < 0.05). Marital status showed no significant difference in the QOL mean scores.

Majority (35.3%) of the participants had mild visual impairment, 28.7% had moderate visual impairment, 20% had severe visual impairment, and 15.9% were blind. The most common causes of visual impairment and blindness noted were uncorrected refractive error (73%) followed by cataract (53%) and then glaucoma (37%). Glaucoma, however, was the most common cause of blindness followed by cataract, while cataract was the most common cause of severe visual impairment.

Mean QOL score decreased as severity of illness increased, being highest in mild and worst among the blind, and this was statistically significant (F = 11.42, P < 0.0001) [Table 2].

Table 2

Quality of life with respect to visual impairment

Visual impairment	Mean	95% CI		F	P
		Lower	Upper
Mild	72.17	67.57	76.78	11.42	<0.0001
Moderate	62.41	57.79	67.04
Severe	62.00	57.47	66.53
Blindness	49.38	41.19	57.56

CI: Confidence interval

There is a significant negative correlation between QOL and visual impairment [Table 3]. Approximately 19.1% drop in QOL is accounted for by visual impairment and this is statistically significant (P = 0.007).

Table 3

Correlation between visual impairment and quality of life

Variable	QoL
	ρ	P
Visual impairment	−0.191	0.007

Rho Spearmen correlation coefficient. QoL: Quality of Life

Maximum difference in QOL was observed between mild visual impairment and blindness. However, there is no significant difference in QOL between moderate and severe visual impairment [Table 4].

Table 4

Mean difference in quality of life

Category	Visual impairment	Mean difference	P	95% CI
				Lower	Upper
Mild	Blindness	22.81	<0.0001	12.57	33.03
	Moderate	9.76	0.02	1.24	18.28
	Severe	10.17	0.03	0.67	19.68
Blindness	Mild	−22.81	<0.0001	−33.03	−12.57
	Moderate	−13.04	0.01	−23.57	−2.50
	Severe	−12.62	0.02	−23.97	−1.28
Moderate	Mild	−9.76	0.02	−18.28	−1.24
	Blindness	13.04	0.01	2.50	23.57
	Severe	0.41	0.97*	−9.42	10.25

*Not significant. CI: Confidence interval

The participants who were blind had the lowest QOL domain score with the lowest seen in the environmental domain (54.92). Those with mild impairment had the highest scores in all the domains [Table 5].

Table 5

Effect of visual impairment on quality of life domain

Domains	Mild	Moderate	Severe	Blind	F	P
Physical	77.56	71.79	69.46	58.21	34.37	<0.001*
Psychological	76.72	68.51	67.67	58.75	45.62	<0.001*
Social	73.62	66.78	63.67	63.96	13.46	<0.001*
Environmental	71.19	64.27	62.38	54.92	39.05	<0.001*

*Statistically significant. F: F statistics test using ANOVA

QOL domain mean scores were significantly lower in the physical domain in participants who had visual impairment >1 year (t = 2.549, P = 0.012). However, no significant difference was found in other domains (P > 0.05) [Table 6].

Table 6

Effect of duration on quality of life

	Duration of visual impairment		t	P
	≤1 year	>1 year
Physical	74.51	69.26	2.54	0.012*
Psychological	71.75	68.63	1.79	0.074
Social	70.58	66.91	1.74	0.082
Environmental	65.71	64.36	0.91	0.364
QoL	61.90	64.41	0.82	0.409

*Statistically significant. t: Student’s t-test, QoL: Quality of life

Table 7 shows that there was a significant mean difference in all QOL domains, with respect to self-reported history of poor near vision (P < 0.05).

Table 7

Effect of near vision on quality of life domains

	History of poor near vision		F	P
	Yes	No
Physical	72.29	78.39	4.470	<0.001*
Psychological	71.05	76.41	4.455	<0.001*
Social	67.93	74.74	4.779	<0.001*
Environment	65.55	68.18	2.520	0.012*

*Statistically significant. t: Student’s t-test

Participants with uncorrected refractive error had significantly higher QOL mean scores in all the domains compared to subjects that had cataract and glaucoma (P < 0.05) [Table 8 and Figure 1].

Table 8

Effect of ocular diseases on quality of life domain

	Cataract	Glaucoma	URE	ANOVA	P
Physical	66.28	65.71	79.03	18.17	<0.001*
Psychological	67.50	63.64	75.73	16.08	<0.001*
Social	66.40	66.03	70.93	3.98	0.002*
Environment	63.06	61.19	69.20	9.56	<0.001*

*Statistically significant. URE: Uncorrected refractive error

Figure 1

Line graph showing effect of ocular diseases on quality of life. URE: Uncorrected refractive error

Patients with glaucoma had the lowest QOL domain mean scores compared to other diseases.

Discussion

The mean age in this study was 55.92 ± 16.94 years. Majority of the participants were 40 years and older (62.2%), and more females than males were visually impaired, contrary to other studies.[17] An increased risk of visual impairment with age has been reported in some studies.[1718]

Most of the participants in this study had a high level of education (58.7%). Being educated is usually associated with better jobs, higher income, and increased chances of taking up health-care services. The Nigerian Visual Impairment Survey reported that illiteracy was strongly associated with blindness and visual impairment.[7]

Of the 201 visually impaired participants in this study, 35.3% had mild visual impairment, 48.7% had low vision, and 15.9% were blind. The leading causes of visual impairment in this study were uncorrected refractive errors (36.3%), cataract (26.4%), and glaucoma (18.4%), similar to other studies.[19] In contrast, a hospital-based retrospective study reported cataract (36.5%), glaucoma (20.1%), and refractive errors (19.3%) as the common causes of visual impairment.[20] The latter however excluded patients with mild visual impairment from their study, and this may have contributed to the low frequency of refractive error. A community-based study also in Imo state reported uncorrected refractive error (31.6%), glaucoma (23.5%), and cataract (12.5%) as the leading causes of visual impairment.[21] These differences can be attributed to the study type: clinic based versus community based. Nevertheless, uncorrected refractive error is still the most common cause of visual impairment and a major cause of low vision followed by cataract similar to previous hospital-based studies.[1819]

As demonstrated in this study, there was a significant decrease in QOL scores among the participants with increasing severity. Previous studies also documented similar results.[1217] Here, we observed a significant mean difference between mild visual impairment and blindness (22.81), which was statistically significant. Visual impairment accounted for 19.1% reduction in QOL. Increasing severity of visual impairment may lead to more burden on the family or care giver. This is consistent with findings from previous studies and has implications for daily living.[13]

The index study showed that participants who were visually impaired from uncorrected refractive error had better QOL than those with cataract and glaucoma in that order. The permanence of visual loss from glaucoma, especially when advanced may be responsible for this result.

Bilateral blindness was significantly associated with reduction in all the QOL domains compared to those with monocular blindness. Patients with bilateral blindness may have higher levels of emotional instability and reduced ability to adequately cater for themselves. This disability makes one totally dependent on family.

Assessing the different domains of QOL, the environmental domain (64.79 ± 9.78) was mostly affected similar to other studies.[1617] In this study, the environmental domain of the blind (54.92) was mostly affected. Finance and limited opportunity for leisure were the major problems noted by the participants. Having an income of < 5000 Naira (14 US dollars)/month has been associated with poor QOL.[12] With the recent inflation in the country, N5000/month is grossly insufficient to cater for health needs and daily upkeep.

The social domain was greatly affected by the respondents' lack of satisfaction with their sex life. This may be attributed to our culture as most elderly people may find it difficult to have intimate relationships with their spouses as they get older. However, most of them were satisfied with the support they got from their family and friends, similar to the study among older persons in Thailand.[22] While this result highlights the importance of the African culture of family support, there is also need to develop focal support groups for people with visual impairment and their relations so as to help reduce the effect of vision loss. Health educators and eye caregivers have a role to play in this area.

Participants with visual impairment reported having negative feelings. This study also demonstrated that the mean scores of the psychological domain decreased as the severity of visual impairment increased. This may be due to the psychological trauma that is associated with the uncertainties of visual loss. Similar studies have shown positive relationships between visual impairment and depression.[1723] Evans et al. also reported a significant association between increasing severity of visual impairment and depression.[24] In this index study, 41 patients were referred to psychotherapy. This may improve QOL.

Regarding the physical domain, majority of the participants reported dissatisfaction in the ability to perform daily living activities and the capacity to work. Individuals are less likely to enjoy their work if they have difficulty doing the work and appreciating a good outcome. The tendency may be to ignore the activities and its frustrations.

Self-reported poor near vision was also associated with significant reduction in the physical, psychological, and social domains similar to other studies.[1617]

The duration of visual impairment significantly affected the physical domain (P = 0.012). However, the QOL mean score was lower among participants with ≤1 year duration. This may be due to initial anxiety and uncertainty associated with a new diagnosis, which later diminishes as the individual adapts to living with the ailment. In contrast, Briesen et al.[25] reported that longer duration of visual impairment was associated with lower QOL. This disparity may be due to the study tools used. While a generic-specific QOL instrument was used in this study, time trade-off was used as the QOL assessment tool in their study.

This study did not show significant difference between the QOL of participants with comorbidities and those without. This may be due to the fact that most of these patients were already on treatment. Furthermore, the WHO-QOL-BREF is a general questionnaire and not disease specific. Brown et al. also reported no statistically significant difference between the comorbidity and no comorbidity groups in self-assessed QOL.[26] However, van Nispen et al. reported a decline in QOL in patients with coexisting medical condition after a 5-month follow-up. They included participants with irreversible visual loss and debilitating medical conditions such as chronic obstructive pulmonary disease and stroke. This may have contributed to the significant QOL decline reported.[27]

Limitations

A population-based study would have provided a broader insight into the burden of the impact of visual impairment on QOL

QOL scores are largely subjective and may result in high scores for some questions, especially in participants with low vision who may have adapted to their reduced vision.

Conclusion

The major causes of visual impairment based on presenting visual acuity were uncorrected refractive error, glaucoma, and cataract, while glaucoma was the leading cause of blindness. There was an associated reduction in QOL of the participants in all domains, with the lowest mean scores noted in the environmental domain.

Severity, duration of visual impairment, and history of poor near vision also affected the QOL. Living with systemic comorbidities was not significantly associated with reduction in QOL of the participants. Forty-one patients with low QOL were referred for psychotherapy.

Recommendations

QOL should be routinely assessed in patients with visual impairment and appropriate intervention instituted for those with low scores. In addition, there is a need to form support groups for those with similar ocular disorders to encourage rehabilitation through psychotherapy.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.