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Prevalences and causes of vision
impairment in elderly Chinese: a socioeconomic perspective of a comparative
report nested in Jiangsu Eye Study
Rong-Rong
Zhu, Jian Shi, Mei Yang, Huai-Jin Guan
Eye Institute,
Affiliated Hospital of Nantong University, Nantong 226001, Jiangsu Province,
China
Correspondence to: Huai-Jin Guan. Eye Institute,
Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001,
Jiangsu Province, China. guanhjeye@126.com
Received: 2015-07-24
Accepted: 2015-11-19
Abstract
AIM: To survey the prevalence and
causes of visual impairment/blindness among elderly Chinese from different
socioeconomic status in community-based design.
METHODS: Cluster-sampling randomly
selected residents from Binhu and Funing
District, two areas representing different socioeconomic levels in China with
Binhu in an advanced status and Funing in less-developed area. The participants
subjected to ophthalmic examination. The presenting visual acuity (PVA) and
best-corrected visual acuity (BCVA) were recorded. Visual impairment and
blindness were defined according to World Health Organization criteria. The
causes of visual impairment/blindness were identified by ophthalmic examination
and/or questionnaire. The socioeconomic status included the per capita gross
domestic product, numbers of hospital with ophthalmic service and the number of
ophthalmologists per 1 million residents.
RESULTS: We successfully included 12 867
participants form 2 areas in this study. The prevalence of PVA impairment
(<20/63 to ≥20/400) in the better eye was 5.4% in Binhu and 23.6% in Funing,
while the prevalence of blindness (<20/400) was 0.9% in Binhu and 2.3% in
Funing. With BCVA, the prevalence of visual impairment was 2.4% in Binhu and
6.4% in Funing, while the prevalence of blindness was 0.8% in Binhu and 1.6% in
Funing. The participants with older age and female gender had higher prevalence
in visual impairment and blindness. The highest prevalences of vision
impairment and blindness evaluated by BCVA at >80y age group reached 20.4%
and 6.3% respectively. The prevalences of vision impairment and blindness
evaluated by BCVA were 3.5% and 1.0% in male and 5.0% and 1.3% in female. The
above differences were statistically significant (P<0.05). The predominant causes of visual impairment and
blindness were cataract, retinal disorders and uncorrected refractive error in
both areas. The socioeconomic status was associated with visual impairment and
blindness.
CONCLUSION: This community-based study build a
sufficient sample size for an ophthalmic survey. Our data show the disparities on
socioeconomic development and genders in visual impairment and blindness
in China. Special emphasis of ophthalmic service should be placed on females
and less-developed area.
KEYWORDS: blindness; vision impairment; prevalence;
community-based; socioeconomic
development
DOI:10.18240/ijo.2016.07.19
Citation: Zhu RR, Shi J, Yang M, Guan HJ. Prevalences
and causes of vision impairment in elderly Chinese: a socioeconomic perspective
of a comparative report nested in Jiangsu Eye Study. Int J Ophthalmol
2016;9(7):1051-1056
INTRODUCTION
Visual impairment is recognized as a major public health problem
worldwide. A global initiative, VISION 2020-The Right to Sight, was launched in
1999 by the World Health Organization (WHO) with an aim to eliminate avoidable
blindness by 2020[1]. In
2002, WHO estimated that there were 161 million people with visual impairment
and approximately 37 million were legally blind. Over 90% of the visually
impaired people live in developing countries. China, with a population of 1.3
billion accounting for 15% of the world’s population, is estimated the
prevalence of blindness in people ≥50y as 2.3% as reported in 2004[2]. In consistence with
this estimation, a large scale of ophthalmic survey conducted in 2006-2007
reported the prevalence of blindness of 2.29% among older adults in rural China[3].
During past 20y, there were numerous ophthalmic surveys conducted in China[4-11], including similar
studies in our Jiangsu province[12-15]. Despite steady growth of
China’s economy, there are increasing regional disparity in socio-economic
development. We hypothesize that this disparity might also impact the profile
of residents’ vision health and the data of previous studies on vision health
might not reflect the real picture of nowadays. Southern Jiangsu and northern Jiangsu has obvious
differences in socioeconomic development. In this study, we selected Binhu
in southern and Funing in northern Jiangsu as the sampling areas and collected
the data with the focus on the prevalence and causes of visual
impairment/blindness among adults ≥50 years of age.
SUBJECTS AND METHODS
A total of 12 867 persons aged ≥50y from the two areas were enumerated and
a total of 12 053 (93.8%) participants with vision acuity (VA) data were
collected (Table 1). The two areas represented different economic levels in
Jiangsu Province with the per capita Gross domestic product (GDP) in Binhu
nearly 4.5 times higher than that in Funing District, The government of Binhu
invested more resources in medical service including more hospitals with eye
departments and more eye-doctors (Table 2).
Table
1 Study population by area
n (%)
|
Areas |
Geographical
location |
GDP
(hundred million, ￥) |
Total
Population |
Real
GDP Per capita (￥) |
Enumerated |
Examined |
Examination
response rate (%) |
|
Binhu |
South |
492.5 |
689 000 |
84 000 |
6722 (52.2) |
6106 (35.5) |
90.8 |
|
Funing |
North |
198.0 |
1 090 000 |
18 662 |
6145 (47.8) |
5947 (34.6) |
96.8 |
GDP: Gross domestic product.
Table
2 Resources of ophthalmic service by area
|
Areas |
Hospitals with ophthalmic service |
Ophthalmologists |
Ophthalmologists per 1 million residences |
|
Binhu |
11 |
35 |
50.8 |
|
Funing |
5 |
21 |
19.3 |
The survey followed the protocol of a national study on vision health[3]. We randomly selected
individuals according to the sampling frames constructed using geographically
defined clusters based on district and village register data. Cluster
boundaries were defined that each cluster would have a population of
approximately 1000 individuals (all ages).
Sample size was based on an anticipated 4% prevalence for visual
impairment <20/200 within an error bound (precision) of 20% with 95%
confidence[4-5]. Assuming
an examination response rate of 90%, and a design effect of 1.5 to account for
inefficiencies associated with the cluster sampling design, a sample of 5315
persons ≥50 years of age was required for each area. Depending on the
percentage of population ≥50 years of age, 28 clusters were randomly selected
(with equal probability) from the sampling frame in Binhu and 30 clusters in
Funing. Three clusters were selected for preliminary experiment. Geographically
defined cluster sampling included 6722 individuals aged ≥50 years in Binhu
district from January to December 2010. Actually 6106 persons were examined
with the response rate of 90.8%. The same sampling was used in 6145 randomly
selected individuals aged ≥50y in Funing from September 2010 to May 2011 and
actually 5947 individuals were examined with the response rate of 96.8%.
The list of residents ≥50 years of age were obtained from the residence
registers, followed by door-to-door household visits conducted by local
government staff or community doctors. Those ≥50 years of age were enumerated
by name, gender and age. Individuals temporarily absent at the time of the
household visit were included in the enumeration. Unregistered adults ≥50 years
of age were enumerated and included in the study sample if they had been living
in the household for ≥6mo.
Study participants were examined at the community clinics or local
government buildings. The trained health workers administered a standard
questionnaire to collect details of demographic information, general medical
history and ophthalmic history. All the responding subjects had their blood
pressure and blood glucose measured, and then underwent ophthalmic
examinations. Those who did not appear at the examination site were revisited
by a member of the enumeration team to encourage participation. The physically
disabled and those failing to come to the examination site after repeated
contact were offered an ocular examination at their homes.
Distance VA was measured using an Early Treatment Diabetic Retinopathy
Study logMAR E-chart (Precision Vision, Villa Park, IL, USA) with a standard
illumination box. VA measurement began at a distance of 4 m with the top line
(20/200). If the orientation of at least four of the five optotypes was
correctly identified, the subject was then tested by dropping down to line 4
(20/100) line, to line 7 (20/50), to line 10 (20/25), and finally to line 11
(20/20). If the individual failed to identify the top line at 4 m, the subject
was advanced to 2 m and then to 1 m, progressing down the chart as described
above. VA was recorded as the smallest line read with 1 or no errors. Testing
for counting fingers, hand movement, light perception, or no light perception
was checked on those unable to read the top line at 1 m. The VA was measured in
each eye initially without refractive correction or with distance glasses if
the participant routinely worn it. Those presenting with VA ≤20/25 in either
eye were refracted to achieve best corrected VA (BCVA). Subjective refraction
was performed by a trained optometrist for those subjects, and auto
refractometer (AR-610; NIDEK, Japan) readings were used as the starting point
for subjective refraction carried out without pupil dilation. For those in whom
subjective refraction was not performed, particularly the elderly examined at
their homes, BCVA was assumed to be the same as presenting visual acuity (PVA)
if pinhole vision combined with examination findings indicated a principal
cause of impairment other than refractive error as described below.
Ocular examination of the eyelid, globe, pupillary reflex, lens and fundus
was carried out by two study ophthalmologists. For those with
aphakia/pseudophakia, surgical history (year and place) was obtained, with
clinical details pertaining to the type of surgery and surgical complications
noted during the examination. Participants with BCVA ≤20/40 had their pupils
dilated for direct ophthalmoscopy and slit-lamp examination. Intraocular
pressure measurement by applanation tonometry was performed on an optional
basis for glaucoma suspects with optic disc abnormalities. Gonioscopy and
ultrasound biomicroscopy (UBM) at light/dark states were utilized to inspect
early angle-closure glaucoma without clinical symptoms.
Eyes with PVA ≤20/40 were assigned one principal cause of visual
impairment and blindness out of 14 causes including uncorrected refractive
error, amblyopia, cataract, posterior capsule opacification, corneal
opacity/scar, phthisical/disorganized/absent globe, glaucoma, other optic
atrophy, macular degeneration, myopic maculopathy, diabetic retinopathy,
retinal detachment, other retinal/choroidal changes and undetermined cause[3]. Uncorrected refractive
error was assigned as the cause for eyes that were improved to ≥20/32 with
refractive correction, or with pinhole vision when subjective refraction was
not possible. Cataract was assigned when lens opacity was commensurate with
visual impairment and no other abnormality could account for the decreased VA.
Affiliated Hospital of Nantong University Committee on Ethics on Research
approved the implementation of the survey protocol. Informed written consent
was obtained from all study participants. The study adhered to the tenets of
the Declaration of Helsinki.
Statistical Analysis Original forms in hard copies were
transferred to the data management and analysis center at the Affiliated
Hospital of Nantong University. Computerized data entry was carried out using
standardized programs (Epidata 3.0). Statistical analyses were performed using
STATA 10.0 (Stata Statistical Software, Release 10.0, Stata Corp, College
Station, TX, USA). Confidence intervals (CI) and P values of percentage
comparison (significant at the P≤0.05 level) were calculated with
adjustment for clustering effects and stratification associated with the
sampling design.
VA was categorized as normal vision (≥20/32); mild visual impairment (near
normal vision, 20/40 to 20/63); moderate visual impairment (<20/63 to
20/200); severe visual impairment (<20/200 to 20/400); and blindness
(<20/400) in the better eye. Prevalence of moderate and severe visual
impairment (<20/63 to 20/400) and blindness were calculated on the basis of
both PVA and BCVA. The comparison of percentage was performed by χ2 method. Multiple logistic
regressions were used to analyze the correlation of age (using 10-year
categories), gender and area with presenting and best-corrected visual
impairment/blindness. Geographic location was explicitly included as a
regression variable.
RESULTS
The age and gender distribution of the examined population within each
area is shown in Table 3. The distribution of age and genders of study
participants were similar between the two areas.
Table 3 Examined participants within each
area by age and gender n (%)
|
Parameters |
Binhu |
Funing |
Total |
|
Age (a) |
63.4±8.4 |
64.4±8.7 |
63.9±8.5 |
|
50-59 |
2175 (35.6) |
1995 (33.6) |
4170 (34.6) |
|
60-69 |
2590 (42.4) |
2203 (37.0) |
4793 (39.8) |
|
70-79 |
1024 (16.8) |
1464 (24.6) |
2488 (20.6) |
|
≥80 |
317 (5.2) |
285 (4.8) |
602 (5.0) |
|
Gender |
|
|
|
|
M |
2600 (42.6) |
2467 (41.5) |
5067 (42.0) |
|
F |
3506 (57.4) |
3480 (58.5) |
6986 (58.0) |
|
Total |
6106 (100) |
5947 (100) |
12053 (100) |
The Table 4 shows the distribution within each area of PVA and BCVA in the
eye with better VA. As for PVA, the overall prevalence of moderate/severe
visual impairment (≥20/400 to <20/63) was 14.4%, with 5.4% in Binhu and
23.6% in Funing. The overall presenting blindness (<20/400) was 1.6%, with
0.9% in Binhu and 2.3% in Funing. As for BCVA, the overall prevalence of
moderate/severe visual impairment was 4.4%, with 2.4% in Binhu and 6.4% in
Funing. The overall blindness with best correction was 1.1%, with 0.8% in Binhu
and 1.6% in Funing. The proportion above 20/40 for PVA is much higher in Binhu
(76.7%) than in Funing (29.5%), as for BCVA 89.4% in Binhu and 73.1% in Funing,
which suggest higher proportion of uncorrected refractive error in economically
less-developed area.
Table
4 Distribution of PVA and BCVA in the better eye
n
(%; 95%CI)
|
Parameters |
Binhu |
Funing |
||
|
|
BCVA |
PVA |
BCVA |
|
|
VA>20/40 |
4684
(76.7; 75.7-77.8) |
5461
(89.4; 88.7-90.2) |
1756
(29.5; 28.4-30.7) |
4345
(73.1; 71.9-74.2) |
|
20/63≤VA≤20/40 |
1038
(17.0; 16.1-17.9) |
452
(7.4; 6.8-8.1) |
2648
(44.5; 43.3-45.8) |
1127
(19.0; 18.0-20.0) |
|
20/200≤VA<20/63 |
298
(4.9; 4.3-5.4) |
135
(2.2; 1.8-2.6) |
1287
(21.6; 20.6-22.7) |
339
(5.7; 5.1-6.3) |
|
20/400≤VA<20/200 |
30
(0.5; 0.3-0.7) |
12
(0.2; 0.1-0.3)a |
118
(2.0; 1.6-2.3) |
44
(0.7; 0.5-1.0) |
|
VA<20/400 |
56
(0.9; 0.7-1.2) |
46
(0.8; 0.5-1.0) |
138
(2.3; 1.9-2.7) |
92
(1.5; 1.2-1.9) |
CI: Confidence
interval; VA: Visual acuity; PVA:
Presenting visual acuity; BCVA: Best-corrected visual acuity. aConfidence intervals
were calculated using the exact binomial distribution instead of the normal
approximation.
PVA and BCVA (Tables 5 and 6) indicated that visual impairment and
blindness were associated with area, age and gender. In general, the
less-developed area had higher rates of
visual impairment and blindness (Table 5). After adjusted against age and
gender, the difference of the rates of visual impairment and blindness between
the two areas remained (Table 6). The prevalences PVA and BCVA present a steady
increases with age in both areas. The highest prevalences of vision impairment
and blindness evaluated by BCVA at >80 years age group reached 20.4% and
6.3% respectively. The prevalences of vision impairment and blindness evaluated
by BCVA were 3.5% and 1.0% in male and 5.0% and 1.3% in female (Table 6).
Table 5 Presenting and best-corrected
visual impairment (<20/63-20/400) and blindness (<20/400) by area n (%)
|
Parameters |
Binhu |
Funing |
P |
Odds
ratio (95%
CI) |
|
Visual
impairment |
|
|
|
|
|
PVA |
328
(5.4) |
1405
(23.6) |
<0.001 |
2.3
(2.2-2.5) |
|
BCVA |
147
(2.4) |
383
(6.4) |
<0.001 |
1.7
(1.5-1.8) |
|
Blindness |
|
|
|
|
|
PVA |
56 (0.9) |
138
(2.3) |
<0.001 |
1.6
(1.4-1.9) |
|
BCVA |
46 (0.8) |
92 (1.6) |
<0.001 |
1.4
(1.2-1.7) |
CI: Confidence interval; VA: Visual
acuity; PVA: Presenting visual acuity; BCVA: Best-corrected visual acuity.
Table 6 Presenting and best-corrected visual
impairment (<20/63-20/400) and blindness (<20/400) n (%)
|
Parameters |
Visual
impairment |
Blindness |
||||||
|
|
BCVA |
PVA |
BCVA |
|||||
|
Prevalence |
Odds
Ratio (95%
CI) |
Prevalence |
Odds
Ratio (95%
CI) |
Prevalence |
Odds
Ratio (95%
CI) |
Prevalence |
Odds
Ratio (95%
CI) |
|
|
Age
(a) |
|
|
|
|
|
|
|
|
|
50-59 |
246
(5.9) |
Reference |
55 (1.3) |
Reference |
22 (0.5) |
Reference |
12 (0.3) |
Reference |
|
60-69 |
527
(11.0) |
2.2
(1.9-2.6)b |
119
(2.5) |
2.0
(1.5-2.8)b |
51 (1.1) |
2.1
(1.3-3.5)b |
39 (0.8) |
3.0
(1.5-5.8)b |
|
70-79 |
720
(28.9) |
6.9
(5.9-8.1)b |
233
(9.4) |
7.7
(5.7-10.4)b |
76 (3.1) |
5.7
(3.5-9.3)b |
49 (2.0) |
6.9
(3.6-13.1)b |
|
≥80 |
240
(39.8) |
14.8
(11.8-18.6)b |
123
(20.4) |
21.7
(15.5-30.3)b |
45 (7.5) |
16.2
(9.5-27.4)b |
38 (6.3) |
24.7
(12.6-48.3)b |
|
Gender |
|
|
|
|
|
|
|
|
|
M |
607
(12.0) |
Reference |
179
(3.5) |
Reference |
71 (1.4) |
Reference |
49 (1.0) |
Reference |
|
F |
1126
(16.1) |
1.8
(1.6-2.0)b |
351
(5.0) |
1.7
(1.4-2.1)b |
123
(1.8) |
1.4
(1.1-2.0)a |
89 (1.3) |
1.5
(1.1-2.2)a |
|
Area |
|
|
|
|
|
|
|
|
|
Binhu |
328
(5.4) |
Reference |
147
(2.4) |
Reference |
56 (0.9) |
Reference |
46 (0.8) |
Reference |
|
Funing |
1405
(23.6) |
2.4
(2.2-2.6)b,c |
383
(6.4) |
1.6
(1.5-1.8)b,c |
138
(2.3) |
1.6
(1.3-1.8)b,c |
92 (1.6) |
1.4
(1.2-1.7)b,c |
|
Total |
1733
(14.4) |
- |
530
(4.4) |
- |
194
(1.6) |
- |
138
(1.1) |
- |
CI: Confidence interval; VA: Visual
acuity; PVA: Presenting visual acuity; BCVA: Best-corrected visual acuity. aP<0.05;
bP<0.001; cadjusted
for age and gender.
Principal causes of visual impairment and blindness are shown in Table 7.
Cataract was the most common cause for visual impairment and blindness both in
Binhu and Funing. Uncorrected refractive error was the second cause of visual
impairment and blindness according to the PVA in both
areas. Treatable causes of visual impairment accounted for nearly 70% of the
total cases.
Table
7 Principal causes of the loss of presenting visual acuity n (%)
|
Areas |
Principal
cause |
<0.3-0.1 |
<0.1-0.05 |
<0.05 |
Total |
|
Binhu |
Cataract |
332 (37.1) |
38 (36.5) |
146 (42.3) |
516 (38.5) |
|
|
Refractive error |
375 (42.0) |
21 (20.2) |
12 (3.5) |
408 (30.4) |
|
Retina disorders |
79 (8.9) |
24 (23.1) |
53 (15.4) |
156 (11.6) |
|
|
AMD |
63 (7.1) |
18 (17.3) |
35 (10.1) |
116 (8.7) |
|
|
Amblyopia |
24 (2.7) |
7 (6.7) |
9 (2.6) |
40 (3.0) |
|
|
Corneal opacity/scar |
13 (1.5) |
2 (1.9) |
15 (4.3) |
30 (2.2) |
|
|
Optic atrophy |
6 (0.7) |
1 (1.0) |
22 (6.3) |
29 (2.1) |
|
|
Disorganized globe |
0 (0.0) |
0 (0.0) |
25 (7.3) |
25 (1.9) |
|
|
PCO |
11 (1.2) |
3 (2.9) |
9 (2.6) |
23 (1.7) |
|
|
Myopic maculopathy |
6 (0.7) |
3 (2.9) |
13 (3.8) |
22 (1.6) |
|
|
Diabetic retinopathy |
10 (1.1) |
1 (1.0) |
2 (0.6) |
13 (1.0) |
|
|
Glaucoma |
4 (0.5) |
1 (1.0) |
5 (1.5) |
10 (0.8) |
|
|
Retina detachment |
0 (0.0) |
2 (1.9) |
3 (0.9) |
5 (0.3) |
|
|
Other cause |
48 (5.4) |
7 (6.7) |
49 (14.2) |
104 (7.8) |
|
|
Total |
892 (100) |
104 (100) |
345 (100) |
1341 (100) |
|
|
Funing |
Cataract |
1185 (41.1) |
144 (39.0) |
212 (32.6) |
1541 (39.5) |
|
|
Refractive error |
1292 (44.8) |
81 (22.0) |
53 (8.1) |
1426 (36.5) |
|
Retina disorders |
70 (2.4) |
22 (6.0) |
50 (7.7) |
142 (3.6) |
|
|
Corneal opacity/scar |
23 (0.8) |
10 (2.7) |
65 (10.0) |
98 (2.5) |
|
|
AMD |
44 (1.5) |
5 (1.4) |
26 (4.0) |
75 (1.9) |
|
|
Amblyopia |
43 (1.5) |
3 (0.8) |
11 (1.7) |
57 (1.5) |
|
|
Myopic maculopathy |
9 (0.3) |
15 (4.0) |
10 (1.5) |
34 (0.9) |
|
|
Optic atrophy |
11 (0.4) |
3 (0.8) |
19 (2.9) |
33 (0.8) |
|
|
Disorganized globe |
1 (0.0) |
0 (0.0) |
30 (4.6) |
31 (0.8) |
|
|
Diabetic retinopathy |
15 (0.5) |
1 (0.3) |
10 (1.5) |
26 (0.7) |
|
|
PCO |
7 (0.2) |
3 (0.8) |
13 (2.0) |
23 (0.6) |
|
|
Glaucoma |
10 (0.4) |
0 (0.0) |
13 (2.0) |
23 (0.6) |
|
|
Retina detachment |
2 (0.1) |
1 (0.3) |
4 (0.7) |
7 (0.1) |
|
|
Other cause |
244 (8.4) |
103 (27.9) |
185 (28.4) |
532 (13.6) |
|
|
Total |
2886 (100) |
369 (100) |
651 (100) |
3906 (100) |
AMD: Age-related macular degeneration; PCO:
Posterior capsule opacification.
Of the 12053 participants, 357 (2.96%) were with glasses for distance
correction at the time of the examination, with 264 (73.9%) of these presenting
with normal vision (VA>20/40) in one or both eyes. However, if everyone who
was correctable to >20/40 in ≥1 eye with refraction had had glasses, the
overall percentage with normal vision would increase from 53.4% to 81.4%.
DISCUSSION
This survey enumerated a larger number of participants. The response rate
of this survey exceeded 90% that was considered as sufficient, which attributed
to the mandatory training for team members before the survey, repeated
household visits as needed and offering the examinations at home when
necessary. The study is a part of longitudinal cohort named after Jiangsu Eye
Study. We reported here the baseline data that will be very important for the
follow-up of the cohort. The data reflect the current spectrum of common eye
diseases in China and the vision impairment distribution in the regions at
different economic development levels.
This study recorded mild visual impairment (VA 20/40-20/63), which
followed the design of the China Nine-province Survey[3]. The prevalence of mild visual impairment was 17.0%
in Binhu and 44.5% in Funing with presenting vision; and the prevalence in
Binhu was within the range (10.8%-27.4%) reported in the China Nine-province
Survey while the prevalence of Funing was much higher.
Cataract was the most common cause for blindness and visual impairment
based on PVA both in Binhu and Funing, which is consistent with other studies
conducted in China[4-13].
Uncorrected refractive error was the leading cause of visual impairment in
different parts of the world[7,16-19]. Similar to the result from the
China Nine-province Survey[3],
less than 1% of the examined population presented with spectacles for distance
correction in Funing (0.77%). Because most participants in Funning were
farmers, they were not accustomed to wearing glasses and thought it was not
convenient to do their job. In contrast, higher percentage (5.09%) of the
examined population in Binhu presented with spectacles than that in Funing. The
Binhu district locates in the suburb of Wuxi that has 4 tertiary general
hospitals and people in that area can expediently receive eye care. The Funing
County locates in the middle of the north of Jiangsu Province and has big
geospatial distance to major cities where basic eye care can be provided. So as
a result of economic and geospatial factors, the accessibility and the relative
affordability of eye care services is superior in Binhu than within Funing.
This suggests that the lack of eye care and/or inaccessibility among rural
Chinese might contribute to this disparity.
About half of those presenting with moderate/severe and mild vision
impairment improved to normal vision at least in ≥1 eye with BCVA, suggesting
that refractive correction is one of the determinative factors in the outcome
of eye care.
Our survey also provides evidence that visual impairment and blindness is
associated not only with older age, as expected, but also with female gender
and socioeconomic levels of the sampling areas. These findings are consistent
with the 1996 Shunyi survey, 2001 Beijing survey, 2004 Liwan Eye Study 7, 2006 Sichuan survey[10],
2007 Harbin survey[11]
the Nine-Province Survey[3]
in China, 2001 Canada survey[20],
and the Singapore Eye Studies[16,21].
In the absence of information on family income, the situation and per capita
GDP of each area can be considered as a surrogate indicator of socioeconomic
status. Even though the association was solid, we cannot establish a
casual-effect relation between the socioeconomic status and vision outcomes
with the data available.
In conclusion, the present study has added the data of the prevalence of
visual impairment and blindness in the elderly Chinese and established the
baseline data of the Jiangsu Eye Study. As noted, special emphasis in health
policy should be placed on the relatively high prevalence of visual impairment
and blindness among females and on narrowing the disparity between the areas in
different developing levels. Refractive error correction may be an effective
strategy in the intervention.
ACKNOWLEDGEMENTS
The authors are
responsible for the content and writing of the paper. The authors thank all the
participants for their cooperation. We appreciate the great contribution of
Affiliated Wuxi People’s Hospital of Nanjing Medical University, Funing Health
Bureau, Funing County Center for Disease Prevention and Control, Shizhuang Eye
Hospital of Funing and the People’s Hospital of Funing in study coordination
and participant recruitment. The authors thank Jialiang Zhao, MD, Chinese
Academy of Medical Sciences, and Peking Union Medical College Hospital for
scientific advice. The Jiangsu Eye Survey Teams are composed of Wuxi group (Yong Yao, Jing Zhu,
Donghong Fu, Jianchu Sun, Tianhua Xie, Li Yin, Qianqian Yu) and Funing
group (Rongrong
Zhu, Jian Shi, Congkai Liang, Bihong Liu, Hong Jiang, Linjuan Jiang, Jianfeng
Gao, Jian Liu, Dajun Sun, Hongxia Hu, Sinian Liu, Man Jiang, Jing Cao, Jianming
Wang)
Zhu RR designed the study, conducted the survey and drafted the
manuscript; Shi J conducted the survey; Yang M performed the statistical
analysis and Guan HJ designed the study and
revised the manuscript
Foundations: Supported by the
National Natural Science Foundation of China (No.81070718); the 333 Project of
Jiangsu Province, China (No.BRA2010173).
Conflicts of Interest: Zhu RR, None; Shi J, None; Yang M, None; Guan HJ,
None.
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