Prevalence of and risk factors for age-related macular degeneration in Nepal: the Bhaktapur Retina Study

Figures & data

Table 1 Comparison of responders and nonresponders in the study population

Variable	Responders (n=1,860)	Nonresponders (n=240)	P-value
Age (years), mean ± SD	69.64±7.31	69.50±7.93	0.782
Male, n (%)	821 (44.14)	110 (45.83)	0.629
Female, n (%)	1,039 (55.86)	130 (54.17)

Table 2 Demographic characteristics of study subjects across various groups of AMD

Characteristics	All study subjects (n=1,860), n (%)	Group 1: no AMD (n=1,201), n, % (95% CI)	Group 2: mild dry AMD (n=484), n, % (95% CI)	Group 3: intermediate dry AMD (n=143), n, % (95% CI)	Group 4: geographic atrophy (n=19), n, % (95% CI)	Group 5: wet AMD (n=13), n, % (95% CI)
Age (years)
60–69	950 (51.08)	628, 66.11 (63–69)	231, 24.32 (22–27)	73, 7.68 (6–9)	11, 1.16 (0.57–0.06)	7, 0.74 (0.29–1.51)
70–79	697 (37.47)	442, 63.41 (60–67)	195, 27.98 (25–31)	52, 7.46 (6–10)	4, 0.57 (0.01–1)	4, 0.57 (0.01–1)
≥80	213 (11.45)	131, 61.50 (55.00–68.00)	58, 27.23 (21–34)	18, 8.45 (5–13)	4, 1.88 (0.05–5)	2, 0.94 (0.01–33)
Gender
Male	821 (44.14)	536, 65.29 (62.00–68.00)	210, 25.58 (23–29)	61, 7.43 (6–9)	8, 0.97 (0.04–2)	6, 0.73 (0.02–1)
Female	1,039 (55.86)	665, 64.00 (61–67)	274, 26.37 (24–29)	82, 7.89 (6–10)	11, 1.06 (0.52–1.88)	7, 0.67 (0.27–1.38)
Occupation
Agriculture	1,351 (72.63)	855, 63.29 (61–66)	368, 27.24 (25–30)	104, 7.70 (6.33–9.25)	13, 0.96 (0.05–1)	11, 0.81 (0.04–1)
Others	509 (27.37)	346, 67.98 (64–72)	116, 22.79 (19–27)	39, 7.66 (5–10)	6, 1.18 (0.04–2)	2, 0.39 (0.00–1)
Literacy
Illiterate	1,433 (77.04)	920, 64.20 (62–67)	376, 26.24 (24–28)	112, 7.82 (6–9)	14, 0.98 (0.53–1.63)	11, 0.77 (0.03–13)
Literate	427 (22.96)	281, 65.81 (61–70)	108, 25.29 (21–30)	31, 7.26 (4.98–10.14)	5, 1.17 (0.38–2.71)	2, 0.47 (0.05–1.68)

Abbreviations: AMD, age-related macular degeneration; CI, confidence interval.

Table 3 Prevalence and laterality of dry and wet AMD in study subjects

AMD types	Prevalence, n, % (95% CI)	Unilateral, n, % (95% CI)	Bilateral, n, % (95% CI)
All AMD	659, 35.43 (33.25–37.65)	243, 36.87 (33.18–40.68)	416, 63.13 (59.31–66.82)
Dry AMD	646, 34.73 (32.56–36.94)	242, 37.46 (33.72–41.32)	404, 62.54 (56.67–66.28)
Wet AMD	13, 0.70 (0.37–1.19)	1, 7.69 (0.19–36.03)	12, 92.31 (63.97–99.80)

Abbreviations: AMD, age-related macular degeneration; CI, confidence interval.

Table 4 Participant characteristics in early and late AMD among subjects with AMD

Characteristics	Early AMD (n=627)	Late AMD (n=32)	Total, n (%)	P-value
Smoking habit, n, % (95% CI)
Nonsmokers	277, 96.18 (93.26–98.07)	11, 3.82 (1.92–6.73)	288 (43.70)	0.526
Present smokers	172, 93.99 (8.94–9.69)	11, 6.01 (3.03–10.50)	183 (27.77)
Past smokers	178, 94.68 (90.43–97.42)	10, 5.32 (2.57–9.56)	188 (28.53)
Cigarettes per day (mean ± SD)	8.17±6.73	9.00±7.95	8.21±6.78	0.634
Alcohol consumption, n, % (95% CI)
No alcohol	260, 96.65 (93.74–98.45)	9, 3.35 (1.54–6.25)	269 (40.82)	0.147
Present alcohol	281, 93.36 (89.92–95.89)	20, 6.64 (4.10–10.07)	301 (45.68)
Past alcohol	86, 96.63 (90.46–99.29)	3, 3.37 (0.70–9.53)	89 (13.51)
Hypertension, n, % (95% CI)
Non-hypertensive cases	402, 95.26 (92.77–97.08)	20, 4.74 (2.91–7.22)	422 (64.03)	0.852
Hypertensive cases	225, 94.94 (91.32–97.35)	12, 5.06 (2.64–8.67)	237 (35.97)
Cases without diabetes, n, % (95% CI)	575, 95.20 (93.17–96.76)	29, 4.80 (3.23–6.82)	604 (91.65)	0.829
Cases with diabetes, n, % (95% CI)	52, 94.55 (84.87–98.86)	3, 5.45 (1.13–15.12)	55 (8.35)
BMI ≤24.9 kg/m^2, n, % (95% CI)	381, 94.54 (91.85–96.54)	22, 5.46 (3.45–8.14)	403 (61.15)	0.366
BMI ≥25 kg/m^2, n, % (95% CI)	246, 96.09 (92.93–98.11)	10, 3.91 (1.88–7.06)	256 (38.85)
Abdominal girth, cm (mean ± SD)	80.86±12.31	79.37±11.65	80.79±12.27	0.504
Myopia, n, % (95% CI)	63, 92.65 (83.66–97.56)	5, 7.35 (2.43–16.33)	68 (10.32)	0.062
Hypermetropia, n, % (95% CI)	86, 100 (83.66–97.56)	0, 0	86 (13.05)
Others, n, % (95% CI)	478, 94.65 (92.31–96.44)	27, 5.35 (3.55–7.68)	505 (76.63)
Phakic cases, n, % (95% CI)	520, 96.47 (94.55–97.86)	19, 3.53 (2.13–5.45)	539 (81.79)	0.001
Pseudophakic cases, n, % (95% CI)	107, 89.17 (82.18–94.10)	13, 10.83 (5.89–17.81)	120 (18.29)

Abbreviations: AMD, age-related macular degeneration; CI, confidence interval; BMI, body mass index.

Figure 1 Visual status based on BCVA among the study subjects.

Abbreviations: BCVA, best-corrected visual acuity; AMD, age-related macular degeneration.

Table 5 Risk factors for AMD using logistic regression analysis

Characteristics	No AMD (n=1,201)	AMD (n=659)	OR (95% CI)	P-value
Age (years), n (%)
60–69	628 (66.11)	322 (33.89)	1
70–79	442 (63.41)	255 (36.59)	1.12 (0.92–1.38)	0.258
≥80	131 (61.50)	82 (38.50)	1.22 (0.89–1.66)	0.203
Gender, n (%)
Male	536 (65.29)	285 (34.71)	1
Female	665 (64.00)	374 (36.00)	1.06 (0.87–1.28)	0.566
Occupation, n (%)
Agriculture	855 (63.29)	496 (36.71)	1	0.06
Other occupations	346 (67.98)	1,639 (32.02)	0.81 (0.65–1.01)
Literacy, n (%)
Illiterate	920 (64.20)	513 (35.80)	1
Literate	281 (65.81)	146 (34.19)	0.93 (0.74–1.17)	0.542
Hypertension, n (%)
No	795 (65.32)	422 (34.68)	1
Yes	406 (63.14)	237 (36.86)	1.10 (0.90–1.34)	0.349
Diabetes, n (%)
No	1,088 (64.30)	604 (35.70)	1
Yes	1,139 (67.26)	55 (32.74)	0.88 (0.62–1.23)	0.445
Smoking, n (%)
Nonsmoker	524 (64.53)	288 (35.47)	1
Smoker	677 (64.60)	371 (35.40)	0.99 (0.82–1.21)	0.976
Cigarettes per day, (mean ± SD)	7.19±5.63	8.21±6.78	1.03 (1.01–1.05)	0.025
Alcohol, n (%)
No alcohol	525 (66.12)	269 (33.88)	1
Alcohol	676 (63.41)	390 (36.59)	1.13 (0.93–1.36)	0.228
AMD awareness, n (%)
Yes	74 (71.84)	29 (28.16)	1
No	1,127 (64.14)	630 (35.86)	1.43 (0.92–2.21)	0.114
Myopia, n (%)	119 (63.64)	68 (36.36)	1
Hypermetropia, n (%)	163 (65.46)	86 (34.54)	0.92 (0.62–1.37)	0.693
Others, n (%)	619 (64.54)	505 (35.46)	0.96 (0.70–1.32)	0.809
Pseudophakia, n (%)
No	1,040 (65.86)	539 (34.14)	1
Yes	161 (57.30)	120 (42.70)	1.44 (1.11–1.86)	0.006

Abbreviations: AMD, age-related macular degeneration; OR, odds ratio; CI, confidence interval.