Understanding Presbyopia in Asmara: Prevalence, Association with Refractive Error, and Age-Based Addition

Figures & data

Figure 1 Near addition distribution across the age groups.

Notes: Vertical line = near addition. Horizontal line = age. Figure 1 illustrates the result of post hoc tests which were run on the addition across the age groups and the result showed there was a significant difference in the addition across the different age groups with a p-value of <0.001.

Figure 2 Comparison of the addition of different populations.

Notes: Vertical line = near addition values. Horizontal line = age groups. The variation in addition for these populations is illustrated in Figure 2.

Table 1 Demographic Distribution of Participants

Categories	Previous Refraction		P-value (x^2)	Total
	Yes	No
Gender
Female	228 (35.9%)	407 (64.1%)	0.818 (0.06)	635 (48.5)
Male	238 (35.3%)	437 (64.7%)		675 (51.5)
Age
35–40 years	61 (20.9%)	231 (79.1%)	< 0.001 (91.245)	292 (22.3%)
41–45 years	84 (26.9%)	228 (73.1%)		312 (23.8%)
46–50 years	128 (38.1%)	208 (61.9%)		336 (25.6%)
51–55 years	88 (45.4%)	106 (54.6%)		194 (14.8%)
56–60 years	105 (59.7%)	71 (40.3%)		176 (13.4%)
Occupation
Office worker	203 (40.3%)	301 (59.7%)	0.019 (7.946)	504 (38.5%)
Housewife	112 (32.3%)	235 (67.7%)		347 (26.5%)
Labour worker	151 (32.9%)	308 (67.1%)		459 (35.0%)
Address
South east	99 (36.7%)	171 (63.3%)	0.073 (6.981)	270 (20.6%)
North east	115 (35.1%)	213 (64.9%)		328 (25%)
South west	109 (30.7%)	246 (69.3%)		355 (27.1%)
North west	143 (40.1%)	214 (59.9%)		357 (27.3%)
Refractive error
Hyperopic	189 (44.4%)	235 (55.6%)	<0.001 (52.038)	423 (32.3%)
Emmetropic	177 (26.7%)	488 (73.3%)		663 (50.6%)
Myopic	68 (42.2%)	95 (57.8%)		161 (12.3%)
Mixed Astigmatism	32 (56.1%)	25 (43.9%)		57 (4.4%)

Table 2 Prevalence of Presbyopia in Different Variables

Variables	Categories	Non-Presbyopic	Presbyopic	P value Chi-square
Overall		339 (25.9)	971 (74.1)
Age
	35–40 years	260 (89.3%)	31 (10.7%)	< 0.001 (832.3)*
	41–45 years	702 (2.4%)	242 (77.6%)
	46–50 years	6 (1.8%)	330 (98.2%)
	51–55 years	0 (0%)	194 (100%)
	56–60 years	3 (1.7%)	174 (98.3%)
Mean age±SD		38.87±3.4	49.49±5.77	<0.001
Gender
Gender	Females	189 (29.8%)	448 (70.2%)	0.002 (9.70)
	Males	149 (22.2%)	524 (77.8%)
Occupation	Office worker	135 (27%)	369 (73%)	0.002 (12.18)
	Housewives/unemployed	109 (31.3%)	239 (68.7%)
	Labor	94 (20.5%)	364 (79.5%)
Sub zone	South east	40 (14.8%)	230 (85.2%)	0.157 (5.86)
	North east	39 (11.9%)	289 (88.1%)
	South west	51 (14.4%)	304 (85.6%)
	North west	52 (14.6%)	305 (85.4%)
Previous prescription	With prev. Px	30 (6.4%)	436 (93.6%)	< 0.001 (69.11)
	No prev. Px	152 (18%)	692 (72%)

Note: *High association of age and addition.

Table 3 Multivariate Analysis of the Factors Affecting Presbyopia Age Adjusted and Non- Adjusted

Age Included Analysis						Age Excluded Analysis
Variables	Crude OR (95% CI)	P value	Adjusted OR (95% CI)	P value		Crude OR (95% CI)	P value	Adjusted OR (95% CI)	P value
Age	1.76 (1.64–1.88)	<0.001	1.76 (1.64–1.88)	<0.001
Gender
Females	1(Ref)	0.031	1(Ref)	0.051		1 (Ref)	0.059	1 (Ref)	0.051
Males	0.59 (0.36–0.95)		0.67 (0.45–1.00)			1.34 (0.99–1.83)		1.35 (0.99–1.84)
Occupation
Office worker	1(Ref)	0.156	1(Ref)			1(Ref)	0.037	1 (Ref)	0.037
Housewives/ unemployed	0.98 (0.55–1.73)	0.94	0.97 (0.55–1.67)			1.02 (0.72–1.45)	0.92	1.01 (0.71–1.44)	0.95
Laborer	1.53 (0.96–2.45)	0.077	1.76 (1.64–1.88)			1.47 (1.08–2.00)	0.014	1.47 (1.08–1.99)	0.015
Sub Zone
South East	1 (Ref)	0.57				1 (Ref)	0.219
North East	1.42 (0.77–2.6)	0.26				1.09 (0.74–1.61)	0.665
South West	0.99 (0.55–1.79)	0.97				0.76 (0.53–1.10)	0.150
North West	1.07 (0.6–1.93)	0.82				0.90 (0.62–1.32)	0.599
Chief Complaint
Vision comp.	1 (Ref)	0.96				1 (Ref)	0.666
Ocular disease	1.06 (0.64–1.75)	0.82				1.15 (0.84–1.57)	0.396
Discomfort	0.95 (0.40–2.22)	0.89				1.12 (0.65–1.92)	0.679
Previous prescription
With previous	1 (Ref)	0.92				1 (Ref)	<0.001	1 (Ref)	<0.001
No previous prescription	1.02 (0.64–1.63)					0.40 (0.30–0.54)		0.39 (0.29–0.53)

Table 4 Addition Table for the Different Genders Across the Age Groups

Gender	Age Groups	N	Addition	Standard Deviation	Lower Bound	Upper Bound	ANOVA P value (F)
Females	35–40 years	181	0.75 DS	0.48	0.68	0.82	<0.001 (425.7)
	41–45 years	149	1.35 DS	0.27	1.31	1.40
	46–50 years	152	1.81 DS	0.28	1.76	1.85
	51–55 years	81	2.18 DS	0.28	2.12	2.24
	56–60 years	72	2.35 DS	0.31	2.28	2.43
Males	35–40 years	111	0.60 DS	0.41	0.52	0.68	<0.001 (05.63)
	41–45 years	163	1.25 DS	0.36	1.20	1.31
	46–50 years	184	1.75 DS	0.29	1.69	1.78
	51–55 years	113	2.13 DS	0.24	2.08	2.18
	56–60 years	104	2.38 DS	0.31	2.32	2.44
All	35–40 Years	292	0.70 DS	0.46	0.64	0.75	<0.001 (914.97)
	41–45 Years	312	1.30 DS	0.32	1.27	1.34
	46–50 Years	336	1.77 DS	0.29	1.74	1.80
	51–55 Years	194	2.15 DS	0.26	2.11	2.19
	56–60 Years	176	2.37 DS	0.31	2.32	2.41

Table 5 Near Addition to Different Refractive Status

Age Category	Refractive Error	N	Near Addition	Anova p value (F)
35–40 years	Emmetropic	201	0.61	<0.001 (11.51)
	Hyperopic	57	0.99
	Myopic	28	0.66
	Mixed astigmatism	5	1.00
41–45 years	Emmetropic	174	1.27	<0.007 (4.08)
	Hyperopic	93	1.40
	Myopic	29	1.22
	Mixed astigmatism	16	1.22
46–50 years	Emmetropic	156	1.77	<0.029 (3.04)
	Hyperopic	114	1.80
	Myopic	49	1.67
	Mixed astigmatism	14	1.86
51–55 years	Emmetropic	89	2.16	<0.019 (3.41)
	Hyperopic	68	2.18
	Myopic	24	2.01
	Mixed astigmatism	12	2.25
56–60 years	Emmetropic	43	2.31	<0.446 (0.89)
	Hyperopic	91	2.38
	Myopic	31	2.37
	Mixed astigmatism	10	2.48

Table 6 Predictive Factors for Addition

Categories	Variables	Coefficient	Significance	Importance
Addition	Age	0.061	0.00	0.774
	AA	−0.138	0.00	0.199
	Gender	0.085	0.00	0.014
	Refractive error	−0.061	0.001	0.009
	Occupation	0.049	0.005	0.004