Incidence of Blindness and Severe Visual Impairment in Germany: Projections for 2030

Abstract

Purpose.: Estimates of the incidences of severe visual impairment and blindness (SVI/B) and their causes are key to good health service planning. Thus, the database of Germany's largest state's blind registry was used to estimate current incidence rates (IR) and to project rates for Germany in 2010 and 2030.

Methods.: The sample consisted of 3328 blind/severely visually impaired individuals newly registered between 2000 and 2008. According to German law, SVI and B were defined as visual acuity equal to or below 20/1000 and 20/400, respectively, in the better seeing eye. Data of the reference population were stratified by age and sex and were used to estimate current IRs. Standardized IRs were estimated for Germany for 2010 and 2030 using national demographic projections.

Results.: Age-related macular degeneration (AMD) accounted for 50% of all incidence of SVI/B (5.56/100,000 personyears (PY), followed by glaucoma (15%; 1.65/100,000 PY) and diabetic eye disease (10%; 1.16/100,000 PY). All current IRs will rise by 2030, with the most pronounced increase in AMD. By 2030, a national AMD IR of 9.5/100,000 PY is expected, accounting for 57% of all incidence of SVI/B in Germany. The incidence of SVI/B in women will be more than twofold compared to men in 2030 (9187 vs. 3716 incident cases in 2030).

Conclusions.: There will be a dramatic increase of SVI/B by 2030 in Germany, leading to a substantial increase in the need for health and social service provision, with a focus on visually impaired elderly women.

In all industrialized countries, blindness and visual impairment are assumed to be on the rise, as it is largely a problem of old age and populations in industrialized countries, including Germany, are ageing rapidly. ¹ In Germany, no data on visual impairment and blindness generated by large epidemiologic studies are available. All published incidence or prevalence rates for various causes of visual impairment in Germany to date are based on the analysis of data collected by social welfare institutions responsible for the distribution of allowances granted on the basis of the presence of visual impairment or data collected by insurance companies. ^2,3 Visual impairment is assumed to amount to 80,000 to 500,000 blind and 215,000 to 1,000,000 visually impaired persons in Germany. ² The large variation in the estimated numbers results from differing definitions of blindness and visual impairment, as well as varying data sources and reference populations. 

Previously reported incidence rates are based on a collection of data from social welfare agencies in the districts of Württemberg-Hohenzollern, ^3,4 which is part of the federal state of Baden-Württemberg, and Hessia, ⁵ and were published more than 5 and 10 years ago. The state of Northrhine-Westfalia (NRW) which borders the Netherlands, Belgium, and France and is located in the center of Germany, is the most populous federal state. The agencies responsible for the distribution of the allowance for the blind are the largest welfare institutions of their kind. Thus, we analyzed the data collected by the Landschaftsverband Rheinland (LVR), the social welfare institution responsible for the allocation and distribution of allowances to the blind and visually impaired in Northrhine, one of the two administrative districts of the state of NRW. To be able not only to project the future development of blindness and visual impairment in Germany but also to enable health services to be planned accordingly, incidence rates and projections of their future changes are key. Thus, we calculated current incidence rates and projected them to 2030. 

Methods

The two welfare institutions responsible for the collection of data regarding disability due to blindness or visual impairment are the Blindengeldstellen, which assess eligibility for blind allowances and subsequently distributes the allowance, and the Versorgungsämter, which issues other allowances (exemption from fees for public transport and tax relief) based on any disability that is in accordance with legally specified requirements. Only the Blindengeldstellen record is based on a basic ophthalmic examination that is required for every application. However, data are not recorded centrally at a national level, but only on a state or substate level, and the data are not used for anything else but the assessment of the individual application. 

The Sample

The definition of blindness and visual impairment as laid down by German law is strict in comparison to the definitions of the World Health Organization (WHO) or other countries. Blind is defined according to German regulations as a best corrected visual acuity of 20/1000 or less in the better eye or a visual field restriction to no more than the central 5°. Severe visual impairment is defined as a visual acuity of not more than 20/400 in the better eye or a restriction of the visual field to the central 10°. ² Persons in these two categories qualify for the allowance after review of an application including medical and ophthalmic reports by the LVR. As these definitions are well below the cutoff of common definitions of blindness (20/400 for example is the cutoff used by the WHO to define blindness), we felt it justified combining blindness and severe visual impairment in all our analyses and will always refer to blindness and severe visual impairment in the following. For an individual to be granted the blind allowance, the condition has to be assessed by an ophthalmologist as permanent or unlikely to ever improve to levels of meaningful functional vision. Data extracted from files included date of registration and sociodemographic, medical, and ophthalmic findings. 

Based on German law, most of the blind and severely visually impaired are entitled to a substantial allowance (∼400 €/mo for blind and ∼100 €/mo for severely visually impaired persons). As the allowance is independent of other sources of income, it can be assumed that most eligible persons apply for it and thus are registered with the respective welfare institution. ⁶ The results presented in this study are based on a large representative sample of the archives at the blind registry of the LVR in Northrhine, Germany, including the newly blind registered between 2000 and 2008. 

All blind and severely visually impaired persons living in the defined geographic area of Northrhine would have to apply to the LVR to be assessed for their eligibility to receive blind allowance. Thus, records for the reference area can be assumed to be close to complete, as the blind allowance provides a unique incentive for registration, unlike findings from the United Kingdom, for example, where registration does not imply a direct financial incentive. ^7,8 The study had to rely on the data collected by the LVR and maintained in their archives, with no option to verify stated diagnoses or complete missing information. However, as reports submitted with each application have to be based on an ophthalmic examination, the level of accuracy can be assumed to be high. It is unknown how many persons who qualify for the blind allowance did not apply. As the allowance is substantial in comparison to other welfare allowances, rates have been reported to be very high. ^3,4  

All applications are based on the same form, which is submitted to and archived at the LVR. One part of the form captures sociodemographic data, another part pertains to the financial status of the applicant, and a third part has to be completed by an ophthalmologist. This part contains information about visual acuity (monocular and binocular, best corrected), visual fields (optional), ocular history, ocular findings, main cause of vision loss, concurrent ocular disease, relation of main cause of blindness to trauma (yes/no) or war time injuries (yes/no), permanency of vision loss (yes/no). Data extracted from files included date of registration and sociodemographic, medical, and ophthalmic findings. In cases in which more than one main cause of vision loss was stated, the main cause was determined after review by two ophthalmologists. In cases in which no agreement could be achieved, the main cause of blindness was recorded as “missing” (summarized as missing, under Causes of Blindness and Severe VI in Table 1; n = 147, 4.4%). Glaucoma includes all types of glaucoma, irrespective of age of onset or etiology. Diabetic eye disease includes diabetic retinopathy as well as diabetic maculopathy for both type I and type II diabetics. Retinal dystrophies include macular and generalized retinal dystrophies. Others include several different diagnoses, which could not be summarized into other diagnostic categories (e.g., cerebral disease, malformations, uveitis, retinopathy of prematurity [ROP] and trauma). All parts are mandatory except the last part completed by the ophthalmologist, which does not need to be submitted if the applicant has already been registered as blind by another welfare agency (summarized as missing, under Causes of Blindness and Severe VI in Table 1; n = 188, 5.7%). 

Table 1.

 

Demographic Characteristics of the Sample

	Total Sample (n = 3328)	Men (n = 1011)	Women (n = 2100)
Age (SD), y, n = 219 missing	75.0 (19.97)	68.3 (21.8)	78.3 (18.0)
Age groups, n = 219 missing
<40	292 (8.8)	155 (15.3)	137 (6.5)
40–59	332 (10.0)	162 (16.0)	170 (8.1)
60–79	1210 (36.4)	425 (42.4)	784 (37.3)
≥80	1275 (38.3)	266 (26.3)	1009 (48.1)
Sex, n = 216 missing		1011 (32.5)	2100 (67.5)
Categories of VI, n = 0 missing
Blindness	2218 (66.6)	665 (65.8)	1342 (63.9)
Severe VI	1110 (33.4)	346 (34.2)	758 (36.1)
Cause of blindness or severe VI, n = 447 missing
AMD	1436 (49.8)	332 (32.8)	1089 (51.9)
Glaucoma	433 (15.0)	163 (16.1)	260 (12.4)
DED	305 (10.6)	109 (10.1)	187 (8.9)
RD	133 (4.6)	70 (6.9)	61 (2.9)
High myopia	114 (4.0)	29 (2.9)	84 (4.0)
Cataract	57 (2.0)	13 (1.3)	44 (2.1)
Others	403 (12.1)	107 (10.1)	156 (7.4)
Position in household, n = 383 missing
Head	1935 (65.7)	738 (73.0)	1196 (57.0)
Spouse	581 (19.7)	91 (9.0)	490 (23.3)
Child	147 (5.0)	78 (7.7)	69 (3.3)
Other	282 (9.6)	64 (6.3)	218 (10.4)
Institutionalized, n = 252 missing	282 (9.2)	76 (7.5)	206 (9.8)

 Data are reported as n (% of the total group), if not otherwise stated. Discrepancies arise in numbers between the total sample and the subgroups by gender as 217 cases were missing data on the sex of the person. VI, visual impairment; AMD, age-related macular degeneration; DED, diabetic eye diseases; RD, retinal dystrophies.

The database maintained at the LVR contained 15,725 blind and 4,640 severely visually impaired individuals as of December 2006 who received the allocated blind allowance at that time. All persons who move out of the area that is administered by the LVR or persons who die are removed from the register at the end of each calendar year, as it is linked to all regional registries. Information about these cases is retained by the LVR in their archive records. The population catchment of the LVR was 9,599,350 as of December 2006, which is the reference population for this study. All cases are identified by main and minor case numbers. Main case numbers are used for filing cases in main groups and are assigned from 1 to 100. Minor case numbers are assigned based on date of birth, sex, and initials. Every new case is assigned a main file number out of the 100 possible main file groups in ascending order with every 101st case restarting with 1. Thus 25 main case numbers were sampled by manual randomization (drawing 25 out of 100 numbers), and data were extracted from all files in the respective main case block, allowing for a randomized selection of a representative sample of available files (Supplementary Fig. S1). A representative sample of 5100 cases out of all persons currently receiving the blind allowance and registered with the LVR was recorded, consisting of one fourth of main case file numbers of the LVR archive. Of these, 3328 were newly registered between 2000 and 2008. 

Statistical Analysis

Visual acuity was converted into logMAR for statistical purposes. Semiquantitative values such as hand movement and counting fingers were converted to logMAR 2 for counting fingers (CF), 2.3 for hand movement (HM), 2.7 for light projection (LP), and 3 for no light projection (NLP) as suggested by Schulze-Bonsel et al. ⁹ and Bach et al. ¹⁰ A total of 3328 data sets were included into the final analysis. Several data sets were excluded, as they pertained to the same individual in cases of successive applications or in cases of an insufficient degree of completeness of the data provided in the application. 

Calculation of Incidence Rates

Data from the reference population of the defined geographic area administered by the LVR were stratified by age and sex and were used to calculate current incidence rates for Northrhine. Data available from the federal agency for statistics (Statistisches Bundesamt) on current characteristics of the German population (age and sex structure) as well as projections for 2010 and 2030 were used as reference population for the standardization of incidence rates obtained. Incidence rates for 2010 were calculated for validation of the estimated incidence rates, as data for 2010 will soon be available and thus make our calculation more robust. 

Incidence rates were calculated per 100,000 personyears (PY) of observation. The rates were calculated for all causes of blindness together and separately, per specified cause. Only main causes of blindness (one cause per person) were used, to increase precision. To obtain an overall incidence and allow for comparisons, the incidence rates were standardized to the 2008 German population (direct standardization). Projections of the German population for 2010 and 2030 were used to extrapolate incidence rates up to 2030 (direct standardization). Exact 95% confidence intervals (CI) of incidence rates in the age-specific strata were computed assuming a Poisson distribution of the incidence rates. Confidence intervals of standardized incidence rates were calculated using the moment-matching method. ¹¹ In addition, the absolute number of incident cases (c _i) were age-stratified, using the calculated incident rates (IRs) for the population of Northrhine as well as the whole of Germany as follows: c _i = IR · n _i · 100,000⁻¹, where n _i is the population of Northrhine or Germany in 2008, 2010, or 2030 (all analyses by SAS Statistical Software, ver. 9.2; SAS Inc, Cary, NC). 

Results

The sample's demographic characteristics are depicted in Table 1. The mean age was 75 years, with a large proportion of newly registered being female (67.5%). The total amount of incident cases of blindness and visual impairment was 11.10 per 100,000 PY. The largest amount of new registrations for blind allowance in the state of Northrhine between 2000 and 2008 was due to age-related macular degeneration (AMD; 5.56/100,000 PY), followed by glaucoma (1.65/100,000 PY) and diabetic eye disease (DED; 1.16/100,000 PY; Table 2; Fig. 1). Retinal and macular dystrophies (RD) and high myopia were the causes in similar proportions of incident cases (0.51 and 0.44/100,000 PY). Causes of blindness and severe visual impairment classified as “others” led to 1.56 incident cases per 100,000 PY. The most frequent diagnoses summarized as others were, in descending order, cerebral disease, malformations and colobomas, retinopathia prematurorum (ROP), and uveitis. Stratified by age, the highest number of incident cases was observed to be due to AMD in those aged 80 and over (81.26/100,000 PY), followed glaucoma in the same age group (14.44/100,000 PY), AMD in those aged 60 to 79 years (9.57/100,000 PY), and diabetic eye disease in those aged 80 and over (4.10/100,000 PY; Table 2). Stratified by sex, a larger number of incident cases were female, for all causes except for RDs. The difference was most marked for AMD and DED in those aged 60 to 79 years and ≥80 years (Table 2). 

Table 2.

 

All Incident Cases of Blindness and Severe Visual Impairment for Northrhine from 2000 to 2008, per 100,000 PY, by Cause of Blindness, Age Group, and Sex. Incidence Rate (95% confidence interval)

Causes	<40	40–59	60–79	≥80	All Ages
AMD
Total	0.04 (0.01 to 0.10)	0.55 (0.39 to 0.75)	9.57 (8.75 to 10.44)	81.26 (75.95 to 86.84)	5.56 (5.27 to 5.85)
F	0.07 (0.02 to 0.17)	0.44 (0.25 to 0.72)	12.64 (11.36 to 14.02)	92.25 (85.59 to 99.28)	8.29 (7.80 to 8.80)
M	0.02 (0.00 to 0.09)	0.66 (0.42 to 0.98)	5.94 (5.01 to 6.99)	53.25 (45.34 to 62.14)	2.66 (2.38 to 2.96)
Glaucoma
Total	0.42 (0.31 to 0.55)	0.84 (0.64 to 1.08)	2.97 (2.52 to 3.47)	14.44 (12.26 to 16.91)	1.65 (1.50 to 1.82)
F	0.36 (0.22 to 0.54)	1.10 (0.79 to 1.50)	3.11 (2.49 to 3.83)	14.40 (11.85 to 17.34)	1.98 (1.75 to 2.23)
M	0.48 (0.32 to 0.69)	0.58 (0.36 to 0.88)	2.80 (2.18 to 3.55)	14.55 (10.57 to 19.54)	1.30 (1.11 to 1.52)
DED
Total	0.13 (0.07 to 0.21)	0.62 (0.45 to 0.83)	3.65 (3.15 to 4.21)	4.10 (2.98 to 5.50)	1.16 (1.03 to 1.30)
F	0.12 (0.05 to 0.24)	0.63 (0.40 to 0.95)	4.27 (3.55 to 5.11)	4.67 (3.27 to 6.47)	1.42 (1.23 to 1.64)
M	0.13 (0.06 to 0.26)	0.61 (0.38 to 0.92)	2.93 (2.29 to 3.69)	2.65 (1.14 to 5.21)	0.87 (0.72 to 1.06)
RD
Total	0.48 (0.36 to 0.62)	0.50 (0.35 to 0.69)	0.65 (0.45 to 0.90)	0.37 (0.10 to 0.95)	0.51 (0.43 to 0.61)
F	0.41 (0.26 to 0.61)	0.44 (0.25 to 0.72)	0.60 (0.35 to 0.96)	0.52 (0.14 to 1.33)	0.46 (0.36 to 0.60)
M	0.54 (0.38 to 0.77)	0.55 (0.34 to 0.85)	0.70 (0.41 to 1.12)	-	0.56 (0.44 to 0.71)
High myopia
Total	0.11 (0.06 to 0.19)	0.41 (0.28 to 0.59)	1.07 (0.80 to 1.38)	1.31 (0.72 to 2.19)	0.44 (0.36 to 0.53)
F	0.12 (0.05 to 0.25)	0.58 (0.36 to 0.88)	1.59 (1.16 to 2.13)	1.43 (0.71 to 2.55)	0.64 (0.51 to 0.79)
M	0.10 (0.04 to 0.22)	0.25 (0.11 to 0.47)	0.45 (0.23 to 0.81)	0.99 (0.21 to 2.90)	0.23 (0.16 to 0.34)
Cataract
Total	0.07 (0.03 to 0.13)	0.07 (0.02 to 0.16)	0.49 (0.32 to 0.72)	1.68 (0.99 to 2.65)	0.22 (0.17 to 0.29)
F	0.10 (0.04 to 0.22)	0.06 (0.01 to 0.20)	0.67 (0.40 to 1.05)	2.21 (1.29 to 3.53)	0.34 (0.24 to 0.45)
M	0.03 (0.00 to 0.12)	0.08 (0.02 to 0.24)	0.29 (0.12 to 0.59)	0.33 (0.01 to 1.84)	0.11 (0.06 to 0.18)
Others
Total	1.02 (0.85 to 1.22)	1.11 (0.89 to 1.39)	2.42 (2.01 to 2.87)	6.34 (4.92 to 8.03)	1.56 (1.41 to 1.72)
F	0.93 (0.70 to 1.21)	1.13 (0.81 to 1.53)	2.58 (2.02 to 3.24)	6.88 (5.15 to 8.99)	1.69 (1.48 to 1.93)
M	1.11 (0.86 to 1.40)	1.10 (0.79 to 1.50)	2.23 (1.67 to 2.90)	4.96 (2.78 to 8.18)	1.42 (1.22 to 1.64)
All causes
Total	2.26 (2.00 to 2.54)	4.10 (3.65 to 4.59)	20.80 (19.59 to 22.08)	109.49 (103.32 to 115.94)	11.10 (10.69 to 11.51)
F	2.10 (1.75 to 2.51)	4.37 (3.72 to 5.11)	25.46 (23.63 to 29.69)	133.35 (114.66 to 130.41)	14.82 (14.17 to 15.49)
M	2.41 (2.03 to 2.83)	3.82 (3.22 to 4.52)	15.33 (13.81 to 16.92)	76.73 (67.17 to 87.26)	7.16 (6.69 to 7.64)

Figure 1.

 

Incidence of blindness and severe visual impairment 2000 to 2008 for Northrhine by cause per 100,000 PY.

Projecting incidence rates for the whole of Germany from 2010 to 2030, incidence rates for all causes except macular and retinal dystrophies (RD) increased over these 20 years, with AMD leading to an overall IR of blindness and severe visual impairment of 9.51 in 100,000 PY in 2030, followed by glaucoma with an IR of 2.4 in 100,000 PY and DED with an IR of 1.58 in 100,000 PY (Table 3; Fig. 2). Stratifying these projections by age groups and calculating incident cases based on the projected German population for 2010 and 2030, a total of 10,108 newly incident cases of blindness and severe visual impairment are expected for 2010 (Table 4). The number rises by approximately a quarter, to 12,941 newly incident cases in 2030 (Table 3; Fig. 3). Because of the ageing population, incident cases in the age groups below 40 and 40 to 59 years declined slightly, with a marked increase in incident cases between 2010 and 2030 being found in the age groups 60 to 79 years and 80 years and older (Table 3). Cases due to AMD were calculated to rise from 5,285 to 7,340, constituting the largest proportion of newly incident cases. The increase is particularly large in the age group ≥80 years (3,484–5,109), constituting 61% of the total increase of incident cases from 2010 to 2030. 

Table 3.

 

Calculated Incident Cases for the Whole of Germany by Cause of Blindness, Sex, and Age Group for 2030

Causes	<40 (n = 29,047)	40–59 (n = 19,804)	60–79 (n = 22,065)	≥80 (n = 6,287)	All Ages (n = 77,203)
AMD
Total	12.14 (3.94 to 28.34)	108.95 (77.84 to 148.36)	2,110.61 (1,930.17 to 2,303.38)	5,108.68 (4,775.19 to 5,459.33)	7,340.39 (6,898.53 to 7,669.42)
F	9.64 (2.63 to 24.69)	43.07 (24.62 to 69.94)	1,492.02 (1,341.45 to 1,654.87)	4,113.31 (3,816.48 to 4,427.09)	5,658.04 (5,271.50–5,947.86)
M	2.45 (0.06 to 13.63)	66.14 (42.38 to 98.42)	609.00 (513.60 to 716.99)	973.33 (828.79 to 1,135.83)	1,650.92 (1,448.90–1,809.42)
Glaucoma
Total	121.42 (90.12 to 160.08)	166.15 (127.09 to 213.43)	654.58 (555.89 to 765.74)	908.08 (770.75 to 1,062.82)	1,850.24 (1,645.00 to 2,009.39)
F	50.62 (31.34 to 77.38)	107.67 (76.92 to 146.61)	366.75 (294.15 to 451.85)	642.16 (528.27 to 773.33)	1,167.20 (1,004.96 to 1,296.14)
M	70.93 (47.50 to 101.86)	57.88 (35.83 to 88.47)	287.58 (223.32 to 364.58)	266.00 (193.28 to 357.10)	682.39 (563.12 to 780.09)
DED
Total	36.43 (20.39 to 60.08)	122.57 (89.41 to 164.01)	805.64 (695.71 to 928.01)	257.78 (187.30 to 346.05)	1,222.42 (1,064.55 to 1,346.98)
F	16.87 (6.78 to 34.77)	61.91 (39.24 to 92.89)	504.29 (418.44 to 602.56)	208.27 (145.87 to 288.33)	791.34 (664.84 to 893.93)
M	19.57 (8.45 to 38.55)	60.63 (38.00 to 91.80)	300.27 (234.51 to 378.75)	48.36 (20.88 to 95.30)	428.83 (340.86 to 503.21)
RD
Total	138.42 (104.84 to 179.34)	98.06 (68.68 to 135.75)	142.67 (98.80 to 199.36)	23.43 (6.39 to 60.00)	402.58 (325.57 to 466.68)
F	57.85 (37.07 to 86.08)	43.07 (24.62 to 69.94)	70.85 (41.27 to 113.44)	23.14 (6.31 to 59.25)	194.91 (142.02 to 242.34)
M	80.71 (55.56 to 113.35)	55.12 (33.67 to 85.13)	71.90 (41.88 to 115.11)	-	218.54 (163.72 to 266.95)
High myopia
Total	31.57 (16.81 to 53.98)	81.71 (55.13 to 116.65)	234.98 (177.50 to 305.14)	82.02 (44.84 to 137.62)	430.28 (342.44 to 504.31)
F	16.87 (6.78 to 34.77)	56.52 (34.99 to 86.40)	187.54 (136.80 to 250.95)	63.64 (31.77 to 113.87)	324.58 (249.11 to 389.95)
M	14.67 (5.39 to 31.94)	24.80 (11.34 to 47.09)	46.52 (23.22 to 83.24)	18.14 (3.74 to 53.00)	104.14 (65.43 to 142.69)
Cataract
Total	19.43 (8.39 to 38.28)	13.62 (4.42 to 31.78)	109.10 (71.27 to 159.85)	105.45 (62.50 to 166.66)	247.60 (179.05 to 309.57)
F	14.46 (5.31 to 31.48)	5.38 (0.65 to 19.45)	79.19 (47.67 to 123.66)	98.35 (57.29 to 157.47)	197.38 (136.51 to 254.28)
M	4.89 (0.59 to 17.67)	8.27 (1.71 to 24.16)	29.60 (11.90 to 61.00)	6.05 (0.15 to 33.68)	48.81 (24.34 to 77.59)
Others
Total	296.26 (246.03 to 353.74)	220.63 (175.21 to 274.22)	532.90 (444.25 to 634.05)	398.38 (309.36 to 505.05)	1,448.18 (1,280.64 to 1,578.44)
F	132.58 (99.88 to 172.57)	110.36 (79.19 to 149.71)	304.24 (238.47 to 382.53)	306.62 (229.68 to 401.06)	853.79 (723.95 to 957.95)
M	163.87 (126.99 to 208.10)	110.24 (78.76 to 150.12)	228.38 (171.56 to 297.98)	90.68 (50.75 to 149.57)	593.17 (492.87 to 674.84)
All Causes
Total	655.67 (579.78 to 738.72)	811.70 (722.15 to 909.29)	4,590.47 (4,322.45 to 4,870.76)	6,883.83 (6,495.81 to 7,288.98)	12,941.70 (12,374.81 to 13,357.82)
F	298.91 (248.62 to 356.39)	427.97 (364.04 to 499.91)	3,004.88 (2,789.52 to 3,232.46)	5,455.49 (5,112.80 to 5,815.10)	9,187.25 (8,706.45 to 9,542.73)
M	357.08 (301.51 to 419.93)	383.09 (322.05 to 452.32)	1,573.26 (1,417.43 to 1,741.54)	1,402.56 (1,227.87 to 1,595.13)	3,715.99 (3,426.15 to 3,934.60)

 Data reported as incident cases (95% confidence interval); projected population figures n × 1,000.

Figure 2.

 

Estimated incident cases of blindness and severe visual impairment in Germany in 2010 and 2030 by cause and sex. The scale for the AMD graph differs from that of other graphs (y-axis ×4) for better visualization.

Table 4.

 

Calculated Incident Cases for the Whole of Germany by Cause of Blindness, Sex, and Age Group for 2010

Causes	<40 (n = 34,869)	40–59 (n = 25,517)	60–79 (n = 17,214)	≥80 (n = 4,287)	All Ages (n = 81,874)
AMD
Total	14.58 (4.73 to 34.01)	140.38 (100.29 to 191.16)	1,646.59 (1,505.82 to 1,796.98)	3,483.53 (3,256.12 to 3,722.62)	5,285.08 (4,970.36 to 5,519.43)
F	11.57 (3.15 to 29.64)	55.49 (31.72 to 90.11)	1,164.01 (1,046.55 to 1,291.06)	2,805.24 (2,602.81 to 3,019.24)	4,036.22 (3,762.89 to 4,241.17)
M	2.94 (0.07 to 16.36)	85.23 (54.61 to 126.81)	475.11 (400.68 to 559.35)	663.44 (564.92 to 774.20)	1,226.74 (1,079.20 to 1,342.50)
Glaucoma
Total	145.76 (108.18 to 192.16)	214.09 (163.76 to 275.00)	510.67 (433.68 to 597.39)	619.20 (525.56 to 724.72)	1,489.72 (1,330.25 to 1,613.39)
F	60.77 (37.62 to 92.89)	138.73 (99.11 to 188.90)	286.13 (229.48 to 352.52)	437.95 (360.28 to 527.40)	923.55 (799.33 to 1,022.26)
M	85.14 (57.02 to 122.28)	74.57 (46.16 to 113.99)	224.36 (174.22 to 284.42)	181.31 (131.74 to 243.40)	565.40 (470.42 to 643.20)
DED
Total	43.73 (24.47 to 72.12)	157.93 (115.20 to 211.33)	628.52 (542.76 to 723.99)	175.77 (127.72 to 235.97)	1,005.95 (878.90 to 1,106.20)
F	20.26 (8.14 to 41.73)	79.77 (50.57 to 119.69)	393.42 (326.45 to 470.09)	142.04 (99.48 to 196.64)	635.47 (535.95 to 716.18)
M	23.49 (10.14 to 46.28)	78.12 (48.96 to 118.28)	234.25 (182.95 to 295.48)	32.97 (14.23 to 64.96)	368.84 (294.91 to 431.34)
RD
Total	166.16 (125.85 to 215.28)	126.35 (88.49 to 174.92)	111.30 (77.08 to 155.53)	15.98 (4.35 to 40.91)	419.79 (342.30 to 484.29)
F	69.45 (44.50 to 103.33)	55.49 (31.72 to 90.11)	55.27 (32.20 to 88.50)	15.78 (4.30 to 40.41)	195.99 (145.04 to 241.69)
M	96.89 (66.69 to 136.07)	71.02 (43.38 to 109.69)	56.09 (32.67 to 89.80)		231.21 (174.68 to 281.13)
High myopia
Total	37.90 (20.18 to 64.80)	105.29 (71.04 to 150.31)	183.32 (138.48 to 238.05)	55.93 (30.58 to 93.84)	382.43 (306.96 to 446.03)
F	20.26 (8.14 to 41.73)	72.83 (45.08 to 111.33)	146.31 (106.72 to 195.78)	43.40 (21.67 to 77.66)	282.79 (219.04 to 338.02)
M	17.62 (6.46 to 38.34)	31.96 (14.61 to 60.67)	36.29 (18.12 to 64.94)	12.36 (2.55 to 36.13)	98.23 (63.23 to 133.11)
Cataract
Total	23.32 (10.07 to 45.95)	17.55 (5.70 to 40.95)	85.11 (55.60 to 124.71)	71.91 (42.62 to 113.65)	197.89 (144.81 to 245.87)
F	17.36 (6.37 to 37.79)	6.94 (0.84 to 25.06)	61.78 (37.19 to 96.47)	67.07 (39.07 to 107.39)	153.15 (107.22 to 196.08)
M	5.87 (0.71 to 21.21)	10.65 (2.20 to 31.13)	23.10 (9.29 to 47.59)	4.12 (0.10 to 22.96)	43.74 (22.49 to 68.74)
Others
Total	355.65 (295.34 to 424.64)	284.28 (225.76 to 353.33)	415.74 (346.58 to 494.65)	271.65 (210.95 to 344.38)	1,327.31 (1,181.19 to 1,440.93)
F	159.15 (119.90 to 207.16)	142.19 (102.04 to 192.90)	237.35 (186.05 to 298.44)	209.11 (156.64 to 273.52)	747.79 (639.39 to 834.75)
M	196.71 (152.45 to 249.82)	142.04 (101.48 to 193.42)	178.16 (133.84 to 232.47)	61.81 (34.60 to 101.95)	578.74 (485.33 to 654.82)
All causes
Total	787.08 (695.99 to 886.78)	1,045.86 (930.47 to 1,171.60)	3,581.26 (3,372.16 to 3,799.92)	4,693.97 (4,429.38 to 4,970.24)	10,108.20 (9,678.40 to 10,423.70)
F	358.82 (298.45 to 427.82)	551.43 (469.05 to 644.12)	2,344.29 (2,176.27 to 2,521.83)	3,720.59 (3,486.89 to 3,965.85)	6,974.97 (6,618.58 to 7,238.47)
M	428.65 (361.94 to 504.10)	493.60 (414.96 to 582.81)	1,227.36 (1,105.79 to 1,358.64)	956.01 (836.94 to 1,087.27)	3,105.70 (2,872.97 to 3,281.24)

 Data reported as incident cases (95% confidence interval); projected population figures n × 1,000.

Figure 3.

 

Estimated incident cases of blindness and severe visual impairment for Germany for all causes 2010 and 2030. F, women; M, men.

In 2030, the female population will exceed the male population by approximately 4 million, of whom more than 2 million will be ≥80 years. Among this population, the incidence rates of AMD, glaucoma, and DED will be more than four times higher than in their male counterparts for AMD and DED and more than twice for glaucoma (Table 3). In total, the incidence of severe visual impairment and blindness in women will be more than twice as high than that in men in 2030 (9,187 vs. 3,716), which is an increase of approximately 32% in the incidence of blindness in women compared to 2010 (from 6,975 to 9,187) whereas the incidence in men is expected to increase much less over the next 20 years (3,106 to 3,716; +20%). 

Discussion

The main finding of our study is a further increase in blind and severely visually impaired persons in Germany until 2030, affecting many more elderly women than men. AMD will remain the main cause of blindness and severe visual impairment. This prediction calls for early adequate health care planning, including preventative measures with a focus on elderly women who often are widowed and live by themselves. ¹²  

In comparison to other studies based on data from Germany, incidence rates calculated for southern Germany based on data from 1990 to 1998 were much higher. ⁴ However, these data were reviewed based on the 1994 to 1998 data, and the calculated incidence rates declined and compare well with our data (12.27 per 100,000 PYs for the total sample; 5.29 AMD, 2.86 optic atrophy, 2.43 glaucoma and 2.13 diabetic eye disease). ³ The higher incidence of blindness in women, as well as the widening of this gap with age, is another finding in keeping with other studies, ¹³ along with the main causes of blindness and severe visual impairment. ⁵  

Compared with the IRs based on the national blind register of Israel (0.037% for all causes), ¹⁴ IRs calculated for Northrhine are lower, based on the stricter definition of blindness and severe visual impairment applied by the German government. Major causes of blindness were the same. Our data compare well with prevalence and/or incidence rates reported from major population-based cohort studies. ^{15 –18} However, direct comparisons are difficult, as mostly an older age group was followed up in these studies and the results were reported as cumulative incidence over 5- to 15-year time intervals. 

Blindness due to AMD and diabetic eye disease may decrease, as anti-VEGF therapy is now readily available, ^{19 –21} leading possibly to a shift from registered blindness to severe visual impairment in the coming years. This may lead to even a larger proportion of elderly persons with severe visual impairment and thus poor visual functioning living in the community, ²² who should be considered when planning services. 

Projections of blindness and severe visual impairment for Germany, ²³ as well as other western, mainly Caucasian, countries such as Australia, ²⁴ show a steep increase until 2030, with a widening gap between men and women that increases with age. Projections for Australia show a fourfold risk of severe visual impairment for women aged 50 and older compared with that for men, ²⁴ a finding well in keeping with our data. Projections for vision-threatening diabetic retinopathy for the United States for 2050 predict a threefold increase, mostly in persons aged 65 and older. ²⁵ Based on our data, IRs for blinding diabetic eye disease are expected to increase by 20% until 2030. The increase will be mostly in those aged over 60. 

A strength of this study is the long-term data on blindness and severe visual impairment available for a defined geographic region. Limitations of our data are based on the study's being a register analysis. However, the data are derived from a representative sample of Germany's largest blind register in Northrhine. The substantial blind allowance provided in Germany creates a unique incentive for registration, and all blind and severely visually impaired persons living in the defined geographic area of Northrhine have to apply to the LVR to be assessed for their eligibility for the blind allowance. Thus, records for the reference area can be assumed to be close to complete, unlike findings from for example the UK where registration does not imply a direct financial incentive. ^7,8 It is unknown how many persons who would qualify for the blind allowance did not apply. As the allowance is quite substantial in comparison to other welfare allowances, rates have been reported to be very high. ^3,4 Other studies have shown that data gathered from social welfare registers are of high quality and are representative of the respective populations. ^{26 –28} Our study had to rely on the data collected by the LVR and maintained in their archives, with no option to verify stated diagnoses or complete missing information. As reports submitted with each application include an ophthalmic examination and are assessed by a second ophthalmologist at the LVR, the level of accuracy can be expected to be high. Persons who die or migrate are removed from the register on an annual basis, and, with only basic information retained in the register database and individual files no longer kept in the archive, these cases are only part of the overall incidence calculations. However, the attrition due to death can be expected not to change significantly over time. Moreover, migration is likely to be very limited in severely visually impaired and blind persons, especially the elderly. Thus, we feel that these factors do not significantly confound our results. 

The definition of blindness according to which the LVR assesses eligibility for the blind allowance differs from commonly used international definitions of blindness (e.g., WHO's definition) in that it is much more strict (detailed in the Methods section). ¹ Thus, the number of blind and severely visually impaired persons can be expected to be considerably higher applying WHO's definition of blindness and visual impairment. 

The much higher number of blind compared with severely visually impaired persons in our sample is most likely due to a system bias (definition of “severe vision impairment” with a very limited span), and future studies are needed to clarify the real proportion of moderately and severely visually impaired persons. The observed discrepancy will not be found in population-based studies or clinical samples anywhere in Germany and is an additional reason, why blindness and severe visual impairment were analyzed together. 

The age and sex distribution of the population living in the LVR catchment area is similar to that in the rest of Germany (for statistics for all of Germany, see Ref. 29), with an almost equal proportion of males and females up to the age of 60, above which the proportion of women increases. ^12,29 In the LVR catchment area, 10.8% of people are non-German citizens (at the end of 2004 ³⁰ ), being similar to the average for Germany (8.8% ³¹ ). The ethnicity of the population in this region is very similar to that in the rest of Germany, where most citizens are Caucasian. However, a systematic census of ethnicity in Germany is not available. The extrapolation to 2030 for the whole country as well as the number calculated for Northrhine should be interpreted with caution. Also, only demographic data and projections were factored in, whereas potential new therapies and preventative measures that may become available within the next two decades cannot be taken into account. However, as incidence data are very difficult to gather, we felt justified in using the data available through Germany's largest blind register to investigate time trends regarding blindness and severe visual impairment in Germany. 

In conclusion, the projected dramatic increase in blindness and severe visual impairment until 2030 will lead to a substantial increase in the need for medical service provision, social service provision, and financial resources available. Health care planners should take the preponderance of visually impaired elderly women into account when planning future services tailored to this group. In the absence of population-based data generated by large epidemiologic studies, the data presented are the sole basis available for health care planning in Germany. 

Supplementary Materials

Figure sf01, PDF - Figure sf01, PDF 

Footnotes

 Disclosure: R.P. Finger, None; R. Fimmers, None; F.G. Holz, None; H.P.N. Scholl, None

The investigators thank the welfare institution Landschaftsverband Rheinland (LVR) for its continuing support and access to the database, and in particular Jörg Lukas, who made this study possible, and Reena Kunjandy and Mavus Suat, who helped with data collection.