Blindness in the Sudan: Prevalence and causes in Blue Nile Province

Bull. Org. niond. Sante 11971, 45, 511-515 Bull. Wld Hlth Org. f Blindness in the Sudan: Prevalence and Causes in Blue Nile Province M. M. 0. BEIRAM1 A survey was carried out in the Blue Nile Province of the Sudan to study the prevalence and causes ofblindness and the possible effect oftraditionalfolk medicine. Blindpeople were examined by ophthalmic assistants and were questioned by a social worker. From the results of the study the overall prevalence of blindness was estimated to be about 660 per 100 000. The main causes of blindness were found to be cataract, anterior segment diseases, glaucoma, trauma, posterior segment diseases, and congenital anomalies. The cataract cases could, however, be correctedfairly easily by surgical intervention. Over 57 % of blind persons had tried traditional folk medicine, 26.4 % had tried modern medicine, and 16.1 % had tried both. Further studies are planned in all provinces of the country. As the occurrence of blindness had not previously been studied in the Sudan, a survey was carried out in the Blue Nile Province from 20 April to 15 June 1969. The Province has 11 towns and 14 rural councils. For the survey 5 towns and 5 rural councils were randomly selected so as adequately to represent the populations of the various parts of the province. The nomads were not surveyed. In 4 of the rural councils, 300 of the villages were surveyed, while in the fifth council 15% of the villages were surveyed. The survey thus covered 350 villages with an estimated population of about 122 300. The five towns included in the study had a total popula- tion of 100 502. The classification of the resident population into age and sex groups was done in accordance with the population structure of the Sudan (UN Department of Economic and Social Affairs, 1964). Survey data were collected by teams each compris- ing two qualified ophthalmic assistants and one social worker. The ophthalmic assistants carried out the eye examinations and the social worker completed a questionnaire for each person examined. The questionnaire was prepared jointly by the Ministry of Health and the Ministry of Social Affairs. To investigate the possibility that traditional folk medicine was a cause of blindness, the survey in- ' Chief, Eye Diseases and Filariasis Division, Ministry of Health, Khartoum, the Sudan. cluded questions relating to the methods blind people had used to treat their eyes. Persons were considered blind if their visual acuity was 3/60 or less. The number of blind persons registered in the study areas was 1 473; of this total, 810 were males and 663 were females (Table 1). Based on the estimated populations the prevalence of blindness was found to be about 860 per 100 000 among the rural popu- lation and about 420 per 100 000 among the urban populations; the overall prevalence of blindness was about 660 per 100 000. The majority of the blind were in the age group 40 years and over; 9.4% were in the 20-39-year age group, 3.7% were in the 10-19-year age group, and 2.40% were in the 0-9-year age group (Table 2). Since it was not possible to establish the exact date of commencement, blindness was classified as having been present since birth or as having commenced during childhood, during adult life or during old age. It was found that 3.2% of the blind persons had been blind since birth, 10.90% had lost their vision during childhood, 9% became blind during their adult life, and that 75.9% became blind during old age. About 1 % of the blind people could not specify the age at which they first became blind. The main causes of blindness were cataract, ante- rior segment diseases, glaucoma, trauma, posterior segment diseases, and congenital conditions in that order of importance (Table 3). Analysis of the data available from those persons with cataract showed that 96.1 % of the cataracts 2746 511 - M. M. 0. BEIRAM Table 1. Prevalence of blindness among the rural and urban populations of the Blue Nile Province, Sudan, 1969 Area Abu Hagar Singa rural councils Sinnar Kosti Rufaa municipal councils (towns) Medani Kosti Rufaa Hassahisa Kamlen total No. of Estimated No. of blind indivi villages population surveyed surveyed Male Female 61 18 544 109 74 73 23 404 86 51 63 21 834 68 66 74 21 830 185 168 79 36 656 116 127 - 47 677 112 70 22 688 84 66 - 9 137 31 27 - 13 000 17 12 - 8000 2 2 222770 810 663 duals Total 183 137 134 353 243 Approximate prevalence in Approximate -Ieach area prevalencepera 0 per 1O00000 987 585 860 614 1 617 663 182 382 150 661 58 635 29 223 4 50 1 473 661 420 were senile, 2.6% were traumatic and 1.20% were cases, while the percentages of secondary glaucoma, congenital. juvenile and congenital glaucoma were 14.3 %, 3.6% The blindness due to anterior segment diseases was and 3.5 %, respectively. attributed to conjunctivitis, trachoma, smallpox, Blindness due to posterior segment diseases was fevers of unknown etiology, measles and diarrhoea in not attributable to a particular disease in 56.1 % of that order of priority. cases, but was attributed to meningitis in 21.0%, dia- Chronic simple glaucoma appears to be the com- betes in 15.8 %, and syphilis in 7.0% of all persons monest type of glaucoma and constituted 78.60% of with posterior segment diseases. Table 2. Age and sex distribution of blind persons in the population surveyed, Blue Nile Province, Sudan, 1969 Survey finding estimated population surveyed no. of blind persons approximate prevalence (per 100 000) estimated population surveyed no. of blind persons approximate prevalence (per 100 000) estimated population surveyed no. of blind persons approximate prevalence (per 100 000) - - - Total 0-9 10-19 20-29 30-39 40-49 > 50 38 317 26 287 18 267 12 475 8 465 8 977 112 788 20 32 44 44 52 618 810 52 122 37 203 25 619 17 22 46 75 520 37 49 86 51 906 54 104 241 17 822 26 146 36 089 70 194 353 12 252 23 188 24 727 67 271 614 8 020 46 574 16 485 98 594 6 884 9 066 529 5 835 18 043 1 147 6 357 718 109 982 663 603 222 770 1 473 661 Sex male female total 1i t_ 512 Aae-arouD (vears) 513BLINDNESS IN THE SUDAN: PREVALENCE AND CAUSES Table 3. Causes of blindness in the Blue Nile Province, Sudan, 1969 cataract anterior segment diseases glaucom; trauma a Causes of blindness senile cataract congenital cataract conju nctivitis trachoma smallpox fevers measles diarrhoeas unknown chronic simple secondary to cataract juvenile congenital meningitis posterior diabetes segment disease syphilis unknown unspecified congenital conditions undetermined total Age group (years) 1 1-9 4 4 1 10 2 4 6 8 33 10-19 120-29 130-39 140-49 2 21 8 5 4 6 1 0 2 4 54 4 10 2 4 10 3 5 10 14 3 4 70 3 10 8 3 3 3 4 14 1 1 3 5 67 20 14 6 6 3 1 9 18 2 13 1 3 98 a Traumatic cataract occurred in 1 6 cases. Analysis of the data showed that the diseases to which blindness was attributed can be grouped as follows: cataract 39.6 , glaucoma 19.4 %, trau- ma 12.20%, unknown 8.4%, conjunctivitis 5.8 %, tra- choma 4.30%, smallpox 3.0%, fevers 2.4%, measles 0.80., meningitis 0.8%, diabetes 0.6%, and syphilis 0.3 /O. The study showed that, of the 1 473 blind persons examined, 846 (57.4 %) persons used traditional folk medicine to treat their blindness, whereas 389 (26.4 %) persons received treatment in hospitals and dispen- saries and 238 (16.1 %) persons tried both traditional folk medicine and modern medical or surgical treat- ment. Of the 1 084 persons who had tried folk medicine, 659 (60.9%) had applied various local medicines, 235 (21.7%) had followed advice and treatment given to them by sheikhs and quacks, and 190 (17.5 %) persons had undergone couching operations to re- move cataract. Over 25% of the persons who had used traditional folk treatment had continued this type of treatment for more than one year. Among the folk medicines used the most common Total > 50 + 553 30 40 32 1 5 3 58 193 39 126 3 8 4 30 3 1 0 1 147 All ages 576 7 86 64 45 36 13 2 80 225 41 10 10 180 12 9 4 32 31 10 1 473 No. 583 326 286 180 57 31 10 1 473 39.6 22.1 19.4 12.2 3.9 2.1 0.7 100 - - 1 M. M. 0. BEIRAM were zinc sulfate, alum, rosaniline and kohl, all ofmin- eral origin; sugar, lemon, and black pepper, all of vege- table origin; and crocodile liver and bile, deer bile, wolf eye, and bone marrow, all of animal origin. The methods applied by sheikhs and quacks included drinking water containing either the ashes of, or par- ticles of, paper on which holy texts had been written, or washing the eyes with such water. In other instances texts from the Koran were read while the blind person's head was held. Cauterization with a piece of red-hot metal was sometimes used in addition. DISCUSSION Ignorance and neglect frequently lead either directly or indirectly to loss of vision in persons suffering from eye diseases. In our survey, 96.3 % of the blind were illiterate. The illiteracy was almost 100% among blind persons in villages and about 94.0% in towns. The incidence of blindness in rural areas was double that found in towns. This difference is not, however, re- lated only to illiteracy. The urban resident usually has a higher living standard, greater health con- sciousness, and easier access to competent medical care than the rural resident. In this study it was found that cataract was the most frequent cause of blindness. Rokos (1969) found the same in Ethiopia, a country that has a common border with the Sudan and with the Blue Nile Pro- vince in particular. Rodger (1959) found senile cata- ract to be one of the four main causes of blindness in Africa, while traumatic and congenital cataracts were less common. In our survey, the latter were found to constitute 3.8 % of all cataract cases while 96.1 % of the cases were of senile cataract. Our studies in different parts of the Sudan have shown that senile cataract occurs in comparatively young per- sons (40-S50 years of age) and that cataract cases account for most of the surgery in eye hospitals. Dhir et al. (1967) suggested that climatic and other environmental factors play an important role in the early development of cataract: they found a corre- lation between the prevalence of cataract and solar radiation. The majority of the residents of the Blue Nile Province, especially those who work in agri- culture, are subjected to intense solar radiation throughout their lives. The incidence of glaucoma among persons over 40 years of age has often been estimated to be about 2% (Holmes, 1961). In our survey glaucoma was found to be the second main cause of blindness (19.4%) and the reasons for such high prevalence are not understood. It is possible that inflammatory conditions of common occurrence in the Sudan, es- pecially those of the anterior segment, increase intra- ocular tension. In this connexion, mass examination and tonometric studies would be of great help, at least in the early detection of cases. Involvement of the anterior segment of the eye was found to be quite common, and the cornea was the site of the lesion in almost all cases. This was not un- expected as the primary lesions frequently resulted from diseases such as conjunctivitis, trachoma, small- pox, and measles. Trachoma is not considered to be a public health problem in this Province, in contrast to the position in the north of the Sudan, yet the disease ranked as the sixth cause of blindness in the Blue Nile Province and the second main cause of lesions of the anterior segment. Kietzman (1968) showed that measles, smallpox, and acute conjuncti- vitis may lead to corneal ulceration or the formation of abscesses that may often cause blindness among children. Budden (cited by Rodger, 1959) found that conjunctivitis, trachoma, cataract, onchocerciasis, and smallpox were among the leading causes of blindness in northern Nigeria. Rodger (1959) analysed the situation in African countries where onchocerciasis was not highly endemic and found that conjunctivitis, trachoma, senile cataract, and smallpox were the most common causes of blindness. Our findings agree in principle with the findings of Rodger and Budden although the occurrence of these diseases is much lower. Our data concerning the role of post-fever complications are in line with those of Rodger. On the other hand our figures for the incidence of cata- ract and glaucoma are much higher. Trauma was most frequently caused by thorns and tree branches. This type of trauma may lead to blindness through development of traumatic cataract and secondary infection. The majority of persons who lost their vision as a complication of smallpox were 50 years of age or older; not a single case of blindness resulting from smallpox was detected in the 0-19-year age group. This observation reflects the overall decrease of smallpox incidence in the Sudan as a result of the eradication programme now in progress. Diseases of the posterior segment of the eye are thought to have contributed to blindness in 3.9% of all the blind persons examined. The main known cause of posterior segment disease was meningitis, which still remains a challenge to the health of the people of the Sudan. Analysis of the causes of blindness by age group shows that in the 0-39-year age group the common- 514 BLINDNESS IN THE SUDAN: PREVALENCE AND CAUSES 515 est causes of blindness were diseases of the anterior segment and trauma, while in persons aged 40 years and over the commonest causes were cataract and glaucoma. It is understandable that a person who loses his eyesight may try any kind of available treatment. However, it was unexpected to find that only 26.4% of blind persons had tried medical treatment alone while 57.4% had relied solely upon traditional folk medicine. This state of affairs is clearly a result of the general low standard of education anid health consciousness of the people and the unavailability of qualified medical care, particularly in the rural areas. In the Sudan, as in other developing countries in Africa, ophthalmic services should be made avail- able to the people near their homes: mobile units should be organized to operate efficiently in the field. In India, the experience of ophthalmic field services has shown that cataract operations can be performed on a large scale in the eye camps with little risk of intraocular infections. The mobile eye units should have facilities for the surgical treatment of trachoma complications such as trichiasis and entropion. Health educators should be attached to the units to raise the health standards of the population and to warn against the harmful effects of some folk medi- cines and techniques. RESUME LA CECITE AU SOUDAN: SA PREVALENCE ET SES CAUSES DANS LA PROVINCE DU NIL BLEU Une enquete sur la prevalence et les causes de la cecite a eu lieu en 1969 dans la Province soudanaise du Nil bleu. Des equipes, comprenant chacune deux ophtalmologistes et un auxiliaire social, ont examine et interroge plus de 220 000 personnes; on a recherche a cette occasion le r6le &ventuel de la medecine traditionnelle dans 1'etiologie de l'infirmite. On a denombre 1473 sujets atteints de cecite, soit une prevalence globale de 6,6 pour 1000. L'affection etait surtout frequente dans le groupe d'age de 40 ans et plus; chez les sujets plus jeunes, les cas se repartissaient comme suit: 20-39 ans: 9,4%; 10-19 ans: 3,7%; 0-9 ans: 2,4%. On a releve comme causes principales, par ordre d'im- portance: la cataracte, les maladies du segment anterieur de l'ceil, le glaucome, les traumatismes, les affections du segment posterieur et les anomalies congenitales. Parmi les aveugles depistes, 57,4% avaient recouru a la medecine traditionnelle, 26,40% avaient ete soignes dans les h6pi- taux et les dispensaires et 16,1 % avaient tate des deux types de traitement. Il est prevu d'etendre ce genre d'investigations a l'en- semble des provinces du pays. REFERENCES Dhir, S. P., Detels, R. & Alexander, E. R. (1967) Amer. J. Ophthal., 64, 1 Holmes, W. J. (1961) Amer. J. Ophthal., 51, 253 International Association for Prevention of Blindness (1937) The number of the blind and the protection of the eye in different countries, Paris Kietzman, B. (1968) Amer. J. Ophthal., 65, 2 Lagraulet, J. & Bard, J. (1947) Bull. Soc. Path. ext., 60, 3 Phillips, C. M. (1961) Centr. Afr. J. Med., 7, 153 Rodger, F. C. (1959) Blindness in West Africa, London, H. K. Lewis & Co. Ltd. Rodger, F. C. (1962) J. Ophthal. Soc., No. 31-32, pp. 7-9 Rokos, L. (1968) E. Afr. med. J., 45, 407 Scott, G. I. (1950) Memorandum on a visit to W. Africa (cited by Rodger, 1959) Sorsby, A. (1950) The incidence and causes of blindness; an international survey, London, British Medical Asso- ciation (Brit. J. Ophthal., Monograph Supplement XIV) UN Department of Economic and Social Affairs (1964) Population growth and manpower in the Sudan; a joint study by the United Nations and the Government of the Sudan, New York, United Nations (UN document ST/SOA/Series A/37) Waddy, B. B. (1949) Onchocerciasis and blindness in the Northern Territories, Official Report to D.M.S., Accra Waddy, B. B. (1954) Results reported by Rodger (1959)