Abnormal Visual Acuity Screening among Secondary Pupils in Owerri Urban.
ABSTRACT
A cross sectional descriptive study of visual acuity if post-primary school children in one urban and one rural community in Owerri were undertaken. A total of 318 children were randomly selected using a multistage sampling procedure.
Out of this number, 170 were males while 208 were females representing 45% and 33% respectively of the study group. The result of the study shows that about 21.4% post-primary school pupils have various degrees of subnormal visual acuity.
Two thirds of these (14% of the total) have mild defects. There is a significant sex variation in prevalence, the female being more affected than the male (14%; 74%).
There appears to be a relationship to height, tall pupils having a higher prevalence than short ones. Similarly, pupils who spend more time in close works has a higher prevalence that those who do not (14.7% and 100%) of those who read between 1 hour to 2 hours and 4 hours to 5 hours respectively.
There is a significant hereditary influence on the incidence of subnormal vision (7.4% and 26.2% of those with negative and positive family history respectively). Eye defect is statistically dependent on family history P = 0.05.
Finally, the population studied presented no data on the age at which myopia commences, but earlier investigations have shown that only a minority are myopic before school age (6 years). After this age, the frequency of myopia increases from year to year.
TABLE OF CONTENT
Title page : : : : : : : : : : i
Declaration : : : : : : : : : : ii
Attestation : : : : : : : : : : iii
Dedication : : : : : : : : : : iv
Acknowledgement : : : : : : : : : v
Content : : : : : : : : : : : vi
List of Tables : : : : : : : : : : viii
List of Figures :: : : : : : : : : ix
Abstract : : : : : : : : : : : x
CHAPTER ONE – INTRODUCTION
1.1 Overview :: : : : : : : : : 1
1.2 Aims and objectives : : : : : : : 3
CHAPTER TWO: LITERATURE REVIEW
2.1 What is visual acuity? : : : : : : : 7
2.2 The structure of the eye and visual pathway : : : 8
2.3 The visual pathway : : : : : : : : 11
2.4 Refractive errors of the eye and amblyopia : : : 12
2.5 Factors affecting visual acuity : : : : : : 16
2.6 Previous investigations on the etiology of myopia : : 19
2.7 Signs and symptoms of eye problems : : : : 24
CHAPTER THREE: METHODOLOGY AND LIMITATIONS
3.1 The study population : : : : : : : 27
3.2 Nature and scope of study : : : : : : 27
3.3 Technique of data collection : : : : : : 28
3.4 Precautions : : : : : : : : : 31
3.5 Limitations of study : : : : : : : 32
CHAPTER FOUR: ANALYSIS AND RESULTS : : : 33
CHAPTER FIVE: DISCUSSION
5.1 General result : : : : : : : : 45
5.2 School variation : : : : : : : 48
5.3 Sex distribution : : : : : : : 49
5.4 Age distribution : : : : : : : 50
5.5 Hereditary influences : : : : : : 52
5.6 Myopia and social class/height : : : : : 54
5.7 Variation with duration of study time : : : : 57
5.8 Symptoms of visual impairment : : : : 59
CHAPTER SIX: CONCLUSION AND RECOMMENDATION
6.1 Conclusion : : : : : : : : 62
6.2 Recommendation : : : : : : : 64
6.3 Areas of further study : : : : : : : 68
References: : : : : : : : : : 70
Appendix : : : : : : : : : : 75
INTRODUCTION
Modern technological developments have brought the replacement of man by machines in a wide range of field and have entailed radical changes in our social structure.
At the same time, the demands made on each individual have increased and even a slight handicap may nowadays limit a man’s opportunities. Defects in visual function are particularly notorious in this regard. Reduced vision limits both possible range of occupations and the exercise of a large number of functions.
Slight myopia is only a slight handicap and may even be an advantage in extensive class work, but higher degrees of myopia is a handicap in every situation, and any attempt to reach a better understanding of the causes of myopia is therefore well-motivated.
Conservative estimated indicate that many school children have important eye troubles. It is helpful to teachers, as well as to lay people, to know the causes and effects of defects in vision. It is helpful to know children’s behavior suggestive of visual difficulties.
Perhaps equally important is the knowledge that some children’s eyes, even after correction with glasses r other methods, may still function less than optimal.
REFERENCES
Anunonye, A: Adaoation To Blindness in Nigeria. Lagos
University Press Lagos, Nigeria. 1981 p. 27.WHO, The Blind Village Onchocrerciasis, Geneva, 1973.
Enahoro, A; Annual Report of the Nigerian Advisory council for
The Blind, Lagos. Gene Government Printer, 1968 Quoted
from Anumonye A; Adaptation to Blindness in Nigeria. p.30.Stogdil, C.G; Schol Achievement. Learning difficulties and
mental health. Canada’s mental Health, supp, 48, 1965
Quoted from Nicholas J.V.V; Vision and learning difficulties
p.375.Nichola, J.V.V; Vision and learning difficulties. The Canadian
Journal of Ophthalmology Vol. 8,1973, p.382.Duke Elder S; system of Ophthalmology Vol. VII: The
Foundations of Ophthalmology; Mosby Company U.S.A., 1962,
p.366.Whyber, K; Ophthalmology 0-The English Language Book
Society and Bailliere Tindall, London, 1979, p.6.Whybar; K; Ophthalmology – The English language Book
Society and Bailliere Tindall, London, 1979, p.6.
StudentsandScholarship Team.
Be the first to comment