Annals of African Medicine Vol. 3, No. 4; 2004: 185 – 187 PATTERN OF CORNEAL OPACITY IN IBADAN, NIGERIA

A. O. Ashaye and T. S. Oluleye

Department of , University College Hospital, Ibadan, Nigeria Reprint requests to: A. O. Ashaye, Department of Ophthalmology, University College Hospital, Ibadan, Nigeria

Abstract Background: The prevalence and causes of corneal blindness vary from one region of the world to another. There is even variation within the developing countries of Africa. Method: A retrospective review of 675 patients with corneal scarring out of the 3,753 new patients corneal scarring in patients attending the eye clinic of the University College Hospital (UCH) Ibadan over a 5year period. Results: Subjects in age groups 0 to 10years and 21 to 30years were mostly affected. Males were more affected with a ratio of 3:1. Most presentations were in the months of January to March and July to September. Almost half (48.99%) of the patients had uniocular blindness and no case of bilateral blindness from corneal opacity was found. The main causes of corneal opacity were trauma (51.1%) and microbial (26.70%) both of which are avoidable causes of blindness. No case of trachomatous corneal scarring was found in the group studied. Conclusion:

Key words: , opacity, blindness

Introduction opacity in the south western part of Nigeria. As a preliminary to community based study to identify the The cornea is exposed to the atmosphere and so often relative importance of known causes of corneal suffers injury, inflammation or infection. Corneal blindness as seen in the south western part of Nigeria, opacity results from a process, which upset its the aetiology of cases seen in hospital was anatomy and physiology. Because the cornea is such determined. a specialized structure, any inflammation or injury is likely to cause some permanent damage or scar. The scar tissue is white and opaque, while healthy corneal Patients and Methods tissue is transparent. Corneal disease is common in the tropics1 and in developing countries. Indeed the A retrospective review of cases with diagnosis of prevalence of corneal scar in any community is a corneal opacity attending the eye clinic of the good indication of the general health, hygiene and University College Hospital, Ibadan, Nigeria between nutrition of that community. 1 1996 and 2000 was carried out. Such cases would Corneal scar is a leading cause of blindness in have been referred from various clinics within and Africa after and . 2 Corneal scar outside this teaching hospital such as paediatric from measles, , the use of outpatient and children emergency room. Information harmful traditional eye medications and ophthalmia sought included, age at presentation, sex, time of neonatorum are the major causes of blindness in presentation visual acuity, and aetiology of corneal children in low-income countries. 3 scar. Statistical analyses were done, using Ocular trauma and corneal ulceration are proportions and percentages to summarize the data. significant causes of corneal blindness that are often underreported, but may be responsible for 1.5 – 2.0 million new cases of monocular blindness yearly. 4 Results The prevalence and causes of corneal blindness vary from one region of the world to another. There There were 3,573 new patients seen in the eye clinic is also variation within the developing countries of of University College Hospital Ibadan (UCH) during Africa. Environment and availability of ophthalmic this period of which 675 subjects (18.9%) had corneal services and general health care are factors that opacity. The peak age of presentation was 0 – 10 contribute to this variation. 5 years (46.7%) (Table 1). The periods of January to No community-based studies have been done to March, and July to September were noted to be the determine the prevalence and causes of corneal peak periods of presentation (Table 2). Trauma

186 Pattern of corneal opacity. Ashaye A. O. and Ollie T. S.

(51.1%), microbial keratitis (26.7%) and vitamin A increase in the incidence of measles while the second deficiency (8.9%) were the main causes of corneal peak coincides with the harvesting season when opacity. Other causes found were viral keratitis, farmers are likely to get injured on the farm. The dry exposure keratitis, and other less frequent causes like season presentations suggest an increase in incidence opacity following surgery, and vernal of corneal disease from vitamin A deficiency disease. (Table 3). Almost half (48.9%) of the No case of bilateral blindness was found in the eyes with corneal opacity seen in this study were study. Corneal blindness is often underreported but blind that is, had visual acuity less than 3/60 after may be responsible for 1.5 - 2.0million new cases of treatment. monocular blindness every year. 4 In Kenya, Tanzania9 and Sudan10 corneal opacity from was a major cause of low vision and Table 1: Age of presentation of corneal opacity in blindness. In the present study trauma is a major University College hospital, Ibadan, 1996 – 2000 cause of corneal opacity. There is a suggestion that trauma and microbial keratitis are important causes of Age No. % corneal opacity in patients seen in this hospital, which 0 –10 315 46.7 serve a predominant agricultural population. 8 11 – 20 30 4.4 It was found in Nepal that the most common 21 – 30 150 22.2 cause of corneal ulceration was trauma. Gara and Rao 31 – 40 75 11.1 in India found that corneal infections are responsible 40+ 105 15.6 for a large proportion of corneal scar and that corneal Total 675 100.0 scar was the most common indication (28.1%) for , of which keratitis accounted 11 for 50.5%. In Botswana, corneal opacity was Table 2: Month of presentation of corneal opacity in reported to be the second most common cause of unilateral and third leading cause of bilateral University College Hospital, Ibadan, 1996 – 2000 12 blindness. In Nigeria, Nwosu found that trauma predispose to Month No. % uniocular blindness13 and , while in January – March 240 35.6 the Gambia, 14 non-trachomatous corneal opacity and April – June 90 13.3 phthysis bulbi cause about 20% of blindness. WHO, July – September 285 42.2 15 Waddell16 and O’Sullivan et al, 17 reported that in October - December 60 8.9 children, xerophthamia, ophthalmia neonatorum and Total 675 100 less frequently herpes simplex infection and viral kerato conjunctivitis are responsible for corneal blindness. The use of traditional eye medicines is a Table 3: Aetiology of corneal opacity in University major risk factor in the current epidemic of corneal College hospital, Ibadan, 1996 – 2000 ulceration in developing countries. 18 Because of the difficulty of treating corneal Aetiology No. % blindness once it has occurred, public health Trauma 345 51.2 prevention programmes are the most cost-effective Microbial keratitis 180 26.7 means of decreasing the global burden of corneal Vitamin A deficiency 60 8.9 blindness3. There is a need for communities based Viral 30 4.4 study on the aetiology of corneal opacity and plan a Exposure keratitis 15 2.2 programme for prevention of the major causes. Congenital 15 2.2 Others 30 4.4 Total 675 100 References

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