Prevalence of ocular morbidity among inmates.
In this study, the prevalence of ocular morbidity was 49% among inmates which was high compared to previously reported studies of inmates in Nigeria (26.8%). [15] The difference could have been due to age differences with Nigeria study reporting a mean age of 27.2 years. The tendency of ocular morbidity to occur increases at around 40 years of age and further shows a steep increase after the age of 60 years. [16] It was also noted that inmates from other prisons would be referred to Luzira prison for various reasons some being medical, overcrowding in other prisons or completion of their sentences. This could also probably account for the high ocular morbidity in our study. In a similar study done in Ilesa prison Osun state, mean age of inmates was 32 years and prevalence was 69.7%. [8] This was high in comparison to this study. This could be due to difference in environmental factors. Osun state is situated in a tropical rain forest zone and experiences winter and summer. In comparison to non-incarcerated populations, inmates are known to have elevated rates of morbidities. [17]
In a population-based study done on rural adults in southwest Uganda, the prevalence of ocular conditions was found to be 9%. [18] This was low in comparison to this study. These findings would be due to the fact that the study noted only nonvisual impairing conditions and left out the blinding conditions. There are no similar studies like this one among the general population in Uganda.
Similarly, to other studies [7, 15, 19], Presbyopia, Allergic conjunctivitis, Refractive errors, Cataracts and Vitamin A deficiency were among the most common ocular morbidities. Presbyopia was found in 27.4% of the inmates. This prevalence is comparable though higher than a similar study in inmates which found presbyopia in 21.5%. [15] In Ilesa prison Nigeria had a lower prevalence of 10.9% [8] in comparison to our study. This could be because most of the inmates in Ilesa were in 21-30-year age group. Presbyopia is a physiological change associated with ageing. The expected age of onset is 40 years with incidence increasing with age [4] which explains the higher prevalence in this study where more than 50% were aged 40 and above. Identification of such inmates with presbyopia and providing them with reading glasses will be useful in rehabilitating them and also help them in performing near tasks.
Allergic conjunctivitis was the second commonest morbidity with a prevalence of 19.6% and was comparable to studies done elsewhere [7, 8, 15, 18]. Prisons tend to have similar conditions overcrowding and dusty. Ilesa prison is reported to be smoky. Allergic conjunctivitis is associated with a lot of discomfort.
Cataracts were found in 23 inmates accounting for 10.9% prevalence which is high in comparison to studies done among Nigerian inmates where prevalence was 5.7% [15] and 4.9%. [8] However the inmates in Nigeria had a mean age of 27.6 and 32 years respectively and cataract incidence increases with age. In our study we also found a higher number in trauma cases which could also explain increase of the cataracts(traumatic). Cataracts are some of the leading causes of treatable blindness.
The global initiative for elimination of avoidable blindness (VISION 2020) has recognized refractive errors as a major cause of visual disability. The prevalence of refractive errors was 8.7% and this was comparable to a study done in south western Uganda, [19] where 12.3% of the refractive errors inmates had refractive errors. Provision of eye glasses will go a long way in alleviating symptoms.
In comparison to earlier studies done in both southwestern Uganda (35%) and Kenya (23.6%) [19, 20], prevalence of Vitamin A deficiency was low (4.6%). This could be due to the fact that inmates in Luzira prison were routinely given vitamin A supplements and also perhaps due to additional meals that some inmates have.
The prevalence of glaucoma among inmates was 0.9% and this was comparable to the prevalence of a study done in Mbarara prison. 0.4%. [19] Studies done on prevalence of glaucoma at Mulago National Referral hospital and Ruharo Eye hospital were found to be high, 26.1% and 64.2% respectively [21]. These prevalences are much higher than in our study probably due to the fact that Mulago and Ruharo were hospital based studies with possible referral bias. In this study 2 of the inmates had advanced glaucoma. However, they had never had anti-glaucoma treatment. This creates a great danger as there is irreversible visual field loss when glaucoma remains untreated. [22]
Optic atrophy, Corneal scars, dry eye syndrome, uveitis, macular scars, were documented in these inmates. Any of the above conditions may be associated with marked visual impairment especially when there are poor ophthalmic facilities.
Factors associated with ocular morbidity
In this study, the factors that were significantly associated with ocular morbidity among the inmates included: age, trauma and eating non prison food.
From this study, the older inmates (> 50 years) were about 12 times more likely to have an ocular morbidity. (OR = 11.96, P-value = 0.001) than those aged 18–30 years. This correlates with findings in the study on pattern of ocular morbidity in an elderly population. The study showed a relationship between increasing age and ocular morbidity. This could be due to the physiological changes that happen with aging. Incidence of disease like presbyopia, cataracts, dry eye syndrome increases with age. [1]
Inmates with a history of trauma were five times more likely to have an ocular morbidity (OR = 5.21, P-value = 0.009). A study was done on ocular injuries in patients with major trauma and it was reported that the risk of an eye injury with a facial fracture was 6.7 times as that for a patient with no facial fracture. [23] Inmates are likely to incur trauma when out in the fields, fights with fellow inmates or possibly when being given a punishment or even in the process of arrest or mob justice. Untimely and improper management can lead to visual impairing complications. In a study done in USA, 16% of the inmates experienced ocular trauma (p < 0.001) and 1.2% had open globe injury (p = 0.06), requiring surgical intervention. [24]
Inmates who had other foods besides prison food were less likely to have an ocular morbidity. (OR = 0.45, P-value = 0.006) This could be because they were having foods rich in vitamin A, energy foods, body building foods that help in normal bodily functioning. A study done in Haiti among inmates noted that those who did not receive additional food from visitors, were at increased risk of poor nutritional status and physical health. [17]
In this study, HIV was not statistically significant. In a study done by Pathai et el showed that a low CD4 count (< 100 cells/ul and WHO clinical stages 3 and 4 were associated with increased odds of having an ocular morbidity. [25] This low CD4 count predisposes them to many opportunistic infections. However, in Luzira all inmates on arrival are screened, counseled and started on anti-retroviral if found positive. This has reduced the incidence of some of the opportunistic infections.
Study limitations:
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Selection bias as some inmates were in solitary confinement and could not assessed for the study.
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Information bias as some inmates were scared to give information for example in cases of torture or assault.
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Being a cross sectional study, the ocular disorders found during this season may not be the ones found in other climatic conditions.