Predictors Of Visual Impairment Research Articles

Visual impairment and its predictors among people living with type 2 diabetes mellitus at Dessie town hospitals, Northeast Ethiopia: institution-based cross-sectional study

BackgroundVisual impairment is a functional limitation of the eye(s) that results in reduced visual acuity, visual field loss, visual distortion, perceptual difficulties, or any combination of the above. Type 2 diabetes mellitus is one of the common causes of visual impairment. Since there is no study conducted in Ethiopia so far in this regard, the current study aimed to determine the prevalence and predictors of visual impairment among people living with diabetes at Dessie town Hospitals, Northeast Ethiopia.MethodsInstitution based cross-sectional study was carried out from 15 February to 15 March 2020 using simple random sampling to recruit study participants among type 2 diabetes. Visual impairment was measured using visual acuity test. We used Epi Data 3.1 and SPSS version 22 for data entry and statistical analysis, respectively. Bi-variable binary logistic regression was performed to check independent association of each factor with visual impairment. After selecting candidate variables at p < 0.25, we computed multivariable binary logistic regression to identify statistically associated factors of visual impairment. The degree of association was determined using adjusted odds ratio with 95%CI. In the final model, statistical significance was declared at p < 0.05.ResultsThree hundred and twenty-two people living with T2DM participated in this study with 97% response rate. The prevalence of visual impairment was 37.58% (95% CI: 32.3, 42.9). Age (AOR: 1.06, 95% CI: 1.02, 1.09, p < or = 0.001), poor regular exercise (AOR = 2.91, 95%CI: 1.47–5.76, p < or = 0.001), duration of DM above 5 years (AOR = 2.42, 95% CI: 1.25–4.73, p < or = 0.01), insulin treatment (AOR = 14.05, 95% CI: 2.72, 72.35, p < or = 0.01), and poor glycemic control (AOR = 2.17, 95% CI: 1.13–4.14, p < 0.05) were statistically associated with visual impairment.ConclusionThe prevalence of visual impairment in Dessie town hospitals accounted for more than a third of patients living with T2DM. Visual impairment is associated with increased age, poor regular exercise, longer duration of DM, and insulin treatment. Thus, early detection of VI through screening and regular follow-up is recommended to reduce the risk of VI and vision loss.

Predictor of Visual Impairment Following Paraclinoid Aneurysm Surgery: Special Consideration of Surgical Microanatomy Related to Paraclinoid Structures.

Microsurgical clipping with extradural anterior clinoidectomy (EDAC) for paraclinoid aneurysm is an established technique with good angiographic outcomes, although postoperative worsening of visual acuity remains a concern. Multiple reports show visual acuity deteriorating after clipping, yet the cause remains unclear. To analyze results of asymptomatic paraclinoid aneurysm surgeries treated with EDACs, specifically focusing on the microanatomy of paraclinoid structure dissection. This determined the causes of delayed visual impairment and microsurgical indications. Results of the treatment with EDAC of 94 patients with cerebral aneurysm and normal preoperative visual acuity but also full visual fields were retrospectively analyzed. The mean aneurysm size was 6.2 (±3.3) mm. Clipping was performed in 87 cases and trapping in 7 cases. Complete angiographic occlusion was observed in 91 patients. In 26 cases, a postoperative visual deficit occurred. A total of 20 cases exhibited partial visual field deficits, including 5 who were asymptomatic. Visual deficits were only detectable by postoperative ophthalmologic testing. Six showed light perception impairment or blinding. Of the 15 patients with symptomatic partial visual field deficits, 5 showed improvement at follow-up. Visual deficits persisted in 22 patients at the last follow-up. Multivariate logistic regression analysis revealed that medial projecting aneurysm (adjusted odds ratio [OR]: 10.43) and the opening of the carotidoculomotor membrane (adjusted OR: 5.19) were significantly related to visual impairment. Excess dissection of carotidoculomotor membranes causes postoperative delayed visual worsening. For treating small, asymptomatic paraclinoid aneurysms, carotidoculomotor membranes should not be opened, and microsurgical clipping should not be performed for preoperative asymptomatic medial projecting aneurysms.

Visual cortex changes in children with sickle cell disease and normal visual acuity: a multimodal magnetic resonance imaging study.

The visual system is primarily affected in sickle cell disease (SCD), and eye examination is recommended starting in late childhood. So far, to our knowledge, all studies have focused on the retina, neglecting the changes that might be present in the cortical portion of the visual system. We performed a multimodal magnetic resonance imaging (MRI) evaluation of the visual cortex in 25 children with SCD (mean age: 12·3±1·9 years) and 31 controls (mean age: 12·7±1·6 years). At ophthalmologic examination, 3/25 SCD children had mild visual acuity deficits and 2/25 had mild tortuosity of the retinal vessels. None showed optic pathway infarcts at MRI or Transcranial Doppler abnormal blood velocities, and 6/25 disclosed posterior cerebral artery stenosis (five mild and one severe) at MR-angiography. Compared to controls, SCD children had increased posterior pericalcarine cortical thickness, with a different trajectory of cortical maturation and decreased connectivity within medial and ventral visual neural networks. Our findings suggest that SCD affects the development and the tuning of the visual cortex, leading to anatomical and functional changes in childhood even in the absence of retinopathy, and set the basis for future studies to determine if these changes can represent useful predictors of visual impairment in adulthood, biomarkers of disease progression or treatment response.

Prevalence and determinants of visual impairment amongst school-aged children in Southern Nigeria

Background: Visual impairment among school children is relatively common and research provides evidence for integration of comprehensive eye care into school health programmes. Aim: To determine the prevalence and determinants of visual impairment in school-aged children in Southern Nigeria. Setting: School aged children from 10 public and private-owned schools in Cross River State, Southern Nigeria. Methods: This cross-sectional analytic study used a multistage random sampling technique to select 2418 school children aged 6–17 years. Comprehensive eye examinations were performed on the study. The logistic regression analysis with 95% confidence interval (CI) was used to test hypotheses. Results: Of the 2418 school children selected, 2110 (87%) were assessed. The prevalence ‘of uncorrected, presenting and best corrected visual acuity of 0.3 (20/40) or worse in the better eye’ was 7.3%, 7.2% and 0.19%, respectively. Errors of refraction were the cause of the impairment in 198 (70.7%; 63.5–76.0) eyes with reduced vision, followed by glaucoma suspects 38 (19.2%; 13.8–24.8), amblyopia (3.0%; 1.1–6.4) and corneal opacity 3 (1.5%; 0.3–4.3). The major and independent predictors of visual impairment were age (adjusted odds ratio [AOR] 1.97, 95% 1.45–2.67), high socio-economic status (adjusted odds ratio [AOR] 1.68, 95% 1.36–2.09) and female gender (AOR 1.35, 95% 1.00–1.88). Conclusion: The common causes of visual impairment in school-aged children are avoidable, and are mostly because of uncorrected refractive error, which could reflect inadequate refractive error services in the area.

Predictors of visual impairment in primary and secondary glaucoma in a tertiary institute in North India.

To find out and compare various predictors of glaucoma-related visual impairments in primary and secondary glaucoma. A prospective observational study of patients, who were above 30 years of age. They were diagnosed as primary/secondary glaucoma with visual acuity <20/200 Snellen's/visual field showing less than 20° isopter in at least one eye, with a minimum follow-up of one year at a tertiary center. Patients were classified into advanced and end-stage glaucoma and outcome was assessed according to visual acuity and visual fields to see predictors of visual impairments. There were 169 (99 primary/70 secondary) glaucoma patients with mean age of 62.67 ± 11.9 and 54.65 ± 15.26 years, respectively. Trauma (21.4%), complicated cataract surgery (15.7%), and silicon oil tamponade (14.3%) were common causes of secondary glaucoma. There was significant delay in diagnosis in primary compared to secondary glaucoma (57.57% vs 32.85%) and non-compliance was significantly higher in primary glaucoma (34.3% vs 17.1%, p = 0.01). In univariate analysis, literacy, income status, locality, and delayed or missed diagnosis were found to be significant (p < 0.05) according to visual acuity criteria. Out of the 33 patients who had undergone glaucoma filtration surgery, 18 (54.5%) were in the end-stage group. While 105 (77.2%) of 136 patients who were not subjected to any glaucoma filtration surgery reached end-stage glaucoma as per visual fields criteria (p = 0.011). Lack of awareness, delayed diagnosis, low literacy, and income were associated with poor visual outcome. Patients who underwent glaucoma filtration surgery had significantly better visual outcome in comparison to patients managed medically.

Burden, etiology and predictors of visual impairment among children attending Mulago National Referral Hospital eye clinic, Uganda.

Childhood visual impairment (CVI) has not been given due attention. Knowledge of CVI is important in planning preventive measures. The aim of this study was determine the prevalence, etiology and the factors associated with childhood visual impairment among the children attending the eye clinic in Mulago National Referral Hospital. This was a cross sectional hospital based study among 318 children attending the Mulago Hospital eye clinic between January 2015 to March 2015. Ocular and general history was taken and patient examination done. The data generated was entered by Epidata and analyzed by STATA 12. The prevalence of CVI was 42.14%, 134 patients with 49 patients (15.41%) having moderate visual impairment, 45 patients (14.15%) having severe visual impairment and 40 patients (12.58%) presenting with blindness. Significant predictors included; increasing age, delayed developmental milestones and having abnormal corneal, refractive and fundus findings. There is a high burden of visual impairment among children in Uganda. It is vital to screen all the children presenting to hospital for visual impairment. Majority of the causes of the visual impairment are preventable.

Visual Impairment in HIV Negative Tuberculosis Meningitis

Objective: Visual impairment is a common problem in tuberculous meningitis (TBM). Present study has been conducted to evaluate the prevalence of visual impairment at presentation and at 3 months. Methods: Twenty seven consecutive HIV negative patients with TBM were included. Visual acuity, colour vision, field of vision, and visual evoked potentials (VEP) were recorded at baseline and at 3 months. The criteria for visual impairment were: visual acuity <6/12 and <N/10, defective color vision, and visual field abnormality either alone / in combination. Fundus was examined by a single examiner using slit lamp biomicroscopic examination with 90 D lens and by indirect ophthalmoscopy with 2.2D lens. Results: Twelve patients out of 27 had visual impairment at presentation and the causes were optochiasmatic arachnoiditis (n=6), optic atrophy (n=2), occipital infarct (n=1) and unremarkable (n=3). Three patients showed improvement in visual acuity, 6 patients had no change and 3 patients expired at 3 months. On multivariate analysis papilloedema, optic atophy, temporal disc pallor and hydrocephalus were predictors of visual impairment at 3months (p< 0.001 ). Conclusion: Visual impairment in TBM is observed in half the patients. It may be predicted by the presence of hydrocephalus on computerized tomography (CT)/ magnetic resonance imaging (MRI), while a simple bedside fundus examination can predict the visual impairment at three months. VEP helps in detecting sub-clinical visual impairment.

Abstract 15681: Endothelial Dysfunction, Arterial Stiffness and Inflammation Are Associated With Visual Impairment in Diabetic Patients

Introduction: Diabetic Retinopathy (DR) is a complication of diabetes mellitus (DM) leading to deterioration of vision. Hypothesis: We investigated the possible association of vascular function and inflammation with visual acuity in subjects with DM. Methods: We enrolled 100 consecutive subjects with DM. Patients were divided in those with DR (53 subjects, mean age 68±9) and those with no evidence of DR (NDR) (mean age 66±6). The diagnosis of DR was made by ophthalmoscopy and best-corrected visual acuity (BCVA) was measured in both eyes. A BCVA less than 0.8 was considered as severely impaired. Endothelial function was evaluated by flow mediated dilation (FMD) in the brachial artery and arterial stiffness was evaluated by carotid femoral pulse wave velocity (PWV). C reactive protein (CRP) and interleukin 6 (IL6) levels were measured. Results: Patients with DR compared to NDR patients had impaired FMD (3.42±1.08% vs. 5.39±1.47%, p&lt;0.001), impaired PWV (11.10±3.11m/sec vs. 9.02±2.13m/sec, p=0.001) and worse BCVA (p&lt;0.001). Moreover in DM subjects, BCVA was positively correlated with FMD, creatinine clearance, and inversely correlated with PWV, glycosylated hemoglobin levels, C- reactive protein levels, IL6 levels, age and with duration of diabetes mellitus (p&lt;0.01 for all). Interestingly, after adjustment for age, smoking habits and the aforementioned confounders, FMD, IL6 levels, DM duration and male gender were independently associated with BCVA (p&lt;0.05 for all). Moreover, ROC curve analysis revealed that both impaired FMD (AUC=0.79, p&lt;0.001) and PWV (AUC=0.8, p&lt;0.001) have a significant diagnostic ability in detecting diabetic subjects with severely impaired BCVA. More precisely, FMD less than 4.5% has a sensitivity of 90% and a specificity of 60%, while PWV over 10.0 m/sec has a sensitivity of 83% and a specificity of 68%, for the diagnosis of severely impaired BCVA. Conclusion: Patients with DR have significantly impaired visual acuity witch is associated with impaired vascular function and inflammation. Moreover, both endothelial function and arterial stiffness were high sensitivity predictors of visual impairment highlighting their potential role on the prevention and management of the complications in diabetes mellitus.

Highly Reflective Foveal Region in Optical Coherence Tomography in Eyes with Vitreomacular Traction or Epiretinal Membrane

To report the optical coherence tomography (OCT) findings in eyes with vitreomacular traction (VMT) or with an epiretinal membrane (ERM). Retrospective case series. Fifty-four eyes of 45 consecutive patients with subjective visual disturbances resulting from VMT or idiopathic ERM were studied. The morphologic features of the photoreceptor layer at the foveal center were determined and the central foveal thickness (CFT) was measured by spectral-domain (SD) OCT. The morphologic characteristics of the foveal region observed by SD OCT. A roundish or diffuse highly reflective region was observed between the photoreceptor inner segment/outer segment junction line and the cone outer segment tip line at the center of the fovea. This highly reflective region was present in 7 of 7 cases of VMT and 30 of 47 cases of ERM. In the ERM cases, the mean CFT of the cases with the highly reflective region was significantly thicker than that in cases without it. The highly reflective region disappeared when the inward traction on the fovea was released surgically or spontaneously. The highly reflective region is a characteristic sign observed in the OCT images of eyes with VMT and ERM, and it has been termed the cotton ball sign after its appearance. The presence of the cotton ball sign indicates an inward traction on the fovea and may be a predictor of visual impairment.

Disability and 6-year mortality in elderly population. Role of visual impairment

We investigated the prevalence of visual impairment (VI), its determinants and its association with Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), Gross Mobility (GM) and 6-year mortality in elderly subjects. A cross-sectional survey in a large population randomly selected in 1992 with a 6-year mortality evaluation in Campania, a region in southern Italy. A random sample of 1332 elderly subjects aged 65 to 95 years (mean age 74.2 +/- 6.4), selected from the electoral rolls, was interviewed by trained physicians. Self-reported visual function, socio-demographic and clinical characteristics were recorded. Disability was assessed by measuring ability in ADL, IADL and GM. VI was found to affect 34% of this population, with an age-related increase of mild and severe VI. VI affects ADL, IADL and GM disability. Age, diabetes and low educational level, but not comorbidity or hypertension, proved to be predictors of VI. Mortality increased with severity of VI in 38.1% of subjects with severe functional impairment (p < 0.001). The presence of VI was seen to increase the risk of mortality by 1.40 (95% CI 1.07-1.84), independently of age, sex, comorbidity, diabetes, hypertension or disability. This study demonstrates an association between visual impairment and disability in an elderly population, and the predictive effect of visual impairment on mortality independently of comorbidity. These results illustrate the need to eradicate avoidable blindness, in order to improve the quality of life and to prolong survival of the elderly.

The Houston Vision Assessment Test (HVAT): an assessment of validity

PURPOSE. Cataract surgery is one of the most successful procedures in medicine, and outcome is typically measured by a single factor – improvement in visual acuity. Health-related functional outcome testing, which quantifies the patient's self-reported perception of impairment, can be integrated with objective clinical findings. Based on the patient's self-assessed lifestyle impairment, the physician and patient together can make an informed decision on the treatment that is most likely to benefit the patient. METHOD. A functional outcome test (the Houston Vision Assessment Test – HVAT, copyrighted 1990, 1992) was evaluated in a cataract population of 149 patients from seven study centers. Test results were correlated with objective ophthalmic endpoints. The HVAT divides an estimated total impairment into subcomponents of Visual Impairment (correctable by cataract surgery) and non-visual Physical Impairments (co-morbidities not affected by cataract surgery). RESULTS. In this prospective study, the average Visual Impairment score improved by 19 points (65%) following cataract extraction (the mean HVAT Visual Impairment score was 29 points before surgery and 10 points at 5 months post-surgery, a change of 65%). Physical Impairment remained unchanged by surgery. Visual acuity was a poor predictor of Visual Impairment. CONCLUSIONS. The HVAT has 11 simple questions. It may be self-administered and is available on the Internet: http://www.DHAC.com. The physician may err if his decision in favor of cataract surgery is based only on visual acuity. The HVAT has the potential to guide the decision-making process between patient and physician.

Visual function in full-term infants with hypoxic-ischaemic encephalopathy.

Thirty-one full term infants with hypoxic-ischaemic encephalopathy (HIE) were studied with a battery of tests designed to evaluate visual function in infancy and with serial MRI. Their age ranged between 5 and 31 months. The aim of the study was to evaluate whether the degree of HIE or the site and size of lesions on MRI could predict visual outcome. Twenty of the 31 infants studied showed abnormal results on at least one of the visual tests used. While visual function was generally normal in grade I HIE and severely impaired in grade III, visual outcome was variable in grade II. MRI findings were better predictors of visual impairment than the degree of HIE. Normal scans tended to be associated with normal visual function, irrespective of the severity of HIE. All but one of the infants with diffuse hemispheric involvement also showed multiple visual abnormalities. The concomitant involvement of basal ganglia was always associated with more severe visual outcome. These results suggest that infants with generalised lesions secondary to global insults are at high risk of severe visual impairment even in presence of normal acuity and require early assessment of various aspects of visual function.