Evaluation of risk factors for advanced glaucoma in Ghanaian patients

Differentiating stages of functional vision loss from glaucoma using the Disc Damage Likelihood Scale and cup:disc ratio

BACKGROUND

Glaucoma staging is critical for treatment planning but has rarely been tested in severe/end-stage disease. We compared the performance of the Disc Damage Likelihood Scale (DDLS) and cup:disc ratio (CDR) using a functional glaucoma staging system (GSS) as the reference standard.

METHODS

Post hoc analysis of a randomised controlled trial at the Eye Department of Kilimanjaro Christian Medical Centre, Tanzania. Eligible participants (aged ≥18 years) with open-angle glaucoma, intraocular pressure (IOP) of >21 mm Hg, were randomised to timolol 0.5% eye drops or selective laser trabeculoplasty. Fundoscopy established vertical and horizontal CDRs and DDLS. Visual acuity and static visual fields were graded (GSS). The study used area under the receiver operating characteristic (AROC) curves and Spearman's rank correlation coefficients to compare staging systems. Logistic regression with generalised estimating equations determined risk factors of functional severe/end-stage glaucoma.

RESULTS

382 eyes (201 participants) were evaluated; 195 (51%) had severe or end-stage glaucoma; mean IOP was 26.7 (SD 6.9) mm Hg. DDLS yielded an AROC of 0.90 (95% CI 0.87 to 0.93), vertical cup:disc ratio (vCDR) of 0.88 (95% CI 0.85 to 0.91, p=0.048) for identifying severe/end-stage disease. Correlation coefficients comparing GSS to DDLS and vCDRs were 0.73 and 0.71, respectively. Advanced structural stages, vision impairment, higher IOP and less financial resources were risk factors of functional severe/end-stage glaucoma.

CONCLUSION

This study indicates that both structural staging systems can differentiate severe/end-stage glaucoma from less severe disease, with a moderate advantage of DDLS over CDR. Clinical examination of the optic disc plays an important role in addition to functional assessment when managing severe/end-stage glaucoma.

Cataract Surgery Visual Outcome and Associated Factors Among Adults Attended Jimma University Medical Center, Jimma, Southwest Ethiopia

Background

Cataract is the leading cause of blindness and the second leading cause of visual impairment worldwide, accounting for 51% and 33% of all cases, respectively, in low- and medium-income countries bearing a disproportionately high burden. Hence, this study aimed to assess the visual outcome of age-related cataract surgery and identify factors associated with patients' postoperative visual outcomes in Jimma University Medical Center, Southwest Ethiopia.

Methods

An institution-based cross-sectional study design was conducted among 386 cataract surgery patients from January 1, 2016, to December 30, 2017. The study participants were selected using a systematic random sampling technique. Data were collected by reviewing the selected patients' medical records using a pre-tested checklist, entered into EpiData version 3.1, and exported to SPSS 20 for analysis. Proportions, summary statistics, and tables were used for presentations of the findings. Binary logistic regression was carried out to identify independent predictors of visual outcome. Findings were presented with adjusted odds ratios and their 95% confidence interval. A p-value <0.05 was used to declare a statistically significant association.

Results

About 231 individuals (59.8%) had poor visual results following cataract surgery. Furthermore, age >70 (AOR = 3.64; 95% CI [1.35-9.82]), preoperative ocular co-morbidities (AOR = 2.34; [1.32-4.15]), incision-based cataract surgery (AOR = 7.11; [3.16-16.02]), compared phacoemulsification operated by resident surgeons (AOR = 2.19; [1.23-3.89]), presence of intraoperative complication (AOR = 3.41; [1.47-7.92]), lens remnant (AOR = 2.91; [1.11-4.92]), ocular inflammation (OR = 2.56; [1.34-4.92]), and striate keratopathy/corneal edema (AOR = 1.91; [1.07-3.44]) were significantly associated with poor visual outcome.

Conclusion

The visual outcome following cataract surgery fall below WHO recommendation. In this study, age, ocular co-morbidities, surgical method, surgeon status, intraoperative complication, SK, and ocular inflammation associated with post-operative Uveitis and anterior chamber reaction were associated with a poor visual outcome.

Determinants for late presentation of glaucoma among adult glaucomatous patients in University of Gondar Comprehensive Specialized Hospital. Case-control study

Introduction

Glaucoma is a disease which causes optic nerve damage and remains a major public health concern worldwide. Late presentation is a major risk factor for glaucoma induced blindness. The aim of this study was to assess determinants for late presentation of glaucoma among adult glaucomatous patients.

Methods

A hospital-based case-control study was conducted among 452 adult glaucomatous patients. Late presenters were glaucoma patients diagnosed with cup to disc ratio (CDR) > 0.8 and mean deviation of greater than -14 decibel in either of the eyes at their first presentation. Study participants were selected among glaucomatous follow-up patients by using systematic random sampling. Data were entered into EPI Info version 7 and exported to SPSS version 22 for analysis. Bivariable and multivariable logistic regression analysis was done to identify determinants. Variables with P-value < 0.05 were considered as statistically significant.

Result

The mean age of participants were 55.1 ± 13.2 years. Being > 60 years of age, 4.51 times (AOR: 4.51; 95% CI: 1.74, 11.67), resided > 53 km away from the hospital 6.02 times (AOR: 6.02; 2.76, 13.14), Presenting IOP > 30 mmHg, 4.49 times (AOR: 4.49, 95% CI: 2.10, 9.12), poor knowledge of glaucoma, 4.46 times (AOR: 4.46, CI: 2.62, 7.58) and absence of regular eye checkup, 2.35 times (AOR: 2.35, 95% CI: 1.09, 5.47) higher odds of being late presenter.

Conclusion

Increasing age, high IOP, poor knowledge of glaucoma, residing far away from the hospital and absence of regular eye checkups were significantly associated with late presentation.

Socio-demographic factors modify awareness, knowledge, and perceived risk of glaucoma in rural and urban residents in Ghana: a population-based survey

Purpose:

To evaluate the awareness, knowledge and the perception of risks of glaucoma among rural and urban dwellers in Ghana, a high prevalent country, in order to provide information for health promotion planning.

Method:

In a population-based descriptive cross-sectional survey, 1200 adults were selected from household settings, using a two-stage cluster and simple systematic random sampling. Quantitative data collection, using interviewer-administered questionnaire, was employed. Descriptive statistics were performed using chi-square, ordinal univariate, multinomial and multivariate logistic regression models used to calculate odds ratio with 95% confidence interval (CI) to identify predictive factors.

Results:

Overall, only 326 (27.2%, 95% CI = 24.6–29.7) indicated they were aware of glaucoma, whereas 331 (27.6%, 95% CI = 24.6–29.7) had ever undergone an eye screening. Low knowledge was demonstrated in 152 (46.6%, 95% CI = 41.2–52.0) and high knowledge in 99 (30.4%, 95% CI = 25.4–35.4) glaucoma-aware participants. Only 238 (19.8%, 95% CI = 17.6–22.1) of respondents presumed themselves to be at risk of developing glaucoma. Having eye examination (within the last 6 months) was positively associated with knowledge (adjusted odds ratio (AOR) = 1.413; 95% CI = 0.9–1.896) and awareness (AOR = 1.13; 95% CI = 0.938–2.449). Three levels of education (no education (AOR = 0.041; 95% CI = 0.016–0.11), primary (AOR = 0.057; 95% CI = 0.018–0.179), and middle school (AOR = 0.254; 95% CI = 0.127–0.51)) were associated with low knowledge while all levels of education were inversely associated with awareness. Perceived risk of glaucoma was also influenced by area of residence (rural (AOR = 0.344; 95% CI = 0.21–0.57)), being young (18–24 years (AOR = 4.308; 95% CI = 2.36–7.88)) and having previously undergone screening for glaucoma (AOR = 13.200; 95% CI = 5.318–32.764).

Conclusion:

The main modifiers of glaucoma awareness and knowledge were education and previous eye examination, but awareness had additional factor of area of residence. Perceived risk of glaucoma was influenced by being young and living in urban areas.

Prevalence of ocular abnormalities in relation to sickle cell disease severity among children in South-western, Nigeria

INTRODUCTION

Sickle cell disease (SCD) ranks high among genetic disorders worldwide. It is characterised by repeated vaso-occlusion with resultant end-organ damage. This process can occur in all vascular beds in the body, including ocular blood vessels and may cause irreversible blindness in advanced stages. Little is known of the relationship between the prevalence of ocular abnormalities among children with SCD and their disease severity.

METHODS

A descriptive cross-sectional study was carried out at the Paediatric Haematology Clinics and the Eye Centre of the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife. Children with SCD in steady state were recruited from the Haematology Clinics and examined for ocular abnormalities at the Eye Centre of the hospital. The subjects SCD severity grade was determined using a previously validated scoring system.

RESULTS

One hundred and twenty (120) children aged 5 to 15 years were examined. Of these, 72 had one or more ocular abnormalities giving the prevalence of ocular abnormalities among them to be 60.0%. Though a higher proportion of children with moderate disease, 23 (65.7%) of 35, compared to those with mild disease, 49 (57.6%) of 85 had ocular abnormalities, this difference was not statistically significant, p = 0.412.

CONCLUSION

Ocular abnormalities among Nigerian children with SCD are common even in steady-state, but not significantly associated with disease severity. Periodic screening for ocular abnormalities should thus be done on them irrespective of disease severity.

Glaucoma awareness, knowledge, perception of risk and eye screening behaviour among residents of Abokobi, Ghana

BACKGROUND

Although glaucoma is the lead cause of irreversible blindness globally, the condition shows no signs or symptoms until later stages. Knowledge about the disease is known to influence utilization of eye screening services. This study aimed at understanding knowledge and perception of risk for glaucoma, as well as eye screening behaviour among residents of Abokobi, a peri-urban community.

METHODS

This was a cross-sectional study that employed quantitative data collection methods, with the use of a questionnaire. Descriptive statistics were used to describe the socio-demographic characteristics, knowledge about glaucoma and eye screening behaviour. Also, associations between socio-demographic factors and awareness as well as perception of risk were analysed using Chi-square test or Univariate Fisher's exact test.

RESULTS

Out of a total of 300 respondents, 60.3 % were females and 39.3 % were aware of glaucoma. Majority (99.1 %) of respondents aware of glaucoma also agreed the disease can result in blindness with only (28 %) affirming that blindness from glaucoma is irreversible. Nearly half (49.7 %) of the respondents perceived themselves to be at risk of developing glaucoma. The results showed that age and education (p <0.0001) were statistically significant with glaucoma awareness. Approximately, 20.7 % of the respondents have had their eye screened with just a few (4.3 %) screening for glaucoma.

CONCLUSION

Although glaucoma awareness was high, the findings display inadequate knowledge about glaucoma. There is a need to effectively inform and educate people about the disease.

Ethnicity and Deprivation are Associated With Blindness Among Adults With Primary Glaucoma in Nigeria: Results From the Nigeria National Blindness and Visual Impairment Survey

PURPOSE

We explored the risk factors for glaucoma blindness among adults aged 40 years and above with primary glaucoma in Nigeria.

PARTICIPANTS AND METHODS

A total of 13,591 participants aged 40 years and above were examined in the Nigeria Blindness Survey; 682 (5.02%; 95 CI, 4.60%-5.47%) had glaucoma by ISGEO's criteria. This was a case-control study (n=890 eyes of 629 persons): glaucoma blind persons were cases and glaucoma not-blind were controls. Education and occupation were used to determine socioeconomic status scores, which were divided into 3 tertiles (affluent, medium, deprived). We assessed sociodemographic, biophysical, and ocular factors by logistic regression analysis for association with glaucoma blindness. Multinomial regression analysis was also performed with nonglaucoma as the reference category.

RESULTS

A total of 119/629 (18.9%; 95% CI, 15.9%-22.4%) persons were blind in both eyes; 510 were controls. There was interethnic variation in odds of blindness; age, male sex, socioeconomic status, prior diagnosis of glaucoma, hypertension, intraocular pressure, and lens opacity were associated with glaucoma blindness. Axial length, mean ocular perfusion pressure, and angle-closure glaucoma were associated with blind glaucoma eyes. In multivariate analysis, Igbo ethnicity (OR=2.79; 95% CI, 1.03-7.57) had higher risk as was being male (OR=4.59; 95% CI, 1.73-12.16) and unmarried (OR=2.50; 95% CI, 1.03-6.07). Deprivation (OR=3.57; 95% CI, 1.46-8.72), prior glaucoma diagnosis (OR=5.89; 95% CI, 1.79-19.40), and intraocular pressure (OR=1.07; 95% CI, 1.04-1.09) were also independent risk factors for glaucoma blindness.

CONCLUSION

Approximately 1 in 5 people with primary glaucoma were blind. Male sex, ethnicity and deprivation were strongly associated with blindness. Services for glaucoma need to improve in Nigeria, focusing on poor communities and men.

Risk factors for late presentation of chronic glaucoma in an Iranian population

Purpose:

To identify risk factors for late presentation in chronic glaucoma.

Materials and Methods:

In a hospital-based case–control study, 312 newly diagnosed consecutive patients with chronic glaucoma were recruited to study in Nikookari Hospital in Tabriz – Iran. Cases were defined as patients presenting with absolute field loss within 5° of fixation or a cup to disc ratio >0.8 in one or both eyes (188 patients). Controls were patients with no absolute field loss within 20° in either eye but otherwise glaucomatous field loss and a cup to disc ratio >0.5 or a difference of 0.2 or greater between the discs (124 patents).

Results:

In logistic regression model, there was a significant association between late presentation and male gender, lower education status, pseudoexfoliative glaucoma, high intraocular pressure (IOP) in the first presentation and no eye exam in last 2 years. Patients with pseudoexfoliative glaucoma had 1.5 times more odd for late presentation (1.52 confidence interval [CI]: 1.14–2.24 P = 0.004). Patients that visited by an ophthalmologist in the last 2 years had 0.5 less likely to present with advanced glaucoma (0.54 CI: 0.32–0.92 P = 0.025). Higher IOP in initial examination was associated with advanced glaucoma. We estimated 1.08 increase in odd (CI: 1.03-1.04 P = 0.001) per increase in 1 mmHg in IOPs above 25 mmHg.

Conclusion:

Our study shows that several risk factors present for late presentation in chronic glaucoma. Our results suggest planning screening programs in high-risk individuals for early detection of glaucoma and prevention of blindness.

Risk factors for open-angle glaucoma in Nigeria: results from the Nigeria National Blindness and Visual Impairment Survey

BACKGROUND

The glaucoma-specific blindness prevalence in Nigeria (0.7 %, 95 % CI 0.6-0.9 %) among those aged ≥40 years is one of the highest ever reported. This study determined the risk factors for open-angle glaucoma (OAG) in adults examined in the Nigeria National Blindness and Visual Impairment Survey.

METHODS

A nationally representative sample of 13,591 people aged ≥40 years in 305 clusters in Nigeria were examined (response rate 90.4 %) between January 2005 to June 2007. Everyone had logMAR visual acuity measurement, Frequency Doubling Technology (FDT) visual field testing, autorefraction, A-scan biometry and optic disc assessment. Full ocular examination (n = 6397), included Goldmann applanation tonometry. Values for defining glaucoma using International Society of Geographical and Epidemiological Ophthalmology criteria were derived from the study population. Disc images were graded by Moorfields Eye Hospital Reading Centre. Socio-demographic factors (age, gender, ethnicity, literacy and place of residence), ocular parameters (intraocular pressure [IOP], axial length and mean ocular perfusion pressure [MOPP]) and systemic parameters (blood pressure, blood glucose and body mass index [BMI]) were assessed for association with OAG.

RESULTS

Thirteen thousand eighty-one (96 %) of 13,591 participants had vertical cup:disc ratio measured in at least one eye. 682 eyes of 462 participants were classified as OAG, with 12,738 controls. In univariate analyses the following were associated with OAG: increasing age, male gender, Igbo and Yoruba ethnic groups, illiteracy, longer axial length, higher IOP, lower MOPP, greater severity of hypertension and low BMI (underweight). In multivariate analysis, increasing age (odds ratio [OR] 1.04, 95 % CI 1.03-1.05), higher IOP (OR 1.22, 95 % CI 1.18-1.25) and Igbo ethnicity (OR 1.73, 95 % CI 1.18-2.56) were independent risk factors for OAG.

CONCLUSION

Case detection strategies for OAG should be improved for those aged ≥40 years and for ethnic groups most at risk as a public health intervention.

The effect of medical therapy on IOP control in Ghana

BACKGROUND

To investigate IOP control following twelve months of continuous medical therapy in Ghana.

METHODS

This retrospective case series included 163 glaucoma patients diagnosed at a referral eye center between 1996 and 2006. Information collected included age, gender, IOP at presentation, six months and one year post treatment and types of anti-glaucoma medications prescribed. Optimal IOP control was defined according to results from the Advanced Glaucoma Intervention Study (AGIS), which demonstrated arrest of visual field progression in patients with IOP < 18 mmHg at all visitations: Level 1 (post-treatment IOP ≤ 21 mmHg); Level 2 (≤ 18 mmHg) and level 3 (≤ 16 mmHg). The principal outcome measure was the achievement of IOP <18 mmHg at six months and twelve month visitations.

RESULTS

One hundred sixty three patients were analyzed. These included 68 males (41.7%) and 95 females (58.3%). The mean age was 57±16 (median 59 years; range 7 - 95 years). There was no significant difference in age (p=0.35) or mean IOP (p=0.08) between genders. The mean pre-treated IOP of 31.9±8.9 mmHg significantly decreased to 21.3±6.6 mmHg at 6 months (p=0.001), with 57.4% of eyes at Level 1 IOP control, 25.3% at Level 2 and 15.4% at Level 3 and decreased further at 12 months to 20.7±6.9 mmHg (p=0.48) with 69.7% of eyes at Level 1, 34.4% at Level 2, and 12.4% at Level 3.

CONCLUSIONS

Current medical regimen is insufficient to reduce IOP to target levels as defined in the Advanced Glaucoma Intervention Study.

Demographic, socio-economic and clinical characteristics: implications for time to presentation at a Nigerian tertiary ophthalmic outpatient population

OBJECTIVE

To investigate the associations between time to presentation, and sociodemographic and clinical characteristics of new adult ophthalmic outpatients at the University of Nigeria Teaching Hospital (UNTH), Enugu, between March and August 2010.

STUDY DESIGN

Hospital-based case-control study.

METHODS

Consecutive new ophthalmic outpatients at UNTH were categorized into controls (early presenters, i.e. <3 months after onset of current eye disease) and cases (late presenters, i.e. >3 months after onset of current eye disease). Relevant data were obtained from the participants' case notes and interviews. Descriptive statistics yielded frequency distributions; bivariate and multivariate comparisons were used to test the significance of associations. P < 0.05 was considered to indicate significance.

RESULTS

Eight hundred and twenty-four subjects [454 males and 370 females, mean age 39.2 (standard deviation 1.2) years, range 19-82 years] participated in this study. There were 370 early presenters and 454 late presenters. Multivariate analysis found that late presentation was significantly associated with age >50 years [odds ratio (OR) 1.34, 95% confidence interval (CI) 1.28-2.22; P < 0.01], female gender (OR 1.63, 95% CI 1.52-2.11; P < 0.01), residence >20 km from UNTH (OR 0.65, 95% CI 0.38-0.89; P = 0.0212), individual-level deprivation (OR 0.69, 95% CI 0.55-0.92; P = 0.0324) and subnormal visual acuity at presentation (OR 1.32, 95% CI 1.05-1.76; P = 0.0353).

CONCLUSIONS

At UNTH, most new adult ophthalmic outpatients present >3 months after onset of their current eye disease. Measures to overcome age-, gender- and distance-related causes of late presentation, grassroots economic empowerment of the feeder population and public education about eye health are required.

Epidemiology of glaucoma in sub-saharan Africa: prevalence, incidence and risk factors

PURPOSE

The purpose of this study is to review the epidemiology of different types of glaucoma relevant to Sub-Saharan Africa (SSA) and to discuss the evidence regarding the risk factors for onset and progression of glaucoma, including risk factors for glaucoma blindness.

METHODS

Electronic databases (PubMed, MedLine, African Journals Online- AJOL) were searched using the full text, Medical Subject Headings (MeSH) terms, author(s) and title to identify publications since 1982 in the following areas: population-based glaucoma prevalence and incidence studies in SSA and in African-derived black populations outside Africa; population-based prevalence and incidence of blindness and visual impairment studies in SSA including rapid assessment methods, which elucidate the glaucoma-specific blindness prevalence; studies of risk factors for glaucoma; and publications that discussed public health approaches for the control of glaucoma in Africa.

RESULTS

Studies highlighted that glaucoma in SSA is a public health problem and predominantly open-angle glaucoma. It is the second-leading cause of blindness, has a high prevalence, an early onset and progresses more rapidly than in Caucasians. These factors are further compounded by poor awareness and low knowledge about glaucoma even by persons affected by the condition.

CONCLUSION

Glaucoma care needs to be given high priority in Vision 2020 programs in Africa. Many questions remain unanswered and there is a need for further research in glaucoma in SSA in all aspects especially epidemiology and clinical care and outcomes involving randomized controlled trials. Genetic and genome-wide association studies may aid identification of high-risk groups. Social sciences and qualitative studies, health economics and health systems research will also enhance public health approaches for the prevention of blindness due to glaucoma.

Comparison of moderate and advanced glaucoma patients in Ghana

Purpose

To compare moderate and advanced glaucoma patients in Ghana.

Methods

A retrospective cross-sectional study of 164 patients with primary open-angle glaucoma (POAG) were separated into moderate and advanced glaucoma groups. Definitions of moderate and advanced POAG were derived from International Geographical and Epidemiologic Ophthalmology criteria and included clinical assessment of optic disc atrophy and Humphrey automated perimetry. Data were collected at the patient’s first visit prior to initiation of therapy. Eligible POAG patients included those ≥30 years old with reliable Humphrey visual field (HVF) results, no past POAG diagnosis, treatment, or evidence of a secondary cause for glaucoma. Main outcome measures included comparisons of intraocular pressure (IOP), cup-to-disk ratio (CDR), best corrected visual acuity (VA), age, Humphrey mean deviation (MD), and pattern standard deviation (PSD).

Results

Of 164 charts reviewed, 90 (54.9%) advanced and 74 (45.1%) moderate POAG patients were compared. Mean age was 59.36 versus 55.53 years, respectively. Significant differences in IOP, CDR, CDR asymmetry, and HVF results were described. IOP > 30 mmHg was associated with CDR > 0.7 and MD greater than −12 dB in both eyes.

Conclusion

Significant differences were found between IOP, CDR, MD and PSD values. HVF is predictive of pretreated IOP, CDR, and severity of POAG and it is strongly encouraged as part of the standard glaucoma work up in all Ghanaian patients.

HRT III glaucoma probability score and Moorfields regression across the glaucoma spectrum

OBJECTIVE

To compare the agreement, sensitivity, and specificity of the Heidelberg Retina Tomograph III Glaucoma Probability Score (GPS) and Moorfields Regression Analysis (MRA) across the spectrum of glaucomatous visual field (VF) loss.

DESIGN

Retrospective observational study.

METHODS

Data from 247 glaucoma patients and 142 controls who underwent standard achromatic perimetry (SITA-SAP) and Heidelberg Retina Tomograph III imaging within 6 months were analyzed. Sensitivity, specificity, agreement, and discrimination capability of MRA and GPS were assessed.

RESULTS

Age-adjusted specificity was 92% and 93% and sensitivity was 76.88 and 80.85 for GPS and MRA, respectively. Sensitivity for early VF loss [mean deviation (MD) < -5 dB] (N=81) was 66.64% and 69.82%, for moderate VF loss (-5 dB <MD < -15 dB) (N=104) was 78.91% and 85.13%, and for advanced VF loss (MD> -15 dB) (N=62) was 87.70% and 86.48% (GPS and MRA, respectively). Age-specific receiver operating characteristics ranged from 0.89 to 0.92 and from 0.87 to 0.90 (GPS and MRA, respectively). Kappa ranged from 0.64 to 0.77.

CONCLUSIONS

Specificity for MRA and GPS was similar and agreement was good. GPS offered slightly higher age-specific receiver operating characteristic. GPS, which does not require contour line placement, may have a potential role in screening for severe glaucomatous damage.