Clinical and pathological features of chronic glaucoma in north-east Ghana

Severity of Visual Field Loss at First Presentation to Glaucoma Clinics in England and Tanzania

Purpose: To compare severity of visual field (VF) loss at first presentation in glaucoma clinics in England and Tanzania.Methods: Large archives of VF records from automated perimetry were used to retrospectively examine vision loss at first presentation in glaucoma clinics in Tanzania (N = 1,502) and England (N = 9,264). Mean deviation (MD) of the worse eye at the first hospital visit was used as an estimate of detectable VF loss severity.Results: In Tanzania, 44.7% {CI_95%: 42.2, 47.2} of patients presented with severe VF loss (< -20 dB), versus 4.6% {4.1, 5.0} in England. If we consider late presentation to also include cases of advanced loss (-12.01 dB to -20 dB), then the proportion of patients presenting late was 58.1% {55.6, 60.6} and 14.0% {13.3, 14.7}, respectively. The proportion of late presentations was greater in Tanzania at all ages, but the difference was particularly pronounced among working-age adults, with 50.3% {46.9, 53.7} of 18-65-year-olds presenting with advanced or severe VF loss, versus 10.2% {9.3, 11.3} in England. In both countries, men were more likely to present late than women.Conclusions: Late presentation of glaucoma is a problem in England, and an even greater challenge in Tanzania. Possible solutions are discussed, including increased community eye-care, and a more proactive approach to case finding through the use of disruptive new technologies, such as low-cost, portable diagnostic aids.

Safety and effectiveness of primary transscleral diode laser cyclophotoablation for glaucoma in Nigeria

Importance

To investigate the safety, effectiveness and follow‐up rates after transscleral diode laser cyclophotocoagulation as primary treatment for seeing eyes with primary open angle glaucoma in Bauchi, Nigeria.

Background

There is a high prevalence of primary open angle glaucoma in Africa where adherence to medical treatment and acceptance of surgery are poor.

Design

Prospective case series.

Participants

New glaucoma patients where surgical intervention was recommended.

Methods

A diode 810 nm laser G‐probe was used under retrobulbar anaesthesia to deliver approximately 20 shots for 2000 ms, titrating the power. If both eyes were treated the first was the study eye. Repeat treatment offered if the intraocular pressure (IOP) was >21 mmHg on two consecutive visits.

Main Outcome Measures

IOP < 22 mmHg, change in ≥2 lines of Snellen visual acuity (VA), and complications.

Results

201 out of 204 eyes with complete data analysed. Mean age 52 years, 17 (8.3%) eyes were re‐treated. Mean pre‐treatment IOP was 39 (SD 11) mmHg. 106 (53%) attended at 12 months when the mean IOP was 19 (7–45) mmHg; 77 (73%) had IOP < 22 mmHg. VAs were better in 13 (12.3%) and worse in 23 (21.7%) eyes. Postoperative complications included mild uveitis (5.5%), corneal oedema (2.5%), severe uveitis (0.5%) and transient hypotony (2.0%). No hypotony at 12 months.

Conclusions and Relevance

Transscleral diode laser cyclophotocoagulation controlled IOP in almost three quarters of eyes at 12 months with short‐term preservation of vision and minimal complications. Poor follow‐up in this setting highlights the need for an effective, safe and acceptable treatment where regular follow‐up is less critical.

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.

Primary open angle glaucoma in northern Nigeria: stage at presentation and acceptance of treatment

Background

To determine the stage of primary open angle glaucoma at presentation at a tertiary eye unit, to assess patient’s knowledge of glaucoma and acceptance and subsequent adherence to treatment.

Method

Information collected prospectively on new glaucoma patients aged 30 or more years included distance from residence and what they knew about glaucoma and its treatment. Treatment offered took account of disease severity and socioeconomic factors. Reasons for not accepting surgery were recorded. At follow up intraocular pressure (IOP) was measured and adherence to medication assessed verbally. Four categories of severity were defined based on visual acuity and visual fields defects in the worse eye.

Results

131 patients were recruited (mean age 52.8 years; 62 % male). Most attended because of symptoms (70 %). Mean IOP in affected eyes was 31.9+/-SD 12.4 and mean vertical cup:disc ratio was 0.8. 99 eyes (47 %) had a visual acuity of light perception or worse. Risk factors for advanced/end-stage disease were age >50 years, living >10 km from the hospital, some awareness of glaucoma, not being literate, being unemployed and presenting with symptoms. In multivariable analysis older age and poor knowledge of glaucoma remained independent risk factors. 75 were offered trabeculectomy: five agreed but only one underwent surgery. Reasons for rejecting surgery were fear (37 %), preferred medical treatment (27 %) and cost (15 %). 32/85 (24 %) participants started on topical medication attended follow up. 72 % reported excellent compliance but only 56 % of glaucomatous eyes had IOPs less than 21mmHg.

Conclusions

To prevent glaucoma blindness strategies are required which promote earlier detection, with counselling to promote acceptance of and adherence to treatment.

Epidemiological properties of primary open angle glaucoma in Nigeria

Background. Primary open angle glaucoma (POAG) is progressive chronic optic neuropathy in adults in which intraocular pressure (IOP) and other currently unknown factors contribute to damage. POAG is the second commonest cause of avoidable blindness in Nigeria. Pattern of Presentation. POAG is characterized by late presentation. Absence of pain which is a driving force for seeking medical help, inadequacy of trained eye care personnel, paucity of facilities, misdistribution of resources, lack of awareness, poor education, and poverty may all contribute to this. Medical and surgical treatment options available are challenging and tasking. Screening for Glaucoma. Screening is the presumptive identification of unrecognized disease (POAG) by applying test(s) which can be applied rapidly. Such test(s) should be of high reliability, validity, yield, acceptable, and cost effective. The test should ideally be sensitive, specific, and efficient. It is difficult to select a suitable test that meets these criteria. Intraocular pressure (IOP) appears to be the easiest option. But, high IOP is not diagnostic nor does normal value exclude the disease. Health education is a possible strategy in early case detection and management. Treatment of POAG. Glaucoma treatment can either be medical or surgical (this includes laser). Considering unavailability, potency, cost, and long-term effects of medication, surgery (trabeculectomy) could be a better option. Laser trabeculoplasty is available in a few centers. Viscocanalostomy is not routinely performed. Patient education is vital to success as management is for life. Conclusion. POAG remains a cause of avoidable blindness in Nigeria. There is need for long-term strategy to identify patients early and institute prompt management. Improvement in training of eye care personnel and provision of up to date equipment is essential in achieving this goal.

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.

Presentation patterns of primary open angle glaucomas in north eastern ghana

INTRODUCTION

Previous reports have indicated that open angle glaucoma is a major problem in the Upper East region of Ghana. Such reports have shown high prevalence among young patients under the age of 40 years. None has given enough details on the burden, pattern of distribution and extent of changes in the optic nerve head and intraocular pressures. This study aims at addressing these issues in order to highlight the situation.

METHODS

Retrospective case series involving review of clinical records of all first-time attendants diagnosed with glaucoma at the Bawku Hospital between October 2003 and December 2005. Case definitions and diagnostic criteria were made to conform as much as possible to the ISGEO and EGS recommendations. Data analysis was done using the Epi-Info software.

RESULTS

Records of 891 eyes of 446 patients were reviewed. Median age was 56 years with 23.6% below 40 years. POAG was diagnosed in 98.4% with 8.3% manifesting the NTG variant. One third (34.1%) of all the patients reported bilaterally blind while half were uniocularly blind. Nearly a third (70.2%) had CDRs>0.8 while more than half (54.9%) had CDRs measured at unity. Males were twice as many as females (65.5% and 34.5% respectively) but blindness sequelae among the latter was twice as much and this was statistically significant (p=0.0008;chi2 test)

CONCLUSION

late presentation of open angle glaucoma cases is a major problem in this part of Ghana. We recommend a more aggressive approach to tackle the disease and reduce its blindness sequelae.

Outcome of trabeculectomies without adjunctive antimetabolites

SUMMARY BACKGROUND

The effectiveness of trabeculectomy in the management of glaucoma is well known. It is the most common intervention for most glaucoma cases treated in the Upper East region. In this region trabeculectomies are, however, performed without adjunctive antimetabolites.

OBJECTIVE

To report on the outcome of trabeculectomy without adjunctive antimetabolites in controlling the intraocular pressures of eyes with Primary Open Angle and Normal Tension Glaucomas.

DESIGN

Retrospective, non-comparative interventional case study

METHOD

Records of 191 eyes of 164 patients who had undergone standard trabeculectomy were retrospectively analyzed.

OUTCOME MEASURE

Successful intraocular pressure control defined as IOP less than 22 mmHg or a reduction of 30% if pre-operative pressure was already less than 22mmHg.

RESULTS

There were 185 (96.8%) eyes with Primary Open Angle glaucoma and 6 (3.2%) with the Normal Tension variant. Mean age of patients was 50.6 years (Range 17-85) with 22% aged below 40 years. There was a statistically significant difference between the mean pre-op and post-op intraocular pressures (38.09, SD=6.11 versus 18.97, SD=7.28 mmHg respectively); p=0.0001. The procedure was effective in controlling the intraocular pressures to below 22mmHg in 88.46% and below 18mmHg in 67.95% of OAG eyes at six months. In eyes with NTG only one out of six (16.7%) achieved a successful 30% target pressure reduction.

CONCLUSION

Trabeculectomy alone was effective in controlling IOPs to less than 22 mmHg in POAG. Lower IOP levels needed to control progressive visual field loss may require the use anti-metabolites.

Onchocerciasis: a potential risk factor for glaucoma

BACKGROUND

Onchocerciasis is a microfilarial disease that causes ocular disease and blindness. Previous evidence of an association between onchocerciasis and glaucoma has been mixed. This study aims to further investigate the association between onchocerciasis and glaucoma.

METHODS

All subjects were patients at the Bishop John Ackon Christian Eye Centre in Ghana, west Africa, undergoing either trabeculectomy for advanced glaucoma or extracapsular extraction for cataracts, who also had a skin snip biopsy for onchocerciasis. A cross sectional case-control study was performed to assess the difference in onchocerciasis prevalence between the two study groups.

RESULTS

The prevalence of onchocerciasis was 10.6% in those with glaucoma compared with 2.6% in those with cataracts (OR, 4.45 (95% CI 1.48 to 13.43)). The mean age in the glaucoma group was significantly younger than in the cataract group (59 and 65, respectively). The groups were not significantly different with respect to sex or region of residence. In models adjusted for age, region, and sex, subjects with glaucoma had over three times the odds of testing positive for onchocerciasis (OR, 3.50 (95% CI 1.10 to 11.18)).

CONCLUSIONS

This study has shown a positive association between subclinical onchocerciasis and glaucoma. This finding emphasises the importance of eradication of onchocerciasis from west Africa.

Evaluation of risk factors for advanced glaucoma in Ghanaian patients

PURPOSE

This study was to determine factors associated with individuals presenting late with advanced glaucomatous optic nerve damage.

METHODS

A case-control study recruiting 123 patients with early features of primary open angle glaucoma (control) and 93 patients with advanced glaucoma (cases) was carried out for risk-factor analysis. Exposures of interest included those already established as major risk factors for glaucoma. These were initial intraocular pressure (IOP), age, and family history. In addition, occupation, ethnic origin, history of diagnosis of diabetes mellitus, hypertension, sickle cell disease, and previous eye examination were of interest.

RESULTS

Univariate analysis showed that initial IOP>31 mmHg, age of > 60 years, absence of family history of glaucoma, occupational grouping, ethnicity, and male sex were associated with advanced glaucoma at presentation. Adjusted odds ratio or by multiple logistic regression model showed that initial IOP>31 mmHg in a patient was more likely to present with advanced glaucoma (OR 2.66, 95% confidence interval (CI) 1.45, 4.91; P-value 0.0017) than lower pressures. Patients aged 60-69 years (OR 2.53, 95% CI 1.01, 6.31; P-value 0.0473) and 70-90 years (OR 5.16, 95% CI 1.97, 13.51; P-value 0.0008) were more likely to present with advanced glaucoma than younger ones

CONCLUSIONS

Subjects with initial IOP>31 mmHg were nearly three times more likely to present with advanced glaucoma than those with IOP<32 mmHg. Subjects over the age of 60 years were more than two times likely to present with advanced glaucoma than younger subjects.

Prevalence of glaucoma in an African population

PURPOSE

To determine the prevalence of primary open-angle glaucoma (POAG) in a Ghanaian population aged 30 years and above and to describe any ethnic variations in glaucoma prevalence in this population.

METHOD

A cross-sectional prevalence survey for POAG was carried out on residents of 30 years and above in the Akwapim-South district of Ghana. The principal investigator examined all glaucoma suspects and those diagnosed as glaucoma in the initial screening to determine all definite cases of POAG. All cases had intraocular pressure measurements. Glaucoma cases and suspects and some normal subjects had fundus biomicroscopy with 78 D Volk lens, and Humphrey FDT N-30 visual fields plotted.

RESULTS

A total of 1843 people aged 30 years were screened from the population. The standardized age-specific prevalence was 7.7% (30 years and above) and 8.5% (40 years and above). The best-fit trend line for prevalence/age relationship was exponential. No gender or ethnic difference in prevalence was found.

CONCLUSIONS

The prevalence of POAG in this population is high and comparable to those in black populations in Barbados and St. Lucia

Visual loss in urban and rural chronic glaucoma patients in Ghana

The visual acuity of newly diagnosed glaucoma patients in a rural and an urban area were compared in a hospital-based cross-sectional study in Ghana. Age at presentation was strikingly higher in the rural group due to local factors which result in a difference-in-age structure of the rural and urban population. The crude relative frequency of bilateral blindness was significantly higher for rural than urban. However, with age adjusted relative frequencies for bilateral blindness there was no significant difference between rural and urban patients. There was significant difference between them for those aged 51-71 when blindness in one or both eyes were considered together. There was more consistent blindness in the rural community: the difference was attributed to local factors such as better access to eye care in the urban group.

Intraocular pressure and gonioscopic findings in rural communities mesoendemic and nonendemic for onchoceriasis, Kaduna State, Nigeria

PURPOSE

To report on glaucoma-related ocular parameters, namely intraocular pressure and peripheral anterior synechiae, in the presence of onchocercal infection.

METHODS

Two computer-generated random samples of individuals were drawn from communities mesoendemic and nonendemic for onchocerciasis respectively. Applanation tonometry and gonioscopy were carried out on these individuals.

RESULTS

Four hundred and thirty-six and 319 individuals from the mesoendemic and nonendemic communities were examined respectively. The mean intraocular pressure was 1.58 mmHg lower in the individuals from the mesoendemic communities compared with those from the nonendemic communities (p < 0.001) despite the prevalence of peripheral anterior synechiae being higher in the mesoendemic communities. In these communities, there was strong evidence that the prevalence of peripheral anterior synechiae increased with increasing microfilarial load.

CONCLUSIONS

Onchocercal infection produces a low-grade inflammatory process, which may result in a lowering of intraocular pressure despite the formation of peripheral anterior synechiae. Glaucomatous optic nerve damage may therefore not be the primary cause of visual loss in ocular onchocerciasis as this occurs late and is probably preceded by other blinding onchocercal pathology.

A randomised trial of the effect of intraoperative 5-FU on the outcome of trabeculectomy in east Africa

AIMS

To determine if intraoperative application of 5-fluorouracil (5-FU) improves the prognosis for trabeculectomy in east Africa.

METHODS

68 eyes with chronic open angle glaucoma were included in a randomised trial of intraoperative 5-FU versus placebo. Main outcome measures were intraocular pressures at 6 months and probability of failure at 2 years.

RESULTS

180 days after surgery the mean intraocular pressure (IOP) was 17.4 (SD 6.1) mm Hg in the placebo group and 16.9 (5.8) mm Hg in the 5-FU group. By 2 years after trabeculectomy, the probability of successful IOP control was 70.6% in the placebo group, and 88.8% in the 5-FU group. The placebo group was 2.18 times (95% CI 0.67 to 7.15) more likely to require additional IOP lowering procedures than the 5-FU group. Among patients followed for 2 years, 30% lost 0.3 logMAR units of visual acuity.

CONCLUSIONS

Trabeculectomy in Africa has an acceptable success rate which may be enhanced by the use of intraoperative 5-FU. It is estimated that this would cost approximately 1.25 pounds sterling per trabeculectomy failure prevented.

Ophthalmology in Luanda (Angola): a hospital based report

AIMS/BACKGROUND

As part of a 4 year Spanish development aid programme, an ophthalmic hospital was set up in Luanda in 1991 for the in situ training of local ophthalmologists. Presented here are the data obtained from 4201 patients treated during the first 2 years of the project.

METHODS

Patients were referred to the institute from the emergency ward at the Luanda General Hospital, selected mainly according to the severity of their disease. The following data were collected from the clinical reports: age, sex, diagnosis (single or multiple), type of treatment (medical or surgical), acuity of the best eye at the time of diagnosis, and main disease group.

RESULTS

The main causes of blindness treated were: cataracts; glaucoma; optic nerve diseases (neuritis and atrophy); trauma; xerophthalmia; uveitis; hereditary retinal diseases (degenerative myopia, retinitis pigmentosa, albinism, and Stargardt's disease); retinal detachment; and diabetic retinopathy.

CONCLUSIONS

Sanitary resources in Angola are generally inadequate, and ophthalmic care is no exception to this. Owing to the high percentage of preventable or treatable blinding diseases in this environment, a campaign of social education should always be held along with any medical programme, in order to optimise the available resources.

Glaucoma screening

National screening programmes probably cannot be justified at present given difficulties with test validity, manpower, and some doubts about the natural history of the disease. The opportunity cost could be prohibitive, especially when resources are badly needed in other areas of ophthalmology, such as cataract programmes, diabetic retinopathy, and low vision services. The situation could change with an improved test with greater validity for primary screening and such tests are currently under investigation. The results of these investigations will not be available for at least three years. Screening for eye disease at the primary care level begs questions about manpower which need to be answered not just for glaucoma screening but also for detection of diabetic retinopathy and visual impairment in the elderly. A new cadre of ophthalmic paramedics as is already in wide use in some developing countries, who amalgamate the skills of optometrist, orthoptist, and eye trained nurse, is an interesting possibility. Meanwhile, much has to be done to improve current case finding with agreed standards of examination and referral criteria and special facilities available for those at increased risk.

A prospective trial of intraoperative fluorouracil during trabeculectomy in a black population

In a study population of black Africans with advanced glaucoma in Ghana we conducted a prospective study of intraoperative 5-fluorouracil alone. Eyes undergoing trabeculectomy were randomly selected either to receive or not receive a single intraoperative application of 5-fluorouracil (50 mg/ml for five minutes). Fifty-five eyes had a mean follow-up of 282 days (minimum, 92 days). Twenty of 24 eyes (83%) in the 5-fluorouracil group vs 12 of 31 eyes (39%) in the control group had postoperative intraocular pressure of 20 mm Hg or less with or without medical therapy (P = .01). Eleven of 24 eyes (46%) in the 5-fluorouracil group and five of 31 eyes (16%) in the control group had intraocular pressure of 15 mm Hg or less (P = .02). Without medical therapy, 17 of 24 eyes (71%) in the 5-fluorouracil group and ten of 31 eyes (32%) in the control group had intraocular pressure of 20 mm Hg or less (P = .02). The overall complications were similar in the two groups. In this population, intraoperative 5-fluorouracil markedly improved the ability of trabeculectomy to lower intraocular pressure. We recommend that intraoperative 5-fluorouracil be considered in glaucoma surgery with poor prognosis as an alternative to postoperative subconjunctival injections when multiple injections are not feasible.

Chronic glaucoma in northern Ghana--a retrospective study of 397 patients

A retrospective study of 397 patients with chronic glaucoma in North-East Ghana seen in 1986/87 showed 71% of the patients to be male and 26% to be aged under 40 years. Fifty two per cent of eyes were already blind (V/A less than 3/60) at presentation. Blindness was associated with younger age at presentation, and greater distance of residence from the hospital. Only 19% of patients undergoing treatment were attending for follow-up at six months. Of those patients treated medically who returned for follow-up at six months only 17% had an intraocular pressure less than 22 mmHg. While of the patients treated surgically 84% of those seen at six months had an IOP below 22 mmHg.