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

Epidemiology and clinical presentation of glaucoma in a referral facility in Ghana: Any lessons for public health intervention?

The purpose of this study was to evaluate the epidemiological and clinical profile of patients living with glaucoma and receiving care in a tertiary eye center in Ghana. This was a hospital-based retrospective study of clinical records of glaucoma patients from January 2010 to December 2019. The study involved collating demographic information of patients, clinical presentation, and the management of glaucoma. A total of nineteen thousand (19,000) charts were retrieved from the eye center's archives. Out of these, 660 (3.5%) records of patients qualified for the study and were analyzed. There were 398 (60.3%) males and 262 (39.7%) females. Their ages ranged from 9 to 86 years (mean age = 47.30; SD ± 16.86 years). The averages of ocular parameters of 1,320 eyes (660 patients) were visual acuity = 0.26 ± 0.55 logMAR; intraocular pressure: 17.31 ± 6.11 mmHg; cup-to-disc ratios: 0.67 ± 0.17 D; and the average retinal nerve fibers thickness was 95.03 ± 21.74 μm. The mainstay of treatment was the sole use of medication. Males were the major group receiving glaucoma care at the tertiary level. Glaucoma cases included juveniles but the mean age suggests most were of adult-onset. Socio-demographic characteristics affected the diagnosis and management of glaucoma among patients receiving care at a referral center. Public health, stakeholders, and policymakers' interventions can help identify individuals with glaucoma.

Observational Outcomes of Initial Trabeculectomy With Mitomycin C in Patients of African Descent vs Patients of European Descent: Five-Year Results

Importance

There is evidence that patients of African descent (AD) experience higher surgical failure rate after trabeculectomy without antimetabolites.

Objective

To compare outcomes of initial trabeculectomy with mitomycin C in AD patients with those of patients of European descent (ED) and to identify prognostic factors for failure.

Design, Setting, and Participants

In this retrospective matched cohort study, 135 eyes of 105 AD patients were matched with 135 eyes of 117 ED patients by age (within 5 years), surgeon, lens status, and follow-up time (within 1 year) from a single tertiary academic center.

Interventions

Initial trabeculectomy with mitomycin C.

Main Outcomes and Measures

Criteria A, B, and C defined qualified success rates as final intraocular pressure of 18 mm Hg or less, 15 mm Hg or less, and 12 mm Hg or less, respectively, in addition to 20% or more, 25% or more, and 30% or more reduction of intraocular pressure or reduction of 2 or more medications. Kaplan-Meier survival curves were compared with log-rank test in AD and ED patients, and Cox proportional hazard models were used to estimate the influence of race/ethnicity on surgical success accounting for confounding variables.

Results

Of the 105 AD patients, 56 (53.3%) were female, and the mean (SD) age was 67.5 (10.4) years; of the 117 ED patients, 64 (54.7%) were female, and the mean (SD) age was 68.2 (10.0) years. For AD patients compared with ED patients, the qualified success rates at 5 years for criteria A were 61% and 67%, respectively (difference, 7.3%; 95% CI, 4.4-10.4); for criteria B, 43% and 60% (difference, 17.6%; 95% CI, 15.2-20.0); and for criteria C, 25% and 40% (difference, 15.8%; 95% CI, 11.1-20.5). On multivariable Cox regression analyses, AD was associated with higher failure rate with criteria B and C for qualified success and with all criteria for complete success (ie, no need for medications). Incidence of bleb leaks was higher in the AD group (29 vs 11 eyes; P = .002). Additionally, AD patients required additional glaucoma surgeries more often than ED patients (47 vs 26 eyes; P = .004).

Conclusions and Relevance

African descent was associated with higher failure rates and higher incidence of bleb leaks after initial trabeculectomy with mitomycin C compared with European descent. If this is subsequently shown to be a cause and effect, the findings need to be considered when surgical treatment of glaucoma is contemplated in AD patients.

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.

The Rationale for Selective Laser Trabeculoplasty in Africa

Glaucoma is the leading cause of irreversible blindness in Africa. The condition is treatable but not curable. There are numerous obstacles to glaucoma care in Africa, including availability, accessibility and affordability of treatments, as well as medication nonadherence among patients. Medical therapy is costly relative to the average income in Africa and it requires daily self-dosing by patients. Surgery is of limited availability in many regions in Africa, and a high proportion of patients refuse surgery because it is expensive. Selective laser trabeculoplasty (SLT) proves to be a favorable alternative to medical or surgical care, as it is highly effective and safe in people of African descent, more cost-effective than medical therapy, quick and easy to perform, and portable. The procedure also requires no postoperative care, thus obviates the issue of nonadherence. In uncontrolled studies, SLT has a high response rate and it lowers intraocular pressure by 30% to 40%, which exceeds the goal in international guidelines for initial therapies. The African Glaucoma Consortium (AGC), a member-driven stakeholder collective, has been formed in part to develop the infrastructure for continent-wide improvements in glaucoma care. It embraces SLT as a potential key tool in their development plans. The mission of AGC includes improving clinical care by educating existing and new health care professionals to expand the provider network, by conducting trials to identify optimal care strategies for glaucoma in Africa, and by facilitating the development of an integrated network of Centers of Excellence to bring SLT and other crucial glaucoma therapies to communities throughout Africa.

Can Adapted Motivational Interviewing Improve Uptake of Surgical or Laser Treatment for Glaucoma in Nigeria: Randomized Controlled Trial

PURPOSE

To assess whether adapted motivational interviewing (MI) has any impact on the proportion of participants who subsequently underwent surgery or laser treatment for glaucoma.

MATERIALS AND METHODS

A single site randomized controlled trial in Bauchi, Nigeria. Participants were new patients with a confirmed diagnosis of primary open-angle glaucoma in 1 or both eyes, where surgery or laser was recommended. Intervention was a session of MI adapted for glaucoma and the local context, using an interview guide based on local qualitative research. Participants were randomly allocated to intervention or usual care. Usual care was routine explanation by an ophthalmologist and an educational pamphlet. After the interview, a 12-item Working Alliance Inventory questionnaire was administered to patient-interviewer pairs to assess the collaborative relationship.

RESULTS

Two hundred seventy-six glaucoma patients participated; 70% males. One hundred thirty-five (49%) were assigned to adapted MI and 141 to usual care. All received the intervention as allocated. Uptake (ie, the proportion who underwent treatment) of laser or surgery in the MI group was 52% compared with 45% in the usual care group (risk difference 7.2%; 95% confidence interval, -4.5% to 18.9%). Mean Working Alliance Inventory scores were 68.0 for interviewers and 68.5 for participants with a combined reliability coefficient of 93.9% (ie, high internal consistency and reliability).

CONCLUSIONS

We observed only a small increase in the uptake of surgery or laser with MI compared with usual care which was not statistically significant. Although only 1 in 2 patients accepted surgery or laser in this trial, this is a much higher proportion than in other studies.

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.

Glaucoma, "the silent thief of sight": patients' perspectives and health seeking behaviour in Bauchi, northern Nigeria

BACKGROUND

In Nigeria, glaucoma has a high prevalence and is the second cause of blindness among adults after cataract. People with glaucoma frequently present very late with advanced disease, and acceptance of and adherence to treatment is low. The purpose of the study was to explore how patients' understand and respond to glaucoma in order develop an intervention to improve adherence to treatment.

METHOD

Hospital based qualitative study. Six focus group discussions were held with patients with advanced disease and who had either undergone glaucoma surgery, were receiving medical treatment, or had neither surgery nor medical treatment. Two traditional healers who treat eye conditions were interviewed. Audio files were transcribed, translated into English and recurring themes coded and categorized as the impact of vision loss, and understandings of the disease and its management.

RESULTS

Visual loss impacted significantly on the lives of people with glaucoma in many ways. Many heard the term "glaucoma" for the first time during the study. Local terms to describe the symptoms included Hawan jinin ido ("hypertension of the eye"). Patients sought treatment in pharmacies, or with traditional healers who had different interpretations of glaucoma and its treatment to biomedical understandings. Cost and forgetfulness were the main reasons for low adherence to treatment while fear was a reason for not accepting surgery. Lack of money and negative staff attitudes were reasons for low follow up.

CONCLUSION

Halting the progression of glaucoma is possible with treatment but the condition will remain a "silent thief of sight" in West Africa unless awareness, uptake of services and adherence to treatment improve. Understanding how glaucoma is locally conceptualised, lived with and responded to by patients is essential to aid the design of interventions to prevent glaucoma blindness in Africa. Findings have been used to adapt a motivational interviewing intervention, which is being evaluated in a clinical trial.

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.

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.

Primary Open-Angle Glaucoma in Individuals of African Descent: A Review of Risk Factors

OBJECTIVE

To identify the major risk factors for primary open-angle glaucoma (POAG) in individuals of African descent.

METHODS

We searched PubMed for relevant articles, with results spanning April 1947 to present. All abstracts were reviewed and, where relevant to POAG and race, articles were catalogued and analyzed. Additional sources were identified through citations in articles returned by our search.

RESULTS

Numerous potential POAG risk factors were identified and organized into categories by demographics (age, sex, and skin color), lifestyle choices (smoking, alcohol), comorbidities (hypertension, diabetes, and obesity), ophthalmic findings (eye structure, central corneal thickness, corneal hysteresis, elevated intraocular pressure, myopia, cataract, and vascular abnormalities), family history, socioeconomic status, and adherence. Older age, male sex, lower central corneal thickness, decreased corneal hysteresis, elevated intraocular pressure, myopia, vascular abnormalities, and positive family history were definitively associated with increased risk of POAG.

CONCLUSIONS

Individuals at greatest risk for POAG should be screened by an ophthalmologist to allow earlier detection and to slow disease progression. Further studies on the genetics of the disease will provide more insight into underlying pathologic mechanisms and could lead to improved therapeutic interventions. Continued research in urban areas with large populations of blacks is especially needed.

The clinical characteristics of patients with glaucoma presenting to Botswana healthcare facilities: an observational study

OBJECTIVE

This study aimed to establish the clinical characteristics of patients with glaucoma attending eye care facilities in Botswana, and management of glaucoma among patients who received care in these facilities. The study also aimed to calculate the number of new diagnoses of glaucoma within the glaucoma service.

DESIGN

A prospective, hospital-based, observational study.

SETTING

A multicentre study was undertaken in government-run eye departments in Botswana from June to August 2012.

PARTICIPANTS

All patients with a diagnosis of glaucoma attending clinics at seven study sites were invited to participate.

OUTCOME MEASURES

Examination findings, diagnosis and management were extracted from individual patient-held medical charts. Sociodemographic characteristics, patient knowledge and understanding of glaucoma were assessed through face-to-face interviews. In addition, details of outpatient attendances for 2011 were collected from 21 government-run hospitals.

RESULTS

The majority of the 366 patients interviewed had a diagnosis of primary glaucoma (86.6%). The diagnoses were mainly made by ophthalmologists (48.6%) and ophthalmic nurses (44.0%). Many patients (38.5%) had been symptomatic for over 6 months before visiting an eye clinic. The mean presenting intraocular pressure was 28.2 mm Hg (SD 11.9 mm Hg). Most follow-up patients (79.2%) had not received surgery, however, many (89.5%) would accept surgery. Only 11.5% of participants had heard of glaucoma prior to diagnosis. Many participants (35.9%) did not understand glaucoma after being diagnosed. The majority (94.9%) of living first-degree relatives had never been examined. The number of newly diagnosed glaucoma cases for 2011 in the south of the country was 14.1/100,000; 95% CI (12.0 to 16.5), in the north it was 16.2/100,000; 95% CI (13.8 to 19.0).

CONCLUSIONS

Glaucoma is a significant burden that presents challenges to ophthalmic services in Botswana. Many patients have limited understanding of the condition and poor access to services. There is a need to develop a treatment infrastructure to include safe surgery and a reliable supply of effective medication.

Adapted motivational interviewing to improve the uptake of treatment for glaucoma in Nigeria: study protocol for a randomized controlled trial

BACKGROUND

Glaucoma is a chronic eye disease associated with irreversible visual loss. In Africa, glaucoma patients often present late, with very advanced disease. One-off procedures, such as laser or surgery, are recommended in Africa because of lack of or poor adherence to medical treatment. However, acceptance of surgery is usually extremely low. To prevent blindness, adherence to treatment needs to improve, using acceptable, replicable and cost-effective interventions. After reviewing the literature and interviewing patients in Bauchi (Nigeria) motivational interviewing (MI) was selected as the intervention for this trial, with adaptation for glaucoma (MIG). MI is designed to strengthen personal motivation for, and commitment to a specific goal by eliciting and exploring a person's reasons for change within an atmosphere of acceptance and compassion. The aim of this study is to assess whether MIG increases the uptake of laser or surgery amongst glaucoma patients where this is the recommended treatment. The hypothesis is that MIG increases the uptake of treatment. This will be the first trial of MI in Africa.

METHODS

This is a hospital based, single centre, randomized controlled trial of MIG plus an information sheet on glaucoma and its treatment (the latter being "standard care") compared with standard care alone for glaucoma patients where the treatment recommended is surgery or laser.Those eligible for the trial are adults aged 17 years and above who live within 200 km of Bauchi with advanced glaucoma where the examining ophthalmologist recommends surgery or laser. After obtaining written informed consent, participants will be randomly allocated to MIG plus standard care, or standard care alone. Motivational interviewing will be delivered in Hausa or English by one of two MIG trained personnel. One hundred and fifty participants will be recruited to each arm. The primary outcome is the proportion of participants undergoing laser or surgery within two months of the date given to re attend for the procedure. MIG quality will be assessed using the validated MI treatment integrity scale.

DISCUSSION

Motivational interviewing may be an important tool to increase the acceptance of treatment for glaucoma. The approach is potentially scalable and may be useful for other chronic conditions in Africa.

TRIAL REGISTRATION

ISRCTN79330571 (Controlled-Trials.com).

Glaucoma subtypes in Ethiopian clinic patients

BACKGROUND

Until population-based data become available in Ethiopia, hospital-based studies may reflect the distribution of the subtypes of glaucoma in certain parts of the country.

PURPOSE

The main aim of this study was to determine the subtypes of glaucoma in Jimma University Hospital, Ethiopia.

METHODS

A facility-based cross-sectional study was conducted in Jimma University Hospital from April 1, 2007 to March 30, 2008. The study population consisted of 335 consecutive new and follow-up patients with glaucoma diagnosed based on strict objective criteria.

RESULTS

The mean (SD) age of the study patients was 57.0 (12.7) years (range, 8 to 90 y). The male to female ratio was 2.7:1. The 2 most common subtypes of glaucoma found were exfoliation glaucoma (35.2%) and primary open angle glaucoma (32.8%). Primary angle closure glaucoma was diagnosed in 18.5% of patients.

CONCLUSIONS

The finding of exfoliation glaucoma as the most common subtype of glaucoma in the present clinic-based study is interesting. Such observation has never been reported from anywhere in Africa. We recommend community-based surveys to define the real distribution of the glaucoma subtypes in Ethiopia.

The profile of glaucoma in a Tertiary Ophthalmic University Center in Riyadh, Saudi Arabia

PURPOSE

To report the pattern of glaucoma among Saudi patients who were presented to King Abdul Aziz University Hospital (KAUH).

METHODS

All glaucoma or glaucoma suspect patients who were presented to KAUH from 2006 to 2008 were included; medical files of all patients were retrieved and evaluated through standardized international guidelines. Collected data included: age, sex, laterality, intraocular pressure, and cup/disk ratio. Prevalence of different glaucoma types (including 95% CI) was calculated, ANOVA and post hoc tests were applied to evaluate the difference in indices across different types.

RESULTS

A total of 2296 eyes of 1236 patients were included. Primary angle closure glaucoma (PACG) was the predominant type (46.6%) followed by primary angle closure (PAC) (17.2%), then primary open angle glaucoma (POAG) (12.8%), and secondary glaucoma (13%). Other types including (normal tension glaucoma (5.9%), childhood glaucoma (2.6%), and juvenile glaucoma (1.9%)) were also present but of lower prevalence.

CONCLUSION

Primary angle closure glaucoma was the predominant form of glaucoma followed by PAC, and POAG suggesting that the pattern in Saudi Arabia could be quite different from that reported for primary glaucomas in the Western literature. In addition, pseudoexfoliation was the most common form of secondary open and closed angle glaucoma. These results indicate the need for a national intervention program for early detection and referral of glaucoma cases in order to prevent significant visual loss. There is also a need for a community based assessment to determine the prevalence of glaucoma as a baseline for future intervention.

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.

Primary Open-Angle Glaucoma Presentation at a Tertiary Unit in Africa: Intraocular Pressure Levels and Visual Status

AIM

To investigate the presentation of POAG at a tertiary referral hospital in East Africa, including intraocular pressures, visual status and management decisions.

METHODS

Retrospective review of first-time presenters with POAG over a 6-month period.

RESULTS

Of the 298 patients identified, mean age 57 years (n = 296, range = 14-88, SD = 14), 213 (72%) male, 122 (41%) had normal vision (using WHO better eye acuity criteria: visual impairment < 6/18, blind < 3/60) at presentation, 87 (30%) had visual impairment and 86 (29%) were blind. The mean presenting IOP was 32 mmHg (SD = 11) and 70% of the patients had a cup:disc ratio of 0.8 or worse in the better eye. Longer disease duration (OR = 1.20, 95% CI 1.04-1.39) and higher mean IOP (OR = 1.06, 95% CI 1.02-1.10) were associated with visual impairment or blindness. Intraocular pressure showed a negative linear correlation with presenting logMAR acuity (R(2) = 0.115, SE = 1.30, p < 0.0005). The mean IOP in eyes that had undergone trabeculectomy (19 mmHg, SD = 8, n = 17) was significantly (p < 0.0005) lower than that in eyes that had not (34 mmHg, SD = 12, n = 274). The referral rate for trabeculectomy was 158/275 (57%). Male sex (OR = 2.17, 95% CI 1.0-4.72), higher mean IOP (OR = 1.09, 95% CI 1.05-1.14) and not being blind (OR = 26.47, 95% CI 9.90-70.78) were associated with surgical referral. Of the 158 patients, 76 (48%) accepted surgery.

CONCLUSIONS

A high proportion of patients presenting to our unit with POAG are visually impaired or blind and the higher their presenting IOP the poorer their visual acuity. Previous trabeculectomy was associated with lower IOPs and protection from visual impairment and blindness. Further training of clinic staff towards early surgical referral and investigation of gender barriers is required.

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.

What is practical in glaucoma management?

This article addresses some important issues in the detection and management of glaucoma using examples from the developing world, particularly drawing on experiences and research in sub-Saharan Africa.

Role of early trabeculectomy in primary open-angle glaucoma in the developing world

BACKGROUND

The lack of prospective data comparing early surgery and medical management in primary open-angle glaucoma (POAG) in the developing world led us to conduct a small randomised controlled clinical trial to evaluate acceptance and effectiveness of early trabeculectomy in these patients.

METHODS

A total of 60 patients with moderately advanced POAG were randomised into three groups (Group I-Conventional medical management, Group II-Option for early trabeculectomy, Group III-Received an educational package about their disease before an option for early trabeculectomy). The patients were followed up for a period of 6 months for visual acuity, intraocular pressures (IOP), and subjective satisfaction.

RESULTS

The three study groups were statistically similar with respect to mean IOP, demographic, and socio-economic profile. 35% of the patients accepted early surgery when offered a choice between early surgery and medical management in one of the groups. 65% of patients in another group expressed willingness for an early surgery after receiving health education on glaucoma. The mean IOP in the operated eyes was lower than the medically treated eyes at 2 weeks (16.6 vs 23.0 mmHg), 6 months (18.5 vs 22.8 mmHg), and 1-year review (17.9 vs 22.3 mmHg) (P<0.001). No significant difference was seen among the groups with regard to visual acuity and subjective satisfaction.

CONCLUSION

There is a reasonable acceptance of early surgery in POAG patients in the developing world and increases on educating patients about their disease. Early surgery offers better IOP control with no long-term subjective adverse effects.

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

Intraoperative 5-fluorouracil application during primary trabeculectomy in Nigeria: a comparative study

PURPOSE

To investigate the effect on intraocular pressure (IOP) of intraoperative 5-fluorouracil (5-FU) application during primary trabeculectomy in a West African population.

METHODS

Retrospective case note search of operating theatre records for primary trabeculectomy between 1996 and 2000 in an eye hospital in Lagos, Nigeria. For statistical analysis, patients were divided into group that received intraoperative 5-FU (50 mg/ml for 5 min) and a control group that received no intraoperative antimetabolites. Patients with a follow-up of less than 6 months were excluded. For life-table analysis, only one eye from each patient was included to maintain independent analysis.

RESULTS

A total of 154 eyes of 101 patients were included in the study. Average follow-up was 17 +/- 2.18 (95% confidence interval) months. No significant difference was found between the groups for age, sex, preoperative medication, and follow-ups. Comparison of survival curves by the log-rank test showed that the probability of maintaining an IOP of 20 mm Hg or less at 18 months was 76% in the 5-FU group and 79% in the controls (P= 0.55). However, the probability of maintaining an IOP 14 mmHg or less was significantly greater in the 5-FU group (64%) than in the controls (39%, P=0.018). Visual acuity loss of more than two Snellen-chart lines was observed in six eyes (7.9%) of the 5-FU group and in four eyes (5.1%) of the control group and this difference was not significant (P=0.49, Fisher exact test). Complication rates were similar in each group.

CONCLUSIONS

In this population, intraoperative 5-FU application during trabeculectomy appears to improve probability of maintaining an intraocular pressure of 14 mmHg or less with no additional deleterious effects on the eye.

Primary open-angle glaucoma in blacks: a review

Glaucoma is one of the leading causes of blindness worldwide. Primary open-angle glaucoma (POAG) is the most prevalent form of glaucoma and has a particularly devastating impact in blacks. In the black American population, POAG prevalence is estimated to be six times as high in certain age groups compared to whites. POAG is more likely to result in irreversible blindness, appears approximately 10 years earlier and progresses more rapidly in blacks than in whites. Racial differences in optic disk parameters have been reported and show that blacks have larger optic disks than whites. This finding is robust and may account for the reported differences in other optic disk parameters. The existence of racial differences in intraocular pressure remains to be demonstrated, as conflicting findings are reported in the literature. Intraocular pressure may actually be underestimated in blacks, perhaps because they have thinner corneas. The prevalence of diabetes and hypertension is higher in blacks than in whites, and although no causal relationship has been established between POAG and each of these systemic diseases, some reports suggest that they often occur together, perhaps through an indirect relationship with intraocular pressure. Compounding the problem, there is evidence that blacks are less responsive to both drug and surgical treatment for POAG. Finally, they often have reduced accessibility to treatment and are less aware of the risks of having POAG. This article provides a comprehensive review of the current knowledge pertaining to POAG in blacks.

Temba glaucoma study: a population-based cross-sectional survey in urban South Africa

OBJECTIVE

To determine the prevalence and features of glaucoma in an urban South African black population.

DESIGN

Random sampling cross-sectional population survey.

PARTICIPANTS

Black residents of Temba, North West Province, South Africa, age > or =40 years.

MAIN OUTCOME MEASURES

Automated visual field testing and detailed, standardized slit-lamp examination were attempted on all subjects. Glaucoma was diagnosed by use of the scheme proposed by the Working Group for Defining Glaucoma of the International Society of Geographical and Epidemiologic Ophthalmology on the basis of evidence of end-organ damage.

RESULTS

Of 1120 subjects, 839 (74.9%) were examined. The age- and gender-adjusted prevalence of glaucoma of all types was 5.3% (95% confidence interval [CI], 3.9%-7.1%). Primary open-angle glaucoma (POAG) was the most common glaucoma diagnosis, with an adjusted prevalence of 2.9% (95% CI, 1.9%-4.3%). Secondary glaucoma occurred with an adjusted prevalence of 2.0% (95% CI, 1.2%-3.3%). Exfoliative glaucoma was responsible for 16% of all glaucoma cases. The prevalence of primary angle-closure glaucoma was 0.5% (95% CI, 0.13%-1.2%). Of all subjects with glaucoma, 58% were blind in at least one eye. The prevalence of all types of glaucoma increased with age. Of subjects with POAG, 87% had not been previously diagnosed.

CONCLUSIONS

The prevalence of glaucoma in this South African population was higher than that found in white populations, and most cases were undiagnosed and untreated. Glaucoma is a major cause of blindness in this population.

Prevalence of myocilin mutations in adults with primary open-angle glaucoma in Ghana, West Africa

PURPOSE

Investigators have noted that primary open-angle glaucoma (POAG) in West Africa has an earlier age of onset and appears to be more clinically severe than in the United States and Europe. Primary open-angle glaucoma patients with mutations in myocilin have a similar phenotype. Therefore, we investigated the role of mutations in myocilin in patients with POAG in a West African population.

MATERIALS AND METHODS

Patients seen at the Emmanuel Eye Clinic in Accra, Ghana, were recruited for this study. Informed consent was obtained from all study patients. Glaucoma specialists from the sponsoring institution (PC, LWH, or RRA) ascertained all POAG and control patients. Age-matched unaffected controls were obtained in patients with an IOP < 22 mm Hg and normal-appearing optic nerves. PCR amplification of each of the three myocilin exons was performed. Denaturing high-performance liquid chromatography (Transgenomics Corp.) was used to detect allelic differences and samples demonstrating a mobility shift were sequenced in both directions.

RESULTS

Ninety unrelated affecteds with POAG and 76 control patients were recruited. Four individuals with severe POAG were found to have novel missense mutations in exon 3. Two exhibit an Asp380Asn mutation and two an Arg342Lys mutation. These changes were not detected in 152 ethnically matched control chromosomes. Fourteen affected individuals and eight controls exhibit a translationally silent polymorphism in codon 325 (Thr325Thr).

CONCLUSIONS

A total of 4.4% of patients with POAG have novel disease-associated mutations in myocilin. Mutations in myocilin appear to play a limited role in the pathogenesis of POAG in this region of West Africa.

Survey of glaucoma in an eye clinic in Ghana, West Africa

PURPOSE

To report the various types of glaucoma among West African patients presenting to an eye clinic in Ghana.

METHODS

A complete evaluation was performed in 198 consecutive Ghanaian glaucoma patients. Main outcome measures included intraocular pressure, visual acuity, gonioscopy findings, visual field, and total number of glaucoma medications.

RESULTS

The most common form of glaucoma was primary open-angle glaucoma (44.2%). Open-angle glaucoma suspects also comprised a large percentage of the group (30.5%). Chronic angle-closure glaucoma was diagnosed in 6.6% of the patients.

CONCLUSIONS

Primary open-angle glaucoma is the most common form of glaucoma being treated in this outpatient eye clinic in Ghana. Chronic angle-closure glaucoma was the second most common form of glaucoma in this series and was usually undiagnosed due to a lack of gonioscopic evaluation. Gonioscopy is an important diagnostic tool that should be promoted to guide more effective glaucoma treatment in this region. Pseudoexfoliation and pseudoexfoliation-associated glaucoma were not seen in this population.

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.

Glaucoma in West Africa: a neglected problem

Glaucoma in sub-Saharan Africa is a devastating disease which has not been fully addressed by the global ophthalmology community. The key issue is the lack of a satisfactory treatment.

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.

Glaucoma care in West Africa

The authors draw on the peer review literature and 8 years of personal experience to provide an overview of the prevalence and management of glaucoma in West Africa.

Blindness in Africa: present situation and future needs

AIM

To review the prevalence and causes of blindness in sub-Saharan Africa, the existing services and limitations, and the Vision 2020 goals for the future.

METHODS

Methodologically sound population based surveys published in the past 20 years are reviewed and results for prevalence and causes of blindness are tabulated. The current resources and needs according to recent publications and international working groups are described.

CONCLUSIONS

Blindness prevalence rates vary widely but the evidence suggests that approximately 1% of Africans are blind. The major cause is cataract; trachoma and glaucoma are also important causes of blindness. The bulk of blindness in the region is preventable or curable. Efforts should focus on eye problems which are universally present and for which there are cost effective remedies, such as cataract and refractive problems and on those problems which occur focally and can be prevented by primary healthcare measures, such as trachoma, onchocerciasis, and vitamin A deficiency. Major development of staffing levels, infrastructure, and community programmes will be necessary to achieve Vision 2020 goals.

Trabeculectomy outcomes in advanced glaucoma in Nigeria

BACKGROUND

Trabeculectomy remains the mainstay of therapy for advanced glaucoma in Nigeria due to the unavailability and expense of topical therapy. Little is known of the medium- to long-term outcomes of trabeculectomy in West Africa. Purpose To retrospectively assess outcomes, in terms of lowering of the intraocular pressure and preserving the visual acuity, and the safety of trabeculectomy in patients with advanced glaucoma in Nigeria.

METHODS

A retrospective case-note search was carried out from operating theatre records in a private hospital at Lagos, Nigeria from 1989 to 1997. Patients undergoing primary trabeculectomy with a minimum follow-up of 6 months were included in the study. Visiting consultants and registrars from the UK performed the surgery. Descriptive statistics and life-table analysis were applied to the data.

RESULTS

One hundred and forty-two eyes of 100 patients were included in the study. When the criteria for success were an intraocular pressure (IOP) of less than 22 mmHg, 30% reduction from pre-operative levels and a decrease in visual acuity of less than 3 Snellen chart lines, then by life-table analysis success rates were 85%, 82% and 71% at the 1, 2 and 5 year post-operative intervals respectively. Success rates were lower if an IOP of less than 16 mmHg was taken as one of the criteria (65%, 61% and 46% at the 1, 2 and 5 year intervals, respectively).

CONCLUSIONS

Trabeculectomy without antimetabolite use appears to be an effective way to lower the IOP of advanced glaucoma patients in Nigeria to less than 22 mmHg but not to less than 16 mmHg. The procedure, in experienced hands, is relatively safe with few major complications.

Long term results of glaucoma surgery among participants in an east African population survey

AIM

To evaluate the long term results of glaucoma surgery among people in East Africa.

METHODS

Participants in a population based survey of eye disease prevalence were offered glaucoma surgery using standardised criteria. Either surgical iridectomy or trabeculectomy was carried out as indicated by a medical officer or by one of two ophthalmologists. Trabeculectomy methods included releasable sutures and mitomycin C in the majority of eyes. Subjects were examined during the first week and 2 months after surgery. Nearly 3 years later, re-examination was carried out in those who were still resident in the region.

RESULTS

Among 46 people who were offered iridectomy, trabeculectomy, or combined cataract extraction/lens implant/trabeculectomy, 21 people underwent surgery (46%). Of the 21, 19 were re-examined at 3 years (90%), including 16/18 eyes after trabeculectomy. Among these, intraocular pressure (IOP) declined from 29.9 (SD 9.4) mm Hg to 14.7 (5.9) mm Hg, with 16 of 18 eyes (89%) achieving a reduction > 25%. Hypotony maculopathy, late bleb leak, and late endophthalmitis were not detected. Visually significant cataract developed in 5/15 re-examined eyes that underwent trabeculectomy alone (33%), possibly associated with pre-existing cataract and diagnosis of angle closure glaucoma, but not with mitomycin C use.

CONCLUSIONS

Nearly half of those with glaucoma among residents of rural African villages accepted the offer of surgical therapy. While technical success was achieved at satisfactory levels, the development of cataract must be considered an important issue for application of glaucoma surgical therapy programmes.

Schiotz tonometry for glaucoma: are there simple alternatives?

In the period from October 1991 until August 1992, 864 eye-patients in a rural area in south-east Nigeria were examined in order to find simple parameters for the screening of glaucoma simplex. Schiotz tonometry was used as the gold standard. Investigation of the pupil-reaction with a torch, estimation of the pressure of the (closed) eye by digital palpation, and estimations of the cup/disc ratio by ophthalmoscopy can be used as an alternative.

Racial differences in the results of glaucoma filtration surgery: are racial differences in the conjunctival cell profile important?

Conjunctival biopsies were obtained at the time of filtration surgery from 90 patients with glaucoma; 45 of these patients were black and 45 white. Forty nine of the patients (25 black, 24 white) had undergone a primary trabeculectomy. Comparisons between black and white patients were made with respect to the results of surgery and differences in conjunctival cell profile. In agreement with many authors, trabeculectomy was found to be less successful in black patients (67% compared with 80%), although this finding was not statistically significant by survival analysis. In addition, conjunctiva from black patients was found to contain a greater number of macrophages and a smaller number of both mast cells and goblet cells in comparison with white patients. There was a tendency for conjunctiva from black patients to contain more fibroblasts. Conjunctiva obtained from the patients whose filtration surgery subsequently failed was found to contain more fibroblasts, macrophages, and basal epithelial pale cells. A greater number of conjunctival macrophages and possibly fibroblasts in black patients may partially explain the tendency for a lower success rate of filtration surgery in this group of patients.

Prevalence of blindness and low vision of people over 30 years in the Wenchi district, Ghana, in relation to eye care programmes

A population based survey on the prevalence of major blinding disorders was conducted in the Wenchi district in central Ghana between March and May 1991. In 10 villages, 1425 people of 30 years and older were screened, using the WHO eye examination record. The prevalence of bilateral blindness above 30 years proved to be 1.7% (best acuity < 3/60): the prevalence of low vision above 30 years was 2.0% (best visual acuity 6/18 to 3/60). The causes of blindness were determined as cataract (62.5%), onchocerciasis (12.5%), corneal opacity (non-trachomatous) (8.2%), refraction anomalies (4.2%), phthisis bulbi (4.2%), optic atrophy (4.2%), and vascular retinopathy (4.2%). In the Wenchi district, 1.0% of the population over the age of 30 years was found to need a cataract extraction because of blindness of both eyes. Another potential 1.0% needs a cataract extraction because of low vision. A minor second study (n = 149) was undertaken in the same district, but in a village in an area near the Black Volta river in which onchocerciasis is endemic. The prevalence of blindness (8.1%) and low vision (3.4%) caused by onchocerciasis and cataract both proved to be higher. The survey provided the basis for a preventive and curative eye care programme.

Young patient trabeculectomy. Assessment of risk factors for failure

BACKGROUND

Various risk factors for failure of glaucoma filtering surgery, including young age, have been suggested.

METHODS

A retrospective study of 113 trabeculectomies in 113 patients, ranging in age between 11 and 49 years (mean, 33.3 +/- 10.5 years), was carried out to determine the influence of these risk factors in young patients.

RESULTS

A successful outcome (intraocular pressure [IOP] < or = 21 mmHg without antiglaucoma treatment), assessed by life-table analysis, was achieved in 54% of trabeculectomies after 38 months (mean follow-up, 36.7 +/- 29.7 months). Previous ocular surgery (e.g., glaucoma filtering, cataract, or conjunctival surgery) and previous laser therapy (i.e., argon laser trabeculoplasty and YAG laser iridotomy) both significantly reduced the success rate. An IOP greater than 40 mmHg during the course of the disease was found to adversely affect the outcome. No direct correlation between success rate and age and no racial difference were demonstrated. Success rates for specific diagnoses were not significantly different. Postoperative subconjunctival injections of 5-fluorouracil (5-FU) did not significantly improve the success rate. A Cox regression analysis of various prognostic variables identified previous cataract surgery (hazard ratio, 4.4), argon laser trabeculoplasty (hazard ratio, 3.4), previous glaucoma filtering surgery (hazard ratio, 2.5), nonfiltering glaucoma surgery (hazard ratio, 2.2) and IOP greater than 40 mmHg (hazard ratio, 2.4) to be the major risk factors for glaucoma filtering surgery failure.

CONCLUSION

A majority (74%) of the patients in our series had at least one of these risk factors, thus explaining why young patients, in general, have lower success rates for trabeculectomy.

Points of action in the campaign against blindness in developing countries

This article provides a survey of the problems of prevention of blindness in developing countries. The World Health Organization estimates that 31 million people are blind and 15 million people partially-sighted. The main cause of blindness is cataract. Other causes are trachoma, glaucoma, xerophthalmia, river blindness, corneal scars and leprosy. Prevention or treatment of these causes is possible in more than 80% of cases. The number of blind persons, however, is still increasing due to the increase in population and the immense shortage of all kinds of ophthalmological equipment and personnel. An effective strategy for the prevention of blindness in developing countries should focus on: more cheap cataract operations, increasing teaching facilities for ophthalmic personnel, integration of ophthalmic care into the general health system and the promotion of blindness prevention in political organizations.

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

Of 34 consecutive patients with chronic glaucoma seen in north-east Ghana, 22 (65%) were male and seven (21%) were aged under 40 years. Only 17% of eyes had a visual acuity better than 6/18 at presentation. Sixteen of 23 patients who underwent gonioscopy had PAS of which 13 had positive skin snips for onchocerciasis, compared with two out of seven patients with positive skin snips who had open angle glaucoma (p = 0.003). Of 22 trabecular meshworks examined by light microscopy ten (45%) showed marked melanin pigmentation which was more common in younger patients but did not correlate with onchocerciasis infection.