XEN®-45 implantation for refractory uveitic glaucoma.

PURPOSE: To evaluate the efficacy of XEN®-45 gel stent ab interno implantation for medically uncontrolled uveitic glaucoma. METHODS: Retrospective analysis of 25 eyes receiving XEN® gel stent for medically uncontrolled uveitic glaucoma from February 2019 to February 2023 with recording of intraocular pressure (IOP) values, ocular hypotensive medication, requirement for revision or secondary surgery and complications. Prerequisites for XEN® implantation were a clear cornea, an open iridocorneal angle and an unscarred, mobile conjunctiva at the implantation site. Minimum follow-up required for inclusion was 3 months. The primary outcome measure was IOP compared to baseline. Complete and qualified success were defined as final IOP of ≤ 18 mmHg without or with topical antiglaucomatous treatment, respectively. Failure was defined as IOP > 18 mmHg on two consecutive visits, IOP reduction < 20%, persisting complications from hypotony and open conjunctival bleb revision. Further glaucoma surgical intervention was defined as complete failure. RESULTS: Mean preoperative IOP was 35.3 ± 10.9 mmHg on 2.9 ± 0.9 topical antiglaucomatous agents. 19 of 25 patients (76%) received additional oral acetazolamide. 19 eyes were pseudophakic, 5 eyes phakic and 1 aphakic. Early postoperatively, mean IOP reduced to 7.7 ± 3.0 mmHg (75.8% reduction). At final follow-up (mean 17.7 months) mean IOP was 12.0 ± 3.8 mmHg (62.5% reduction) on 0.2 ± 0.6 medications. Six eyes (24%) required bleb revision at mean 28 weeks and therefore were categorized as failure. One eye failed despite bleb revision and restart of topical ocular hypotensive medication. Three other eyes (12%) had IOP spikes with uveitis flare-ups. Transient hypotony complications occurred in 32%. At final follow-up, 18 eyes (72%) achieved complete success and one eye (4%) qualified success. CONCLUSION: The XEN® gel stent effectively reduced IOP in uncontrolled uveitic glaucoma, with 72% complete success. Bleb revision was required in 24%. IOP spikes occurred in 12% despite functioning blebs. Further follow-up is needed to determine long-term outcomes.

Diabetic retinopathy in Tanzania: prevalence and risk factors at entry into a regional screening programme.

OBJECTIVE: The number of adults with diabetes in sub-Saharan Africa (SSA) is expected to almost double by 2035. This study investigated the prevalence of diabetic retinopathy (DR) and its risk factors at entry into a community-based screening programme. METHODS: All persons with diabetes screened for retinopathy at entry into a screening programme in Kilimanjaro Region, Tanzania between November 2010 and December 2014 were included. Fundus photographs were taken with a Topcon retinal camera following pupil dilation. Data were collected on BP, random blood sugar, duration of diabetes, BMI and visual acuity on entry. RESULTS: A total of 3187 persons were screened for DR. The prevalence of any DR was 27.9% (95%CI 26.4-29.5%) with background diabetic retinopathy (BDR), pre-proliferative diabetic retinopathy (PPDR) and proliferative diabetic retinopathy (PDR) having a prevalence of 19.1% (95% CI 17.7-20.4%), 6.0% (95%CI 5.2-6.8%) and 2.9% (95%CI 2.3-3.5%), respectively. Maculopathy was present in 16.1% (95%CI 14.8-17.4%) of participants. Multivariable logistic regression analysis for the presence of any DR found independent associations with duration of diabetes (P < 0.0001), systolic BP (P < 0.0001), random blood sugar (P < 0.0001) and attending a government hospital diabetic clinic (P = 0.0339). CONCLUSIONS: This study is the first to present data from a DR screening programme in SSA. The results will provide policymakers with data to aid planning of DR screening and treatment services in the African region. The study highlights the importance of managing comorbidities within DR screening programmes.

Reasons for poor follow-up of diabetic retinopathy patients after screening in Tanzania: a cross-sectional study.

BACKGROUND: Diabetes is an emerging public health problem in sub-Saharan Africa. Diabetic retinopathy is the commonest microvascular complication of diabetes and is a leading cause of blindness, mainly in adults of working age. Follow-up is crucial to the effective management of diabetic retinopathy, however, follow-up rates are often poor in sub-Saharan Africa. The aim of this study was to assess the proportion of patients not presenting for follow-up and the reasons for poor follow-up of diabetic patients after screening for retinopathy in Kilimanjaro Region of Tanzania. METHODS: All diabetic patients referred to a tertiary ophthalmology hospital after screening for retinopathy in 2012 were eligible for inclusion in the study. A randomly selected group of patients from the community-based diabetic retinopathy screening register were identified; among this group, follow-up was assessed. Interviews were conducted within this group to inform on the reasons for poor follow-up. RESULTS: Among the 203 patients interviewed in the study 50 patients (24.6 %) attended the recommended referral appointment and 153 (75.4 %) did not. Financial reasons were self-reported by 35.3 % of those who did not attend the follow-up appointment as the reason for non-attendance. Multiple logistic regression analysis showed that the patient report of the clarity of the referral process (p = 0.014) and the patient report of whether a healthcare worker told the patient that diabetic retinopathy could be treated (p = 0.005) were independently associated with attendance at a follow-up appointment. Income per month was not associated with attendance at a follow-up appointment on multivariate analysis. CONCLUSIONS: Financial factors are commonly cited as the reason for non-compliance with follow-up recommendations. However, the reasons for poor compliance are likely to be more complicated. This study highlights the importance of health system factors. Improving the clarity of the referral process and frequent reminders to patients that diabetic retinopathy can be treated are practical strategies that should be incorporated into screening programmes to increase attendance at subsequent follow-up appointments. The results from this study are applicable to other screening programmes as well as those for diabetic retinopathy.

Glaucoma awareness and access to healthcare: perceptions among glaucoma patients in Tanzania.

OBJECTIVE: To investigate the barriers to access to eye health services for patients with glaucoma in Tanzania with the aim of identifying key areas for improvement and further research. DESIGN: Qualitative investigation using face-to-face semi-structured interviews with patients recruited from the Kilimanjaro Christian Medical Centre (KCMC) outpatient eye clinic. This project is part of the international strategy of the Research into Glaucoma and Ethnicity (ReGAE) programme. METHODS: Interviews were conducted with the help of a translator; all data were transcribed in Swahili and then translated into English. Manual coding and qualitative analysis was used to identify major themes and relevant concepts. Data were collected during May and June 2013. MAIN OUTCOME MEASURES: Qualitative data on glaucoma awareness and access to healthcare. RESULTS: 12 patients (7 men, 5 women) of mean age 67.5 years (range 53-86 years) were interviewed. All participants had a previous diagnosis of glaucoma and no other eye conditions. The understanding of glaucoma was limited and the capacity for healthcare providers to improve glaucoma knowledge seemed underused. Participants had particular difficulty in understanding the aetiology and chronicity of the disease. Socioeconomic factors also posed significant barriers to service usage. CONCLUSIONS: Among many barriers to access to health services for patients with glaucoma, knowledge of the condition was identified as a key issue. Enhancing the understanding of glaucoma may improve access by triggering earlier presentation, informing those at risk and improving adherence to treatment. This is an area for further research with potential for improving service provision.

[Global ophthalmology : Update]. / Globale Ophthalmologie : Aktueller Stand.

The aim of global ophthalmology is to maximize vision, ocular health and functional ability, thereby contributing to overall health and well-being, social inclusion and quality of life of every individual worldwide. Currently, an estimated 1.1 billion people live with visual impairment, 90% of which can be prevented or cured through largely cost-effective interventions. At the same time, 90% of people affected live in regions with insufficient eye health coverage. This challenge drove the World Health Organization (WHO) and a group of nongovernmental organizations to launch "VISION 2020: the Right to Sight", a global campaign which recently concluded after 20 years. The achievements, challenges and lessons learned were identified and incorporated into the current campaign "2030 IN SIGHT".

Artificial intelligence-supported diabetic retinopathy screening in Tanzania: rationale and design of a randomised controlled trial.

INTRODUCTION: Globally, diabetic retinopathy (DR) is a major cause of blindness. Sub-Saharan Africa is projected to see the largest proportionate increase in the number of people living with diabetes over the next two decades. Screening for DR is recommended to prevent sight loss; however, in many low and middle-income countries, because of a lack of specialist eye care staff, current screening services for DR are not optimal. The use of artificial intelligence (AI) for DR screening, which automates the grading of retinal photographs and provides a point-of-screening result, offers an innovative potential solution to improve DR screening in Tanzania. METHODS AND ANALYSIS: We will test the hypothesis that AI-supported DR screening increases the proportion of persons with true referable DR who attend the central ophthalmology clinic following referral after screening in a single-masked, parallel group, individually randomised controlled trial. Participants (2364) will be randomised (1:1 ratio) to either AI-supported or the standard of care DR screening pathway. Participants allocated to the AI-supported screening pathway will receive their result followed by point-of-screening counselling immediately after retinal image capture. Participants in the standard of care arm will receive their result and counselling by phone once the retinal images have been graded in the usual way (typically after 2-4 weeks). The primary outcome is the proportion of persons with true referable DR attending the central ophthalmology clinic within 8 weeks of screening. Secondary outcomes, by trial arm, include the proportion of persons attending the central ophthalmology clinic out of all those referred, sensitivity and specificity, number of false positive referrals, acceptability and fidelity of AI-supported screening. ETHICS AND DISSEMINATION: The London School of Hygiene & Tropical Medicine, Kilimanjaro Christian Medical Centre and Tanzanian National Institute of Medical Research ethics committees have approved the trial. The results will be submitted to peer-reviewed journals for publication. TRIAL REGISTRATION NUMBER: ISRCTN18317152.

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.

XEN®-63 Compared to XEN®-45 Gel Stents to Reduce Intraocular Pressure in Glaucoma.

The XEN® gel stent reduces intraocular pressure (IOP) in glaucoma. XEN®-45 is widely used; the newer XEN®-63 has a larger lumen targeting potentially lower IOP outcomes. We retrospectively compared the first 15 XEN®-63 cases to 15 matched XEN®-45 controls. With a preoperative IOP of 18.1 ± 3.9 mmHg (mean ± SD) and a final IOP of 9.1 ± 2.0 mmHg, XEN®-63 implantation resulted in an IOP reduction of 44.6 ± 16.5%. Similarly, with a preoperative IOP of 18.3 ± 4.5 mmHg and a final IOP of 10.3 ± 2.1 mmHg, XEN®-45 implantation resulted in an IOP reduction of 40.1 ± 17.2%. The median follow-up period was 204 days (range 78-338 days) for the XEN®-63 group and 386 days (range 99-1688 days) for the XEN®-45 group. In total, 5/15 eyes of each group underwent open conjunctival bleb revision within the period of observation. Three eyes of the XEN®-63 group had secondary glaucoma surgery. One eye in the XEN®-63 group and three eyes in the XEN®-45 group required a restart of antiglaucomatous medication. In conclusion, both stents effectively lower IOP and medication. XEN®-63 achieved a slightly lower IOP over a short follow-up. Complication and revision rates were similar.

The Impact of Simulation-Based Trabeculectomy Training on Resident Core Surgical Skill Competency.

PRCIS: Simulation-based surgical education shows a positive, immediate, and sustained impact on core surgical skill competency in trabeculectomy among resident ophthalmologists in training. PURPOSE: To measure the impact of trabeculectomy, surgical simulation training on core surgical skill competency in resident ophthalmologists. MATERIALS AND METHODS: This is a post hoc analysis of the GLAucoma Simulated Surgery trial, which is a multicenter, multinational randomized controlled trial. Resident ophthalmologists from 6 training centers in sub-Saharan Africa (in Kenya, Uganda, Tanzania, Zimbabwe, and South Africa) were recruited according to the inclusion criteria of having performed zero surgical trabeculectomies and assisted in <5. Participants were randomly assigned to intervention and control arms using allocation concealment. The intervention was a 1-week intensive trabeculectomy surgical simulation course. Outcome measures were mean surgical competency scores in 8 key trabeculectomy surgical skills (scleral incision, scleral flap, releasable suturing, conjunctival suturing, sclerostomy, tissue handling, fluidity, and speed), using a validated scoring tool. RESULTS: Forty-nine residents were included in the intention-to-treat analysis. Baseline characteristics were balanced between arms. Median baseline surgical competency scores were 2.88/16 [interquartile range (IQR): 1.75-4.17] and 3.25/16 (IQR: 1.83-4.75) in the intervention and control arms, respectively. At primary intervention, median scores increased to 11.67/16 (IQR: 9.58-12.63) and this effect was maintained at 3 months and 1 year ( P =0.0001). Maximum competency scores at primary intervention were achieved in the core trabeculectomy skills of releasable suturing (n=17, 74%), scleral flap formation (n=16, 70%), and scleral incision (n=15, 65%) compared with scores at baseline. CONCLUSIONS: This study demonstrates the positive impact of intensive simulation-based surgical education on core trabeculectomy skill development. The rapid and sustained effect of resident skill acquisition pose strong arguments for its formal integration into ophthalmic surgical education.

Gender bias within a diabetic retinopathy screening programme in Tanzania.

BACKGROUND: The Kilimanjaro Diabetic Programme has been running since 2010 and screens persons with diabetes for diabetic retinopathy (DR). It was noted that women were less likely to attend follow-up appointments compared to men. The aim of this study was to explore gender biases amongst persons registered with the screening programme. METHODS: A prospective mixed-methods study was carried out using a questionnaire of closed-ended questions and a semi-structured interview guide. RESULTS: Of the 300 participants included in the quantitative component of the study, 193 (64.3%) were female and 107 (35.7%) were male. Females were significantly less educated (p < 0.001) and self-reported as less likely to attend the tertiary hospital if referred (p = 0.022). Of the married participants, on multivariate analysis, men were significantly more likely to make both financial decisions in the household (p = 0.001) and to decide if, and when, family members should attend hospital compared to women (p = 0.0048), independent of age, education level and whether they were from an urban or rural area. Qualitative analysis of the 33 interviews revealed a good understanding of the threat to vision from DR, but limited appreciation of disease chronicity. A common theme was that men are regarded as the head of the household and therefore make the financial decisions; this was especially true in less educated families. CONCLUSION: As screening and treatment facilities for DR are developed in SSA, it is important that strategies are employed to reduce the burden of blindness and visual impairment from the under-utilisation of diabetic eye care services by women.

Simulation-based surgical education for glaucoma versus conventional training alone: the GLAucoma Simulated Surgery (GLASS) trial. A multicentre, multicountry, randomised controlled, investigator-masked educational intervention efficacy trial in Kenya, South Africa, Tanzania, Uganda and Zimbabwe.

BACKGROUND/AIM: Glaucoma accounts for 8% of global blindness and surgery remains an important treatment. We aimed to determine the impact of adding simulation-based surgical education for glaucoma. METHODS: We designed a randomised controlled, parallel-group trial. Those assessing outcomes were masked to group assignment. Fifty-one trainee ophthalmologists from six university training institutions in sub-Saharan Africa were enrolled by inclusion criteria of having performed no surgical trabeculectomies and were randomised. Those randomised to the control group received no placebo intervention, but received the training intervention after the initial 12-month follow-up period. The intervention was an intense simulation-based surgical training course over 1 week. The primary outcome measure was overall simulation surgical competency at 3 months. RESULTS: Twenty-five were assigned to the intervention group and 26 to the control group, with 2 dropouts from the intervention group. Forty-nine were included in the final intention-to-treat analysis. Surgical competence at baseline was comparable between the arms. This increased to 30.4 (76.1%) and 9.8 (24.4%) for the intervention and the control group, respectively, 3 months after the training intervention for the intervention group, a difference of 20.6 points (95% CI 18.3 to 22.9, p<0.001). At 1 year, the mean surgical competency score of the intervention arm participants was 28.6 (71.5%), compared with 11.6 (29.0%) for the control (difference 17.0, 95% CI 14.8 to 19.4, p<0.001). CONCLUSION: These results support the pursuit of financial, advocacy and research investments to establish simulation surgery training units and courses including instruction, feedback, deliberate practice and reflection with outcome measurement to enable trainee glaucoma surgeons to engage in intense simulation training for glaucoma surgery. TRIAL REGISTRATION NUMBER: PACTR201803002159198.

Selective laser trabeculoplasty versus 0·5% timolol eye drops for the treatment of glaucoma in Tanzania: a randomised controlled trial.

BACKGROUND: Glaucoma is a major cause of sight loss worldwide, with the highest regional prevalence and incidence reported in Africa. The most common low-cost treatment used to control glaucoma is long-term timolol eye drops. However, low adherence is a major challenge. We aimed to investigate whether selective laser trabeculoplasty (SLT) was superior to timolol eye drops for controlling intraocular pressure (IOP) in patients with open-angle glaucoma. METHODS: We did a two-arm, parallel-group, single-masked randomised controlled trial at the Eye Department of Kilimanjaro Christian Medical Centre, Moshi, Tanzania. Eligible participants (aged ≥18 years) had open-angle glaucoma and an IOP above 21 mm Hg, and did not have asthma or a history of glaucoma surgery or laser. Participants were randomly assigned (1:1) to receive 0·5% timolol eye drops to administer twice daily or to receive SLT. The primary outcome was the proportion of eyes from both groups with treatment success, defined as an IOP below or equal to target pressure according to glaucoma severity, at 12 months following randomisation. Re-explanation of eye drop application or a repeat SLT was permitted once. The primary analysis was by modified intention-to-treat, excluding participants lost to follow-up, using logistic regression; generalised estimating equations were used to adjust for the correlation between eyes. This trial was registered with the Pan African Clinical Trials Registry, number PACTR201508001235339. FINDINGS: 840 patients were screened for eligibility, of whom 201 (24%) participants (382 eligible eyes) were enrolled between Aug 31, 2015, and May 12, 2017. 100 (50%) participants (191 eyes) were randomly assigned to the timolol group and 101 (50%; 191 eyes) to the SLT group. After 1 year, 339 (89%) of 382 eyes were analysed. Treatment was successful in 55 (31%) of 176 eyes in the timolol group (16 [29%] of 55 eyes required repeat administration counselling) and in 99 (61%) of 163 eyes in the SLT group (33 [33%] of 99 eyes required repeat SLT; odds ratio 3·37 [95% CI 1·96-5·80]; p<0·0001). Adverse events (mostly unrelated to ocular events) occurred in ten (10%) participants in the timolol group and in eight (8%) participants in the SLT group (p=0·61). INTERPRETATION: SLT was superior to timolol eye drops for managing patients with open-angle high-pressure glaucoma for 1 year in Tanzania. SLT has the potential to transform the management of glaucoma in sub-Saharan Africa, even where the prevalence of advanced glaucoma is high. FUNDING: Christian Blind Mission, Seeing is Believing Innovation Fund, and the Wellcome Trust. TRANSLATIONS: For the Kiswahili, French and Portuguese translations of the abstract see Supplementary Materials section.

Referral patterns of children with glaucoma and their caretakers in Northern Tanzania.

AIM: To describe the referral patterns of children with primary childhood glaucoma (PCG) or secondary childhood glaucoma (SCG) and their presenting symptoms in Northern Tanzania. METHODS: A retrospective observational study of children <17y with PCG or SCG who were referred to Kilimanjaro Christian Medical Centre (KCMC) Eye Department between 2000 and 2013 was conducted. Presenting symptoms, age at presentation, place of origin, distance to hospital, type of glaucoma, visual acuity, optic disc appearance (vertical cup-to-disc ratio) and type of referral were described. RESULTS: Seventy patients with PCG and 27 patients with SCG were included in the study. Median age at first presentation was 1y in the PCG group (range 0-16y) and 9y in the SCG group (range 1-15y). In both groups around 87% of the children presented already with low vision (logMAR>0.48, better eye). Most of the children (60%) and their caretakers presented on their own initiative, while 24% were sent by different general health cadres and 16% by eye care professionals. Buphthalmos was the main symptom mentioned as a trigger for presentation. CONCLUSION: The study shows that most of the children presented late resulting in advanced stages of glaucoma at the time of initiation of treatment. The majority attended the referral eye department on their own initiative with buphthalmos being the most commonly described symptom. Awareness creation among caretakers of children, general health and eye care providers, ideally embedded in general child health promotion activities, is needed to increase and accelerate referrals.

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% {CI95%: 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.