Improving survival of retinoblastoma in Uganda.

BACKGROUND: Diagnostic delay results in relatively high mortality among children with retinoblastoma in Uganda, where treatment was limited to surgery and, for some, radiotherapy. In order to improve outcomes, a simple programme of neoadjuvant and adjuvant chemotherapy was introduced. Here we report survival before and after this change to medical practice. METHODS: Affordable standard off-patent chemotherapy agents were administered by trained paramedical staff to groups of patients at the same time. Survival before and after the introduction of chemotherapy was monitored. Between 2006 and 2013 a total of 270 patients with retinoblastoma were included, 181 treated prior to chemotherapy and 89 after (beginning in 2009). We had 94% follow-up and 249 had histological verification of diagnosis. RESULTS: Using a proportional hazards model adjusted for age, sex and laterality, children treated after chemotherapy was introduced had a 37% lower risk of dying (HR 0.63, 95% CI 0.41 to 0.99) compared with children treated before. Prior to the introduction of chemotherapy only 15% of children who survived bilateral disease retained vision after treatment compared with 71% after chemotherapy. CONCLUSIONS: The introduction of chemotherapy proved safe and cost-effective in non-specialist hands and was associated with significant improvements in survival and, among bilateral cases, in preserving vision.

Clinical features and survival among children with retinoblastoma in Uganda.

AIMS: To characterise the clinical features, treatment and outcome of children diagnosed with retinoblastoma in Uganda. METHODS: The study comprised a 6-year nationwide enrolment with follow-up. RESULTS: In total, 282 cases were enrolled, 26% (72) were bilateral; 6% were lost to follow-up. Almost all diagnoses in the first affected eye were International Classification of Retinoblastoma group E or worse. Histology was available for 92%; of those, 45%, had extraocular tumour at diagnosis. Enucleation of the first eye was done for 271; 94 received radiotherapy to the socket and in the last 2 years, 70 children received chemotherapy. At close of study, 139 children had died. Survival, as determined in a proportional hazards model adjusted for age, sex, laterality and treatment era (pre or post introduction of chemotherapy), varied by extent of the tumour (p<0.001); children with only intraocular involvement were 80% less likely to die (HR=0.21, 95% CI 0.12 to 0.35) compared with children with extraocular involvement. CONCLUSIONS: Diagnostic delay results in relatively high mortality among children with retinoblastoma in Uganda. There is an urgent need for more effective treatment modalities, particularly chemotherapy, and nationwide efforts to encourage earlier access to medical care.

Ethnic and mouse strain differences in central corneal thickness and association with pigmentation phenotype.

The cornea is a transparent structure that permits the refraction of light into the eye. Evidence from a range of studies indicates that central corneal thickness (CCT) is strongly genetically determined. Support for a genetic component comes from data showing significant variation in CCT between different human ethnic groups. Interestingly, these studies also appear to show that skin pigmentation may influence CCT. To validate these observations, we undertook the first analysis of CCT in an oculocutaneous albinism (OCA) and Ugandan cohort, populations with distinct skin pigmentation phenotypes. There was a significant difference in the mean CCT of the OCA, Ugandan and Australian-Caucasian cohorts (Ugandan: 517.3±37 µm; Caucasian: 539.7±32.8 µm, OCA: 563.3±37.2 µm; p<0.001). A meta-analysis of 53 studies investigating the CCT of different ethnic groups was then performed and demonstrated that darker skin pigmentation is associated with a thinner CCT (p<0.001). To further verify these observations, we measured CCT in 13 different inbred mouse strains and found a significant difference between the albino and pigmented strains (p = 0.008). Specific mutations within the melanin synthesis pathway were then investigated in mice for an association with CCT. Significant differences between mutant and wild type strains were seen with the nonagouti (p<0.001), myosin VA (p<0.001), tyrosinase (p = 0.025) and tyrosinase related protein (p = 0.001) genes. These findings provide support for our hypothesis that pigmentation is associated with CCT and identifies pigment-related genes as candidates for developmental determination of a non-pigmented structure.