Retinoblastoma - A comprehensive review, update and recent advances.

Retinoblastoma is the most common pediatric ocular malignancy. It is triggered by a biallelic mutation in the RB1 gene or MYCN oncogene amplification. Retinoblastomas can be unilateral (60%-70%) or bilateral (30%-40%); bilateral tumors are always heritable and present at an earlier age as compared to unilateral ones (18-24 months vs. 36 months in India). High prevalence rates, delayed presentation, and inaccessibility to healthcare lead to worse outcomes in developing countries. The past few decades have seen a paradigm change in the treatment of retinoblastomas, shifting from enucleation and external beam radiotherapy to less aggressive modalities for eye salvage. Multimodality treatment is now the standard of care and includes intraarterial or intravenous chemotherapy along with focal consolidation therapies such as transpupillary thermotherapy, cryotherapy, and laser photocoagulation. Intravitreal and intracameral chemotherapy can help in controlling intraocular seeds. Advanced extraocular or metastatic tumors still have a poor prognosis. Genetic testing, counseling, and screening of at-risk family members must be incorporated as essential parts of management. A better understanding of the genetics and molecular basis of retinoblastoma has opened up the path for potential targeted therapy in the future. Novel recent advances such as liquid biopsy, prenatal diagnosis, prognostic biomarkers, tylectomy, and chemoplaque point to promising future directions.

Masquerade syndrome: A review of uveitic imposters.

Masquerade syndromes in uveitis are complex clinical conditions where non-inflammatory diseases mimic uveitic manifestations, often leading to diagnostic and therapeutic challenges. This review delves into the diverse spectrum of masquerade syndromes, categorizing them into neoplastic and non-neoplastic entities. We explore the prevalence of primary intraocular lymphoma, leukaemia, retinoblastoma, and other malignancies, as well as conditions like retinitis pigmentosa and endophthalmitis that can present as uveitis. Through detailed analysis of symptoms, diagnostic methods, and treatment approaches, the review emphasizes the importance of considering masquerade syndromes in differential diagnoses to prevent mismanagement. The synthesis of current knowledge aims to enhance clinicians' ability to discern these complex presentations, advocating for a multidisciplinary approach to diagnosis and care, thereby improving patient outcomes in cases of uveitic masquerade syndromes.

Mutation profile of Bardet-Biedl syndrome patients from India: Implicative role of multiallelic rare variants and oligogenic inheritance pattern.

Bardet-Biedl syndrome (BBS), a rare primary form of ciliopathy, with heterogeneous clinical and genetic presentation is characterized by rod cone dystrophy, obesity, polydactyly, urogenital abnormalities, and cognitive impairment. Here, we delineate the genetic profile in a cohort of 108 BBS patients from India by targeted gene sequencing-based approach for a panel of ciliopathy (including BBS) and other inherited retinal disease genes. We report here a higher frequency of BBS10 and BBS1 gene variations. A different spectrum of variations including a putatively novel gene TSPOAP1, for BBS was identified. Increased percentage frequency of digenic variants (36%) in the disease cohort, role of modifiers in familial cases are some of the salient observations in this work. This study appends the knowledge of BBS genetics pertaining to patients from India. We observed a different molecular epidemiology of BBS patients in this study cohort compared to other reports, which emphasizes the need for molecular testing in affected patients.

Next-generation sequencing--based genetic testing and phenotype correlation in retinitis pigmentosa patients from India.

Purpose: Inherited retinal dystrophies (IRD) are a heterogeneous group of retinal diseases leading to progressive loss of photoreceptors through apoptosis. Retinitis pigmentosa (RP) is considered the most common form of IRD. Panel-based testing in RP has proven effective in identifying the causative genetic mutations in 70% and 80% of the patients. This is a retrospective, observational, single-center study of 107 RP patients who had undergone next-generation sequencing-based targeted gene panel testing for IRD genes. These patients were inspected for common phenotypic features to arrive at meaningful genotype-phenotype correlation. Methods: Patients underwent complete ophthalmic examination, and blood was collected from the proband for DNA extraction after documenting the pedigree. Targeted Next Generation Sequencing (NGS) was done by panel-based testing for IRD genes followed by co-segregation analysis wherever applicable. Results: Of the 107 patients, 72 patients had pathogenic mutations. The mean age of onset of symptoms was 14 ± 12 years (range: 5-55). Mean (Best Corrected Visual Acuity) BCVA was 6/48 (0.9 logMAR) (range 0.0-3.0). At presentation, over one-third of eyes had BCVA worse than 6/60 (<1 logMAR). Phenotype analysis with the gene defects showed overlapping features, such as peripheral well-defined chorioretinal atrophic patches in patients with CERKL, PROM1, and RPE65 gene mutations and large macular lesions in patients with RDH12 and CRX gene mutations, respectively. Nummular or clump-like pigmentation was noted in CRB1, TTC8, PDE6A, and PDE6B. Conclusion: NGS-based genetic testing can help clinicians to diagnose RP more accurately, and phenotypic correlations can also help in better patient counselling with respect to prognosis and guidance regarding ongoing newer gene-based therapies.

Retinoblastoma seeds: impact on American Joint Committee on Cancer clinical staging.

AIM: To investigate whether the American Joint Committee on Cancer (AJCC) clinical category cT2b needs to be subclassified by the type and distribution of retinoblastoma (RB) seeding. METHODS: Multicentre, international registry-based data were collected from RB centres enrolled between January 2001 and December 2013. 1054 RB eyes with vitreous or subretinal seeds from 18 ophthalmic oncology centres, in 13 countries within six continents were analysed. Local treatment failure was defined as the use of secondary enucleation or external beam radiation therapy (EBRT) and was estimated with the Kaplan-Meier method. RESULTS: Clinical category cT2b included 1054 eyes. Median age at presentation was 16.0 months. Of these, 428 (40.6%) eyes were salvaged, and 430 (40.8%) were treated with primary and 196 (18.6%) with secondary enucleation. Of the 592 eyes that had complete data for globe salvage analysis, the distribution of seeds was focal in 143 (24.2%) and diffuse in 449 (75.8%). The 5-year Kaplan-Meier cumulative globe-salvage (without EBRT) was 78% and 49% for eyes with focal and diffuse RB seeding, respectively. Cox proportional hazards regression analysis confirmed a higher local treatment failure risk with diffuse seeds as compared with focal seeds (hazard rate: 2.8; p<0.001). There was insufficient evidence to prove or disprove an association between vitreous seed type and local treatment failure risk(p=0.06). CONCLUSION: This international, multicentre, registry-based analysis of RB eyes affirmed that eyes with diffuse intraocular distribution of RB seeds at diagnosis had a higher risk of local treatment failure when compared with focal seeds. Subclassification of AJCC RB category cT2b into focal vs diffuse seeds will improve prognostication for eye salvage.

A case of non-Hodgkin lymphoma diagnosed after 35-month of initial presentation as recurrent vitritis with multiple negative biopsies.

To report a case of non-Hodgkin lymphoma (NHL) that was diagnosed 35-month of initial ocular manifestation. Retrospective chart review. A 53-year-old male presented with painless diminution of vision in both eyes. He subsequently underwent extensive laboratory investigations including multiple vitreous biopsies with a suspicion of intraocular lymphoma. Cytology from the vitreous aspirate failed to diagnose any relevant pathology. After 35-month from the onset of his ocular symptom, a brain biopsy revealed a round cell tumor suggestive of NHL. Even with high index of suspicion, consultation with ocular oncologist, imaging, and diagnostic vitrectomy, the diagnosis of lymphoma remains challenging.

Younger Age and Albuminuria are Associated with Proliferative Diabetic Retinopathy and Diabetic Macular Edema in the South Indian GeNetics of DiAbeTic Retinopathy (SIGNATR) Study.

Purpose: The purpose of the South Indian GeNetics of DiAbeTic Retinopathy (SIGNATR) Study is to identify non-genetic and genetic risk factors associated with diabetic retinopathy (DR). This report examines the non-genetic risk factors for DR in South Indian patients.Methods: Participants with South Indian ancestry and type 2 diabetes (T2D) were included from two sources: the Sankara Nethralaya Diabetic Retinopathy and Molecular Genetics Study (SN-DREAMS) and prospective recruitment at Sankara Nethralaya affiliates. Fundus photography and optical coherence tomography (OCT) were obtained on participants. Fundus images were graded for DR severity and OCTs were graded for center-involved diabetic macular edema (ciDME). Multivariate analyses were performed using stepwise logistic regression to assess effects of the demographic and clinical factors on proliferative DR (PDR) and DME.Results: Among the 2941 participants with DR grading, participants with PDR were more likely to be younger [odds ratio (OR)=0.95], men (OR = 1.83), have a longer duration of diabetes (OR = 1.10), have a higher hemoglobin A1c (OR = 1.12), have albuminuria (OR = 5.83), have hypertension (OR = 1.69), have a higher HDL (OR = 1.02) and a lower total cholesterol (OR = 0.99) (all p < 0.05). Among the 483 participants with gradable OCT scans, participants who had ciDME were more likely to be younger (OR = 0.97), men (OR = 2.80), have a longer duration of diabetes (OR = 1.06), have lower triglycerides (OR = 0.99), and have albuminuria (OR = 3.12) (all p < 0.05).Conclusions: Younger age, male sex, longer duration of diabetes, higher HbA1c, and presence of albuminuria were identified as risk factors for PDR and DME in a South Indian population with T2D.

Metastatic Death Based on Presenting Features and Treatment for Advanced Intraocular Retinoblastoma: A Multicenter Registry-Based Study.

PURPOSE: To evaluate presenting features, tumor size, and treatment methods for risk of metastatic death due to advanced intraocular retinoblastoma (RB). DESIGN: International, multicenter, registry-based retrospective case series. PARTICIPANTS: A total of 1841 patients with advanced RB. METHODS: Advanced RB was defined by 8th edition American Joint Committee on Cancer (AJCC) categories cT2 and cT3 and new AJCC-Ophthalmic Oncology Task Force (OOTF) Size Groups (1: < 50% of globe volume, 2: > 50% but < 2/3, 3: > 2/3, and 4: diffuse infiltrating RB). Treatments were primary enucleation, systemic chemotherapy with secondary enucleation, and systemic chemotherapy with eye salvage. MAIN OUTCOME MEASURES: Metastatic death. RESULTS: The 5-year Kaplan-Meier cumulative survival estimates by patient-level AJCC clinical subcategories were 98% for cT2a, 96% for cT2b, 88% for cT3a, 95% for cT3b, 92% for cT3c, 84% for cT3d, and 75% for cT3e RB. Survival estimates by treatment modality were 96% for primary enucleation, 89% for systemic chemotherapy and secondary enucleation, and 90% for systemic chemotherapy with eye salvage. Risk of metastatic mortality increased with increasing cT subcategory (P < 0.001). Cox proportional hazards regression analysis confirmed a higher risk of metastatic mortality in categories cT3c (glaucoma, hazard ratio [HR], 4.9; P = 0.011), cT3d (intraocular hemorrhage, HR, 14.0; P < 0.001), and cT3e (orbital cellulitis, HR, 19.6; P < 0.001) than in category cT2a and with systemic chemotherapy with secondary enucleation (HR, 3.3; P < 0.001) and eye salvage (HR, 4.9; P < 0.001) than with primary enucleation. The 5-year Kaplan-Meier cumulative survival estimates by AJCC-OOTF Size Groups 1 to 4 were 99%, 96%, 94%, and 83%, respectively. Mortality from metastatic RB increased with increasing Size Group (P < 0.001). Cox proportional hazards regression analysis revealed that patients with Size Group 3 (HR, 10.0; P = 0.002) and 4 (HR, 41.1; P < 0.001) had a greater risk of metastatic mortality than Size Group 1. CONCLUSIONS: The AJCC-RB cT2 and cT3 subcategories and size-based AJCC-OOTF Groups 3 (> 2/3 globe volume) and 4 (diffuse infiltrating RB) provided a robust stratification of clinical risk for metastatic death in advanced intraocular RB. Primary enucleation offered the highest survival rates for patients with advanced intraocular RB.

Retinoblastoma patient-derived stem cells-an in vivo model to study the role of RB1 in adipogenesis.

Retinoblastoma (RB1) protein is a multifunctional protein that plays an important role in cell cycle regulation and cell differentiation, including adipogenesis. A detailed literature search to understand the role of RB1 in adipogenesis revealed that the nature of the RB1 inactivation (in vivo/in vitro) led to differences in adipogenesis. The majority of these studies were animal-based, and the only study in humans employed an in vitro mode of RB1 inactivation. To overcome these differences and lack of human studies, we sought to explore the role of RB1 in adipogenesis using orbital adipose mesenchymal stem cells (OAMSCs) from patients with retinoblastoma that innately carry a heterozygous RB1 mutation. We hypothesized that these patient-derived RB1 mutant OAMSCs can model in vivo RB1 inactivation in humans. Our study revealed increased adipogenesis with a bias toward brown adipogenesis in the RB1 mutant in addition to an increased number of adipocytes in the mitotic phase.

High-risk Pathologic Features Based on Presenting Findings in Advanced Intraocular Retinoblastoma: A Multicenter, International Data-Sharing American Joint Committee on Cancer Study.

PURPOSE: To determine the value of clinical features for advanced intraocular retinoblastoma as defined by the eighth edition of the American Joint Committee on Cancer (AJCC) cT3 category and AJCC Ophthalmic Oncology Task Force (OOTF) Size Groups to predict the high-risk pathologic features. DESIGN: International, multicenter, registry-based retrospective case series. PARTICIPANTS: Eighteen ophthalmic oncology centers from 13 countries over 6 continents shared evaluations of 942 eyes enucleated as primary treatment for AJCC cT3 and, for comparison, cT2 retinoblastoma. METHODS: International, multicenter, registry-based data were pooled from patients enrolled between 2001 and 2013. High-risk pathologic features were defined as AJCC categories pT3 and pT4. In addition, AJCC OOTF Size Groups were defined as follows: (1) less than half, (2) more than half but less than two thirds, (3) more than two thirds of globe volume involved, and (4) diffuse infiltrating retinoblastoma. MAIN OUTCOME MEASURES: Statistical risk of high-risk pathologic features corresponding to AJCC cT3 subcategories and AJCC OOTF Size Groups. RESULTS: Of 942 retinoblastoma eyes treated by primary enucleation, 282 (30%) showed high-risk pathologic features. Both cT subcategories and AJCC OOTF Size Groups (P < 0.001 for both) were associated with high-risk pathologic features. On logistic regression analysis, cT3c (iris neovascularization with glaucoma), cT3d (intraocular hemorrhage), and cT3e (aseptic orbital cellulitis) were predictive factors for high-risk pathologic features when compared with cT2a with an odds ratio of 2.3 (P = 0.002), 2.5 (P = 0.002), and 3.3 (P = 0.019), respectively. Size Group 3 (more than two-thirds globe volume) and 4 (diffuse infiltrative retinoblastoma) were the best predictive factors with an odds ratio of 3.3 and 4.1 (P < 0.001 for both), respectively, for high-risk pathologic features when compared with Size Groups 1 (i.e., < 50% of globe volume). CONCLUSIONS: The AJCC retinoblastoma staging clinical cT3c-e subcategories (glaucoma, intraocular hemorrhage, and aseptic orbital cellulitis, respectively) as well as the AJCC OOTF Size Groups 3 (tumor more than two thirds of globe volume) and 4 (diffuse infiltrative retinoblastoma) both allowed stratification of clinical risk factors that can be used to predict the presence of high-risk pathologic features and thus facilitate treatment decisions.

Clinical explainable differential diagnosis of polypoidal choroidal vasculopathy and age-related macular degeneration using deep learning.

BACKGROUND: This study aims to achieve an automatic differential diagnosis between two types of retinal pathologies with similar pathological features - Polypoidal choroidal vasculopathy (PCV) and wet age-related macular degeneration (AMD) from volumetric optical coherence tomography (OCT) images, and identify clinically-relevant pathological features, using an explainable deep-learning-based framework. METHODS: This is a retrospective study with data from a cross-sectional cohort. The OCT volume of 73 eyes from 59 patients was included in this study. Disease differentiation was achieved through single-B-scan-based classification followed by a volumetric probability prediction aggregation step. We compared different labeling strategies with and without identifying pathological B-scans within each OCT volume. Clinical interpretability was achieved through normalized aggregation of B-scan-based saliency maps followed by maximum-intensity-projection onto the en face plane. We derived the PCV score from the proposed differential diagnosis framework with different labeling strategies. The en face projection of saliency map was validated with the pathologies identified in Indocyanine green angiography (ICGA). RESULTS: Model trained with both labeling strategies achieved similar level differentiation power (>90%), with good correspondence between pathological features detected from the projected en face saliency map and ICGA. CONCLUSIONS: This study demonstrated the potential clinical application of non-invasive differential diagnosis using AI-driven OCT-based analysis, with minimal requirement of labeling efforts, along with clinical explainability achieved through automatically detected disease-related pathologies.

Sex, gender, and retinoblastoma: analysis of 4351 patients from 153 countries.

OBJECTIVE: To investigate in a large global sample of patients with retinoblastoma whether sex predilection exists for this childhood eye cancer. METHODS: A cross-sectional analysis including 4351 treatment-naive retinoblastoma patients from 153 countries who presented to 278 treatment centers across the world in 2017. The sex ratio (male/female) in the sample was compared to the sex ratio at birth by means of a two-sided proportions test at global level, country economic grouping, continent, and for selected countries. RESULTS: For the entire sample, the mean retinoblastoma sex ratio, 1.20, was higher than the weighted global sex ratio at birth, 1.07 (p < 0.001). Analysis at economic grouping, continent, and country-level demonstrated differences in the sex ratio in the sample compared to the ratio at birth in lower-middle-income countries (n = 1940), 1.23 vs. 1.07 (p = 0.019); Asia (n = 2276), 1.28 vs. 1.06 (p < 0.001); and India (n = 558), 1.52 vs. 1.11 (p = 0.008). Sensitivity analysis, excluding data from India, showed that differences remained significant for the remaining sample (χ2 = 6.925, corrected p = 0.025) and for Asia (χ2 = 5.084, corrected p = 0.036). Excluding data from Asia, differences for the remaining sample were nonsignificant (χ2 = 2.205, p = 0.14). CONCLUSIONS: No proof of sex predilection in retinoblastoma was found in the present study, which is estimated to include over half of new retinoblastoma patients worldwide in 2017. A high male to female ratio in Asian countries, India in specific, which may have had an impact on global-level analysis, is likely due to gender discrimination in access to care in these countries, rather than a biological difference between sexes.

Ocular Co-infection with Mycobacterium Tuberculosis and Toxoplasma Gondii in an Immunocompetent Patient - A Case Report.

PURPOSE: To report a case of ocular co-infection with Mycobacterium tuberculosis and Toxoplasma gondii in an immunocompetent woman. METHOD: Retrospective observational case report. RESULT: A 61-year-old woman presented with decreased vision and floaters in the right eye of 1-month duration. Ocular examination revealed panuveitis with a large yellowish-white retinochoroiditis lesion adjacent to a chorioretinal scar. Investigations showed positive Mantoux test, QuantiFERON TB test, and HRCT chest suggestive of active pulmonary tuberculosis. Serology revealed raised IgG anti T. gondii antibody. Vitreous aspirate was positive for M. tuberculosis and T. gondii genome by polymerase chain reaction and showed high IgG and IgM T. gondii antibodies. She was treated with anti toxoplasmic and antitubercular therapy along with oral corticosteroid and therapeutic vitrectomy. CONCLUSION: Ocular tuberculosis and toxoplasmosis can not only mimic each other but also present as co-infection in rare cases.

Chronic myelogenous leukemia in a child following treatment for bilateral retinoblastoma.

A 3-year-old child was incidentally found to have chronic myelogenous leukemia (CML) during an admission for a routine ophthalmic examination under anesthesia. The child had received systemic chemotherapy and focal treatment for Groups C and D retinoblastoma in the right and left eye, respectively, when she was 7 months old. CML was treated with dasatinib, and the child attained a major molecular response. The child is now 3 years after treatment of CML, and the retinoblastoma remains inactive. CML following treatment of retinoblastoma is a rare occurrence. Long term and close monitoring of retinoblastoma patients who received systemic chemotherapy using serial blood tests is essential.

Global Retinoblastoma Treatment Outcomes: Association with National Income Level.

PURPOSE: To compare metastasis-related mortality, local treatment failure, and globe salvage after retinoblastoma in countries with different national income levels. DESIGN: International, multicenter, registry-based retrospective case series. PARTICIPANTS: Two thousand one hundred ninety patients, 18 ophthalmic oncology centers, and 13 countries on 6 continents. METHODS: Multicenter registry-based data were pooled from retinoblastoma patients enrolled between January 2001 and December 2013. Adequate data to allow American Joint Committee on Cancer staging, eighth edition, and analysis for the main outcome measures were available for 2085 patients. Each country was classified by national income level, as defined by the 2017 United Nations World Population Prospects, and included high-income countries (HICs), upper middle-income countries (UMICs), and lower middle-income countries (LMICs). Patient survival was estimated with the Kaplan-Meier method. Logistic and Cox proportional hazards regression models were used to determine associations between national income and treatment outcomes. MAIN OUTCOME MEASURES: Metastasis-related mortality and local treatment failure (defined as use of secondary enucleation or external beam radiation therapy). RESULTS: Most (60%) study patients resided in UMICs and LMICs. The global median age at diagnosis was 17.0 months and higher in UMICs (20.0 months) and LMICs (20.0 months) than HICs (14.0 months; P < 0.001). Patients in UMICs and LMICs reported higher rates of disease-specific metastasis-related mortality and local treatment failure. As compared with HICs, metastasis-related mortality was 10.3-fold higher for UMICs and 9.3-fold higher for LMICs, and the risk for local treatment failure was 2.2-fold and 1.6-fold higher, respectively (all P < 0.001). CONCLUSIONS: This international, multicenter, registry-based analysis of retinoblastoma management revealed that lower national income levels were associated with significantly higher rates of metastasis-related mortality, local treatment failure, and lower globe salvage.

Correction to: EpCAM aptamer mediated cancer cell specific delivery of EpCAM siRNA using polymeric nanocomplex.

An amendment to this paper has been published and can be accessed via the original article.