Epithelioid hemangioendothelioma in children: The European Pediatric Soft Tissue Sarcoma Study Group experience.

The European pediatric Soft tissue sarcoma Study Group analyzed all children with epithelioid hemangioendothelioma prospectively registered in the NRSTS-05 (EUDRACT 2005-001139-31) and in MTS-2008 (NCT00379457) studies: 10 patients with localized and one with metastatic disease. Median age was 14.3 years (range, 9.0-18.8). Local therapy was initial primary surgery in seven cases, and five patients received systemic therapy. No patients received radiotherapy. After a median follow-up of 50 months (range, 6-176) for living patients, nine patients remain alive off therapy and two died. Five-year progression free and overall survivals are, respectively, 77.1% (95% confidence interval [CI]: 34.5-93.9) and 74.1% (95% CI: 28.1-93.0).

Epigenetic footprint enables molecular risk stratification of hepatoblastoma with clinical implications.

BACKGROUND & AIMS: Hepatoblastoma (HB) is a rare disease. Nevertheless, it is the predominant pediatric liver cancer, with limited therapeutic options for patients with aggressive tumors. Herein, we aimed to uncover the mechanisms of HB pathobiology and to identify new biomarkers and therapeutic targets in a move towards precision medicine for patients with advanced HB. METHODS: We performed a comprehensive genomic, transcriptomic and epigenomic characterization of 159 clinically annotated samples from 113 patients with HB, using high-throughput technologies. RESULTS: We discovered a widespread epigenetic footprint of HB that includes hyperediting of the tumor suppressor BLCAP concomitant with a genome-wide dysregulation of RNA editing and the overexpression of mainly non-coding genes of the oncogenic 14q32 DLK1-DIO3 locus. By unsupervised analysis, we identified 2 epigenomic clusters (Epi-CA, Epi-CB) with distinct degrees of DNA hypomethylation and CpG island hypermethylation that are associated with the C1/C2/C2B transcriptomic subtypes. Based on these findings, we defined the first molecular risk stratification of HB (MRS-HB), which encompasses 3 main prognostic categories and improves the current clinical risk stratification approach. The MRS-3 category (28%), defined by strong 14q32 locus expression and Epi-CB methylation features, was characterized by CTNNB1 and NFE2L2 mutations, a progenitor-like phenotype and clinical aggressiveness. Finally, we identified choline kinase alpha as a promising therapeutic target for intermediate and high-risk HBs, as its inhibition in HB cell lines and patient-derived xenografts strongly abrogated tumor growth. CONCLUSIONS: These findings provide a detailed insight into the molecular features of HB and could be used to improve current clinical stratification approaches and to develop treatments for patients with HB. LAY SUMMARY: Hepatoblastoma is a rare childhood liver cancer that has been understudied. We have used cutting-edge technologies to expand our molecular knowledge of this cancer. Our biological findings can be used to improve clinical management and pave the way for the development of novel therapies for this cancer.

Surgical management of Wilms tumor with intravascular extension: a single-institution experience.

The purpose of this study was to retrospectively analyze the clinical presentation, treatment, and outcomes of children with Wilms tumor (WT) and intravascular extension who were treated at a single institution. A retrospective review was conducted of medical records of all children with Wilms tumor and intravascular extension treated at Virgen del Rocio Children's Hospital between 1992 and 2010. Seven patients (median age 3.4 years, range 2-8.1 years) were identified. At diagnosis, 6 of the 7 patients (85.7%) presented with tumor thrombus that reached the right atrium (RA) and 1 patient with infrahepatic inferior vena cava (IVC) thrombus. All patients received neoadjuvant chemotherapy (SIOP 2001 protocol) with vincristine, doxorubicin, and actinomycin D. Regression of the intravascular extension of the tumor was documented in all patients. Postchemotherapy level of extension was suprahepatic IVC in 1 patient, infrahepatic IVC in 2 patients, renal vein (RV) in 1 patient, and RA in 3 patients. Nephrectomy and thrombectomy were performed in all cases, requiring cardiopulmonary bypass for the 4 patients who presented with suprahepatic IVC and RA thrombus. The other 3 patients with infrahepatic IVC and RV involvement underwent cavotomy and thrombus extraction. Computed tomography, ultrasonography, and echocardiography were used for diagnosis and follow-up. All patients remain disease-free with a median follow-up of 6.3 years (range, 2-19 years). Neoadjuvant chemotherapy for WT with intravascular extension may facilitate the resection by decreasing the extent of the tumor thrombus. Cardiopulmonary bypass is indicated for suprahepatic IVC and RA involvement. Accurate diagnostic imaging is necessary.

Role of radiation therapy in the multidisciplinary management of Ewing's Sarcoma of bone in pediatric patients: An effective treatment for local control.

BACKGROUND: Radiotherapy (RT) plays an important role in the multidisciplinary management of Ewing's Sarcoma (ES), especially in unresectable cases. AIM: Assessment of efficacy of RT in terms of local control in pediatric patients with primary ES of bone. MATERIALS AND METHODS: Thirty-six patients younger than 17 years old with ES treated with combined RT and chemotherapy with (N = 14) or without (N = 22) prior surgery from 1981 to 2008 were retrospectively reviewed. Since 1995, they were all treated according to the Spanish Society of Pediatric Oncology protocol (55.5% cases). Those patients received vincristine, ifosfamide, doxorubicin and etoposide. The TNM classification was as follows: 17 T1, 18 T2 and 1 T3; 36 N0; 29 M0, 5 M1a and 2 M1b. Analysis was stratified by treatment: definitive RT or pre/postoperative RT. RESULTS: The 36 patients (21 male; 15 female) had a median age of 10 years (range 2-17 years). Median follow-up of living patients was 105 months. The 2-year local control (LC) rate for all patients was 88%. Five-year LC rates for patients treated with definitive and pre/postoperative RT were 91% and 86%, respectively. Two-year overall survival and disease-free survival rates for all patients were 68% and 66%, respectively. Low phosphatase alkaline levels and local and distant recurrences were significantly predictive of worse prognosis (P = 0.021, P = 0.011, P = 0.007, respectively). CONCLUSION: Radiotherapy with and without surgery is a highly effective local treatment option in the multidisciplinary management of ES in pediatric patients.

Myeloablative therapy against high risk Ewing's sarcoma: A single institution experience and literature review.

BACKGROUND: Attempts to improve survival outcomes of patients with high risk Ewing's sarcoma (ES) have focused on chemotherapy dose intensification strategies. AIM: The objective of this study is to retrospectively evaluate clinical characteristics and outcome of pediatric patients with high risk ES treated at a single institution. MATERIALS AND METHODS: From 1995 to 2008, seventeen patients (male:female, 14:3) were treated with dose-intensive therapy in our institution. Median age at diagnosis was 10 years (range: 2-15). Seven patients had metastases at diagnosis (lung in 6 cases and bone in one case). Eleven patients presented with unresectable disease. Fifteen (88.2%) received the Spanish Society of Pediatric Oncology protocol which includes six cycles of vincristine, doxorubicin, ifosfamide and etoposide. Two out of the six cases that were resectable received postoperative radiation. In addition, eleven patients received definitive radiation therapy. Finally, twelve (70.5%) out of 17 patients received myeloablative therapy with melphalan/etoposide. The rest of patients (N = 5) received busulfan/melphalan. RESULTS: Median follow-up was 78 months (range: 15-155 months). Initial responses were complete in all patients, but 9 of them developed progression disease. Seven patients became long-term event-free survivors. No patient died of toxicity after transplantation. The 2- and 5-year overall survival rates for all patients were 93% and 73%, respectively. Event-free survival rates were 74% and 54% at 2 and 5 years, respectively. CONCLUSION: This single-institution experience suggests that myeloablative therapy against high risk ES is effective and safe.

Initial experience involving treatment and retreatment with carmustine wafers in combination with oral temozolomide: long-term survival in a child with relapsed glioblastoma multiforme.

BACKGROUND: Glioblastomas occur infrequently in children, and the prognosis is better than for glioblastomas seen in adults. Aggressive treatment is justified in pediatric patients. OBSERVATIONS: We present the case of a 6-year-old child with malignant posterior temporal glioma treated with surgery, radiotherapy, local chemotherapy with carmustine wafers, and oral therapy with temozolomide, both at initial diagnosis and at relapse 18 months later. After 6 years, the patient seems healthy with no focal neurologic signs, and imaging studies show no evidence of disease. CONCLUSION: Multimodal therapy was found to have a very positive outcome for a child with malignant glioma.

Vincristine-ticlopidine-aspirin: an effective therapy in children with Kasabach-Merritt phenomenon associated with vascular tumors.

Kasabach-Merritt phenomenon (KMP) is a serious coagulopathy with severe thrombocytopenia (<10,000/mm³) that occurs in the presence of an enlarging vascular tumor such as kaposiform hemangioendothelioma (KHE) and tufted angioma (TA). The natural history and treatment of these lesions remain controversial. The authors report a KHE case and a TA case that presented with KMP, describing their successful pharmacological management with vincristine, ticlopidine, and aspirin.

CD44-high neural crest stem-like cells are associated with tumour aggressiveness and poor survival in neuroblastoma tumours.

BACKGROUND: Neuroblastoma is a paediatric tumour originated from sympathoadrenal precursors and characterized by its heterogeneity and poor outcome in advanced stages. Intra-tumoral cellular heterogeneity has emerged as an important feature in neuroblastoma, with a potential major impact on tumour aggressiveness and response to therapy. CD44 is an adhesion protein involved in tumour progression, metastasis and stemness in different cancers; however, there has been controversies about the significance of CD44 expression in neuroblastoma and its relationship with tumour progression. METHODS: We have performed transcriptomic analysis on patient tumour samples studying the outcome of patients with high CD44 expression. Adhesion, invasion and proliferation assays were performed in sorted CD44high neuroblastoma cells. Tumoursphere cultures have been used to enrich in undifferentiated stem-like cells and to asses self-renewal and differentiation potential. We have finally performed in vivo tumorigenic assays on cell line-derived or Patient-derived xenografts. FINDINGS: We show that high CD44 expression is associated with low survival in high-grade human neuroblastoma, independently of MYCN amplification. CD44 is expressed in a cell population with neural crest stem-like features, and with the capacity to generate multipotent, undifferentiated tumourspheres in culture. These cells are more invasive and proliferative in vitro. CD44 positive cells obtained from tumours are more tumorigenic and metastatic, giving rise to aggressive neuroblastic tumours at high frequency upon transplantation. INTERPRETATION: We describe an unexpected intra-tumoural heterogeneity within cellular entities expressing CD44 in neuroblastoma, and propose that CD44 has a role in neural crest stem-like undifferentiated cells, which can contribute to tumorigenesis and malignancy in this type of cancer. FUNDING: Research supported by grants from the "Asociación Española contra el Cáncer" (AECC), the Spanish Ministry of Science and Innovation SAF program (SAF2016-80412-P), and the European Research Council (ERC Starting Grant to RP).

Neural crest derived progenitor cells contribute to tumor stroma and aggressiveness in stage 4/M neuroblastoma.

Pediatric tumors arise upon oncogenic transformation of stem/progenitor cells during embryonic development. Given this scenario, the existence of non-tumorigenic stem cells included within the aberrant tumoral niche, with a potential role in tumor biology, is an intriguing and unstudied possibility. Here, we describe the presence and function of non-tumorigenic neural crest-derived progenitor cells in aggressive neuroblastoma (NB) tumors. These cells differentiate into neural crest typical mesectodermal derivatives, giving rise to tumor stroma and promoting proliferation and tumor aggressiveness. Furthermore, an analysis of gene expression profiles in stage 4/M NB revealed a neural crest stem cell (NCSC) gene signature that was associated to stromal phenotype and high probability of relapse. Thus, this NCSC gene expression signature could be used in prognosis to improve stratification of stage 4/M NB tumors. Our results might facilitate the design of new therapies by targeting NCSCs and their contribution to tumor stroma.

[Early clinical trials in paediatric oncology in Spain: a nationwide perspective]. / Ensayos clínicos precoces en oncología pediátrica en España: una perspectiva nacional.

INTRODUCTION: Cancer is the leading cause of death between the first year of life and adolescence, and some types of diseases are still a major challenge in terms of cure. There is, therefore, a major need for new drugs. Recent findings in cancer biology open the door to the development of targeted therapies against individual molecular changes, as well as immunotherapy. Promising results in adult anti-cancer drug development have not yet been translated into paediatric clinical practice. A report is presented on the activity in early paediatric oncology trials (phase I-II) in Spain. MATERIAL AND METHODS: All members of the Spanish Society of Paediatric Haematology Oncology (SEHOP) were contacted in order to identify early clinical trials in paediatric cancer opened between 2005 and 2015. RESULTS: A total of 30 trials had been opened in this period: 21 (70%) in solid tumours, and 9 (30%) in malignant haemopathies. A total of 212 patients have been enrolled. The majority was industry sponsored (53%). Since 2010, four centres have joined the international consortium of Innovative Therapies for Children with Cancer (ITCC), which has as its aim to develop novel therapies for paediatric tumours. A significant number of new studies have opened since 2010, improving the treatment opportunities for our children. Results of recently closed trials show the contribution of Spanish investigators, the introduction of molecularly targeted agents, and their benefits. CONCLUSIONS: The activity in clinical trials has increased in the years analysed. The SEHOP is committed to develop and participate in collaborative academic trials, in order to help in the advancement and optimisation of existing therapies in paediatric cancer.

Diffuse unilateral subacute neuroretinitis in Venezuela.

PURPOSE: To describe the clinical features and management of the largest reported series to date of patients with diffuse unilateral subacute neuroretinitis (DUSN). DESIGN: Observational case series. METHODS: The charts of all patients coded as having DUSN in a vitreoretinal clinic in Caracas, Venezuela between July 1979 and August 2000 were retrospectively reviewed. MAIN OUTCOME MEASURES: Demographic information, presenting visual acuity, clinical course, and treatment were evaluated. RESULTS: We identified 82 eyes of 78 patients with DUSN. The mean age at diagnosis was 16.7 years, significantly younger than the mean age of the Venezuelan population. Sixty-five (83.3%) patients were 20 years old or younger (P<0.001 when compared with the population of Venezuela). Thirty-three (42.3%) of the patients were female. The presenting visual acuity was 20/400 or worse in 69 eyes (84.1%). The subretinal nematode was identified in 33 eyes (40.2%). All nematodes were small, approximately 400 microm in length. CONCLUSIONS: In Venezuela, DUSN is seen primarily in young patients without a significant gender predilection. The vast majority of patients in this population presented with severe vision loss that was irreversible.

Prevalence and risk factors for proliferative vitreoretinopathy in eyes with rhegmatogenous retinal detachment but no previous vitreoretinal surgery.

PURPOSE: To determine the prevalence of and risk factors for proliferatative vitreoretinopathy (PVR) in eyes with rhegmatogenous retinal detachment but no previous vitreoretinal surgery. DESIGN: Observational case series. METHODS: Prospective study. SETTING: A private vitreoretinal clinic in Caracas, Venezuela. STUDY POPULATION: 119 eyes of 119 patients who presented with rhegmatogenous retinal detachment but no previous vitreoretinal surgery between 1995 and 1998. OBSERVATION PROCEDURES: Data from detailed preoperative and postoperative examinations of each eye were recorded prospectively and entered into an electronic database. MAIN OUTCOME MEASURES: Prevalence of PVR of any type and severe PVR, preoperative risk factors for PVR of any type and severe PVR, effect of PVR and retinal detachment duration on initial and final visual acuity, and surgical complexity. RESULTS: The prevalence of PVR of any type was 52.9% and of severe PVR was 26.9%. The mean retinal detachment duration (+/-SD) was 58.4 (+/-129.1) days, and the mean time from initial examination to surgical treatment (+/-SD) was 24.3 (81.2) days. By univariable analysis, long retinal detachment duration, poor initial visual acuity, and large retinal detachment extent were significantly associated with PVR prevalence and severity. The presence of vitreous hemorrhage was significantly associated with PVR prevalence, and cataract was significantly associated with PVR severity. By multivariable analysis, long retinal detachment duration and large retinal detachment extent were simultaneous risk factors for PVR prevalence, while long retinal detachment, large retinal detachment extent, and poor initial visual acuity were simultaneous risk factors for PVR severity. Eyes with longer retinal detachment duration, PVR of any type, and severe PVR had worse initial and final visual acuities than eyes with shorter retinal detachment duration or those without PVR, respectively. Eyes with PVR had more complex surgery than those without PVR. CONCLUSIONS: PVR occurred very frequently in this population and was associated with more complex surgery and worse visual outcomes than among eyes without PVR. We have identified preventable risk factors associated with PVR that suggest a specific and significant need for better access to ophthalmologic care and patient education in this group of patients.

Retinal detachment in myopic eyes after laser in situ keratomileusis.

PURPOSE: To report the characteristics and surgical outcomes of rhegmatogenous retinal detachments in myopic eyes after laser in situ keratomileusis (LASIK). METHODS: Clinical charts of patients that developed rhegmatogenous retinal detachment after LASIK were reviewed. Surgery to repair rhegmatogenous retinal detachment was performed in 31 eyes (mean follow-up of 14 months after vitreoretinal surgery). RESULTS: A total of 38,823 eyes underwent surgical correction of myopia from -0.75 to -29.00 D (mean -6.00 D). Thirty-three eyes (27 patients; frequency .08%) developed rhegmatogenous retinal detachment after LASIK; detachments occurred between 12 days and 60 months (mean 16.3 mo) after LASIK. Eyes that developed a rhegmatogenous retinal detachment had a mean -8.75 D before LASIK. Most rhegmatogenous retinal detachment and retinal breaks occurred in the temporal quadrants (71.1%). Final best spectacle-corrected visual acuity (BSCVA) of 20/40 or better was obtained in 38.7% of the 31 eyes (two patients refused surgery). Poor final visual acuity (20/200 or worse) occurred in 22.6% of eyes. Information regarding visual acuity after LASIK and before the development of rhegmatogenous retinal detachment was available in 24 eyes; 45.8% (11/24 eyes) lost two or more lines of visual acuity after vitreo-retinal surgery. Reasons for poor visual acuity included the development of proliferative vitreo-retinopathy (n=5), epiretinal membrane (n=1), chronicity of rhegmatogenous retinal detachment (n=1), new breaks (n=1), displaced corneal flap (n=1), and cataract. CONCLUSIONS: Rhegmatogenous retinal detachment after LASIK for myopia is a serious complication. Final visual acuity may be limited by myopic degeneration, amblyopia, or delayed surgical repair.

Ensayos clínicos precoces en oncología pediátrica en España: una perspectiva nacional / Early clinical trials in paediatric oncology in Spain: a nationwide perspective

Introducción: El cáncer es la primera causa de muerte por enfermedad entre el primer año de vida y la adolescencia. Algunos tipos de enfermedad siguen constituyendo un reto en términos de curación. Existe por tanto una necesidad imperiosa de nuevos fármacos. Algunos descubrimientos recientes en la biología del cáncer abren la puerta al desarrollo de terapias dirigidas contra alteraciones moleculares concretas e inmunoterapia. Esto se ha traducido en resultados prometedores sobre todo en oncología de adultos, y en menor medida todavía en niños. Presentamos la actividad en ensayos clínicos precoces (fase I-II) en oncología pediátrica en España. Material y métodos: A través de la Sociedad Española de Oncología y Hematología Pediátrica (SEHOP) contactamos a sus miembros para identificar los ensayos fase I-II en cáncer pediátrico abiertos entre 2005 y 2015. Resultados: En este periodo se abrieron 30 ensayos: 21 (70%) en tumores sólidos y 9 (30%) en hemopatías malignas y se incluyó a 212 pacientes. La mayoría están promovidos por la industria farmacéutica (53%). Desde 2010, 4 centros se han integrado en el consorcio internacional ITCC cuyo objetivo es desarrollar nuevas terapias en cáncer infantil. Esto ha permitido ampliar el abanico de posibilidades terapéuticas. Los resultados de ensayos clínicos terminados muestran la contribución de los investigadores españoles, la introducción de terapias dirigidas y sus beneficios. Conclusiones: La actividad en ensayos clínicos precoces ha aumentado en estos años. La SEHOP está comprometida a desarrollar y participar en ensayos clínicos académicos colaborativos, que favorezcan el avance en las terapias frente al cáncer infantil (AU)

Introduction: Cancer is the leading cause of death between the first year of life and adolescence, and some types of diseases are still a major challenge in terms of cure. There is, therefore, a major need for new drugs. Recent findings in cancer biology open the door to the development of targeted therapies against individual molecular changes, as well as immunotherapy. Promising results in adult anti-cancer drug development have not yet been translated into paediatric clinical practice. A report is presented on the activity in early paediatric oncology trials (phase I-II) in Spain. Material and methods: All members of the Spanish Society of Paediatric Haematology Oncology (SEHOP) were contacted in order to identify early clinical trials in paediatric cancer opened between 2005 and 2015. Results: A total of 30 trials had been opened in this period: 21 (70%) in solid tumours, and 9 (30%) in malignant haemopathies. A total of 212 patients have been enrolled. The majority was industry sponsored (53%). Since 2010, four centres have joined the international consortium of Innovative Therapies for Children with Cancer (ITCC), which has as its aim to develop novel therapies for paediatric tumours. A significant number of new studies have opened since 2010, improving the treatment opportunities for our children. Results of recently closed trials show the contribution of Spanish investigators, the introduction of molecularly targeted agents, and their benefits. Conclusions: The activity in clinical trials has increased in the years analysed. The SEHOP is committed to develop and participate in collaborative academic trials, in order to help in the advancement and optimisation of existing therapies in paediatric cancer (AU)

Surgical treatment of ocular toxocariasis: anatomic and functional results in 45 patients.

PURPOSE: To evaluate the anatomic and functional outcome after surgery in patients with complicated ocular toxocariasis. METHODS: A retrospective review of the medical records of pediatric patients who underwent a surgical procedure for ocular toxocariasis from July 1990 to January 2005. Patients with postoperative follow-up shorter than 6 months were excluded from the study. Best-corrected visual acuity (BCVA) was arbitrarily divided into 5 groups: 1) no light perception (NLP); 2) light perception (LP) and hand motion (HM); 3) finger counting (FC) to 20/400; 4) 20/300 to 20/60; and 5) 20/50 to 20/20. RESULTS: Forty-five patients with a mean age of 8.1 years (range 6-10) were included in the study. The ocular toxocariasis presentation most commonly encountered was peripheral granuloma (38%). Twenty-one eyes presented with BCVA in the LP/HM group, 18 (40%) eyes in the FC to 20/400 group, 5 (12%) eyes in the 20/300 to 20/60 group, and 1 (5%) eye in the 20/50 to 20/20 group. The most common surgical procedure was pars plana vitrectomy (PPV) in 58% of the eyes. Four eyes (9%) presented with postoperative BCVA of NLP, 2 eyes (4%) in the LP/HM group, 12 eyes (27%) in the FC to 20/400 group, 19 eyes (42%) in the 20/300 to 20/60 group, and 8 eyes (18%) in the 20/50 to 20/20 group. CONCLUSIONS: Surgical treatment of severe ocular complications secondary to toxocara infections results in satisfactory anatomic results and may improve the overall visual outcome of these patients.

Ocular parasitic diseases: a review on toxocariasis and diffuse unilateral subacute neuroretinitis.

Parasitic infections may damage various ocular tissues, thereby causing visual dysfunction. In 1950, Wilder described the first case in which larval forms of nematodal intestinal roundworms (Ascaridoidea: Ascaris, Toxocara, Ancylostoma, Necator, and Strongyloides) were implicated as a cause of intraocular disease. This review focuses on two disorders associated with parasitic infections: ocular toxocariasis and diffuse unilateral subacute neuroretinitis.

Intravitreous bevacizumab injection: an experimental study in New Zealand white rabbits.

OBJECTIVES: To determine the effects of intraocular pressure (IOP) and needle diameter on the amount of reflux after intravitreous bevacizumab injection. METHODS: Prospective randomized interventional study. Twelve New Zealand white rabbits weighing approximately 2.5 to 3.5 kg each were randomized 1:1 to group 1 or group 2. Bevacizumab stained with trypan blue was used for intravitreous injection. To lower the IOP, eyes in group 2 underwent anterior chamber paracentesis before intravitreous injection. Two eyes in each group were injected using 27-, 30-, or 32-gauge needles. If a subconjunctival bleb formed after intravitreous injection, its diameter was measured using a caliper. RESULTS: The median IOP in group 1 was 17.5 mm Hg. Eyes injected using 27-gauge and 30-gauge needles showed stained subconjunctival blebs with median sizes of 3 mm and 1.7 mm, respectively; eyes injected using 32-gauge needles showed no subconjunctival bleb formation. The median IOP in group 2 was 10.3 mm Hg. Eyes injected using 27-gauge needles showed stained subconjunctival blebs with a median size of 0.7 mm, and eyes injected using 30-gauge and 32-gauge needles showed no subconjunctival bleb formation. CONCLUSION: Decreasing the IOP before intravitreous injection and using a smaller-gauge needle reduce the risk of drug reflux after intravitreous bevacizumab injection. CLINICAL RELEVANCE: Intravitreous injection is an increasingly common route of drug delivery to treat ocular diseases. Techniques that maximize bioavailability are examined in this study.