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Dive into the research topics where D. Ossandón is active.

Publication


Featured researches published by D. Ossandón.


Journal of Aapos | 2014

Using cost-effective intra-arterial chemotherapy to treat retinoblastoma in Chile

D. Ossandón; M. Zanolli; Verónica Pérez; Paulo Zúñiga; Álvaro Belmar; Mónica Varas; Carol L. Shields

Intra-arterial chemotherapy (IAC) has proved to be an effective treatment for retinoblastoma, but can be very expensive in developing countries. We report 2 patients from Chile in whom IAC resulted in globe salvation. Both patients had their medical care provided by the public health system and had failed standard therapy.


Journal of Aapos | 2009

Unilateral eyelid angiofibroma with complete blepharoptosis as the presenting sign of tuberous sclerosis

Juan Pablo Lopez; D. Ossandón; Patricio Miller; Lorena Sánchez; Augusto Winter

Tuberous sclerosis is a multisystem autosomal-dominant disease characterized by hamartomatous growths in the brain, skin, kidneys, eyes, and heart, but it may affect almost any organ. Retinal hamartomas are 1 of the major diagnostic criteria for tuberous sclerosis and occur in approximately 50% of patients. Nonretinal findings include angiofibromas of the eyelid, strabismus, and pseudo-colobomas of the lens and iris. We report a case of a newborn with congenital eyelid angiofibroma mimicking complete congenital blepharoptosis that was revealed by central nervous system imaging to be part of the tuberous sclerosis complex.


JAMA Ophthalmology | 2018

Treatment of Nonmetastatic Unilateral Retinoblastoma in Children

Verónica Pérez; Claudia Sampor; Guadalupe Rey; Andreu Parareda-Salles; Katherine Kopp; Agustín Dabezies; Gustavo Dufort; Marta Zelter; Juan Pablo Lopez; Marcelo Urbieta; Elisa Alcalde-Ruiz; Jaume Català-Mora; Mariona Suñol; D. Ossandón; Adriana Fandiño; J. Oscar Croxatto; María T.G. de Dávila; Gregory Reaman; Yaddanapudi Ravindranath; Guillermo L. Chantada

Importance Multi-institutional collaborative studies that include large patient populations for the management of retinoblastoma with histopathological risk factors could provide important information for patient management. Objective To evaluate the implementation of a strategy for the management of nonmetastatic unilateral retinoblastoma in children based on standardized diagnostic and treatment criteria. Design, Setting, and Participants This single-arm prospective study applied a strategy based on a single-center experience. The setting was a multicenter study in Latin America (Grupo de America Latina de Oncologia Pediatrica [GALOP]). Participants were children with nonmetastatic unilateral retinoblastoma (staged with the International Retinoblastoma Staging System). The study opened on July 1, 2008, and closed on December 31, 2014. Follow-up was updated until June 30, 2017. Interventions Stage 0 patients (without enucleation) were given conservative therapy without a protocol. Stage I patients (with enucleation and no residual tumor) were divided into a high-risk group (retrolaminar invasion and/or scleral invasion) and a low-risk group (all remaining patients). High-risk children received adjuvant chemotherapy with 4 alternating cycles of regimen 1 (cyclophosphamide [65 mg/kg/d] [plus sodium-2-mercaptoethane sulfonate], idarubicin hydrochloride [10 mg/m2/d], and vincristine sulfate [0.05 mg/kg/d]) and 4 cycles of regimen 2 (carboplatin [500 mg/m2/d, days 1 and 2] and etoposide [100 mg/m2/d, days 1-3]). Low-risk children did not receive adjuvant therapy. Children with buphthalmia received neoadjuvant and adjuvant chemotherapy for a total of 8 cycles. Main Outcomes and Measures Probability of event-free survival (extraocular relapse and death from any cause were considered events). Results Among 187 children registered in the study, 175 were evaluable (92 [52.5%] female; median age, 22 months; age range, 3-100 months). Forty-two were stage 0 children, 84 were stage I low-risk children, and 42 were stage I high-risk children; there were 7 children in the buphthalmia group. With a median follow-up of 46 months, the 3-year probability of event-free survival was 0.97 (95% CI, 0.94-0.99), and the probability of overall survival was 0.98 (95% CI, 0.94-1.00). Stage 0 patients had no events, stage I low-risk patients had 1 event (orbital relapse treated with second-line therapy), stage I high-risk patients had 2 events (1 central nervous system relapse and 1 death from sepsis), and the buphthalmia group had 1 event (orbital relapse, followed by central nervous relapse and death). Conclusions and Relevance Adjuvant therapy may be effective for high-risk unilateral retinoblastoma but is toxic, and neoadjuvant chemotherapy for buphthalmus appears feasible.


Archivos de la Sociedad Española de Oftalmologia | 2017

Resultados anatómicos y refractivos en pacientes tratados por retinopatía del prematuro

M. Lolas; A. Tuma; M. Zanolli; R. Agurto; R. Stevenson; D. Ossandón

OBJECTIVE To describe the anatomical and refractive outcomes after treatment with intravitreal bevacizumab or laser in a patient cohort with retinopathy of prematurity (ROP). METHODS A multicentre, prospective, and observational study was performed on patients with ROP treated at Hospital Roberto del Río. Those patients with less than 6months of follow-up were excluded. Cases with posterior zone II, zone I ROP, and aggressive posterior ROP (AP-ROP) were treated with intravitreal bevacizumab. All other patients were treated with laser. Follow-up was performed every 3 months, and included fondo evaluation, refraction, and Teller tests. RESULTS The treated group included 144 eyes of 72 patients, of whom 49 were treated with laser and 23 with intravitreal bevacizumab. One (1.4%) patient from the laser group progressed to stage 4b retinal detachment and required bilateral vitrectomy. Of the remainder, 45 cases had type 1 ROP, 16 had threshold disease, and 11 had AP-ROP. The median of gestational age was 26 weeks (range 23-30), and median of birth weight was 800g (range 405-1350). Median follow-up was 10 months (range 6-8). The Teller test median was 3.2 cycles/cm (range 0.32-13). There were 16 (22%) cases with a myopic refraction of -6 D or more. The sphere median was -1.75 D (range -16.00 to +3.50 D) and the cylindrical median was 0.00 (range -4.5 to +1.5 D). Anatomical success was achieved in 71 (98.6%) of patients. CONCLUSION Treatment with laser or intravitreal bevacizumab is a highly successful primary treatment for ROP. Anatomical success can be achieved in most cases. Treated patients develop frequent and severe refractive defects, which should be corrected. Vision outcome, measured using the Teller preferential test, shows good results.


Archivos de la Sociedad Española de Oftalmología | 2015

Telemedicine correlation in retinopathy of prematurity between experts and non-expert observers

D. Ossandón; M. Zanolli; J.P. López; R. Stevenson; R. Agurto; C. Cartes


Journal of Aapos | 2017

A national telemedicine network for retinopathy of prematurity screening

Mario Zanolli; D. Ossandón; Ricardo Stevenson; Ricardo Agurto; Gad Dotan


Archivos de la Sociedad Española de Oftalmología | 2016

Molecular diagnosis in patients with retinoblastoma: Report of a series of cases

D. Ossandón; M. Zanolli; J.P. López; Felipe Benavides; V. Pérez; Gabriela M. Repetto


Archivos de la Sociedad Española de Oftalmología | 2016

Diagnóstico molecular en pacientes con retinoblastoma: reporte de una serie de casos

D. Ossandón; M. Zanolli; J.P. López; Felipe Benavides; V. Pérez; Gabriela M. Repetto


Archivos de la Sociedad Española de Oftalmología | 2017

Anatomical and refractive outcomes in patients with treated retinopathy of prematurity

M. Lolas; A. Tuma; M. Zanolli; R. Agurto; R. Stevenson; D. Ossandón


Journal of Aapos | 2016

Bilateral retinoblastoma with one eye manifesting only posterior chamber infiltration and no retinal involvement

D. Ossandón; Alan Kastner; M. Zanolli; Federica Solanes; Verónica Pérez; Gabriela M. Repetto; Felipe Benavides; Carol L. Shields

Collaboration


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M. Zanolli

Universidad del Desarrollo

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Felipe Benavides

Universidad del Desarrollo

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R. Agurto

Universidad del Desarrollo

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R. Stevenson

Universidad del Desarrollo

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Verónica Pérez

Universidad del Desarrollo

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A. Tuma

Universidad del Desarrollo

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Federica Solanes

Pontifical Catholic University of Chile

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J.P. López

Universidad del Desarrollo

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Juan Pablo Lopez

Universidad del Desarrollo

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