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Objective. To determine the dose response and toxicity threshold of micro-collimated X-rays delivered to porcine maculae by a stereotactic radiosurgical system after 270 days. Methods. Twelve eyes of six Yucatan mini-swine were randomized to receive up to 90 Gy to the retina, using an office-based trans-pars plana delivery system. To determine the safety profile of this radiation delivery, ophthalmic examination, fundus photography, fluorescein angiography (FA), and spectral domain optical coherence tomography (SD-OCT) were obtained at multiple time points up to 270 days post treatment. Results. No abnormalities were noted on external examination. Cataracts were noted in 4 of 12 eyes. Dose and time-dependent changes were noted on fundus examination, FA, ICG and SD-OCT. No significant abnormalities were seen in the control, 16 Gy or 24 Gy groups using any modality. Histopathology revealed a dose response effect with no discernable lesions in the 16 Gy group. Conclusion. The X-ray delivery system precisely targets the porcine retina in vivo with little effect on surrounding structures. No ophthalmic or intracranial adverse effects were noted at clinically relevant doses at 270 days following radiation delivery.

Abstract  Fenretinide is a synthetic retinoid that interferes with the attachment of retinol to retinol binding protein. It may inhibit accumulation of A2E and lipofuscin, and is proposed as therapy for Stargardt disease. It is currently used for cancer therapy, and mild depression of rod function and dark adaptation is a side effect at standard dosage. We studied two youngsters (aged between 12 and 13) receiving high doses as compassionate treatment for neuroblastoma: 800 mg daily for 1 out of every 3 weeks, for roughly 2 years. Goldmann-Weekers dark adaptometry, ISCEV standard ERG and mfERG were performed, and blood was analyzed for vitamin A. Neither child complained of night blindness or showed retinal fundus abnormalities. On initial exam, dark adaptation thresholds were elevated by 3 log units, and there were no detectable rod ERG responses. However, cone responses and mfERG were normal. Retesting one subject 3 months after stopping the drug revealed normal rod thresholds (slightly delayed) and low normal rod ERG responses. Serum vitamin A levels were normal from both subjects, but there is no record of whether the samples were drawn during cycles on or off drug. Our study demonstrates that high dose Fenretinide can suppress rod function quite completely, although serum vitamin A and rod function apparently return to normal or near normal levels rapidly once the drug is stopped. It is intriguing that cone function and access to vitamin A seems largely independent of Fenretinide effects on retinol availability. [ABSTRACT FROM AUTHOR]

Abstract Background  To describe the occurrence of ocular hypertension in four patients following injection of ranibizumab intravitreally. Methods  Case series. Results  Four patients had high intraocular pressure after intravitreal ranibizumab 0.5 mg. Ocular hypertension occurred 1 month after the second ranibizumab injection in patients 1 and 3, and 1 month after the first ranibizumab in patient 2. In patient 4, it occurred several hours after the first ranibizumab injection. In all patients, the IOP increase was sustained across several visits, requiring control with topical glaucoma therapy, and in two cases the addition of a systemic carbonic anhydrase inhibitor. None of the patients had a previous history of glaucoma, ocular hypertension or IOP asymmetry and the IOP was as high as 30, 34, 46, and 50 mmHg in the four patients. Conclusion  Severe and sustained ocular hypertension may occur after intravitreal ranibizumab. Although the mechanism of the pressure rise is unknown, all eyes in our series were controlled with medical therapy. [ABSTRACT FROM AUTHOR]

Abstract Purpose  The purpose was to report a case of elevated intraocular vascular endothelial growth factor (VEGF) levels in a 2-year-old boy with stage 4 Coats disease. Design  Interventional case report. Methods  A 2-year-old boy with severe Coats disease and complex retinal detachment refractory to surgical intervention underwent two injections of intravitreal pegaptanib sodium in his right eye 8 weeks apart. Results  After intravitreal injection there was a marked reduction in VEGF (908 to 167 pg/ml) levels and improvement of exudation, hemorrhage, and nearly complete reattachment of his retina within 3 weeks of treatment. The patient remains stable 6 months post-treatment. Conclusions  Coats disease may have a component of dysregulation of VEGF-mediated angiogenesis as evidenced by elevated levels in this patient. [ABSTRACT FROM AUTHOR]