Intravitreal dexamethasone implant for recalcitrant cystoid macular edema secondary to retinitis pigmentosa: a pilot study

cited By 0International audienceBackground: To determine the utility of the intravitreal dexamethasone implant as therapy for cystoid macular edema (CME) secondary to retinitis pigmentosa (RP) recalcitrant to carbonic anhydrase inhibitor therapy over 2 years as a pilot study. Methods: This was a prospective case series. Patients who showed either an incomplete or no response to topical dorzolamide for at least 1 month and oral acetazolamide therapy for at least 15 days were recruited for the study with informed consent. A complete anterior and posterior segment examination was performed including fundus fluorescein angiography (FFA), optical coherence tomography scan (OCT) and electroretinogram to confirm the diagnosis. The dexamethasone implant was injected using a standardized technique. Follow ups were scheduled on days 1, 7, and 30 and then monthly thereafter for 2 years. The primary outcome measure was the change in corrected distance visual acuity (CDVA) and central subfield thickness (CST) at months 1, 6, 12, 18, and 24. The secondary outcome measure was complications, if any. Appropriate statistical analysis was done. Results: Five patients (two males; six eyes; median age 49 years) were recruited for the study. All patients required at least two injections over 2 years. All patients demonstrated significant improvement in CDVA (p = 0.004) as well as CST measurements (p = 0.0038) over 2 years. No complications were noted. Conclusion: The intravitreal dexamethasone implant provides significant improvement in CDVA and CST measurements in patients with recalcitrant CME secondary to RP. © 2017, Springer-Verlag Berlin Heidelberg

Synergistic locoregional chemoradiotherapy using a composite liposome-in-gel system as an injectable drug depot

Shruti GuhaSarkar,1 Kamal Pathak,2 Niyati Sudhalkar,3 Prachi More,1 Jayant Sastri Goda,3 Vikram Gota,2 Rinti Banerjee1 1Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, 2Department of Clinical Pharmacology, 3Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer, Navi Mumbai, Maharashtra, India Abstract: The use of radiosensitizers in clinical radiotherapy is limited by systemic toxicity. The biopolymeric, biodegradable, injectable liposome-in-gel-paclitaxel (LG-PTX) system was developed for regional delivery of the radiosensitizer paclitaxel (PTX), and its efficacy was evaluated with concurrent fractionated radiation. LG-PTX is composed of nano-sized drug-loaded fluidizing liposomes, which are incorporated into a porous biodegradable gellan hydrogel. This allows enhanced drug permeation while maintaining a localization of the drug depot. LG-PTX had an IC50 of 325±117 nM in B16F10 melanoma cells, and cytotoxicity with concurrent doses of fractionated radiation showed significant increase in apoptotic cells (75%) compared to radiation (39%) or LG-PTX (43%) alone. Peri-tumoral injection in tumor-bearing mice showed PTX localization in the tumor 2 hours after administration, with no drug detected in plasma or other organs. LG-PTX administration with doses of focal radiation (5×3 Gy) significantly reduced tumor volumes compared to control (6.4 times) and radiation alone (1.6 times) and improved animal survival. LG-PTX thus efficiently localizes the drug at the tumor site and synergistically enhances the effect of concurrent radiotherapy. This novel liposome-in-gel system can potentially be used as a platform technology for the delivery of radiosensitizing drugs to enhance the efficacy of chemoradiotherapy. Keywords: radiosensitizer, hydrogel, regional drug delivery, concurrent radiotherapy, lipid nanocarrie

Synergistic locoregional chemoradiotherapy using a composite liposome-in-gel system as an injectable drug depot

The use of radiosensitizers in clinical radiotherapy is limited by systemic toxicity. The biopolymeric, biodegradable, injectable liposome-in-gel-paclitaxel (LG-PTX) system was developed for regional delivery of the radiosensitizer paclitaxel (PTX), and its efficacy was evaluated with concurrent fractionated radiation. LG-PTX is composed of nano-sized drug-loaded fluidizing liposomes, which are incorporated into a porous biodegradable gellan hydrogel. This allows enhanced drug permeation while maintaining a localization of the drug depot. LG-PTX had an IC50 of 325 +/- 117 nM in B16F10 melanoma cells, and cytotoxicity with concurrent doses of fractionated radiation showed significant increase in apoptotic cells (75%) compared to radiation (39%) or LG-PTX (43%) alone. Peri-tumoral injection in tumor-bearing mice showed PTX localization in the tumor 2 hours after administration, with no drug detected in plasma or other organs. LG-PTX administration with doses of focal radiation (5x3 Gy) significantly reduced tumor volumes compared to control (6.4 times) and radiation alone (1.6 times) and improved animal survival. LG-PTX thus efficiently localizes the drug at the tumor site and synergistically enhances the effect of concurrent radiotherapy. This novel liposome-in-gel system can potentially be used as a platform technology for the delivery of radiosensitizing drugs to enhance the efficacy of chemoradiotherapy