tailieunhanh - Intraocular Drug DelIvery - part 9

Đôi mắt nghiên cứu đã cải thiện đáng kể độ dày võng mạc trong khi mắt điều khiển đã không thay đổi đáng kể ở 12 tuần (P | 294 Rana and Pearson significantly greater VA improvement postintravitreal triamcinolone compared with the group without cystoid foveal edema. In another study Massin et al. 31 selected 12 patients with bilateral DME and randomly assigned one of the eyes to receive 4 mg of intravitreal triamcinolone while the other eye was simply monitored control . The study eyes had significantly improved retinal thickness while the control eyes did not change significantly at 12 weeks P . The appropriate intravitreal triamcinolone dose has not yet been established. The ISIS study compares 2 mg versus 4 mg of triamcinolone in patients with macular edema. Preliminary data indicates that the 4 mg dose is more effective at treating macular edema 30 . Two studies by Jonas et al. 32 33 in Europe demonstrated measurable vitreous triamcinolone for seven to eight months and years respectively after an injection of 20-25 mg of the drug. Prospective trials that compare the 20-25 mg dose to lower doses will be necessary to clarify the optimal dosing regimen. Intravitreal injections to deliver corticosteroids minimize systemic side effects however they may be associated with complications such as retinal detachment retinal tears vitreous hemorrhage endophthalmitis increased intraocular pressure IOP cataract formation and with repeated use required for successful treatment fibrosis and ptosis. The most common side effect is increased IOP which has been found on rare occasion to increase drastically up to 50 mmHg in one case report by Detry-Morel et al. 16 34 35 . Close IOP monitoring is crucial following intra-vitreal injection. INTRAVITREAL FLUOCINOLONE ACETONIDE IMPLANT RETISERT Several drug delivery systems for the sustained release of medication within the posterior segment are either under investigation or already in clinical use 36-38 . These systems offer a promising approach to the treatment of ocular diseases in cases where systemic drug administration may be associated .