Intravitreal injection intraocular pressure

Jonas JB, Kreissig 1, Degearing R. Intraocular pressure after intravitreal injection of triamcinolone acetonide. Br J Ophthalmol 2003 87 24-27. 

In 150 patients who were given intravitreous fomivirsen 165 micrograms/injection (35 eyes, 30 patients) or two different regimens of 330 micrograms/injection (142 eyes, 110 patients), anterior chamber inflammation and increased intraocular pressure were dose-related and schedule-dependent 165 micrograms/injection, 4.1... 

Optimal steroid therapy for PVR would maintain therapeutic levels in the vitreous for a prolonged period at present this can only be achieved by prohibitively high systemic dosing or intravitreal injections (which do not maintain constant drug levels). A sustained release device that maintains constant therapeutic intravitreal levels with minimal systemic exposure may prove useful in the clinical management of PVR, although the potential for ocular effects such as elevation of intraocular pressure and cataract cannot be ignored. 

The efficacy of RA in PVR has been evaluated in animal models. A single intravitreal injection of RA used in conjunction with silicone oil reduces the incidence of traction retinal detachment (40). Use of microsphere encapsulation of RA to prolong the intravitreal half-life reduced the incidence of PVR in the rabbit model by 64% (41). Intravitreal RA suspended in 1% sodium hyaluronate has also been studied in a rabbit model of PVR and has similar inhibitory effect on PVR progression. The authors suggested that in cases in which silicone oil was not necessary, sodium hyaluronate could be used as an RA vehicle, though transient elevations of intraocular pressure could be expected (42). 

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 50mmHg in one case report by Detry-Morel et al.) (16,34,35). Close IOP monitoring is crucial following intravitreal injection. 

The series of clinical trials that led to approval by the U.S. Food and Drug Administration involved 430 eyes in 330 patients. Fomivirsen significantly delayed progression of CMV retinitis in patients with AIDS, including those who had failed treatment with ganciclovir or foscarnet, the first-line therapies. Fomivirsen is administered by intravitreal injection at doses of 165 pg once weekly for three weeks of induction and then once every two weeks. It also can be administered In a dose of 330 pg on days 1 and 15 and then once a month thereafter. Mean maximum retinal concentrations of fomivirsen occur at 2 days, and the elimination half-life after a single, 115-pg dose in monkey retina was 78 hours. There are no systemic side effects. Ocular side effects include Increased intraocular pressure and mild to moderate intraocular inflammation that can be reversed with topical steroid treatment. It is important that side effects be minor, because treatment will be lifelong. 

Sensory systems Eyes A transient increase in intraocular pressure has also been reported 0-30 minutes after intravitreal injections. In one study intraocular pressure rose as early as 5 seconds after intravenous injection of ranibizumab [11 ]. The mean pressure after 5 seconds was 44 (range 22-59) mmHg it was higher in eyes with shorter axial lengths. 

Gismondi M, Salati C, Salvetat ML, Zeppieri M, Brusini P. Short-term effect of intravitreal injection of ranibizumab (Lucentis) on intraocular pressure. J Glaucoma 2009 18 658-61. 

Kim JE, Mantravadi AV, Hur EY, Covert DJ. Short-term intraocular pressure changes immediately after intravitreal injections of anti-vascular endothelial growth factor agents. Am J Ophthalmol 2008 146 93(1A. 

Skahcky SE, Ho 1, Bank A. Glaucoma filtration surgery following sustained elevation of intraocular pressure secondary to intravitreal anti-VEGF injections. Ophthalmic Surg Lasers Imaging Retina 2012 43(4) 328-34. 

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