Antiviral intravitreal injections

FDA approved intraocular injections include mio-tics, viscoelastics, and viscoadherents and an antiviral agent for intravitreal injection. The approved intraocular miotics, carbachol (Miostat ) and acetylcholine (Miochol ), are injected into the anterior chamber at the end of cataract surgery to constrict the pupil and allow the iris to cover the implanted intraocular lens. Carbachol is formulated in a BSS vehicle in sterile water for injection at a physiological pH... 

A new antiviral agent, developed for treatment of CMV retinitis, can be administered by intravitreal injection. Formivirsen sodium is a phosphorothioate oligonucleotide that inhibits CMV replication through an antisense mechanism. It is formulated as a sterile and preservative-free solution and supplied in single-use vials (Vitravene ). The product is administered directly into the vitreous cavity posterior to the limbus through a 30-gauge needle. This procedure can be performed on an... 

Liposomal encapsulation has the potential not only to increase the activity and prolong the residence of the drag in the eye, but also to reduce the intraocular toxicity of certain potent drags such as antimetabolites, antivirals and antibiotics to the retina. For example, liposome-encapsulated amphotericin B produced less toxicity than the commercial amphotericin B solution when injected intravitreally. Liposomes have also been used to study the release and distribution of dyes, which in turn reflect the integrity of the retinal vascular constitution. Direct intravitreal injection of liposomal-encapsulated drags has shown enhanced vitreal levels for extended periods of time in the vitreous of rabbit models. Liposomal encapsulation of the antiviral, HPMPC, reduces the toxic effects to the retina and provides therapeutic levels against CMV retinitis for up to 8 months. 

As mentioned above, intravitreal injection of drugs should be used in many cases to achieve therapeutic intravitreal drug levels. This is especially true for cases of viral retinitis, such as cytomegalovirus (CMV) retinitis and acute retinal necrosis (ARN) which require intravitreal injection of antivirals, or for the treatment of bacterial and fungal endophthalmitis or proliferative vitreoretinopathy [305]. It still remains a controversial issue whether liposomes can reach the retina after intravitreal injections and which vesicle physicochemical characteristics should be preferred for such formulations. 

The FDA approved intraocular injections include miotics, triamcinolone acetonide, pegaptanib sodium, ranibizumab, formivirsen sodium, viscoelastics and viscoadherents, and an antiviral agent for intravitreal injection. There are many small and large molecules currently in clinical trials that are delivered via intravitreal injection for the treatment of a variety of retinal diseases with a large area of focus on the treatment of AMD and macular edema. 

Intraocular (or intravitreal) injections, containing active substances such as triamcinolone, antivascular endothelial growth factor (VEGF) inhibitors, antibiotics, antivirals, or antifungals, are administered into the eye. 

Viral endophthalmitis has become a major concern in AIE management, and some of uveitis are shown to arise from viral origin (e.g. acute retinal necrosis). Intravitreal antiviral therapy is surely one of the crucial modalities. The b-wave, the c-wave, the oscillatory potentials and the VEP remained unchanged after 5 repetitive weekly (once a week) intravitreal injections of 200 pig ganciclovir. 

B V ara U is a newly-developed antiviral drug particularly effective to varicella zoster virus. No changes in the b-wave, the c-wave or the oscillatory potentials were induced by an intravitreal injection of 100 pig BV area U or by intravitreal irrigation with 20 pig/m BV ara U. The concentration of BV ara U after an oral administration was much lower in the vitreous than in the serum, which indicates that intraocular penetration of B V ara U is very poor. Furthermore, an enteral use of B V ara U in conjunction with some of antimetabolites reportedly causes serious systemic adverse effects. Therefore, a topical intraocular application of BV ara U is much preferable. 

Antiviral agents are sometimes injected intravitreally for treatment of cytomegalovirus (CMV) retinitis in patients... 

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