Injections periocular

Figure 3-17 Relative positions of periocular injections. A, Subconjunctival B, sub-Tenon s C, retrobulbar.

Periocular injection of steroids should be reserved for those situations requiring an anti-inflammatory effect greater than that obtainable with topical or systemic administration. Concurrent administration of steroid by both topical and subconjunctival routes does appear to produce an additive therapeutic effect in severe inflammations, but periocular injection alone does not necessarily result in greater anti-inflammatory effects.These fects suggest that topical administration should be the primary route of steroid therapy for anterior segment inflammations. Table 12-3 compares the achmitages and disachmitages of the three routes of steroid administration. 

Leibowitz HM, Kupferman A. Periocular injection of corticosteroids. Arch Ophthalmol 1977 95 311-314. 

The anti-inflammatory effects of corticosteroids reduce CME, vitreous inflammation, and retinal vasculitis. Use of corticosteroids is especially important if the macular area is threatened. Because they are immunosuppressive, they should never be used without concurrent antimicrobial agents. Oral prednisone 40 to 60 mg is given daily for 2 to 6 weeks depending on clinical response. Topical corticosteroids are used for the secondary anterior chamber reaction but have no impact on retinal inflammation, and periocular injections should be used cautiously, if at all, because of their intense anti-inflammatory activity. 

An 80-year-old woman had severe difficulty in swallowing and flaccid paralysis of her cervical muscles starting 4 days after the periocular injection of botulinum toxin 120 MU for blepharospasm (12). She also developed bilateral facial nerve paralysis and slurred speech and could not fully close her eyes. Barium swallow and fluoroscopy showed signs of aspiration. The serum concentration of antiacetylcholine receptor antibodies was 6.9 units (reference range 0-0.7 units). Mestinone and prednisone improved her symptoms. She had been treated with botulinum toxin on 18 occasions over the previous 13 years without any untoward effects. 

Topical instillation 218 Periocular injections 220 Intraocular injections 220 Parenteral administration 220 Innovative drug delivery systems 221... 

Periocular injections physically bypass the external ocular epithelial barriers. Three techniques may be used ... 

Periocular injections, subconjunctival, subtenons, and retrobulbar injection of drugs have been frequently investigated as a means to increase ocular availability. Subtenon injections of steroids, such as triamcinolone acetonide, are frequently used to control inflammatory conditions of the posterior segment such as cystoid macular edema, although this delivery route carries a risk of inadvertent intraocular injection (45). 

The ocular bioavailability from periocular injections is not well studied and the routes by which drugs penetrate the eye after such injections have never been satisfactorily elucidated. Levine and Aronson (46) used radiopaque media to demonstrate the diffusion of injected compounds from these sites in rabbits and found that subtenons and subconjunctival injections disperse and spread circumferentially around the eye but do not diffuse back to the orbit, while retrobulbar injections tend... 

Intraocular injections are associated with significant complications and often must be repeated at regular intervals in patients with a chronic disease such as uveitis. Similar difficulties are associated with periocular injections although the complication rate is lower and those that do occur are usually less severe. The main... 

Corticosteroids have been used to treat a variety of ocular diseases. Traditionally, delivery of corticosteroids for posterior-segment eye diseases has been achieved through oral systemic therapy and periocular injections. Oral corticosteroids have not been widely used to treat DME, but when used for posterior inflammatory uveitis, they require high concentrations to reach therapeutic levels in the posterior segment. These high doses often result in systemic side effects (24). Periocular corticosteroid administration often must be repeated and may be associated with complications such as ptosis and inadvertent needle penetration of the globe. 

As discussed previously, corticosteroids downregulate VEGF production in experimental models and possibly reduce breakdown of the blood retinal barrier (15,16). Similarly, corticosteroids have antiangiogenic properties possibly due to attenuation of the effects of VEGF (20,21). These properties of steroids are commonly used. Clinically, triamcinolone acetonide is used locally as a periocular injection to treat cystoid macular edema secondary to uveitis or as a result of intraocular surgery (22,23). In animal studies, intravitreal triamcinolone acetonide has been used to prevent proliferative vitreoretinopathy and retinal neovascularization (24—27). Intravitreal triamcinolone acetonide has been used clinically to treat proliferative vitreoretinopathy and choroidal neovascularization (28-31). 

Most ocular diseases like dryness, conjunctiva, and eye flu are treated by topical drug application in the form of solutions, suspensions, and ointment. In the earlier period, drug delivery to the eye has been limited to topical application, redistribution into the eye following systemic administration, or direct intraocular/periocular injections. However, one of the major barriers of ocular medication is to obtain and maintain a therapeutic level at the site of action for a prolonged period of time. 

Some ocular diseases require specific treatment given via intravitreal or periocular injection into the eye. 

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