Initially, ophthalmic therapy in the form of eyedrops was the mainstay of treatment. Because patient compliance and penetration success of medications can sometimes become an issue, many ophthalmologists have searched for better success with
intracameral injections. In this format, medication is delivered directly into the anterior chamber of the eye without need for modification by corneal esterases. Certainly concentrations achieved can be much higher than with externally applied drops, but is this safe for the patient?
Results from the ESCRS suggest not only is intracameral injection of antibiotics (in that case cefuroxime) safe, but beneficial in terms of a lower rate of endophthalmitis. Because of the issues surrounding antibacterial spectrum and difficulty in preparation, many physicians in the US have studied moxifloxacin (Vigamox, Alcon) for intracameral use and have found no deleterious effects (Lane SS, Osher RH, Masket S, Belani S. Evaluation of the safety of prophylactic intracameral moxifloxacin in cataract surgery. J Cataract Refract Surg. 2008 Sep;34(9):1451-1459). But prophylaxis is not the only area in which intracameral antimicrobial therapy is advantageous. Intracameral antifungal therapy has played a large role in the treatment of fungal keratitis, particularly in those patients with deep infections.
For the management of neovascularization, off-label intracameral use of anti-VEGF therapy has been useful in the treatment of neovascular glaucoma (Qureshi K, Kashani S, Kelly SP. Intracameral bevacizumab for rubeotic glaucoma secondary to retinal vein occlusion. Int Ophthalmol. 2008 Sep 14) Additionally, Maris and colleagues (Maris PJ Jr, Correnti AJ, Donnenfeld ED. Intracameral triamcinolone acetonide as treatment for endothelial allograft rejection after penetrating keratoplasty. Cornea. 2008 Aug;27(7):847-50) have found that intracameral steroid injection can help in resolution of endothelial allograft rejection after corneal transplantation. In both of these cases, no toxicity related to intracameral medication was found.
It would seem that intracameral therapy has a definite role in the treatment of ocular disease. As our understanding of the corneal endothelium and trabecular meshwork improve, we should expect further evolution in the development of intracameral medication with the possibility of one day eradicating the need for topical therapy altogether.
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