Abstract
Purpose: :
to conduct a clinical trial to provide information on efficacy and safety of low dose of preservative–free IVTA (IntraVitreal Triamcinolone Acetonide).
Methods: :
We filtered commercially available TA suspension through a porous membrane filter (pore size 0,2 µm; Millex–FG, Millipore Co, Cork, Ireland). We measured the TA concentration using ultraviolet visible spectophotometer (Dinko uv–7500). We backflushed the filter with 1.0 ml. of BSS sterile irrigation solution (Alcon Laboratories, UK) and measured the TA concentration. TA suspensions prepared as described earlier were used in 57 patients with macular edema occurring in age–related exudative maculopathy (10) in diabetic retinopathy (25), branch retinal vein occlusion (14), pseudophakia (8). Patients were followed–up for at least 6 months.
Results: :
TA concentration obtained from backflushing the filter with 1.0 ml. of BSS was 2,52 mg/0.1mL. Patients experienced significant vision improvement after 1 month (0.85 vs 0.68 LogMAR) but this improvement did not sustained at 6 months follow–up. Ocular Hypertension developed in one third of patients after 6 months, who were satisfactorily controlled with topical treatment. Sterile pseudoendophthalmitis appeared in two patients, and we did not appreciate significant cataract progression in any patient after 6 months follow–up.
Conclusions: :
Common side effects of IVTA ,cataract and intraocular pressure elevation, occurs also with the use of low dose preservative–free TA. It has been suggested that noninfectious endophthalmitis probably represents a toxic reaction to the drug, the vehicle in which is suspended, or a contaminant in the vials in which is delivered. We believe that preservatives or vehicles may not be the true cause of sterile pseudo–endophthalmitis. There is a strong need for formulation of triamcinolone originally developed for intraocular use.
Keywords: drug toxicity/drug effects • corticosteroids • pharmacology