To study systemic absorption of triamcinolone acetonide (TA) after posterior sub-Tenon injection.

Prospective, interventional case series.

The study was conducted in a tertiary care teaching hospital on 35 eyes in which posterior sub-Tenon injection of 40 mg TA was administered after conventional extracapsular cataract extraction. Patients who had received any systemic steroid over 6 weeks preceding the period of study or had inflammatory ocular conditions were excluded. Serum TA levels were estimated by high-performance liquid chromatography at 1, 2, 3, 24, and 48 hours and 1, 2, and 6 weeks after injection.

Significant levels of the drug were detected in 45.71% of samples (mean serum levels, 6.94 ± 8.98 ng/ml; P < .001) at 1 hour after sub-Tenon injection, in 85.71% of samples (mean serum levels, 21.83 ± 12.92 ng/ml; P < .001) at 2 hours after injection, in 100% of samples (mean serum levels, 47.14 ± 12.20 ng/ml; P < .001) at 3 hours after injection, in 100% of samples (mean serum levels, 35.49 ± 13.79 ng/ml; P < .001) at 24 hours after injection, in 62.86% of samples (mean serum levels, 10.46 ± 10.69 ng/ml; P < .001) at 48 hours after injection, and in 28.57% of samples (mean serum levels, 3.74 ± 6.45 ng/ml; P = .002) at 1 week after injection. The drug was not detected in any of the samples obtained 2 weeks and 6 weeks later.

Posterior sub-Tenon injection of 40 mg TA adds statistically significant quantities to physiologic concentration of corticosteroids in peripheral blood. This may be detrimental for patients having certain metabolic diseases like diabetes and preferably should be avoided or administered with caution.