Incidence of increased intraocular pressure after subtenon injection of triamcinolone acetonide

Purpose: To determine the incidence of eyes that have an increase in the intraocular pressure (IOP) after subtenon injections of triamcinolone acetonide (TA). Methods: The medical records of 147 patients treated with single or multiple subtenon injections of TA (10 mg) were reviewed. The incidence of an IOP elevation (ΔIOP) ≥5 mmHg or an IOP of >21 mmHg was determined. The peak ΔIOP, defined as the difference in the IOP at the peak to the baseline IOP, was also evaluated. Multivariate analyses were used to evaluate the relation between the IOP elevation and the age, gender, refractive error, and lens status. Results: A ΔIOP ≥5 mmHg was found in 75 eyes (46%), and an IOP >21 mmHg was found in 48 eyes (30%) after a single injection of TA. The IOP increased within 3 months in 39 eyes (81%) and after 4 months in 9 eyes (19%). The IOP began to increase significantly from 2 weeks up to 5 months (P<0.05) and returned to the baseline IOP in 10 months. The incidence of ΔIOP ≥5 mmHg or an IOP of >21 mmHg after multiple subtenon injections of TA was significantly higher than after a single injection (62%; P=0.027, 47%; P=0.013, respectively). The incidence of IOP >21 mmHg and the peak ΔIOP were significantly related with younger age (P=0.002, P=0.021, Forward stepwise regression analysis). A weak but significant negative correlation was found between the peak ΔIOP and the age (r=-0.216, P=0.006, Pearson's correlation coefficient test), and the peak ΔIOP and the refractive error (r=-0.198; P=0.018). Conclusion: Repeated injections of TAs and injection of younger patients or myopic eyes increase the incidence of an IOP elevation.