The effect of deep posterior subtenon injection of corticosteroids on intraocular pressure.

PURPOSE: To investigate the effect of posterior subtenon injections of corticosteroids on intraocular pressure in a variety of ocular diseases. METHODS: We retrospectively analyzed 202 consecutive posterior subtenon corticosteroid injections (148 of methylprednisolone acetate, 80 mg, and 54 of triamcinolone acetonide, 40 mg) in 63 eyes of 55 patients (26 male, 29 female; mean age +/- SD, 60.17 +/- 26.55 years). All patients had received topical or systemic corticosteroids before the injection, and no rise in intraocular pressure had been noted. Preinjection and postinjection intraocular pressure measurements were compared by two-tailed paired t test. Statistical analysis was performed separately by patient (first injection of first injected eye), by eye (first injection of each eye), and by all injections. To detect increase in intraocular pressure during follow-up, statistical analysis was performed separately 14 to 90 days, 91 to 150 days, and 151 to 270 days after injection. RESULTS: No statistically significant difference was found between preinjection and postinjection intraocular pressure measurements. A power calculation in the most stringent subanalysis (by patient) proved that there is only a 3.87% chance to statistically miss a clinically significant rise in intraocular pressure from 15 to 21 mm Hg. CONCLUSIONS: Posterior subtenon injection of corticosteroids does not cause an increase in intraocular pressure. All patients in our study had been treated previously with topical or systemic corticosteroids and did not react with an excessive increase in intraocular pressure. This safety of repository corticosteroids may therefore not apply to patients whose status in responding to corticosteroids is not known.