Comparison of 4 mg versus 20 mg intravitreal triamcinolone acetonide injections.

AIMS

To compare the non-decanted (standard) 4 mg versus the decanted 20 mg intravitreal triamcinolone acetonide (IVTA) injections and to assess their effect on intraocular pressure (IOP).

METHODS

We retrospectively reviewed the records of 92 consecutive eyes, which received an intravitreal injection of either dose of triamcinolone acetonide, at a single retina centre. The change in IOP (elevation of at least 5 mm Hg from baseline or above 21 mm Hg) was analysed with a multivariate logistic analysis. The mean follow-up period in both groups was 27 weeks. A subgroup analysis comparing vitrectomised to non-vitrectomised eyes in both groups was also performed.

RESULTS

Of the 92 eyes, 46% (23 of 51) in the 4 mg group versus 30% (12 of 41) in the 20 mg group had an IOP >21 mm of Hg (p = 0.14) after a mean follow-up period of 27 weeks. The vitrectomised eyes (3 of 24) in the 20 mg group had a significantly lower rate of IVTA induced IOP elevation than the non-vitrectomised eyes (9 of 17) (p = 0.013). The IOP elevation occurred significantly earlier in the 4 mg group (vitrectomised eyes 27 (SD 43) days and non-vitrectomised eyes 61 (52) days) than in the 20 mg group (vitrectomised eyes 104 (56) days and non-vitrectomised eyes 119 (82) days), independent of the vitreous status (vitrectomised p = 0.05 and non-vitrectomised p = 0.04). The mean value of initial high IOP in the non-vitrectomised eyes was higher in the 4 mg group than in the corresponding 20 mg group (p = 0.048).

CONCLUSION

Decanted 20 mg IVTA may not pose a significantly greater risk of IOP elevation than the 4 mg non-decanted IVTA.