Intraocular pressure rise is predictive of vision improvement after intravitreal triamcinolone acetonide for diabetic macular oedema: a retrospective analysis of data from a randomised controlled trial

BACKGROUND: Intravitreal triamcinolone acetonide (IVTA) is an effective treatment for recalcitrant diabetic macular oedema (DMO). It has been shown to improve vision with benefits persisting up to five years. The most common initial side effect of IVTA treatment is rise in intraocular pressure, occurring in approximately 50% of patients within the first 6 months of treatment. We evaluated whether there is a correlation between the development of intraocular pressure rise and improvement in vision. METHODS: Analysis of individual data from 33 eyes of 33 participants treated with IVTA for DMO from a prospective, randomised, double-masked, placebo controlled trial. The degree of intraocular pressure (IOP) rise was correlated with improvement in best-corrected visual acuity (BCVA) at 1 and 6 months. RESULTS: The proportion of eyes gaining 5 or more logMAR letters was higher in eyes with greater IOP rise (p = 0.044). Better absolute improvement in BCVA at 6 months (p = 0.045) was also found in eyes with greater IOP rise. Regression analyses revealed a correlation between IOP rise of 10 or more mmHg and absolute BCVA improvement at 6 months (odds ratio 1.22, 95% confidence interval 1.01-1.48, p = 0.039), but not at 1 month. CONCLUSIONS: IOP rise and vision improvement appear to be correlated following IVTA for DMO, suggesting that the mechanisms that cause both may be linked. TRIAL REGISTRATION: Clinical trials.gov NCT00167518, September 5, 2005.