Aim To evaluate the efficacy of the fixed combination ocular hypotensive therapies compared to their non-fixed components used concomitantly for lowering intraocular pressure (IOP) in glaucoma and ocular hypertension.
Methods A systematic review of the literature, up to May 2007, without limits on year or language of publication was performed. Seven randomised controlled trials (n=2,083 eyes) were identified. Assessment of methodological quality was made using standardised criteria. Results were pooled quantitatively using meta-analysis methods and statistical analysis was performed using STATA® software. The difference in mean intraocular pressure (mmHg) from baseline between the fixed combination and non-fixed component therapies was compared. Non-inferiority in terms of efficacy was set at an upper confidence limit of ≤1.5mmHg for all time points (hour 0, hour 2 and hour 8) and evaluated at 12 weeks. Safety was evaluated from data on adverse events as reported in the included studies.
Results Of the 679 abstracts identified, 7 randomised controlled trials met the selection criteria. The quality scores of included studies were high, (mean of 29.4, maximum score 30). The mean differences (95% CI) and p-values at 12 weeks were as follows: 0.200mmHg, (CI -0.106 to 0.507), p=0.20 for Hr0, 0.393mmHg (CI 0.038 to 0.747), p=0.03 for Hr2 and 0.501mmHg (CI 0.156 to 0.846), p = 0.004 for Hr8. Although both Hr2 and Hr8 showed statistical significance favouring the non-fixed combinations, the non-inferiority measure ≤1.5mmHg upper confidence limit was not exceeded.
Conclusions Fixed combination therapies are equally safe and effective at lowering IOP as their non-fixed components administered concomitantly.