Latanoprost versus timolol as first choice therapy in patients with ocular hypertension
Purpose: To determine the cost-effectiveness of ocular hypertension (OH) treatment initiated with latanoprost compared to timolol. Methods: Two strategies for OH therapy are modelled, (1) 'starting with timolol' and (2) 'starting with latanoprost'. Therapy can be maintained or changed dependent on the achieved intraocular pressure (IOP) and side-effects. Adjustments of therapy to reach a target pressure involve monotherapy, combination therapy and laser. Four drugs are used: latanoprost, timolol, brimonidine and dorzolamide. Once the adjustments of therapy are completed, lifelong follow-up with IOP-dependent conversion to glaucoma and progression to blindness are modelled. Direct medical costs are assigned. The IOP-lowering effect of drugs is based on meta-analyses and applied by Monte Carlo simulation to a hypothetical cohort of patients with OH. The characteristics of the cohort, including the initial IOP distribution, are based on data of 1000 patients. Results: The IOP decreased from 25,4 mm Hg (mean) to 16.7 (±0.017) mm Hg (strategy 1) and to 16.5 (±0.013) mm Hg (strategy 2). Costs per patient within 15 months of therapy were € 367 and € 469, respectively. Lifetime blindness and costs were 0.0334 years and € 3 514 (strategy 1) and 0.0318 years and € 4 397 (strategy 2). Incremental costs per year of vision saved for strategy (2) in comparison with strategy (1) amount to, given the uncertainties in the model, approximately € 537 000. Conclusion: For saving 1 year of vision, high costs are needed when OH therapy is initiated with latanoprost compared to timolol, when the cost price of latanoprost remains high.