Ten-year trends in glaucoma drop prescribing and expenditure under Irish community drug schemes, 2015–2025

Abstract Background Glaucoma prescribing represents one of the largest components of ophthalmic drug expenditure, yet national prescribing trends in the Republic of Ireland have not been examined since 2003. This study evaluated changes in glaucoma prescribing, expenditure and opportunities for cost containment in the Republic of Ireland between 2015 and 2025. Methods National prescribing data for all glaucoma eye drops reimbursed under the General Medical Services, Drug Payment Scheme and Long-Term Illness schemes were obtained from the Primary Care Reimbursement Service. Costs were adjusted for inflation and population growth. Temporal trends were assessed using Kendall's tau, and a cheapest-alternative substitution model was used to estimate theoretical cost savings. Results Between 2015 and 2025, the PCRS reimbursed €139.9 million for 6.78 million glaucoma prescriptions. Prescriptions increased by 50.1% overall and 36.8% per capita ( τ = 0.891, 95% CI 0.683–1.099, p = 0.0002 ), while inflation-adjusted expenditure remained stable despite a 22.5% increase in nominal expenditure ( τ = −0.200, 95% CI −0.667–0.267, p = 0.436 ). Generic prescribing declined from 9.9% to 1.8% of prescriptions ( τ = −0.927, 95% CI −1.083– −0.771, p < 0.001), whereas preservative-free prescribing increased from 9.6% to 43.1% (τ = 1.000, p < 0.001). A cheapest-alternative substitution model identified €30.68 million (21.9%) in theoretical cost savings. Conclusions Glaucoma prescribing in Ireland increased substantially over the past decade while inflation-adjusted expenditure remained stable despite rising prescribing volumes. Although opportunities for cost savings narrowed over time, substantial theoretical savings remained. Greater use of cost-effective prescribing, supported by national formulary guidance, could further improve prescribing efficiency without compromising patient care.