Glaucoma is a major cause of eye disease throughout the world, leading to irreversible sight loss. Treatment for glaucoma seeks to reduce the pressure in the eye (so called intra ocular pressure), but this does not always halt progression of the disease. Some studies suggest a vascular cause, but evidence remains uncertain. Electronic records from general practice hold data on millions of patients, which are stored anonymously and used by researchers for clinical / patient benefit. Even though glaucoma is diagnosed by eye doctors in hospitals, these databases contain data on those treated for glaucoma, as ongoing medications for glaucoma are issued in primary care. We have previously used these records to show that those taking blood pressure lowering medications are at lower risk of glaucoma, suggesting that blood flow problems are related to developing glaucoma. This proposal seeks to examine the effect of erectile dysfunction in men, as a marker of poor blood flow / insufficiency (defined by intermittent prescribing for Viagra and similar drugs), on the development of glaucoma. Earlier limited evidence suggests that men taking Viagra are at increased risk of glaucoma, but this needs to be confirmed in longitudinal studies. This is important as this may inform new strategies to treat those with glaucoma, by increasing blood flow in addition to eye pressure lowering medications. We hope that further understanding the cause of glaucoma will help inform better treatments to avoid or halt sight-loss caused by glaucoma.
Background: Treatment for primary open angle glaucoma (OAG) involves pharmaceutical and/or surgical management of intra-ocular pressure (IOP), but this does not always halt disease progression. Limited evidence suggests that those receiving medications for vascular insufficiency are at increased risk of self-reported glaucoma diagnoses. However, confirmatory longitudinal evidence using a confirmed diagnosis in larger numbers is needed.
Aim: To examine whether vascular insufficiency in men (identified through treatment for erectile dysfunction) is prospectively associated with glaucoma diagnosis in a large English primary care database (Clinical Practice Research Datalink [CPRD] Gold and AURUM).
Study population: Cases are males with a glaucoma diagnosis and/or receiving ocular hypotensive medications, indicative of OAG, and controls (4 male controls to each case) matched for practice, and age within CPRD.
Data sources: In CPRD GOLD, 1,455,528 patients meet the eligibility criteria (male, aged >40 years, from 2005 to Jan 2023); of which 36,747 have a code for OAG. In CPRD AURUM, 5,580,934 patients meet the eligibility criteria (2005 to May 2022), with 137,127 OAG cases.
Study Design and Methods: Case-control study. Odds ratios (ORs) for oral treatment for erectile dysfunction, comparing those who have been diagnosed with OAG versus controls without a diagnosis, will be calculated by conditional logistic regression. Crude ORs will be calculated, with cases and controls matched for age, and practice, and then with further adjustment including sociodemographic factors and comorbidities, such as diabetes and associated complications, angina, myocardial infarction, asthma, and chronic obstructive pulmonary disease (COPD), and for number of drug types prescribed in the calendar year before case diagnosis as a measure of health care usage.
Benefit: Improving our understanding of the potential vascular aetiology of glaucoma may lead to novel medical interventions to improve blood flow, in addition to established IOP lowering strategies, to reduce progression and sight-loss caused by glaucoma
Incident open angle glaucoma diagnosis between 2005 and the most recent available data, defined by the presence of a diagnostic or prescription code related to OAG (see code lists in appendix).
Arturo Gonzalez-Izquierdo - Chief Investigator - University College London ( UCL )
Arturo Gonzalez-Izquierdo - Corresponding Applicant - University College London ( UCL )
Alicja Rudnicka - Collaborator - St George's, University of London
Christopher Owen - Collaborator - St George's, University of London
Muhammad Qummer ul Arfeen - Collaborator - University College London ( UCL )
Ruolan Fan - Collaborator - University College London ( UCL )
Patient Level Index of Multiple Deprivation