Visual Field Preservation- How to Achieve Target IOP And Preserve Visual Fields In Glaucoma Patients

Target IOP is defined as the IOP level at which further glaucomatous optic neuropathy is unlikely to occur. It is a clinical estimate based on several factors. It depends on the severity of disease, the baseline untreated IOP level, the presence of risk factors for the development of glaucoma and its progression. Target IOP is not static but changes constantly depending on the signs of progression.

Every patient is different, therefore the target IOP should be individualized. The advantages of reaching this goal must be weighed against the risks of the treatment.

The UK Glaucoma Treatment Study (UKGTS) was the first randomized, masked, placebo-controlled trial of IOP lowering medical therapy in open angle glaucoma. This presentation will outline the major findings and implications for clinical practice and future clinical trial design. Compared to placebo, latanoprost reduced the risk of visual field progression from 25.6% at 2 years to 15.2%. The mean reduction in IOP was 3.8 +/- 4.0 mmHg in the latanoprost group (from a baseline of 19.6 +/- 4.6mmHg). The 20% reduction in IOP with latanoprost was associated with longer visual field preservation (hazard ratio =0.44). The risk of progression was double if an optic disc hemorrhage was present at baseline. In addition to demonstrating the efficacy of topical latanoprost, the study proved the feasibility of shorter duration trials using visual fields as the primary endpoint.

This presentation will focus on the secondary outcomes from the United Kingdom Glaucoma Treatment Study (UKGTS), highlighting the findings related to RNFL preservation and vision-related quality of life assessments. The mean difference in the rate of RNFL change between the latanoprost and placebo arms was 0.43 μm/year with synthesized spectral-domain OCT, which revealed a statistically significant difference in progression rates between two groups. Patient self-reported outcome measures on vision-related quality of life were insufficiently sensitive to serve as primary endpoints for capturing the latanoprost treatment effect in newly diagnosed early-stage glaucoma patients.