Central Corneal Thickness in the Ocular Hypertension Treatment Study (OHTS).

Objective: Central corneal thickness influences intraocular pressure (IOP) measurement. We examined the central corneal thickness of subjects in the Ocular Hypertension Treatment Study (OHTS) and determined if central corneal thickness is related to race.

Design: Cross-sectional study.

Estimating correlation between multivariate longitudinal data in the presence of heterogeneity.

Background: Estimating correlation coefficients among outcomes is one of the most important analytical tasks in epidemiological and clinical research. Availability of multivariate longitudinal data presents a unique opportunity to assess joint evolution of outcomes over time. Bivariate linear mixed model (BLMM) provides a versatile tool with regard to assessing correlation.

Predicting Clinical Binary Outcome Using Multivariate Longitudinal Data: Application to Patients with Newly Diagnosed Primary Open-Angle Glaucoma.

Primary open angle glaucoma (POAG) is a chronic, progressive, irreversible, and potentially blinding optic neuropathy. The risk of blindness due to progressive visual field (VF) loss varies substantially from patient to patient. Early identification of those patients destined to rapid progressive visual loss is crucial to prevent further damage.

The effect of changes in intraocular pressure on the risk of primary open-angle glaucoma in patients with ocular hypertension: an application of latent class analysis.

Background: Primary open-angle glaucoma (POAG) is one of the leading causes of blindness in the United States and worldwide. While lowering intraocular pressure (IOP) has been proven to be effective in delaying or preventing the onset of POAG in many large-scale prospective studies, one of the recent hot topics in glaucoma research is the effect of IOP fluctuation (IOP lability) on the risk of developing POAG in treated and untreated subjects.

Method: In this paper, we analyzed data from the Ocular Hypertension Treatment Study (OHTS) and the European Glaucoma Prevention Study (EGPS) for subjects who had at least 2 IOP measurements after randomization prior to POAG diagnosis.

A Joint Model for Prognostic Effect of Biomarker Variability on Outcomes: long-term intraocular pressure (IOP) fluctuation on the risk of developing primary open-angle glaucoma (POAG).

Primary open-angle glaucoma (POAG) is among the leading causes of blindness in the United States and worldwide. While numerous prospective clinical trials have convincingly shown that elevated intraocular pressure (IOP) is a leading risk factor for the development of POAG, an increasingly debated issue in recent years is the effect of IOP fluctuation on the risk of developing POAG. In many applications, this question is addressed via a "naïve" two-step approach where some sample-based estimates (e.

Adjusting intraocular pressure for central corneal thickness does not improve prediction models for primary open-angle glaucoma.

Purpose: To determine if the accuracy of the baseline prediction model for the development of primary open-angle glaucoma (POAG) in patients with ocular hypertension can be improved by correcting intraocular pressure (IOP) for central corneal thickness (CCT).

Design: Reanalysis of the baseline prediction model for the development of POAG from the Ocular Hypertension Treatment Study (OHTS) substituting IOP adjusted for CCT using 5 different correction formulae for unadjusted IOP.

Participants: A total of 1433 of 1636 participants randomized to OHTS who had complete baseline data for factors in the prediction model: age, IOP, CCT, vertical cup-to-disc ratio (VCDR), and pattern standard deviation (PSD).

A joint-modeling approach to assess the impact of biomarker variability on the risk of developing clinical outcome.

In some clinical trials and epidemiologic studies, investigators are interested in knowing whether the variability of a biomarker is independently predictive of clinical outcomes. This question is often addressed via a naïve approach where a sample-based estimate (e.g.

Changes in central corneal thickness over time: the ocular hypertension treatment study.

Objective: To describe how much change, if any, occurs between central corneal thickness (CCT) measurements performed an average of 3.8 years apart in participants in the Ocular Hypertension Treatment Study (OHTS) and to identify clinical and demographic factors that are associated with changes in CCT, including baseline intraocular pressure, duration and class of ocular hypotensive medication, medical history, and systemic medication.

Design: Secondary analysis of data from a randomized clinical trial.

Comparison of initial intraocular pressure response with topical beta-adrenergic antagonists and prostaglandin analogues in African American and white individuals in the Ocular Hypertension Treatment Study.

Objective: To compare the intraocular pressure (IOP) responses of self-identified African American and white participants in the Ocular Hypertension Treatment Study to therapeutic trials of topical, nonselective beta-adrenergic antagonists or prostaglandin analogues.

Methods: Multivariate models that adjusted for baseline IOP and corneal thickness were used to estimate IOP response by race. Participants included 536 who were prescribed topical beta-adrenergic antagonists and 191 who were prescribed prostaglandin analogues, 25% of whom were African American.

Validated prediction model for the development of primary open-angle glaucoma in individuals with ocular hypertension.

Objective: To test the validity and generalizability of the Ocular Hypertension Treatment Study (OHTS) prediction model for the development of primary open-angle glaucoma (POAG) in a large independent sample of untreated ocular hypertensive individuals and to develop a quantitative calculator to estimate the 5-year risk that an individual with ocular hypertension will develop POAG.

Design: A prediction model was developed from the observation group of the OHTS and then tested on the placebo group of the European Glaucoma Prevention Study (EGPS) using a z statistic to compare hazard ratios, a c statistic for discrimination, and a calibration chi2 for systematic overestimation/underestimation of predicted risk. The 2 study samples were pooled to increase precision and generalizability of a 5-year predictive model for developing POAG.

Topical ocular hypotensive medication and lens opacification: evidence from the ocular hypertension treatment study.

Purpose: To determine whether topical ocular hypotensive medication is associated with refractive changes, visual symptoms, decreased visual function, or increased lens opacification.

Design: Multi-center clinical trial.

Methods: We compared the medication and observation groups of the Ocular Hypertension Treatment Study (OHTS) during 6.

Detection and prognostic significance of optic disc hemorrhages during the Ocular Hypertension Treatment Study.

Purpose: To compare the rates of detection of optic disc hemorrhages by clinical examination and by review of optic disc photographs at the Optic Disc Reading Center (ODRC), to assess the incidence of and the predictive factors for disc hemorrhages in the annual disc photographs of the Ocular Hypertension Treatment Study (OHTS), and to determine whether optic disc hemorrhages predict the development of primary open-angle glaucoma (POAG) in the OHTS.

Design: Cohort study.

Participants: Three thousand two hundred thirty-six eyes of 1618 participants.

Baseline topographic optic disc measurements are associated with the development of primary open-angle glaucoma: the Confocal Scanning Laser Ophthalmoscopy Ancillary Study to the Ocular Hypertension Treatment Study.

Objective: To determine whether baseline confocal scanning laser ophthalmoscopy (CSLO) optic disc topographic measurements are associated with the development of primary open-angle glaucoma (POAG) in individuals with ocular hypertension.

Methods: Eight hundred sixty-five eyes from 438 participants in the CSLO Ancillary Study to the Ocular Hypertension Treatment Study with good-quality baseline CSLO images were included in this study. Each baseline CSLO parameter was assessed in univariate and multivariate proportional hazards models to determine its association with the development of POAG.

Central corneal thickness and measured IOP response to topical ocular hypotensive medication in the Ocular Hypertension Treatment Study.

Purpose: To determine whether central corneal thickness (CCT) correlates with measured intraocular pressure (IOP) response to topical ocular hypotensive medication in the Ocular Hypertension Treatment Study (OHTS).

Design: Prospective randomized clinical trial.

Methods: Intraocular pressure measurements were performed by Goldmann applanation tonometry.

Baseline risk factors for the development of primary open-angle glaucoma in the Ocular Hypertension Treatment Study.

Purpose: Higher baseline pattern standard deviation (PSD) and larger vertical cup-to-disk ratio (VC/D) were factors in the predictive model for the development of primary open-angle glaucoma (POAG) in the Ocular Hypertension Treatment Study. Because early changes in PSD and VC/D may be indicative of early POAG damage, we repeated the prediction model excluding PSD and VC/D.

Design: Reanalysis of baseline factors for the development of POAG.

The Ocular Hypertension Treatment Study: topical medication delays or prevents primary open-angle glaucoma in African American individuals.

Background: The prevalence of glaucoma is higher in African American individuals than in white individuals.

Objective: To report the safety and efficacy of topical ocular hypotensive medication in delaying or preventing the onset of primary open-angle glaucoma (POAG) among African American participants in the Ocular Hypertension Treatment Study.

Methods: Eligibility criteria included age between 40 and 80 years, intraocular pressure between 24 and 32 mm Hg in one eye and between 21 and 32 mm Hg in the other eye, and no evidence of glaucomatous structural or functional damage by standard clinical measures.

The Ocular Hypertension Treatment Study: baseline factors that predict the onset of primary open-angle glaucoma.

Background: The Ocular Hypertension Treatment Study (OHTS) has shown that topical ocular hypotensive medication is effective in delaying or preventing the onset of primary open-angle glaucoma (POAG) in individuals with elevated intraocular pressure (ocular hypertension) and no evidence of glaucomatous damage.

Objective: To describe baseline demographic and clinical factors that predict which participants in the OHTS developed POAG.

Methods: Baseline demographic and clinical data were collected prior to randomization except for corneal thickness measurements, which were performed during follow-up.