Effect of Myocilin Genetic Variants on Intraocular Pressure and Pressure Variation in Sitting and Supine Positions — Myoc Gene  

Glaucoma Clinical Trial

Official title: The Effect of Myocilin Genetic Variants on Intraocular Pressure and Blood Pressure Variation in Sitting and Supine Positions.

Status Completed

Clinical Trial Summary

The purpose of this study is to determine if one of the genes that can cause glaucoma, called myocilin, are associated with larger eye pressure and blood pressure changes in sitting and lying down positions without glaucoma drug treatment and with glaucoma drug treatment with a combination medication called Cosopt® (Merck & Co., Inc.).

Clinical Trial Description

Glaucoma is an important public health issue, and identifying new markers to improve treatment outcomes is a high priority. Progress in Mendelian genetic approaches has led to identifying 15 genes and 31 loci (http://www.ncbi.nlm.nih.gov/); however, since these monogenic forms of glaucoma are uncommon, other approaches are needed to identify genetic markers that contribute to common risk factors, such as elevated IOP, IOP fluctuation, and drug response variation.

It is well known that IOP varies over a 24-hour period,1-6 but the mechanisms that regulate this IOP rhythm are not yet fully known. Drance reported that 84% of normal eyes (N=320 eyes) had IOP fluctuations of less than 5 mmHg in contrast to only 6% of untreated glaucomatous eyes (N=138).7 Drance clearly recognized that IOP factors were more variable in eyes with glaucoma. Attention to this IOP fluctuation during glaucoma treatment is important because fluctuation leads to progression. The variation in IOP drug response profiles measured at selected times over a 24-hour period is related to the mechanism of action of these drugs, endogenous circadian rhythms, and glaucoma. We now have the molecular and genomic tools to identify potential genetic markers for these variable traits.

Advancing clinical research to the "translational" level is an important step to integrate our ever increasing knowledge base in genomics and proteinomics with clinical trials and clinical studies. Given the infrastructure at the University of Michigan with the strength in both glaucoma genetics and our resources in the clinic, we are well-positioned to conduct such translational research in glaucoma. Although it is known that myocilin (MYOC) mutations cause the phenotype of high pressure open-angle glaucoma (OAG), the effect of these MYOC mutations in "pre-symptomatic" subjects and patients with early OAG on IOP variation is not known. ;

Study Design

Allocation: Non-Randomized, Endpoint Classification: Pharmacokinetics Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Glaucoma

• NCT number: NCT00906087
• Study type: Interventional
• Source: University of Michigan
• Status: Completed
• Phase: Phase 4
• Start date: May 2009