Glaucoma Examination in the Amish of Holmes County, Ohio

Abstract

Purpose : Despite extensive efforts to understand the genetic and environmental risk factors for glaucoma, we still lack a comprehensive, clinically useful risk profile. We have previously established a significant presence of glaucoma in the Amish in Holmes County OH. Our goal is to determine the prevalent type(s) of glaucoma in this population and begin assessing for novel genetic and environmental risk factors. The Amish in Holmes County, Ohio, are a unique population that provides a truly unmatched opportunity to study complex diseases on a more homogeneous genetic and environmental background.

Methods : Amish subjects identified through an existing research infrastructure were screened by a glaucoma specialist via comprehensive ophthalmic examination wherein glaucoma type and severity were determined. Extensive familial structure and relatedness data was reviewed. Lifestyle questionnaires were used to assess environmental exposures and habits. Blood drawn from subjects will be utilized for comprehensive genetic analysis.

Results : Recruitment thus far has predominantly targeted Amish who previously self-reported a prior glaucoma diagnosis as well as their close family members. To date, 53 Amish subjects have undergone comprehensive ocular examination with glaucoma screening. Of those, 36 have primary open angle glaucoma (POAG), ranging in severity from suspect to severe. Four individuals have pigmentary glaucoma and one has chronic angle-closure glaucoma. Positive predictive value between self-reported glaucoma and glaucoma diagnosis is 100%, while negative predictive value is 45%. Lifestyle assessment has confirmed a more homogeneous and reduced exposure to typical western society behaviors such as alcohol consumption and smoking. An additional 100+ subjects in this population will be recruited, many of whom show familial clustering of glaucoma.

Conclusions : We determined that heritable glaucoma is present in the Amish of Holmes County, Ohio and is predominately POAG. Accessing an extensive and largely related Amish population to understand risk factors of heritable adult-onset glaucoma has not previously been reported, and offers the opportunity to identify novel genetic and environmental risk factors for this high impact, complex disease. The Amish are ideal for these studies due to a relatively homogeneous genetic background and a less diverse yet shared environmental exposure profile.

This is a 2020 ARVO Annual Meeting abstract.