Is Glaucoma Hereditary? Know Your Risk

Is Glaucoma Hereditary?

Glaucoma is a progressive optic neuropathy characterized by loss of peripheral vision in characteristic patterns.

The disease is caused by increased eye pressure which inflicts irreparable damage on the optic nerve.

Increases in eye pressure occur when the eyes can’t drain enough aqueous humor from their drainage canals, leading to increased aqueous humor build-up in the cornea and retina.

Genetic studies have identified mutations associated with glaucoma in various families.

Congenital

Congenital hereditary glaucoma (CHG), while uncommon, can result in significant vision loss.

CHG typically presents in early childhood due to mutations of the optineurin gene (OPTN).

Such mutations cause sudden increases in pressure within the eye that damage optic nerves.

Genetic studies on glaucoma have identified several genes as being associated with the condition. This includes CYP1B1, MYOC, FOXC1 and TEK.

The ANZRAG study is an Australasian registry designed to identify genes linked to glaucoma; participants include patients from across Australia ranging from those diagnosed with PCG and JOAG.

Glaucoma research is invaluable as its effects can have a lifelong effect on those affected.

This is especially true for children who rely on visual aids, often becoming targets of bullying due to this dependency.

These children can suffer a decrease in confidence and self-esteem; schoolwork may become difficult; social interactions could even suffer as a result.

Molecular diagnosis can offer many advantages to these individuals and their families.

It can assist with an accurate clinical diagnosis, enable individuals to be properly advised about their mode of inheritance, as well as inform future research into potential treatments such as gene therapy that has shown promise against other neurological disorders.

Primary

Children and early-onset glaucoma is an often debilitating disease that can result in permanent vision loss, but early diagnosis and appropriate treatment can significantly improve outcomes for these patients.

Genetic testing can also identify people at greater risk of this condition; its results help researchers gain insight into why glaucoma develops and how best to avoid it in future generations.

Primary glaucoma is caused by isolated abnormalities to structures responsible for maintaining normal IOP, such as trabecula dysgenesis or angle dysgenesis, leading to decreased outflow from the eye.

This problem often stems from structural defects of the trabecular meshwork abnormalities on the cornea, or structural problems with either of them.

Changes to IOP can result in visual field loss, pain, and other symptoms; sometimes this elevation in IOP may even be the result of systemic diseases like fibromyalgia, inflammatory uveitis, Behcet’s disease pars planitis, or sarcoidosis.

Multiple studies have reported the highest diagnostic yield among patients with glaucoma caused by nonacquired ocular anomalies.

One such study identified variants in FOXC1 and PITX2 genes as common causes for their patients’ ARS; another discovered that clinical diagnosis of glaucoma associated with nonacquired anomalies was accurate for 64% of the probands.

Secondary

Secondary Glaucomas typically result from structural abnormalities. Primary Angle-Closure Glaucoma (PACG), however, can be caused by an iridotrabecular contact that could either be appositional or synechial and causes obstruction to drainage angles and raised IOP; alternatively, it could also result from obstruction to outflow due to various reasons including:

Glaucoma may also result from abnormal genetic mutations. One study reported that 10.4% of individuals diagnosed with glaucoma saw their clinical diagnosis alter after receiving genetic results, providing family members with accurate guidance regarding inheritance patterns as well as personalized therapy solutions.

PDS (Pigment Dispersion Syndrome) is another hereditary form of glaucoma that typically manifests itself among Caucasian myopic patients.

A rubbing action between lens zonules and the posterior surface of the iris causes pigment granules to release into the eye, increasing outflow resistance by blocking aqueous humor outflow, leading to elevated intraocular pressure (IOP) and typically glaucomatous optic neuropathy symptoms – and often manifesting in reverse pupillary block configuration of the iris – making PDS an essential indicator for early diagnosis to avoid developing primary open-angle glaucoma.

Symptomatic

Long-term management of childhood glaucoma and its possible progression to irreversible visual loss may hurt quality of life (QoL).

Unfortunately, its full extent remains unknown; therefore this study sought to assess QoL in adults living with childhood glaucoma using patient-reported outcome measures (PROMs).

Participants were recruited from the Australian and New Zealand Registry of Advanced Glaucoma (ANZRAG) using nonprobability convenience sampling.

ANZRAG is an ongoing observational study designed to identify genetic links with glaucoma; all participants undergo genetic testing.

All Australian residents regardless of subtype were included, regardless of age; English was spoken during interviews.

271 children living with childhood glaucoma were interviewed regarding their experiences of the condition.

Most participants reported being symptomatic and taking medications to lower their intraocular pressure (IOP).

Others had cataracts, strabismus, or high myopia which required them to wear corrective lenses or even use canes for mobility purposes.

The results of this qualitative research demonstrated that individuals diagnosed with glaucoma experienced psychological distress, particularly concerning their future vision.

Additionally, they often became aware of its effect on others and felt unable to fulfill their roles as parents due to visual restrictions caused by ocular limitations.

They also worried about inherence leading to family planning concerns and inheritance concerns for future generations.