IBS Diagnosis Associated with Increased Risk of Glaucoma

Professor Mark McEvoy

The development of glaucoma may have associations with microbiome-host interactions, particularly in patients with irritable bowel syndrome (IBS), who have an abnormal gastrointestinal microbiome.

A recent study examined the potential associations between IBS and glaucoma and if IBS may be a risk factor in development of the neurodegenerative disease.

The team of investigators, led by Professor Mark McEvoy, Rural Health School, La Trobe University, found a diagnosis of IBS was associated with increased risk of glaucoma, in patients with IBS before or after 42 years old and still at the age of 50 years had a 6 times increase in the odds of developing glaucoma.

In addition, patients with IBS had 35% increased risk of being diagnosed with glaucoma, with similar risk rates of glaucoma surgery or medication initiation.

Methods

The team examined the risk of glaucoma diagnosis in both those with and without IBS diagnosis, who were part of the United Kingdom-based 1958 Birth Cohort (UKBC) or those who had data collected in the Danish National Registry of Patients (DNRP).

Participants in the UKBC were surveyed after birth during a single week in 1958, with self-reported follow-up at ages 42 and 50 years.

Moreover, the DNRP had hospital-based care records of both outpatient clinic and emergency department care, with Danish residents with a hospital discharge diagnosis of IBS from January 1995 - November 2013.

The team noted participants who met IBS criteria before or at the age of 42 and the age of 50 years were considered to have chronic IBS. On the other hand, participants were considered to have a case of incident glaucoma if they met criteria for glaucoma at age 50 years, but not at 42 years.

In addition, the DNRP identified glaucoma as physician diagnoses of primary open-angle glaucoma made in discharge diagnoses or hospital outpatient clinics, surgical procedures performed in hospitals, and first-time redemption of prescription for a medication used to treat glaucoma.

Results

A total of 9091 participants completed the UKBC at ages 42 and 50 years. In the study population, 775 participants (8.5%) reported IBS at or before the age of 42 years, while chronic IBS was identified in 162 participants (1.8%).

Data show the odds ratio of developing glaucoma between ages 42 and 50 in participants with chronic IBS was increased (OR 5.84; 95% CI, 2.26 - 15.13).

In the unadjusted model, investigators found those with IBS or before the age of 42 had over twice the odds of receiving a diagnosis of glaucoma between ages 42 and 50 (OR 2.15, 95% CI 0.86 - 4.67). However, investigators noted the result was not precise.

Further, the team found those with chronic IBS had six times the odds of developing glaucoma (OR 6.58; 95% CI, 2.00 - 16.89), in comparison to those without chronic IBS.

In the DNRP, investigators identified 62,451 persons with IBS and 625,410 matched general population cohort members.

In the data, glaucoma surgeries were identified for 69 IBS patients and 513 members of the comparison cohort and initiation of glaucoma medication was identified in 179 iBS patients and 1495 population cohort members.

Investigators found a hospital diagnosis of glaucoma was more frequent in patients in IBS than in the population cohort (HR 1.35; 95% CI, 1.16 - 1.56). In addition, IBS patients were at an increased risk for glaucoma surgery (HR 1.35; 95% CI, 1.06 - 1.70) and glaucoma medication use (HR 1.19; 95% CI, 1.03 - 1.38).

Conclusion

The team concluded with the hypothesis that patients with IBS are more likely to develop glaucoma may be due to host-microbiome interaction, or immune system dysregulation.

“Indeed, whether or not the current data are demonstrative of a causal link between IBS and glaucoma or rather a common causative pathway cannot be determined from this study and requires further research,” investigators wrote. “Both of these proposed mechanisms are (as it pertains to IBS pathology) bidirectional and so disentangling the mechanism will require further experimental research.”

The study, “Irritable bowel syndrome and risk of glaucoma: An analysis of two independent population‐based cohort studies,” was published online in UEG Journal.