Patients who are frequent drinkers or social wallflowers may be more inclined to have thinner areas of their inner retina, a study in Ophthalmology reports. The large UK-cohort investigation compared the macular retinal nerve fiber layer, ganglion cell complex and ganglion cell–inner plexiform layer (GC-IPL) to look for retinal thinning trends and other novel lifestyle and genetic associations that could help in the diagnosis of glaucoma.

The study included data from 42,044 participants in the UK Biobank, a large-scale multi-site cohort study. The researchers noted the average age of participants was 56, and 53% of the subjects were women.   

The investigation used spectral-domain OCT macular imaging and corneal compensated intraocular pressure (IOPcc) measurements to analyze and compare the inner retinal structures. The study considered several factors such as age, sex, ethnicity, height, BMI, smoking status, alcohol intake, education level, diabetes status, spherical equivalent and IOPcc.

In addition to confirming previously reported associations with thinner inner retinal thickness (older age, male sex, higher BMI and diabetes), researchers identified several unique, independent associations:

• Thinner inner retinas were associated with frequent alcohol intake and most significant in the GC-IPL: -0.46μm for daily or almost daily alcohol consumption compared with special occasion or non-drinkers.
• Greater social deprivation was also most significant when measuring GC-IPL changes: -0.28μm for the most deprived quartile compared with the least deprived.
• Lower education was most significant for the macular retinal nerve fiber layer measurement: -0.36μm for lower education levels compared with those who had a degree.
• Patients who were of a non-white ethnicity had thinner macular retinal nerve fiber layers, an average of -1.65μm, compared with subjects who were black or white.

Additionally, the study found IOPcc was most significantly associated with GC-IPL (-0.04μm/mmHg), but not macular retinal nerve fiber layer. The researchers also noted more patients had variable GC-IPL (11%) than ganglion cell complex (6%) or macular retinal nerve fiber layer (7%).

“The novel associations we identified may be important to take into account when using inner retinal parameters as a diagnostic tool,” the researchers wrote in their paper. Associations were generally strongest with GC-IPL, particularly for IOP, they noted. This suggests the GC-IPL may be the superior inner retinal biomarker for macular pathophysiological processes, and especially for glaucoma, the investigators added.