Pseudoexfoliation deposits can accumulate on the walls of arteries and veins, disrupting microvascular blood flow in the eye and harming the retina. Photo: Aaron Bronner, OD. Click image to enlarge.

Pseudoexfoliation syndrome (PXS) is commonly associated with secondary glaucoma due to increased intraocular pressure from abnormal protein deposits in the anterior segment. While it typically presents unilaterally, it may become bilateral over time in some individuals. Beyond its ocular implications, pseudoexfoliation syndrome has systemic associations such as cardiovascular and cerebrovascular diseases, including Alzheimer-like dementia. Given its effects on vascular health, researchers in Korea conducted a retrospective study of the unaffected fellow eyes of patients with unilateral pseudoexfoliation syndrome to compare macular and optic disc vascular parameters against controls using OCT angiography. In a recent BMC Ophthalmology paper, they reported several significant differences among parameters, indicating potential subclinical pseudoexfoliation syndrome in “unaffected” fellow eyes.

The researchers analyzed the medical records of 61 eyes (30 unaffected fellow eyes and 31 control eyes). They used OCTA to measure vessel density (VD), perfusion density (PD) and foveal avascular zone (FAZ)-related parameters of the superficial capillary plexus in the circumpapillary and macular area, and VD and PD of the deep capillary plexus in the macular area. Age, sex and axial length adjustments were made. Both study groups had no statistically significant differences in sex ratio or mean age, central corneal thickness measurements, refractive errors, intraocular pressures or axial length.

The researchers reported that in the circumpapillary area, the inferior VD and PD in the inner zone, and the average, temporal, inferior and nasal VD and PD in the outer zone were significantly reduced in unaffected fellow eyes. However, the two groups demonstrated similar circumpapillary retinal nerve fiber layer thicknesses.

In the macular superficial capillary plexus, the researchers found that the VDs were significantly lower in all sectors in the inner area and in the outer zones. PDs were also significantly lower in all sectors, except for the nasal sector of the outer zone. The FAZ circularity was significantly lower in unaffected eyes. The macular ganglion cell inner plexiform layer thicknesses were similar between the two groups.

“These microvasculature differences may support subclinical pseudoexfoliation syndrome features in the unaffected fellow eyes,” the researchers concluded in their BMC Ophthalmology study. “Our study demonstrates the importance of appropriate ophthalmic examination and follow-up of both eyes of subjects with unilateral pseudoexfoliation syndrome, even if the pseudoexfoliation-free fellow eyes have normal IOP.”