Retinal and Choroidal Vascular Changes in Eyes with Pseudoexfoliation Syndrome: a Comparative Study Using Optical Coherence Tomography Angiography

Abstract

Background: Optical coherence tomography angiography allows a detailed evaluation of retinal and choroidal microvascular structures without the need for a contrast agent. Pseudoexfoliation syndrome is a condition that leads to anatomical and functional losses due to accumulation of degraded abnormal fibrillar material in the intraocular and extraocular tissues. Histopathological studies have shown that the accumulation of Pseudoexfoliation syndrome material in the vascular structures may play a role in different ocular pathologies such as retinal vein occlusion, iris hypoperfusion, anterior segment hypoxia, retinal arterial occlusion, and neovascular glaucoma. Aims: To evaluate and compare flow and vascular density in the retina and choroid in eyes with Pseudoexfoliation syndrome, fellow eyes without Pseudoexfoliation syndrome, and healthy eyes using optical coherence tomography angiography. Study Design: Case control study. Methods: The study included 35 eyes with Pseudoexfoliation syndrome of 35 Pseudoexfoliation syndrome patients, 32 fellow eyes without Pseudoexfoliation syndrome of 32 unilateral Pseudoexfoliation syndrome patients, and 35 eyes of healthy control subjects. Flow area and vascular density in the superficial capillary plexus and deep capillary plexus were measured by optical coherence tomography angiography as three separate parameters: total, parafoveal, and foveal. Choroidal thickness and foveal avascular zone area were measured for each patient. Results: There were significant differences between the Pseudoexfoliation syndrome eyes and control eyes in total, parafoveal, and foveal flow and vascular density in the superficial capillary plexus (p<0.05 for all), while there were no significant differences between these groups in any of the flow or vascular density values in the deep capillary plexus (p>0.05). None of the superficial capillary plexus and deep capillary plexus flow and vascular density values showed significant differences between Pseudoexfoliation syndrome eyes and non-Pseudoexfoliation syndrome fellow eyes or between the non-Pseudoexfoliation syndrome fellow eyes and control eyes (p>0.05). Choroidal thickness was significantly lower in Pseudoexfoliation syndrome eyes compared to control eyes. Foveal avascular zone area was significantly enlarged in Pseudoexfoliation syndrome eyes compared to control eyes in both the superficial and deep layers (p<0.05). Conclusion: Pseudoexfoliation syndrome eyes exhibit significant damage to the retinal and choroidal vascular structures.

The Importance of Signal Strength Index in Optical Coherence Tomography Angiography: A Study of Eyes with Pseudoexfoliation Syndrome

“…However, our results of the foveal vascular changes differ from those reported by Cinar et al 25 They found that the foveal VD in the superficial capillary plexus was significantly reduced in PXF eyes compared to controls, while we reported no difference between the groups after adjusting for IOP and SSI. 25 A possible reason for this discrepancy is that we used 3 × 3 mm macular scans, while Cinar et al used 6 × 6 mm macular scans. They also found that the superficial FAZ was significantly larger in the PXF cohort (0.31 vs 0.38 mm2, p = 0.01); however, they had not accounted for the SSI in their analysis.…”

“…There are 2 previous studies which have examined the macular parameters of OCTA scans in eyes with PXF and healthy controls. 9,25 Similar to our results, both have reported a reduction in the parafoveal VD of the superficial vascular plexus of PXF eyes. However, our results of the foveal vascular changes differ from those reported by Cinar et al 25 They found that the foveal VD in the superficial capillary plexus was significantly reduced in PXF eyes compared to controls, while we reported no difference between the groups after adjusting for IOP and SSI.…”

Cut-Off Values of Foveal Vascular Indices in Exfoliation Glaucoma

“…There was also damage to the retina and choroidal vascular structures, reduced choroidal thickness and enlarged FAZ area in eyes with XFS. 32 These changes in XFS becomes more noticeable as the disease progresses towards glaucoma and thereafter. Other ocular conditions that can increase retinal thickness may prevent diagnosis of co-existing glaucoma, also called “green disease”.…”

Does Pseudoexfoliation Syndrome Affect the Choroidal Response After Uneventful Phacoemulsification

“…In addition, optical coherence tomography angiography (OCTA) examinations of cases with PXS have been reported to show greater expansion, in both the superficial vascular plexus and the deep vascular plexus in the foveal avascular zone, compared with the non-PXS controls. 22 Sarrafpour et al 23 measured the subfoveal vessel diameters of eyes with PXS using SD-OCT and reported that the mean choroidal vessel diameter in the subfoveal area was 13 µm smaller in unilateral PXS cases than in the contralateral eye. These findings demonstrate the effects of the degeneration caused by PXM in the retinal and choroidal vessels.…”