Título

EVALUATION OF OCTA-MEASURED MACULAR DEEP CAPILLARY PLEXUS IN PATIENTS WITH CHIASMAL COMPRESSION AND CONTROLS.

Objetivo

To compare macular vessel density (mVD) of deep retinal layers (DRL) by optical coherence tomography angiography (OCTA) in eyes with band atrophy (BA) of optic nerve from chiasmal compression and normal controls.

Método

Prospective, cross-sectional study including 33 eyes from 26 patients with BA and temporal visual field defects (stable for at least 6 months) from previously treated suprasellar tumors and 35 eyes from 19 controls. All patients were scanned using MRI scanning to confirm chiasmal compression at the time of diagnosis and to document effective decompression after treatment. OCTA data were obtained using swept-source OCT (DRI OCT Triton Plus), with an acquisition speed of 100,000 A-scans/s in a 6x6 mm area centered on the fovea. The parafoveal vessel density within a 1.5 mm radius centered over the fovea (based on ETDRS grid) was obtained with the built-in tool for the deep retinal plexuses (in a slab from 15.6 μm to 70.2 μm beneath the interface of the inner plexiform layer and inner nuclear layer). Images were reviewed for correct centration and segmentation. The mVD of DRL was expressed as global average, and nasal and temporal sectors measurements.

Resultado

Compared to controls, BA eyes did not display a statistically significant difference when comparing the global means of mDV of DRL. However, smaller average DRL mDV was found in the nasal sector in BA eyes compared to controls (p=0.001). On the other hand, in the temporal sector, DRL mDV was increased in BA eyes compared to controls (p=0,021).

Conclusão

As previous studies have shown reduced OCTA-measured mDV in the superficial retinal layers in BA eyes, significant reduced mDV of DRL was found in nasal sectors, the more affected retina sector in chiasmal compression. Surprisingly, temporal sector mDV of DRL was increased in BA eyes when compared to controls. Image processing bias or compensatory mechanisms related to the nasal reduction of microvasculature are possible explanations of this finding.