Paravascular abnormalities observed by spectral domain optical coherence tomography are risk factors for retinoschisis in eyes with high myopia.

Abstract

To investigate the retinal features and distribution of paravascular abnormalities (PVAs) andtheir relationship with retinoschisis in eyes with high myopia. One hundred and fifty-two eyes of88 patients with high myopia [refractive error greater than -6dioptres (D) or axial length (AL) ≥26.5mm] who had undergone comprehensive ophthalmic examinations were evaluated in this cross-sectional study. Multiple optical coherence tomography (OCT) scans were performed to study the microstructural alterations adjacent to the retinal vascular arcades and the entire macular area. The presence and distribution patterns of various PVAs, retinoschisis and the association between these parameters were analysed. Of the 152 highly myopic eyes, PVAs were detected by OCT in 126 eyes (82.9%), including paravascular microfolds in all 126 eyes, paravascular cysts in 109 eyes (71.7%) and paravascular lamellar holes in 44 eyes (28.9%). All three types of PVAs were observed more frequently along the temporal vascular arcades than along the nasal vascular arcades (p<0.005). Seventy-eight eyes (51.3%) were identified with retinoschisis at retinal vascular arcades, most frequently in the inner plexiform layer (IPL) and along temporal arcades. Eyes with all three types of PVAs (microfolds, cysts and lamellar holes) had the highest incidence of retinoschisis at vascular arcades (p<0.001). Multivariate analysis indicated that age, the AL, presence of paravascular microfolds and cysts, and simultaneously existence of all three types of PVAs were associated with an increased risk for retinoschisis at vascular arcades. Macular retinoschisis was detected in 25 eyes (19.8%) and presented with splitting of the outer retina in all cases. All seven eyes with entire macular area retinoschisis (S4 grade) were accompanied by retinoschisis at vascular arcades within multiple layers, including outer retinoschisis, IPL schisis and inner limiting membrane (ILM) detachment. Our findings indicated that all three types of PVAs and different types of retinoschisis were most frequently observed along the temporal vascular arcades. Eyes with paravascular microfolds and cysts, and those with all three paravascular lesions may in risk of developing retinoschisis at vascular arcades.