Abstract:AIM:To investigate the distribution characteristics of retinal nerve fiber layer(RNFL)thickness and vessel density(VD)in macular area of eyes with high myopia(HM), using optical coherence tomography angiography(OCTA).
METHODS:Forty eyes in 20 patients diagnosed with HM, age 29.90±7.92 years old, with a spherical equivalent(SE)of -8.95±2.01 D, were recruited. The RNFL thickness and the VD of the superficial retinal capillary plexus(SCP), deep retinal capillary plexus, and choroidal capillary(CC)were measured by OCTA. Macular regions within a 6 mm diameter circle were divided into 9 subfields: the central subfield, and the pericentral and peripheral regions of superior, inferior, nasal, and temporal quadrants. The RNFL thickness of different subfields were compared, and their relationships with SE, axial length, and VD were analyzed.
RESULTS:In the pericentral region, the RNFL thickness of the superior quadrant was the lowest, whereas thickness was highest in the inferior quadrant(all P<0.05). In the peripheral region, the RNFL thickness of the temporal quadrant was the lowest(all P<0.05). A negative correlation was found between the RNFL thickness and SE(r=-0.356, P=0.024)in the peripheral superior subfield. The VD of SCP was positively correlated with RNFL thickness in the nasal and inferior quadrants of the pericentral region and in the superior, nasal, and inferior quadrants of the peripheral region(r=0.314, 0.408, 0.467, 0.655, and 0.737 respectively; all P<0.05), whereas the VD of CC was negatively correlated with RNFL thickness in the peripheral superior subfield(r=-0.356, P=0.024).
CONCLUSION:The RNFL of macular areas is not uniformly distributed in HM. As the SE increases, the RNFL thickness decreases in certain areas, which correlates with the VD of SCP and CC layers.