Effects of myopia on different areas and layers of the macula: a fourier-domain optical coherence tomography study of a chinese cohort

Abstract

BackgroundTo explore the changes in thickness in different areas and layers of the macula under different refractive conditions.MethodsConsecutive participants were enrolled in the study. Optical coherence tomography (OCT) images were obtained using a spectral-domain system. We studied the relationships of the full, inner and outer retinal thicknesses of the fovea, parafovea and perifovea relative to the spherical equivalent (SE) and axial length (AL).ResultsWe included 107 eyes; the analysis revealed that the men had thicker foveas (man vs women: 236.70 ± 18.97 μm vs 247.25 ± 16.70 μm P = 0.002) and inner parafoveas (man vs women: 128.35 ± 8.80 μm vs 122.78 ± 6.75 μm P < 0.001) than the women had. Full foveal thickness was not correlated with AL or SE (all P > 0.05), whereas the full para- and perifoveal thicknesses had significant negative correlations with AL (r = –0.243 P = 0.006 and r = –0.446 P < 0.001, for para- and peri- respectively) and positive correlations with SE (r = 0.346 P < 0.001 and r = 0.464 P < 0.001, for para- and peri- respectively). Regarding the layers, the thickness of the inner layer of the fovea increased with the degree of myopia. The average inner and outer layer thicknesses of the para- and perifovea decreased with the degree of myopia (with the SE para, b = 0.307, peri b = 0.457; with the AL para, b = –0.266, peri b = –0.454),with the perifoveal thicknesses decreasing more rapidly.ConclusionsMacular thickness changes with the degree of myopia; however, the different areas and different layers change in different manners.Electronic supplementary materialThe online version of this article (doi:10.1186/s12886-015-0080-5) contains supplementary material, which is available to authorized users.

Macular Microvasculature in High Myopia without Pathologic Changes: An Optical Coherence Tomography Angiography Study

“…inal thickness was increased, but showed no significance. This finding was similar to that of a previous study [14]. In other studies, however, the increased foveal retinal thickness was significant [4,6,7,[11][12][13]16,[22][23][24], which could be due to the foveal elevation secondary to the mechanical stretching and pararetinal thinning in myopic eyes and the foveal retinal pigment epithelium's high permeability [6,10,[12][13][14]16,23,24].…”

“…In other studies, however, the increased foveal retinal thickness was significant [4,6,7,[11][12][13]16,[22][23][24], which could be due to the foveal elevation secondary to the mechanical stretching and pararetinal thinning in myopic eyes and the foveal retinal pigment epithelium's high permeability [6,10,[12][13][14]16,23,24]. Additionally, the absence of large vessels and optic fibers make the peripheral retina less resistant to stretching, while the foveal thickness is preserved [4,7,13,14,16]. In addition, the parafoveal retinal thickness was positively correlated with the SCP VD in our study, and the correlation was the strongest in the nasal and inferior sectors.…”

“…Myopia is the leading cause of vision impairment, affecting more than 1.4 billion people worldwide [1][2][3][4][5][6][7][8][9][10]. Its prevalence has been increasing in Asia [1][2][3]5,7,[9][10][11][12][13][14]. Myopia with a refractive error >-6 diopters (D) or an axial length >26 mm is considered pathologic.…”

Retinal Microvasculature Alteration in High Myopia

“…Furthermore, the C5 annular zone (1.88-2.2 mm) had the highest AUC when compared with other zones, which may be a result of increased thinning in the parafoveal area versus the foveal area in highly myopic eyes. 32 As expected, the combined microvessel density of the superficial and deep retinal layers returned the highest AUC value. Therefore, this measurement could be used as an early macular retinopathy surrogate endpoint in clinical trials involving myopic patients.…”

“…These densities were significantly lower in highly myopic subjects compared to controls, suggesting that the retinal microvasculature of highly myopic eyes is affected by diffuse alterations rather than isolated local changes. Decreased retinal thickness 32 and inner retinal layer dysfunction 33 have been linked to high myopia. A decline in microvessel density may be caused by reduced blood supply demands due to the retinal degeneration occurring in highly myopic eyes.…”