| Purpose This study examined the profile of the choroidal thickness (CT) and photoreceptor layer thickness (PRLT) in healthy subjects with myopia, with an attempt to find the connection between change of CT and retinal degeneration.
Methods 66 study participants (66 eyes) were divided into three groups in terms of their refractive status: normal sight group, mild or moderate myopia group, high myopia group. The retinal thickness (RT), choroidal thickness (CT), retinal nerve fiber layer thickness (RNFLT), ganglion layer thickness (GLT) and photoreceptor layer thickness (PRLT) were measured by an ophthalmologist by employing spectral domain OCT (SD-OCT, spectralis, Heidelberg, Germany). The measurement area involved a region of 6 mm in diameter surrounding fovea. For each layer, the thickness was measured at 24 or 28 points. The mean thickness of all points was calculated.
Results As compared with group I, PRLT-pmr (perimacular region) and CT were significantly reduced (P<0.05) in group Ⅲ while no significant difference was found in RT, PRLT-cmp (central macular point), GLT and RNFLT between the two groups.Univariate linear regression analysis showed that PRLT was related with RE, RT, CT; CT was linearly related with RE, RT, PRLT.
Multivariate regression revealed that CT and PRLT were strongly intertwined.
Conclusions In high myopia subjects, PRLT-pmr reduced significantly. The reduced choroidal thickness was correlated with decreased retinal thickness and was intimately linked to the decreased PRLT-pmr. On the basis of NVU (neuron vascular unit) theory, improving the blood supply to retina may mitigate the retinopathy and reduce myopia related complications. |
