The use of spectral-domain optical coherence tomography to evaluate the morphologic characteristics of paravascular retinal abnormalities in highly myopic eyes

Objective To evaluate the morphologic characteristics around the blood vessels of the retinal vascular arcade with spectral-domain optical coherence tomography (SD-OCT) in eyes with high myopia.Methods One eye of 177 patients with binocular high myopia (refractive error ≥-8.00 diopters or axial length ＞26.5 mm) was randomly selected to undergo detailed SD-OCT scans along the entire posterior vascular arcade.High myopic eyes with paravascular retinal abnormalities were classified as the positive group and those eyes without paravascular retinal abnormalities were considered as the negative group.A independent t test was used to compare the age of patients,refractive error and the axial length of myopic eyes in these 2 groups.A chi-square test was used to compare the cases of staphyloma in 2 groups.Results Among 177 high myopia patients,paravascular retinal abnormalities were detected in 108 patients (61.0％) by SD-OCT.The mean age of patients in the positive group was 59.3±6.2 years,the mean refractive error of the 108 eyes was-13.55±3.43 D,and mean axial length was 29.57±2.06 mm.The mean age of the 69 patients in the negative group was 34.8±13.1 years,the mean refractive error was-9.50±3.07 D,and mean axial length was 27.02±1.02 mm.The differences in the age of the patients (t=10.466),refractive error (t=7.454) and axial length (t=10.979) of myopic eyes between these two groups were statistically significant (P＜0.05).In the positive group,paravascular retinal cysts and microfolds were detected in all of the 108 eyes (100.0％),paravascular lamellar holes in 65 eyes (60.2％),paravascular retinoschisis in 53 eyes (49.1％),and tractional detachment of the retina in 1 eye (0.9％).All of the paravascular retinal abnormalities were located within staphyloma area of 2 to 3 PD from the optic disc.There were 101 eyes with staphyloma in the positive group and 48 eyes with staphyloma in the negative group.The difference between the 2 groups was statistically significant (x2=16.999,P＜0.05).Conclusion The present study illustrates that subtle but relatively common structural abnormalities occur in highly myopic eyes.Pathologic alterations in the vitreous cortex and staphyloma may be responsible for a variety of paravascular retina abnormalities.SD-OCT is necessary to diagnose and investigate paravascular retinal changes in highly myopic eyes. Key words: Myopia,degenerative;  Retina;  Retinal vessels;  Retinoschisis;  Tomography,optical coherence