Application Of Spectral-domain Optical Coherence Tomography In The Measurement Of Macular Outer Nuclear Layer Of Myopia

Objective: To quantitatively analyze the difference in retinal thickness of macular outer nuclear layer(ONL)between myopia patients and normal subjects by spectral-domain optical coherence tomography(SD-OCT).Methods: 92 cases(92 eyes)were divided into four groups according to their spherical equivalent(SE).There were 17 cases(17 eyes)in normal control group(0.50D?SE?0.50D),26 cases(26 eyes)in low myopia group(-3.00D?SE<-0.50D),24cases(24 eyes)in medium myopia group(-6.00D?SE<-3.00D)and 25 cases(25 eyes)in high myopia group(SE<-6.00D).The macular retina was scanned by the posterior pole asymmetry analysis mode of Heidelberg Spectralis SD-OCT and divided into 9 areas according to Early Treatment Diabetic Retinopathy Study.Quantitative analysis was performed to compare the difference in retinal thickness of macular ONL in each area between the four groups.Results: The ONL thickness in the central area of the macular retina was significantly higher than other areas(all P < 0.001).Every area of the ONL thickness in the inner ring of the macular retina was significantly higher than in the corresponding area of the outer ring(all P < 0.001).In the outer ring of the macular retina,the difference of ONL thickness was statistically significant between random two areas(outer ring superior and outer ring nasal,P < 0.05;outer ring superior and outer ring inferior,outer ring superior and outer ring temporal,outer ring nasal and outer ring inferior,outer ring inferior and outer ring temporal,P < 0.001),except outer ring nasal and outer ring temporal(P=0.856).In the outer ring of the macular retina,the ONL thickness in outer ring superior was the thickest and in outer ring inferior was the thinnest.In the inner ring of the macular retina,the difference of ONL thickness was statistically significant between random two areas(inner ring superior and inner ring nasal,inner ring superior and inner ring inferior,inner ring nasal and inner ring temporal,P < 0.05;inner ring nasal and inner ring inferior,inner ring inferior and inner ring temporal,P < 0.001),except inner ring superior and inner ring temporal(P=0.710).In the inner ring of the macular retina,the ONL thickness in inner ring nasal was the thickest and in inner ring inferior was the thinnest.The ONL thickness in central,outer ring nasal and inner ring nasal area of the macular retina had positive correlations with SE(r=0.3071,0.3217,0.3721,P<0.05).In other regions,no correlations were found(P >0.05).The ONL thickness in outer ring nasal,inner ring nasal and inner ring inferior area of the macular retina had negative correlations with axial length(r=-0.3919,-0.3686,-0.3145,P<0.05).In other regions,no correlations were found(P >0.05).Comparing the ONL thickness in macular retina of normal control group and low myopia group,the ONL thickness in outer ring nasal was significantly higher in normal control group than in low myopia group(P <0.05).In other regions,no difference in the ONL thickness was found(P >0.05).Comparing the ONL thickness in macular retina of normal control group and medium myopia group,the ONL thickness in outer ring nasal,inner ring nasal and outer ring superior area was significantly higher in normal control group than in medium myopia group(P <0.05).In other regions,no difference in the ONL thickness was found(P >0.05).Comparing the ONL thickness in macular retina of normal control group and high myopia group,the ONL thickness in outer ring nasal,inner ring nasal,inner ring inferior and central area was significantly higher in normal control group than in high myopia group(P <0.05).In other regions,no difference in the ONL thickness was found(P >0.05).Comparing the ONL thickness in macular retina of low myopia group and medium myopia group,no difference in the ONL thickness was found(P >0.05).Comparing the ONL thickness in macular retina of low myopia group and high myopia group,the ONL thickness in inner ring nasal area was significantly higher in low myopia group than in high myopia group(P <0.05).In other regions,no difference in the ONL thickness was found(P >0.05).Comparing the ONL thickness in macular retina of medium myopia group and high myopia group,no difference in the ONL thickness was found(P >0.05).Conclusion: 1.There is a regional characteristic of the ONL thickness.2.With an increase in SE and axial length,the ONL thickness in nasal and area of the macular retina became thinner.3.With an increase in SE and axial length,the ONL thickness in the outer ring nasal of the macular retina was the first to be affected and became thinner,and gradually affected the inner ring nasal and central area.