Relationship between macular retinal thickness and visual acuity in high myopia / 中华实验眼科杂志

ABSTRACT

Background It is well known that the diminution of visual acuity appears before notable complications in some high myopic eyes.However,whether the impaired vision is associated with the change of retinal thickness at macula area is still under investigation.Objective This study was to investigate the relationship of macular retinal thickness with the change of visual acuity in high myopic eyes.Methods A consecutive caseobservational study was performed.Two hundred and forty-five eyes of 132 patients with the diopter of-6.00～-20.00 D were enrolled in this study during the January 2011 to January 2012 in Beijing Tongren Eye Center.All of the patients received the measurement of retinal thickness with Fourier Domain Optical Coherence Tomography (FDOCT),and the scan mode was MM6.The eyes were divided into the corrected vision ≥0.9 group and the corrected vision ≤0.8 group.In addition,the eyes were assigned to the non-posterior staphyloma group,posterior staphyloma Ⅰ group (macular symmetry) and posterior staphyloma Ⅱ group (macular gradient).The retinal thicknesses in different quadrants at the macular zone were measured and calculated by OCT software.Results The demography was matched in different groups.Corrected visual acuity was significantly increased in the corrected vision ≥ 0.9 group than that in the corrected vision ≤0.8 group (1.02±0.16 vs.0.62±0.08) (t=3.233,P=0.001).Retinal thickness value at fovea was (256.28±13.19) μm in the corrected vision ≥0.9 group,and that in the corrected vision ≤0.8 group was (231.17 ± 10.96) μm,with a significant difference between the two groups (t =2.134,P =0.031).The corrected visual acuity was 1.00±0.27,0.78±0.21 and 0.90±0.13 in the non-posterior staphyloma group,posterior staphyloma Ⅰ group and posterior staphyloma Ⅱ group,respectively,showing significant difference among the three groups (F=15.760,P=0.015),and the corrected visual acuity of the non-posterior staphyloma group and posterior staphyloma Ⅱ group were significantly higher than that of posterior staphyloma Ⅰ group (q =16.131,P =0.006 ; q =-10.831,P=0.008).A significant difference also was seen in the mean retinal thickness among the three groups (F=2.316,P =0.025).The mean retinal thickness in the posterior staphyloma Ⅰ group was (234.21 ± 15.69) μm,which was significantly smaller than (252.25± 15.31) μm of the posterior staphyloma Ⅱ group (q =12.977,P =0.023).There were no significant difference in the retinal thickness at para-fovea area among the three groups (F=0.318,P =0.078).However,significant difference was found at peri-fovea area in different groups (F=1.925,P =0.013).The mean retinal thicknesses at peri-fovea area was (273.26 ± 16.37) μm in the posterior staphyloma Ⅱ group and was significantly smaller than (289.11 ± 19.30) μm of the posterior staphyloma Ⅰ group and (290.33 ± 17.12) μm of the non-posterior staphyloma group (q =-8.305,P =0.023 ; q =-7.011,P =0.012).Conclusions The retinal thickness at fovea is associated with the corrected visual acuity in high myopic eyes.The thinning of retinal thickness at the vertex of posterior staphyloma is one of causes of visual function impairment.