The Evaluation Of The Macular Function Of Pathological Myopic By MAIA Microperimetry

Objective This study was to assess the macular function of pathological myopia eyes using MAIA microperimetry, explore their function changes regulation, further analyze its associated factors.Methods 1. The frist step was to evaluate the sensitivity of MAIA microperimetry in macular function test and observe visual function changes regulation, its associated factors in these pathologic myopia eyes without maculopathy. 35 pathologic myopia patients(44 eyes) without any maculopathy(group A) and 15 low to moderate myopia patients(27 eyes) whose ages were matched as controls(group B) were included in this retrospective study. All patients took examinations of best corrected visual acuity(BCVA),refraction, axial length(AL). High-resolution optical coherence tomography(HD-OCT) was used to examine the retinal thickness in the central 20°of macular region. Then the mean light sensitivity(MS总) and fixation stability in the central 10°,fixation stability rate were recorded among all myopia eyes by using MAIA microperimetry. We then divided the macular central 10°regions into 5 parts. The mean light sensitivity of each part(MSs、MSt、MSn、MSi、MSm)were also determined. SPSS 17.0 statistical software was used to perform the t-test of two independent-samples to analyse the difference between MS总、MS of each section、fixation rate of central 2° and 4°. The chisquare test was chosen to compare the fixation stability rate. Pearson correlation was used to analyze the associated factors of MS.2. 52 patients of 91 pathological myopic eyes were enrolled in our second cross-sectional study.All patients underwent spherical equivalent(SE) and best corrected visual acuity(BCVA) examination by Early Treatment of Diabetic Retinopathy Study(ETDRS) charts and AL(axial length) measurement by IOL Master. Ophthalmoscope and Cirrus HD-OCT were used to evaluate macular microstructure changes, FFA was performed if necessary to diagnose macular diseases such as CNV(choroidal neovascularization)secondary to pathological myopia. Subjects were devided into two groups based on the existence of maculopathy(group A and B). According to the OCT and FFA, group B was further divided into choroidal neovascularization group,macular schisis group, acular hole group and mixed group.MS(mean sensitivity),fixation rate of central 2°and 4°, fixation stability pattern were determined by MAIA microperimetry( Center Vue,Padova,Italy) among all the participants in this study. The SPSS17.0 statistical software was adopted to perform the t-test of two independent-samples to analyse the difference of the two groups parameter. One-way ANOVA analysis was used to compare the differences of MS,P1,P2 in maculopathy subgroups. Correlation between MS, fixation rate and other parameters was performed in all patients, and the Pearman correlation coefficient was computed. Multiple linear regression models were also conducted. P<0.05 was considered to be a statistically significant difference.Results 1.In part one,compared with group B, the MS of central 10°and each part of central macular region was lower in group A(t=-2.413、-2.689、-2.063、-2.731、-2.018,P=0.019、0.009、0.043、0.008、0.048), except the inferior part(t=-1.400,P=0.166), the differences were statistically significant. The differences of 2°and 4°fixation rate, fixation stability rate were all not statistically significant( t=-1.740、-1.947,P=0.086 、 0.056, χ2=1.042, P>0.05). The relationships between MAIA microperimetry measurements and other parameters( SE, AL, BCVA, age) were analyzed by linear correlation analysis and expressed as the Pearson correction coefficient. Significant correlation was found between MS and age in all subjects and pathologic myopia eyes(r=-0.457, P=0.000; r=-0.594,P=0.000). MS significant decreased with the SE(r=-0.329,P=0.029). In some parts of central macular, the MS decreased as the retinal thickness become thinner(r上=0.420,P=0.019;r下=0.365,p=0.020;r鼻=0.381,p=0.013)2.In part two,the MS of two groups was(23.01±2.60,18.69±5.76)d B respectively, and there were statistically significance between two groups(t=4.028,P=0.000). The P1 of two groups was(79.32±25.32,71.38±31.14)%,the difference of P1 was statistically significant between the two groups(t=5.379,P=0.028),The P2 of two groups was(92.45±12.73,89.11±17.13)% The difference of P2 was not statistically significant between the two groups(t=7.056,P=0.345). The MS of the maculopathy subgroups were statistically significance( F=15.365, P<0.05); The P1 and P2 of the maculopathy subgroups were statistically significance( F=6.248 、 13.365, all P<0.05).When we investigated the correlation factors of MS among all pathological myopic participants, significant correlation was found with SE, AL, BCVA, P1, age(r=-0.373,-0.333,-0.452,0.644,0.414,all P<0.01). Both P1 and P2 had positive correlation with BCVA in group B(r=0.452,0.404; P=0.000,0.000). In the multiple linear regression analysis, BCVA was significantly(R2=0.458, F=9.916, P=0.000; R2=0.471, F=7.275,P=0.000) associated only with MS, no matter in all pathological myopic patients or pathological myopic patients complicated with maculopathy.Conclusions 1.Pathological myopia patients had decreased mean light sensitivity in the macular region, although without any maculopathy. The alteration of macular light sensitivity has regional differences,which should be paied more attention in function assessment of myopia.2.MAIA microperimetry is a sensitivite tool in testing macular function, it can realize localize and quantify of function evalution. The impact of spherical equivalent and age should be considered in the application of this instrument.3. The visual function deteriorated when pathological myopic complicated with maculopathy. Pathological myopia with macular hole have a more serious visual function impairment, followed by choroidal neovascularization. Macular schisis has relatively light injure.4.The fixation stability maintained normal when pathological myopia haven’t induced maculopathy. The fixation stability decreased when complicated with maculopathy. The fixation stability of pathologic myopia compalicated with macular hole and CNV seriously decreased.5.MS was the only predicting factor involved in determining the BCVA in pathological myopia, which means that patients with high MLS maybe ideal group for visual rehabilitation...