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Objective:To observe the changes of the structure and visual function of the retina in patients with or without the ectopic inner foveal layers (EIFL) and to explore the factors influencing the recovery of visual function in patients with idiopathic epimacular membrane (IMEM).Methods:A retrospective clinical study. From March 2015 to June 2019, 90 patients with MEM who were diagnosed by Ophthalmic Center of the Second Hospital of Hebei Medical University were enrolled in the study. All patients were examined by best corrected visual acuity (BCVA) and frequency domain optical coherence scan. BCVA was recorded by Snellen vision table, and it was converted into the minimum resolution angle logarithm (logMAR) vision. Among 90 eyes, IMEM grade 2-4 was 68 (75.6%, 68/90), 18 (20.0%, 18/90), 4 (4.4%, 4/90), respectively. According to this, the grade 2 was set as group A, and the grade 3 and grade 4 were combined to group B. There was no significant difference in age ( t=0.015), sex composition ratio of patients between two groups ( χ2=0.060) and the average of central macular thickness (CMT) ( F=2.277) ( P=0.904, 0.809, 0.141). The difference of average logMAR and BCVA was statistically significant ( F=35.913, P=0.000). All patients underwent 25G pars plana three channel vitrectomy with simultaneous removal of epiretinal membrane and internal limiting membrane. BCVA, CMT and improvement of IMEM grading were observed at 1, 3, 6 and 12 months after operation. BCVA, EIFL thickness and CMT were compared before and after operation by single factor repeated variance analysis; Fisher exact probability method was used to compare the changes of the anatomical structure of the eyes in the two groups at 12 months after operation. Results:1, 3, 6, 12 months after operation, the average eyes of logMAR BCVA in group A were 0.50±0.13, 0.38±0.12, 0.27±0.12, 0.19±0.10. The patients in group B were 0.66±0.14, 0.60±0.13, 0.54±0.14, 0.52±0.14. CMT in group A were 364.82±81.29, 281.65±72.45, 228.55±55.34, 182.84±56.13 μm. The patients in group B were 455.88±69.60, 440.18±68.65, 383.76±65.38, 371.39±66.60 μm. The difference was statistically significant in the two groups (BCVA: F=37.913, 11.479, 24.250, 39.013; P=0.000, 0.002, 0.000, 0.000. CMT: F=10.987, 39.610, 55.789, 79.987; P=0.002, 0.000, 0.000, 0.000). In group A, IMEM was improved to 57 eyes of grade 1 on 12 months after operation. Among the 18 eyes in group B, IMEM was improved to 1 and 3 eyes in level 1 and level 2, respectively, and no improvement was found in 4 eyes in grade 4. The difference was statistically significant ( P=0.000) in the improvement of the number of eyes in the two groups. Conclusions:The patients with IMEM without EIFL have better visual prognosis and reversible anatomical changes. EIFL is an important factor affecting the visual function and anatomical structure recovery after operation.
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Background Cornea astigmatism can be effectively corrected by implanting Toric intraocular lens (IOL) during cataract surgery and therefore improve visual acuity of patients.However,the decentration and rotation position errors were inevitable sometime.What's the difference of effect of position errors on quality of image between spherical IOL and Toric IOL needs further research.Objective This study was to evaluate the optical performance and wavefront with rotation and decentration of Toric IOL.Methods Different decentration for SN60AT IOL(spherical IOL) and Toric IOL in Hwey-Lan Lion model eyes was set with the role as follows:decentration 0.25 mm to 0.75 mm in a 5°-interval from 0° to 90°.Furthermore,Toric IOL was rotated at 5° and 10°,respectively.Then the image performances of SN60AT IOL and Toric IOL at different decentration distances and rotated degrees were evaluated with modulation transfer function (MTF) and value of wavefront aberration under all conditions.Results At the centration,the MTF curves of spherical IOL and Toric IOL were similar under 3,4 and 5 mm pupil diameter at each spatial frequency.Under the condition of 4 mm pupil diameter,when the decentration was 0.25 mm,the MTF values of SN60AT IOL at 6 c/d and 12 c/d were 0.581 087 and 0.411 960,respectively.T3 IOL were 0.454 259 and 0.382 313,T4 IOL were 0.426 020 and 0.360 490,T5 IOL were 0.425 606 and 0.359 877.When the decentration was 0.50 mm,the MTF values of SN60AT at 6 c/d and 12 c/d were 0.573 073 and 0.412 787,respectively.T3 IOL were 0.450943 and 0.379481,T4 IOL were 0.423 153 and 0.356 664,T5 IOL were 0.422 881 and 0.356 230.When the decentration was 0.75 mm,the MTF values of SN60AT at 6 c/d and 12 c/d were 0.560 038 and 0.413 624,respectively.T3 IOL were 0.445 597 and 0.374 322,T4 IOL were 0.418 522 and 0.350 087,T5 IOL were 0.418 468 and 0.349 976.When the IOL decentralized along 0°,5°,10°,90°meridian line,the MTF values were almostly same.The root mean square (RMS) of spherical IOL and Toric IOL was increased when the IOL decentralized from 0 mm to 0.75 mm,with the most increasing level in coma aberration and slight increase in trefoil aberration.When the T4 IOL decentralized from centre to 0.75 mm,the coma increased from 0 to C(3,-1)-0.049 79 μm,C (3,1)-0.037 59 μm and the trefoil aberration increased from 0 to C (3,3) 0.005 72 μm,C (3,-3) 0.004 64 μm.With the increase of rotation degrees (from 5°to 10°) of Toric IOL,the MTF was worse at high spatial frequency.Toric IOL rotation caused the increase of astigmatism and residual astigmatism and spherical error,but not high order aberration.Conclusions The tolerance of Toric IOL to decentration is very close to the spherical IOL,and optical performance is only associated with the amount of decentration but not direction.The aberration caused by Toric IOL decentration is mainly coma.The rotation of Toric IOL causes astigmatism error but not high order aberrations.