Visual Quality Analysis Of Low Moderate And High Astigmatism With Small Incision Lenticule Extraction(SMILE):Results Of A 3-month Follow-up

Objective Analyzing the 3-month follow-up results of postoperative residual astigmatism degree and visual quality of Low moderate and high astigmatism with small incision lenticule extraction(SMILE)by visual contrast sensitivity tester and OQAS double-pass system to evaluate the short-term clinical efficacy of astigmatism correction with SMILE.Methods A prospective case study was performed on 65 patients(127 eyes)who operated with SMILE at the Department of Ophthalmology,Jinling Hospital,Nanjing University,for the correction of myopic astigmatism from June to July.The patients were grouped according to the preoperative astigmatism degree.Group A included 51 eyes(astigmatism?0D),group B included 40 eyes(-1.00?-2.00D),group C included 36 eyes(-2.00D?-3.00D).All the patients were required to undergo a thorough eye examination before surgery and at 4 hours,1 week,1 month and 3 months aftersurgery.The preoperative routine examination included the assessment of uncorrected distance visual acuity(UCVA),best corrected distance visual acuity(BCVA),manifest and cycloplegic refraction,slit-lamp microscopy,dilated funduscopy,corneal thickness,pupil size,corneal topographic measurement,keratometry and non-contact tonometry.There were no significant differences within the three groups in age,BCVA,pupil size,corneal thickness and intraocular pressure(IOP).Re-examine visual acuity,spherical equivalent and astigmatism using automatic optometry unit under small pupil,visual contrast sensitivity(CS)under the condition of glare or not and objective scattering index(OSI),modulation transfer functions(MTF),MTF cutoff frequency(MTFcutoff),Strehl ratio(SR),OQAS values(Ovs)at contrasts of 100%,20%and 9%at 4 hours,1 week,1 month and 3 months after surgery,and patient satisfaction were also evaluated at 3 months postoperatively.Analyze the variation of visual acuity,spherical equivalent,astigmatism and visual quality at each follow-up postoperatively and compare the results within the three groups in the same time.Results(1)The results indicated that UCVA,spherical equivalent and astigmatism in pre-operation had a significant difference(P<0.05)compared with the postoperative at each time follow up,respectively.There was a tendency toward undercorrection on spherical equivalent and astigmatism with extended time,but the difference had no statistical significance(P>0.05).(2)The performance with which the group with preoperative astigmatism reached-2.00D?-3.00D gain lor 2 lines was superior to the performance with which the group with preoperative astigmatism within-2.00D.The frequency of eyes within ±0.5D of sphere in the 3 groups were 86.27%,85%,83.33%,and within ± 1.0D were 98.04%,97.5%,94.4%.And at the same time,the difference had no statistical significance in the frequency of eyes within ±0.5D of the cylindrical refractive error in the 3 groups.(3)With extended time,the contrast sensitivity was improved under the condition of glare or not at low and high spatial frequency(P<0.05),and it performed better at 3 months than 4 hours,1 week and 1 month after surgery.At 3 months,the values of group B were superior to other groups',but the difference had no statistical significance(P>0.05).(4)No significant difference were detected in each group in the MTFcutoff,OSI,SR and Ovs at any time point after surgery(P>0.05).And the MTFcutoff and OSI had no significant difference(P>0.05)in three groups at 3 month.(5)3 months after surgery,the patient satisfaction in each group had no statistical significance(P>0.05).And the main complaint were glare,poor nighttime vision and dry.Conclusion(1)SMILE could provide good clinical safety,efficacy,stability and relatively good predictability,visual quality in the correction of low moderate and high astigmatism.(2)At 3 months after operation,the average astigmatism had no significant difference in 3 groups,as well as OSI.the average OSI in all groups was a little deviated from the normal value range,so the scattering may be the main factor that influences the visual quality.(3)Compared with simple visual acuity testing,visual contrast sensitivity and OQAS could manifest visual quality better.Visual contrast sensitivity tended to subjectivity,while OQAS was objective.OQAS could quantificat visual quality parameters directly,carrying more retinal image information accurately.Cooperating with each other,combining with subjectivity and objectivity,they can provide a more complete and comprehensive analysis on visual quality.