The Studies On Optical Quality And Analysis Of The Cause Of Dysphotopsia After Implantable Contact Lens Surgery

Part oneComparison of the early postoperative visual quality between implantable contact lens(ICL)and small-incision lenticule extraction(SMILE)for high myopiaPurpose: To objectively compare the optical quality and intraocular scattering between SMILE(small-incision lenticule extraction)and ICL(implantable contact lens)for severe myopia.Methods: This retrospective study covered 36 eyes of 18 consecutive patients undergoing SMILE(mean age ± standard deviation,24.353 ± 4.568 years),and 36 age-matched eyes of 18 patients undergoing ICL(age,22.733 ± 4.527 years).The postoperative values of MTF cut off(Modulation tansfer function cut off),SR(Strehl ratio),and OSI(objective scattering index),were quantitatively assessed using an Optical Quality Analysis System?.These postoperative variables of the two groups were compared.Results: On postoperative day 7,the UDVA values of the SMILE group were found to be better than those of the ICL group(P = 0.042),no significant differences in BSCVA or spherical equivalent were observed at other postoperative points in time between ICL and SMILE groups(P>0.05).No significant difference in MTF cutoff was found between the ICL and SMILE groups at any point in time(P>0.05).No significant difference in SR was found between the ICL and SMILE groups at any point in time(P>0.05).OSI was significantly lower than in the SMILE group on days 7(P = 0.002)and 20(P = 0.031),but there was no significant differences on day 40(P > 0.05);Part twoAnalysis of the cause of dysphotopsia and the correlation with Zernike polynomials' aberrations after Implantable contact Lens surgeryObjective Analysis of the cause of dysphotopsia and the correlation with Zernike polynomials' aberrations after Implantable Collamer Lens(ICL)surgery.Methods The Zernike polynomials' aberrations of 44 eyes of 22 patients with mesopic pupil and mydriasis after ICL surgery were investigated by using Nidek OPD-san III.Dysphotopsia was divided into 4 levels and rated the score 0 to 3.Then the correlation between Zernike polynomials and dysphotopsia was determined.Results The pupil's diameter of all eyes was 5.75±0.75 mm at dark condition.There were 33 eyes(75%)without dysphotopsia,10 eyes(23%)waere slight dysphotopsia,1 eye(2%)was moderate dysphotopsia and No eye was serious dysphotopsia.The dysphotopsia was positive correlation with Astignatism(r=0.314?r=0.313,P<0.05),Defocus(r=0.569,P<0.05),trefoil(r=0.382,P<0.05),coma(r=0.422?r=0.310,P<0.05),secondary Astigmatism(r=0.541?r=0.465,P<0.05),tetrafoil(r=0.303? r=0.455,P<0.05)and spherical(r=5.802,P<0.05)separately.No correlation was found with other parameters.The pupil's diameter of mydriasis was 8.21±0.15 mm.All eyes were with dysphotopsia,13 eyes(28.6%)were slight dysphotospia,19 eyes(43%)were moderate dysphotopsia,and 12eyes(27.4%)were serious dysphotopsia.The dysphotopsia was moderately positive correlation with defocus(r=0.473,P < 0.05)and without correlation with other parameters of Zernike polynomials.ConclusionConclusions: 1.both SMILE and ICL surgical procedures performed well with respect to surgical safety and effectiveness,Although the UDVA of patients who underwent SMILE was transiently better than that of patients who underwent ICL,the short-term postoperative objective visual quality of ICL was slightly better than that of SMILE in certain respects.However,no difference in the long-term outcomes was found between ICL and SMILE.2.The dysphotopsia is positive correlation with defocus.The main cause of dysphotopsia is the defocus caused by none correction area of ICL.