ABSTRACT
【Objective】 To investigate the influencing factors of surgically induced astigmatism (SIA) in phacoemulsification. 【Methods】 Cataract phacoemulsification was performed in 69 patients with regular corneal astigmatism from December 2021 to March 2022. SIA of the anterior corneal surface, posterior corneal surface and simulated keratometry (SimK) in the diameter range of 3 mm, 5 mm and 7 mm centered at the apex of the cornea was observed. Pearson correlation analysis was used to analyze SIA with age, axial length (AL), anterior chamber depth (ACD), white-to-white (WTW), and central corneal thickness (CCT). Multiple linear regression was used to analyze the influencing factors of SIA. 【Results】 The mean age of the 69 patients was (63.25±14.74) years old, and 28 (40.58%) were male. The analysis found that the |SIA| of SimK was negatively correlated with WTW (r=-0.265, P=0.028), the |SIA| of 3 mm, 5 mm, 7 mm anterior surface was negatively correlated with WTW (r=-0.320, P=0.007; r=-0.337, P=0.005; r=-0.287, P=0.017), and the |SIA| of 3 mm, 5 mm, 7 mm posterior surface was negatively correlated with AL (r=-0.390, P=0.001; r=-0.352, P=0.003; r=-0.317, P=0.008). Multiple regression analysis showed that WTW was negatively correlated with |SIA| of SimK, 3 mm, 5 mm, 7 mm anterior surface and 3 mm posterior surface (B=-0.261, P=0.047; B=-0.387, P=0.016; B=-0.323, P=0.009; B=-0.297, P=0.041; B=-0.085, P=0.049). WTW was positively correlated with XSIA of 3 mm anterior surface, YSIA of 5 mm, and 7 mm anterior surface (B=0.347, P=0.040; B=0.318, P=0.034; B=0.403, P=0.010). AL was negatively correlated with |SIA| on the posterior surface of 3 mm and 5 mm (B=-0.023, P=0.021; B=-0.034, P=0.030). 【Conclusion】 During cataract surgery, the effect of ocular biological parameters such as axial length and corneal diameter on SIA should be considered.
ABSTRACT
Background The incidence of myopia is gradually increasing,and how to choose a better corrective method of myopia for the best visual demand is very important.Objective This study was to compare visual quality of implantable collamer lens (ICL) implantation with femtosecond laser in situ keratomileusis (FSLASIK) for moderate and high myopia using double-pass optical quality analysis system (OQAS).Methods A non-randomized controlled clinical trail was performed.Fifty-two eyes with-4.00 to-9.00 D of 26 consecutive patients were included in NO.1 Hospital of Xi'an from January 2015 to January 2016.Twenty-four eyes of 12 patients with the corneal thickness ＜500 μm received ICL implantation as ICL group and 28 eyes of 14 patients which corneal thickness was ≥500 μm underwent FS-LASIK surgery as FS-LASIK group.The demography was matched between the two groups (all at P＞0.05).All the patients were followed-up for 3 months after surgery.The preoperative best corrected distance visual acuity (BCDVA),spherical equivalent (SE),postoperative uncorrected distance visual acuity (UCDVA),BCDVA and SE were examined and compared between two groups.The parameters from OQAS were evaluated and intergrouply compared,including the objective scattering inders (OSI),modulation transfer function (MTF) cut off frequency,Strehl ratio and OQAS values under the contrast of 100％,20％ and 9％ (OV100,OV20,OV9).Results The postoperative BCDVA was not significantly different from preoperative UCDVA in both ICL group and FS-LASIK group (-0.04±t0.10 vs.0.05±0.12;-0.07±0.12 vs.0.00±0.12) (t=3.128,2.358,both at P＞0.05).No statistically significant differnces were found in SE,UCDVA and BCDVA after operation between ICL group and FS-LASIK group (t =1.292,0.900,-0.653,all at P＞0.05).OQAS examination showed that MTF cut off,OSI,Strehl ratio,OV100 were not significantly different after operation between ICL group and FS-LASIK group (t=-2.032,-1.440,-0.224,all at P＞0.05).The postoperative OV20 and OV9 were 0.82±0.14 and 0.80±0.21 in the ICL group,which were significantly higher than those in the FS-LASIK group(0.59±0.15 and 0.47±0.13) (t =4.105,4.702,both at P＜0.05).Conclusions Both ICL implantation and FS-LASIK provide good optical and visual quality for moderate to high myopic eyes,and ICL appears to have a better visual quality in comparison with FS-LASIK under the contrasts of 20％ and 9％.
ABSTRACT
Vascular endothelial growth factor (VEGF) family consists of a group of secreted dimeric glycoprotein with a cysteine knot motif of regularly spaced eight cysteine residues,which plays a key role in vasculogenesis,angiogenesis and lymphangiogenesis via their special receptors.VEGF-A,one of VEGF families,is essential for vasculogenesis and angiogenesis.So inhibition of VEGF is available in the treatment of cancer and some diseases of pathological angiogenesis.Some studies imply that VEGF receptor-2 (VEGFR-2)is expressed in some nonvascular tissue and exerts an important role in the differentiation and survival of the cells.The expressions of VEGF and VEGFR-2 in lens epithelial cells(LECs) can be detected in the formation of lens vescle in embryo stage to adult.VEGF secreted by lens itself is concerned with the differentiation and development of lens via autocrine and paracrine.