ABSTRACT
AIM:To investigate the relationship among lens parameters and their correlation with ocular anatomic characteristics in myopia patients implanted with posterior-chamber phakic implantable collamer lens(Phakic-ICL).METHODS:Retrospective study. A total of 46 myopia patients(46 eyes)who underwent Phakic-ICL implantation were collected in the Wuxi Huaxia Eye Hospital from June 2022 to June 2023. Preoperative evaluation of ocular anatomical characteristics included corneal central thickness(CCT), anterior chamber depth(ACD), axial length(AL), white-to-white(WTW), horizontal sulcus to sulcus(STSH), horizontal angle to angle(ATAH), and vertical sulcus to sulcus(STSV), vertical angle to angle(ATAV). Furthermore, lens parameters included horizontal crystalline lens rise(CLRH), vertical CLR(CLRV)and vertical lens thickness(LTV). The difference, consistency and correlation of the above parameters were analyzed.RESULTS:Except for differences between WTW and STSV, STSH and ATAV, which were not statistically significant(all P>0.05), the other horizontal and vertical ocular anatomical characteristics were statistically significant(P<0.05). CLRH and CLRV had statistically significant difference(P<0.01), while LTH and LTV were not statistically significant difference(P>0.05). Bland-Altman results revealed that the anatomical characteristics in the horizontal or vertical diameters showed poor consistency. The consistency between CLRH and CLRV was poor. There was consistency between LTH and LTV, with the 95% limits of agreement(LoA)between the differences ranging from -0.21 to 0.28 mm, and the proportion of out-of-line points off the 95% LoA was 4.35%. Pearson correlation analysis revealed that there were correlations between the anatomical characteristics of the horizontal and vertical diameters(P<0.01). Meanwhile, there was no correlation between the anteroposterior diameters(P>0.05). There were correlations between the lens parameters(P<0.05), excepted for the CLRH, LTH and LTV, which had no correlation. AL correlated with the anatomical characteristics of the horizontal and vertical diameters(P<0.05), but it had no correlation with lens parameters(P>0.05). Multiple linear regression analysis revealed that LT=0.419+0.017×age-0.548×ACD+0.371×ATAH+0.884×CLRV, CLRH=-0.443+0.809×CLRV, CLRV=-0.092-0.200×ATAH+0.560×CLRH(corrected R2=0.458, 0.482, 0.589, respectively).CONCLUSION:Horizontal and vertical diameters were not interchangeable. CLRH and CLRV were not interchangeable, while LTH and LTV were interchangeable. Partial lens parameters, WTW, STS, and ATA were correlated with ACD. Finally, age, ACD, ATAH, and CLRV influenced LT.
ABSTRACT
Implantable collamer lens(ICL)and toric ICL(TICL)are clinically common types of posterior chamber phakic intraocular lenses, they are mainly used to correct high myopia and low-to-moderate myopia of eyes whose corneal conditions are not suitable for corneal laser surgery. Accurate preoperative measurement, safe intraoperative implantation and appropriate postoperative location of lenses are critical to ensure the outcome of ICL implantable, and the appearance of V4c ICL with a central hole ensures the safety of this surgery to a greater extent. However, the intraocular position of both ICL and TICL is not invariable. Some studies have shown that the vault has a trend of decreasing year by year after ICL surgery, but its reason is unknown. And spontaneous rotation may occur after the TICL surgery, thereby causing visual loss, which is one of the main causes of TICL replacement. And postoperative changes in the position of the central hole also need attention. In addition, the visual quality of the operated eye will change after ICL/TICL implantation, but whether the change of intraocular positions of implanted lenses will affect the postoperative visual quality is also a problem that needs to be paid attention to and explored. Therefore, this paper reviewed the postoperative changes in vault, TICL axis, position of the central hole and their causes, as well as the effects of these changes on postoperative visual quality, offering valuable clinical guidance for accurate preoperative selection of ICL/TICL and surgical design, so as to improve the effectiveness and stability of ICL implantation in correction of myopic refractive error.
ABSTRACT
With the development of posterior chamber phakic intraocular lenses implantation and the constant improvement of the implantable collamer lens(ICL), ICL V4c implantation has become one of the main methods for correcting moderate and high myopia. Vault is an important indicator to evaluate the security of posterior chamber intraocular lens implantation. In recent years, optimizing surgical procedures to obtain the ideal vault in ICL V4c implantation surgery has become a research hotspot. This paper aims to provide help for improving surgical safety by summarizing and analyzing the optimized programs of ICL V4c implantation surgery. The focus will be on preoperative examination, intraoperative surgical design, and postoperative follow-up.