ABSTRACT
Cataract extraction is often combined with the implantation of intraocular lens (IOL) with the diopter matching the operated eye to restore optimal visual function after surgery.However, there are often errors between the actual refractive power of the operated eye and the predicted value.One of the major causes of postoperative refractive error is the change in IOL position compared with the expected position.In order to improve the accuracy of postoperative refraction prediction, Holladay proposed to introduce the concept of effective lens position (ELP) into the IOL diopter calculation formula.The differences in the parameters and algorithms incorporated in the calculation of ELP lead to differences in the accuracy of IOL calculation formulas.With the application of multi-parameter calculation methods, especially the formula based on the artificial intelligence algorithm, the accuracy of IOL calculation formula has been significantly improved.ELP is also affected by various factors such as differences in ocular anatomy, IOL design and material, and surgical procedures, especially the factors affecting the stability of the capsular bag that increase the difficulty of accurately predicting ELP.Therefore, the changes in postoperative ELP need to be further discussed in order to obtain more accurate postoperative refraction.This article aimed to give a review of the development of calculation formulas and the influencing factors of ELP.
ABSTRACT
Objective To investigate the relationship between intracranial atherosclerotic plaque stability and stroke recurrence risk.Methods Forty-eight patients with acute ischemic stroke caused by intracranial atherosclerosis in Guangdong Province Hospital of TCM were analyzed retrospectively.After the Essen Stroke Risk Scale (ESRS) was used to assess the risk factors for the patients,they were divided into either an ESRS ≥3 group (n=21 in the high-risk recurrence group) or an ESRS <3 group (n=27 in the low-risk recurrence group).Both groups of patients underwent high-resolution MR imaging (HR-MRI) examinations of the intracranial guilty vessels (basilar artery or unilateral middle cerebral artery).According to the signal intensity of HR-MRI on the T1-weighted imaging,T2-weighted imaging,and T1 fat suppression sequences,the intracranial atherosclerotic stable plaques and unstable plaques were distinguished.The stabilization of intracranial atherosclerotic plaques was compared in patients of both groups.Results There were significant differences in the age and incidences of hypertension,diabetes mellitus,and unstable plaques in patients of both groups (P<0.05).Further multivariate logistic regression analysis of the four factors showed that the age,hypertension,diabetes,and intracranial atherosclerotic unstable plaques were the high-risk factors for recurrent ischemic stroke (ORs,87.114,159.423,8.942,and 11.551,respectively;95%CIs 4.218-1 799.078,3.235-7 855.957,1.054-75.857,and 1.011-132.043,respectively;all P<0.05).Conclusion In addition to the traditional risk factors such as age,hypertension,and diabetes,the intracranial atherosclerotic unstable plaque is an independent risk factor for high-risk recurrence of ischemic stroke.