Analysis Of The Causes Of Abnormal Vault After Implantable Collamer Lens Implantation

Objective: To investigate the related factors affecting vault after implantable Collamer lens implantation and to analyze the causes leading to replace intraocular lens.Methods: A retrospective analysis was made on 186 eyes of 96 patients who underwent implantable Collamer lens implantation including seven patients(7 eyes)underwent intraocular lens replacement.Biometric parameters including refraction,white to white(WTW),anterior chamber depth(ACD),anterior chamber volume(ACV),axial length(AL)and mean corneal curvature(Km)were collected before surgery.The vault was assessed by pentacam anterior segment diagnostic system 3 months after surgery.Multiple stepwise regression analysis was employed to identify the variables correlating with the vault,and to analyze the causes of intraocular lens replacement for the vault of too low or too high.Result: The average age of 186 eyes of 96 patients was 25.17 ± 4.57 years old.There were 37 males(70 eyes)and 59 females(116 eyes).The average vault was 431.90 ±243.80 Um 3 months after operation.There was a linear correlation between vault and anterior chamber depth(ACD),axis length(AL)and corneal horizontal diameter(WTW),ACD had the greatest influence on vault.The regressive equation of vault was: vault(mm)= 416.139 x ACD(mm)+100.472 x WTW(mm)+25.620 x AL(mm)-2744.692,adjusted R2 was 0.318.The average age of 7 eyes of 7 patients underwent intraocular lens replacement was 27.57 ±4.58 years old,of which 4 eyes(57.14%)were due to too low vault and 3 eyes(42.86%)were due to too high vault.The causes leading too low vault included a too-small WTW measurement,a too-small ICL model and a larger horizontal ciliary sulcus diameter than WTW diameter.The causes leading too high vault included a oversized WTW measurement and ciliary body cysts are located at the position where the haptics of the ICL are placed.Conclusion: There is a linear relationship between vault and ACD,WTW and AL,and ACD has the greatest influence on vault.The main causes of abnormal vaulting and subsequent ICL exchange included a WTW measurement error,a small ICL model selection,a larger horizontal diameter of ciliary sulcus than WTW,and ciliary body cysts are located at the position where the haptics of the ICL are placed.