Comparison Of Phakic Iols (Ipcl And Icl) Size And Vault Height With Predictive Formulas Onanterior Segment Ocular Coherence Tomography (Asoct)

To compare and evaluate the results of phakic Intraocular lenses (IPCL V2.0, Caregroup Sight Solutions, India Vs ICL,STAAR surgicals, Switzerland) postoperative vault height to preoperative predicted vault height, lens size, Crystalline lens rise(CLR)on cassia ASOCT, and to evaluate the safety  in terms of postoperative vault height

Retrospective study conducted at Refractive Services of a tertiary care institute in India

A total of 40 eyes underwent Phakic IOL implantation(20 eyes IPCL and 20 eyes  ICL).Preoperative ASOCT was done to document ICL size through NK and KS formula, CLR and predicted postoperative vault height .All patients white to white was taken from digital callipers,IOL master and Pentacam. Postoperative vault height was calculated at the end of 1 month using ASOCT

The mean preoperative Best corrected visual acuity was 0.2 Log MAR, the mean preoperative sphere was -9.06±5.53D(10.76±6.88 in IPCL,7.52±3.46D in ICL) and cylinder was -2.01±1.6D(-1.82±1.18 in IPCL,-1.86±1.33 in ICL), ACD was 3.18±0.2mm, WTW  was 11.64±0.47,11.62±0.43and 12.01 ±0.45 respectively with digital callipers,with pentacam and IOL master.AL was 26.56±2.29mm. The predicted ICL size on cassia ASOCT with NK formula was 12.62±0.32, and vault height was 547.26±104.86mm and Icl size with KS formula was 12.53±0.31 and predicted vault height was 485.05±52.97.The ICL Size implanted was 12.78±0.58.Post operative vault height calculated at the end of 1 month on ASOCT was 713.59±268.52mm.

Pentacam device was closest to digital callipers in WTW measurements

Using NK and KS Formulas

        - Both prediction formulas tend to select a smaller IPCL size than the actual nomogram.

        - In higher vault height eyes NK and KS formula preoperatively predicted lesser lens size compared to the implanted size

        - In Lower vault height eyes NK and KS formula preoperatively predicted higher lens size compared to the implanted size.

In addition to traditional methods, referring to the NK and KS formulas can lead to a more accurate and predictable postoperative vault height, especially in boderline cases.