Evaluation of biometric indicators of anterior segment parameters after ICL implantation by swept-source optical coherence tomography

Abstract

Abstract Purpose. To evaluate the anterior segment structure alteration after implantable collamer lens (ICL) implantation in myopic patients using swept-source quantitative optical coherence tomography (SS-OCT). Methods. This prospective study included 47 eyes of 24 patients with preoperative spherical equivalent ≥ -3.00 D. Patients underwent ICL implantation at Department of Ophthalmology, Peking University Third Hospital, from May 2021 to December 2022. SS-OCT was used to measure biometry including anterior chamber width (ACW), angle opening distance (AOD), angle recess area (ARA), trabecular iris area (TISA), trabecular-iris angle (TIA), iridotrabecular contact (ITC) area and ITC Index before ICL implantation surgery and at 1 month follow-up. Results. At one month following ICL implantation, the ITC area is 0.396 ± 0.37 mm2, and the ITC index is 8.143 ± 5.439 %. All angle parameters, with the exception of ACW, showed a statistically significant reduction on SS-OCT (P<0.05). Mean AOD500, AOD750, ARA500, ARA750, TISA500, TISA750, TIA500 and TIA750 values at one month postoperatively declined by 60.0%, 60.4%, 58.1%, 59.2%, 57.3%, 58.7%, 48.8% and 50.7%, respectively. Vault was positively correlated with ITC index and the percent change in anterior chamber parameters. The vault of >0.659mm was found to be optimal for angle-closure suspect with a sensitivity of 85.2% and a specificity of 53.9%. Conclusions. Anterior chamber parameters decreased 1 month after ICL implantation, and their percentage changes and ITC index correlated with the vault. When the vault is larger than 0.659mm, it is necessary to be alert to possible closed angle suspicion.