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

Abstract

Background To evaluate anterior segment structural alterations 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 in 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 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. The correlations among the ITC index, vault, and angle parameters were analysed. Receiver operating characteristic (ROC) analysis was used to explore the ability of the vault to identify eyes with suspected angle-closure. Results At one month following ICL implantation, the ITC area was 0.396 ± 0.37 mm2, and the ITC index is 8.143 ± 5.439%. All angle parameters, except 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 decreased by 60.0%, 60.4%, 58.1%, 59.2%, 57.3%, 58.7%, 48.8%, and 50.7%, respectively. The vault was positively correlated with the ITC index and percent change in anterior chamber angle parameters. A vault of > 0.659 mm was found to be optimal for angle-closure suspect with a sensitivity of 85.2% and a specificity of 53.9%. Conclusions Anterior chamber angle parameters decreased one month after ICL implantation, and their percentage changes and ITC index correlated with the vault. When the vault is larger than 0.659 mm, it is necessary to be alert to possible closed angle suspicion.

A comparative study of two phakic posterior chamber implantable lenses

“…This was the first study to compare ACA500 and AOD500 after phakic IOL implantation, which has been exclusively addressed in existing literature on glaucoma. [ 23 , 31 ] In our study, we observed a significant decrease in the ACA and AOD parameters at 12 months after surgery compared to before the operation. There were no significant differences in the ACA and AOD values observed between ICL and IPCL implantation.…”

“…[ 23 , 30 ] The AOD500 is the distance from the posterior cornea surface and the anterior iris surface, which is measured on a line perpendicular to the trabecular meshwork 500 μm from the scleral spur. [ 23 , 30 , 31 ] The measures of ACA500 and AOD500 are shown in Figure 1 .…”

Causes and management strategies for elevated intraocular pressure after implantable collamer lens implantation

“…Where device availability permits, intraoperative use of OCT assisted ICL implantation helps to achieve the ideal vault ( 34 ). After ICL implantation, regular observation of vault changes using slit-lamp microscopy and AS-OCT can help prevent early elevated IOP and glaucoma, thus avoiding late-stage vision impairment ( 35 ). Figure 3 shows observation of lens vault using slit lamp after ICL implantation.…”

Implantable Collamer Lenses (ICL) for treating keratoconus

“…Lin et al noted decreased central anterior chamber depth (CACD) and anterior chamber volume (ACV) postoperatively, with stabilization observed over time, while Tang et al found reductions in anterior chamber angle parameters one month post-ICL implantation. These ndings show the need for long-term monitoring of anterior chamber parameters after ICL implantation to ensure patients have long-term ocular health [12,13].…”