Effect of Angle Opening Parameters on Corneal Endothelial Cell Density and Intraocular Pressure after Posterior Chamber Phakic Intraocular Lens Implantation

Abstract

This study aimed to investigate the time courses of angle opening parameters and the relationships of these with the corneal endothelial cell density (ECD) and the intraocular pressure (IOP) after posterior chamber phakic intraocular lens (Visian ICLTM, STAAR Surgical) implantation. We evaluated 116 eyes of 59 consecutive patients (mean age ± standard deviation, 34.0 ± 8.8 years) who underwent V5 implantable collamer lens (ICL) implantation. Preoperatively and 1 day, 1 week, and 1, 3, and 18 months postoperatively, we quantitatively measured the angle opening distance at 500 µm (AOD500), the trabecular-iris space area (TISA500), and the trabecular iris angle (TIA500), using anterior segment optical coherence tomography (CASIA 2, Tomey), and assessed the relationships of these measurements with ECD and IOP in ICL-implanted eyes. All angle parameters (AOD500, TISA500, and TIA500) significantly decreased 1 day postoperatively but remained stable thereafter. At 18 months postoperatively, we found no significant correlations of the angle parameters with ECD (Pearson correlation coefficient r = −0.108, p = 0.249 for AOD500; r = −0.162, p = 0.083 for TISA500; r = −0.022, p = 0.815 for TIA500) or between the angle parameters and IOP (r = −0.106, p = 0.256 for AOD500; r = −0.021, p = 0.826 for TISA500; r = −0.018, p = 0.850 for TIA500). The angle opening metrics significantly decreased immediately after ICL implantation but remained stable thereafter. Narrowing of the angle did not significantly affect ECD or IOP in ICL-implanted eyes during the 18-month postoperative period.

Prediction model of the horizontal trabecular iris angle after phakic posterior chamber implantable intraocular lens surgery

“…In a recent study, Kamyia et al reported a TIA 500 variation from 48.1 degrees preoperatively to 29.9 degrees at 18-month follow-up and no association was observed between the TIA 500 and IOP, corroborating previous findings. 23,25,27 Lim et al monitored the variation in TIA in eyes with shallow ACD (ACD <2.8 mm) reporting a reduction from 31.9 to 23.4 degrees, an mean reduction of 8.5 degrees, considerably smaller than the ACA closure reported in other studies. 29 This points to the fact that the anatomical features associated with a narrow preoperative ACA may modulate the amount of ACA closure.…”

“…15,23,24 Other studies enrolling different ethnical groups, particularly Chinese and Japanese individuals, have reported preoperative TIA values ranging from 40.0 to 58.4 degrees. 17,25–28 Lim et al reported a mean preoperative TIA of 31.9 degrees, which reflects the association between the ACA and the ACD, in patients with ACD lower than 2.8 mm (the minimum ACD recommended by the manufacturer). 29 In the present study, the TIA 750 correlated positively with the corneal sagittal height ( R = 0.534) and the ACD ( R = 0.503) and negatively with the CLR ( R = −0.433).…”

Efficacy and safety after posterior chamber Implantable Collamer Lens implantation according to preoperative anterior chamber depth: Short-term comparative study

“…Recent studies have addressed the relationship between the value of preoperative ACD and the level of angle narrowing, ECD loss or IOP rise. Eissa et al 16 have demonstrated that after ICL implantation there is a significant IOP increase and a decrease of the ACA during follow-up; Kamiya et al 6 demonstrate that after ICL implantation, the decrease in the ACA is not correlated with the ECD loss or the IOP increase. We have found weak or no correlation between the preoperative ACD and ACA values, the change in endothelial cell density, or IOP increase after surgery; confirming the safety of ICL implantation in eyes with a shallow preoperative ACD between 2.80 and 3.00 mm.…”

“…5 While there is an inverse correlation between the central vault and the anterior chamber angle, recent publications have demonstrated no correlation between the anterior chamber angle and volume and the loss of endothelial cell density (ECD) or the intraocular pressure (IOP) increase after surgery. 6…”

“…5 While there is an inverse correlation between the central vault and the anterior chamber angle, recent publications have demonstrated no correlation between the anterior chamber angle and volume and the loss of endothelial cell density (ECD) or the intraocular pressure (IOP) increase after surgery. 6 Two previous studies have reported the outcomes of ICL implantation in patients with ACD lower than 2.80 mm, implanting the pIOL in an off-label use with special patient consent. 7,8 The mentioned studies reported on two small retrospective samples; both demonstrated a significant endothelial cell loss, a significant reduction of the ACA (−42.7%), 7 an elevated proportion of patients with high-risk occludable angle (22% of eyes below 20 degrees), 8 and a higher incidence (11.1%) of anterior subcapsular cataracts.…”