Retrospective Study Of Residual Anterior Chamber Depth After ICL Implantation

Objective: To investigate the residual anterior chamber depth(RACD),the rate of the shallow anterior chamber,and evaluate the correlation between RACD and the anterior chamber angle(ACA)after Implantable Collamer lens(ICL)implantation.To remind clinical ophthalmologists to pay attention to the long-term risk of angle-closure glaucoma in patients with a shallow anterior chamber after ICL implantation.Methods: A multicenter retrospective study.This study was divided into 2 parts.Part 1 included 1810 eyes that underwent ICL implantation in4 hospitals.Data on age,gender,visual acuity,intraocular pressure,and Pentacam-based anterior segment parameter results were collected.In part2,64 patients(123 eyes)who underwent ICL surgery at the Changsha Aier Eye hospital were collected.The ocular variables above was performed,and anterior segment optical coherence tomography(AS-OCT)examination was performed.Meanwhile,33 eyes recorded the ICL haptic and postoperative ACA’s position in different axes.T-test,Correlation analysis,multiple linear regression analysis,and other statistical methods were used for analysis.Results: Part 1: In the selected 1810 eyes,the average RACD was2.30±0.25 mm,an average decrease of 0.92 mm compared with preoperative.201(11.10%)eyes had RACD≤2.0 mm.The mean LV was460.91±222.07 μm.Grouped by RACD,The mean LV(709.97±250.52 μm)of eyes with RACD≤2.0 mm was significantly higher than that with RACD>2.0 mm(429.79±197.36 μm,P =0.000).62.19% of the eyes with RACD≤2.0 mm had vaults between 250 and 750 μm.Compared to the anterior segment parameters of the two groups,There were significant differences in ACD and LV between the two groups,and there were no significant differences in other ocular variables.RACD was significantly positively correlated with ACD(P=0.000)and was significantly negatively correlated with LV(P=0.000).ACD and LV were both linearly correlated with RACD(R2=0.720).Part 2: In 123 eyes,the average postoperative ACA was 23.21±5.20°,and 25.2%(32 eyes)had an ACA less than 20°.Postoperative ACA was positively correlated with preoperative ACD(r=0.43,P<0.001),RACD(r=0.72,P<0.001)and negatively correlated with LV(r=-0.221,P=0.014).Linear regression analysis showed that only RACD had a linear relationship with postoperative ACA(R2=0.521).There was no significant difference in the effect of the position of the ICL haptic on the postoperative ACA of different orientations.Conclusions: In this study,the LV of some patients after ICL implantation was in an optimal range,but the RACD was ≤ 2.0 mm.There was a strong correlation between the RACD and the postoperative ACA,indicating that patients with a shallow residual anterior chamber corresponded to a narrower postoperative ACA.This stenosis may be omnidirectional,with the risk of atrial angle closure.Therefore,when reviewing patients after ICL implantation,clinicians should pay attention to patients’ RACD to avoid the potential risk of angle-closure.