Risk Factors Associated with Haptic Malposition in Eyes Implanted with Implantable Collamer Lenses

Abstract

Purpose: To examine the risk factors for haptic malposition in eyes with implantable collamer lens (ICL). Setting: Eye and ENT Hospital, Fudan University, Shanghai, China. Design: Prospective non-randomized observational study. Methods: This study included 134 (77.9%) out of 172 initially enrolled patients who underwent ICL implantation and completed a one-year follow-up. The extent of haptic present in the ciliary sulcus (ICS) was measured. Patients were categorized based on ICS count (0-4). The position of the haptic was quantified as the distance between the iris root and the terminal tip of ICL haptic (iris root to haptic tip, IRH). The related factors to the ICS count and its correlation with the central vault were analyzed. Results: ICS distribution was: 0 ICS in 19 eyes (14.2%), 1 in 22 eyes (16.4%), 2 in 32 eyes (23.9%), 3 in 29 eyes (21.6%), and 4 in 32 eyes (23.9%). Parameters like maximum ciliary body thickness (CBTmax, P=0.008), iris ciliary process distance (ICPD, P<0.001), and ciliary process length (CPlength, P=0.034) varied significantly across ICS groups. A multiple linear regression analysis revealed that the iris-ciliary angle (ICA, P=0.006), CBTmax (P=0.007), the distance between the sulcus to sulcus plane and anterior crystalline lens surface (STSL, P=0.035), and ICL size (P=0.015) were significantly associated with IRH. Spherical equivalents (P=0.042), STSL (P=0.001), and ICS count (P=0.020) significantly correlated with the central vault. Conclusions: Shortened ciliary process is a primary risk for haptic malposition. The ICS count significantly relates to the central vault.