Abstract
Abstract: :
Purpose: To evaluate the relative intraocular position and anatomic relationships of ICL (Staar Surgical) and PRL (Cibavision Surgical) posterior chamber phakic intraocular lenses (PCP IOL) using ultrasound biomicroscopy (UBM). Methods: 17 phakic myopic eyes corrected by ICL (mean preoperative spherical equivalent = – 14.2 ± 2.3 diopters), and 14 phakic myopic eyes that had had PRL implantation (mean preoperative SE = – 13.1 ± 4.5 diopters), were examined by UBM. UBM exams were performed 12.6 ± 5.2 months after surgery. The main parameters measured and compared were: anterior chamber depth, central and peripheral distance between PCP IOL and the crystalline lens, exact lens haptics position, and angle opening distance. Results: No statistical difference between ICL and PRL groups was found for preoperative anterior chamber depth. The mean postoperative distance between the PCP IOL and the central endothelium was 2398 ± 203 µm and 2640 ± 230 µm in the ICL and PRL groups respectively (p < 0.005). The central vault between the implant and the crystalline lens was greater in eyes with ICL (ICL = 402 ± 194 µm, PRL = 256 ± 187 µm, p < 0.05). However, the incidence of lens contact on the peripheral level was higher in the ICL group (41 %) than in the PRL group (29 %), and the difference between the two implants in the peripheral crystalline lens–PCP IOL distance was significant (ICL = 168 ± 144 µm, PRL = 264 ± 144 µm, p < 0.05). Both IOL haptics appeared to be correctly positioned in the sulcus in 13 (76 %) eyes of ICL group, and on the zonule in 8 eyes (57 %) of PRL group. In 5 eyes (36 %) corrected by PRL, rotation of the lens was observed. UBM showed contact between the iris and the PCP IOL in all eyes. Conclusions: PCP IOL implantation represents a safe procedure for the correction of high myopia with regard to refractive results. However, mechanical contact between the PCP IOL and the crystalline lens are findings that suggest caution regarding the long–term safety of these implants. UBM provides a unique tool to noninvasively evaluate the relations of these implants within the posterior chamber, and help to analyze the mechanisms of crystalline lens and iris complications.
Keywords: imaging/image analysis: clinical • myopia • refractive surgery: phakic IOL