The Institutional Review Board of the Eye and ENT Hospital of Fudan University approved the protocol of this retrospective analysis study (the ethical approval reference number: No. 2013021). All procedures adhered to the tenets of the Declaration of Helsinki. All of the patients or guardians provided written informed consent for the surgical procedures and for the use of their medical records for research purposes.
We performed a retrospective review of the medical records of 77 eyes in 53 patients (31 males and 22 females) who underwent SF-PC-IOL implantation between January 2005 and June 2014 at the Eye & ENT Hospital of Fudan University, Shanghai, China. All eyes included in this study lacked the support of a continuous lens capsule in > 4 clock-face hours. The SF-PC-IOLs were implanted at the time of surgery for lensectomy and anterior vitrectomy to treat lens subluxation. After surgery, patients aged < 7 years old who had unilateral lens subluxation underwent treatment of amblyopia by patching the healthy eyes.
Either eyes of patients were excluded if RD or other complications occurred before the primary operation. Eyes were also excluded if they had a history of ocular surgery or received post- operative follow-up for fewer than 12 months.
The clinical assessments included best-corrected visual acuity (BCVA), refraction, sensorimotor examination of eye alignment/eye movement, measurement of intraocular pressure (IOP), slit-lamp examination, fundoscopy, keratometry before and after surgery, assessment of the IOL position after surgery.
After surgery, anterior segment optical coherence tomography (AS-OCT; (CASIA2 anterior segment OCT; Tomey, Nagoya, Japan) was performed to analyse the IOL’s decentration and tilt using the anterior segment single-scan mode. Cross-sectional images of the IOL were obtained. IOL dislocation was defined as decentration of > 1 mm and IOL tilt was defined as a tilt angle of > 5° [8, 9]. The distance between the optical axis of the eye and the centre of the horizontal axis of the lens was calculated using Matlab (Mathworks, Natick, MA, USA), and the level of decentration was determined using this distance. The angle between the optical axis of the eye and the vertical axis of the lens was also calculated using Matlab, and was used to determine the tilt angle.
Before surgery, informed consent was obtained from the patients or their guardians. All surgeries were done by one surgeon (LY) and SF-PC-IOLs were implanted using the following technique.
Conjunctival peritomy were performed near two sides of corneoscleral limbus first. A transscleral suture was placed through the bed of two scleral flaps (4:00 and 10:00 positions or 2:00 and 8:00 positions) using the classic ab externo technique with a double-armed 10–0 polypropylene suture (Prolene; Ethicon Inc., Somerville, NJ). Then the loop of the suture was externalised through a 2.6-mm temporal clear corneal incision at 12:00 position with a hook and cut in the middle. The suture was either tied to the two haptic of IOL, and the haptics were drawn into the ciliary sulcus. The external knot was covered by the scleral flap. The scleral flap was sutured flat with a 10–0 nylon suture before conjunctival closure with a 8–0 nylon suture.
Following four kinds of PC-IOLs were used for scleral fixation in this cohort of patients: 1. HumanOptics model MCX11ASP (HumanOptics AG, Erlangen, Germany), a single-piece hydrophilic acrylic plate lens with 7.0 to 5.5 mm diameter optic and two modified frame haptics. 2. Alcon model CZ70BD (Alcon, Fort Worth, TX, USA), a single-piece polymethylmethacrylate lens with 7.0 mm diameter optic and two modified C-style haptics desighed with eyelet on it. 3. Rayner model 920H (Rayner, UK), a single-piece hydrophilic acrylic lens with 6.25 mm overall length of optic and two closed loop designed C-style haptics. 4. Abbott Medical Optics model AR40e (Abbott Medical Optics, Santa Ana, CA, USA), a three-piece hydrophobic acrylic lens with 6 mm diameter optic and two 60% Blue core PPMA modified C-style haptics.
All analyses were performed using SPSS version 20.0 (SPSS, Chicago, Illinois, USA). Follow-up times were counted according to the unit of eyes due to different operation time of bilateral primary SF-PC-IOL implantation. Patients’ gender and etiology are expressed as the number and percent of patients. All clinical measurements (included BCVA, IOP, postoperative complications) are expressed as the number and percent of eyes. Continuous variables are expressed as the mean ± standard deviation (SD). Paired t tests were used to compare the preoperative and postoperative variables. Independent samples t test, one-way ANOVA analysis and Chi-Square tests were used to compare in subgroups. Cox regression analysis and survival analysis were used to identify risk factors for postoperative complications. Values of p ≤ 0.05 were considered statistically significant.