Abstract
Purpose: :
The aim of this study was to determine the correlation factors and features of membranous outgrowth onto the anterior surface of hydrophobic acrylic intraocular lenses.
Methods: :
This study included 145 eyes from 135 consecutive patients who had cataract surgery with implantation of a single-piece, foldable, hydrophobic acrylic intraocular lens (SA60AT, Alcon) from January 1 to April 1, 2010 in Zhongshan Ophthalmic Center, Sun Yat-sen University .Patients with ocular diseases other than age-related cataracts were excluded. All studies of the patients were performed with the approval of the center’s hospital ethics committee. Postoperatively, the IOL optic was examined by slit-lamp microscopy at 1 week and1 month to determine the incidence, extent, and correlation factors of membranous proliferation(MP) with SPSS13. If MP was present, we re-examined the patient monthly to monitor the condition. The extent of this proliferation was assessed using a clock-face representation of the IOL optic as the number of hours in which membranous proliferation could be identified.The variables assessed included age, gender, right vs left eye, preoperative visual acuity, ultrasound total time, ultrasound total equivalent power, postoperative visual acuity, ocular axial length, diopter of the IOL and grade of anterior vitreous opacity. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined for each variable.
Results: :
Twenty-four eyes were excluded from analysis and 121 remaining eyes were studied. Membranous proliferation was documented in 46 (38.02%) of the pseudophakic eyes. Furthermore, the incidence of membranous outgrowth was greater in pseudophakic eyes characterized by older age (OR:112;P=0.0018, shorter axial length (OR:0.29;P=0.0276), and more serious anterior segment vitreous opacity (OR:11.11; P<0.0001). Membranous proliferation was greater in the inferior (35.11%) and nasal quadrants (33.51%) than in the superior (18.09%) and temporal quadrants (13.30%) (where the incisions were made). The total area of membranous proliferation was slightly less than one quadrant (56.52%).
Conclusions: :
Shorter axial length, older age, serious anterior segment vitreous opacity, and the inferior and nasal quadrants are risk factors for membranous proliferation on the IOL surface. Appreciation of these risk factors may lead to establishing procedures that will lessen anterior capsule opacification and capsule contraction syndrome simultaneously.
Keywords: cataract • intraocular lens • clinical (human) or epidemiologic studies: risk factor assessment