gms | German Medical Science

Objective: Since 2006 our laboratory has received an increased number of explanted intraocular lenses (IOLs) within the capsular bag forwarded for pathological evaluation; some specimens also contained a capsular tension ring (CTR). Clinical and pathological findings from cases with this complication are described.

Design: Retrospective case series with clinico-pathological correlation.

Participants: Eighty-six IOLs explanted within the capsular bag, as well as 23 explanted subluxated/dislocated capsular bags containing a CTR and an IOL submitted in formalin.

Methods: Standard gross and light microscopy of specimens, complete histopathological analyses of selected specimens done at the University of Utah, as well as questionnaire sent to explanting surgeons, and patient chart review, when available.

Main Outcome Measures: Lens design, material, and abnormalities, capsular bag anomalies, patient demographic data, surgical dates, and presence or absence of known risk factors.

Results: This series included PMMA, silicone and hydrophobic acrylic lenses, manufactured with both 1-piece and 3-piece designs. The mean time from surgery to spontaneous IOL dislocation was 8.5 years. The main conditions associated with the cases of IOL dislocation were as follows: Pseudoexfoliation 50%, prior vitreoretinal surgery 19%, history of trauma 6%, uveitis 2%, and none/unknown 23%.

Regarding the cases with a CTR, the IOLs were 3-piece hydrophobic acrylic (N=11), 1-piece hydrophobic acrylic (N=6), 3-piece silicone (N=4), or 1-piece hydrophilic acrylic (N=2) designs; all CTRs were made of PMMA. Available information on associated ocular conditions included pseudoexfoliation (N=17), glaucoma (N=4), vitrectomy/retina surgery (N=3), and trauma (N=1). Complete histopathological assessment in 3 specimens showed signs consistent with pseudoexfoliation, without available history related to this condition in one of the cases. Moderate/severe degrees of Soemmering’s ring formation and capsulorhexis phimosis were observed or reported in 13 and 11 specimens, respectively. Fourteen eyes were implanted and explanted by the same surgeon, with an interval of 92.7±23.4 months between the procedures. His rate of explantation because of subluxation/dislocation was 0.76% of the CTRs implanted during the time considered.

Conclusions: Patients with any type of IOL are at risk for late in-the-bag dislocation. Pseudoexfoliation and vitreoretinal surgery were the most common associated conditions in this series. Irrespective of the presence of known risk factors, IOLs dislocated on average 8.5 years after phacoemulsification and IOL implantation.

Explantation because of postoperative subluxation or dislocation of CTR-IOL-capsular bag complexes occurred approximately 6.8 years after implantation in this series, providing further evidence that a fine line exists between zonular insufficiency that can be stabilized with the CTR alone and that requiring further support. Analyses of large series may help define common factors associated with this complication, as well as surgical planning and employment of various endocapsular support devices to enhance postoperative zonular stabilization.