Incidence of dislocated and subluxed iris-fixated phakic intraocular lens and outcomes following re-enclavation

Abstract

Background: The purpose of this study was to establish the incidence of re-enclavation of iris-fixated phakic intraocular lenses in our centre and evaluate outcomes following re-enclavation.

Design: Retrospective observational case series. Single surgeon, hospital setting.

Participants: Six hundred and nine patients (1218 eyes) implanted with iris-fixated phakic intraocular lenses between 2000 and 2011.

Methods: Eyes requiring re-enclavation were identified, and outcome measures were evaluated 12 months following re-enclavation.

Main outcome measures: Rate of re-enclavation, uncorrected distance visual acuity and manifest refractive spherical equivalent were measured 12 months following re-enclavation.

Results: Twenty-five eyes (2% of eyes overall) of 20 patients required re-enclavation of a dislocated or subluxed phakic intraocular lens. Eight cases (32%) dislocated secondary to trauma and 17 (68%) subluxed spontaneously. No significant difference was detected (P = 0.59) in uncorrected distance visual acuity (logMAR equivalent) 12 months post-re-enclavation (0.18 ± 0.04) compared with that recorded 6 months post-initial uneventful phakic intraocular lens implantation (0.10 ± 0.06). No significant difference was detected (P = 0.95) in mean manifest refractive spherical equivalent 12 months post-re-enclavation (-0.59D ± 0.29D) compared with that recorded 6 months post-initial phakic intraocular lens implantation (-0.57D ± 0.17D). Following re-enclavation, mean endothelial cell count was 2627 ± 101 cells/mm(2) 12 months postoperatively in 16 eyes. This did not differ significantly from that recorded 6 months post-initial phakic intraocular lens implantation in these eyes (P = 1).

Conclusion: Dislocation and subluxation of iris-fixated phakic intraocular lenses may occur secondary to trauma or spontaneously because of inadequate iris enclavation. Re-enclavation can be carried out successfully with no significant adverse effect on clinical outcomes.

Keywords: dislocation; phakic intraocular lens (pIOL); re-enclavation; refractive phakic IOL.