[Long term postural myopic shift assessment after posterior iris-claw aphakic intraocular lens implantation]

Posterior chamber iris-claw intraocular lens (IOL) is often used in aphakic eyes with inadequate capsular support. Postoperatively, patients may describe better capabilities for near reading in a face-down position. The goal was to evaluate the indications, visual outcomes and complications of this IOL and to compare postoperative spherical equivalent between the prone and the face-down position.

Retrospective single-center case series of 31 eyes of 28 patients who underwent surgery between 2007 and 2016. Visual outcomes, early and late complications were analyzed. The refractive measurements were also assessed using a portable refractometer in prone and face-down position for each patient. The spherical equivalents were then compared.

The mean follow up was 29 months (3-73). The final mean corrected visual acuity (0.17±0.5 SD LogMar) was significantly better than preoperatively (0.5±0.50 SD LogMar) (P<0.05). Postoperative refractive error was within±2 diopters of emmetropia in 95 % of patients. The mean spherical equivalents in prone and face down position were different (P<0.05),-0.44 diopters (-4;+2.75) and-1.38 diopters (-5.25; 1) respectively. A mean myopic shift of-0.95 diopters (-5.25; 1.00) was observed in face down position. Cystoïd macular edema (6 %) and IOL disenclavation (9.6 %) were the main complications.

A posterior iris-claw intraocular lens appears to be an effective and relatively safe IOL to treat aphakia with poor capsular support. When the patient's head is bent forward, a mean myopic shift of 1 diopter is observed. This may support the idea that this IOL could be considered as an accommodative implant. Anterior movement of the iris-IOL complex due to gravity may be responsible for this myopic shift.