Secondary Add On Iol Implantation For Pseudophakic Residual Ametropia In High Myopia

The object of our investigation was to evaluate the safety and efficacy of implanting a hydrophilic sulcus fixated Add-On IOL to correct resultant hyperopic refractive error after cataract surgery in myopic eye following uneventful phacoemulsification. Refractive surprises occur when high myopic cataract patients are implanted a low or negative powered IOL during phacoemulsification due to either A-scan errors (1) or less accurate IOL power calculation formulas in long eyes. Either piggyback implantation of another IOL in the bag   or Add-On IOL in the sulcus are found to be easy and safe technique to correct residual refractive errors than exchanging the original IOL

High myopic cataract patients  are usually  dissatisfied with large hyperopic refractive surprises when implanted a low power or negative powered IOL during phacoemulsification. We present such a case of refractive surprise following cataract surgery in highly myopic eye who after implantation of monofocal hydrophilic acrylic sulcus fixated add on IOL in presence of the primary IOL in the bag resulted  in 6/9 unaided vision without any perioperative complications

A high myopic cataract patient had pseudophakic refractive errors following implantation of negative powered or plano IOL during uneventful phacoemulsification. She was a 28 years old female, high Myopic with glass power -33D, axial length 35.67 mm, no posterior staphyloma had thick posterior subcapsular cataract in Right eye and good AC depth and endothelial cell count. Biometry with SRK T showed emmetropia with -19.0 D (refractive error -0.10) and astigmatism of -1.8/1.7. IOL diopter chosen was -17.5D (refractive error slightly more than -1.0). As, such diopter IOL was not readily available from any company a hydrophilic IOL was tailormade. Following uneventful phacoemulsification with IOL implantation in right eye she ended up with + 4.0 D for distance refractive error on spectacles to a vision of 6/9. We planned an add on IOL.  The refractive correction under cycloplegic was taken as +4.5 Spherical equivalent. The formula used was 4.5 multiplied by 1.5 for Add On IOL. Sulcofix of + 6.5 was used for implantation in sulcus over in the bag IOL following reassessment of ACD and endothelial cell count. Post-surgery patient had unaided 6/9 vision and is maintaining well after 6 months follow up with good  endothelial cell count of 2805 cells/ sq mm and no interlenticular opacification, good anterior chamber depth or any other complications overtime.

For highly myopic cataract patients a mild postoperative myopia (-2.0 to -3.0 D) is commonly recommended as they prefer to see the near objects more clearly than far objects .Implantation of a low power IOL in highly myopic eyes often tend to result in hyperopic refractive errors postoperatively.  For the correction, different surgical techniques are proposed, either corneal-based surgery (laser refractive surgery) or lens-based procedures (IOL exchange or piggy back IOLs). We conclude from our case that a secondary sulcus fixated Add-On IOL implantation is an effective and safe technique for the correction of resulting hypermetropia in high myopes following cataract surgery and implanted with negative or zero power IOL.