The Iol-k implant for central low vision : a pilot study

Purpose:To evaluate the efficacy of the IOL-Kiara® system, a mixed intra/extra ocular Galilean telescope, to improve vision of patients with severe low vision due to macular degeneration. Methods:4 patients (age range 72-78 years) with senile cataract and atrophic age related macular degeneration underwent phacoemulsification and implant of IOL-K®, an acrylic foldable IOL with a central negative (-26 diopters) 2 mm in diameter portion. The negative IOL represents the ocular of a Galilean telescope, whereas the objective is a positive lens set on a special pair of glasses. Such a Galilean system gives 2,7x magnification for distance. Results: After surgery three patients showed visual acuity improvement (ETDRS charts mean preop visual acuity 1,7 logMAR, postop 1,3 logMAR). Further improvement was gained when completing the Galilean telescope by adding the glasses positive lens correction (mean visual acuity: 0,78 logMAR). The fourth patient remained stable. Conclusions:This pilot study shows that IOL-Kiara® system can improve visual acuity in severe low vision due to macular conditions. In order to avoid discomfort due to the high magnifying effect of the complete system, patients should use the positive correction of glasses only for motionless activities (watching TV, reading, meals, etc). This system is a valid alternative for patients for whom the lesser magnification (1,3x) of the IOL-Vip implant (Ophthalmology 114: 860-865, 2007) is not sufficient for a satisfactory visual improvement and/or patients with ocular condition contraindicating the anterior chamber implant of the IOL-Vip system (low endothelial cell count, shallow anterior chamber, glaucoma).