Accommodating intraocular lens study

Figure 1:  Oblique view demonstrating the hydraulic accommodating mechanism in situ (Courtesy of Frik Potgieter MD, FRCS) Figure 2":  Slitlamp view of accommodating optical element filled with sillicone oil (Courtesy of Frik Potgieter MD, FRCS) The FluidVision® (PowerVision, Inc.) accommodating intraocular lens (IOL) demonstrates excellent and stable monocular and binocular visual acuity at distance, intermediate for periods now reaching three years, according to Paul Roux MD, Pretoria, South Africa. A pilot study including 34 eyes from 26 patients who underwent implantation of the FluidVision lens was performed at a single centre by two surgeons. Eight patients underwent implantation of the lens in their fellow eye at 15 to 21 months after surgery on their first eye, Dr Roux said. He noted that, throughout 36 months of follow-up, the patients’ mean distance visual acuity remained very stable at 6/6. Furthermore, distance-corrected intermediate and near vision were 6/7.5 and 6/9, respectively. In addition, the mean amplitude of accommodation as measured by defocus curves in those implanted monocularly was about 3.0D throughout follow-up, he said. Furthermore, in those with the implant in both eyes it was around 4.0D. The speed of accommodation as measured with an autorefractor was also very rapid. Moreover, in response to a questionnaire, the binocularly implanted patients reported little or no difficulty in performing intermediate and near activities without spectacles and those with 12 months' follow-up said they were completely satisfied and would do the same again if they had it to do over again. He noted that the IOL has 6.0mm optic and an overall diameter of 10mm. The haptics of the hydrophobic lens are filled with a small volume of silicone fluid with the same refractive index as that of the optic. Its accommodative effect is achieved through the pressure exerted on the fluid-filled haptics in response to constriction of the ciliary muscles and relaxation of the zonular fibres in response to a near stimulus. That in turn pushes fluid from the haptic into the optic, causing an increase in its anteroposterior diameter resulting in an improved near focus. Dr Roux and his associates implanted the lens using a hydraulic injector device to facilitate the delivery of the large lens into the capsular bag. He noted that, in this initial series of patients, they used a 4.0mm clear corneal incision which they closed with a suture. The latest design of the FluidVision lens can be implanted through a 3.5mm incision which does not require a suture. It is also designed to achieve twice the accommodative power as the lens used in the study. Paul Roux, C/O Frik Potgieter MD, FRCS, Pretoria, South Africa: fjp@lasik.co.za