New IOL: Results
New design provides moderate accommodation
A new intraocular lens (IOL) with a different style hinged optic-haptic juncture from older accommodative IOLs appears to provide a moderate forward shift in response to pilocarpine-induced ciliary muscle contraction, but at the cost of increased posterior capsule opacification (PCO), according to a study presented at the 21st ESCRS Winter Meeting in Maastricht, The Netherlands, by Nino Hirnschall MD, PhD.
The study included eight patients with a mean age of 69 years. All received the new accommodating IOL (ActaLens™, Emmetrope, designed by Andrew Phillips) in one eye and a control IOL, either the Crystalens® (Bausch + Lomb) or the AcrySof® IQ (Alcon) in the fellow eye, said Dr Hirnschall, Vienna Institute for Research in Ocular Surgery (VIROS), Hanusch Hospital, Vienna, Austria.
At 20 months’ follow-up, the researchers measured anterior chamber depth (ACD) with an optical biometry device (Lenstar, Haag-Streit AG, Switzerland) on two measurement days. On the first measurement day they determined ACD prior to instillation of topical pilocarpine and 30 minutes later. On the second measurement day, they followed the same procedure but used 1% cyclopentolate instead of pilocarpine.
They found that pilocarpine reduced ACD by a mean of 0.32mm (p=0.014) in the ActaLens group compared to only 0.04mm in the control group (p=0.854). In addition, cyclopentolate increased ACD by 0.14mm in the ActaLens group (p=0.014), compared to only 0.03mm in the control group (p=0.181).
A disadvantage of the new accommodating IOL was an increased level of PCO. Two independent examiners graded PCO, on a scale of 0 to 3, as 2.4 in the ActaLens group, compared to 1.8 in the Crystalens group and 0.l1 in the AcrySof group (p<0.001). In addition, Nd:YAG rates were higher in the study group, but the difference did not reach statistical significance.
Dr Hirnschall noted that the ActaLens is a forward-vaulted plate silicone IOL with hinges between the haptic and the optic. It has a total length of 11mm and an optic diameter of 5.5mm. During production, the IOL is flattened with a vicryl suture. Patients undergo cycloplaegia during the first four weeks after surgery. Laser suturolysis performed six weeks after surgery allows the optic to move forward to its accommodating non-planar state during ciliary muscle contraction.
“The investigated IOL is a novel concept for an accommodating IOL and results showed a moderate pilocarpine-induced forward shift of the IOL. However, the investigated IOL seems to have a higher PCO rate compared to standard monofocal IOLs,” he concluded.
Nino Hirnschall: firstname.lastname@example.org