New intraocular implant plans ahead
Implant maintains space for in-the-bag placement of piggyback IOLs.
A new implant combining an IOL optic with a device to maintain space within the capsular bag to receive a piggyback IOL months after cataract surgery has been successfully tested in humans, Gabriel A Quesada MD told the American Society of Cataract and Refractive Surgery 2018 Annual Symposium in Washington DC, USA.
The device allows any standard IOL to be implanted within the capsular bag to correct residual refractive error rather than relying on a specialised lens placed in the sulcus.
Inserted through a 2.8mm incision, the four-haptic implant incorporates an optic in its posterior wall and an enclosed space attached anteriorly with a circular opening that lines up with the capsulorhexis. This allows implantation of a piggyback lens inside the bag at a later date.
“Once it is inside the capsular bag it remains very stable,” Dr Quesada reported.
In a first-in-human study conducted in Dr Quesada’s surgery centre in San Salvador, El Salvador, the optic-spacer device was implanted in eight eyes of eight patients. Six months after surgery, four of the eight received piggyback lenses to correct residual refractive error and improve unaided visual acuity.
GOOD VISUAL OUTCOMES
Visual outcomes were good in all patients after implanting the experimental devices, which were all of the same refractive power, Dr Quesada said. Mean best-corrected distance visual acuity of the eight patients was logMAR +0.1, or 20/25, at one, three and six months after surgery.
Mild anterior iris surface trauma between the pupil and incision was noted in all eight cases. The trauma did not progress and appeared to be related to the initial insertion, Dr Quesada said.
Any standard IOL can be inserted into the device, and the four used in the study were easily implanted, Dr Quesada said. Uncorrected distance visual acuity in all four patients receiving the piggyback lenses was logMAR +0.13, or about 20/28, at one and three months after surgery.
The device maintained a large volume of space within the capsular bag throughout the duration of the study, Dr Quesada said. Anterior chambers were of a normal depth and shape in all cases at all postoperative visits including after piggyback IOL implantation.
“It was technically straightforward to implant this IOL/device within the capsular bag and implant a piggyback IOL within this device at six months post-op,” Dr Quesada said.
In clinical practice, Dr Quesada foresees the device being offered in a variety of powers to get as close to target as possible, with the option of dialling in refraction with a second piggyback lens when needed.