Posters

Visual performance evaluation of a new multifocal intraocular lens design before implantation

Poster Details

First Author: M.Aldaba SPAIN

Co Author(s):    M. Aldaba   A. Giner   J. Güell   J. Pujol     

Abstract Details

Purpose:

To assess the visual performance before surgery of a new multifocal intraocular lens design by means of a vision simulator, and compare it with other commercial IOL.

Setting:

Centre for Sensors, Instruments and Systems Development of the Universitat Politècnica de Catalunya, Terrassa, Spain.

Methods:

The loss of accommodating ability in pseudophakic patients is a problem after the cataract surgery. Several solutions have been proposed to restore the ability of seeing near objects after surgery and one of them is the use of multifocal intraocular lenses (MIOL). Appeared in the late 1980s, several MIOLs designs have been developed and its use has increased in the last years. One of the strongest points of the MIOLs is enabling far and near clear vision. On the other hand, the drawbacks are halos, reduced contrast sensitivity and adaptation problems. The implantation of an IOL is not irreversible, but the extraction and new IOL implantation is rare as implies new surgery. Thus, the evaluation of visual performance of an IOL before implantation is of great interest. Recently a new instrument (VirtOL, 101Lens S.L.U.) that simulates the vision through the IOL before surgery, has been developed. Taking advantage of the VirtIOL the visual performance of a new MIOL design (NDIOL, OPHTEC prototype), is evaluated and compared with a monofocal IOL (monIOL, used as a reference) and a commercial MIOL (MPlus, Oculentis®). In vivo visual performance was evaluated when seeing through IOLs using the VirtIOL. Visual acuity (VA) and subjective perception were evaluated during a throughfocus scanning from far vision (FV) to near vision (NV), in 0.50D steps. Subjective perception was measured in terms of perception of halos and double vision, ranging from 0 (null) to 3 (maximum). Contrast sensitivity (CS) was also evaluated for contrasts of 100%, 25% and 10%, for far and near vision. 5 presbyopic patients were enrolled in the study, with mean age of 53.2±6.7 years, amplitude of accommodation lower than 1D and best corrected VA of -0.09±0.09 in logMAR units. Three multifocal IOLs were tested: NDIOL-FC (OPHTEC Prototype) Add= 2,75D with the central zone corresponding to far refraction; NDIOL-NC (OPHTEC Prototype) Add= 2,75D with the central zone corresponding to near refraction; Lentis M-Plus Add = +3.00D (Oculentis®); and a monofocal IOL was used as reference. All the measurements were performed by the same operator and were repeated 3 times.

Results:

In FV conditions the best VA was obtained, as expected with the monofocal IOL (-0.06±0.09). MIOL lenses show similar values, being the MPlus a little bit higher (-0.03±0.10) than NDIOL-CF (0.04±0.14) and NDIOL-CN (0.05±0.11). In near vision, the best VA was obtained with the NDIOL-CF (0.03±0.11) followed by MPlus (0.06±0.11 ), NDIOL-CN (0.19±0.18 ) and, as expected, by the monofocal IOL (0.57±0.05 ). The throughfocus scanning showed that the MPlus lens has a more marked bifocal behaviour than the NDIOL lens. This behaviour consists on an accommodative curve with well identified peaks of a good VA in FV and NV and a decreased VA at intermediate vision (distance = 1m). The difference in VA between FV andintermediate was of 0.23±0.11 for MPlus lens; 0.16±0.09 for NDIOL-CN and 0.12±0.07 for NDIOL-CF. No differences were found in the perception of halos and double images between the MIOL lenses evaluated. The MIOLs evaluated show a similar reduction on visual acuity with contrast with a reduction of about two lines when contrast was reduced from 100% to 10%.

Conclusions:

In vivo visual performance of three MIOLs has been evaluated before surgery using a visual simulator (VIRTIOL). The lenses analysed showed a good VA for FV and NV. During the throughfocus scanning MPlus lens show more marked bifocal lens behaviour than both NDIOL lenses, which becomes revealed by a more important decrease of the VA at intermediate vision compared with VA for FV and NV. Subjective perception of halos and double image is similar for all the MIOLs evaluated and similar decrease of VA when the contrast decreases. FINANCIAL INTEREST: One of more of the authors... research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented, One of more of the authors... travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented