Optical and visual quality of spheric and toric Artiflex. A pilot study

Poster Details

First Author: C.Peris Martinez SPAIN

Co Author(s):    Mª Carmen Gracia-Domene   Mª Amparo Diez-Ajenjo   JM Artigas    JL Menezo      

Abstract Details

Purpose:

To analyze and compare the optical and the visual quality of a phakic iris fixation intraocular lens (Artiflex), in both versions, spheric and toric.

Setting:

Cornea and Refractive Surgery Unit. Fundación Oftalmológica del Mediterrįneo (FOM), Valencia, Spain.

Methods:

Modulation Transfer Function (MTF) of both lenses was measured the with the OPAL Vector System at three different pupil diameters (3, 4 and 5 mm). We analyzed the modulation at 100 c/mm and the average modulation (AM) of 26 eyes of 13 patients with bilateral implantation. In 18 eyes we implanted a spheric version of Artiflex lens (SAL) and in the other 8 eyes we implanted a toric version of Artiflex lens (TAL). Follow-up period 1 year. We measured in preoperative visit, the optic compensation, uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA, endothelial cell count (ECC), intraocular pressure (IOP), and keratometry with Pentacam. The postoperative outcomes were the same measurements and we added the contrast sensitivity function (CSF) at photopic (85 cd/m2) and mesopic (4 cd/m2) illumination conditions with the CSV-1000 test.

Results:

The modulation at 100c/mm was 12+1 for SAL and 22+3 for TAL, both of them independent of the pupil diameter. The AM was 0.366, 0.352 and 0.308 for SAL and 0.519, 0.477 and 0.426 for TAL at 3, 4 and 5 mm respectively. Mean age was 34+8 years old. Spherical equivalent previous surgery was -10+3 D in SAL and -9+3 D in TAL. Cylinder compensation was -0.4+0.2 D in SAL and -2.6+0.9 D in TAL. In both lenses the postoperative ECC decreased slightly, but not with statistical differences. Mean ECC was 2539+375 c/mm2.The preoperative BCVA was 0.04+0.1 for SAL and 0.2+0.1 for TAL. Postoperatively, BCVA was 0.04+0.06 for SAL and 0.09+0.18 for TAL. We not found statistical differences between both lenses in BCVA postoperatively, but we found differences in BCVA between preoperative and postoperative measure in TAL (p=0.016). CSF in mesopic conditions was worse than CSF in photopic conditions in both lenses, and we obtained the photopic and mesopic CSF of TAL more diminished than in SAL, however, neither difference was statistically significant.

Conclusions:

Optic quality, measured by MTF and evaluated by the AM, diminished with pupil diameter, in SAL about a 15% and in TAL about 18% between 3 and 5 mm. However, between both lenses, we found a decrease of AM in spheric version of 29.5% respect toric lens, but, these differences were not enough to affect visual acuity of our patients. At one year, both groups obtained similar BCVA and, although we observed a slight tendency of worse CSF in photopic and mesopic conditions at high spatial frequencies in toric lens, we need more measurements with more patients to confirm this result. The contradiction that we found between optical quality (it is better in toric lens than in spherical lens) and the visual quality of patients (it is better in spherical lens) can be explained by the rotation of the axis in toric lens. The differences between BCVA previously and 1 year after surgery in toric lens indicates that although small deviations, Artiflex toric is a good choice for compensate these kind of patients. FINANCIAL DISCLOSURE?: No