comparison of visual outcomes after implantation of the pod ft and the pod f

Conditions: Cataract

Summary: there is no difference of the photic phenomena in the two groups. the study will be a prospective non-randomised controlled study. the target is then to determine the equivalence in the glare. assumption of type i error is p=0.05 as level of significance and type ii error is alpha=0.8 as power.

the study will be a prospective non-randomised controlled study. the target is then to determine the equivalence in the glare. assumption of type i error is p=0.05 as level of significance and type ii error is alpha=0.8 as power. we used the 'trialsize' package of the r software. here are the parameters defined for the sample size calculation: 1. alpha: 0.05 2. power : 0.90 3. two sided test 4. equal group allocation 5. standard deviation for the two groups (pod 26p ay f et pod 26p ay ft) equal to 0.10 6. expected mean for the two groups (pod 26p ay f et pod 26p ay ft) equal to 0.89 (true difference between the means equal 0) 7. an equivalence limit of 0.05, 0.10 and 0.15 equivalence limit: 0.15 in order to show no difference between these two groups, 12 patients by groups are needed. with a drop-out of 15%, we obtain 30 patients (15 patients by group) to recruit in order to obtain 24 valuable patients. equivalence limit: 0.10 in order to show no difference between these two groups, 26 patients by groups are needed. with a drop-out of 15%, we obtain 62 patients (31 patients by group) to recruit in order to obtain 52 valuable patients. this total number of subjects with such requirement is 26 patients in each group. group 1 will be made of 26 patients with corneal astigmatism higher than 1.0d in both eyes and lower than 2.5d and will be implanted with the pod 26p ay ft and group 2 will be made of 26 patients with corneal astigmatism lower than 1.0d in both eyes. interim analysis after the 12th patient of each group will have completed the last follow-up will be achieved to confirm the equivalence with the equivalence limit of 0.15. the pod platform in 26 % (non toric version) is available since 2008 in the monofocal version and since 2012 in the toric one (pod 6p ay t, ankoris®, physiol).the so-called pod design is characterised by two symmetrical bifid haptics with opened loops that provide four points of support to ensure iol stability in the capsular bag. the dual c-loop profile shortens the loops, thus improving the pliability of the implant during its injection through a micro-incision. these shortened loops should permit a clockwise or anticlockwise rotary motion and should facilitate the comfortable fitting of the implant orientation after unfolding without elastic-restoring torque. the double c-loop pod design offers 4 support points for the implant within the capsule and ensures its stability. the v-shape of the upper and lower haptics together with the flexibility of the implant allow the loop separation angle to be adjusted and ensure the most accurate adaptation to the capsular bag size. a finite element structural analysis of the implant showed that the elasticity at the distal part of the loop prevents the constraints from being transmitted onto the optical portion of the implant. the trifocal optic is associated to the pod platform and is made of 26 % raw material. the rotational stability of this non toric version has been clinically investigated on 117 consecutive eyes 1 week, 3 weeks, 3 and 12 months after implantation. the absolute rotation of the lens averaged 2.5 ± 2.6°. the position of the center of the implant relative to the pupillary center expressed by a vector was 0.01 mm at 70°. the investigational product (pod 26p ay ft) is ce labeled since january 2014. main iol features are: * biconvex toric aspheric (-0.11um sa) blue-blocking, hydrophilic acrylic iol with 26% equlibrium water content, implantable through ≥ 2.2mm incision. * 4-point haptic design * 6 mm of optical diameter / 11.4 mm of total diameter * dioptric range (se): 6 to 35 d by 0.5 d increments * cylinders at the iol plane: 1, 1.5, 2.25, 3, 3.75, 4.5, 5.25, 6 d * addition +1.75d / +3.5 d the control product (pod 26p ay f) is ce labeled since 2010. main iol features are: * biconvex, aspheric (-0.11um sa) blue-blocking, hydrophilic acrylic iol with 26% equlibrium water content, implantable through ≥ 2.2mm incision. * 4-point haptics design which minimizes decentration and optimizes the rotational stability * 6 mm of optical diameter / 11.4 mm of total diameter * dioptric range (se): 6 to 35 d by 0.5 d increments * addition +1.75d / +3.5 d

Eligibility criteria:
inclusion criteria: * age-related cataract * preoperative corneal astigmatism \< 0.75 d * age 21 and older * visual acuity \> 0.05 * normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant. * patient willing multifocal implantation and with realistic expectations. exclusion criteria: * relevant other ophthalmic diseases such as pseudoexfoliation syndrome, floppy iris syndrome, corneal pathologies, retinal pathology (diabetic maculopathy, myopic maculopathy, age related macular degeneration...) * previous ocular surgery or trauma.

Keywords: hydrophilic toric intraocular lens cataract trifocal bvi medical