1. Long-term results of Phakic Refractive Lens (PRL™) implantation in high myopic eyes. Ioannis G. Pallikaris 1, 2, MD, PhD, Maria I. Kalyvianaki 1, MD, PhD, Dimitra M. Portaliou, MD, Sophia I. Panagopoulou 1, PhD. 1University of Crete, Medical School, Vardinoyannion Eye Institute of Crete, Greece. 2University Hospital of Heraklion, Department of Ophthalmology, Crete, Greece. The authors have no financial or proprietary interest The authors have no financial or proprietary interest in any materials or methods described herein in any materials or methods described herein

2. Abstract Purpose: To evaluate the long-term efficacy, predictability and safety of phakic refractive lens (PRL™, Carl Zeiss Meditec) implantation in high myopic eyes. Setting: Department of Ophthalmology, Medical School, University of Crete, Crete, Greece. Methods: 136 myopic eyes of 78 patients were treated for high myopia with the implantation of the silicone phakic refractive lens (PRL™) in the posterior chamber. Mean patients’ age was 28.59±6.13years (range 18 to 44 years). Manifest refraction in spherical equivalent (MR), uncorrected (UCVA), best-corrected (BCVA) visual acuity (decimal scale), intraocular pressure, possible complications and subjective symptoms were evaluated. Results: Mean follow-up was 3.82+ 1.93 years (range 6 months to 7 years). Two years after the treatment (N=62) there was a statistically significant reduction in the MR [pre-PRL: -14.00D+4.18D (-26.00D to -5.00D) to -0.16D+0.43D (-2.25D to 1.00D) (p<0.001). 75 (55%) and 109 eyes (80%) were within +0.50 D and +1.00 D of target refraction respectively. Mean UCVA significantly (p<0.001) improved [pre-PRL: counting fingers preoperatively in all eyes to 0.79+0.27 (0.2 to 1.2). Mean BCVA also improved from 0.71+0.24 (0.10 to 1.00) to 0.87+0.27 (0.40 to 1.20) (p<0.001). Up to seven years postoperatively no treated eyes presented any signs of cataract. Conclusion: Long-term results showed that PRL™ implantation was an effective and safe method for treating high myopia.

3. The Phakic Refractive Lens (PRL™) is a posterior chamber lens developed by Medennium Inc. It is made of silicone with high refractive index (1, 46), which allows its ultra thin design. PRL™ is not supported in the sulcus angle, but it floats in the posterior chamber over the crystalline lens, due to its hydrophobic material (Figures 1a,b). Its cent ration is achieved by its self-centering design. The one-and two-year clinical results of PRL implanted eyes suggest that it is efficient and predictable for the treatment of high myopia and hyperopia 1-5. However, longer follow-up is mandatory, in order to evaluate its safety and stability. The purpose of our study was to evaluate the long- term efficacy, predictability and safety of phakic refractive lens (PRL™, Carl Zeiss Meditec) implantation in high myopic eyes. Introduction Figure 1a Figure 1b

4. Materials and methods 136 myopic eyes of 78 patients were treated with PRL™ implantation by the same surgeon (IGP). Mean patients’ age was 28.59±6.13years (range 18 to 44 years). Preoperative evaluation included manifest refraction in spherical equivalent (MR), uncorrected (UCVA), best-corrected (BCVA) visual acuity (decimal scale), intraocular pressure, slit lamp microscopy, pupil size measurement under scotopic conditions, white to white corneal diameter measurement with the use of a caliper, dilated fundoscopy and A-scan ultrasonography (Axis-II, Quantel Medical ). PRLs were inserted with the use of special forceps. At the end of the procedure a surgical iridectomy was performed with the use of a vitreotome in 72 eyes, while two YAG-laser iridotomies were performed 1 week before the procedure in 64 eyes. Mean follow-up was 3.82+ 1.93 years (range 6 months to 7 years).

5. Results Efficacy Mean UCVA significantly improved from counting fingers preoperatively in all eyes to 0.79 (N=62, decimal scale) at the 2 year follow up examination Mean UCVA significantly improved from counting fingers preoperatively in all eyes to 0.79 (N=62, decimal scale) at the 2 year follow up examination

6. Results Safety Compared to the preoperative value, 78% of eyes (106) gained 1 to 4 lines of BCVA

7. Results Stability Refractive results remained stable during the six-year follow-up

8. Results Predictability At two years 34 (55%) and 50 eyes (80%) were within +0.50 D and +1.00 D of target refraction respectively.

9. During surgical iridectomy with the probe of a vitreotome, 3 eyes experienced damage of the anterior capsule of the crystalline lens.During surgical iridectomy with the probe of a vitreotome, 3 eyes experienced damage of the anterior capsule of the crystalline lens. In fourteen eyes (10%) a statistically significant increase in IOP was found during the 1st month post-op. IOP returned to preoperative levels at three months (6 patients were corticosteroid responders).In fourteen eyes (10%) a statistically significant increase in IOP was found during the 1st month post-op. IOP returned to preoperative levels at three months (6 patients were corticosteroid responders). Rotation of the PRL was noticed in many cases with no consequences.Rotation of the PRL was noticed in many cases with no consequences. One eye had pigment dispersion, high IOP and PRL extraction 3 years postop due to reverse PRL implantation.One eye had pigment dispersion, high IOP and PRL extraction 3 years postop due to reverse PRL implantation. There was one case of PRL decentration and PRL extraction 3 years postop (Figure 2).There was one case of PRL decentration and PRL extraction 3 years postop (Figure 2). No PRL was lost in the vitreous No PRL was lost in the vitreous No eye presented cataract during the 7-year follow-upNo eye presented cataract during the 7-year follow-up Complications Figure 2

10. Complications Figure 3 Slitlamp photograph of patient 3 months after PRL implantation shows focal opacity behind iridectomy because of damage to the anterior capsule. Opacification remained focal behind the iridectomy and did not progress to cataract in the visual axis Figure 4 Pallikaris) Slitlamp photograph shows anterior subcapsular opacification 1 year post-PRL implantation. No progression or loss of BCVA was noted. (Pallikaris) Slitlamp photograph shows anterior subcapsular opacification 1 year post-PRL implantation. No progression or loss of BCVA was noted.

11. Long-term results suggest that PRL is an effective, predictable, stable and safe method for the treatment of high myopia. However, further follow-up and additional patients must be reviewed to draw final conclusions about the efficacy and safety of this lens. Moreover, preoperative and postoperative endothelial cell count would be indicative of the percentage of endothelial cell loss after PRL implantation. Discussion

12. References 1.IG Pallikaris, MI. Kalyvianaki, GD Kymionis, SI Panagopoulou. Phakic Refractive Lens (PRL™) implantation in high myopic patients: One- year results. J Cataract Refr Surg 2004; 30:1190-97. 2.Jongsareejit A. Clinical results with the medennium phakic refractive lens for the correction of high myopia. J Refract Surg 2006; 22:890-7. 3.Koivula A, Petrelius A, Zetterström C. Clinical outcomes of phakic refractive lens in myopic and hyperopic eyes: 1-year results. J Cataract Refract Surg 2005; 31:1145-52. 4.Koivula A, Taube M, Zetterström C. Phakic refractive lens: two-year results. J Refract Surg 2008; 24:507-15. 5.Verde CM, Teus MA, Arranz-Marquez E, Cazorla RG Medennium posterior chamber phakic refractive lens to correct high myopia. J Refract Surg 2007 ;23:900-4