A Double Intraocular Lens Implant for Visual Rehabilitation of Patients with Macular Disease

Transcription

1 The IOL-Vip System A Double Intraocular Lens Implant for Visual Rehabilitation of Patients with Macular Disease Nicola Orzalesi, MD, 1 Chiara O. Pierrottet, MD, 1 Stefano Zenoni, MD, 2 Claudio Savaresi, MD 3 Purpose: To investigate the efficacy of a new surgical and rehabilitative procedure designed to improve vision in patients with central scotoma due to macular diseases. Design: Case series of 40 consecutive surgical and rehabilitative procedures. Participants: Forty eyes of 35 consecutive patients with a stable central scotoma due to macular disease underwent phacoemulsification cataract surgery with the implant of the IOL-Vip System. Methods: The IOL-Vip System consists of a biconcave high minus-power intraocular lens (IOL) in the capsular bag and a biconvex high plus-power IOL in the anterior chamber, reproducing an intraocular Galilean telescope with 1.3 magnification for distance. Selection of the candidate patients was carried out by means of a low-vision diagnostic and rehabilitative program (IOL-Vip software) that evaluates the residual visual function of patients and prognosis for visual improvement based on simulation of the postoperative condition. The software also designs the rehabilitation strategies based on preoperative and postoperative training of the preferred retinal locus. Main Outcome Measures: Best-corrected visual acuity (BCVA), evaluated by means of the Early Treatment Diabetic Retinopathy Study charts and procedure; reading magnification; and reading distance. Results: All patients showed an improvement of visual acuity (VA) due to the surgical and rehabilitative procedure, confirming or exceeding the preoperative expected results. Mean postoperative BCVA was 0.77 (logarithm of the minimum angle of resolution), compared with 1.28 preoperatively. The mean postoperative best reading magnification gain was 6.2, and the mean postoperative reading distance gain was 7.66 cm. No cases of intraoperative or postoperative complications were detected, and the implant was subjectively well tolerated in both monocular and binocular procedures. Conclusion: In this pilot study, the IOL-Vip System was shown to be effective and apparently well tolerated in improving the vision of patients with macular disease. Best-corrected VA, reading magnification, and reading distance improved in all cases of this low-vision patient series. Ophthalmology 2007;114: by the American Academy of Ophthalmology. The idea of implanting a magnifying intraocular device to improve visual function in patients with a central scotoma due to macular degeneration dates back to the Hanita Ben- Sira implant and the implantable miniature telescope. 1,2 The first is a bifocal optical implant with central hyperminus and peripheral positive components designed to be used in conjunction with specially constructed spectacles; however, its applications are limited by the difficulties in aligning the Originally received: July 14, Accepted: November 22, Manuscript no University Eye Clinic, San Paolo Hospital, Milan, Italy. 2 Eye Clinic, Ospedali Riuniti, Bergamo, Italy. 3 Ophthalmology Department, Clinica Santa Rita, Milan, Italy. Presented in part at: Association for Research in Vision and Ophthalmology annual meetings, April 2004 and April 2006 (poster session), Ft. Lauderdale, Florida. Correspondence and reprint requests to Nicola Orzalesi, Eye Clinic Director, University of Milan, San Paolo Hospital, Via A. di Rudinì 8, Milan, Italy. nicola.orzalesi@unimi.it. optical centers of the intraocular lens (IOL) and spectacle lens. Depending on the model, the magnification of the implantable miniature telescope is 2.2 or 3, which improves central vision but remarkably decreases the peripheral visual field (VF). As a result, one eye is used for seeing details and the other for purposes of orientation and mobility in a kind of monofield vision, which makes the device suitable only for unilateral implantation. Prismatic IOLs, which divert the focus to a preferred retinal locus (PRL), have also been implanted to improve vision in small series of patients with age-related macular degeneration (AMD). 3 Over the last 3 years, we have developed a new procedure (Video 1 [available at based on the implantation of a pair of intraocular lenses (IOL-Vip System, Soleko, Pontecorvo, Italy) that, in association with a dedicated rehabilitation program, offers new chances of improving vision in patients with central low vision due to macular conditions, thus increasing their autonomy in performing everyday living activities by the American Academy of Ophthalmology ISSN /07/$ see front matter Published by Elsevier Inc. doi: /j.ophtha

2 Orzalesi et al The IOL-Vip System Materials and Methods The IOL-Vip System consists of 2 IOLs that reproduce an intraocular Galilean telescope: a high minus-power biconcave IOL (about 66 diopters [D]) in the capsular bag acts as the eyepiece, and a high plus-power biconvex IOL (about 55 D) in the anterior chamber (AC) acts as the objective. Both lenses are made of polymethyl methacrylate, have a 1-piece design, and provide ultraviolet light filtering. The optic of the 2 lenses is 5 mm in diameter, with a maximum axial thickness of 1.5 mm for the AC IOL and peripheral thickness of 1.5 mm for the in-the-bag IOL; their total length is 13 mm. The haptics of the capsular bag and AC IOL are angled 7 anteriorly and 10 posteriorly, respectively (Fig 1). The system provides an estimated magnification for distance of 1.3, with the possibility of a small prismatic effect due to misalignment of the IOLs (as the direction and power of this effect are currently unpredictable, the possibility of using it to bring the image into a more favorable position with respect to the scotoma is still being investigated). The modulation transfer function of the system is The candidates for IOL-Vip implantation were selected using dedicated software that collects their clinical data, including bestcorrected visual acuity (BCVA) as evaluated by means of the Early Treatment Diabetic Retinopathy Study charts and procedure. The software (Invest Ophthalmol Vis Sci 45:abstract 2010-B821, 2004) may also be downloaded from or and provides a sort of campimetric examination to detect the position of the PRL spontaneously used during fixation, whose functional capability is established using the Fonda scheme for eccentricity of fixation. Based on the degree of eccentricity of the PRL, the software elaborates a series of 10 optotypes following a logarithmic scale in the range of the patient s visual acuity (VA). The aim of the preoperative and postoperative training program is to stimulate the PRL and, quite often, to force the patient to move it to a more favorable nearby position to cope with increasingly difficult visual tests. For this, the patients are presented with a series of flashing letters or flashing words whose size is gradually reduced and/or whose length is gradually increased, until the best performance is reached and stabilized. Letters or words are regularly changed to avoid any learning effect. A flashing method has been chosen to prevent patients from search movements during each presentation of the words and to promote quick glancing. Reading magnification and reading distance were also evaluated before surgery and at various times during follow-up. Reading magnification is the minimum magnification required for patients to read A.1 letters in the A-series scale (the size of newsprint) as given in Keeler s A-series near vision test charts. 4 Reading distance is the focal distance at which a patient has to hold the reading material for reading the appropriately magnified A.1 letters. We used the 500-lux illumination given by a lamp positioned beside or above the patient s head. All patients underwent 2-week preoperative training ( minute training sessions) and a 3-month postoperative rehabilitation program (5 30-minute training sessions per week for 12 weeks) aimed at training and consolidating the PRL. The software also records the everyday living activities that the patients would like to recover to assess the likelihood that the IOL-Vip procedure will meet their needs, thus reducing the development of unrealistic expectations. Before surgery, the patients undergo a simulation of the magnifying effect of the system using a 1.3 distance monocular Galilean telescope; at the end of the preoperative evaluation, the program provides a judgement of implant suitability that is used as a basis for obtaining their informed consent. Gain in VA was defined as the difference between the preoperative and postoperative logarithm of the minimum angle of resolution (logmar) values; the gains in reading magnification and reading distance were defined as the difference between preoperative and postoperative values. Initially, 71 patients with stable macular lesions were evaluated by means of the IOL-Vip software, 36 of whom were excluded as follows: (1) 39% refused to undergo what was then a very new surgical procedure; (2) 16% were pseudophakic in both eyes; (3) 13% had VA of 0.5 logmar in the fellow eye, and we were worried about causing problems with binocular vision; (4) 19% did not experience any improvement in VA using the simulator (these generally had very poor VA [ logmar]), made use of large search movements, and did not improve after the 2-week training); (5) 5% had corneal abnormalities, a low endothelial cell count ( 1600 cells/mm 2 ), and/or a shallow AC; and (6) 8% experienced satisfactory improvement in visual performance after simply following the preoperative PRL training program. The remaining 35 patients (16 males and 19 females years old) were considered suitable for the procedure and underwent phacoemulsification, followed by IOL-Vip implantation (Table 1 [available at in a total of 40 eyes with different forms of macular degeneration (33 with disciform scars or atrophic AMD, 4 with myopic macular degeneration, 1 with a longstanding and stable macular hole, 1 with a disciform scar in angioid streaks, and 1 with Stargardt s disease). Twenty-nine eyes had relatively clear lenses, whereas the remaining 11 had initial nuclear sclerosis and/or peripheral cortical opacities. A detailed preoperative fundus examination was possible in all cases. All patients had to be classified as having low vision (i.e., VA 0.5 logmar in both eyes). Mean preoperative BCVA was 1.28 logmar, mean preoperative best reading magnification was 9, and mean preoperative reading distance was 4.52 cm (Table 1). All of the operations were performed in an outpatient setting under local (29 cases) or topical (11 cases) anesthesia. Because of the thickness of the IOLs, the surgical protocol recommended a capsulorrhexis with a diameter of at least 6 mm to facilitate the implantation of the in-the-bag IOL, with the enlargement of the temporal corneal incision to up to 7 mm. One or two 10-0 nylon sutures secured the closure of the AC at the end of the procedure. The patients underwent preoperative neodymium:yttrium aluminum garnet (Nd:YAG) laser iridotomy or intraoperative peripheral iridectomy, preferably in a position that would not interfere with the implantation of the AC IOL haptics. The early postoperative follow-up examinations and medications did not differ from those normally scheduled in the case of routine phacosurgery. To assess the potential damage caused by the implant, all patients underwent an endothelial cell count before surgery and at the end of follow-up (mean duration, 20 months [range, 7 35]). Investigational review board approval was obtained, and the study was carried out in accordance with the principles laid down in the Declaration of Helsinki. Results The double IOL surgical procedure was well tolerated in all cases, and the follow-up did not substantially differ from that of normal phacosurgery using a single IOL implant (Fig 2). The same was true for the procedure-related endothelial cell loss of 7% (mean preoperative count, 2716; mean postoperative count, 2513), evaluated in 38 of 40 patients at the end of a mean follow-up of 20 months (range, 7 35). It is worth noting that the patient with the lowest preoperative count, 1783 cells/mm 2, showed a 10% loss (1603 cells/mm 2 ) 7 months after surgery, and the count in the case 861

3 Ophthalmology Volume 114, Number 5, May 2007 Figure 1. Front and side views of the in-the-bag (left) and anterior chamber (right) IOLs-Vip and front view of the IOL-Vip System into the eye at the end of the surgical procedure. with the longest follow-up went from 2035 to 1896 cells/mm 2 ( 7%) after 35 months. During the days after surgery, 3 of the first 5 cases developed a pupillary block with increased intraocular pressure (promptly managed by means of Nd:YAG laser iridotomy); because of this, preoperative iridotomy was performed in all of the other cases. One patient developed anterior capsule fibrosis and posterior capsular clouding 6 months after phacoemulsification, which was Figure 2. Slit-lamp view of the IOL-Vip System implanted into the eye 1 year after surgery. Perfect transparency of the cornea and a deep anterior chamber are evident. 862

4 Orzalesi et al The IOL-Vip System successfully managed by means of Nd:YAG laser capsulotomy. There were no severe complications such as corneal edema, iris and pupillary changes, excess inflammation and/or sepsis, macular edema, retinal detachment, glaucoma, or IOL displacement. All of the patients completed the 3-month rehabilitation program established by the software and were examined by a low-vision specialist every 3 months after surgery. As a consequence of the training program, 35 eyes (87.5%) moved their PRL to a more favorable position, as shown by the improvement of visual performance. Two eyes (5%) had spontaneously developed the best PRL, which did not change during the preoperative and postoperative training. The remaining 3 eyes (7.5%) (with very poor preoperative VA) had an unstable and peripheral PRL, with large search movements that did not change with the rehabilitation training. Despite this, they were enrolled in the study, as they had some visual benefit from the preoperative simulation of the magnifying effect. The improvement in VA is shown in Figure 3 and Table 1 (available at The eyes were arbitrarily divided into 2 groups because of their different preoperative VAs: 28 patients with very poor VA ( 1.1 logmar) and 12 with relatively good preoperative VA ( 1.0 logmar). In the first group, mean postoperative BCVA was 0.87 logmar (compared with 1.47 logmar preoperatively); mean preoperative best reading magnification was 11.6, which decreased to 3.5 (a gain of 8.1); and preoperative best reading distance was 2.66 cm, which increased to 8.21 cm (a gain of 5.55 cm). The second group of 12 patients had relatively good preoperative VA ( 1.0 logmar). In the second group, mean postoperative BCVA was 0.50 logmar (compared with 0.85 logmar preoperatively); their mean preoperative best reading magnification was 3, which decreased to 1.3 (a gain of 1.7); and their preoperative best reading distance was 8.87 cm, which increased to cm (a gain of cm). The reason for the larger number of patients in the first group was concerns about Figure 3. Scattergram showing improvement in visual acuity (VA) in 40 eyes (5 binocular and 30 monocular cases) after surgical implantation of the IOL-Vip System. Preoperative (pre-op) and postoperative (post-op) best-corrected VAs (BCVAs) were measured by means of Early Treatment Diabetic Retinopathy Study charts, after a 2-week and a 3-month rehabilitation program, respectively. logmar logarithm of the minimum angle of resolution. the safety of the procedure, which meant that only eyes with very severe low vision ( logmar) were initially selected. The postoperative changes in distance BCVA plotted in Figure 3 show that all of the cases experienced a gain, which was sometimes remarkable (mean postoperative BCVA of the 7 bestperforming cases was 0.42 logmar, as against mean preoperative BCVA of 0.84 logmar). The severe low-vision cases in the first group also benefited: most of them had had to abandon reading completely but could resume it after implantation (albeit with low-vision aids), and the majority improved in watching television, recognizing money, and sewing. All of this was reported as improving their quality of life. The eyes with mild lens opacity were also evaluated separately from those with clear lenses: VA of 11 cases in the former group went from 1.26 to 0.76 logmar, and that of 1 case in the latter group from 1.29 logmar to 0.76 logmar. The IOL-Vip System was subjectively well tolerated and did not seem to limit the peripheral VF or interfere with binocular vision. Most of the patients retained or improved their mobility and orientation, thus making the double surgical/rehabilitation procedure suitable not only for the 5 binocular cases, but also for the monocular cases and patients who had previously undergone felloweye cataract surgery (12 patients). Discussion There are various hereditary or acquired retinal disorders that give rise to macular degeneration, of which AMD is very frequent and the leading cause of legal blindness in developed countries. However, despite the frequency of these diseases the available treatments cannot prevent severe central vision loss in most cases, and impaired foveal function reduces patients ability to carry out everyday activities such as reading, writing, or grooming. Although most patients retain sufficient visual function to perform activities such as walking that do not require seeing details, macular diseases are a leading cause of anxiety, depression, and trauma in old age, with public health services carrying most of the burden. 5 8 Patients may take advantage of magnification-based lowvision aids that bring the object closer to the eye and increase the angle of resolution. All types of magnifying aids may be useful for near vision (hand and stand magnifiers, stronger correction telescopes, and closed-circuit television), but for distance vision, the choice is limited to telescopes and headset closed-circuit television, both of which have a low cost/benefit ratio and generally lead to patient frustration and abandoning of the device. The main reasons for this are the reduced field of vision, need to have the object nearer, and impractical nature of telescopes and headset closed-circuit television. Intraocular magnifying telescopes, such as the implantable miniature telescope, have also been tried, 9,10 but once again, their limited VF and prevention of binocular vision reduce patient satisfaction. Because of the typical age of patients with macular degeneration, many also have varying degrees of lens opacity and, although it is not strictly needed at that time, may usefully undergo cataract surgery in association with IOL- Vip implantation. When considering the visual results of the IOL-Vip procedure, the effect of removing a relatively clear lens must be taken into account, as it could contribute to the 863

5 Ophthalmology Volume 114, Number 5, May 2007 success of the procedure and its role may therefore be subject to discussion. However, its impact on the visual functions of our patients can be considered negligible for a number of reasons: 1. The discrepancy between a very severe macular lesion justifying very low vision in comparison with faint lens opacity and the considerable postoperative gain in VA. 2. Twelve of our patients had undergone previous cataract surgery in the fellow eye, whose lens opacity was similar to or worse than that of the eye implanted with the IOL-Vip System. The visual improvement was from 1.28 to 1.08 logmar in the eyes undergoing cataract surgery but from 1.28 (a coincidence) to 0.7 logmar in the case of the implanted eyes, and patient satisfaction with the second was as enthusiastic as the satisfaction with the first had been scanty. 3. The good result in the 29 patients with relatively clear lenses could not be due to lens removal alone, and the behavior of this group did not differ from that of the 11 with faint lens opacities: mean postoperative BCVA in the 29 eyes with clear lenses was 0.76 logmar, against a preoperative value of 1.29 logmar, whereas, in the 11 eyes with initial nuclear sclerosis and/or peripheral cortical opacities, the corresponding figures were 0.76 and 1.26 logmar. The effect of removing lens opacity cannot be completely ruled out in all cases of the IOL-Vip implant, but it is worth considering that increasing experience of this procedure and its advantages could lead to the main indication for IOL-Vip implantation in patients with central low vision and a clear lens regardless of cataract surgery. On the basis of our results, we arbitrarily divided our patients into 2 groups: severely low vision ( 1.1 logmar) and mildly low vision ( 1.0 logmar). We initially selected patients with very severe low vision because, again, we were concerned about the safety of the surgical procedure, but as we became increasingly confident, we extended the indication to mild cases of low vision. The best results were achieved in the second group as the patients recovered their ability to perform daily activities such as reading, but also in the first group reading often became possible (albeit with low-vision aids), as well as watching television, recognizing money, and sewing. In general, this corresponded in both groups to a definite improvement of quality of life and satisfaction for the surgical intervention. The low optical magnifying power of the IOL-Vip System allows the maintenance of the peripheral VF and possibility of comfortable binocular vision, thus making it suitable for monocular or binocular implantation. Unlike external telescopes, intraocular implants follow naturally occurring eye movements, and this is a major advantage. The improvement in distance VA reduces the amount of magnification needed for near vision, which leads to better and more comfortable reading. This is also favored by the increased reading distance, which helps to satisfy the aim of making IOL-Vip implanted eyes similar to those of people with normal sight. Our patients with more severe lesions experienced only a slight improvement in VA (from 1.7 to 1.0 logmar), but the system may in any case allow better vision and a better response to conventional low-vision aids. Among the limited number of patients who have so far undergone the procedure, the greatest improvements in VA were obtained in eyes with well-circumscribed macular lesions (such as a stable macular hole or small atrophic areas), as in such cases normal paramacular photoreceptors are likely to support the rehabilitation process. The visual improvement recorded preoperatively during the simulation of the magnification was seen as the most critical predictive factor of success. We did not apply any rigid exclusion criteria based on lesion size or shape, but the presence of a PRL that was too far from the fovea and/or did not adequately respond to presurgical rehabilitation was considered a relative contraindication. The procedure was also considered unsuitable for patients with ocular diseases that can reduce the peripheral VF (e.g., glaucoma, retinitis pigmentosa), patients with an axial length of 20 mm, and those judged to be unlikely to adhere to the postoperative rehabilitation program. The IOL-Vip implant has so far not led to any significant serious adverse events, with the exception of pupillary block glaucomas in 3 of the first 5 patients, a problem that was solved by adopting preoperative Nd:YAG laser iridotomy in all subsequent cases. No severe complications have been observed, and endothelial cell counts had decreased by only 7% at the end of a mean follow-up of 20 months. This was a pilot study of a new surgical procedure, and it is premature to make any comments concerning safety because of the limited number of patients and duration of follow-up. However, it does seem reasonable to point out that the complications associated with the IOL-Vip procedure did not exceed those of routine phacoemulsification (Fig 2). Given the size of the 2 IOLs, there may be concerns about the space they occupy in the anterior segment of the eye and their proximity to critical ocular structures such as the corneal endothelium and iris. One possible explanation of the good fitting of the double implant in the anterior segment of the eye, and the maintenance of a sufficient distance from the corneal endothelium and anterior surface of the biconvex IOL (Fig 2), is the complementary convex/ concave surfaces of the 2 IOLs (the axial thickness of the convex IOL is 1.5 mm, but that of the concave IOL is only 0.4 mm), which actually reduce the theoretical space needed for the implant. Moreover, in the absence of a cataractous lens the relatively rigid anteriorly angled concave IOL may slightly displace backward the zonules posterior capsule diaphragm, thus increasing the space available for the implant. However, it is true that the space occupied by the double implant in the anterior segment of the eye make a shallow AC, exceedingly low endothelial cell count, and/or guttata obvious contraindications. One point that deserves attention and further investigation is that the visual improvement experienced by some patients was greater than that predicted, and some discrepancy exists between the optical model and results obtained in practice. It is likely that optical rules become more flexible in living eyes, and so some patients may experience a greater improvement than that originally predicted: one 864

6 Orzalesi et al The IOL-Vip System example is the case of myopic eyes, whose greater axial length makes it possible to increase the distance between the 2 IOLs, with a consequent increase in magnification. This actually happened when visual performance was tested after surgery and, of course, was much appreciated by those patients. Some ancillary aspects of the project (prismatic effect of the IOLs, training) are not completely understood for the moment and/or need a long and detailed explanation. They may be considered secondary with respect to the originality of the procedure, whose efficacy is based, first of all and without any doubt, on the implant of a new magnifying device allowing comfortable vision after a simple and well-tolerated surgical procedure. We implanted the first IOL-Vip System in December 2002; since then the procedure has been successfully used by a number of other ophthalmologists, and its use is expanding in Italy, Spain, and the United Kingdom. By the time this article is published, it is expected that more than 200 cases will have been treated in this way. References 1. Mayer A. Clinical experience with the Ben-Sira teledioptric system for use in age-related macular degeneration. Ger J Ophthalmol 1996;5: Lipshitz I, Lowenstein A, Reingewirtz M, Lazar M. An intraocular telescopic lens for macular degeneration. Ophthalmic Surg Lasers 1997;28: Piggiback implantation of new prismatic IOL can improve visual functioning in ARMD patients, French pilot study suggests. Eurotimes 2001 Jan/Feb: Dowie AT. Management and Practice of Low Visual Acuity. London: Eastern Press; 1988: Klein BE, Klein R, Lee KE, Cruickshanks KJ. Performancebased and self-assessed measures of visual functions as related to history of falls, hip fractures, and measured gait time: the Beaver Dam Eye Study. Ophthalmology 1998;105: Williams RA, Brody BL, Thomas RG, et al. The psychosocial impact of macular degeneration. Arch Ophthalmol 1998;116: Chia EM, Wang JJ, Rochtchina E, et al. Impact of bilateral visual impairment on health-related quality of life: the Blue Mountains Eye Study. Invest Ophthalmol Vis Sci 2004;45: Cahill MT, Banks AD, Stinnett SS, Toth CA. Vision-related quality of life in patients with bilateral severe age-related macular degeneration. Ophthalmology 2005;112: Lipshitz I, Sadeh AD, Loewenstein A. The implantable miniaturized telescope for patients with age-related macular degeneration: design and surgical technique. Oper Tech Cataract Refract Surg 2000;3: Lane SS, Kuppermann BD, Fine IH, et al. A prospective multicenter clinical trial to evaluate the safety and effectiveness of the implantable telescope. Am J Ophthalmol 2004;137:

7 Table 1. Demographics of the 35 Patients (40 Eyes) and Preoperative and Postoperative Best-Corrected Visual Acuity (BCVA) Measured by Means of Early Treatment Diabetic Retinopathy Study Charts, after 2 weeks and 3 Months Rehabilitation Programs, Respectively Eye Age Gender Diagnosis Ophthalmology Volume 114, Number 5, May 2007 Preoperative BCVA (logmar) Postoperative BCVA (logmar) Best Reading Magnification Preoperative for Reading Postoperative for Reading Gain Preoperative Reading Distance (cm) Postoperative Reading Distance (cm) Reading Distance Gain (cm) 1 65 M AMD M AMD F AMD M AMD F AMD M AMD F AMD F AMD M AMD M AMD F AMD F AMD M Stargardt s disease F AMD F AMD F AMD M Macular hole F Angioid streaks M AMD F AMD F AMD F AMD M Myopia F AMD F Myopia F AMD F AMD M AMD M Myopia M Myopia * 72 F AMD * 72 F AMD * 68 F AMD * 68 F AMD * 75 M AMD * 75 M AMD * 73 M AMD * 73 M AMD * 78 M AMD * 78 M AMD AMD age-related macular degeneration; F female; logmar logarithm of the minimum angle of resolution; M male. *Patient with binocular IOL-Vip implant. 865.e1