Comparison of Two ICLS

INTRAOCULAR PRESSURE AFTER IMPLANTATION OF THE VISIAN IMPLANTABLE COLLAMER LENS WITH CENTRAFLOW WITHOUT IRIDOTOMY

Higueras-Esteban A, Ortiz-Gomariz A, Gutiérrez-Ortega R, et al¹

Abstract summary. Higueras-Esteban et al retrospectively compared intraocular pressure (IOP) after implantation of the Visian Implantable Collamer Lens (Visian ICL; STAAR Surgical) V4c and V4b designs in 17 and 18 eyes, respectively, over a 3-month period. The presence of a central 360-μm hole, the KS-Aquaport, differentiates the V4c (hole ICL; Figure 1) from the V4b (conventional ICL; Figure 2). According to the company, its KS-Aquaport Centraflow technology allows a more natural flow of aqueous humor, eliminating the need for a laser iridotomy or surgical iridectomy.

The investigators implanted the IOLs between September 2011 and May 2012. Eyes in the conventional ICL group received two Nd:YAG laser iridotomies 2 weeks before surgery.

Three months postoperatively, the mean logMAR distance UCVAs in the hole and conventional ICL groups were -0.07 ±0.11 and -0.09 ±0.12, respectively. One or more lines of distance BCVA were gained in 44.4% of eyes in the hole ICL group versus 52.9% of eyes in the conventional ICL group. According to the study, only one of 35 eyes did not achieve an outcome within ±0.50 D of the target refraction.

The mean IOP showed a mild transient increase during the first month in both groups, from 11.9 ±2.7 and 11.5 ±2.8 mm Hg preoperatively in the hole and conventional ICL groups, respectively, to 13.8 ±2.2 and 12.4 ±1.8 mm Hg 3 months postoperatively, respectively. There was no significant difference between pre- and postoperative IOP values. At 3 months, the mean vault was 528 ±268 μm (95% CI, 354–635 μm) in the hole ICL group and 557 ±224.4 μm (95% CI, 442–672 μm) in the conventional ICL group (P =).73). There were no significant differences in IOP within or between groups during follow-up (P >.05 for all comparisons).

On a subjective questionnaire, five patients in the hole ICL group reported transient increases in halos in the early postoperative period that significantly decreased by 1 month after surgery.

VISUAL QUALITY COMPARISON OF CONVENTIONAL AND HOLE-VISIAN IMPLANTABLE COLLAMER LENS AT DIFFERENT DEGREES OF DECENTERING

Pérez-Vives C, Ferrer-Blasco T, Madrid-Costa D, et al²

Abstract summary. Pérez-Vives et al used an adaptive optics visual simulator (crx1; Imagine Eyes) to simulate and compare the visual acuity provided by conventional and hole ICLs at different refractive powers (-3.00, -6.00, and -12.00 D) and at different degrees of decentration (centered, decentered by 0.3 mm, and decentered by 0.6 mm) in the presence of 3- and 4.5-mm pupils in one eye of 15 patients. According to the authors, this method allows evaluation of visual quality without the need for Visian ICL implantation as well as analysis of the effect of each Visian ICL model and its decentering effects. The investigators measured contrast sensitivity and high-, medium-, and low-contrast visual acuities for three spatial frequencies: 10, 20, and 25 cycles/degree.

According to the investigators, the simulation did not reveal a significant difference in visual acuity or contrast sensitivity between the two groups at any ICL power, decentered position, pupillary size, or spatial frequency.

COMPARATIVE STUDY OF TWO TYPES OF IMPLANTABLE COLLAMER LENSES; ONE WITH AND ONE WITHOUT A CENTRAL ARTIFICIAL HOLE

Huseynova T, Ozaki S, Ishizuka T, et al³

Abstract summary. Huseynova et al compared the outcomes between hole (n=44 eyes) and conventional ICLs (n=21 eyes) after implantation. The investigators examined patients pre- and postoperatively to assess changes in visual acuity, endothelial cell density (ECD), manifest refraction, and objective scatter index (OSI); they also assessed higher-order aberrations (HOAs) in eyes with 4- and 6-mm pupils preoperatively and for 3 months postoperatively. The preoperative mean manifest refraction spherical equivalent was -9.32 ±4.02 D (range, 6.75 to -16.50 D).

According to the investigators, there were no statistically significant differences postoperatively in distance UCVA P =.81), distance BCVA (P =.24), manifest refraction spherical equivalent (P =.18), and ECD (P =.76 between the groups. At 3 months postoperatively, the efficacy indices for the conventional and hole ICL groups were 1.01 and 1.03, respectively. No difference in OSI P =.32) or HOAs was found, but there was a statistically significant improvement from preoperative to 3-month postoperative logMAR distance BCVA for both groups (conventional ICL, P =.0005; hole ICL, P<.0001).

DISCUSSION

The peer-reviewed literature has consistently demonstrated that phakic IOL implantation is safe and effective for the correction of myopia and astigmatism.^4-8 Barsam and Allan examined three prospective, randomized, controlled trials comparing phakic IOL implantation to excimer laser vision correction in 228 eyes of 132 consecutive patients (myopic range, -6.00 to -20.00 D).⁹ They reported that, although the percentage of eyes with a distance UCVA of 20/20 or better 12 months postoperatively was comparable for both cohorts, the phakic IOL group scored significantly better on safety, contrast sensitivity, and patient satisfaction metrics. Additionally, data recently presented by STAAR Surgical on the Visian Toric ICL to the US Food and Drug Administration (FDA) Ophthalmic Devices Panel set a new benchmark for efficacy in an FDA refractive surgery trial, with 47.2% of 194 eyes gaining at least 1 line of distance UCVA compared with preoperative distance BCVA and 76.8% of eyes gaining 1 or more lines of distance BCVA.¹⁰

Notwithstanding these data, there are barriers to phakic IOL adoption. A 2013 survey of members of the International Society of Refractive Surgery reported that 47% versus 38% of respondents would choose excimer laser vision correction versus phakic IOL implantation for a 30-year-old patient with -10.00 D of myopia.¹¹ Additionally, the requirement of a laser iridotomy or surgical peripheral iridectomy before Visian ICL implantation is notable for its effects on patient comfort and convenience and for its associated cost. Obviating this step with the hole ICL simplifies the implantation procedure and eliminates the risk of complications associated with an iridotomy.^12-18

The first hole ICL was implanted by Erik L. Mertens, MD, FEBOphth, in June 2011. Over the past 3 years, the literature has established this lens to be safe, efficacious, and predictable.^19,20 Questions remain, however, about the effects of the central artificial hole on IOP, ECD, vault, and various measures of optical quality, including contrast sensitivity, OSI, and HOAs.

Although conventional ICL implantation induces fewer HOAs than wavefront-guided LASIK,²¹ the same has not yet been demonstrated with the hole ICL. Additionally, because the ciliary sulcus is not precisely aligned with the visual axis, it unclear whether Visian ICL decentration could adversely affect visual acuity or contrast sensitivity with the hole versus the conventional ICL.

The three studies discussed herein report several important findings about implantation of the hole ICL. Implantation of this lens:

• produced minimal to no increase in IOP;
• was associated with a stable ECD in the early preoperative period;
• led to vaults comparable with those of the conventional ICL;
• caused no change in contrast sensitivity or OSI; and
• did not degrade visual acuity or contrast sensitivity with lens decentration of 300 or 600 μm.

Ultimately, for all of the optical metrics evaluated in these three studies, there were no significant differences between the hole and conventional ICLs. As an additional benefit, the rate of postoperative cataract formation with the hole ICL may be lower than in the conventional ICL due to the natural flow of aqueous across the face of the crystalline lens.^22-25 After 569 hole Visian ICL implants, Dr. Mertens has reported zero incidence of cataract, IOP elevation, or acute angle-closure to date (personal communication).

A limitation of the studies discussed herein is their small cohorts and limited follow-up time. Metrics such as ECD require longer observation to establish stability. Further studies are needed to show that these findings are durable.

Jason P. Brinton, MD, is a partner at Durrie Vision in Overland Park, Kansas, and an Assistant Professor of Clinical Ophthalmology at the University of Kansas. Dr. Brinton states that he has a financial interest in STAAR Surgical. He may be reached at tel: +1 617 669 7299; e-mail: jpbrinton@gmail.com.

1. Higueras-Esteban A, Ortiz-Gomariz A, Gutiérrez-Ortega R, et al. Intraocular pressure after implantation of the Visian Implantable Collamer Lens with Centraflow without iridotomy. Am J Ophthalmol. 2013;156(4):800-805.
2. Pérez-Vives C, Ferrer-Blasco T, Madrid-Costa D, et al. Visual quality comparison of conventional and Hole-Visian Implantable Collamer Lens at different degrees of decentering. Br J Ophthalmol. 2014;98:59-64.
3. Huseynova T, Ozaki S, Ishizuka T, et al. Comparative study of two types of Implantable Collamer Lenses; one with and one without a central artificial hole [published online ahead of print February 3, 2014]. Am J Ophthalmol. doi: 10.1016/j.ajo.2014.01.032.
4. El Danasoury MA, El Maghraby A, Gamali TO. Comparison of iris-fixed Artisan lens implantation with excimer laser in situ keratomileusis in correcting myopia between -9.00 and -19.50 diopters: a randomized study. Ophthalmology. 2002;109(5):955-964.
5. Malecaze FJ, Hulin H, Bierer P, et al. A randomized paired eye comparison of two techniques for treating moderately high myopia: LASIK and Artisan phakic lens. Ophthalmology. 2002;109(9):1622-1630.
6. Sanders DR, Vukich JA. Comparison of implantable contact lens and laser assisted in situ keratomileusis for moderate to high myopia. Cornea. 2003;22(4):324-331.
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8. Kamiya K, Shimizu K, Igarashi A, Komatsu M. Comparison of Collamer toric implantable [corrected] contact lens implantation and wavefront-guided laser in situ keratomileusis for high myopic astigmatism. J Cataract Refract Surg. 2008;34(10):1687-1693.
9. Barsam A, Allan BD. Excimer laser refractive surgery versus phakic intraocular lenses for the correction of moderate to high myopia. Cochrane Database Syst Rev. 2010;(5):CD007679.
10. Visian Toric Implantable Collamer Lens PMA Supplement P030016. FDA Ophthalmic Devices Advisory Panel.http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/MedicalDevices/MedicalDevicesAdvisoryCommittee/ OphthalmicDevicesPanel/UCM385479.pdf. Accessed May 10, 2014.
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16. Vera V, Naqi A, Belovay GW, et al. Dysphotopsia after temporal versus superior laser peripheral iridotomy: a prospective randomized paired eye trial. Am J Ophthalmol. 2014;157(5):929-935.e2.
17. Kraemer C, Gramer E. Posterior synechiae after Nd:YAG laser iridotomy. A clinical study [in German]. Ophthalmol Z Dtsch Ophthalmol Ges. 1998;95(9):625-632.
18. Kumar N, Feyi-Waboso A. Intractable secondary glaucoma from hyphema following YAG iridotomy. Can J Ophthalmol. 2005;40(1):85-86.
19. Shimizu K, Kamiya K, Igarashi A, Shiratani T. Early clinical outcomes of implantation of posterior chamber phakic intraocular lens with a central hole (Hole ICL) for moderate to high myopia. Br J Ophthalmol. 2012;96(3):409-412.
20. Alfonso JF, Lisa C, Fernández-Vega Cueto L, et al. Clinical outcomes after implantation of a posterior chamber collagen copolymer phakic intraocular lens with a central hole for myopic correction. J Cataract Refract Surg. 2013;39(6):915-921.
21. Kamiya K, Igarashi A, Shimizu K, et al. Visual performance after posterior chamber phakic intraocular lens implantation and wavefront-guided laser in situ keratomileusis for low to moderate myopia. Am J Ophthalmol. 2012;153(6):1178-1186.e1. doi:10.1016/j.ajo.2011.12.005.
22. Shiratani T, Shimizu K, Fujisawa K, et al. Crystalline lens changes in porcine eyes with implanted phakic IOL (ICL) with a central hole. Graefes Arch Clin Exp Ophthalmol. 2008;246(5):719-728.
23. Fujisawa K, Shimizu K, Uga S, et al. Changes in the crystalline lens resulting from insertion of a phakic IOL (ICL) into the porcine eye. Graefes Arch Clin Exp Ophthalmol. 2007;245(1):114-122.
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