Ординатура / Офтальмология / Английские материалы / Phakic Intraocular Lenses_Hardten, Lindstrom, Davis_2004

The Implantable Contact Lens (ICL) (STAAR Surgical AG, Nidau, Switzerland) is a flexible, posterior chamber phakic intraocular lens (IOL) for the correction of myopia and hyperopia.1-35 The lens is designed to rest in the ciliary sulcus and is vaulted to avoid contact with the natural crystalline lens. It is manufactured by STAAR Surgical AG and is made of a proprietary collagen polyhema copolymer.

The first implants of the STAAR ICL were performed in 1993. In May 1997, the ICL was granted the European Conformité Européenne (CE) mark of approval and became available in European Union countries and others that recognize the CE mark. In February 1997, STAAR Surgical was allowed an investigational device exemption (IDE) to begin United States clinical trials for premarket approval by the US Food and Drug Administration (FDA). While long-term safety continues to be monitored, it is clear that short-term success is directly related to surgical technique at the time of implantation. Preservation of the natural crystalline lens requires deliberate and meticulous techniques. The following description details the steps necessary to successfully insert and position the ICL.

PREOPERATIVE PLANNING

Patient Selection

The ICL offers a noncorneal option for refractive correction. Current versions of the ICL are available between -3.00 and -20.00 diopters (D) and +1.50 to +20.00 D. The US clinical trials of the spherical versions of the ICL were

limited to patients with less than 2.50 D of pre-existing astigmatism. A toric model, which will correct up to 6 D of astigmatism, is in clinical trials. The ICL’s extended range of correction offers a compelling alternative for patients outside the accepted range of laser in-situ keratomileusis (LASIK). Ultimately, its use in lower power corrections may become routine provided that the longterm safety profile remains acceptable.

Preoperative Examination

An accurate refraction and complete eye examination is necessary preoperatively. A standard manifest and cycloplegic refraction is the basis for the calculation of the power of the selected implant. Using a standard vertex distance conversion formula, software supplied by the manufacturer will compute the ICL power in D at the ciliary sulcus plane. The ICL is manufactured in 11.0-, 11.5-, 12.0-, 12.5-, and 13.0-mm lengths. Correct sizing of the ICL is necessary to achieve proper positioning and clearance over the natural crystalline lens. One of the inherent difficulties of proper ICL sizing is determining the true sulcus diameter. Because the sulcus cannot be directly visualized, the anatomic correlation between the limbus and sulcus is used. White-to-white measurement (W-to-W) is used to estimate the diameter of the ciliary sulcus and to determine the desired length of the ICL. For myopic patients, 0.5 mm is added to the W-to-W length and for hyperopic correction, the ICL length is the same as the W-to-W. The fit of the ICL is an important factor in the safety profile of the lens, and care should be exercised in obtaining the measurement of W-to-W. Automated devices, such as

122 Chapter 12

Orbscan II (Bausch & Lomb Surgical, Rochester, NY) or IOL Master (Carl Zeiss Meditec, Dublin, Calif), use edge detection technology and generally provide reliable measurements. Conditions such as arcus senilis and pterygium can interfere with automated measurements, and it is recommended that all W-to-W measurements be confirmed by calipers. Gauge-type devices are prone to errors of parallax and are not generally accurate enough to reliably size an ICL.

The anterior chamber depth (ACD) is measured from the corneal endothelium to the anterior surface of the crystalline lens. This can be done optically as with an Orbscan II or with A-scan ultrasound. Deep anterior chambers facilitate ICL insertion and positioning. The initial experience of any surgeon should be limited to patients with a minimum ACD of 2.80 mm as measured from the corneal endothelium. With experience, chamber depths as low as 2.60 mm can be treated. The anterior chamber angle should be grade II or greater with gonioscopy. No evidence of cataract should be present. A fundoscopic exam is indicated to look for pre-existing retinal tears or holes.

day for 1 day prior to surgery. Tropicamide 1% drops and neosynephrine 2.5% drops are administered every 10 minutes for three applications prior to surgery. The ICL insertion requires a minimum pupil size of 7.0 mm at the time of surgery.

Topical anesthetic without intracameral lidocaine provides adequate anesthesia. Topical bupivacaine 0.75% (Abbott Laboratories, Chicago, Ill) and lidocaine 2% drops (Abbott Laboratories, Chicago, Ill) applied just prior to surgery are sufficient for most patients. Use of intraocular lidocaine has been associated with partial loss of mydriasis and has proven unnecessary for patient comfort. Peribulbar anesthetic is an acceptable alternative and may be preferred in the early phase of a surgeon’s experience. It is worth pointing out that any number of pharmacological regimens will achieve the same result of a maximally dilated pupil and anesthesia.

IMPLANTABLE CONTACT

LENS PREPARATION

Peripheral Iridectomy

A peripheral iridectomy or iridotomy is required to prevent pupillary block. The timing of the iridectomy, either preoperatively or at the time of lens insertion, is a matter of debate among ICL users. By far the most common technique, and that which is recommended by the manufacturer, is to perform a neodymium:yttrium-alu- minum-garnet (Nd:YAG) iridotomy 7 to 14 days prior to surgery. Two iridotomies, 0.2 mm in size, are placed superiorly 90 degrees apart. Paired iridotomies insure that at least one remains patent in the event the footplate of the ICL should occlude the other. Following the laser iridotomies, the patient is instructed to use prednisolone acetate 1% drops four times per day for 7 days. Surgical iridectomies at the time of ICL implantation have met with mixed success. Some of the problems associated with surgical peripheral iridectomies (PIs) include pigment accumulation on the surface of the implant and increased early postoperative inflammation. Of even greater concern has been the association of surgical iridectomies with traumatic cataract and zonular disruption. If the surgeon elects to do peripheral iridectomies as a primary procedure at the time of ICL insertion, it must be understood that a patent opening is mandatory once the pupil has been constricted.

Preoperative Medications

As with modern cataract surgery, adequate pupil dilation and ocular anesthesia facilitate the ICL procedure. Patients are pretreated with diclofenac drops four times per day for 2 days prior and ofloxacin drops four times per

Loading of the Implantable

Contact Lens Into the Cartridge

Loading of the ICL into the injection cartridge is an important part of the operation and should be performed by the surgeon under the operating microscope. Predictable delivery of the lens into the anterior chamber depends in large part on the care with which the implant is loaded.

The injector cartridge is filled with balanced salt solution (BSS) and then partially filled with Ocucoat (Storz Ophthalmics, Clearwater, Fla). The combination of BSS and Ocucoat minimizes friction between the ICL and the walls of the cartridge (Figure 12-1). Once the cartridge has been prepared, it is set aside and the ICL is removed from the saline solution in which it is packaged. Prolonged airdrying of the ICL reduces lens flexibility and should be avoided. The lens is inspected under the microscope to identify the positioning marks on the leading right and trailing left footplate (Figure 12-2). This orientation indicates the correct side up for the implant. The ICL is manufactured with a predetermined vault to clear the natural lens, and proper anterior-posterior orientation is necessary. The lens is positioned in the loading chamber of the injector in a convex orientation with the edges of the ICL beneath the lip of the cartridge (Figure 12-3). There are two central axis markers along the long axis of the implant. These landmarks are used to adjust the lens in a straight line down the shaft of the cartridge.

Once the lens is positioned in the open loading area of the injector, it is carefully grasped with a long, fine vertical action forceps. The lens is secured along the long axis

Figure 12-1. BSS followed by Ocucoat is used to prefill the injector prior to loading the ICL.

Figure 12-3. The ICL should be convex in the base of the cartridge with both edges tucked below the lip.

Figure 12-2. The ICL is inspected to insure that the leading right and trailing left markers are visible on the footplates.

Figure 12-4A. A long smooth forceps is used to advance the ICL into the barrel of the cartridge. Back and forth movements while advancing the ICL minimize friction and aid proper orientation.

across the optic for 75% of its length with the forceps. Using a slight downward movement, the lens is advanced into the barrel of the cartridge (Figure 12-4A). By advancing and retracting the lens slightly in a series of back and forth movements, surface adherence with the walls of the injector is minimized and the implant maintains the desired orientation.

The plunger is inserted into the injector mechanism and the loaded cartridge is locked into position. A moistened foam-tipped plunger is used to advance the ICL down the barrel to the tip of the injector (Figure 12-4B). The clear barrel of the injector enables identification of the positioning markers. These should be visible at the 12:00 position and be in straight alignment down the shaft. The fully assembled injector is then placed tip down into a container of BSS to keep the contents hydrated. Any

air bubbles are evacuated from the loaded cartridge with Ocucoat. This is accomplished by inserting the viscoelastic cannula into the tip of the injector and backfilling the cartridge (Figure 12-5).

Folded Implantable

Contact Lens Geometry

The desired shape of the folded ICL is a uniform cylinder with equal distribution of the mass of the ICL on either side of the midpoint of the long axis (Figure 12-6). The cylinder formed by the loaded ICL should be free of any twisting, which would be evident as spiral folds. Significant torsion of the ICL within the cartridge results in an unwanted spiral motion during lens delivery. If this occurs, the surgeon must counter-rotate the cartridge to prevent delivery of the ICL in an inverted position.

Figure 12-4B. Once the ICL has been advanced into the barrel of the injector, a hydrated foam tip plunger is used to advance the lens.

Figure 12-5. Ocucoat is used to backfill the injector to remove trapped air bubbles.

Figure 12-6. The properly loaded ICL is free of spiral folds.

ICL Injector

Two styles of injectors are available: a screw type and a plunger type. The screw type offers a more controlled injection but requires a two-handed technique. The surgeon holds the body of the injector in his or her dominant hand and turns the advancing screw with the other hand. The plunger style injector can be operated with only the dominant hand and the other hand can be used to stabilize the globe. Either type is acceptable, and the choice is a matter of personal preference.

The foam-tipped plunger used to advance the ICL within the injector cartridge is supplied in a dry compressed state. The tip must be immersed into BSS to expand the sponge prior to insertion. Failure to do so results in over ride of the plunger tip onto the implant. The subsequent expansion of the tip may entrap the implant and interfere with release of the ICL into the eye. Soaking of the plunger tip for 30 seconds in BSS prior to advancing the ICL eliminates this potential difficulty.

OPERATIVE TECHNIQUE

The operative technique contains many elements familiar to cataract surgeons. None of the individual steps are difficult for an experienced surgeon, but all require precise execution.

Anesthesia

A sterile field is obtained using a standard prep and drape appropriate for intraocular surgery. ICL surgery should be performed in a fully equipped surgery suite under controlled conditions with monitored intravenous anesthesia. Anesthesia consists of topical 0.5% tetracaine and 0.75% bupivacaine drops administered just prior to surgery. Intravenous access is established and sedation is titrated to patient comfort. Minimal use of intravenous Versed (Roche Pharmaceuticals, Nutley, NJ) has proven effective for most patients, taking care to avoid oversedation. The intended level of sedation results in a conscious and cooperative patient. Light induced sleep with the attending risk of uncontrolled awakening during the operation should be avoided.

Surgical Approach

The ICL is well-suited to a temporal clear cornea approach. Unlike cataract surgery, the angle of entry into the anterior chamber must remain parallel to the plane of the iris. A temporal approach provides ideal exposure for a level working plane. Superior incisions, working over the brow, tend to favor a more posteriorly angled entry. This hinders instrument movement within the anterior chamber and increases the risk of unintended contact with the anterior lens capsule.

Figure 12-9. A self-sealing 3 mm by 2 mm clear cornea incision is made from a temporal approach.

nula is carefully positioned through the paracentesis, making sure the tip clears Descemet’s membrane but does not extend over the crystalline lens (Figure 12-8). In cataract surgery it is common practice to cross the anterior chamber and inject viscoelastic as the cannula is withdrawn. In ICL surgery the cannula tip should not extend more than 1 mm beyond the wound; to do so risks unintentional touch of the anterior lens capsule. Ocucoat is injected until the iris-lens diaphragm shifts backward slightly and the eye is moderately firm. The tip of the cannula must clear the inside lip of the corneal wound but not extend unnecessarily into the anterior chamber. It is worth keeping in mind that failure to insert the cannula tip far enough into the anterior chamber and injection of viscoelastic within the paracentesis track risks viscodissection of Descemet’s membrane and endothelial detachment.

Paracentesis

A clean and sharp diamond knife facilitates a controlled entry into the anterior chamber. Paired 1.0-mm paracentesis incisions are placed at the 6:00 and 12:00 positions (Figure 12-7). Care must be taken to enter the chamber in a slow, controlled manner. A dull or debris-laden blade can lead to corneal compression prior to anterior chamber penetration. Entry of the chamber any further than is necessary to just clear the shoulder of the blade risks inadvertent touch or laceration of the anterior capsule.

Injection of Viscoelastic

Once both paracentesis ports have been made, viscoelastic is injected into the anterior chamber. Ocucoat or another low molecular weight, noncohesive viscoelastic is preferred due to the minimal resistance it offers to unfolding of the implant in the anterior chamber. Higher molecular weight agents can cause prolonged unfolding time or interfere with positioning of the ICL. The injection can-

Corneal Incision

The incision is made at the temporal clear cornea using the same architecture as for cataract surgery (Figure 12-9). A cord length of 3.0 to 3.2 mm with a 2.0-mm tunnel provides adequate room for the lens injector and a secure selfsealing closure. A sharp diamond knife allows controlled entry into the anterior chamber. Additional Ocucoat may be injected following completion of the wound to maintain a deep anterior chamber.

Insertion of the ICL

The preloaded injector mechanism is brought into the operative field, and the tip of the cartridge is inserted into the clear cornea wound (Figure 12-10A). The surgical plane is parallel to the iris, avoiding contact with the corneal endothelium and anterior lens capsule. A slow advance-and-pause tapping motion is used to direct the ICL into the anterior chamber. No attempt should be made to direct the leading footplates of the ICL under the iris. A positioning mark is located on the leading right and

Figure 12-10A. The injector cartridge is placed just inside the wound.

Figure 12-11. Once the ICL is inside the anterior chamber, Ocucoat is used to refill the chamber and push the implant posterior.

trailing left footplate. When one-half to three-quarters of the ICL is out of the injector cartridge, a slow unfolding of the implant will start (Figure 12-10B). The upward unfolding of the ICL should be symmetric along the long axis of the implant. The care used preoperatively to load the ICL will be evident in a controlled delivery. To insure proper anterior-posterior orientation of the ICL within the anterior chamber, any spiraling of the implant as it leaves the cartridge must be neutralized by counter-rotation of the injector by the surgeon. Once the ICL is situated in the anterior chamber, additional Ocucoat is injected to deepen the chamber and direct the implant posteriorly (Figure 12-11). If the ICL should enter the eye upside-down, no attempt should be made to reposition it inside the eye. The implant should instead be removed and reinserted. Removal of the ICL is accomplished through the same incision using two smooth forceps with a hand-over-hand technique. The implant is pliable enough to allow easy removal through the same incision (Figure 12-12).

Figure 12-10B. The ICL is slowly injected into the anterior chamber using an advance-and-pause tapping motion. If the lens starts to twist, the cartridge can be rotated to insure right side up orientation.

Figure 12-12. The ICL can be easily removed through a 3-mm incision by grasping the edge of the implant with a smooth forceps and using a hand-over-hand technique to withdraw the lens.

Positioning of the Implantable Contact Lens

Once in the eye, the ICL must be repositioned posterior to the iris plane. The paracentesis incisions are used to provide access to the ICL. This avoids gaping of the primary wound and loss of chamber depth. The leading or nasal footplates are positioned first. If any difficulty with pupil size or positioning should occur, this will leave the footplates closest to the wound available for removal of the ICL. When working inside the eye, the central 6 mm of the crystalline lens is considered the “no touch zone.” All instruments within the anterior chamber should be kept to the peripheral area outside of the central 6 mm. Several instruments have been designed to position the ICL posterior to the iris; all utilize surface contact with the ICL and light posterior pressure to direct the footplates. The Vukich ICL Manipulator (American Surgical Instruments Corporation, Westmont, Ill, AE-2531) has a paddle-shaped

Figure 12-13. The ICL manipulator is inserted through the side port incision. Using gentile posterior pressure, the footplates are tucked one at a time under the iris. Care should be taken to avoid crossing the central optical zone and to avoid touching the crystalline lens.

Figure 12-14A. External view of a toric ICL 1 year following implantation.

hand is the key to avoiding complications. It is important to make certain that the toric ICL is implanted in the correct orientation (Figure 12-14).

Figure 12-14B. The diamond shaped axial indicator mark on the toric ICL is best visualized in red reflex.

tip with a lightly textured surface to increase frictional grip with the implant. Other instruments, including the Deitz Tucker (Duckworth and Kent, Hertforshire, England, 6- 479) and Pallikaris Olive Tip Positioner (Duckworth and Kent, 6-481), have been developed for the same purpose. With the ICL manipulator in contact with the footplate, the proper motion is gentle posterior pressure combined with slight rotation of one clock hour or less. This maneuver is repeated over each corner of the implant until all four footplates are posterior to the iris plane (Figure 12-13). The myopic ICL should not be rotated once placed behind the iris. Adjustment of the implant, if necessary, is accomplished by a gentle nudge at the junction of the footplate and optic. The delicate touch used for all of the intraocular portions of the surgery has lead to the term “butterfly surgery.” This concept of deliberate movement and a soft

Removal of Viscoelastic

Once the footplates are visually confirmed to be posterior to the iris, the pupil is pharmacologically constricted with Miochol (Novartis, Cambridge, Mass). Irrigating the anterior chamber with BSS on a 27-gauge cannula through the wound is generally sufficient to flush the Ocucoat from the eye. Automated irrigation-aspiration has not proven necessary and risks dislocation of the ICL.

Postoperative Medications

The wound is tested to confirm a self-sealing closure, and topical dexamethasone (4mg/mL) and cefazolin (100 mg/ 0.5 cc) are applied. The patient is sent home on ofloxacin four times a day for 1 week and tobramycin/dexamethasone four times a day tapering over a 2-week schedule.

Postoperative Care

The patient is rechecked in the office between 2 to 4 hours following surgery. Observations include centration of the implant and measurement of intraocular pressure (IOP). Incomplete iridectomies or retained viscoelastic can cause IOP elevation. IOPs greater than 20 mmHg should be treated medically. Topical aproclonidine 1% drops and pilocarpine 1% is usually sufficient to lower the IOP. Rarely, the paracentesis must be burped at the slit lamp or an inadequate peripheral iridectomy enlarged with the Nd:YAG laser to control IOP.

Efficacy of the Implantable Contact Lens

Three-year experience from the US Phase III clinical trial provides the best available analysis of the intermediate term safety and efficacy of the ICL. Fifteen centers participated in the evaluation of the Version 4 ICL for myopia. A total of 526 eyes were analyzed at 3 years. The

Figure 12-15. At 3 years postoperatively, 95% of eyes treated with the ICL achieved 20/40 or better uncorrected acuity.

Figure 12-16A. At 3 years postoperatively, 88% of eyes treated with the ICL were within 1.00 D of the attempted correction.

Figure 12-16B. A scatter plot of the attempted vs achieved result demonstrates full correction of myopia up to -17.00 D with anticipated undercorrection between -17 and -20.00 D.

mean preoperative spherical equivalent was -10.05 D, ranging from -3.00 to -20.00 D. All patients had less than 2.5 D of pre-existing astigmatism.

EFFECTIVENESS OUTCOMES

Key efficacy outcomes are stratified into three groups by preoperative manifest refractive spherical equivalent (MRSE). Results of the myopic ICL clinical investigation provide definitive substantiation of the overall effectiveness of the ICL to correct moderate to high myopic refractive errors.

ALL EYES

For the subset of eyes with preoperative best spectaclecorrected visual acuity (BSCVA) 20/20 or better and tar-

geted for emmetropia ( 0.5 D), the proportion of eyes with 20/40 or better uncorrected visual acuity (UCVA) at 24 and 36 months, respectively, was 93.4% and 94.7% (Figure 12-15). The proportion of eyes with UCVA 20/20 or better was 59.6% at 24 months and 59.3% at 36 months postoperatively. For the overall myopic ICL PMA Cohort, MRSE within 1.0 D was achieved in 90.1% of eyes at 24 months and in 88.2% of eyes at 36 months, as compared to the FDA target of 75% (Figure 12-16). Predictability of the MRSE within 0.50 D was 66.1% at 24 months and 67.5% at 36 months after ICL surgery, comparing favorably with the FDA target of 50%.

PATIENT SATISFACTION

Subjectively, at 24 months, 94.3% of patients were very/extremely satisfied, with only one patient unsatisfied (0.2%) (Figure 12-17). Similarly, 92.1% were very/extremely satisfied at 36 months (0.6% unsatisfied).

Stratified by Preoperative Mean Refractive Spherical Equivalent

For the subset of eyes with preoperative BSCVA of 20/20 or better and targeting emmetropia at 3 years, 98.3% of eyes in the <7 D group, 92.8% of eyes in the >7 to 10 D group, and 93.8% of eyes in the >10 D group had UCVA of 20/40 or better. UCVA 20/20 or better was achieved by 72.4% of eyes in the <7 D group, by 62.7% of eyes in the >7 to 10 D group, and by 37.5% of eyes in the >10 D group. At 36 months, attempted vs achieved MRSE outcomes were within 1.0 D in 97.2% of the <7 D group, 93.1% of the >7 to 10 D group, and 80% of the >10 D group compared to the overall FDA target of 75% and >7 D target of 60%.

Figure 12-17. A high level of patient satisfaction with the ICL was reported at all visits.

Predictability of the refractive outcome also exceeded the FDA target values for all three dioptric groups. For the myopic ICL cohort, 84.7% of the <7 D group, 71.0% of the >7 D to 10 D group, and 56.9% of the >10 D group were within 0.50 D of the target refraction at 36 months compared to the FDA targets of 50% for all eyes and 30% for eyes with >7 D of refractive error.

Stratified by Preoperative Mean Refractive Spherical Equivalent

Subjective patient satisfaction was rated as very/extremely satisfied in 95.8% of cases in the <7 D group, 94.3% in the >7 D to 10 D group, and 88.4% in the high myopia group (>10 D). None of the patients in both the low and middle myopic groups reported being unsatisfied. Only two cases (1.4%) reported being unsatisfied in the high myopia group (>10 D).

Achieved vs intended correction is summarized in Figure 12-16. At 3 years postoperatively, 88% of patients were within 1.00 D and 98% within 2.00 D of intended correction. Overall UCVA at the patient’s last visit was 20/40 or better in 95% and 20/25 or better in 74% of eyes. One or more lines of improved best specta- cle-corrected acuity were observed in 38% and two or more lines in 6.5% of patients. Uncorrected postoperative acuity was equal to or exceeded preoperative best spectacle correction in 57% of patients.

LENS OPACITY ANALYSIS

Induced crystalline lens opacity as a result of surgical trauma at the time of implantation, microtrauma from the ICL, and potential metabolic changes have been carefully analyzed. Much has been learned from the early experience with the ICL.34 Sizing, fit, and geometry are important variables in the safety profile of the lens. The initial

versions of the ICL document the evolution of our understanding of how a phakic IOL can safely occupy the potential space anterior to the natural crystalline lens. The prototype version 3 (V3) ICL lens design was responsible for many of the lens opacities reported in the early experience with the ICL before being replaced by version 4 (V4).23 The basic difference between the V3 and V4 ICL is in the vaulting characteristics. The V4 lens has an additional 0.5 to 0.6 mm of anterior vault depending upon dioptric power and haptic length. This additional clearance has proven to have a beneficial effect. Lens opacities that appear early (<90 days postoperatively) following implantation of an ICL are more frequently than not asymptomatic and most likely due to surgically induced trauma. There is a strong association between anterior subcapsular opacities and removal and reinsertion of the ICL on the day of surgery, which suggests surgical trauma as a factor in their development. Early anterior subcapsular opacities tend to be focal and nonprogressive and occur in approximately 2% of patients, but result in clinically significant cataracts in less than 1% of cases. The development of nonvisually significant traumatic lens opacities appears to be related to surgeon experience. Of the early lens opacities observed in the US clinical trials, all but one were among the first seven ICLs implanted by any surgeon, suggesting a learning curve for the use of the lens.

ICL removal and reinsertion during surgery or on the same day of surgery as a result of the ICL being implanted upside-down has been reported in up to 2% of patients. The subsequent additional manipulation has been associated with a higher rate of anterior subcapsular lens opacity. In the US clinical trial, of the six eyes developing anterior subcapsular opacities after removal and reinsertion, four (67%) of the opacities were seen within the first postoperative week and all were first seen within 3 months of surgery. This highly suggests surgical trauma as the most likely etiology of the lens opacities.

The time course of first appearance of observed anterior subcapsular opacities shows that the majority of changes occur in the first 12 months. Half of them were first seen by the first postoperative week, 79% by 6 months, 93% by 1 year, and 100% by 2 years postoperatively.

QUALITY OF VISION WITH THE

IMPLANTABLE CONTACT LENS

Patients subjectively rate the quality of visual acuity with the ICL very highly. Objective comparison of visual quality by measuring postoperative wavefront aberrations allows us to compare the image quality due to higherorder aberrations. In one published study, a comparison of the measured coma and spherical aberration in postoperative LASIK and ICL eyes demonstrated significantly less of these higher-order aberrations.22 While the magnitude of