Phakic Intraocular Lenses ("Implantable contact lenses")

A phakic intraocular lens (IOL) is a lens implant that is placed inside the eye without removing the eye’s natural lens - hence the term phakic, which refers to the presence of the natural lens.  There are presently two phakic IOLs that have been FDA approved: the Verisyse phakic IOL and the Visian ICL™, the latter were approved in 2005.

The Verisyse phakic IOL is the first U.S. FDA approved phakic IOL.  This IOL provides a new option for those who are moderately to very myopic (nearsighted), that is, between –5.0 and –20.0 diopters.  As you are about to see, the results with this lens are extraordinary, as is the safety profile.  Let’s take a deeper look.

 A Close-Up View of the Verisyse Phakic IOL

The Verisyse IOL and other phakic IOLs have sometimes been referred to as “implantable contact lenses.  I like the term only insofar as this may help one to think of it as replacing a contact lens, which, in fact, it can and does.  Unlike traditional IOLs, however, phakic IOLs are placed inside the eye without removing the natural lens of the eye.  The Verisyse IOL is placed behind the cornea, attached to the iris, and rests in front of the eye’s natural lens.  In contrast, when the clear natural lens of the eye is removed and an IOL is implanted to replace it, this is known as “refractive lens exchange”.  This latter topic will be reviewed in the next chapter (Chapter Thirteen).  When a clouded lens in the eye (a cataract) is removed and it is replaced with an IOL, this is known as – you guessed it – cataract surgery!

IOLs have been placed inside the eye in conjunction with cataract extraction since the 1960’s.  In fact, tens of millions of these procedures in the U.S. alone have demonstrated their ability to correct vision safely, effectively, and with a fairly high degree of accuracy.  The phakic IOL was introduced in the 1980’s and has a shorter period of follow-up with far fewer procedures having been completed - as compared to cataract extraction with IOLs.  

The Verisyse IOL was first introduced in Europe more than 17 years ago under the name Artisan phakic IOL.  Only after AMO (Advanced Medical Optics, Irvine, California) acquired distribution rights to the lens was it renamed the Verisyse IOL.  Over 150,000 of these lenses have been safely implanted worldwide[i]. 

The U.S. FDA granted approval for implantation of the Verisyse IOL on September 10, 2004.  This IOL can only be implanted by highly-trained ophthalmologists (EyeMD’s) that also have specific training on the use of this lens (true for every procedure mentioned in this website). 

Are You a Candidate for the Verisyse phakic IOL?

If you are 21 years of age or older and you are very nearsighted, you might be a candidate for the Verisyse IOL.  If you know your glasses or contact lens prescription, this will be very helpful in determining your initial candidacy.  Here are the basic inclusion criteria:

· You must be 21 years of age

· Your eyes must be healthy, without any disorders such as cataract, glaucoma, history of retinal detachment, etc.

· Your eyes must not have any anomalies of the iris or pupil, such as an abnormally shaped pupil

· Your corneas should be healthy, without scarring or dystrophy

· Your nearsightedness should be correctable with lenses between –5.0 and –20.0 diopters

· If you have astigmatism, it should be no more than 2.5 diopters *see my comments below

· Your myopia should be stable, with no more than 0.5 diopters of change in the six months prior to surgery

· You must nor currently be pregnant or nursing

· Your eye’s anterior chamber depth must be at least 3.2 mm (this prevents the IOL from coming into contact with the endothelium of the cornea)

· You must have a “healthy” endothelia cell density in your cornea (this number varies by age and your surgeon will make this determination in a pre-op visit)

· There is not another vision correction procedure that provides a better alternative for your visual condition

How Does the Verisyse IOL Work?

Implanting the Verisyse IOL involves placing the lens implant behind your cornea and on top of your iris.  Then lens is actually attached to the iris with two “iridoplastic bridges”, the latter of which pinch a small amount of iris tissue to hold the lens in position. This aspect of the procedure is called enclavation.  The lens implant will rest in front of the pupil and in front of your natural lens.  The incision through which the lens is implanted may be closed with one or more small stitches.

When the Verisyse™ IOL power is properly chosen based on all the measurements of your eye, light will come to a sharper focal point on your retina, which results in clearer vision.  If there is significant astigmatism, this must also be addressed if one is to have the best possible uncorrected vision.  In the FDA trials, patients with more than 2.5 diopters of astigmatism were excluded.  However, in many cases, even greater degrees of astigmatism might be managed (diminished) using proper placement of the incision along with limbal relaxing incisions, the latter of which entail placing incisions along the limbus (where cornea meets sclera) to flatten the steeper meridian of the cornea (see Chapter Fifteen).  

How the Verisyse IOL Looks Inside Your Eye

It is worth repeating that the Verisyse IOL works in conjunction with one’s natural lens, because the natural lens is what allows one to focus between near and far.  For those who are in their late 40’s and beyond, some or all of this focusing power is lost due to presbyopia; however, this is still an important point to understand.  If you need reading glasses, bifocals, or “bifocal contacts”, you will most likely need reading glasses after implantation with this lens.  In some patients, those who didn’t need reading glasses before the surgery will need them afterwards.

Because the Verisyse IOL is fixed in position (to the iris), it is unable to move inside the eye.  It cannot normally be dislodged, dislocated, lost, etc.  Also, the lens results in no unusual sensation and its presence cannot be perceived (except by improved vision), unlike a contact lens.

Efficacy Analysis – Visual Acuity Outcomes

In the FDA trials, the mean age (consider this the average age if you are not statistically inclined) of patients who entered the studies and underwent implantation with the Verisyse™ IOL was 39.6 years.  The majority of patients were between the ages of 21 and 50 years.  The mean lens power implanted was –12.6 diopters with the range being between –5.0 and –20.0 diopters.

When emmetropia (no distance correction required) was the goal, at one year post-op, 47.1% were 20/20 or better, 93.6% were 20/40 or better, and 100% were 20/80 or better.  At the three year post-op visit, 44.3% were 20/20 or better, 92% were 20/40 or better, and 97.7% were 20/80 or better[ii].  This is really very good vision when you realize that, on average, these patients had a pre-operative far point (the farthest point in front of the eye that can be seen clearly) of only 3.2 inches!  If you happen to be one of these patients, you know that you almost need a pair of glasses on to find your contacts, if you wear them.  Or for that matter, as a lot of these patients say, “I need my glasses on to find my glasses”! 

As a contributory anecdote, my wife, who underwent LASIK in 2002, wore her glasses while asleep at night prior to her surgery.  She had myopia of about –9.0 diopters in one eye and –10.5 diopters in the other eye and she can attest to the fact that she felt “nervous” going to bed without her glasses! Now, this obviously would seem quite uncomfortable and I’m sure it was, but she knew she couldn’t see well enough to find her glasses quickly in case of an emergency in the night.  For those who are not –9.0 diopters of myopia and above and have trouble empathizing, I think this helps to illustrate the degree of visual disability that these individuals have. 

Back to the studies… For those patients who had best corrected visual acuity (BCVA) of 20/20 or better pre-operatively (realize, especially at this level of myopia, many of these patients cannot read the 20/20 line, even with correction), the number that had 20/20 or better BCVA post-operatively was 95.1% and 95.3% at one and three years, respectively.  All of these patients had 20/40 or better BCVA at every time interval (6 months, one year, two years, and three years) during the course of the study. 

From a patient satisfaction survey, 73.6% reported no change in glare at night from pre- to post-operatively.  In the same regard, 72% reported no change in halos and 78.5% reported no change in starburst, from pre-op to post-op. 

A contrast sensitivity sub-study concluded that there was no decrease in contrast sensitivity under mesopic (dim light) and photopic (bright light) conditions for patients implanted with the Verisyse ™ IOL.  This is exciting and powerful evidence, as even LASIK generally appears to cause a reduction in contrast sensitivity (see Chapter Seven).  

Risks and Complications

In the FDA trials, 4.5% of eyes implanted with the Verisyse™ IOL developed lens opacities (the equivalent of cataract), however, the majority of these opacities were not visually significant.  Only four of the opacities (out of 1088 eyes implanted) were significant and three of those four underwent cataract extraction.  However, even these lens opacities may not have been directly attributable to the Verisyse™ IOL insertion as it is well known that the rate of cataract surgery in the general population for individuals greater than 40 years of age is 1.7% to 10.8%.

Cataract surgeries along with IOL insertion procedures are known to result in some loss of endothelial cells in the cornea.  The endothelial cells, located on the posterior (back) side of the cornea, pump fluid out of the cornea keeping it relatively dehydrated and, therefore, clear.  In the FDA trials involving the Verisyse™ IOL, corneal endothelial cell densities were recorded pre- and post-operatively and followed carefully.  It was found that, on average, only 0.4% of the endothelial cells were lost from pre-op to the six month post-op visit.  This is noteworthy, as the report goes on to say, because cataract removal and IOL implantation surgery generally results in an average endothelial cell loss of 10% due to ocular trauma.  Over the first three years, however, the rate of endothelial cell density loss was found to be 1.8%[iii].  In contrast, the normal rate of endothelial cell density loss during adult life is about 0.6% per year[iv].  Is this an issue?  Is it threatening? 

The FDA stated the following with regard to the corneal endothelial cell density loss:  “The 3-year data from the clinical study indicates a continual steady loss of endothelial cells of –1.8% per year and this rate has not been established as safe.  If endothelial cell loss continues at the rate of 1.8% per year, 39% of patients are expected to lose 50% of their corneal endothelial cells within 25 years of implantation.  The long-term effect on the cornea’s health of a 50% loss in corneal endothelial cells is unknown.  However, if too many cells are lost the patient may need a corneal transplant.  Therefore, it is very important that the patient’s endothelial cell density is periodically monitored.”

Patients who are very nearsighted are at higher risk of developing glaucoma.  Glaucoma is a disease characterized by optic nerve damage with consequent peripheral vision loss that is associated with the pressure inside the eye.  The effect of implantation of the Verisyse™ IOL inside the eye on the development of glaucoma is unknown, as the anterior chamber angle (where the aqueous humor inside the eye egresses) was not analyzed in this study.  However, only about 1% of the subjects in this study developed increased eye pressure that required glaucoma medication long term.  I would submit to you that this small number of individuals affected by increased intraocular pressure may have occurred with or without the surgery.  As previously noted, those who are very nearsighted are already at increased risk of glaucoma.

According to Ophtec’s Patient Information Brochure, “complications associated with the implantation procedure and/or the lens itself are rare[v].  During the clinical trial for this product, the following types of events were reported:

– 1.36% of patients had their IOL exchanged (due to inadequate surgical fixation, the lens optic size was smaller than their pupil size, or a power calculation error).

– 1.51% of patients had their IOL removed (due to inflammatory response, patient anxiety, the lens optic was smaller than their pupil size, postoperative trauma, or surgical trauma).

– 0.60% of patients had to have their IOL reattached (due to inadequate surgical fixation or postoperative trauma).

– 0.45% of patients required repair of their retina

– 0.15% of patients experienced surgical trauma which required retinal repair.”

Clinical Investigators Comment on the Verisyse™ IOL

Ophthalmology Management had discussions with two of the original clinical investigators for theVerisye™ IOL to determine their reactions to the lens as well as their patients reactions to it, one year after FDA approval of the lens[vi].

Gregory J. Pamel, M.D., attending surgeon and ophthalmologist at Manhattan Eye, Ear and Throat Hospital in New York, and investigator for the Verisyse™, stated that his patients’ reactions to the IOL had been “overwhelmingly positive.”

“During the clinical trials, the FDA mandated that we wait 3 months before implanting the second eye — everyone wanted to have their second eye done right away, “ he said.  “Patients who were essentially functionally blind without glasses or contacts can now function with the lens, so the results are quite dramatic.” 

Eric D. Donnenfeld, M.D., medical director of TLC Laser Center in New York, also functioned as one of the investigators of the Verisyse™IOL during the FDA trials.  Dr. Donnenfeld commented that his patients who were not candidates for LASIK were excited about the availability of the lens implant.  He felt the results spoke for themselves and were quite impressive.

“The patients who are candidates for this lens are the most visually handicapped in our practice, so they are also the most delighted with the results,” he said.  “We’re taking these patients from –12.0 D, -18 D, and –20 D (diopters) and giving them good uncorrected visual acuity, so they are thrilled.”

Dr. Pamel went on to state that the calculations for determining the lens implant power were quite accurate and, as such, he commented that patient expectations were exceeded in terms of the quality of their vision.  “Over 50% of the time, patients have gained one or more lines of vision” over their best corrected visual acuity (BCVA) prior to surgery.  

Verisyse™ Phakic IOL Versus LASIK

If you’ve read Chapter Seven on LASIK, you might recall that a substantial number of patients are not candidates for traditional LASIK either because their corneas are too thin or because they are too nearsighted.  Most refractive surgeons will not use LASIK when a patient has myopia greater than approximately –9.0 or –10.0 diopters because of greater incidence and severity of visual aberrations in this sub-group, including such visual phenomena as halos and starburst at night, glare, and reduced contrast sensitivity.  This is where the Verisyse™ IOL (or another phakic IOL) comes in – there are no contraindications for this lens when it comes to corneal thickness and the lens really shines for those who are extremely myopic, theoretically working just as well in those who are –5.0 D as it would in those who are –20.0 diopters myopic. 

The Verisyse™ IOL is also appealing because, unlike any form of LASIK, the procedure is, for the most part, readily reversible.  To be sure, the product literature informs individuals that vision may not return to pre-operative levels if the lens is removed, however, I believe this is stated primarily because making an incision to implant the lens may alter the corneal curvature, creating or altering astigmatism.  Also, as you’ve read, cataract development has occurred following implantation with the lens, but it is very rare.

If you are risk averse, and you fear complications of LASIK (albeit rare), with potentially permanent changes to your cornea, and you are –5.0 or more diopters myopic, then I am speaking to you!  If you’ve read Chapter Seven on LASIK, then you realize that glare and halos are possible, if unlikely, but a reduction in contrast sensitivity is likely.  As previously stated, loss of contrast sensitivity did not occur in the FDA trials with implantation of the Verisyse™ IOL.  Let’s look at a patient example.

Case Study Presented by Gregory J. Pamel, M.D.

Dr. Pamel presented the following case to Cataract and refractive surgery Today[vii] in April, 2005.

“A 47-year old female underwent standard LASIK with the Ladarvision system in her left eye in 2001.  She had decided on uniocular surgery, because she was very concerned about not having a good outcome and did not want to risk both eyes at the same time.  Postoperatively, she remained undercorrected in that eye and wore a soft contact lens for her residual refractive error.  However, she still complained of glares and halos at night as well as ghosting of images with that eye.  Due to her dissatisfaction with her primary LASIK treatment (and her reluctance to undergo an enhancement), she decided to research alternatives for her second eye.  She presented to me in November 2004 for a Verisyse consultation with a very long list of questions (a sign that she might not be a candidate for any refractive procedure).”

“Upon examination, the uncorrected visual acuity (UCVA) in her LASIK-treated eye was 20/60, which corrected to 20/20 with a manifest refraction of –1.50D of sphere {she remained slightly nearsighted}.  In her untreated eye, her best-corrected visual acuity (BCVA) was 20/20 with a manifest refraction of –9.25 +0.75 x 100˚.  After detailed informed consent, she received a Verisyse (6 mm optic) phakic lens implant (-10.0 D) in that eye.  At the 1-month postoperative period, her UCVA measured 20/20 (with a plano –0.25 x 169˚ refraction.  Subjectively, she had no glare, halos, or ghosting with the Verisyse eye, and she was extremely pleased with her outcome.”

Dr. Pamel goes on in his analysis of this case study to present the patient’s wavefront error in each eye, as a matter of further comparison between LASIK and the Verisyse™ IOL.  Wavefront error is a scientific way of capturing the reflected rays of light from an eye to determine both the eye’s refractive error (lower order aberrations) as well as higher order aberrations.  In her case, the LASIK treated eye was shown to have 0.133mm (microns, i.e., one micron equals 1/1000th of a millimeter) of wavefront error and the wavefront error in the Verisyse™ implanted eye was only 0.073mm.  Prior to the Verisyse™ IOL implantation, the wavefront error in the non-LASIK eye was 0.073mm. 

“These results parallel the contrast sensitivity results in the FDA clinical trial, which showed no significant difference in contrast sensitivity tested under mesopic (dim light) conditions with glare between preoperative and postoperative levels”, said Dr. Pamel. 

Quality of Vision:  LASIK VS. Verisyse™ IOL

In general, the higher the level of correction on the corneal plane, as in the case of LASIK, the greater the chance of glare, halos, and decreased contrast sensitivity, resulting in disappointing vision[viii].  Ophthalmologist and world-renowned optics expert, Jack T. Holladay, M.D., has shown that this complication of corneal refractive surgery (such as LASIK) is secondary to an alteration of the natural prolate shape of the cornea (steeper in the center, flatter in the periphery) to an oblate shape, which is flatter in the center and steeper in the periphery[ix].  For a more thorough review of this concept, please refer to Chapter Seven.

A recent study involving patients implanted with the Verisyse™ IOL examined the effect of this lens on contrast sensitivity[x].  In this study, 49 eyes of 30 patients were examined who, on average, had preoperative myopia of –12.16 diopters.  After implantation with the IOL, 90% were within 1.0 diopter of the intended post-op refractive result, and 39% gained one or more lines of visual acuity on the Snellen eye chart.  When compared with preoperative measurements, postoperative contrast sensitivity was increased under photopic (bright light) conditions and slightly decreased under mesopic (dim light) conditions.  The group concluded with the following: “Increases in photopic contrast sensitivity values after implantation of this phakic intraocular lens stand in distinction to the decreases in photopic contrast sensitivity previously reported after LASIK correction of this degree of myopia.”  

One group of international investigators completed an excellent, prospective, randomized clinical trial in which they compared the Verisyse™ IOL to LASIK in a group of patients with myopia between –9.0 and –19.50 diopters (average –13.50 diopters)[xi].  In this study, 45 eyes received the Verisyse™ IOL and 45 eyes received LASIK.  An additional 18 patients received a Verisyse™ lens in one eye and LASIK in the opposite eye. 

The uncorrected visual acuity (UCVA) was 20/20 or better in 20.9% of the Verisyse™ eyes compared to only 12.2% of the LASIK eyes.  The UCVA was 20/40 or better in 88.4% of the Verisyse™ eyes compared to only 58.5% of the LASIK eyes.  Not a single Verisyse™ eye lost two lines of best spectacle corrected visual acuity (BSCVA) whereas five LASIK eyes (12.2%) lost two or more lines of BSCVA.  Perhaps one of the most important statistics, only one Verisyse™ eye (2.3%) was disturbed by severe night glare versus six LASIK eyes (14.6%).  In the case of glare with the Verisyse™ IOL, this lens was exchanged for a larger size optic (5mm optic exchanged for 6 mm optic).  In parallel with this, the contrast sensitivity measurement decreased by two or more lines in two (4.7%) of the Verisyse™ eyes versus six (14.6%) of the LASIK eyes. 

The authors of this study concluded with the following: “Better uncorrected and spectacle-corrected visual acuity and contrast sensitivity, a lower enhancement rate, and exchangeability are the main advantages of Artisan (former name for the Verisyse™ IOL) lens implantation.  Thirteen (72.2%) of the 18 patients who received the Artisan lens in one eye and LASIK in the other preferred the Artisan lens to the LASIK eye, mainly because of the better quality of vision.”

In a European study, twenty-five patients with myopia between –8.0 and –12.0 diopters received a Verisyse™ IOL in one eye and LASIK in the other eye[xii].  In this investigation, the Verisyse™ IOL showed a significantly better safety index, that is, less loss of BSCVA.  Also, the best corrected visual acuity and subjective evaluation of quality of vision were both better in the eyes that received the Verisyse™ IOL. 

Staar Surgical’s Visian ICL™ (Implantable Collamer Lens)

On December 22, 2005, the U.S. FDA approved Staar Surgical Company’s

Visian ICL™, which is the second phakic IOL to receive FDA approval in the United States.  At this time, there is a relative paucity of information regarding this lens outside of the FDA studies.  The FDA website, at least at our “press time”, did not have the summary of safety and effectiveness or labeling documents available.

The Visian ICL™ is a phakic IOL that is permanently implanted in the eye behind the iris and in front of the natural lens, unlike the Verisyse IOL™, which is implanted in front of the iris and surgically attached to the iris tissue.  The Visian ICL™ is intended to correct moderate to severe nearsightedness.  As with any phakic IOL, the natural lens of the eye is left undisturbed.   

The Visian ICL™ works like any typical IOL, that is, by bending light rays to allow better focusing on the retina.  The IOL power is determined using the patient’s refraction (glasses correction), axial length of the eye, and corneal curvature.

This lens is approved for the correction of myopia from –3.0 to –20.0 diopters (D) with less than or equal to 2.5D of astigmatism.  Interestingly, it was only FDA approved for adults between the ages of 21 and 45 years of age with a stable refractive history (less than or equal to 0.5 D of change for one year prior to implantation).  Patients must have an anterior chamber depth (the space between the back of the cornea and the front of the eye’s natural lens) of 3.00 mm or greater.  Below is a diagrammatic look at the lens from the front and side views:

Visual Outcomes and Quality of Vision with the Visian ICL™

In the clinical studies completed as part of the FDA controlled trials, 294 patients were implanted with the Visian ICL™.  Ninety-five percent of those patients had 20/40 or better vision and 59% had 20/20 or better vision, three years after implantation[xiii]. 

What is even more impressive is the quality of vision that patients implanted  with the Visian ICL™ had.  In a comparison of induced visual aberrations, ten patients implanted with the ICL were compared with ten patients that had undergone LASIK.  Both groups had pre-operative myopia between –8.0 and –10.0 diopters.  Wavefront analysis was used to assess the visual aberrations, which, for those who are interested, included measurements of spherical aberration and coma.  Spherical aberration in the group implanted with the ICL measured only 0.13 microns, on average, versus 0.39 microns in the LASIK group.  Coma measured only 0.22 microns, on average, in the ICL group, versus 0.46 microns in the LASIK group[xiv].  For the statistically inclined, the coma and spherical aberration results combined have a significance of p<0.0001.  For those who just want the “bottom line”:  Patients implanted with the ICL had far better quality of vision than those who had LASIK, in this study.  Keep in mind that these are patients who had rather severe myopia, that is, between –8.0 and –10.0 diopters.

The Visian ICL™ is Highly Biocompatible

The Visian ICL™ is made of Staar’s proprietary, highly biocompatible Collamer® material, noted to leave eyes exquisitely quiet, that is, non-inflamed, after surgery.  In fact, the collagen component in Collamer actually repels protein molecules that are attracted to silicone lenses, which may cause a type of scarring called fibrosis.  Instead, the collagen in Collamer attracts a monolayer of fibronectin that literally isolates the lens from the immune system.  According to one study, this results in “exquisitely quiet eyes… even in uveitis and diabetic patients”[xv]. 

Less Invasive Surgery with the Visian ICL™

The surgery required to implant this lens is less invasive than that required to implant the Verisyse™ IOL for two reasons: 1) The Visian ICL™ is a foldable lens and therefore requires an incision size that is only about 50% the size required to implant the Verisyse™ IOL, and 2) the Visian ICL™ is placed behind the iris rather than attached to the anterior (front) surface.  According to Staar Surgical, the fact that the Visian ICL™ is placed behind the iris provides “a more aesthetically pleasing outcome”, apparently because the lens is minimally visible, whereas the Verisyse™ IOL is somewhat visible upon close inspection with the naked eye[xvi].  By the time of U.S. FDA approval, the Visian ICL™ had already been successfully implanted in 40,000 eyes worldwide. 

Optical and Mechanical Advantages of the Visian ICL™

According to Staar Surgical’s website, “Collamer has a molecular size of only 100nm (nanometers), shorter than the wavelength of visible light.  This results in an optimal refractive index for maximum transmission and minimum glare and halo.  The collagen copolymer Collamer provides ideal flexibility for injectable use, unfolding gently and predictably in the eye”[xvii].

As with the Verisyse™ IOL, the Visian ICL™ should not be implanted in patients who are pregnant or nursing and a specific minimum corneal endothelial cell density is necessary in order to be considered a candidate. 

Conclusions

If you looked at the numbers of patients who were 20/20 or better in the studies reviewed and were disappointed, let me give you a little further perspective.  The patients who underwent implantation with the Verisyse™ IOL and the Visian ICL™ in these studies were extremely myopic.  Look at the numbers again… These patients were –8.0 to –20.0 diopters myopic in the Verisyse study!  Less than 2% of the population is greater than –6.0 diopters myopic and only about 0.2% of the population is above –9.0 diopters of myopia.  Without any correction, these patients can hardly count fingers held in front of them at the distance that you and I would hold a book or read this page!  Again, one must keep perspective here.

With respect to the issue of corneal endothelial cell density loss that is associated with implantation of the Verisyse ™ lens – the jury is obviously still out on that one.  The endothelial cell loss is certainly concerning, but it isn’t scary to me and I wouldn’t hesitate to have the lens implanted in my eyes if I were a candidate.  Again, as mentioned, if the endothelial cell loss continues at a rate of 1.8% per year or more, then as many as 50% of those cells could be lost over a 25 year period, but this still may not mean corneal decompensation.  Furthermore, one would have to consider the age at implantation.  If the Verisyse™ phakic IOL were implanted for 10 or 20 years and then required explantation (removal) due to the endothelial cell loss, perhaps a better alternative would be available then.  In fact, isn’t it likely that it will?  With the explosion of technology in this field, I would answer a resounding “yes”!  Perhaps the Visian ICL™ had a lesser degree of associated endothelial cell loss, but I’ve been unable to acquire this data from Staar Surgical or from the FDA’s website. 

In my opinion, if I had myopia above –8.0 or –9.0 diopters, and I was intent on decreasing my dependence on glasses or contact lenses, I would definitely choose either the Verisyse™ phakic IOL or the Visian ICL™ - period.  In fact, I feel strongly that one of these phakic IOLs is the best refractive surgery procedure for those who are this myopic – and age is not really a factor, assuming the eye is healthy.  However, it is important to note that the Visian ICL™ was only FDA approved for individuals between 21 and 45 years of age.  It could certainly be implanted in individuals above the age of 45, however, this is considered on “off-label” use, which is still perfectly legitimate and fine.  This simply means that this age group was not evaluated in the FDA trials.

If you were to ask me which one of these hakic IOLs I believe is best, at this time I do not have an answer for that, partly because of incomplete data available to me on the Visian ICL™.  However, I believe that the FDA wouldn’t have approved the Visian ICL™ had it not shown results comparable to or better than competing technology, that is, the Verisyse™ IOL.  Either lens obviously has an excellent track record in a capable surgeon’s hands.  I would discuss this issue with a qualified refractive surgeon, because his or her comfort level and experience with either of the lenses would be of utmost importance.     

So what if you’re in the –5.0 to –8.0 diopter range?  Well, you definitely have more options, but only a thorough exam by a well-rounded refractive surgeon could determine if you were a good candidate for LASIK, Epi-LASIK, or IntraLASIK (please see Chapter Seven if you’ve not familiar with these terms).  Also, if you’re in the –5.0 to –8.0 diopter range, and you’re over 40 or 50, you might also want to consider refractive lens exchange (see Chapter Thirteen).  Please see the “refractive surgery Decision Algorithm” in Chapter Six.  This is definitely an area of overlap and it is probably frustrating to you, if you fall in this range, that I’m not suggesting a single definitive procedure for you.  Please don’t look at this in a negative light; it is really a benefit that you have more options.  But it is a difficult choice.  No one can make that decision for you except you and your refractive surgeon.  I would talk it over with him or her before you come to a decision.