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Roibeard O’hÉineacháin
in Rome

THE combination of the Artisan refractive IOL and excimer laser corneal ablation may be a safer and more predictable approach for the correction of high ametropia than either technique on its own, a number of ophthalmologists have claimed.

“Laser refractive surgery is effective for the correction of low-medium, medium-high myopia and astigmatism and phakic IOLs provide very good results for both high and extreme myopia. If we combine the two techniques we can correct a wider range of refractive errors,” said Italian specialist Luca Vigo MD at the 7th ESCRS Winter Refractive Surgery meeting.

Dr Vigo reported the results of a study involving 44 myopic eyes with a mean spherical equivalent (SE) of -12.59 D
(-8.5 D to -15.5 D), which underwent iris-fixated phakic IOL implantation (Artisan) to correct the spherical compound of the refractive error, and Lasik two to three months later to correct the astigmatism and residual myopia.

One year after the second procedure, 68.4% of eyes were within ± 0.50 D of intended correction and 93.4% were within ± 1.0 D.
In addition, nearly half the eyes achieved an uncorrected visual acuity of 20/20 or better and 83% achieved 20/32 or better. More than half the eyes gained one to four lines of BSCVA and only one eye lost one line of BSCVA.

“All patients were very satisfied and reported that their vision was comparable to that of preoperative vision with contact lenses. None of the patients complained of night vision problems,” Dr Vigo said.
He and his colleagues used the non-toric 6.0mm optic model of the Artisan lens in all eyes. To perform the subsequent Lasik procedures, they used the SKBM microkeratome and the Alcon Autonomous Ladarvision excimer laser.

All phakic IOL surgeries were uneventful, although one patient had an increased IOP one day after surgery and requested the IOL be removed.
The Lasik procedures produced no major complications. Moreover, the endothelial cell count remained unchanged after the procedure, indicating that the pressure on the cornea during flap creation did not bring the endothelium into contact with the IOL, he pointed out.

Dr Vigo noted that while in theory phakic IOLs should be able to correct myopia up to –23 D, in practice that is often not the case. That is because of several potentially limiting factors, such as errors in IOL power calculation and incision-induced astigmatism.

In the case of the Artisan lenses, to correct astigmatism and refractive errors above –15.50 D the lens must be no more than 5.0mm in diameter. The smaller optical diameters can cause halos and night vision problems in patients with large pupils.
The advantages of the bioptic approach therefore include a larger optical zone and better night vision. Furthermore, the toric IOLs for astigmatism are more difficult to implant because they require the axis of haptic enclavation to be very close to the axis of cylinder.

The main disadvantage of the bioptic approach is the interval between surgeries and the requirement that patients undergo two separate procedures, Dr Vigo said.
“The combined procedure of phakic IOL implantation and Lasik to correct high myopia with high astigmatism provided high predictability and efficacy, without side-effects or complications with optimal visual performance. And that is why this is our procedure of choice,” Dr Vigo said.

In patients who are unsuitable for Lasik, a bioptics approach combining the Artisan IOL with Lasek may be a useful alternative, said Portuguese ophthalmologist, Joaquim Murta MD.

He conducted a study of 32 eyes of 18 patients with a mean SE of -16.2 D who underwent Artisan phakic IOL implantation followed by Lasek.
The patients in the study included 10 men and eight women with a mean age of 27.7 years, within a range of 21 to 42 years. Their preoperative mean sphere was -15.3 D, within range of 10.5 to 25.5 D, and their mean preoperative cylinder was -1.7 D, ranging between 0.0 D and 5.0 D.

All patients underwent implantation of an Artisan phakic IOL. Two to three months later they underwent Lasek to correct a mean residual spherical error of –0.6 D and a mean cylinder of –1.4 D.

Nearly 70% of patients had postoperative UCVA of 20/30 or better and some 28% of cases gained two or more lines of BCVA at three months follow-up; at six months these values increased to 90% and 30% respectively. The UCVA was 20/25 or better in 38% and 20/20 or better in 22%.

In 32% of eyes, UCVA was 20/40 or worse. None of the eyes lost any lines of BSCVA, while 34% gained one line, 22% gained two and 6.0% gained three lines.
Refraction stabilised in all eyes four to eight weeks after Lasek. Nearly 90% were within +1.0 D of emmetropia and 71.9% were within + 0.5 D, he added.
Dr Murta and his colleagues created the epithelial flap with a 9.0mm trephine and a 15% ethanol solution applied for 20 to 30 seconds.

They peeled the flap back at the 12 o’clock position and performed the corneal ablation with a Planoscan 217 C laser. Patients wore bandage contact lenses for five days and received topical antibiotics and steroids for 10 days.
Complications related to phakic IOL implantation included one case of hyphaemia and one case of giant cells on the surface of the lens. Lasek complications included epithelial defects on the first day after surgery in 72% of cases and grade one haze in 12.5% of cases.

Dr Murta said that patients most suitable for Lasek/Artisan bioptics include those with a higher risk of developing flap complications. Such individuals would include those with small palpebral fissures, deep-set eyes, corneal basement membrane dystrophy, thin corneas, extremely steep or flat corneas and patients more prone to corneal trauma.
"This is a preliminary work but we think Artisan phakic IOL implantation combined with Lasek is an accurate, stable and safe method to treat high myopia and myopic astigmatism," Dr Murta said.

The Artisan phakic IOL can also be useful as a secondary procedure in patients who have an unsatisfactory outcome after previous refractive surgery or PK and are unsuitable candidates for excimer laser surgery, said another Portuguese specialist, Fernando Vaz MD.

Patients who might be deemed unsuitable for secondary Lasik, PRK or Lasek include those with residual myopia after primary Lasik if the cornea is too thin, those with residual ametropia after PRK with moderate haze, those with those with residual ametropia after PK and keratoconus patients with important myopia after intracorneal ring implantation, Dr Vaz explained.
“We chose to implant the Artisan IOL in such cases because we don’t want to solve one complication only to induce another one,” he added.

Dr Vaz presented a retrospective study of 30 eyes of 21 patients who underwent implantation of an Artisan IOL to correct residual myopia ranging from –1.0 D to –19 D and hyperopia ranging from +4.0 D to + 6 D.
Two-thirds of cases were within 1.0 D of emmetropia at final follow-up. The same proportion gained lines of BCVA at final follow-up and none of the eyes lost any lines.

The patients included 10 men and 11 women with a mean age of 34 years. Their primary procedures were Lasik in seven eyes, PRK in six, PK in 10, ALK in two, intracorneal ring segments in two and RK in three eyes.
Dr Vaz implanted the 5.0mm myopic Artisan in 14 eyes, the 6.0mm myopic Artisan in 11 eyes and the hyperopic Artisan in five eyes and based his power calculations on the manufacturer tables.

“Artisan is safe and effective as a secondary procedure when no more corneal surgery is advisable. It is our method of choice for solving important residual or induced ametropia after corneal surgery where there is myopia greater than - 5.0 and hyperopia above +3.00,” Dr Vaz said.

Luco Vigo MD
Carones Ophthalmology Centre, Milan, Italy
Email: fcarones@carones.com

Joaquim Murta MD
University Hospital, Coimbra, Portugal
Email: murta@mail.telepac.pt

Fernando Vaz
Hospital Santo Antonio, Portugal
Email: cliofvaz@hotmail.com

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