Iris-claw Phakic Intraocular Lens for High Myopia

Dependency of endothelial cell loss on anterior chamber depth within first 4 years after implantation of iris-supported phakic intraocular lenses to treat high myopia

PURPOSE

To evaluate the effect of the anterior chamber depth (ACD) on the central corneal endothelial cell density (ECD) in eyes after implantation of an iris-fixated phakic intraocular lens (pIOL).

SETTING

Department of Ophthalmology, Goethe-University, Frankfurt, Germany.

DESIGN

Retrospective nonrandomized case series.

METHODS

An Artisan pIOL was implanted in eyes of highly myopic patients. Follow-up examinations at 1, 12, 24, 36, and 48 months included evaluation of ECD and adverse events. Three cohorts based on the ACD were established and their ECDs compared. All eyes had 1-year and 4-year postoperative ECD measurements available. Statistical analysis included linear regression analysis to evaluate the influence of ACD on ECD.

RESULTS

The study comprised 95 eyes (52 patients). Four years after surgery the mean spherical equivalent changed from -11.06 diopters (D) ± 4.77 (SD) to -0.42 ± 0.47 D. Severe adverse events were not detected. There was a significantly higher ECD loss after 4 years in patients with an ACD of less than 3.00 mm than in those with an ACD greater than 3.40 mm (-224 cells/mm²) (P < .01). There was no significant difference in ECD between eyes with an ACD of 3.00 to 3.39 mm and eyes with an ACD less than 3.00 mm (P = .23) or more than 3.40 mm (P = .08).

CONCLUSIONS

The iris-claw pIOL precisely and safely corrected high myopia. However, the loss in ECD can be considerable. Establishing stricter exclusion criteria for ACD might reduce this loss.

FINANCIAL DISCLOSURE

Proprietary or commercial disclosures are listed after the references.

Refractive lens exchange versus phakic intraocular lenses

PURPOSE OF REVIEW

To review the evidential basis of current practice in refractive lens exchange (RLE) vs. phakic intraocular lens (pIOL).

RECENT FINDINGS

Visual outcomes after pIOLs are better than RLE. With RLE, there still remain risks of retinal detachment, cystoid macular oedema, glare, halos and posterior capsule opacification. With pIOLs, risks include pigment dispersion, cataract formation, glaucoma and inflammation. The decision to choose between either is broadly based on age and type of refractive error, and the choice follows thorough evaluation and counselling taking into consideration patient's needs and expectations.

SUMMARY

With advancing technology, newer IOL models for RLE and phakic correction are becoming available. pIOLs provide better visual outcomes for distance correction and currently do not provide near-vision correction possible with RLE.

Five-year follow-up after anterior iris-fixated intraocular lens implantation in phakic eyes to correct high myopia

PURPOSE

To evaluate the 5-year follow-up of safety, efficacy, predictability, stability, and complications of anterior iris-fixated phakic intraocular lens (pIOL) implantation to correct high myopia, and patients' satisfaction after implantation.

DESIGN

Prospective, nonrandomized, and comparative (self-controlled) trial.

METHODS

A prospective clinical trial of 84 eyes of 43 patients with high myopia was conducted. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, endothelial cell count, intraocular pressure (IOP), anterior chamber depth, slit lamp biomicroscopy, and indirect ophthalmoscope were measured preoperatively and postoperatively.

RESULTS

At the 5-year follow-up, UCVA was significantly improved, with 85.7% of eyes reaching 20/25 or better. No eyes experienced a loss in BSCVA, and 71.4% gained one or more lines of their preoperative BSCVA. There was a significant reduction in spherical errors in all patients after operation. Loss of endothelial cells was observed 3 years after operation and no more loss was observed 4 years after operation in statistical analysis. No increase in IOP was observed 5 years after operation in statistical analysis. No intraoperative complications were observed in this study. However, pigment precipitates of varying intensities on the lens optic were noted in all patients 1 day after operation, and only five eyes were observed to have the pigment residual five years after operation.

CONCLUSION

At the 5-year follow-up, the implantation of the anterior iris-fixated pIOL was proved to be effective, predictable and capable of reversibility to correct high myopia in phakic eyes. It was a safety addition to the laser refractive surgery. However, longer follow-up with larger numbers of patients is still necessary to evaluate long-term complications.

Prominent decrease of superior midperipheral endothelial cell density after iris-fixated phakic intraocular lens implantation

PURPOSE

To evaluate changes in endothelial cell density (ECD) in the corneal region after implantation of an iris-fixated phakic intraocular lens (PIOL).

METHODS

Forty-five eyes of 25 myopic patients implanted with Artisan iris-fixated PIOLs (Ophtec BV) and 30 eyes of 15 myopic controls were enrolled. Corneal ECD and the distance between endothelium and the PIOL optic were evaluated in five different regions (central, nasal, superior, temporal, and inferior) using noncontact specular microscopy and rotating Scheimpflug imaging.

RESULTS

In PIOL-implanted patients, significant differences between the ECD in the superior region, compared with the lowest ECD in any region, and the ECD of the central region, compared with that of the region with highest ECD, were evident. When PIOL-implanted eyes were divided based on time since operation, a significant difference was observed only in patients for whom at least 48 postoperative months had elapsed. In untreated myopic controls, the greatest ECD was observed at the superior cornea. The distance between the central corneal endothelium and PIOL was significantly longer than that of the peripheral locations.

CONCLUSIONS

The extent of ECD decrease was not consistent throughout the cornea after implantation of an iris-fixated PIOL. Therefore, ECD measurement not only at the corneal center but also at midperipheral corneal locations, especially in the superior cornea, may be important in patients with irisfixated PIOLs.

Late onset secondary cataract following implantation of an iris-fixated phakic intraocular lens

PURPOSE

To report a case of bilateral late onset anterior cortical cataract following implantation of an iris-fixated phakic intraocular lens (pIOL).

METHODS

Single observational case report.

RESULTS

Three and a half years following uncomplicated consecutive implantation of iris-fixated pIOL in both eyes, anterior cortical cataract changes inferiorly emanating from the site of enclavation of the lens in the right eye were noted. By 7 years after implantation, anterior cortical cataract changes were seen emanating from the enclavation sites superiorly and inferiorly in both eyes. These cataracts did not cause any loss of corrected distance visual acuity.

CONCLUSIONS

This case demonstrates that a potential complication of an iris-fixated pIOL is late onset secondary cataract formation.

Late-onset nontraumatic dislocation of anterior chamber phakic intraocular lens

Long-term stability of the position of phakic intraocular lenses (pIOLs) is important in maintaining visual acuity as well as avoiding injury to the local tissues. We report a case of late nontraumatic dislocation of an iris-fixated pIOL, with subsequent successful repositioning.

Late-onset decentration of iris-fixated phakic intraocular lenses: a case series

PURPOSE

To investigate late-onset downward decentration of iris-fixated phakic intraocular lenses (pIOL) resulting from progressive shifting of the haptics through the iris and its influence on the position of the pIOL and the amount of enclavated iris tissue.

DESIGN

Institutional, prospective, observational case series.

METHODS

Six patients (9 eyes) from among 368 eyes had 1 shifted haptic during long-term follow-up. Anterior segment optical coherence tomography (AS-OCT) was used to measure the distance between the edges of the pIOL and the corneal endothelium. Slit-lamp photography imaged the pIOL after implantation and after decentration. The images were analyzed to determine decentration and amount of iris tissue at the enclavation sites.

RESULTS

Shifting of the haptics occurred in 2.4% and was discovered at a mean follow-up of 4.8 years (range, 3 to 7 years). Mean downward decentration was 0.28 +/- 0.15 mm. Mean edge-distances on the nasal, temporal, superior, and inferior side were 1.71 +/- 0.30 mm, 1.86 +/- 0.31 mm, 1.86 +/- 0.31 mm, and 1.58 +/- 0.34 mm, respectively. Mean enclavated iris tissue on the nasal and temporal side was smaller after decentration when compared with that directly after surgery (P = .033 and P = .017, respectively). Shifting of the haptics did not result in a decreased uncorrected and best-corrected visual acuity.

CONCLUSIONS

Late-onset downward decentration resulting from progressive shifting of the haptics occurred in 2.4% and was associated with a decrease in enclavated iris tissue. AS-OCT showed a mean distance between the edge of the pIOL and the endothelium greater than the advised safety distance of 1.5 mm.

Case of late-onset corneal decompensation after iris-fixated phakic intraocular lens implantation

A 48-year-old myopic patient with bilateral anterior chamber depth of 3.1 mm and endothelial cell density (ECD) of 2525 cells/mm(2) and 2638 cells/mm(2) preoperatively had bilateral implantation of an Artisan iris-fixated phakic intraocular lens (pIOL). Five years postoperatively, unilateral corneal stromal edema was seen in a circumscribed area overlying the temporal ridge of the pIOL in the right eye; the ECD was 1631 cells/mm(2) and the pachymetry, 586 microm. Explantation of the pIOL was refused by the patient. Seven years postoperatively, the ECD was 413 cells/mm(2) in the right eye and corneal decompensation occurred. The progressive unilateral endothelial loss was explained by excessive rubbing of the eyes because of chronic itching and an anterior shift of the pIOL over the 7 years as demonstrated by anterior optical coherence tomography.

Influence of anterior chamber morphometrics on endothelial cell changes after phakic intraocular lens implantation

PURPOSE

To analyze the position of iris-fixated phakic intraocular lenses (pIOLs) using anterior segment optical coherence tomography (AS-OCT) and evaluate the effect of anterior chamber morphometrics on endothelial cell changes.

SETTING

Department of Ophthalmology, Academic Hospital Maastricht, The Netherlands.

METHODS

In this cross-sectional study, AS-OCT was used to measure the distances from the center and the edges of the pIOL to the corneal endothelium in 242 eyes with various models of myopic pIOLs. Endothelial cell measurements were performed preoperatively and at each follow-up examination.

RESULTS

The mean follow-up was 34.1 months+/-24.7 (SD) (range 3 months to 7 years). The mean distance between the edge of the pIOL and the endothelium was 1.37+/-0.22 mm. Although this distance was smaller than the safety value of 1.50 mm in 68.6% of the eyes, no eye developed corneal decompensation. There was a significant endothelial cell density (ECD) loss of 1.28%+/-8.46%, 3.25%+/-8.24%, and 5.02%+/-10.40% at 2 years, 5 years, and 7 years, respectively. Linear mixed-model analysis predicted a yearly ECD loss of 0.98% for a mean edge distance of 1.37 mm, 0.15% for an edge distance of 1.59 mm (mean plus 1 SD), and 1.80% for an edge distance of 1.15 mm (mean minus 1 SD).

CONCLUSIONS

A shorter distance between the edge of the pIOL and the endothelium was significantly associated with higher ECD loss. For safety reasons, the postoperative examination should include long-term evaluation of the anterior chamber morphometrics in addition to ECD counts.

Long-term Follow-up of Endothelial Cell Change after Artisan Phakic Intraocular Lens Implantation

OBJECTIVE

To report endothelial cell densities (ECDs) and their correlation to anterior chamber depth (ACD) after implantation of the Artisan intraocular phakic lens.

DESIGN

Prospective observational case series.

PARTICIPANTS

Three hundred eighteen eyes of 173 myopic patients treated with the Artisan iris-fixated phakic intraocular lens (IOL).

METHODS

Eyes with an ACD ranging between 2.89 and 4.5 mm were implanted with the Artisan phakic IOL. Endothelial cell density measurements were performed preoperatively and at each follow-up examination using a noncontact specular microscope.

MAIN OUTCOME MEASURES

Endothelial cell density (cells per square millimeter).

RESULTS

Follow-up ranged between 1 (82 eyes) and 7 years (13 eyes) (mean, 35.3+/-20.7 [standard deviation] months per eye). After 3 years, there was a significant loss in ECD (P< or =0.03). At 5 years, mean observed endothelial cell loss was 8.3% (5.3% corrected for a natural endothelial cell loss of 0.6% a year). Endothelial cell density loss remained progressive throughout our follow-up period. After 3 years, a significant negative correlation between ACD and endothelial cell loss was revealed (P< or =0.03). Patient age, gender, refractive error, incision size, and side of the eye were not correlated to ECD loss. All corneas remained clear throughout the study.

CONCLUSION

After 3 years, a significant ECD loss was revealed. This ECD loss was significantly negatively correlated to the ACD. We therefore suggest that eyes just meeting the minimum ECD requirement have greater ACDs to compensate for possible greater endothelial cell loss and that patients with shallow anterior chambers have higher ECDs. Artisan phakic lens implantation in young eyes narrowly meeting the minimum criteria of endothelial cell density (2,000 cells/mm(2)) and ACD (2.6 mm) should perhaps be reevaluated, due to longer exposure to higher rates of endothelial cell loss.

[Toric phakic intraocular lenses]

After more than 3 years of follow-up, the satisfactory results achieved with the toric iris-fixated phakic intraocular lens (IOL) mean we can regard implantation of this lens as a procedure with the potential to provide safe, predictable, effective and stable correction of astigmatic errors, providing patients are carefully selected and receive adequate preparation for surgery. The iris-fixated toric phakic IOL (Verisyse, Advanced Medical Optics; Artisan, Ophtec) is a PMMA lens with a total diameter of 8.5 mm and an optic diameter of 5 mm. It has a spherical anterior and a toric posterior surface. Its refractive power ranges from -2 dpt to -21 dpt for myopia and from +2 dpt to +12.5 dpt for the correction of hyperopia. Cylindrical correction is available from 2 dpt to 7.5 dpt. The Visian toric implantable Collamer lens (Staar) differs in that it is foldable and can be inserted through a very small incision of about 2.8 mm. It is placed in front of the natural lens in the ciliary sulcus. The aim of implanting these phakic IOLs is to correct the entire refractive error, meaning both the spherical and the astigmatic error, in a single step. Different lens models are available, and the selection depends on the direction of the cylinder axis and the anatomical situation, among other things.

Severe endothelial cell loss following uneventful angle-supported phakic intraocular lens implantation for high myopia

Endothelial decompensation is a serious complication of phakic intraocular lens (pIOL) implantation and is a major concern during the postoperative period. We report 3 eyes in which the same foldable angle-supported pIOL was implanted to correct high myopia. Rapid and severe postoperative endothelial cell loss occurred in all 3 eyes. An over-sized pIOL that induced excessive vaulting into the anterior chamber was the main risk factor. In 2 eyes, the pIOL was explanted uneventfully; 1 eye required Descemet's stripping automated endothelial keratoplasty because of total endothelial decompensation. These cases illustrate the importance of accurate sizing of foldable angle-supported anterior chamber pIOLs to avoid excessive vaulting. They also highlight the importance of regular follow-up and preventive pIOL explantation as soon as significant endothelial cell loss is detected.

Long-term endothelial changes in phakic eyes after Artisan intraocular lens implantation to correct myopia: five-year study

PURPOSE

To evaluate long-term endothelial cell changes in eyes that had implantation of an iris-fixated phakic Artisan intraocular lens (IOL) for moderate to high myopia.

SETTING

Casa di Cura Villa Igea, Ancona, Italy.

METHODS

Forty-nine eyes of 30 patients having implantation of Artisan IOL for moderate to high myopia were prospectively examined. Preoperative specular microscopy and serial postoperative specular microscopy (Noncon Robo SP 8000, Konan Medical) were performed to evaluate endothelial cell changes over 5 years. Endothelial cell images were collected in the central region of the cornea before surgery and 4, 12, 24, 36, 48, and 60 months after surgery. The endothelial cell density (ECD), coefficient of variation, and percentage of hexagonal cells were determined.

RESULTS

Preoperatively, the mean ECD was 2616 cells/mm(2) +/- 347 (SD), the mean coefficient of variation was 39.6% +/- 4.7%, and the mean percentage of hexagonal cells was 49.2% +/- 6.7%. The mean endothelial cell loss from preoperatively was 2.3% at 4 months, 3.5% at 12 months, 4.7% at 24 months, 6.7% at 3 years, 8.3% at 4 years, and 9.0% at 5 years. Five years after surgery, the mean coefficient of variation was 35.9% +/- 6.9% (P = .1946) and the percentage of hexagonal cells was significantly higher (mean 54.7% +/- 10.3%) (P = .087).

CONCLUSIONS

Continuous endothelial cell loss was observed after surgery during a 5-year follow-up, especially during the first 2 years. A decrease in the coefficient of variation and an increase in the percentage of hexagonal cells were observed over time, reflecting the increasing stability and remodeling of the corneal endothelial cells 5 years postoperatively.

Long-term Study of Artisan Phakic Intraocular Lens Implantation for the Correction of Moderate to High Myopia

PURPOSE

To determine the long-term performance of the Artisan phakic intraocular lens (PIOL) for the correction of myopia.

DESIGN

Long-term (10 years) retrospective follow-up study.

PARTICIPANTS

Eighty-nine eyes of 49 patients who underwent Artisan PIOL implantation for the correction of myopia.

METHODS

Comparisons were made between preoperative clinical data and the clinical data at 1, 6, and 10 years after surgery.

MAIN OUTCOME MEASURES

Refractive stability, refractive predictability, safety, efficacy, best-corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), intraocular pressure, intraoperative problems, corneal endothelial cell density, corneal endothelial cell loss, and glare levels were evaluated.

RESULTS

The mean spherical equivalent (SE) after 10 years was -0.70+/-1.00 diopters (D; range, -4.00 to 2.00 D), with no significant change in mean SE between 1, 6, and 10 years. At 10 years, 68.8% of all eyes were within 1.0 D of the intended correction. At 10 years, 31.2% (n = 24) gained 1 or more Snellen lines of BCVA and 2.6% (n = 2) lost more than 2 Snellen lines of BCVA; 93.3% reached a BCVA of 20/40 or better, and 82.0% reached a UCVA of 20/40 or better. The mean intraocular pressure remained stable and was 15.5+/-3.5 mmHg (range, 7-25 mmHg) at 10 years. The mean endothelial cell loss was -8.86+/-16.01% (range, -51.69% to 34.43%) at 10 years.

CONCLUSIONS

Long-term results demonstrate that the implantation of an Artisan PIOL for the correction of moderate to high myopia is a stable, predictable, and safe method when strict inclusion criteria for surgery are applied. There was no significant loss of corneal endothelial cells and no reports of long-term glare.

Endothelial Cell Loss After Toric Iris-fixated Phakic Intraocular Lens Implantation: Three-year Follow-up

PURPOSE

To study quantitative changes in endothelial cell count after implantation of the toric iris-fixated phakic intraocular lens.

METHODS

A prospective, non-randomized, self-controlled clinical trial was conducted of 40 eyes (28 myopic, 12 hyperopic) of 23 patients with high ametropia and astigmatism. Non-contact computer-assisted endothelial microscopy was performed before and 1, 2, and 3 years after surgery.

RESULTS

In the myopic group, mean preoperative endothelial cell count was 3179 +/- 531 cells/mm2 (range: 1800 to 3900 cells/mm2). The mean intra-individual endothelial cell loss was -1.83 +/- 2.25% (range: -9.09% to 0%) in the first year; -1.83 +/- 2.95% (range: -7.74% to 3.80%) in the second year; and -3.20 +/- 4.43% (range: -14.25% to 1.91%) three years after surgery, compared to preoperative values. In the hyperopic group, mean preoperative endothelial cell count was 3107 +/- 125 cells/mm2 (range: 2932 to 3300 cells/mm2). The mean endothelial cell loss was -1.63 +/- 1.76% (range: -3.23% to 1.67%) in the first year; -0.05 +/- 1.25% (range: -1.65% to 1.75%) in the second year; and -2.88 +/- 2.03% (range: -5.33% to -0.13%) three years after surgery, compared to preoperative values.

CONCLUSIONS

Annual cumulative cell loss was -1.9% for the myopic group and -1.6% for the hyperopic group, which is two to three times greater than physiological annual cell loss in normal eyes without surgery. An annual endothelial cell count analysis is highly recommended in every patient after iris-claw lens implantation to detect potential progressive cell loss at an early stage.

Long-Term Follow-Up of the Corneal Endothelium After Artisan Lens Implantation for Unilateral Traumatic and Unilateral Congenital Cataract in Children

PURPOSE

To retrospectively estimate the long-term corneal endothelial cell loss in children after perforating corneal trauma and implantation of an iris-fixated anterior-chamber intraocular lens (IOL), either the Artisan aphakia lens or the Artificial Iris Implant, and to compare this corneal endothelial cell loss to that in children who received an Artisan aphakia lens to correct aphakia after cataract extraction for unilateral congenital cataract.

METHODS

A retrospective study was performed, evaluating the charts and endothelial photographs of 6 patients with unilateral traumatic cataract, with a mean age at IOL implantation of 9.5 years (range: 5.8-12.8 years) and a mean follow-up after IOL implantation of 10.5 years (range: 8.0-14.7 years), and of 3 children who were operated on for unilateral congenital cataract at a mean age of 2.7 years and who received an Artisan aphakia IOL, with a mean follow-up after IOL implantation of 9.5 years (range: 4.7-14.5 years). Parameters that were studied were central endothelial cell density (CECD) in both the operated and the normal eye at the last follow-up visit, percentage of cell loss in the operated eye compared with the normal eye, and length and location of the corneal scar in the injured eye.

RESULTS

: In the traumatic cataract group, CECD was, on average, 41% (range: 22%-58%) lower in the operated eye (1.647 +/- 322 [SD] cells/mm) than the normal eye (2.799 +/- 133 cells/mm). A significant negative linear correlation was found between the length of the corneal perforation scar and CECD. In the congenital cataract group, no statistical difference in CECD was found between the operated (3.323 +/- 410 cells/mm) and the unoperated (3.165 +/- 205 cells/mm) eye.

CONCLUSION

Endothelial cell loss 10.5 years after iris-fixated IOL implantation for traumatic cataract was substantial and related to the length of the corneal scar of the original trauma. In children operated on for congenital cataract, no difference was found in CECD in the operated and unoperated eyes 9.5 years after Artisan aphakia IOL implantation.

Iris-fixated toric phakic intraocular lens: Three-year follow-up

PURPOSE

To evaluate the 3-year safety, efficacy, predictability, and stability of iris-fixated toric phakic intraocular lens (pIOL) implantation for the correction of myopia or hyperopia with astigmatism.

SETTING

Department of Ophthalmology, Johannes Gutenberg University, Mainz, and Department of Ophthalmology, University Clinic, Bochum, Germany.

METHODS

A prospective clinical trial of 40 eyes of 23 patients with high ametropia and astigmatism was conducted. Best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity, refraction, astigmatism, intraocular pressure, slitlamp biomicroscopy, and indirect ophthalmoscopy were measured preoperatively and postoperatively.

RESULTS

Of the 40 eyes, 28 were myopic and 12 were hyperopic. Three years postoperatively, 70% of eyes were within +/-1.00 diopter (D) of the targeted refraction. In the myopic group, mean preoperative BSCVA was 20/40 and improved postoperatively to 20/25. Sixty-six percent of eyes gained 1 or more lines from the preoperative BSCVA. The mean cylinder decreased from -3.58 D +/- 1.26 (SD) preoperatively to -1.15 +/- 1.01 D postoperatively. In the hyperopic group, preoperative BSCVA was 20/25 and improved to 20/20 postoperatively. Thirty-six percent of eyes gained 1 or more lines from the preoperative BSCVA. The mean cylinder decreased from -3.37 +/- 0.88 D to -1.53 +/- 0.69 D postoperatively. The correction was stable in all eyes 3 years after surgery. No potentially sight-threatening complications occurred.

CONCLUSION

The 3-year follow-up showed the iris-fixated toric pIOL was effective in correcting high ametropia and astigmatism.

The Influence of Incision-Induced Astigmatism and Axial Lens Position on the Correction of Myopic Astigmatism with the Artisan Toric Phakic Intraocular Lens

PURPOSE

To evaluate postoperative astigmatism with regard to incision-induced astigmatism and deviation in axial alignment with the use of preoperative limbal marking with the Javal keratometer (Haag Streit, Bern, Switzerland) in eyes implanted with the Artisan toric phakic intraocular lens (IOL) (Ophtec, Groningen, The Netherlands).

DESIGN

Prospective nonrandomized trial.

PARTICIPANTS

Fifty-four eyes of 33 patients with myopia (mean, -9.67 diopters [D]) and astigmatism (mean, -3.44 D).

INTERVENTION

The enclavation site was marked on the limbus using the Javal keratometer. The Artisan toric phakic IOL was implanted according to the axis marked on the limbus. Follow-up was a minimum of 6 months.

MAIN OUTCOME MEASURES

Safety index, efficacy index, predictability, safety, and vector analysis of total refractive correction were determined. The effects of axis misalignment and incision-induced astigmatism on the final refractive error were evaluated.

RESULTS

At 6 months after surgery, the safety index was 1.29+/-0.29 and the efficacy index was 1.04+/-0.35. Mean spherical equivalent subjective refraction reduced from -11.39+/-4.86 D before surgery to -0.38+/-0.57 D at 6 months. Sixty-seven percent of eyes were within 0.50 D of attempted refraction and 89% were within 1.00 D. Mean preoperative cylinder was 2.92+/-1.60 D at 91.4 degrees . At 6 months, the mean cylinder was 0.28+/-0.54 D at 174.3 degrees . No eyes lost 2 or more lines of best-corrected visual acuity at 6 months. Eighty-three percent of eyes achieved uncorrected visual acuity of 20/40 and 28% achieved 20/20. Vector analysis of total surgically induced astigmatism revealed a mean cylindrical change of 3.21+/-1.71 D. Average axis misalignment was 0.37+/-5.34 degrees . The mean incision-induced astigmatism was 0.74+/-0.61 D at 0.2 degrees .

CONCLUSIONS

Implantation of the myopic toric IOL leads to safe, efficacious, and predictable results. The level of unpredictability caused by minor axis IOL misalignment has minimal effects on the residual refractive error. The procedure of axis alignment with the Javal keratometer seems to be an accurate method of marking the eye for toric IOL implantation. Incision-induced astigmatism can result in an overcorrection of the cylinder. A systematic undercorrection of -0.50 D for attempted cylindrical outcome could result in an achieved correction closer to emmetropia.

Changes in higher-order aberrations after implantation of a foldable iris-claw lens in myopic phakic eyes

PURPOSE

To evaluate the change in higher-order aberrations (HOAs) after implantation of a foldable iris-claw phakic intraocular lens (pIOL) in myopic eyes.

SETTING

Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany.

METHODS

This prospective nonrandomized comparative self-controlled trial included 41 eyes that had implantation of a foldable iris-claw pIOL between July 2003 and November 2004. All patient data for HOAs (Zernike coefficient) were measured and calculated using the same pupil size preoperatively and postoperatively, and the root-mean-square (RMS) wavefront error was calculated. Examinations were performed preoperatively as well as 1 week and 3, 6, and 12 months after pIOL implantation.

RESULTS

The mean preoperative sphere was -8.12 diopters (D) +/- 2.01 (SD) (range -12.25 to -3.75 D) and the mean preoperative cylinder, -0.90 +/- 0.62 D (range -2.50 to 0.00 D). The Z3(1) and Z(3)(-1) coefficients decreased after implantation of the foldable iris-claw pIOL, but the decrease was not statistically significant (P = .078 and P = .45, respectively). There was a statistically significant reduction in Z4(0) in the first postoperative week (P = .038), but the decrease was not significant thereafter. There was a statistically significant reduction in total RMS wavefront error from preoperatively to all values postoperatively (P = .008).

CONCLUSION

Over a 12-month follow-up, 3rd-order and 4th-order HOAs did not increase after foldable iris-claw pIOL implantation in myopic eyes.

Evaluation of Pupil Dynamics After Implantation of Artisan Phakic Intraocular Lenses

PURPOSE

To compare pre- and postoperative horizontal and vertical pupil diameters after horizontal Artisan phakic intraocular lens (PIOL) (Ophtec BV, Groningen, The Netherlands) implantation for correction of myopia.

METHODS

The pre- and postoperative scotopic pupil diameters measured by the Colvard pupillometer (Oasis Medical, Glendora, Calif) were compared in 71 eyes after Artisan PIOL implantation (Artisan Colvard group). Analysis of pupil shape (vertical vs horizontal diameter, V/H ratio) after horizontal Artisan PIOL implantation was performed with the Procyon pupillometer (Procyon Instruments Ltd, London, United Kingdom) in 121 eyes (Artisan Procyon group) under scotopic, mesopic-low, and mesopic-high conditions and compared to an age- and refraction-matched control group of 121 eyes of refractive surgery candidates (Procyon control group).

RESULTS

After horizontal Artisan PIOL implantation, the mean horizontal pupil diameter decreased from 6.231 +/- 0.70 mm preoperatively to 5.34 +/- 0.68 mm postoperatively in the Artisan Colvard group (P < .01). The mean horizontal scotopic diameter was 5.60 +/- 0.66 mm, the mesopic-low diameter was 4.94 +/- 0.71 mm, and the mesopic-high diameter was 3.98 +/- 0.54 mm for the Artisan Procyon group. The mean horizontal scotopic diameter was 6.29 +/- 0.91 mm, the mesopic-low diameter was 5.40 +/- 0.96 mm, and the mesopic-high diameter was 4.16 +/- 0.80 mm in the Procyon control group. A significant increase was noted in V/H ratio under scotopic, mesopic-low, and mesopic-high conditions from 1.02, 1.02, and 1.01, respectively, in the Procyon control group to 1.17, 1.12, and 1.06, respectively, in the Artisan Procyon group (P < .01).

CONCLUSIONS

Horizontal pupil size was significantly decreased after horizontal Artisan PIOL implantation and might be attributed to a mechanical restriction of the iris in the horizontal meridian.

Implantation of Verisyse Phakic Intraocular Lens to Correct Myopic Refractive Error After Penetrating Keratoplasty in Pseudophakic Eyes

PURPOSE

We report 2 cases in which a Verisyse phakic intraocular lens (PIOL) was used to successfully treat high myopia after penetrating keratoplasty (PK) in pseudophakic patients.

METHODS

Case 1 involved a 69-year-old pseudophakic man with a manifest refraction (MR) of -6.50 + 1.75 x 048 and a best spectacle corrected visual acuity (BSCVA) of 20/40 approximately 16 months after PK in the right eye. Case 2 was a 78-year-old pseudophakic man who had an MR of -9.00 + 5.75 x 132 with a BSCVA of 20/100 approximately 24 months after PK in the left eye.

RESULTS

In case 1, 10 months after Verisyse PIOL implantation, the MR was pl +2.00 x 135 with a BSCVA of 20/30. Endothelial cell density (ECD) in this patient decreased from 1926.1 to 815.3 cells/mm over 17 months. In case 2, 24 months after Verisyse PIOL implantation, the MR was -3.25 + 3.50 x 105 with a BSCVA of 20/60. ECD in this patient decreased from 2108.4 to 753.8 cells/mm in 30 months.

CONCLUSION

The Verisyse PIOL may provide an alternative method to correct high myopia for anisometropia in pseudophakic patients after PK. In this report, PIOL implantation was associated with a decrease in ECD. Further studies are required to determine the long-term effects and ultimate safety of PIOL placement on the integrity of the cornea endothelium after corneal transplant in pseudophakic patients.

Short-term Follow-up after Implantation of a Foldable Iris-Fixated Intraocular Lens in Phakic Eyes

OBJECTIVE

To evaluate efficiency, predictability, stability, complications, and patient satisfaction after implantation of a foldable iris-fixated phakic intraocular lens (PIOL) for the correction of myopia.

DESIGN

Prospective, nonrandomized, comparative (self-controlled) trial.

PARTICIPANTS

Forty-one eyes of 22 myopic patients aged 18 to 56 years (mean, 36 years) with average sphere of -8.2+/-2.01 diopters (D; range, -12.25 to -3.75 D) and average preoperative cylinder of -0.90+/-0.62 D (range, -2.50 to 0.00 D) were enrolled in this prospective study.

METHODS

All eyes underwent implantation of a foldable iris-fixated PIOL with an optical zone of 6.0 mm. The follow-up was 6 months in all cases. Phakic intraocular lenses were available in powers ranging from -2.0 D to -12.0 D.

MAIN OUTCOME MEASURES

The main parameters assessed were best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity, refraction, endothelial cell count, intraocular pressure, slit-lamp biomicroscopy, and indirect ophthalmoscopy.

RESULTS

At 6 months' follow-up, no eyes experienced a loss in BSCVA and 78% gained 1 or more lines of their preoperative BSCVA. Uncorrected visual acuity was significantly improved, with 82% of eyes reaching 20/25 or better. There was a significant reduction in spherical errors in all patients after surgery. Ninety-one percent of eyes were within +/-0.50 D of target refraction. A slight loss of endothelial cells (2.3 %) was observed 6 months after surgery. There were no intraoperative complications. In the postoperative follow-up, however, pigment precipitates were noted in 5 eyes of 4 patients.

CONCLUSIONS

At short-term follow-up, the implantation of the foldable iris-fixated PIOL proved to be effective and predictable for the correction of myopia in phakic eyes. However, longer follow-up with larger numbers of patients is necessary to evaluate long-term complications.

Phakic Intraocular Lenses

An analytical review of the data available in the field of phakic intraocular lens implantation was conducted. Particular attention was paid to the more critical issues of intraocular lens sizing and safety guidelines. A comprehensive, competitive analysis of different implantation sites, intraocular lens model designs, and safety guidelines has been included. Specialized biometry techniques, such as very high frequency ultrasound and Scheimpflug imaging, have been reviewed, and a critical review of commercial claims regarding intraocular lens technologies has been included. Clinical studies of phakic intraocular lenses demonstrate increasing promise for the correction of refractive errors not amenable to mainstream excimer laser refractive surgery. The main issues currently revolve around adequate lens design (VHF ultrasound study suggests that custom-design and sizing may be the most effective and safest approach for every phakic IOL model), because these devices will be required to remain physiologically inert and anatomically compatible with internal ocular structures and relations for several decades. The possibility of safe removing or exchanging the IOL should remain a feasible option over time. It is of utmost importance that we continue to critically evaluate current encouraging short-term outcomes, which are being extrapolated to the longer term by ongoing high resolution imaging and monitoring of the anatomical and functional relations of implanted phakic IOLs.

Intraokularlinsen zur Korrektur von Refraktionsfehlern

In this overview, the current status of intraocular lens surgery to correct refractive error is reviewed. The interventions are divided into additive surgery with intraocular lens implantation without extraction of the crystalline lens (phakic intraocular lens, PIOL) or removal of the crystalline lens with implantation of an IOL (refractive lens exchange, RLE). Phakic IOLs are constructed as angle-supported or iris-fixated anterior chamber lenses and posterior chamber lenses which are fixated in the ciliary sulcus. The implantation of phakic IOLs has been demonstrated to be an effective, safe, predictable and stable procedure to correct higher refractive errors. Complications are rare and differ for the three types of PIOL; for posterior chamber lenses these are mainly cataract formation and pigment dispersion. RLE is preferable in cases of high ametropia in which the natural lens has lost its accommodative effect. The main complications for myopic RLA include retinal detachment, while hyperopic refractive lens exchange may be associated with surgical problems in the narrower anterior eye segment.

Intraokularlinsen zur Korrektur von Refraktionsfehlern

In this overview, the current status of intraocular lens surgery to correct refractive error is reviewed. The interventions are divided into additive surgery with intraocular lens implantation without extraction of the crystalline lens (phakic intraocular lens, PIOL) or the removal of the crystalline lens with implantation of an IOL (refractive lens exchange, RLE). Phakic IOLs are constructed as angle-supported or iris-fixated anterior chamber lenses and posterior chamber lenses that are fixated in the ciliary sulcus. The implantation of phakic IOLs has been demonstrated to be an effective, safe, predictable and stable procedure to correct higher refractive errors. Complications are rare and differ for the three types of PIOL; for anterior chamber lenses these are mainly pupil ovalization and endothelial cell loss.

Implantation of an Artisan phakic intraocular lens for the correction of high myopia after penetrating keratoplasty

We report 2 cases in which an Artisan phakic intraocular lens (IOL) (Ophtec) was used to successfully treat high myopia after penetrating keratoplasty (PKP). The first case was a 43-year-old man who had a manifest refraction of -13.75 +3.00 x 50 with a best corrected visual acuity (BCVA) of 20/40(-2) after PKP in the left eye. Approximately 9 months after implantation of the Artisan IOL, the manifest refraction was -2.00 +2.50 x 60 with a BCVA of 20/30(+2). The second case was a 31-year-old man who had a manifest refraction of -10.75 +2.25 x 122 and a BCVA of 20/40 after corneal transplantation in the right eye. Ten months after implantation of the Artisan IOL, the manifest refraction was -2.75 +4.75 x 80 with a BCVA of 20/40. Endothelial cell density did not change significantly in either patient after surgery. The Artisan phakic IOL may provide an alternative method to correct high myopia after PKP.

Implantation of a toric phakic intraocular lens to correct high corneal astigmatism in a patient with bilateral marginal corneal degeneration

We present a patient with marginal corneal degeneration and corneal astigmatism of more than 10.0 diopters (D). A toric phakic intraocular lens (IOL) of 7.0 D cylindrical power was implanted in both eyes to correct the high astigmatism. An uncorrected visual acuity of 20/40 was achieved in both eyes, and the best corrected visual acuity improved by 4 Snellen lines to 20/20 in both eyes. Refraction and visual acuity remained stable at 1.5 years postoperatively. Implantation of a toric phakic IOL can be an option to correct high corneal astigmatism even when the full corneal astigmatism cannot be treated.

Initial results of endothelial cell counts after Artisan Lens for Phakic Eyes

PURPOSE

To evaluate the endothelial cell count change in eyes implanted with the iris-claw phakic Artisan lens for treatment of moderate to high myopia.

DESIGN

Prospective, multicenter clinical trial.

PARTICIPANTS

The first 765 eyes enrolled at 25 North American sites in the United States Food and Drug Administration Ophtec clinical trial of the myopic Artisan IOL. Outcome analyses of endothelial cell count measurements were based on those obtained before surgery and at 6, 12, and 24 months after surgery performed between October 1998 and December 2001.

SETTING

Multiple private and university practices.

METHODS

Percentage change in endothelial cell count from baseline to 6, 12, and 24 months were analyzed using specular microscopy. Upper limit of detecting endothelial cell density change was estimated using 3 repeated counts at preoperative and postoperative time frames.

MAIN OUTCOME MEASURES

Percentage change in endothelial cell loss.

RESULTS

The mean preoperative endothelial cell count was 2631+/-442 cells/mm(2). Percentage change from baseline at 6, 12, and 24 months was -0.09%+/-16.39%, -0.87%+/-16.35%, and -0.78%+/-17.41%. No statistically significative postoperative endothelial cell loss was found. The endothelial cell loss rate was higher among patients who wore spectacles before surgery and was correlated negatively with preoperative endothelial cell density (P<0.001). No relationships were noted between endothelial cell loss and either patient age or implant power. A 4.1% repeatability of measurements was found based on the average of 3 repeated counts, whereas single cell count estimates were associated with a 23% accuracy in detecting endothelial cell density change. In a worst-case scenario, adjusting for measurement accuracy, 9% of all eyes were at higher risk of a 10% loss of cell density at 12 months after surgery, although eyes at higher risk were found to have high preoperative endothelial cell counts (P<0.0001).

CONCLUSIONS

The Artisan iris-claw phakic intraocular lens did not result in significant loss of endothelial cell density up to 2 years after implantation of the myopic Artisan phakic lens.

Refractive Lens Exchange Versus Iris-claw Artisan Phakic Intraocular Lens for Hyperopia

PURPOSE

To study a paired-match comparison between refractive lens exchange with pseudophakic IOL implant (RLE) and Artisan phakic IOL for high hyperopia.

METHODS

Nineteen eyes (12 patients, 20 to 41 years old) with an Artisan phakic IOL (Model 203: 1.00-D increment) for hyperopia from +2.75 to +9.25 D were matched to 19 eyes (15 patients, 26 to 46 yr) with hyperopia from +2.75 to +7.50 D, who had refractive lens exchange (pseudophakic IOL implantation; lenses: 0.50-D increment). Average paired-match difference was 1.13 D and 7.7 years of age.

RESULTS

At 1 month after surgery, 84% of refractive lens exchange/pseudophakic IOL eyes and 94% of Artisan phakic IOL eyes had a spherical equivalent refraction within +/- 1.00 D of emmetropia; 58% and 68% of eyes, respectively, were within +/- 0.50 D (P = .97). No eye lost lines of best spectacle-corrected visual acuity (BSCVA) and no significant changes in BSCVA were found in any eye at 1 month after surgery (P = .17). The percentage of eyes with uncorrected visual acuity (UCVA) of 20/40 or better improved from 79% to 89% of eyes at 1 to 2 months after phakic IOL; it remained at 89% to 82% of eyes from 1 to 2 months after refractive lens exchange/ pseudophakic IOL. The coefficient of correlation showed statistically better accuracy (intended vs. achieved refraction; P = .035) for the Artisan phakic IOL (R = 0.83) than for refractive lens exchange/ pseudophakic IOL (R = 0.50).

CONCLUSIONS

Spherical equivalent refraction outcome and BSCVA after surgery were similar for both procedures. The Artisan phakic IOL in carefully selected patients provided a better overall outcome for young patients with high hyperopia whose accommodation was preserved, as compared to refractive lens exchange.

Three-year follow-up of the Artisan phakic intraocular lens for hypermetropia

PURPOSE

We report the postoperative results of the Artisan Hyperopia phakic intraocular lens (IOL; model 203W; Ophtec, Groningen, The Netherlands).

DESIGN

Prospective, nonrandomized trial.

PARTICIPANTS

Twenty-six eyes of 13 self-selected patients with refractive error ranging from +3.00 to +11.00 diopters (D).

INTERVENTION

Patients with hypermetropia were implanted with the Artisan Hyperopia phakic IOL. Mean follow-up was 22.4 months (range, 3-36 months).

MAIN OUTCOME MEASURES

Predictability, stability, efficacy, loss of best spectacle-corrected visual acuity, and complications.

RESULTS

At six months, 90.9% (20 of 22 eyes) were +/-1.00 D of intended correction and 81.8% (18 eyes) were +/-1.00 D of emmetropia. The mean spherical equivalent was stable within 0.25 D during the entire 3-year follow-up period. Twenty-four eyes (92.3%) had a postoperative best spectacle-corrected visual acuity of 0.50 or better at all of their individual follow-up examinations. No patient lost 2 or more lines after the procedure. There was a significant negative correlation between anterior chamber depth and endothelial cell loss. Two patients experienced posterior synechiae with pigment deposits in both eyes. One of these patients had convex irides and underwent implant removal within 2 years with a consequent clear lens extraction and posterior chamber lens implantation.

CONCLUSIONS

Implantation of the Artisan Hyperopic lens leads to accurate and stable refractive results with no significant loss of vision. More attention should be paid to convex irides and shallow anterior chambers during the preoperative screening to avoid unnecessary complications.

Anterior chamber iris-fixated phakic intraocular lens for anisometropic amblyopia

We report a child who had implantation of an iris-fixated Artisan phakic intraocular lens (IOL) to correct high unilateral myopia to support the therapy of anisometropic amblyopia. After IOL implantation, the patient continued occlusion therapy to further treat the amblyopic eye. One year postoperatively, the best corrected visual acuity in the amblyopic eye was 1.00 and binocular stereovision had developed. The visual acuity remained stable through 3 years of follow-up. There were no complications, although postoperative endothelial cell loss was significant.

Toric phakic intraocular lens: European multicenter study

OBJECTIVE

To evaluate safety, efficacy, predictability, stability, complications, and patient satisfaction after implantation of Artisan toric phakic intraocular lenses (TPIOLs) for the correction of myopia or hyperopia with astigmatism.

DESIGN

Prospective, nonrandomized, comparative (self-controlled) multicenter trial.

PARTICIPANTS

Seventy eyes of 53 patients (mean, 35 years; range, 22-59 years) with preoperative spherical equivalent between +6.50 and -21.25 diopters (D) and cylinder between 1.50 and 7.25 D.

METHODS

Seventy eyes underwent implantation of a TPIOL with an optical zone of 5.0 mm (Artisan, Ophtec, Groningen, The Netherlands). The dioptric power of the intraocular lens was calculated by considering refraction, keratometry, and anterior chamber depth. The follow-up was 6 months in all cases. Lenses were available in powers ranging from +12.0 D to -23.5 D (spherical equivalent) in 0.5-D increments, with additional cylinder from 1.0 D to 7.0 D, also in 0.5-D increments.

MAIN OUTCOME MEASURES

The main parameters assessed were best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), refraction, endothelial cell count (ECC), intraocular pressure, slit-lamp biomicroscopy, indirect ophthalmoscopy, subjective complaints, and patient satisfaction.

RESULTS

Eyes were divided into group A, myopia (n = 48), with an average preoperative spherical equivalent of -8.90 +/- 4.52 D, and group B, hyperopia (n = 22), with an average preoperative spherical equivalent of +3.25 +/- 1.98 D. No eyes in either group experienced a loss in BSCVA, and 46 eyes gained 1 or more lines of their preoperative BSCVA. In 62 eyes (88.6%), UCVA was 20/40 or better. There was a significant reduction in spherical errors and astigmatism in all cases after surgery. All eyes of both groups were within +/-1.00 D of target refraction, and 51 eyes (72.9%) were within +/-0.50 D of target refraction. There was a 4.5% mean total loss of ECC during the first 6 months. No serious complications were observed. Overall patient satisfaction was very high.

CONCLUSIONS

Six-month clinical trial results demonstrate that implantation of the Artisan TPIOL safely, predictably, and effectively reduced or eliminated high ametropia and astigmatism with one procedure. The refractive effect was stable at 6 months after surgery.