Outcome after treatment of ametropia with implantable contact lenses

Modulation transfer function of intraocular collamer lens with a central artificial hole

BACKGROUND

A modified implantable collamer lens (ICL) with a central hole (diameter 0.36 mm), "Hole-ICL", was created to improve aqueous humour circulation. The aim of this study is to investigate the effects of ICL power and the relationship between pupil size and modulation-transfer functions (MTFs) in a Hole-ICL in vitro.

METHODS

The ICL and intraocular lens (IOL) studied were the Collamer ICL (Model ICM, STAAR Surginal) and the monofocal IOL AF-1 (VA-60BBR, HOYA). The ICLs' powers were -20.0 diopters (D), -10.0 D, -5.0 D, +3.0 D, and +10.0 D. A modified ICL with a central hole (diameter 0.36 mm), "Hole-ICL", was created. The monofocal IOL, which was used as an artificial crystalline lens, was +30.0 D in power, and it was 13.0 mm in length with an optic diameter of 6.0 mm. The line-spread function (LSF) was recorded with the OPAL Vector System (Image Science Ltd.), and a model eye (Menicon Co.) was used that consisted of a wet cell. A conventional ICL or Hole-ICL was placed in the posterior chamber of the model eye. The MTF was calculated from the LSF using fast Fourier transform techniques. Furthermore, we investigated the relationship between pupil size and the MTF of the ICL for -5.0 D. The sizes of the effective aperture were 2.0, 3.0, 4.0, and 5.0 mm.

RESULTS

The in-focus contrasts of the conventional ICL at 100 cyc/mm for a 3.0-mm effective aperture were 37%, 40%, 39%, 38%, and 39% for -20.0 D, -10.0 D, -5.0 D, +3.0 D, and +10.0 D respectively. The in-focus contrasts of the Hole-ICL at 100 cyc/mm for a 3.0-mm effective aperture were 37%, 40%, 39%, 38%, and 38% for -20.0 D, -10.0 D, -5.0 D, +3.0 D, and +10.0 D respectively. The results for a 2.0-mm effective diameter showed that the in-focus MTF in the Hole-ICL was lower than in the conventional ICL, although the difference was small.

CONCLUSION

These results suggest that differences in MTF between the Hole-ICL and the conventional ICL for various ICL powers and effective pupil diameters were small and clinically negligible.

Clinical outcomes of posterior chamber toric phakic intraocular lens implantation for the correction of high myopic astigmatism in eyes with keratoconus: 6-month follow-up

BACKGROUND

To assess the early clinical outcomes of toric implantable collamer lenses (toric ICL™, STAAR Surgical) for the correction of high myopic astigmatism with keratoconus.

METHODS

This study evaluated 27 eyes of 14 patients with spherical equivalents of -10.11 ± 2.46 D (mean ± standard deviation) and astigmatism of -3.03 ± 1.58 D who underwent toric ICL implantation for mild keratoconus. Before, and 1, 3 and 6 months after surgery, we assessed the safety, efficacy, predictability, stability, and adverse events of the surgery.

RESULTS

LogMAR uncorrected visual acuity (UCVA) and LogMAR best spectacle-corrected visual acuity (BSCVA) were -0.09 ± 0.16 and -0.15 ± 0.09 respectively, 6 months after surgery. The safety and efficacy indices were 1.12 ± 0.18 and 1.01 ± 0.25. At 6 months, 85% and 96% of the eyes were within ±0.5 and ±1.0 D respectively of the targeted correction. Manifest refraction changes of 0.00 ± 0.35 D occurred from 1 week to 6 months. No vision-threatening complications occurred during the observation period.

CONCLUSIONS

Toric ICL implantation was good in all measures of safety, efficacy, predictability, and stability for the correction of spherical and cylindrical errors in eyes with early keratoconus throughout the 6-month follow-up period, suggesting its viability as a surgical option for the treatment of such eyes.

Long-term follow-up of first-generation posterior chamber phakic intraocular lens

We present a patient who received a first-generation posterior chamber phakic intraocular lens (PC pIOL) (Fyodorov IOL) to correct myopia 18 years previously. After a long lapse in the follow-up, the patient presented with a reduced endothelial cell count. Although the cataractogenic effect of first-generation PC pIOLs is well known, no sign of cataract was present. The patient was totally satisfied even after 18 years. To our knowledge, this is the first report of a long follow-up of a patient implanted with a first-generation PC pIOL.

Comparison of clear lens extraction and collamer lens implantation in high myopia

Aim:

To compare the outcomes of clear lens extraction and collamer lens implantation in high myopia.

Patients and methods:

Myopic patients younger than 40 years old with more than 12 diopters of myopia or who were not fit for laser-assisted in situ keratomileusis were included. Group 1 comprised patients undergoing clear lens extraction and Group 2 patients received the Visian implantable collamer lens. Outcome and complications were evaluated.

Results:

Postoperative best corrected visual acuity was −0.61 ± 0.18 in Group 1 and 0.79 ± 0.16 in Group 2. In Group 1, 71.4% achieved a postoperative uncorrected visual acuity better than the preoperative best corrected visual acuity, while only 51.8% patients achieved this in Group 2. Intraocular pressure decreased by 12.55% in Group 1, and increased by 15.11% in Group 2. Corneal endothelial cell density decreased by 4.47% in Group 1 and decreased by 5.67% in Group 2. Posterior capsule opacification occurred in Group 1. In Group 2, lens opacification occurred in 11.11%, significant pigment dispersion in 3.7%, and pupillary block glaucoma in 3.7%.

Conclusion:

Clear lens extraction presents less of a financial load up front, and less likelihood of the need for a secondary intervention in the future. Clear lens extraction is a more viable solution in developing countries with limited financial resources.

Comparison of the toric implantable collamer lens and bioptics for myopic astigmatism

PURPOSE

To compare results between toric implantable collamer lens (TICL) implantation and bioptics (ICL and excimer laser ablation) for the correction of myopic astigmatism.

METHODS

A retrospective evaluation was performed in 29 eyes (20 patients) with TICL implantation and 26 eyes (17 patients) treated with bioptics. For eyes treated with bioptics, corneal ablation was performed at 1.5 to 5 months (mean 2.56 months) after ICL implantation by laser epithelial keratomileusis in 17 eyes, LASIK in 8 eyes, and photorefractive keratectomy in 1 eye. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity, refraction, adverse events, safety, and efficacy were assessed preoperatively and 1, 6, and 12 months postoperatively.

RESULTS

At 1 month postoperatively, UDVA in the TICL group was significantly higher than in the bioptics group (P=.02). However, the difference in UDVA at 12 months was not significant. At 12 months, mean spherical equivalent refraction was 0.33±0.21 diopters (D) in the TICL group and 0.29±0.41 D in the bioptics group (P=.07). Mean astigmatic error was higher in the TICL group (-0.42±0.32 D) than in the bioptics group (-0.32±0.38 D) (P=.10). In the bioptics group, the mean refractive cylinder at 12 months decreased from that reported at 6 months because of retreatment performed in two eyes. Safety and efficacy were not statistically different between groups. One eye with a TICL was treated to correct TICL decentration. Two crystalline lens opacities were observed after bioptics.

CONCLUSIONS

This study demonstrates that TICL implantation provides reliable visual outcomes similar to bioptics. The advantages of TICL implantation are a more stable visual outcome and the elimination of laser treatments and their inherent risks.

Long-term changes in posterior chamber phakic intraocular collamer lens vaulting in myopic patients

OBJECTIVE

Evaluation of central and midperipheral vaulting of the posterior chamber phakic intraocular Collamer lens (ICL; Staar Surgical Inc., Monrovia, CA) in eyes with moderate to high myopia.

DESIGN

Retrospective analysis of prospectively collected data.

PARTICIPANTS

Eighty-four eyes treated with the latest ICL (V4 model) and 27 eyes treated with early ICL models were examined.

METHODS

After standardized ICL implantation, patients underwent complete ophthalmologic examinations before surgery and at 1 week, 1 month, 3 months, 6 months, and at yearly intervals thereafter. Central vaulting was measured using the Jaeger device (Haag-Streit, Bern, Switzerland). From 2006 onward, vaulting was measured additionally by optical coherence tomography (Visante OCT; Carl Zeiss Meditec, Jena, Germany). Using the Visante OCT, the crystalline lens rise and the midperipheral vaulting of the ICL were assessed.

MAIN OUTCOME MEASURES

Central vaulting after ICL implantation.

RESULTS

The mean duration of follow-up was 74.1+/-23.1 months and 96.3+/-50.2 months in eyes treated with V4 and early models, respectively. Postoperative central vaulting was 466+/-218 microm (range, 30-900 microm) in eyes treated with the V4 models and 321+/-200 microm (range, 150-900 microm) in those treated with early ICL models. From the 6-month follow-up onward, a continuous and nearly linear reduction of central vaulting was observed. At the 10-year follow-up, the mean central vaulting was reduced to 184+/-159 microm (range, 6-500 microm) and 138+/-218 microm (range, 0-820 microm) in eyes treated with V4 or early models, respectively. Eyes with total vaulting had a mean central vaulting of 407+/-202 microm (range, 180-730 microm), whereas those with midperipheral contact had a significantly lower central vaulting of 105+/-87 microm (range, 0-200 microm).

CONCLUSIONS

This study revealed consistent reduction of central vaulting over a 10-year period and provides further evidence that insufficient vaulting of the ICL is responsible for the development of anterior subcapsular cataract. A minimum central vaulting of 230 microm seems to be necessary to ensure total vaulting of the ICL. If an ICL is chosen for the correction of myopia, targeting for the greatest possible postoperative central vaulting is advised to achieve safe and complete vaulting for several years.

Toric implantable collamer lens for patients with moderate to severe myopic astigmatism: 12-month follow-up

PURPOSE

To report on the 12-month follow-up of 77 eyes with moderate to high myopic astigmatism implanted with toric implantable collamer lenses (ICLs).

METHODS

Retrospective case-note review of 77 eyes from 42 patients undergoing toric ICL placement by one surgeon. Preoperative mean spherical equivalent -2.50 dioptres (D) to -15.00 D myopia and 1.00 D to 7.00 D astigmatism.

RESULTS

At 12 months, mean manifest refractive cylinder (MRC) decreased 81% from 2.38 D to 0.44 D. MRC within 1.00 D occurred in 99% (76/77) of eyes, whereas 86% (66/77) had MRC within 0.75 D. 99% (76/77) had postoperative best-corrected visual acuity (BCVA) better than or equal to preoperative values, whereas 78% (60/77) gained up to one line BCVA and 1% (1/77) lost one line BCVA. Uncorrected binocular vision of 6/6 or better occurred in 90% (38/42) of patients compared with binocular BCVA of 6/6 or better in 67% (28/42) preoperatively. One ICL was replaced due to low vaulting. Two eyes with astigmatism of 3.25 D and 3.50 D received subsequent laser in situ keratomileusis (LASIK) to reduce residual small refractive errors. Indications for ICL were: myopia too high for LASIK (73%), cornea too thin for LASIK (44%) and contact lens intolerance (33%). Night halos were reported in 10% (8/77) of eyes at 12 months. One ICL was removed due to unrecognized preoperative glaucoma. There were no cases of cataract formation, or endophthalmitis.

CONCLUSION

This study is the largest reported series of toric ICL implantation in New Zealand. It supports the safety, efficacy and predictability of toric ICLs to treat myopic astigmatism.

Culture-positive endophthalmitis after implantation of intraocular Collamer lens

We report a case of culture-positive bacterial endophthalmitis following implantation of a Staar intraocular Collamer lens (ICL). The patient presented 4 days after uneventful sutureless surgery with decreased visual acuity, redness, and photosensitivity. Inflammation increased over the next 24 hours, which prompted a tap for culture and intravitreal injection of antibiotic agents. Vitreous culture was positive for coagulase-negative Staphylococcus epidermidis. One year postoperatively, the uncorrected distance visual acuity was 20/20; persistent anterior vitreous opacities were the only observable sequelae. Bacterial endophthalmitis is a potential complication of ICL implantation. It can be successfully diagnosed and treated if a high degree of suspicion is maintained and if appropriate diagnostic and treatment modalities are used.

Visual performance after implantable collamer lens implantation and wavefront-guided laser in situ keratomileusis for high myopia

PURPOSE

To compare postoperative visual function after implantable collamer lens (ICL; STAAR Surgical, Nidau, Switzerland) implantation and after wavefront-guided laser in situ keratomileusis (WFG-LASIK) in eyes with high myopia.

DESIGN

Retrospective, observational case study.

METHODS

We investigated 46 eyes of 33 patients undergoing ICL implantation and 47 eyes of 29 patients undergoing WFG-LASIK (Technolas217z; Bausch & Lomb, Rochester, New York, USA) for the correction of high myopia (manifest spherical equivalent < or = -6 diopters). Ocular higher-order aberrations (HOA) and contrast sensitivity (CS) function were measured by Hartmann-Shack aberrometry (KR-9000; Topcon, Tokyo, Japan) and a CS unit (VCTS-6500; Vistech Consultants Inc, Dayton, Ohio, USA) before and 3 months after surgery, respectively. From the CS, the area under the log CS function (AULCSF) was calculated.

RESULTS

For a 4-mm pupil, the changes in ocular coma-like aberrations, spherical-like aberrations, and total HOAs after ICL implantation were significantly less than those after WFG-LASIK (P < .001, Mann-Whitney U test). The postoperative AULCSF was significantly increased after ICL implantation (P < .001), whereas after WFG-LASIK, it was significantly decreased (P < .001).

CONCLUSIONS

ICL implantation induces significantly fewer ocular HOAs than WFG-LASIK. Moreover, CS was improved significantly after ICL implantation, but deteriorated after WFG-LASIK in eyes with high myopia. Thus, in the correction of high myopia, ICL implantation seems to be superior in visual performance to WFG-LASIK, suggesting that it may be a better surgical option for the treatment of such eyes.

Factors affecting vaulting after implantable collamer lens implantation

PURPOSE

To evaluate the vaulting of the STAAR Implantable Collamer Lens (ICL) over the crystalline lens after implantation.

METHODS

One hundred twenty-three eyes of 68 patients with myopic refractive errors of -3.25 to -22.75 diopters undergoing ICL implantation were examined retrospectively. The magnitude of the central vaulting of the ICL was assessed quantitatively using slit-lamp microscopy at 3 months after surgery. Multiple regression analysis was used to assess the factors affecting the amount of vaulting.

RESULTS

The mean central vaulting 3 months after surgery was 603.6 +/- 259.6 microm. Explanatory variables relevant to the vaulting were, in order of influence, the horizontal white-to-white distance (partial regression coefficient B = 0.268, P = .0002) and patient age (B = -0.007, P = .011).

CONCLUSIONS

Although the majority of the variance remains unexplained, younger patients' eyes and eyes with greater white-to-white distances are more predisposed to have higher ICL vaulting over the crystalline lens.

Comparison of Collamer toric implantable [corrected] contact lens implantation and wavefront-guided laser in situ keratomileusis for high myopic astigmatism

PURPOSE

To compare the postoperative visual outcomes after implantation of a Collamer toric implantable contact lens (ICL) and after wavefront-guided laser in situ keratomileusis in high myopic astigmatism.

SETTING

Department of Ophthalmology, Kitasato University, Kanagawa, Japan.

METHODS

This study comprised 30 eyes (18 patients) having toric ICL implantation and 24 eyes (17 patients) having wavefront-guided LASIK (Technolas 217z) to correct high myopic astigmatism (manifest spherical equivalent [SE] <or=-6.0 diopters [D]; manifest refractive cylinder >or=1.0 D). The safety, efficacy, predictability, stability, and adverse events were assessed preoperatively and 1 week and 1, 3, and 6 months postoperatively.

RESULTS

At 6 months, the mean safety index was 1.28+/-0.25 (SD) in the ICL group and 1.01+/-0.16 in the LASIK group and the mean efficacy index, 0.87+/-0.15 and 0.83+/-0.23, respectively. All eyes in the ICL group and 71% of eyes in the LASIK group were within +/-1.00 D of the targeted SE correction at 6 months. The mean change in manifest refraction from 1 week to 6 months was -0.04+/-0.24 D in the ICL group and -0.60+/-0.49 D in the LASIK group. There were no significant complications in the ICL group; 2 eyes (8.3%) in the LASIK group required enhancement ablations.

CONCLUSION

Toric ICL implantation was better than wavefront-guided LASIK in eyes with high myopic astigmatism in almost all measures of safety, efficacy, predictability, and stability, suggesting that toric ICL implantation may become a viable surgical option to treat high myopic astigmatism.

Time course of accommodation after implantable collamer lens implantation

PURPOSE

To assess the time course of accommodative function after Implantable Collamer Lens (ICL) implantation and to investigate the relationship between patient age and accommodation in ICL-implanted eyes.

DESIGN

Prospective, nonrandomized clinical trial.

METHODS

We prospectively examined 69 eyes of 40 consecutive patients with myopic refractive errors of -3.25 to -22.75 diopters (D) who were undergoing ICL implantation. We assessed the amplitude of accommodation using an accommodometer before and one, three, six, and 12 months after surgery. We also investigated its relationship with patient age.

RESULTS

The accommodation was 6.36 +/- 3.94 D (mean +/- standard deviation) before surgery and 4.89 +/- 2.72 D, 4.98 +/- 2.67 D, 5.16 +/- 2.72 D, and 5.72 +/- 2.85 D at one, three, six, and 12 months after surgery, respectively. The variance of data was statistically significant (P = .02, repeated-measures analysis of variance). Multiple comparisons demonstrated significant differences between measurements made before surgery and at one month after (P = .004, Fisher least significant difference test), before surgery and at three months after (P = .007), and before surgery and at six months after (P = .01). There was a significant correlation between patient age and accommodation before (Pearson correlation coefficient, r = -0.665; P < .001) and one year after (r = -0.803; P < .001) ICL implantation.

CONCLUSIONS

Accommodation was impaired transiently in the early postoperative periods, and then recovered gradually over time, indicating that transient dysfunction of the ciliary muscles by ICL fixation may occur after ICL implantation even if the crystalline lens remained intact. As patients aged, the amplitude of accommodation became significantly smaller not only in normal eyes but also in ICL-implanted eyes.

Optical Coherence Tomography of the Anterior Segment in Eyes with Phakic Refractive Lenses

PURPOSE

To evaluate the dynamics of the phakic refractive lens (PRL) in myopic and hyperopic eyes in the nonaccommodated state and during subjective accommodation with Visante optical coherence tomography (OCT).

DESIGN

Cross-sectional study.

PARTICIPANTS

Forty-one myopic eyes and 11 hyperopic eyes of 52 patients (mean age, 34 years; range, 24-49) were examined at least 1 year after PRL implantation using Visante OCT. Thirty-one myopic eyes had the PRL model 101 and 10 eyes had the smaller PRL model 100 implanted. The hyperopic model, PRL 200, is available in only one size.

METHODS

Noninvasive high-resolution anterior OCT was used to measure distance changes between the PRL and adjacent intraocular structures in the nonaccommodative state (baseline) and during accommodation.

MAIN OUTCOME MEASURES

Mean distance changes from the anterior lens surface (ALS) to the PRL and from the corneal posterior surface to the ALS and the PRL, and changes in the pupil diameter.

RESULTS

At baseline, the mean distances between the PRL and crystalline lens were 0.38, 0.30, and 0.32 mm for the PRL 101, PRL 100, and PRL 200, respectively. The PRLs were significantly closer to the crystalline lens with increasing patient age. Three PRLs were in contact with the crystalline lens (6%), and there were lens opacities in 2 of these eyes. During accommodation, the ALS of all PRL models showed significant forward movement (P<0.05), whereas the distance between the PRL and crystalline lens decreased significantly with the PRL 101 and PRL 200 (P<0.05). The distance between the PRL 100 and crystalline lens remained unchanged during accommodation.

CONCLUSION

The PRL moved forward during accommodation in all eyes, with the distance preserved between the PRL and the ALS with the PRL 100. The distance decreased with the other 2 models. In 85% of cases, there was no mechanical contact with the ALS during accommodation.

Calculating the power of toric phakic intraocular lenses

BACKGROUND AND PURPOSE

A toric phakic intraocular lens (IOL) implanted in the anterior or posterior chamber of the eye has the potential to correct high or excessive ametropia and astigmatism with high predictability of the postoperative refraction and preservation of phakic accommodation. The calculation of spherical phakic lenses has been described previously, but a formalism for estimating the power of toric phakic lenses has not yet been published. The purpose of this study is to describe a mathematical strategy for calculating toric phakic IOLs.

METHODS

The method presented in this paper is based on vergence transformation in the paraxial Gaussian space. Parameters used for the calculations are the spherocylindrical spectacle refraction before implantation, corneal power (sphere and astigmatism) and (spherocylindrical) target refraction, together with the vertex distance and the predicted position of the phakic IOL. The lens power is determined as the difference in vergences between the spectacle-corrected eye and the uncorrected eye at the reference plane of the predicted lens position. The axes of the preoperative refraction, the target refraction and the corneal astigmatism are at random (not necessarily aligned).

RESULTS

The method was applied to two clinical examples. In example 1 we calculate the power of a phakic lens for the simple case, when the target refraction is plano and the axis of the preoperative refraction is aligned to the axis of the corneal astigmatism. In example 2, the cylindrical axis of the preoperative refraction is not aligned to the corneal astigmatism and the target refraction is spherocylindrical (and the axis of the target refraction is not aligned to the preoperative refractive cylinder or the corneal astigmatism). The calculations for both examples are described step-by-step and illustrated in a table.

CONCLUSIONS

The calculation scheme can be generalized to an unlimited number of crossed cylinders in the optical pathway. Based on paraxial raytracing, the spherical and cylindrical power as well as the orientation of the cylinder are determined from the preoperative refraction (including vertex distance), the corneal power, the intended target refraction (including vertex distance) and the predicted position of the phakic lens implant provided by the lens manufacturer. This calculation scheme can be easily implemented in a simple computer program (i.e. in Microsoft excel or matlab).

Magnification and accommodation with phakic intraocular lenses

BACKGROUND AND PURPOSE

The calculation of phakic lenses (PL) was described by van der Heijde et al. [Klin. Monatsbl. Augenheilkd (1988) Vol. 193, pp. 99-102], but a formalism for estimating relative magnification compared with spectacle correction and accommodation effects are not yet published. The purpose of this study was to describe a mathematical strategy for calculating PL and relative magnification as a function of object vergence (phakic accommodation).

METHODS

Parameters used for the calculations are the spectacle refraction before and after (target refraction) surgery, the vertex distance, corneal refraction, and the predicted position of the phakic intraocular lens. The lens power is determined as the difference in vergences between the spectacle-corrected eye and the uncorrected eye at the reference plane of the predicted lens position. If we simplify the crystalline lens to a single refracting surface located at the principal plane of the crystalline lens, the vergence of the eye with spectacle correction and with PL is determined as a function of object distance [object vergence 0 D (infinity) to 10 D (object at a distance of 10 cm)] to evaluate accommodation effects of the crystalline lens.

RESULTS

The method was applied to two clinical examples. In example 1 we calculated the power of a PL for correction of a 10-D myopia and determined the relative magnification and the vergence at the principal plane of the crystalline lens as a function of object vergence. Magnification gain increases with objects at near from 17% to 26%, whereas the vergence at the principal plane of the crystalline lens changes by 3.04 D less than in the spectacle-corrected eye. In example 2, a 20-D myopia was corrected with a PL. The gain in magnification changed from 33% to 58% with nearer objects. The change in vergence at the principal plane of the crystalline lens with objects at near was much higher with the PL compared with the spectacle correction, which implies that the refractive change necessary for focusing objects at near distance is much higher in the PL correction.

CONCLUSIONS

Even if the predictability of postoperative refraction with PL is comparable or better than in other methods of correcting high or excessive ametropia, the effects of lateral magnification change and accommodation have to be considered to avoid image-size disparities (aniseikonia) and to maintain binocular vision, especially with monocular PL implantation and anisometropia.

Efficacité réfractive et tolérance de l’implant phaque myopique souple à fixation irienne Artiflex® dans la correction chirurgicale de la myopie forte : résultats à deux ans

INTRODUCTION

A new foldable version of an anterior chamber phakic lens designed to surgically correct high myopia was evaluated.

PATIENTS AND METHODS

A prospective study on the efficacy and tolerance of a foldable phakic intraocular iris-supported lens, designed to correct moderately high myopia, is presented in this article. Twenty-five eyes of 25 patients were implanted uneventfully using this lens, newly designed and called the Artiflex lens. This phakic intraocular lens is an upgraded foldable version of the Artisan (or Verisyse) lens. The follow-up was complete (24 months) for all Artiflex-treated eyes and the targeted postoperative refraction was emmetropia. Inclusion criteria were moderately high myopia ranging from -8 to -14 D, unchanged refraction for 2 years, total contact lenses wearing intolerance, refractive cylinder power no greater than 1.5 D, anterior chamber depth greater than 3 mm, and endothelial cell count greater than 2,200 cells/mm2.

RESULTS

The preoperative spherical equivalent was -9.70+/-2.37 D. The spherical equivalent was -1.07+/-0.84 D at 2 years postoperatively. The surgically induced astigmatism was 0.42 D x 67.4-degree axis. The percentage of eyes with an uncorrected visual acuity greater than or equal to 0.5 and 0.8 was 66.6% and 33.3%, respectively. Neither intra- nor postoperative complications were noted during the entire follow-up period. The mean endothelial cell count value was 2267+/-352 at 2 years postoperatively. The objective and subjective quality of vision was acceptable, associated with a high level of patient satisfaction.

DISCUSSION

The refractive results and tolerance of the Artiflex lens are satisfactory and seem to be as good as other phakic intraocular lens outcomes.

CONCLUSION

To correct moderately high myopia, the Artiflex lens seems to provide a suitable refractive efficacy and a quick visual recovery, secondary to a lowering of induced astigmatism. Furthermore, this phakic intraocular lens is associated with satisfactory safety and quality of vision at each milestone of the entire follow-up period.

Visian Collamer Phakic Intraocular Lens in High Myopic Asian Eyes

PURPOSE

To evaluate the safety and efficacy of the Implantable Collamer Lens (Visian), a phakic intraocular lens (PIOL), in the correction of high myopia in Asian eyes.

METHODS

This prospective study comprised 61 eyes in 40 Chinese patients with mean preoperative manifest spherical equivalent refraction of -14.54 +/- 3.61 diopters (D) (range: -7.00 to -24.75 D) who underwent Visian PIOL implantation from May 2002 to December 2004. The anatomical differences between Asian and Caucasian eyes were compared.

RESULTS

Mean follow-up was 13.67 +/- 8.51 months (range: 1 to 32 months). Predictability of the manifest spherical equivalent refraction to within +/- 1.00 D was achieved in 88% of eyes and +/- 0.50 D in 72.5% of eyes. The mean postoperative manifest spherical equivalent refraction was -0.10 +/- 0.74 D, with 97% of eyes maintaining or gaining > or = 1 lines of best spectacle-corrected visual acuity (BSCVA). Two eyes lost 1 line of BSCVA. Retinal detachment developed in 1 eye 15 months after initial surgery. Because of the statistical differences in anterior chamber depth and white-to-white distance between Caucasian and Chinese eyes, the Visian PIOL size was more accurate if the calculation was modified so that 0.5 mm was added to the white-to-white measurement if the anterior chamber depth was < or = 3.0 mm and 1.0 mm to the white-to-white measurement if the anterior chamber depth was >3.0 mm. Initial incorrect sizing using the original nomogram led to the only cataract in our series.

CONCLUSIONS

The implantation of the Visian PIOL for correcting moderate to high myopia in Asian eyes shows similar safety and efficacy to the FDA clinical trial of Caucasian eyes. Proper sizing of the Visian PIOL is important and differs slightly in Asian eyes.

Correction of high myopia with the PRL phakic intraocular lens

PURPOSE

To assess the predictability, efficacy, safety, and complications of the PRL (CIBA Vision) phakic intraocular lens (pIOL) in the correction of high myopia.

SETTING

Clínica Oftalmológica Pasteur, Santiago, Chile.

METHODS

This prospective study comprised 53 eyes of 39 patients who received a PRL pIOL. The spherical equivalent (SE), uncorrected visual acuity (UCVA), efficacy index (postoperative UCVA/preoperative best spectacle-corrected visual acuity [BSCVA]), safety index (BSCVA/preoperative BSCVA), intraocular pressure (IOP), iridocorneal angle, and distance between the crystalline lens and PRL were prospectively assessed during the follow-up period.

RESULTS

The mean patient age was 39 years. The mean power of the implanted pIOL was -12.73 diopters (D) +/- 2.87 (SD) (range -20.00 to -7.00 D), for a preoperative SE of -17.27 +/- 4.58 D (range -31.50 to -8.75 D). The mean preoperative BSCVA was 0.50 +/- 0.70 (logMAR equivalent), and the mean follow-up was 8 +/- 9.4 months. The mean postoperative SE was -0.23 +/- 1.05 D; 71.2% of eyes were within +/-1.00 D. Sixty percent of patients had UCVA of 20/40 or better, and 88.2% of patients had BSCVA of 20/40 or better. Ninety-two percent maintained or gained 1 or more lines of BSCVA; 5.7% lost more than 1 line. There was no significant change in IOP (P = .40), and the mean distance between the crystalline lens and pIOL was 370 microm (ultrasound) and 604 microm (optical coherence tomography). Late complications included 1 case each of retinal detachment and lens subluxation.

CONCLUSIONS

Although PRL implantation in high myopia was predictable and effective, retinal detachment and IOL subluxations occurred. Other posterior chamber pIOLs should be used until the complications associated with the PRL pIOL are resolved.

Cataractous Changes due to Posterior Chamber Flattening with a Posterior Chamber Phakic Intraocular Lens Secondary to the Administration of Pilocarpine

OBJECTIVE

To present the first reported case of cataract formation as a consequence of instillation of pilocarpine in an eye with a posterior chamber phakic intraocular lens (IOL).

DESIGN

Interventional case report.

INTERVENTION

A 46-year-old man received a hyperopic implantable collamer lens (ICL) bilaterally.

MAIN OUTCOME MEASURES

Determination of best-corrected visual acuity (BCVA); contrast sensitivity testing with and without glare; and intraocular pressure (IOP), specular endothelial cell, and slit-lamp examinations were performed serially. In addition, the distance between the ICL and crystalline lens was measured with optical coherence tomography.

RESULTS

Both eyes underwent uneventful ICL implantation for the correction of a manifest spherical equivalent of +7 diopters (D) in the right eye and +7.1 D in the left eye. The left eye was followed for 2 years without developing complications. The right eye, however, showed on the first postoperative day a fleckenlike opacification on the anterior pole of the crystalline lens after instillation on the operative day of 2% pilocarpine in an attempt to accelerate recovery from unwanted pupil dilation causing patient complaints of glare disability after surgery. Optical coherence tomography demonstrated complete contact of the ICL with the natural lens 24 hours postoperatively. Serial IOP measurements were always within the normal limits. The instillation of 1% cyclopentolate resulted in an increase in the ICL vault that measured 132 mum 24 hours later. Three days after the completion of a 3-day course of topical 1% cyclopentolate, the opacification was less dense and demarcated, and a 124-mum vault was measured. Three months postoperatively, the cataract was associated with a 3-line loss of BCVA and considerable degradation of the contrast sensitivity, especially at higher spatial frequencies and with a glare source, and corneal endothelial cell changes were within normal limits. One year after ICL implantation, the right eye had to undergo phacoemulsification and IOL implantation, which were uneventful.

CONCLUSIONS

Posterior chamber flattening with resulting crystalline lens opacification can occur immediately after the instillation of pilocarpine in an eye with a hyperopic ICL. Therefore, caution should be taken with the administration of cholinergic agonists such as pilocarpine in patients with phakic IOLs, at least if they are hyperopic ICLs.

Surgical Correction of Hyperopia

Surgical attempts to correct hyperopia have yielded varying results over the last 130 years. These techniques include the reshaping of the cornea through incisions, burns, or lamellar cuts with removal of peripheral tissue; the addition of central inlays; laser ablations; and the replacement of the crystalline lens. By examining the success of each surgical technique, the refractive surgeon may be able to make an informed decision on its indications and limitations, based on the specific patient's characteristics. Reporting the outcomes and complications of hyperopic surgery will help refine our approach to the management of an increasingly hyperopic and presbyopic population.

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 the crystalline lens resulting from insertion of a phakic IOL (ICL) into the porcine eye

BACKGROUND

Insertion of a phakic IOL offers these advantages: the corneal optical zone is not dissected or resected; preservation of the crystalline lens results in preservation of the accommodation force; and since the phakic IOL is removable, any error or change in refraction can be countered by exchanging it. However, the cause of secondary cataracts has never been clarified or discussed to date.

METHODS

The following ICL lenses were inserted under general anaesthesia into 20 eyes of ten 3-month-old miniature pigs: a minus lens without holes into five eyes, a plus lens in two eyes, a minus lens with four holes around the lens haptics in three eyes, and a minus lens with a central hole in the optic in three eyes; and seven eyes were used as controls. The anterior segments were then photographed 1 week, 1 month and 3 months after surgery. At 3 months after surgery, Evans blue (EB) was infused into the vitreous under general anaesthesia, and after 30 min, the eyeball was enucleated, fixed and examined.

RESULTS

In the case of the ICL without holes, the anterior subcapsular opacities were observed in all the eyes, and the anterior surfaces of the crystalline lenses were not stained with EB. Use of the ICL with four holes around the lens haptics resulted in light staining of the anterior surface of the crystalline lens, but the anterior subcapsular opacities observed were mild. As for the ICL with a hole in the centre of the optic, the anterior surface of the crystalline lens was stained and no anterior subcapsular opacities were observed.

CONCLUSION

The results suggested that the insertion of an ICL brings about a change in the dynamics of the intraocular aqueous humour, reducing its circulation to the anterior surface of the crystalline lens. This is considered to cause a metabolic disturbance of the crystalline lens, resulting in anterior subcapsular opacification.

Outcome of simultaneous phakic implantable contact lens removal with cataract extraction and pseudophakic intraocular lens implantation

PURPOSE

To assess the outcome of simultaneous implantable contact lens (ICL) removal and cataract extraction with pseudophakic intraocular lens (IOL) implantation.

SETTING

CODET Aris Vision Institute, Tijuana, Mexico.

METHODS

This retrospective noncomparative interventional case series evaluated 14 eyes of 12 patients with ICL implantations who developed a cataract and simultaneously had ICL removal and cataract extraction with IOL implantation. The follow-up time was at least 6 months (range 6 to 24 months). Visual acuity (logMAR), manifest refraction, intraocular pressure, and adverse events were recorded.

RESULTS

Of the 12 patients (14 eyes), 10 patients (12 eyes) had ICL surgery to correct high myopia and 2 patients (2 eyes), to correct hyperopia. The mean uncorrected visual acuity after ICL implantation (before cataract development), before cataract surgery, and after cataract surgery were 0.48 +/- 0.32, 0.83 +/- 0.34, and 0.40 +/- 0.27, respectively. The mean best corrected visual acuity (BCVA) before ICL implantation, after ICL implantation, and after cataract surgery were 0.31 +/- 0.21, 0.28 +/- 0.19, and 0.27 +/- 0.21, respectively. The mean final manifest spherical equivalent was 0.30 diopters (D) +/- 1.07 (SD) (range +2.38 to 2.0 D). Ten eyes (71.4%) were within +/-1.0 D of the calculated target. One eye had a tear in the posterior capsule with vitreous loss during cataract surgery. No other intraoperative, perioperative, or postoperative complications were observed. No loss of BCVA was recorded at the last postoperative visit.

CONCLUSIONS

Lens opacities and cataract formation are a potential complication of ICL surgery. The removal of the ICL and the cataract with IOL implantation was found to be safe, with predictable refractive results.

Toric phakic intraocular lens for the correction of hyperopia and astigmatism

PURPOSE

To evaluate the Artisan toric phakic intraocular lens (pIOL) for the correction of hyperopia and astigmatism.

SETTING

Department of Ophthalmology, Erasmus MC, Rotterdam, The Netherlands, and Department of Ophthalmology, Sint Truiden, Belgium.

METHODS

In this prospective study of 47 eyes of 28 patients with hyperopia and astigmatism, Artisan toric pIOLs were implanted between April 1999 and June 2004. Uncorrected visual acuity (UCVA), best corrected visual acuity, refraction, astigmatism, safety, and predictability were analyzed. Change in astigmatism was analyzed with vector analysis. Refractive cylinders are expressed in minus form.

RESULTS

Mean preoperative spherical equivalent was +4.33 diopters (D) +/- 2.26 (SD). Mean follow-up was 11.1 months (range 6 to 36 months). A gain of 1 or more lines in best spectacle-corrected visual acuity (BSCVA) was seen in 36.2%. Safety index and efficacy index after 6 months were 1.06 and 0.87, respectively. The mean postoperative astigmatism at 6 months was 0.19 D at an axis of 144 degrees. At 6 months, about three quarters (76.6%) of the eyes had a UCVA of 20/40 or better. One eye lost 2 lines of BSCVA. In 1 eye, the lens position had to be changed because of a large axis misalignment. No serious complications developed in any of the treated eyes during follow-up.

CONCLUSIONS

Artisan toric pIOLs can correct moderate to high hyperopia combined with astigmatism with good refractive results. In this study, there were no serious complications. However, the predictability of the refractive results appeared to be lower than those in the correction of myopia and astigmatism with toric Artisan lenses.

Results of cataract extraction after implantable contact lens removal

PURPOSE

To evaluate the visual results following insertion of implantable contact lenses (ICLs) in ametropic eyes and the development of subcapsular opacification with visual loss and to examine the anterior capsule, including the subcapsular tissue alteration, by light microscopy.

SETTING

Department of Ophthalmology, Schlosspark-Klinik, affiliated hospital of the Charité Berlin, Humbold University, Berlin, Germany.

METHODS

A prospective noncomparative interventional case series of anterior subcapsular cataracts in 9 of 127 (7.1%) patient eyes receiving ICLs to correct myopia and hyperopia was studied. The cataracts were phacoemulsified due to visual loss, and an intraocular lens (IOL) was implanted in the bag. After capsulorhexis, the anterior capsule was withdrawn for light microscopy examination. Visual acuity in each eye was measured before and after ICL implantation and before and after cataract extraction. The age range of cataract patients was 39 to 53 years.

RESULTS

Implantable contact lens removal and phacoemulsification with IOL implantation for emmetropia resulted in an increased visual acuity compared to initial vision. Four of 28 hyperopic eyes (14.3%) developed subcapsular central opacification after ICL implantation, whereas 5 of 99 myopic patients (5.1%) developed opacifications.

CONCLUSIONS

Patients should be informed prior to ICL implantation, there is a possibility of secondary subcapsular cataract formation and vision reduction. Although the posterior chamber inlay as well as the cataract can be removed and better acuity can be restored, a possible complication due to the ICL implantation cannot be avoided and the accommodation in young patients lost.

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.

Pupillary capture of implantable contact lens after blunt trauma

A 33-year-old woman visited our clinic with blurry vision and periorbital swelling after experiencing blunt trauma to left eye. Ten months earlier, she had implantable contact lens (ICL) implantation in the left eye. Biomicroscopic examination showed that that 1 footplate of the ICL was entrapped in the pupillary aperture at the 7 o'clock position and the ICL was placed vertically. The patient had limited ocular movement in lateral gaze, and the computed tomography showed a medial orbital wall fracture. Pupillary capture of the ICL was surgically corrected with an iris manipulator under topical anesthesia. After the ICL was repositioned, the patient's uncorrected visual acuity was restored to 20/32, as before the injury. Pupillary capture of the ICL may occur after blunt ocular trauma.

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.

Clinical outcomes of phakic refractive lens in myopic and hyperopic eyes: 1-year results

PURPOSE

To confirm the safety, efficacy, and predictability of the surgical correction of myopia and hyperopia with the phakic refractive lens (PRL) (Medennium Inc.).

SETTING

St. Eriks Eye Hospital, Stockholm, Sweden.

METHODS

This was a prospective clinical study of 20 eyes, 14 myopic and 6 hyperopic, that had PRL implantation at St. Eriks Eye Hospital from April to November 2002. Examinations were performed preoperatively and 1 day, 1 week, 3 months, and 1 year postoperatively. Follow-up included evaluation of the PRL rotation with retroillumination photography, evaluation of the distance between the PRL and the crystalline lens with Scheimpflug image, laser flare, endothelial cell count, uncorrected (UCVA) and best corrected (BCVA) visual acuity, residual refractive error, refractive stability, intraocular pressure, and induced cataract.

RESULTS

Postoperatively, 11 eyes (55%) gained 1 or more lines, 5 eyes (25%) had no change, and 4 eyes (20%) lost 1 line of BCVA. No eye lost 2 or more lines. Mean UCVA was 0.87+/- 0.29 postoperatively. Laser flare values were highest 1 day after operation with normalization at 3 months and without changes at 1 year (P<.05). A rotation of 10 degrees or more was found in 15 eyes (75%) during the first year. The distance between the PRL and crystalline lens was considerably less at 1 year than at baseline (P<.05). There was no statistically significant endothelial cell loss induced by the PRL (P<.05). No induced cataract, glaucoma, or inflammation was observed. In 1 hyperopic eye, horizontal iris transillumination defects were noticed at 1 year.

CONCLUSION

Safety and efficacy indexes were high at 1-year follow-up. The PRL rotated slightly in the posterior chamber. The distance between the PRL and the crystalline lens was considerably less at 1 year than at baseline.

Long-term results of implantation of phakic posterior chamber intraocular lenses

PURPOSE

To study the incidence and progression of lens opacification after implantation of phakic posterior chamber intraocular lenses for myopia and its correlation with vaulting and endothelial cell density (ECD).

SETTING

Department of Ophthalmology, University of Vienna Medical School, Vienna, Austria.

METHODS

An implantable contact lens (ICL V4, Staar Surgical Inc.) was inserted in 76 myopic eyes. Patients were prospectively followed preoperatively and at 1, 3, 6, 12, 24, and 36 months. The uncorrected visual acuity and best corrected visual acuity (BCVA) were determined. Vaulting was measured optically with a Jaeger II pachymeter, and the crystalline lens was examined at the slitlamp for the presence and characteristics of opacification. Endothelial cell morphometry was performed by specular microscopy, and the ECD was calculated. Eyes in which lens opacification developed were followed for at least 12 months to determine the degree and course of visual impairment.

RESULTS

Lens opacification occurred in 11 eyes (14.5%). Opacification was correlated with intraoperative trauma to the crystalline lens, age older than 50 years, and decreased ECD values throughout the observation period. Vaulting of the ICL did not correlate with the risk for lens opacification. After onset of lens opacification, 6 eyes (55%) had a stable BCVA within +/-0.5 lines and 5 eyes had progressive opacification, losing between 3.5 lines and 0.5 lines (mean 1.8 lines +/- 1.1 [SD]). Three eyes (3.9%) in the progressive group had a 1- to 2-line loss of BCVA over preoperative values and subsequently had cataract surgery.

CONCLUSIONS

Risk factors for lens opacification after implantation of the model V4 ICL included intraoperative trauma to the crystalline lens and older age. Decreased ECD in eyes with opacification suggests ongoing inflammation as a cause. Patients younger than 45 years may have a significantly lower incidence of opacification.