Scanning electron microscopic characteristics of phakic intraocular lenses

Artisan versus Artiflex phakic intraocular lens implantation in the treatment of moderate to high myopia: meta-analysis

Background

To compare the postoperative safety, efficacy, predictability, visual quality and biomechanics after implantation of Artisan vs. Artiflex phakic intraocular lenses (PIOLs).

Methods

Pubmed, Embase, Cochrane Library were conducted up from January 2000 to February 2020. Comparative clinical studies reporting in accordance with the eligibility criteria were included in this meta-analysis. The pooled weighted mean differences (WMDs) and odds ratios (ORs) with corresponding 95% confidence intervals were calculated.

Results

Comparative trials with myopia patients were selected in this review. The pooled WMD and OR estimates statistical significance in terms of postoperative best corrected visual acuity (BCVA), efficacy, postoperative spherical equivalence (SE), predictability, contrast sensitivity and mean intraocular higher-order aberrations (HOA) (mm) for a 6-mm pupil, manifesting that Artiflex PIOL showed evident beneficial effect for correcting myopia compared to Artisan PIOL. There was no significant difference in the incidence of complications between the two groups.

Conclusion

Both of two techniques were safe and effective for myopia and compared to Artisan PIOL, Artiflex PIOL had significant improvement in efficacy, predictability, contrast sensitivityand HOA, except safety and complications in the treatment of moderate to high myopia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01930-6.

Comparative Surface Imaging Study of Multifocal Diffractive Intraocular Lenses

PURPOSE

To analyse and compare the surface topography and roughness of three different types of diffractive multifocal IOLs.

METHODS

Using scanning electron microscope (SEM, Inspect F, 5.0 KV, maximum magnification up to 20,000) and atomic force microscope (AFM, Park Systems, XE-100, non-contact, area profile comparison, 10 × 10 µm, 40 × 40 µm), the surface quality of the following diffractive IOLs was studied: the AcrySof IQ PanOptix (Alcon, USA), the AT LARA 829MP (Carl Zeiss Meditec, Germany), and Tecnis Symfony (Johnson&Johnson Vision, USA). The measurements were made over three representative areas (central non-diffractive optic, central diffractive optic, and diffractive step) of each IOL. Roughness profile in terms of mean arithmetic roughness (R_a) and root-mean-squared roughness (R_q) values were obtained and compared statistically.

RESULTS

In SEM examination, all IOLs showed a smooth optical surface without any irregularities at low magnification. At higher magnification, Tecnis Symfony showed unique highly regular, concentric, and lineate structures in the diffractive optic area which could not be seen in the other studied diffractive IOLs. The differences in the measured R_a and R_q values of the Tecnis Symfony were statistically significant compared to the other models (p < 0.05).

CONCLUSION

Various different topographical traits were observed in three diffractive multifocal IOLs. The R_a values of all studied IOLs were within an acceptable range. Tecnis Symfony showed statistically significant higher surface R_a values at both central diffractive optic and diffractive step areas. Furthermore, compared to its counterparts, Tecnis Symfony demonstrated highly ordered, concentric pattern in its diffractive surfaces.

Middle- and long-term results after iris-fixated phakic intraocular lens implantation in myopic and hyperopic patients: a meta-analysis

The iris-fixated phakic intraocular lens (pIOL) has been available for over 25 years. To provide a clear picture of outcomes and risks, for this systematic review and meta-analysis, the literature was searched for reports on middle- and long-term effects. The iris-fixated phakic intraocular lens (pIOL) has been available for over 25 years. To provide a clear picture of outcomes and risks, for this systematic review and meta-analysis, the literature was searched for reports on middle- and long-term effects of iris-fixated pIOLs on myopic and hyperopic eyes with a follow-up of at least 2 to 4 years. Visual and refractive results after implantation for correction of myopia are positive and the complication rate is low. Endothelial cell loss appears to be at an acceptable rate, although the range of endothelial cell change is too wide to draw firm conclusions. Care should be taken when considering an iris-fixated pIOL for hyperopic eyes because complication rates, particularly pigment dispersion, might be higher than those in myopic eyes. More well-designed, long-term studies are needed, especially in hyperopic eyes. The authors advocate for standardized reporting of refractive surgery data. Initiatives proposed by journal authors and editors to achieve uniformity should be supported.

Long-term In Vivo Stability of Posterior Chamber Phakic Intraocular Lens: Properties and Light Transmission Characteristics of Explants

PURPOSE

To evaluate the in vivo durability of the surface and optical properties of the implantable Collamer lens (ICL).

DESIGN

Retrospective case series.

METHODS

We included patients who developed cataracts after having undergone ICL implantation from March 2003 to May 2014 and underwent ICL explantation followed by cataract surgery from March 2017 to December 2019 at the Nagoya Eye Clinic. ICL explants were submitted to Chukyo Medical Co, Ltd (Nagoya City, Japan) for laboratory analysis using ultraviolet-visible light spectroscopy, light microscopy (LM), and scanning electron microscopy. Patients' demographic and clinical data were collected and reviewed.

RESULTS

Thirteen eyes from 10 patients were studied. The average age at ICL explantation was 50.5 ± 8.5 years (range, 34.5-66.3 years). The average length of ICL stay in the eye (from implantation to explantation) was 10.5 ± 2.7 years (range, 4.4-13.7 years). No opacification or coloring of the ICL explants was observed by LM. The ICL explants showed almost the same light transmittance as that of unused ICLs. Scanning electron microscopy revealed no irregularities at the surface of the center and periphery of the optic and haptic footplate. The positioning holes did not show any deposition.

CONCLUSION

The ICLs remained in-eye for >10 years without any deterioration in the surface and optical properties of the ICL, despite their contact with the ciliary body and iris tissues and the continuous interaction with the aqueous humor components. The present study shows long-term in vivo stability of the ICL.

Morphologic Differences Observed by Scanning Electron Microscopy According to the Reason for Pseudophakic IOL Explantation

Purpose

To compare variations in surface morphology, as studied by scanning electron microscopy (SEM), of explanted intraocular lenses (IOLs) concerning the cause leading to the explantation surgery.

Methods

In this prospective multicenter study, explanted IOLs were analyzed by SEM and energy-dispersive X-ray spectroscopy. The IOLs were explanted in the centers of the research group from 2006 to 2012. The primary procedure was phacoemulsification in all cases.

Results

The study evaluated 40 IOLs. The main causes for explantation were IOL dislocation, refractive error, and IOL opacification. Those explanted due to dislocation demonstrated calcifications in 8 lenses (50%), salt precipitates in 6 cases (37.5%), and erythrocytes and fibrosis/fibroblasts in 2 cases (12.5%). In the refractive error cases, the SEM showed proteins in 5 cases (45.5%) and salt precipitates in 4 lenses (36.4%). In IOL opacification, the findings were calcifications in 2 of the 3 lenses (66.6%) and proteins in 2 lenses (66.6%).

Conclusions

A marked variation in surface changes was observed by SEM. Findings did not correlate with cause for explantation. Scanning electron microscopy is a useful tool that provides exclusive information regarding the IOL biotolerance and its interactions with surrounding tissues.

Surface roughness of intraocular lenses with different dioptric powers assessed by atomic force microscopy

PURPOSE

To analyze the optic surface roughness and morphology of 2 types of hydrophobic acrylic intraocular lenses (IOLs) with various dioptric powers using atomic force microscopy (AFM).

SETTING

Technical University of Cluj-Napoca, Faculty of Mechanics, Cluj-Napoca, Romania.

METHODS

Atomic force microscopy was used to characterize the topography of 2 types of hydrophobic acrylic IOLs from a single manufacturer (SN60AT and SA30AL) with dioptric powers ranging from 10.0 diopters (D) to 30.0 D. The AFM analysis was performed in contact mode using a V-shaped silicon nitride cantilever with a pyramidal tip curvature of 15 nm and a nominal spring constant of 0.2 N/m. Detailed surface characterization of the IOL optic was obtained using 6 quantitative parameters provided by the AFM software.

RESULTS

Five of 6 roughness parameters indicated statistically significant differences (P<.05) between IOLs with different dioptric powers, with the 10.0 D IOL in both models providing the smoothest optic surface. Between models with the same dioptric power, the SN60AT model had lower values of each surface roughness parameter than the SA30AL model.

CONCLUSIONS

Atomic force microscopy was an accurate tool for assessing the surface properties of IOL optics. Manufacturing processes were responsible for introducing detectable differences in the topography of IOL biomaterials with identical copolymer constituents but different dioptric powers. Nanometric analysis may assist IOL manufacturers in developing IOLs with optimal surface characteristics.

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.

Position of rigid and foldable iris-fixated myopic phakic intraocular lenses evaluated by Scheimpflug photography

PURPOSE

To evaluate the postoperative intraocular positional stability of 1 rigid poly(methyl methacrylate) (PMMA) phakic intraocular lens (pIOL) model and 2 foldable polysilicone-PMMA iris-fixated pIOL models.

SETTING

Department of Ophthalmology, Johann Wolfgang Goethe-University Frankfurt am Main, Germany.

METHODS

One of 3 iris-fixated pIOL models (Artisan, Artiflex I, and Artiflex II, Ophtec BV) was implanted in 45 eyes of 26 patients with myopia or myopic astigmatism. The central distance between the pIOL and corneal endothelium and between the pIOL and anterior surface of the crystalline lens was evaluated using Scheimpflug photography 6 and 12 months after surgery.

RESULTS

The mean preoperative spherical equivalent was -9.32 diopters +/- 1.78 (SD) (range -6.5 to -13.5 D). Each IOL model was implanted in 15 eyes. The median distance from the central corneal endothelium to the anterior surface of the pIOL at 6 months and 12 months was 2.65 mm and 2.64 mm, respectively, in the Artisan group, 2.47 mm and 2.50 mm, respectively, in the Artiflex I group, and 2.48 mm and 2.52 mm, respectively, in the Artiflex II group. The median distance between the posterior surface of the pIOL and the anterior surface of the crystalline lens at 6 months and 12 months was 0.40 mm and 0.48 mm, respectively, in the Artisan group, 0.53 mm and 0.55 mm, respectively, in the Artiflex I group, and 0.68 mm and 0.66 mm, respectively, in the Artiflex II group. At 12 months, the distance between the pIOL and crystalline lens was statistically significantly greater in the Artiflex II group than in the Artisan group (P<.01).

CONCLUSION

The intraocular position of rigid pIOLs and foldable silicone iris-supported pIOLs showed a difference between the 3 pIOL models in space to the crystalline lens and the corneal endothelium, which may affect long-term results in terms of IOL interaction with surrounding tissue.

Posterior synechias following implantation of a foldable silicone iris-fixated phakic intraocular lens for the correction of myopia

A 45-year-old white woman with unilateral high myopia had uneventful implantation of a -9.0 diopter, foldable, iris-fixated Artiflex I anterior chamber phakic intraocular lens (pIOL) (Ophtec B.V.) in the right eye. Despite application of topical antibiotic and steroid agents for 4 weeks after surgery, iris pigment dispersion developed on the anterior surface of the crystalline lens. Two weeks later, the iris dispersion increased and posterior synechias developed from the iris to the crystalline lens next to the pIOL haptic at the 3 o'clock position. Consequently, pIOL re-enclavation was performed without surgically removing the posterior synechias. Initial and interim mydriatic and steroid eyedrops were administered 4 times a day. Regular follow-up examinations after re-enclavation (at 2, 3, 6, 12, and 24 months) confirmed a stable pIOL position by Scheimpflug photography. Two years after implantation, posterior synechias persisted at the 3 o'clock position, with iris dispersion on the crystalline lens and the posterior side of the pIOL, but with no signs of anterior chamber inflammation and no visual acuity loss.

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.

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.

Correction of Myopia of 7 to 24 Diopters With the Artisan Phakic Intraocular Lens: Two-year Follow-up

PURPOSE

To evaluate the safety and efficacy of the iris claw phakic intraocular lens (Artisan; Ophtec BV, Groningen, The Netherlands) in patients with high myopia.

METHODS

Between May 1999 and July 2001, 93 Artisan phakic intraocular lenses (IOLs) were implanted in 60 patients affected by high myopia. All patients underwent 24-month follow-up. The power of the lenses ranged from -7.5 to -22.0 diopters (D). Patients were divided into two groups: group 1 (68 eyes), myopia -6.75 to -15.50 D (SE), and group 2 (25 eyes), myopia -16.0 to -23.0 D (SE). Pre- and postoperative patient evaluation included manifest and cycloplegic refractions, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), endothelial cell count, intraocular pressure, complication rate, safety, and efficacy.

RESULTS

At 4 months, 83.8% (57/68) (group 1, myopia -6.75 to -15.50 D) and 68% (17/25) (group 2, myopia -16.0 to -23.0 D) of eyes achieved UCVA of > or =20/40. The BSCVA remained the same or improved in 100% of eyes. After 4 months, 69.1% (47/68) of eyes in group 1 and 52% (13/25) of eyes in group 2 were within +/-1.00 D of the desired refraction; the mean refraction was stable between 4 and 24 months. Of the intraoperative complications, 69.2% were observed in the first 25 lenses implanted; postoperative complications included iris atrophy in 11.8% (11/93), lens decentration in 5.4% (5/93), and night glare in 6.4% (6/93) of eyes. No IOLs were removed. Mean endothelial cell loss was 2.8% at 4 months, 3.9% at 12 months, and 5.4% at 24 months.

CONCLUSIONS

Our results regarding implantation of the Artisan phakic IOL confirm that these lenses are safe and effective for the correction of high myopia, with a stable refractive outcome but with a higher than normal rate of endothelial cell loss during 2-year follow-up.

Ten-year follow-up of a ciliary sulcus-fixated silicone phakic posterior chamber intraocular lens

In 1992, a ciliary sulcus-fixated, silicone, phakic posterior chamber intraocular lens (PPC IOL) (Adatomed, Fyodorov type) was implanted in both eyes of a 42-year-old white woman to correct high myopia (right eye, -17.0 diopters [D]; left eye, -11.5 D). In the right eye, localized cortical opacification was present in the anterior part of the natural lens preoperatively but did not progress during a 10-year follow-up period. With Scheimpflug photography, it was possible to detect a space between the natural lens and the IOL that was not evident on slitlamp examination. Maintenance of space between an IOL and the natural lens appears to be an important factor in preventing cataract formation after PPC IOL implantation.

Position of angle-supported, iris-fixated, and ciliary sulcus-implanted myopic phakic intraocular lenses evaluated by Scheimpflug photography

PURPOSE

To examine postoperative positional stability of myopic phakic intraocular lenses (IOLs).

DESIGN

Prospective, nonrandomized clinical study.

METHODS

The study included 46 eyes which received an anterior chamber angle-supported (Bausch & Lomb NuVita; 10 eyes), anterior chamber iris-fixated (Ophtec Artisan; 20 eyes) or ciliary sulcus-implanted phakic IOL (Staar ICL; 16 eyes). The distance between the phakic IOL and the crystalline lens and the cornea as well as rotation around the optical axis was evaluated using Scheimpflug photography at 1, 3 to 6, and 12 months postsurgery.

RESULTS

The anterior chamber phakic IOLs showed no significant movement in anteroposterior direction. The posterior chamber phakic IOL showed a significant movement toward the crystalline lens between postoperative months 3 and 12. The median amount of rotation around the optical axis between the 3- and the 12-month evaluation was 1.9 degrees (range = 0.0-33.5 degrees) for the NuVita, 0.6 degrees (range = 0.0-3.5 degrees) for the Artisan, and 0.9 degrees (range = 0.2-2.3 degrees) for the ICL. Four NuVita IOLs rotated more than 10 degrees.

CONCLUSIONS

The angle-supported anterior chamber phakic IOLs showed a generally stable position regarding distance to cornea and natural lens, but rotation was observed in four IOLs. The iris-fixated phakic IOL showed the highest overall stability. The posterior chamber phakic IOL was stable in terms of rotation but had a tendency to decrease in distance toward the crystalline lens. Intraocular lenses implanted in phakic eyes followed for 12 months demonstrate stable IOL position overall.

Acute haptic-induced pigmentary glaucoma with an AcrySof intraocular lens

A 49-year-old man had uneventful endocapsular phacoemulsification with in-the-bag implantation of an AcrySof SA60AT single-piece intraocular lens (IOL) (Alcon) in the right eye. Twenty-seven days postoperatively, he presented with ocular pain, intraocular pressure of 48 mm Hg, 360 degrees of hyperpigmentation of the trabecular meshwork, and iris pigment epithelial atrophy in the region of the upper temporal haptic, which had dislocated into the sulcus. The patient made an excellent recovery following IOL removal and exchange. Scanning electron microscopy of the explanted IOL demonstrated that the haptic had a rough lateral surface and anterolateral edge. We do not think this IOL should be implanted in the sulcus placement of the heptics. In this article, we report the case of a patient with an AcrySof SA60ATIOL (Alcon) who developed acute pigmentary glaucoma when the inferior haptic slipped out of the bag and came into contact with the pigmented iris and ciliary body.

Phakic intraocular lenses

Since Zaldivar's review of phakic intraocular lenses in these pages in 2000 [1**], further reports of experience with this technology have emerged. Their relative advantages and disadvantages over competing technologies are becoming clearer. Clinical trials, including Food & Drug Administration (FDA) trials, have shown predictability, stability, and efficacy. Safety of these implants over the long term remains a concern, but in some situations, at least, phakic intraocular lenses are becoming the refractive correction of choice. This brief review looks at the most recent data to emerge regarding phakic intraocular lenses.

Gonioscopic changes after implantation of a posterior chamber lens in phakic myopic eyes

PURPOSE

To evaluate the effects of posterior chamber implantation of phakic intraocular lenses on angle structures and the correlation with intraocular pressure (IOP).

SETTING

Department of Ophthalmology, University Hospital of Vienna, Vienna, Austria.

METHODS

A Staar implantable contact lens (ICL) was implanted in 20 white patients (34 eyes) with high myopia. The patients were followed for a mean of 2.3 years (range 0.8 to 6.0 years). Two subgroups were created: One had a follow-up of 2.4 to 6.0 years and the other, 0.8 to 2.3 years. The mean spherical power of the implanted ICL was -16.8 diopters (D) (range -9.0 to -21.0 D). The angle structures were examined by gonioscopy using the Spaeth technique, and optical pachymetry and IOP were measured in dilated and undilated pupils. Trabecular pigmentation was measured semiquantitatively. The ICL models included a few prototypes (6 eyes), the V2 model (10 eyes), the V3 model (6 eyes), and the V4 model (12 eyes).

RESULTS

The anterior chamber angle was between 11 and 20 degrees in 41% of eyes, between 21 and 30 degrees in 21%, larger than 30 degrees in 21%, and 10 degrees or smaller in 17%. An apparent iris root insertion was above Schwalbe's line in 6% of eyes, behind Schwalbe's line in 12%, at the scleral spur in 67%, and in a deep angle recess behind the scleral spur in 15%. The curvature of the iris was regular in 19 eyes and steep in 15 eyes. The mean pigmentation in all 4 quadrants was 1.3. (Grade 1 was defined as trace pigmentation.) The mean pachymetry from the endothelium to the ICL anterior surface was 2.7 mm and from the endothelium to the anterior surface of the crystalline lens, 3.2 mm. The mean IOP was 14.1 mm Hg in undilated pupils and 12.1 mm Hg in dilated pupils. There was no correlation between angle pigmentation and IOP.

CONCLUSION

Trace pigmentation in the trabecular meshwork was common after ICL implantation. However, there was no direct influence on IOP. Long-term follow-up is necessary to evaluate the effect and progress of trabecular pigmentation in eyes with an ICL.