Pigment dispersion and Artisan phakic intraocular lenses

Enhanced ICL Sizing Accuracy Using Advanced Optical Coherence Tomography-Based Predictive Formula

PURPOSE

The aim of this study was to evaluate the accuracy of existing implantable collamer lens (ICL) sizing formulas, specifically the NK and KS formulas using CASIA2 and ANTERION devices, and to introduce a novel method aimed at improving the predictability of postoperative vault outcomes.

DESIGN

Retrospective case series.

METHODS

Preoperative measurements were taken using both CASIA2 and ANTERION devices. The efficacy of the NK and KS formulas, which are integrated into CASIA2, was assessed by comparing their predicted vault values against actual postoperative measurements obtained one month after surgery. A stepwise multiple regression analysis was performed with the aim of developing a new, more accurate predictive formula for optimal ICL sizing.

RESULTS

When compared to the existing NK and KS formulas, the new formula developed from ANTERION measurements demonstrated superior accuracy in predicting optimal ICL size, with a mean vault of 0.535 ± 0.200 mm, compared to 0.419 ± 0.172 mm and 0.466 ± 0.103 mm for the NK and KS formulas, respectively. The regression analysis identified several significant parameters influencing the determination of optimal ICL size.

CONCLUSIONS

This study presents a novel formula for ICL sizing that leverages measurements from the ANTERION device, supported by a detailed multiple regression analysis. The findings suggest that this new approach significantly enhances the accuracy of ICL size prediction, potentially reducing the risk of complications associated with improper sizing.

The Distribution of Crystalline Lens Rise in High Myopia Population and Its Influence on Vault After Implanting Intraocular Collamer Lens

INTRODUCTION

As a result of the insufficient ocular anatomical parameters used to customize implantable collamer lens (ICL), many patients still cannot achieve a suitable vault after ICL implantation surgery. This study analyzed the characteristics of a new anatomical parameter crystalline lens rise (CLR) in a population with high myopia and explored the influence of CLR on the vault after ICL implantation.

METHODS

Patients (298 eyes) with high myopia who underwent ICL implantation were enrolled to study CLR characteristics. Postoperatively, patients (159 eyes) were divided into five groups according to the value of CLR (A, CLR ≤ - 150; B, - 150 < CLR ≤ 0; C, 0 < CLR < 150; D, 150 ≤ CLR < 300; E, CLR ≥ 300 μm), and to investigate the correlation between CLR and vault.

RESULTS

In the 298 eyes, the CLR had a normal distribution (P = 0.35) and the mean CLR was 67.93 ± 150.66 μm. Ninety-nine eyes (33.22%) had a CLR ≤ 0 μm, of which 20 eyes (6.71%) had a CLR ≤ - 150 μm; 199 eyes (66.78%) had a CLR > 0 μm, of which 20 eyes (6.71%) had a CLR ≥ 300 μm. In 159 eyes, the CLR was negatively correlated with the vault at 1 day (R = - 0.497, P < 0.001), 3 months (R = - 0.505, P < 0.001), and 6 months (R = - 0.505, P < 0.001) postoperatively. At 6 months, the vault of group A was statistically significantly different compared to groups B-E (all P < 0.05), and that of group E was statistically significantly different compared to groups A-D (all P < 0.001). The remaining groups did not show statistically significant differences (all P > 0.05).

CONCLUSION

The CLR had a normal distribution in the high myopia population, and 13.42% of the CLR values were extreme (CLR ≤ - 150 μm or CLR ≥ 300 μm). A larger ICL diameter than that recommended by the manufacturer should be considered when the CLR is ≥ 300 μm and a smaller ICL diameter should be considered when the CLR is ≤ - 150 μm.

Refractive outcome in combined phacovitrectomy: Anterior segment changes and corrective factor for IOL power calculation improvement

PURPOSE

To analyze differences in refractive outcome Δ (difference between postoperative and expected refractive error) and in anterior segment changes between cataract surgery patients and combined phacovitrectomy patients. We also aimed to provide a corrective formula allowing to minimise the refractive outcome Δ in combined surgery patients.

METHODS

Candidates for phacoemulsification and combined phacovitrectomy (respectively PHACO and COMBINED groups) were prospectively enrolled in two specialised centres. Patients underwent best corrected visual acuity (BCVA) assessment, ultra-high speed anterior segment optical coherence tomography (OCT), gonioscopy, retinal OCT, slit lamp examination and biometry at baseline, 6 weeks postoperatively and 3 months postoperatively.

RESULTS

No differences in refractive Δ, refractive error and anterior segment parameters were noted between PHACO and COMBINED group (109 and 110 patients respectively) at 6 weeks. At 3 months, COMBINED group showed a spherical equivalent of -0.29 ± 0.10 D versus -0.03 ± 0.15 D in PHACO group (p = 0.023). COMBINED group showed a significantly higher Crystalline Lens Rise (CLR), angle-to-angle (ATA) and anterior chamber width (ACW) and a significantly lower anterior chamber depth (ACD) and refractive Δ with all 4 considered formulas at 3 months. For IOL power lower than 15, a hyperopic shift was observed instead.

CONCLUSIONS

Anterior segment OCT suggests anterior displacement of the effective lens position in patients undergoing phacovitrectomy. A corrective formula can be applied to IOL power calculation to minimize undesired refractive error.

The Non-uniform Distribution of Horizontal and Vertical Crystalline Lens Rise Using Optical Coherence Tomography

PURPOSE

To observe the crystalline lens rise (CLR) in horizontal and vertical orientations using anterior segment optical coherence tomography (AS-OCT).

METHODS

Non-invasive swept-source AS-OCT was used to measure the lens thickness, CLR, and angle-to-angle distance (ATA) in both the horizontal and vertical orientations. Anterior chamber depth (ACD) and horizontal white-to-white corneal diameter were obtained using the Pentacam HR (Oculus Optikgeräte GmbH). Axial length was obtained using the IOLMaster 700 (Carl Zeiss Meditec AG). The paired t test was used to analyze the difference in CLR between the two orientations. Pearson correlation analysis was performed to investigate the correlations between CLR and other ocular variables.

RESULTS

This prospective observational study comprised 99 eyes (99 patients) that underwent Visian Implantable Collamer Lens (STAAR Surgical) implantation for myopic correction. The mean CLR was 64.29 ± 168.04 and 208.09 ± 173.12 µm in the horizontal and vertical orientations, respectively. The vertical CLR (VCLR) was significantly greater than the horizontal CLR (HCLR) (P < .05). Both the HCLR and VCLR were positively correlated with lens thickness and negatively correlated with ACD (all P < .05). The difference in CLR (VCLR-HCLR) was positively correlated with the axial length and the difference in ATA between the two orientations (P < .05).

CONCLUSIONS

VCLR was greater than HCLR in most patients with myopia, especially in the longer eyes. This nonuniform distribution in CLR implied different placements of the iridocorneal angles in the horizontal and vertical orientations and should be considered for the selection of ICL size and placement position. [J Refract Surg. 2023;39(5):354-359.].

Repeatability and Agreement of Horizontal Corneal Diameter Measurements Between Scanning-Slit Topography, Dual Rotating Scheimpflug Camera With Placido Disc Tomography, Placido Disc Topography, and Optical Coherence Tomography

PURPOSE

The purpose of this study was to assess the repeatability and agreement of horizontal white-to-white (WTW) measurements using 4 different imaging modalities including a slit-scanning elevation topographer, dual rotating Scheimpflug camera and Placido Disc tomographer, Placido Disc topographer, and anterior segment optical coherence (OCT) tomographer.

METHODS

In this prospective study, 33 eyes of 33 healthy subjects were scanned 3 times using each of the Orbscan IIz, Sirius, Nidek OPD III, and DRI OCT Triton devices and WTW measurements were recorded. Repeatability was assessed using the intraclass correlation coefficient (ICC), and agreement was analyzed using Bland-Altman plots.

RESULTS

Mean WTW values obtained from the Orbscan IIz, Sirius, Nidek, and DRI OCT Triton devices were 11.76 ± 0.41, 12.10 ± 0.45, 12.14 ± 0.41, and 12.40 ± 0.48 mm, respectively. Overall, there was high repeatability, with the ICC >0.86 for all devices. The Sirius showed the highest repeatability (ICC = 0.993), and the Nidek the lowest (ICC = 0.870). All pairwise comparison showed significant differences in the mean WTW measurements ( P < 0.01) except between Sirius and Nidek ( P = 0.27). Mean differences showed that the DRI OCT Triton had the highest WTW values, followed by Nidek, Sirius, and finally by Orbscan, which provided the lowest measurements. All pairwise comparisons had wide limits of agreements (between 0.60 and 0.80 mm).

CONCLUSIONS

In healthy subjects the 4 devices demonstrated high repeatability in WTW measurement. However, a poor agreement between the devices suggests that they should not be used interchangeably for WTW measurements in clinical practice.

New Sizing Parameters and Model for Predicting Postoperative Vault for the Implantable Collamer Lens Posterior Chamber Phakic Intraocular Lens

PURPOSE

To identify parameters influencing the postoperative vault of the Implantable Collamer Lens (ICL) (STAAR Surgical) using the Artemis Insight 100 very high-frequency (VHF) digital ultrasound robotic scanner (ArcScan, Inc) and develop a model to improve lens vault prediction.

METHODS

This was a retrospective analysis of 147 consecutive V4c EVO and EVO+ ICL implantation procedures performed over three phases in myopic eyes. In the initial phase, lens size was defined by published sulcus-to-sulcus and crystalline lens rise measurements (Kojima formula) from VHF digital ultrasound biometry. From these data, a stepwise multivariate regression analysis was performed to develop a model for predicting central vault including the following variables: ICL size, ICL power, sulcus-to-sulcus (STS), ciliary body inner diameter (CBID), zonule-to-zonule, STS lens rise (STSL), ACD, anterior chamber angle, scotopic pupil diameter (SPD), angle-to-angle, and white-to-white diameter. The resulting regression model was used in coordination with the Kojima formula to select the lens size for the next series of eyes. The regression analysis was then repeated and a further series were treated. The postoperative achieved vault at 1 month was compared to the target vault predicted by the formula. A comparison analysis of the new model was made to previously published lens sizing formulas.

RESULTS

Statistically significant variables were ICL size, ICL power, CBID, STSL, and SPD. The primary 42 eyes (Kojima formula) achieved a mean vault of 506 ± 233 µm, a range of 810 µm (114 to 924 µm), and an interquartile range (IQR) of 391 µm. Using the Reinstein formula v1.0 for the next 36 eyes, the mean vault relative to target was +7 ± 123 µm, range of 569 µm (-278 to +291 µm), and IQR of 169 µm. Using the Reinstein formula v2.0 for the next 69 eyes, the mean vault relative to target was +67 ± 121 µm, range of 573 µm (-219 to +354 µm), and IQR of 131 µm. The achieved vault was within ±100, ±200, and ±300 µm of target in 33%, 50%, and 74% of eyes, respectively, for the training group, 58%, 89%, and 100% for the Reinstein formula v1.0 group, and 62%, 84%, and 94% for the Reinstein formula v2.0 group.

CONCLUSIONS

This is the first report describing the ciliary body inner diameter, which proved to be more highly correlated with vault than STS, and thus CIBD supersedes STS from the previous widely accepted improvement over WTW sizing. The new model also found scotopic pupil size to be a significant predictor, which has not been a part of any previously published model. The significant improvement in vault predictability afforded by these parameters and the new model enables charting attempted versus achieved vault outcomes for the first time. [J Refract Surg. 2022;38(5):272-279.].

Role of AS-OCT in Managing Corneal Disorders

Optical coherence tomography (OCT) is analogous to ultrasound biometry in the cross sectional imaging of ocular tissues. Development of current devices with deeper penetration and higher resolution has made it popular tool in clinics for visualization of anterior segment structures. In this review, the authors discussed the application of AS-OCT for diagnosis and management of various corneal and ocular surface disorders. Further, recent developments in the application of the device for pediatric corneal disorders and extending the application of OCT angiography for anterior segment are introduced.

Lens-vault analysis and its correlation with other biometric parameters using swept-source OCT

PURPOSE

To measure lens vault (LV) and to assess its correlation with various ocular parameters in healthy eyes, using for all measurements the same high-resolution swept-source optical coherence tomographer (SS-OCT).

METHODS

We prospectively recruited 67 Caucasian healthy patients whose mean age was 41.9 ± 12.4 years; only their right eye was included in the study. Data were all recorded with the ANTERION SS-OCT and comprised, for each patient, 5 consecutive measurements of LV, anterior chamber depth (ACD), lens thickness (LT), axial length (AL), white-to-white (WTW) distance, central corneal thickness (CCT), anterior chamber volume (ACV) and spur-to-spur (STS) distance.

RESULTS

Mean LV was 0.26 ± 0.23 mm (ranging from -0.24 to 0.78 mm). Data analysis revealed a statistically significant negative correlation between LV and ACD (R=-0.80, p < 0.001), AL (R = -0.36, p = 0.002), and ACV (R = -0.68, p < 0.001), and a positive correlation between LV and LT (R = 0.67, p < 0.001), and age (R = 0.53, p < 0.001). In contrast, no statistically significant correlation was found between LV and WTW (R=-0.17, p = 0.15), CCT (R = 0.11, p = 0.36) or STS (R=-0.10, p = 0.41).

CONCLUSIONS

Taking into account our findings about intra-parameter correlation levels, we believe that LV should be measured and analyzed together with other ocular parameters in clinical routine practice both for diagnosis and for some refractive surgeries.

Two-year results after combined phacoemulsification and iris-fixated phakic intraocular lens removal

PURPOSE

To describe and present results after a technique for cataract surgery combined with explantation of an iris-fixated phakic intraocular lens (IF-pIOL).

METHODS

The medical records of all patients, who had undergone cataract surgery combined with IF-pIOL explantation and subsequent implantation of a posterior chamber IOL by the Single Incision Technique (SIT), were reviewed. Data collection included preoperative and postoperative corrected distance visual acuity (CDVA), manifest refraction, and endothelial cell density (ECD) up to a follow-up time of 24 months.

RESULTS

Fifty myopic eyes (34 patients) and 9 hyperopic eyes (6 patients) had undergone a SIT procedure mainly because of cataract (67%). Postoperative CDVA improved in both the myopic eyes to 0.16 ± 0.37 logMAR, as in the hyperopic eyes to - 0.10 ± 0.55 logMAR with no eyes having loss of Snellen lines. Mean postoperative spherical equivalent was - 0.34 ± 0.72 D and - 0.10 ± 0.55 D, respectively. ECD loss 6 months after surgery was 5% and remained stable thereafter.

CONCLUSION

SIT for combined phacoemulsification and IF-pIOL removal yields good visual and refractive results and is a safe procedure in regard to ECD loss. The technique has advantages over the conventional procedure and is easy to perform.

Myopic Correction with Iris-Fixated Phakic Intraocular Lenses: Twelve-Year Results

PURPOSE

To evaluate a 12-year follow-up of myopic patients after iris-fixated phakic intraocular lenses (IF pIOLs) implantation. Setting. Ophthalmology Department, Military University Hospital in Prague (Czech Republic).

DESIGN

Single-center retrospective cohort study.

METHODS

We describe the results of a cohort study that included 85 eyes of 46 myopic patients who underwent implantation of Verisyse myopia, Veriflex, and Verisyse myopia toric (all Abbott Medical Optics, Inc.) intraocular lenses. Refractive functions and adverse events were assessed preoperatively, at 6 months, and 1, 2, 5, and 12 years after IF pIOL implantation.

RESULTS

Mean spherical equivalent was measured as -9.37 ± 2.87 D, 0.14 ± 0.61 D, and -0.42 ± 1.08 D, preoperatively, at 6 months and 12 years postoperatively, respectively. There was a significant reduction in the cylinder after surgery. At 12 years postoperatively, 90% of eyes had uncorrected distance visual acuity (UDVA) of 20/40 and 64% of 20/20. The safety index was 1.10 for the whole postoperative follow-up period. We found cataract formation in 3 eyes (3.5%). The endothelial cells loss (EC loss) directly caused by IF pIOL implantation was 6.0%, 8.10%, 12.8%, and 11.9%, at 1, 2, 5, and 12 years, respectively. In our cohort, 95% of eyes lost a higher percentage of EC than would be expected from a physiological loss at 12 years postoperatively. We found a significant negative interaction between preoperative pachymetry and EC loss, indicating that the lower pachymetry leads to a faster decline in endothelial cells density (ECD). IF pIOL re-enclavation was found in 28% of eyes. 7% of subluxations were caused by trauma. The mean time of nontraumatic re-enclavation was 6 years postoperatively.

CONCLUSIONS

The study confirmed the advantages of IF pIOL implantation due to rapid visual recovery and stable visual function over the 12-year follow-up and also showed the influence of lower corneal pachymetry regarding EC loss.

Determining vault size in implantable collamer lenses: preoperative anatomy and lens parameters

PURPOSE

To determine patient preoperative anatomical features and the parameters of implantable collamer lenses (ICLs) relevant in explaining vault variability.

SETTING

Ophthalmology Clinic Vista Sánchez Trancón, Badajoz, Spain.

DESIGN

Retrospective case series.

METHODS

This study comprised 360 eyes of 360 patients implanted with myopic or toric ICLs. Pentacam imaging was used for assessing white-to-white (WTW) diameter, central keratometry, and central corneal thickness. Anterior-segment optical coherence tomography was used to measure the horizontal anterior chamber angle distance (ATA), internal anterior chamber (ACQ), crystalline lens rise (CLR), anterior chamber angle (ACA), and vault. The sample was divided according to the implanted lens size (12.6 mm, 13.2 mm, and 13.7 mm). Vault predictors were identified from the variables above using multivariate regression analysis.

RESULTS

The groups showed significant statistical differences for WTW, ATA, ACQ, ACA, and vault (P < .007 for all). In general, bigger lenses were implanted in eyes with larger transverse sizes (WTW and ATA) and deeper ACQ. Also, larger ICL diameters were associated with higher vaults. Multivariate regression analysis identified the lens size (13.2 mm as reference; 12.6 mm: β [standardized coefficients] = -0.33; 13.7 mm: β = 0.42), ATA (β = -0.42), and CLR (β = -0.25), ICL spherical equivalent (β = -0.22) and patient age (β = -0.12) as predictors of the vault size (adjusted-R = 0.34 P < .001).

CONCLUSIONS

The multivariate model explained 34% of vault variability. The predictors indicated the presence of different mechanisms regulating the vault. These involved the difference between the transverse size of the eye and the ICL, the crystalline lens protrusion, and the ICL properties, such as power and size.

Implantation of an iris-fixated phakic intraocular lens for the correction of hyperopia: 15-year follow-up

PURPOSE

To assess the predictability, efficacy, stability, and safety of implantation of an Artisan iris-fixated phakic intraocular lens (IF-pIOL) for the correction of hyperopia with a follow-up of up to 15 years.

SETTING

Leiden University Medical Center, the Netherlands.

METHODS

Patients operated by a single surgeon up to 2007 were identified, and data on refraction, corrected distance visual acuity (CDVA), uncorrected distance visual acuity, endothelial cell (EC) density, and complications were collected.

RESULTS

A total of 61 eyes (32 patients) were analysed. The mean spherical equivalent decreased from +6.43 ± 1.78 diopters (D) preimplantation to -0.22 ± 0.57 D at 1 year postimplantation and remained stable throughout follow-up. A stable CDVA with safety indices ranging from 0.91 to 1.10 and efficacy indices between 0.43 and 0.86 were observed. Follow-up time had a significant effect on EC density with an estimated annual decline of 58 cells/mm2 after IF-pIOL implantation. IF-pIOL explantation was performed in a 10 eyes (16.4%) after 8.13 ± 5.11 years. The main reason for IF-pIOL explantation was EC loss (4 eyes [6.6%]). Pigment dispersion was the most encountered complication, observed in 9 eyes (14.8%).

CONCLUSIONS

Visual and refractive results after implantation of an IF-pIOL to correct hyperopia show favorable and stable results with long-term follow-up. Lifelong monitoring of EC counts is mandatory. Pigment dispersion might be a problem in hyperopic eyes implanted with an IF-pIOL; a shallower anterior chamber depth and a convex iris configuration might be predisposing factors.

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.

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.

Five-Year Endothelial Cell Loss After Implantation With Artiflex Myopia and Artiflex Toric Phakic Intraocular Lenses

PURPOSE

To evaluate the long-term changes in endothelial cell density (ECD) after the implantation of 2 types of foldable iris-fixated phakic intraocular lenses (pIOLs) for the treatment of myopia and astigmatism.

DESIGN

Prospective clinical cohort study.

METHODS

Two-hundred and ninety-three and 188 eyes implanted with, respectively, the Artiflex Myopia and Artiflex Toric (Ophtec B.V., Groningen, The Netherlands) iris-fixated pIOL for the treatment of myopia or astigmatism at the University Eye Clinic Maastricht as of January 2004. One-hundred and forty-six eyes from the myopic and 64 eyes from the toric groups completed a 5-year follow-up. Main outcome measures were chronic endothelial cell (EC) loss, percentage of eyes with a ≥25% decrease in ECD, and the percentage of eyes with an ECD < 1500 cells/mm².

RESULTS

Chronic EC loss showed an annual decline of 64 cells/mm² in the myopic (P < .001, standard error 3.58) and 62 cells/mm² in the toric (P < .001, standard error 3.77) groups. Total chronic EC loss from 6 months to 5 years postoperatively was 10.5% in the myopic and 10.2% in the toric groups. After 5 years, an ECD decrease of ≥25% occurred in 4.4% and 4.3% of eyes, and an ECD < 1500 cells/mm² was reported in 3.0% and 0.0% of eyes, respectively. Explantation of a pIOL owing to EC loss was required in 3.1% and 0% of eyes.

CONCLUSION

Chronic EC loss was around 10% over a 5-year period in eyes implanted with the foldable myopic (toric) pIOL. In up to 3.1% of eyes significant EC loss resulted in subsequent pIOL explantation.

Implantable Collamer Lens Sizing Method Based on Swept-Source Anterior Segment Optical Coherence Tomography

PURPOSE

To develop and evaluate the accuracy of a size-determination formula using anterior segment optical coherence tomography (AS-OCT) parameters.

DESIGN

Interventional case series.

METHODS

This study included 46 eyes of 23 patients with implantable collamer lens (ICL). Preoperatively, the anterior segment parameters were measured using high-frequency ultrasound biomicroscopy and AS-OCT. Three months postoperatively, the vaults were measured and the optimal ICL size was calculated using a previously published method. Stepwise multiple regression analysis was performed using the optimal ICL size as a dependent variable; the NK-formula was obtained. Thereafter, 35 eyes of 18 patients were implanted with ICL after the size was calculated using the NK-formula. Vaults measured at 3 months postoperatively were used to evaluate the accuracy of the NK-formula.

RESULTS

The distance between scleral spurs (ACW) and crystalline lens rise (CLR) were selected as significant parameters for the regression model (R² = 0.68, P < .05). There were 25 (71%), 8 (23%), and 2 (6%) eyes in the moderate, high, and low vault categories, respectively. Using the STAAR nomogram for ICL sizing, 24 eyes (69%) were fitted in the moderate vault. The mean absolute error of the predicted vault was significantly lower with the NK-formula (0.190 ± 0.129 mm) than with the STAAR nomogram (0.331 ± 0.235 mm, P = .002, paired t test).

CONCLUSION

AS-OCT is useful for ICL size determination, because it calculates the anterior segment parameters using automatic analysis. The NK-formula shows higher accuracy for predicting vault than the STAAR nomogram.

Severe pigment dispersion after iris-claw phakic intraocular lens implantation

A 23-year-old female patient presented 3 months after the implantation of an Artisan^® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. There was no loss of lines of corrected distance visual acuity. Severe pigment dispersion after the implantation of an Artisan^® phakic intraocular lens may happen and may require explantation of the lens. Iris depigmentation may improve with time.

Long-Term Endothelial Cell Loss in Patients with Artisan Myopia and Artisan Toric Phakic Intraocular Lenses: 5- and 10-Year Results

PURPOSE

To evaluate the long-term change in endothelial cell density (ECD) after the implantation of 2 types of rigid iris-fixated phakic intraocular lenses (pIOLs) for the treatment of myopia and astigmatism.

DESIGN

Prospective, clinical cohort study.

PARTICIPANTS

A total of 507 eyes of 289 patients receiving the Artisan Myopia or Artisan Toric (Ophtec B.V., Groningen, The Netherlands) iris-fixated pIOL for the treatment of myopia or astigmatism at the University Eye Clinic Maastricht as of January 1998.

METHODS

A total of 381 myopic and 126 toric pIOLs were implanted. Five- and 10-year follow-ups were completed by 193 and 127 eyes implanted with the myopic pIOL and by 40 and 20 eyes implanted with the toric pIOL, respectively.

MAIN OUTCOME MEASURES

Chronic endothelial cell (EC) loss, percentage of eyes with a decrease of ≥25% in ECD, and percentage of eyes with an ECD <1500 cells/mm².

RESULTS

Chronic EC loss was calculated from 6 months postoperatively to the end of follow-up and showed an annual ECD decline of 48 cells/mm² (standard error, 3.14) and 61 cells/mm² (standard error, 6.30) in the myopic (P < 0.001) and toric (P < 0.001) groups, respectively, resulting in a total EC loss of 16.6% and 21.5% from 6 months to 10 years postoperatively, respectively. Ten years after implantation, ECD had decreased by ≥25% in 7.9% and 6.3%, whereas ECD was <1500 cells/mm² in 3.9% and 4.0% in the myopic and toric groups, respectively. Explantation of the pIOL occurred in 6.0% in the myopic group and 4.8% in the toric group. Risk factors for increased EC loss were a shallow anterior chamber depth (ACD) (P ≤ 0.005) and a smaller distance between the central and peripheral pIOL edge to the endothelium (P ≤ 0.005).

CONCLUSIONS

A significant linear chronic EC loss was reported after implantation with myopic or toric iris-fixated pIOLs. A smaller ACD and smaller distance between pIOL edge and endothelium were risk factors for EC loss. Modification of preoperative age-related ECD thresholds is indicated to maintain an ECD that warrants safe future combined pIOL explantation and cataract surgery.

Chronic subclinical inflammation after phakic intraocular lenses implantation: Comparison between Artisan and Artiflex models

Purpose

To compare chronic subclinical inflammation induced after implantation of Artisan vs. Artiflex phakic intraocular lenses (pIOLs).

Methods

This prospective, comparative, non-randomized study included consecutive patients with moderate to high myopia who underwent Artisan or Artiflex pIOL implantation with standard surgery and postoperative care. Anterior chamber flare was assessed quantitatively using laser flare photometry (LFP) at baseline, 1 week, 1 month, 3 months, 6 months, and 2 years after surgery.

Results

PIOLs were implanted in 72 eyes (40 patients); Artisan pIOLs in 16 eyes (Artisan group) and Artiflex pIOLs in 56 eyes (Artiflex group). The mean preoperative anterior chamber flare was 6.5 ± 2.3 (range, 4.2–9.5) photons per millisecond (ph/ms) and 4.2 ± 0.9 (range, 2.5–11.7) ph/ms in Artisan and Artiflex groups, respectively (P = 0.400). In spite of early postoperative rise, the flare value returned to preoperative levels 6 months after pIOL implantation and remained stable up to 2 years. The amount of flare was not statistically different between Artisan and Artiflex groups in any postoperative follow-up (all P > 0.05). The trend in flare changes was not different between the studied groups (ANCOVA, P = 0.815).

Conclusion

The inflammatory response induced by implantation of either type of Artisan and Artiflex pIOLs is short-lived without statistically significant difference between the two models.

Removal of Persistent Cellular Deposits After Foldable Iris-Fixated Phakic IOL Implantation

PURPOSE

To report a case of severe recurrent cellular deposits after Artiflex intraocular lens (Ophtec B. V., Groningen, The Netherlands) implantation.

METHODS

Case report.

RESULTS

A 25-year-old woman underwent uneventful Artiflex intraocular lens implantation in both eyes. After 3 months, severe cellular deposits were seen in the posterior surface of the lens in one eye. Topical steroids were administered, with temporary improvement. Four months later, the deposits recurred and did not respond to topical steroids. Corrected distance visual acuity lost five lines. Treatment by polishing the posterior surface of the lens 10 months after the initial implantation was performed and resulted in complete visual recovery. No recurrence of the deposits were observed after 2 years of follow-up.

CONCLUSIONS

Persistent cellular deposits after Artiflex intraocular lens implantation may cause severe visual loss and may need surgical intervention. Polishing the posterior surface of the lens to mechanically remove the deposits was an effective long-term solution. [J Refract Surg. 2017;33(6):426-428.].

Characteristics of higher-order aberrations and anterior segment tomography in patients with pathologic myopia

PURPOSE

To investigate prospectively the characteristics in the higher-order aberrations and anterior segment tomography in patients with pathologic myopia.

METHODS

One hundred and twelve consecutive highly myopic patients (mean age 43.4 ± 9.3 years, spherical equivalent of refractive error ≥8 D and an axial length ≥26.5 mm) were studied. Thirty-seven emmetropic individuals (mean age 37.0 ± 14.5 years, spherical equivalent of refractive error ≤ ±1 D) were analyzed as controls. The ocular and cornea higher-order aberrations were measured using a Hartmann-Shack wavefront sensor (KR-1W; Topcon Corporation, Tokyo, Japan). The crystalline lens rise, the angle-to-angle, and the white-to-white values were measured using anterior segment OCT (SS-1000; Tomey Corporation, Nagoya, Japan). The mean curvature of the anterior corneal surface, the thickness at the thinnest central corneal point, the location of the central corneal point, the corneal volume, the anterior chamber volume, and the anterior chamber depth were measured using the Pentacam HR (Oculus, Inc., Wetzlar, Germany).

RESULTS

The ocular total higher-order aberration for 4-mm pupil, the ocular spherical aberrations, and internal spherical aberration for 6-mm pupil were significantly higher in highly myopic eyes than in the emmetropic controls. The crystalline lens rise was significantly smaller in highly myopic eyes than in the emmetropic controls. The anterior chamber depth and the anterior chamber volume were significantly larger in highly myopic eyes than in the emmetropic controls.

CONCLUSION

Highly myopic eyes had higher-order aberrations than emmetropic eyes because of the increasing internal aberrations.

Creeping posterior synechiae following hyperopic iris-fixated phakic implants

The purpose of this study was to report on the occurrence and management of posterior synechiae (PS) in three hyperopic eyes after iris-fixated anterior chamber phakic IOL implantation. This is a case report of a 55-year-old man and a 55-year-old lady who had undergone iris-fixated anterior chamber phakic IOL implantation to correct hyperopic astigmatism (one eye) and hyperopia (both eyes), respectively. The three eyes developed creeping PS and pigment dispersion within 4-6 weeks of surgery. Synechiolysis and pupil stretching in one eye did not work as the synechiae promptly recurred. Definitive management in the form of removal of the phakic implant and phacoemulsification with lens implant was successful in restoring normal vision in all three eyes. Although implantation of phakic intraocular lenses has been reported to be very effective for the correction of moderate to high degrees of ametropia, this complication can occur in hyperopic eyes. Pigment dispersion has been reported in myopic eyes also, but PS seem to be more an issue with hyperopic eyes. Age of the patient may also be a factor. This information is important in the selection and counselling of patients.

Influence of anterior segment biometric parameters on the anterior chamber angle width in eyes with angle closure

PURPOSE

To predict angle narrowing in eyes with angle closure in a Japanese population using anterior segment optical coherence tomography (AS-OCT) quantitative parameters.

PATIENTS AND METHODS

AS-OCT was used to examine 118 eyes of 118 patients with angle closure and 40 eyes of 40 patients with open angle under dark conditions. After measuring the angle opening distance 500 (AOD500), anterior chamber depth, iris thickness (IT), iris convexity (IC), pupil diameter, anterior chamber width, and crystalline lens rise, multivariate regression analyses were performed for the AOD500 in each group.

RESULTS

With the exception of IT, significant differences were observed between the AS-OCT parameters for the angle closure and open-angle groups. Anterior chamber depth, IT, and IC were the explanatory variables associated with AOD500 for each group (P≤0.001). A significant negative association was found between IT and IC only in the angle-closure group (P<0.001).

CONCLUSIONS

This study quantitatively confirmed that shallow anterior chamber depth was a major mechanism of angle narrowing, and that both IT and IC had a strong impact on angle narrowing. Moreover, the negative association found between IT and IC in only the angle closure group indicated the existence of the stretch force placed on the iris by relative pupillary block.

Endothelial distance after phakic iris-fixated intraocular lens implantation: a new safety reference

Purpose

To evaluate the distance between the endothelial surface of the cornea to the anterior edge of an Artiflex® phakic intraocular lens (IOL) implant to improve the safety profile of this implant.

Methods

This is a retrospective clinical case series of 45 patients who had Artiflex phakic IOL implantation (Artiflex p-IOL) with a follow-up period of 3 years. A Pentacam HR imaging system was used to measure the distance from various points of the anterior edge of the Artiflex IOL to the endothelial surface of the cornea, which we called endothelial–IOL (E–IOL) distance, in 45 eyes. The E–IOL distances were assessed at 1, 3, 6, 12, 24, and 36 months. Corresponding correlations of central endothelial distance to temporal and nasal edges and center of the IOL anterior surface were tabulated.

Results

Mean follow-up was 21.39±11.28 months. A statistically significant reduction of the E–IOL distance was observed over the follow-up period (P<0.05), with the mean annual reduction being 24.70 μm. A strong positive correlation between the E–IOL distance of the edges of the IOL and the central distance was observed (correlation coefficients nasal/central: month 1, 0.905; month 36, 0.806; temporal/central: month 1, 0.906; month 36, 0.806; P<0.001). Moderate negative correlations were found between the spherical equivalent power of the implanted IOL and the E–IOL distance (correlation coefficients −0.271 to −0.412, P>0.05). For an E–IOL distance of the IOL edge >1500 μm, the distance from the endothelium to the central point of the p-IOL optic should be a minimum of 1,700 μm to improve the safety profile for Artiflex p-IOL implantation and reduce the potential complication of accelerated endothelial cell loss.

Conclusion

After Artiflex IOL implantation, the mean annual reduction of the E–IOL distance was 25 μm. A negative correlation existed between the spherical equivalent power of the implanted IOL and the postoperative E–IOL distance. The minimum E–IOL distance from the center of the IOL to minimize the risk of endothelial cell loss was 1.7 mm. This distance, as is the 1.5 mm initially proposed by Baikoff, is a postoperative value. We cannot make that assumption for the preoperative evaluation, as the morphometry of the anterior chamber changes with the implant.

Light-dark changes in iris thickness and anterior chamber angle width in eyes with occludable angles

BACKGROUND

The purpose of this study was to investigate and measure light-dark changes in iris thickness (IT) and anterior chamber angle width in eyes with occludable angles and open angles by using anterior segment optical coherence tomography (AS-OCT).

METHODS

We examined 153 eyes of 153 Japanese patients with primary angle closure suspect, primary angle closure, primary angle closure glaucoma, or primary open angle glaucoma. AS-OCT was used to determine pupil diameter, IT, angle opening distance at 500 μm (AOD₅₀₀), and trabecular-iris space area at 500 μm (TISA₅₀₀) in each quadrant of the anterior chamber angle (superior, inferior, temporal, and nasal) under light and dark conditions.

RESULTS

In the angle closure cases, IT, AOD₅₀₀ and TISA₅₀₀ in the dark varied significantly among the four quadrants (P < 0.05, analysis of variance). In contrast, in the open angle cases, IT, AOD₅₀₀ and TISA₅₀₀ in the dark did not differ significantly among the four quadrants. In the angle closure cases and the open angle cases, significant negative associations were found between IT difference [IT(light)-IT(dark)] and AOD₅₀₀ difference [AOD₅₀₀(light)-AOD₅₀₀(dark)] (R = -0.411, P < 0.001 and R = -0.501, P = 0.001, respectively) and between IT difference and TISA₅₀₀ difference [TISA₅₀₀(light)-TISA₅₀₀(dark)] (R = -0.475, P < 0.001 and R = -0.462, P = 0.002, respectively).

CONCLUSION

Our results suggest that thickening of the iris root under dark conditions is related to the mechanism of primary angle closure. It is important to analyze both the angle structure and peripheral IT in each quadrant.

Artiflex Toric foldable phakic intraocular lens: short-term results of a prospective European multicenter study

PURPOSE

To evaluate the short-term efficacy, predictability, stability, and safety of the foldable Artiflex Toric phakic intraocular lens (pIOL; Ophtec) for the correction of myopia with astigmatism.

DESIGN

Prospective, nonrandomized multicenter study.

METHODS

One hundred fifteen eyes of 73 patients were implanted with an Artiflex Toric pIOL. Mean implanted spherical and cylindrical powers were -7.10 ± 2.70 diopters (D) and -2.14 ± 0.80 D, respectively. Total follow-up was 6 months. Outcome parameters included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), subjective manifest refraction (used for vector analysis), intraocular pressure, and endothelial cell density (ECD).

RESULTS

At 6 months, 99.0% of eyes had a UCVA of ≥20/40, and 81.8% of eyes were ±0.5 D of the intended refraction. In 74.5% postoperative UCVA was equal to or better than preoperative BSCVA; 2 eyes lost 2 or more lines of BSCVA postoperatively because of the development of synechiae. In 75.5% of eyes the remaining cylinder was ±0.5 D. There was a significant decrease in ECD after 3 months (4.8% ± 11.9%), with no additional decline between 3 and 6 months. There were few complications, except for the incidence of pigment and nonpigment precipitates (14.8% and 12.2%, respectively at 6 months). Mean misalignment was 0.6 ± 1.5 degrees (range 0-8).

CONCLUSIONS

The Artiflex Toric pIOL effectively and safely corrects myopia and astigmatism in the short term, with stable and predictable visual results after 6 months, when strict inclusion criteria are applied. Deposition of pigment and nonpigment precipitates on the pIOL warrants further investigation.

Foldable iris-fixated phakic intraocular lens implantation for the correction of myopia: two years of follow-up

Purpose:

To evaluate the safety, efficacy and potential risks of Artiflex foldable iris-fixated phakic intraocular lens (pIOL) implantation for the management of myopia.

Materials and Methods:

Seventy-eight eyes of 40 consecutive patients with a mean spherical refraction of –11.70 ± 3.77 diopters (D; range –5.50 to –17.5 D) were included in this prospective, noncomparative, interventional case series. Main parameters assessed were uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BSCVA), corneal topography (Orbscan II, BauchandLomb, Rochester, NY, USA), manifest and cycloplegic refractive errors, endothelial cell density (ECD) and applanation tonometry.

Results:

After 2 years, BSCVA was 20/40 or better in 82% of the eyes and UCVA was 20/40 or better in 84% of the eyes. After 1 month, 1 year, and 2 years, 51.3% (37 of 72 eyes), 58.9% (46 of 78 eyes) and 76.0% (38 of 50 eyes) of eyes gained 1 line or more of BSCVA, respectively. Compared to preoperative values, the mean endothelial cell loss was 2.6% at 1 month, 4.9% at 1 year and 7.4% at 2 years. Pigmented or non-pigmented precipitates were observed in17 eyes (21.7%) which were treated with topical corticosteroids. At the second postoperative year, pigmented precipitates persisted in nine eyes. However, this was not associated with a loss of BSCVA.

Conclusion:

The implantation of Artiflex pIOL is an effective surgical option for the management of high myopia. The most common complication observed within 2 years of follow-up was accumulation of pigmented precipitates with no effect on the final BSCVA.

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.

Anterior segment optical coherence tomography

Optical coherence tomography (OCT) is a non-contact optical signal acquisition and processing device that provides magnified, high resolution cross-sectional images of ocular tissues. Development of anterior segment OCT (AS-OCT) offers the benefits of fine resolution and noninvasive examination to investigation of anterior segment anatomy to the depth of the iris plane. This imaging device has been utilized for investigation into a myriad of corneal and anterior segment disease. Recent technological advances toward three-dimensional visualization broaden the scope of AS-OCT in ophthalmologic evaluation. The AS-OCT is a valuable imaging tool whose use in research and clinical practice will continue to expand our knowledge and management of various ophthalmic conditions.

Pediatric phakic intraocular lens surgery: review of clinical studies

PURPOSE OF REVIEW

To report on the accumulating peer-reviewed data of phakic intraocular lens (pIOL) implantation in the pediatric population. I evaluate and compare the published peer-reviewed articles for the reported efficacy and complications of phakic intraocular lens implantations in children for correction of clinically significant high refractive errors.

RECENT FINDINGS

Multiple studies have shown the relevancy and effectiveness of pIOL implantation as an alternative surgical management for highly significant pediatric ametropia in selective patients who are noncompliant with medical treatment.

SUMMARY

In the management of clinically significant severe pediatric ametropic and/or anisometropic myopia or hyperopia and in the event of nonadherence to traditional medical treatment, phakic anterior chamber IOL implantation is currently considered an effective modality of treatment. Long-term follow-up of pediatric patients following pIOL implantation is necessary. Future clinical trials should focus on children of various age groups to assess the variables of visual acuity gain or loss, stereopsis, contrast sensitivity, high-order aberrations, corneal physiology, and long-term complications to accurately and properly address the safety and efficacy of the type of and the best time for pIOL implantation in treatment and/or prevention of amblyopia in children.

Value of optical coherence tomography for anterior segment surgery

Anterior segment optical coherence tomography (AS-OCT) is an important new noncontact imaging technology that uses a 1310 nm super luminescent diode. It can be used to assess anterior chamber biometry, corneal thickness, lens thickness, and angle configuration; to visualize pathological processes; to evaluate postsurgical anatomy and posttraumatic eyes; and to image phakic intraocular lenses and intracorneal ring segments. Because it is a noncontact technique, it can also be used intraoperatively, which could be useful during trabeculectomy and after deep anterior lamellar keratoplasty to detect abnormalities in the cornea and interface. A disadvantage of AS-OCT is its inability to penetrate the iris pigment epithelium, which makes it impossible to evaluate the structures behind the iris. The most frequently used devices are time-domain AS-OCT, but new Fourier-domain OCT devices, which have faster image acquisition and higher resolution, are currently under investigation.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Pupillary Block Glaucoma After Implantation of Iris-Fixated Phakic Intraocular Lens

To report a case of pupillary block glaucoma after implantation of iris-fixated phakic intraocular lens (IF pIOL). A 43-year-old man was referred for pupillary block one day after implantation of IF pIOL. Slit-lamp examination revealed extremely shallow anterior chamber, closure of peripheral laser iridotomy and contact of iris on the peripheral of the optics of IF pIOL. The intraocular pressure (IOP) was 62 mm Hg. The iris moved forward in contact with the IF pIOL and the lens remained in the physiologic position, which made the distance between the lens and the iris wide. He underwent an uneventful peripheral surgical iridectomy and the IOP decreased to 6 mm Hg. Acute pupillary block glaucoma can occur after IF pIOL implantation due to the occlusion of aqueous flow between the IF pIOL and the iris if the peripheral iridotomy closes.

Comparison of internal anterior chamber diameter imaging modalities: 35-MHz ultrasound biomicroscopy, Visante optical coherence tomography, and Pentacam

PURPOSE

To compare the internal diameter of the anterior chamber among three different imaging modalities: 35-MHz ultrasound biomicroscopy (UBM), Visante optical coherence tomography (OCT), and Pentacam, and to compare the internal diameters with white-to-white (WTW) distance measured by Orbscan.

METHODS

The internal horizontal anterior chamber diameter was measured in 20 normal eyes using 35-MHz UBM (Optikon), Visante OCT (Carl Zeiss Meditec), and Pentacam (Oculus Inc). The mean horizontal anterior chamber diameters were compared, and the correlations between each pair of two different methods were evaluated. Horizontal WTW distance was measured by Orbscan IIz (Bausch & Lomb-Orbtek Inc) and then correlated with the measurements of internal anterior chamber diameter.

RESULTS

The mean horizontal anterior chamber diameter was 10.99+/-0.47 mm with UBM, 11.70+/-0.47 mm with OCT, and 11.86+/-0.45 mm with Pentacam. Ultrasound biomicroscopy measurements were significantly different than those of OCT and Pentacam (P<.001 for both). However, no significant difference was found between OCT and Pentacam (P=.19). Regarding the correlations between each pair of two different methods, UBM and OCT showed significant correlation (r=0.848, P<.001), but there was no significant correlation between OCT and Pentacam (r=0.403, P=.078), even though the mean values were similar. In the Bland-Altman plots, the range of agreement was 0.51 mm between OCT and UBM, and 0.99 mm between Pentacam and OCT.

CONCLUSIONS

Although the internal anterior chamber diameters measured by 35-MHz UBM were significantly smaller than those measured by Visante OCT and Pentacam, the measurements of UBM and Visante OCT showed significant correlation and good agreement with each other. Pentacam showed poor correlation with other measurements.

Effects of white-to-white diameter and anterior chamber depth on implantable collamer lens vault and visual outcome

PURPOSE

To investigate the effects of anterior chamber depth (ACD) and white-to-white (WTW) diameter on vault in eyes with implantable collamer lenses (ICL V4, STAAR Surgical AG) and to evaluate the effect of vault on visual outcomes and other biometric changes.

METHODS

Twenty-eight eyes of 16 patients who underwent ICL implantation were retrospectively reviewed. Patients were divided into two groups (A1, A2) according to preoperative ACD (> or = 3.3 mm and < 3.3 mm, respectively), two groups (B1, B2) based on WTW diameter (> or = 11.55 mm and < 11.55 mm, respectively), and two groups (C1, C2) according to the difference of ICL diameter and sulcus length (> or = 0.25 mm and < 0.25 mm, respectively). Vault, endothelial cell density, and visual performance were compared between each set of groups. Correlations of vault with WTW diameter, ACD, and diametric difference of the ICL from the sulcus were analyzed.

RESULTS

The high ACD and WTW groups showed significantly higher vaults (0.59 +/- 0.32 mm and 0.57 +/- 0.36 mm, respectively) than the low ACD and WTW groups (0.26 +/- 0.17 mm and 0.25 +/- 0.14 mm, respectively; P = .01 and .01), whereas the differences of diameter between the sulcus and ICL were not related to significant vault differences. The WTW diameter wascorrelated more closely to the vault than the ACD or sulcus diameter (r = 0.70, P < .001), whereas the vault difference did not affect visual quality or endothelial cell density.

CONCLUSIONS

A high WTW diameter or ACD is likely to render a high vault, regardless of any difference in the ICL and sulcus diameters.

[Iris-fixated intraocular lenses: reinforced monitoring]

In 1986, the concept of the claw lens was applied to correct myopia in phakic patients. Since then, progress has made iris-fixated phakic intraocular lenses (IOL) relatively safe, predictable, and effective for the correction of myopia, hyperopia, and astigmatism. All these models have undergone a series of design improvements to prevent complications. Despite having excellent refractive results, the principal risk is a potential progressive endothelial cell loss. Many authors have presented encouraging results. Phakic iris-fixated IOL surgery is a potentially reversible procedure, but the surgeon cannot rule out the possibility of complications. Therefore, long-term follow-up is mandatory.