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

The rate of vault changes after ICL V4c implantation and its correlation with anterior segment parameters

Purpose

To investigate the rate of vault changes after implantation of ICL V4c and the correlation with anterior segment parameters.

Methods

A total of 64 eyes were studied from the 37 myopic subjects recruited. CASIA2 was used to record the vault at 1 week, 1 month, 3 months and 6 months after the operation as well as the preoperative anterior segment parameters including pupil diameter, lens vault, anterior chamber depth, anterior chamber width, iris area (IA), iris thickness, angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle. The rates of vault change in different time intervals were compared and the correlations between the rates and anterior segment parameters were analyzed. P < 0.05 was considered statistically significant.

Results

The rate of vault decrease was -19.53 ± 111.28 μm/month between 1 week and 1 month, -19.90 ± 29.71 μm/month between 1 month and 3 months and -4.25 ± 18.10 μm/month between 3 months and 6 months; hence the rate was shown to slow down significantly from 3 months post-operation (P = 0.024). The average rate of vault changes showed a significant positive correlation with IA (R2 = 0.140, F = 4.980, P = 0.01). No significant correlation was found with other anterior segment parameters (all P > 0.05).

Conclusion

The rate of decreasing vault significantly slowed down from 3 months post-operation. A larger IA may imply a lower decreasing rate of vault change.

Phakic intraocular Lens implantation in keratoconus patients

BACKGROUND

Both the anterior chamber and posterior chamber phakic intraocular lenses (pIOLs) implantation are acceptable refractive surgical approaches in keratoconus patients with high anisometropia, contact lens intolerance, or who prefer spectacle and contact lens independent. They are beneficial for correcting anisometropia in stable keratoconus cases or following corneal procedures such as intrastromal corneal ring segments (ICRS), collagen cross-linking (CXL), and keratoplasty. They are suitable for eyes without advanced keratoconus with acceptable best-corrected distance visual acuity (BCDVA) or without highly irregular astigmatism, high comma, and higher-order aberrations (HOAs). Combined procedures for irregular astigmatism reduction and corneal regularization with either ICRS or topography/wavefront-guided transepithelial PRK (with or without CXL) can be associated in advance with pIOLs implantation to improve BCDVA in these cases.

AIM

To study and report the evidence regarding the safety and efficacy of pIOLs for KC patients' visual and refractive rehabilitation, we have analyzed the scientific evidence published within the last 10 years (from 2012 onwards).

RESULTS

No randomized controlled trials but only eleven retrospective case series and two prospective case series were identified. Satisfactory visual rehabilitation was achieved regarding uncorrected and corrected distance visual acuity (CDVA) and predictability of the refractive correction. Both types of pIOL (iris claw and posterior chamber pIOLs) offer very good results in terms of safety and efficacy with indexes close to or even exceeding 1.

CONCLUSION

pIOLs implantation is a valid refractive therapeutic approach for correcting stable keratoconus with moderate-to-high refractive errors, especially anisometropia associated with regular or mildly irregular astigmatism, and good CDVA.

Diagnostic Techniques to Increase the Safety of Phakic Intraocular Lenses

Preoperative and postoperative diagnostics play an important role in ensuring the safety of patients with phakic intraocular lenses (pIOLs). The risk of endothelial cell loss can be addressed by regularly measuring the endothelial cell density using specular microscopy and considering the endothelial cell loss rate and the endothelial reserve in accordance with the patient's age when deciding whether to explant a pIOL. The anterior chamber morphometrics, including the anterior chamber depth and the distance between the pIOL and the endothelium, measured using Scheimpflug tomography and anterior segment optical coherence tomography (AS-OCT), can help to assess the risk of the endothelial cell loss. In patients undergoing posterior chamber pIOL implantation, accurate prediction of the vault and its postoperative measurements using AS-OCT or Scheimpflug tomography are important when assessing the risk of anterior subcapsular cataract and secondary glaucoma. Novel approaches based on ultrasound biomicroscopy and AS-OCT have been proposed to increase the vault prediction accuracy and to identify eyes in which prediction errors are more likely. Careful patient selection and regular postoperative follow-up visits can reduce the complication risk and enable early intervention if a complication occurs.

Flexural and Cell Adhesion Characteristic of Phakic Implantable Lenses

Background and Objectives: In this study, we aimed to compare the physical properties of hole-implantable collamer lenses (H-ICLs) and implantable phakic contact lenses (IPCLs) and investigate their flexural and cell adhesion characteristics. Materials and Methods: Transverse compression load to achieve lens flexion and static Young's modulus were measured in H-ICLs and IPCLs using designated equipment. Load was measured both with and without restraining the optic section of the lenses. Adhesion of iHLEC-NY2 cells to the lens surfaces was examined using phase-contrast microscopy, and cell proliferation activity was evaluated using WST-8 assay. Results: The H-ICL showed a greater tendency for transverse compression load compared to IPCL, while the IPCL showed a higher Young's modulus with respect to the force exerted on the center of the anterior surface of the optic section. The joint between the optic section and haptic support in the IPCL was found to mitigate the effects of transverse compression load. Both lens types showed minimal cell adhesion. Conclusions: Our findings indicate that H-ICLs and IPCLs exhibit distinct physical properties and adhesive characteristics. The IPCL demonstrated higher Young's modulus and unique structural features, while the H-ICL required greater transverse compression load to achieve the flexion required to tuck the haptic supports into place behind the iris to fix the lens. The observed cell non-adhesive properties for both lens types are promising in terms of reducing complications related to cell adhesion. However, further investigation and long-term observation of IPCL are warranted to assess its stability and potential impact on the iris. These findings contribute to a better understanding of the performance and potential applications of H-ICLs and IPCLs in ophthalmology.

Factors leading to realignment or exchange after implantable collamer lens implantation in 10 258 eyes

PURPOSE

To evaluate the incidence, causes, and outcomes of implantable collamer lens (ICL) realignment or exchange after implantation of the EVO-ICL.

SETTING

Eye and ENT Hospital of Fudan University, China.

DESIGN

Retrospective study.

METHODS

The study included 10 258 consecutive eyes after ICL implantation. Preoperative refractive and biometric measurements were compared between eyes with and without realignment or exchange. For eyes with ICL realignment or exchange, visual and biometric outcomes were also compared before and after ICL realignment or exchange.

RESULTS

The overall incidence of ICL realignment or exchange was 0.21% 22 eyes. 12 eyes (0.12%) underwent ICL realignment by axis rotation (10 eyes) or ICL exchange (2 eyes) due to toric ICL (TICL) misalignment. After realignment, uncorrected distance visual acuity improved, and residual cylinder decreased from -1.75 ± 0.48 diopters (D) to -0.87 ± 0.59 D ( P = .01). 10 eyes (0.10%) underwent vertical rotation of ICL (3 eyes) or ICL exchange (7 eyes) due to excessive vault. After either vertical rotation or ICL exchange, vault decreased significantly ( P < .05).

CONCLUSIONS

The incidence of ICL realignment or exchange after ICL implantation is low. TICL misalignment and excessive vault are 2 main causes. Implant exchange may be performed for excessive vault or misalignment with an insufficient vault. In addition, vertical rotation of an ICL may be a less invasive method to treat excessive vault in certain cases.

Tilt and decentration of posterior and anterior iris-claw intraocular lenses: a pilot study using anterior segment optical coherence tomography

BACKGROUND

Information on the centration and tilt of iris-claw intraocular lenses (IC-IOLs) is limited. In this study, we tested the capacity of an anterior segment optical coherence tomography (AS-OCT) instrument to measure decentration and tilt of anterior and posterior IC-IOLs through an integrated software.

METHODS

The present observational, cross-sectional study was conducted at University Eye Clinic of Parma (Parma, Italy). The CASIA2 swept-source AS-OCT (Tomey Corp.) was used to measure the tilt and decentration of posterior and anterior IC-IOLs in patients implanted at least 6 months in advance. After failure with full-automation, semi-manual IOL tracing was applied. In-the-bag (IB) contralateral IOLs, when present, were measured automatically. The Bland-Altman method was used to evaluate the agreement between repeated measurements (2 images for each study eye). The amount and direction of tilt and decentration were recorded and plotted into polar charts for evaluation.

RESULTS

A total of 21 patients were included: 14 with posterior and 7 with anterior IC-IOL fixation. In 17 eyes (81%), the AS-OCT provided a repeatable measurement of tilt and decentration. All contralateral eyes with IB IOL were automatically measured. The median decentration was 0.67 mm, 0.24 mm, and 0.24 mm in posterior IC-IOLs, anterior IC-IOLs, and IB IOLs group, respectively. The median tilt was 5.0°, 5.6°, and 5.6° for posterior IC-IOLs, anterior IC-IOLs, and IB IOLs, respectively. Tilt direction was mainly temporal, while decentration was inferior-temporal with posterior IC-IOLs and scattered with anterior IC-IOLs and IB IOLs.

CONCLUSIONS

The semi-manual tracing function of the CASIA2 AS-OCT provides repeatable and affordable measurements of the decentration and tilt of IC-IOLs in both the anterior and posterior chamber. Data from the former group were similar to the IB group.

Eight-year follow-up of Artiflex and Artiflex Toric phakic intraocular lens

PURPOSE

To analyse long-term efficacy, safety, visual and refractive stability and physiological changes of Artiflex Myopia and Toric phakic intraocular lenses (pIOL) separately throughout an 8-year follow-up.

DESIGN

Retrospective cohort study.

METHODS

A total of 67 eyes of 37 patients underwent Artiflex Myopia (47 eyes) or Artiflex Toric (20 eyes) implantation for correcting myopia and/or astigmatism. Follow-up evaluations were performed 1, 3, 5 and 8 years after surgery. Preoperative and postoperative data included corrected (CDVA) and uncorrected distance visual acuity (UDVA), manifest refraction, endothelial cell density (ECD) and intraocular pressure (IOP) assessments. Efficacy and safety indexes were analysed. The vectorial analysis was performed using the Thibos method.

RESULTS

Mean CDVA and UDVA of both pIOLs significantly improved from preoperative to 1 year after implantation, and then it remained stable over the 8-year follow-up. The efficacy and safety indexes after 8 years were 0.94 ± 0.16 and 1.07 ± 0.18 for Artiflex Myopia and 1.00 ± 0.11 and 1.10 ± 0.15 for Artiflex Toric, respectively. The spherical equivalent (SE) significantly improved after surgery. J0, J45 and SE refractive components showed no changes between postoperative visits. A total ECD loss of 4.8% (p < 0.001) and 10.4% (p = 0.005) was found after 8 years for Artiflex Myopia and Toric, respectively.

CONCLUSIONS

Artiflex Myopia and Toric pIOLs are a safe, efficient and predictable option for the correction of myopia and/or astigmatism. The vectorial analysis showed excellent rotation stability for the toric version.

Via pars plana anterior iris enclavation IOL fixation

AIM

To describe a via pars plana anterior iris enclavation intraocular lens (IOL) fixation technique.

METHODS

A total of 35 consecutive aphakic vitrectomised patients (average age 71.12±10.12y) underwent pars plana vitrectomy (PPV) and via pars plana anterior iris enclavation IOL fixation.

RESULTS

The mean preoperative best corrected visual acuity (BCVA) was 0.11±0.14 logMAR, the mean postoperative BCVA was 0.07±0.11 logMAR. The preoperative mean spherical equivalent was 7.22±4.21 D. The final mean spherical equivalent was -0.25±0.15 D. No eyes had hypotony, retinal or choroidal detachment or endophthalmitis.

CONCLUSION

This technique may be a safe and useful in the case of aphakia, and a prospective study would be useful to confirm this findings.

Refractive approaches to visual rehabilitation in patients with keratoconus

PURPOSE OF REVIEW

As keratoconus is a chronic disease affecting young people, vision-related quality of life is often significantly impaired in patients with this disease. However, successful management of keratoconus, including visual rehabilitation strategies, can improve quality of life in these patients. This review will describe clinical approaches that improve vision-related quality of life in patients with stable keratoconus.

RECENT FINDINGS

Several types of contact lenses including scleral lenses have been used successfully to manage keratoconus. Eyes with severe keratoconus, even those in which fitting with other types of lenses is challenging, can be successfully fitted with scleral lenses. Although laser ablative procedures, such as photorefractive keratectomy (PRK) have been traditionally contraindicated in patients diagnosed with or suspected of having keratoconus, PRK has been attempted to partially correct refractive errors in keratoconus. Although phototherapeutic keratectomy and radial keratotomy have been reported to be used in eyes with keratoconus, effectiveness and safety results have varied. Implantation of phakic intraocular lenses and intraocular lenses, including toric intraocular lenses, which primarily correct regular astigmatism, with cataract extraction or refractive lens exchange can improve vision-related quality of life in patients with keratoconus by significantly reducing cylinder while improving uncorrected visual acuity.

SUMMARY

Appropriate selection and application of treatment options based on consideration of multiple factors will help patients with keratoconus, improving their vision-related quality of life and delaying or avoiding keratoplasty.

Current Trends in Modern Visual Intraocular Lens Enhancement Surgery in Stable Keratoconus: A Synopsis of Do's, Don'ts and Pitfalls

Keratoconus is a relatively common ectatic, non-inflammatory corneal disorder that involves gradual visual deterioration through progressive alteration of the shape of the cornea. The corneal thinning, irregular astigmatism and higher order aberrations that occur as the disease progresses pose major challenges in the visual rehabilitation of such patients. This paper summarizes the current literature regarding the results of visual enhancement procedures in patients with stable keratoconus treated with standalone anterior or posterior chamber phakic intraocular lens implantation and monofocal, toric or multifocal toric intraocular lens implantation following phacoemulsification for age-related cataract extraction or refractive lens exchange.

Five-year follow-up of secondary iris-claw intraocular lens implantation for the treatment of aphakia: Anterior chamber versus retropupillary implantation

BACKGROUND

Though several procedures of IOL implantation have been described (sutured scleral fixation, intra-scleral fixation, angle-supported anterior chamber, and anterior chamber or retropupillary iris-claw IOLs), there are no randomized trials which are comparing different techniques. Hence, the surgical treatment of aphakia still remains controversial and challenging. The purpose of this study was to compare the long-term efficacy and the rate of complications of anterior versus posterior Iris-claw intraocular lenses (IOL) implantation to correct for the treatment of aphakia without sufficient capsule support.

METHODS AND FINDINGS

Consecutive eyes having secondary implantation of aphakic iris-fixated IOLs with a follow-up of at least 5 years were considered. Mean correct distance visual acuity (CDVA) changes, percentage of eyes with CDVA improvement, mean corneal endothelial cell density (CECD) loss and the rate of other complications were used for statistical analysis. The study evaluated a total of 180 eyes (Group A: 87 anterior chamber iris-claw fixation, Group B: 93 retropupillary iris-claw implantation) of 180 consecutive different patients, with aphakia of various reasons. CDVA improved significantly in both groups after surgery (P<0.001, ANOVA), and was remarkably higher than baseline in both groups from first week and during the entire follow-up (P<0.001, Tukey's Honest Significant Difference). There was no statistically significant difference in CDVA between the two groups during each follow-up visits (P = NS, unpaired t-test) and in the CDVA improvement percentage between the two groups (P = 0.882, Chi-square test). No significant changes in CECD were noted after surgery in both groups (ANOVA Group A: P = 0.067, Group B: P = 0.330P). No intra-operative complications occurred in both groups. There was no statistically significant difference in the rate of complications between the two groups (P = NS, Chi-square test), except for pigment precipitates which were higher in Group A (P<0.05, Chi-square test).

CONCLUSIONS

Five-year follow-up shows that secondary implantation of aphakic IOLs is effective and safe for the correction treatment of aphakia in eyes without capsule support.

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.

Short-term fluctuation of lens corneal distance and clinical correlation with phacodonesis

BACKGROUND

To analyze the role of short-term lens-corneal distance (LCD) fluctuation in quantifying preoperative phacodonesis and predicting intraoperative zonular weakness.

METHODS

Patients were divided into control (lens without clinical phacodonesis) and study (lens with suspicious and clinical phacodonesis) groups for evaluation. Slit-lamp examination followed by IOLMaster (Carl Zeiss) for LCD assessment was performed. Five readings were taken at five time points (0 s, 15 s, 30 s, 45 s & 60 s) continuously over a minute (short term) for the LCD fluctuation calculation.

RESULTS

A total of 135 eyes (82 controls and 53 study) were assessed. Study group included 32 (60.3%) suspicious and 21 (39.6%) moderate to severe phacodonesis. There was difference between the control and study eyes (p = 0.000) in short-term LCD fluctuation. Twenty-one study eyes (39.6%) showed LCD difference > 1 mm, including 11 eyes (52.3%) with > 2 mm. There was a difference in LCD with respect to severity of phacodonesis (p = 0.000). In the study eyes, 13 eyes underwent glued IOL implantation (clinical phacodonesis - ten, suspicious phacodonesis - three), and two eyes (suspicious phacodonesis) had glued capsular hook. Thirteen eyes (clinical phacodonesis - ten, suspicious phacodonesis - three) required intraoperative vitrectomy due to vitreous ingress. Intraoperative zonular weakness in 62.5% of eyes with suspicious donesis and association (Chi-square = 0.000) of weakness with preoperative LCD fluctuation was noted.

CONCLUSIONS

Short-term lens-corneal distance fluctuation can be used as a parameter for quantifying lens stability and as an aid in assessing the intraoperative risk.

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.

Four-year Follow-up of the Changes in Anterior Segment After Phakic Collamer Lens Implantation

PURPOSE

To assess the changes and relationship in central vaulting, flare intensity, and crystalline lens thickness during a follow-up period of 4 years after implantable collamer lens (ICL) implantation in eyes with high myopia.

DESIGN

Retrospective observational study.

METHODS

Ninety-eight eyes of 50 patients were followed up with routine measurements of central vaulting, crystalline lens thickness, endothelial cell density, and aqueous flare postoperatively. Data were analyzed by repeated-measures analysis of variance. The relationship between the annual change in crystal lens thickness after surgery and age was evaluated by Pearson correlation coefficient and linear regression.

RESULTS

There was a continuous reduction in central vaulting and endothelial cell density as well as an increase in crystalline lens thickness in ICL eyes from 1 month onward to 5 years postoperatively (P < .001). Although the trend of variation during the individual visit period was accentuated, the variation turned out to be smaller between 12 and 36 months or 60 months postoperatively (P = .42, P = .65). Aqueous flare intensity increased significantly after surgery and returned to normal 1 year later. Additionally, a positive correlation between patient age and crystalline lens thickness (r = 0.617, P < .0001) was observed in eyes with ICL implantation.

CONCLUSIONS

The changes in central vaulting, endothelial cell density, and crystalline lens thickness are more prominent during the first year after ICL implantation, tending to be relatively stable afterwards. The anterior inflammation during the early postoperative period synchronizes with the sharp progression of crystalline lens changes within the first year.

Comparison Over Time of Vault in Chinese Eyes Receiving Implantable Contact Lenses With or Without a Central Hole

PURPOSE

To compare the longitudinal vault changes after implantation of a posterior chamber phakic intraocular lens (pIOL) (Visian implantable contact lens) with (ICL V4c) and without (ICL V4) a central artificial hole for moderate to high myopia in Chinese eyes.

DESIGN

Retrospective case series.

METHODS

This study comprised 78 eyes implanted with the ICL V4c model and 82 eyes implanted with the ICL V4 model at our department by the same surgeon. The time course of the postoperative pIOL vault changes was quantitatively assessed using ultrasound biomicroscopy over 6 months.

RESULTS

There was a trend toward a decrease in all measures of central vault, peripheral vault, and the endothelium-anterior pIOL distance for both central hole pIOL and conventional pIOL over time, although the variance was not statistically significant (all P > .05). There were no significant between-group differences in the amount of the pIOL central vault, peripheral vault, or the endothelium-anterior pIOL distance at any time point after surgery (all P > .05).

CONCLUSIONS

The time course of the central hole pIOL vault changes is essentially equivalent to that of the conventional pIOL vault, suggesting that the presence of the central hole did not significantly affect the pIOL position.

Long-term ultrasound biomicroscopy observation of position changes of a copolymer posterior chamber phakic intraocular lens

PURPOSE

To evaluate longitudinal changes in Implantable Collamer Lens phakic intraocular lens (pIOL) position after implantation.

SETTING

Department of Ophthalmology, Zhejiang University, Hangzhou, China.

DESIGN

Retrospective case series.

METHODS

Myopic eyes that had pIOL implantation with a follow-up of at least 24 months were evaluated. Ultrasound biomicroscopy examinations were performed at each visit.

RESULTS

The study enrolled 62 eyes (31 patients; 22 women, 9 men) ranging in age from 21 to 46 years. The manifest spherical equivalent ranged from -8.25 to -18.75 diopters. A significant increase (mean 36 μm±50 [SD]) in the endothelium-anterior pIOL distance occurred between 1 month and 3 months (P=.000); afterward, the distance decreased slowly (P>.05). The largest decrease (mean 47±17 μm) in central vault occurred between 1 month and 3 months (P=.009). The largest decrease (mean 21±14 μm) in peripheral vault occurred between 1 month and 3 months (P=.000).

CONCLUSIONS

A significant increase in the endothelium-anterior pIOL distance occurred from 1 month to 3 months postoperatively, after which a slight decrease occurred over time. Central vault and peripheral vault had a tendency to decrease over time.

FINANCIAL DISCLOSURE

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

Iris atrophy and erosion caused by an anterior-chamber angle-supported phakic intraocular lens

We report a case in which an angle-supported phakic IOL was implanted to correct high myopia. Subsequently, the patient experienced photophobia, glare, halo, and loss of visual acuity and became concerned about the cosmetically deforming aspect of her eye. Findings included endothelial cell loss, cataract, pupil ovalization, and severe iris atrophy. The pIOL was removed and cataract surgery was performed, followed by implantation of a bag-in-the-lens IOL, but successful surgical repair of the iris was not possible because of severe iris atrophy.

FINANCIAL DISCLOSURE

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

[Scheimpflug photography for the examination of phakic intraocular lenses]

BACKGROUND

High myopia phakic intraocular lenses (IOL) have become an established means of surgical correction for high ametropia. Scheimpflug photography is one of the methods which are frequently applied for postoperative examination of the implants.

MATERIAL AND METHODS

Results from published studies employing Scheimpflug photography for examination of anterior chamber angle-fixated, iris-fixated and sulcus-fixated phakic IOLs were evaluated.

RESULTS

In several published studies Scheimpflug photography was used to examine the position of the implant and opacification of the crystalline lens. The results provided valuable evidence for the improvement of phakic IOL design.

CONCLUSION

Scheimpflug photography offers an easy to use, rapid non-contact examination of phakic IOLs.

[Possibilities for use of Scheimpflug technology in cataract surgery]

BACKGROUND

Since its first use in geography 100 years ago Scheimpflug photography has undergone much refinement making it a standard technique in anterior segment diagnostics and even surgical therapy. This review presents the perioperative applications of Scheimpflug photography in cataract and refractive lens surgery.

OBJECTIVES

Possible perioperative applications of Scheimpflug photography in cataract surgery and refractive lens surgery.

METHODS

Selective review of the literature and personal experiences.

RESULTS

In recent years there have been numerous new applications for Scheimpflug photography, with its main use in preoperative diagnostics and surgical planning. There are also useful applications for intraoperative visualization and postoperative counseling.

CONCLUSION

Multifunctional devices which enable a variety of further examinations besides Scheimpflug technology alone make the use of this technology possible and reasonable even in hospitals and practices without a focus on refractive surgery.

Scheimpflug Analysis of Centration and Bending of Posterior Chamber Phakic Intraocular Lenses

PURPOSE

The aim of the study was to present a novel technique for the assessment of postoperative centration and bending in phakic intraocular lens (PIOL), illustrated through 4 patient examples.

DESIGN

This was a prospective observational study.

METHODS

Four patients (7 eyes) who presented with complaints of reduced quality of vision after implantation with a Staar Collamer plate haptic PIOL were recruited for assessment. Scheimpflug images were obtained and analyzed with respect to the apical axis and the crystalline lens by means of an in-house-developed algorithm. The program provides an estimate for the PIOL centration and bending through an analysis of the distance between the PIOL and the crystalline lens.

RESULTS

The algorithm detected PIOL bending in 5 of the 7 eyes and PIOL decentration in 3 eyes. The PIOL bending or decentration detected corresponded, in all cases, with the axis of the astigmatism-like complaints in the patient. In 2 eyes of the same patient, the analysis could not be performed because the distance between PIOL and crystalline lens was too short for reliable analysis.

CONCLUSIONS

This algorithm is a useful tool to objectively assess the postoperative complaints of patients implanted with a posterior chamber PIOL. Bending and decentration due to anatomical variations of the sulcus lens position can be measured and in many cases correlated with patients' complaints.

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.

Pseudophacomorphic Glaucoma along with Pupillary Block after Visian™ Implantable Collamer Lens Implantation for High Myopia

PURPOSE

To report a case of bilateral glaucoma related to pseudophacomorphic mechanism in one eye and pupillary block in the other eye after Visian Implantable Collamer Lens (ICL, STAAR Surgical) insertion.

METHODS

A 44 year-old female with high myopia underwent bilateral ICL implantation of MICL12.6 after sulcus diameter measurements were performed by Pentacam.

RESULTS

Pseudophacomorphic glaucoma-related angle closure occurred due to lens oversizing in the right eye. The mechanism was relieved via ICL explantation. In the left eye, pupillary block developed in a subacute manner after closure of the peripheral iridotomy (PI). The attack was ameliorated by reestablishing patency of the iridotomy.

CONCLUSIONS

ICL-related glaucomatous attacks may result from improper sizing as well as from placement of a single PI. Identification of the proper mechanism is vital as treatments differ significantly. In pseudophacomorphic glaucoma, explantation is needed. In pupillary block glaucoma, treatment involves establishment of a patent PI.

Stability of cachet phakic intraocular lens position during 6-months follow-up

Purpose:

To evaluate the position stability of a phakic intraocular lens (Cachet pIOL; Alcon, Laboratories, Inc., Fort Worth, TX) in the anterior chamber (AC) during a 6-months follow-up.

Methods:

Thirty eyes of 16 subjects underwent a Cachet pIOL implantation for the correction of high myopia from -6.50 to -16.00 D with plano targeted refraction. The position stability of the Cachet pIOL was evaluated using an Anterior Segment-OCT (AS-OCT, Carl Zeiss AG, Oberkochen, Germany) at 1- and 6-months postoperatively. Three measurements have been taken into account: 1) the minimum distance between the anterior surface of the Cachet pIOL optic disk and the central corneal endothelium; 2) the minimum distance between the optic disk’s edges of the pIOL and the endothelium; 3) the minimum distance between the posterior surface of the pIOL optic disk and the anterior surface of the crystalline lens. The endothelial cell density (ECD) was also recorded.

Results:

No statistically significant changes of the Cachet pIOL position in the AC were found during follow-up. The average changes were ≤0.1 mm between 1- and 6-months postoperatively (P>0.05). At the end of follow-up, The mean ECD loss was 0.7 % (from 2794 ± 337 cell/mm² to 2776 ± 388 cell/mm²; P>0.05).

Conclusion:

A high position stability of the Cachet pIOL in the anterior chamber was shown during a 6-months follow-up.

Three-year follow-up of secondary anterior iris fixation of an aphakic intraocular lens to correct aphakia

PURPOSE

To evaluate the efficacy, predictability, stability, safety, and complications of secondary anterior iris fixation of the Artisan iris-fixated intraocular lens (IOL) to correct aphakia in eyes without sufficient capsule support.

SETTING

Department of Ophthalmology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China.

DESIGN

Cohort study.

METHODS

Eyes having implantation of aphakic iris-fixated IOLs for aphakia correction were followed for 3 years.

RESULTS

The study evaluated 72 eyes (72 patients). After 3 years, the uncorrected distance visual acuity improved in all eyes (P<.05); 53 eyes (73.6%) reached 20/40 or better. Two eyes had a postoperative corrected distance visual acuity (CDVA) worse than the preoperative CDVA due to postoperative ischemic optic neuropathy and retinal detachment, respectively. The mean spherical equivalent (SE) decreased from 11.65 diopters (D) ± 1.21 (SD) to -0.58 ± 0.56 D (P<.05); the SE at the last follow-up was within ±1.00 D of the target refraction in 63 eyes (87.5%). The mean endothelial cell loss 3 years postoperatively was 9.78%. There was no significant postoperative intraocular pressure increase throughout the follow-up. Twelve patients (16.7%) reported glare and halos during night driving. Iris pigment precipitates on the IOLs occurred in 4 eyes (5.6%) 3 years postoperatively. No other serious complications occurred.

CONCLUSIONS

Three-year results indicate that secondary implantation of aphakic IOLs is effective, predictable, and safe for the correction of aphakia in eyes without capsule support. However, longer follow-up with a larger cohort is necessary to confirm these conclusions.

Toric implantable collamer lens for moderate to high myopic astigmatism: 3-year follow-up

BACKGROUND

To evaluate the 3-year clinical outcomes after toric implantable collamer lens (ICL) implantation for the management of moderate to high myopic astigmatism.

METHODS

Thirty-four eyes of 20 patients who underwent toric ICL implantation were reviewed. All eyes completed 3-year follow-up. Uncorrected (UDVA) and corrected (CDVA) distance LogMAR visual acuities, refraction, endothelial cell density (ECD), and surgical complications were evaluated. Vectorial analysis of astigmatic correction was also done.

RESULTS

A significant improvement in UDVA, CDVA, manifest spherical and cylindrical refraction was observed at 1 week and remained stable after 3 years. Twenty-six eyes (76.5%) gained lines of CDVA, and two eyes (5.9%) showed a loss of 1 line of CDVA. The spherical equivalent (SE) was within ±0.50 D of emmetropia in 18 eyes (52.9%) and within ±1.00 D in 28 eyes (82.4%). Differences between target-induced astigmatism (TIA) and surgically-induced astigmatism (SIA) were statistically significant (p < 0.01), and a trend to undercorrection of the refractive astigmatism was present after 3 years. The magnitude of flattening effect (FE) was found to be significantly lower than the magnitude of TIA (p < 0.01). The magnitude of the torque vector was always positive, with a value below 0.50 D in all cases. No vision-threatening complications were observed during the follow-up.

CONCLUSION

Toric ICL implantation is an effective and safe surgical option that provides a relatively predictable and stable refractive correction of myopic astigmatism. Further improvements are needed to minimize the degree of undercorrection.

Transient myopic shift after phakic intraocular lens implantation

Three patients presented with spontaneous myopic shift 6 weeks to 6 months after implantation of the Artiflex phakic intraocular lens (pIOL). The corrected distance visual acuity (CDVA) was maintained in all cases. Cyclopentolate drops successfully reverted the myopic shift in all cases; however, 2 cases required surgical reenclavation of the pIOL haptics to achieve long-term refractive stability. At the last follow-up, all patients had returned to emmetropia, with uncorrected distance visual acuities of 20/20. A slight decrease in objective optical quality was observed. No eye lost a line of CDVA. In 1 eye, optical coherence tomography scans showed slight posterior positioning of the pIOL. These cases show that spontaneous myopic shift is a potential complication of iris-claw pIOL implantation. That cyclopentolate drops and/or reenclavation of the haptics were effective in reverting the situation suggests a mechanical mechanism related to iris and ciliary body dynamics.

FINANCIAL DISCLOSURE

Dr. Güell is a consultant to Ophtec. No author has a financial or proprietary interest in any material or method mentioned.

Delayed presentation of traumatic dislocation of a Visian Implantable Collamer Lens

PURPOSE

To report traumatic dislocation of a Visian Implantable Collamer Lens (ICL, STAAR Surgical Co) discovered on routine examination.

METHODS

A 26-year-old man was found to have ICL subluxation into the anterior chamber with pupillary capture on routine screening examination. The patient reported being punched near the left eye 2 weeks earlier. He noted mild blurry vision, no pain, and uncorrected distance visual acuity (UDVA) was 20/30, which was decreased from his baseline of 20/20 in the affected eye.

RESULTS

Surgical repositioning was performed under pupillary dilation without complication. Postoperatively, UDVA was 20/20(-2). Persistent pigment on the ICL, slight pupillary margin peaking, and anterior chamber inflammation were noted.

CONCLUSIONS

Traumatic ICL dislocation may occur with minimal signs and symptoms. Education of patients about the necessity for examination after ocular trauma and need to wear eye protection during activities at high risk of ocular trauma are important.

Long-term evaluation of the central vault after phakic Collamer® lens (ICL) implantation using OCT

PURPOSE

The aim of this work is to evaluate the changes in the central vault after using implantable Collamer® lenses (ICL) to correct myopia.

METHODS

This cohort study included 133 eyes; mean spherical equivalent -9.47 ± 3.71 diopters (D) (range: -2.75 to -22.25 D) who underwent ICL V4 implantation. Besides a complete ophthalmologic examination, the central vaulting was measured with Visante OCT and evaluated between different periods of follow-up (1 week, 1, 3, and 6 months, and yearly postoperatively). Post-operative time ranged from 6 to 73 months.

RESULTS

Within the first 6 months, the mean central vaulting dropped from 510 ± 238 μm (range 100 to 940 μm) to 439 ± 231 μm (range 90 to 910) a significant decrease by 71 ± 58 μm (range -170 to 30 μm) (p = 0.028) with a trend to a lower reduction after this period. After 36 month from ICL implantation, this variation tends to be smaller with the majority of the eyes having a mean decrease smaller than 2 μm per month. Initial vault (Spearman Rho = -0.237, p = 0.006) was the factor more significantly associated with decrease in vault; eyes presenting a reduction in vault >100 μm had an average initial vault that was 141 μm and 184 μm higher than eyes with no change or with increase in vault over time, respectively.

CONCLUSIONS

This study shows a continuous reduction of central vault over time. The reduction is highest during the first 6 months and tends to be lower and slow down over time. The decrease of vaulting was more pronounced in eyes with larger initial vaulting.

Intraocular stability of an angle-supported phakic intraocular lens with changes in pupil diameter

PURPOSE

To use anterior segment optical coherence tomography (AS-OCT) to evaluate the stability of a recently released angle-supported phakic intraocular lens (pIOL) in the anterior segment with changes in pupil diameter.

SETTING

Keratoconus Unit, Vissum Corporation, Alicante, Spain.

METHODS

In this observational cross-sectional study of consecutive eyes with moderate to high myopia, an AcrySof Cachet pIOL was implanted with the aim of minimizing the refractive error. An analysis of the position and stability of the pIOL before and after pharmacologic pupil dilation was performed 3 months postoperatively using the Visante AS-OCT system. A measurement protocol that included several anatomic parameters was developed and applied; the parameter values before and after dilation were compared.

RESULTS

Twenty eyes of 20 patients ranging in age from 24 to 48 years old were evaluated. The anterior chamber depth increased significantly with pupil dilation (mean change 0.06 mm +/- 0.08 [SD]) (P<.01). A significant change was also observed in the distance between the center of the cornea at the endothelial plane and the anterior surface of the pIOL (mean change 0.03 +/- 0.05 mm) (P = .01). The distances between the peripheral edges of the pIOL and the corneal endothelium and the distance between the crystalline lens and the pIOL did not change significantly (P>or=.14).

CONCLUSION

The angle-supported pIOL showed excellent intraocular behavior after pupil dilation, with no shortening of the distance between the pIOL and corneal endothelium at the center or peripheral edges of the pIOL.

Three-year stability of an angle-supported foldable hydrophobic acrylic phakic intraocular lens evaluated by Scheimpflug photography

PURPOSE

To examine the postoperative positional stability of a new angle-supported, hydrophobic acrylic phakic intraocular lens (pIOL).

SETTING

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

METHODS

In this prospective nonrandomized clinical trial, eyes with moderate to high myopia had implantation of an angle-supported pIOL (AcrySof Cachet). Scheimpflug imaging was performed preoperatively and postoperatively at 1, 3, 6 to 12, and 24 to 36 months. The main outcome measures were the distance between the corneal endothelium and the IOL and between the IOL and the crystalline lens. The overall significance threshold was P = .05.

RESULTS

Twenty-one of the 26 eyes (26 patients) evaluated were included in the statistical analysis. Analysis of variance showed no statistically significant differences in absolute endothelium-IOL or IOL-crystalline lens measurements at any postoperative visit. The mean endothelium-IOL distance was 2.05 mm +/- 0.25 (SD) at 1 month and 2.15 +/- 0.29 mm at 24 to 36 months and the mean IOL-crystalline distance, 0.92 +/- 0.23 mm and 0.86 +/- 0.22 mm, respectively. A 1-way t test showed a small but significant difference compared with zero in the overall change in the endothelium-IOL distance (mean 0.08 +/- 0.16 mm) and thus in the overall calculated anterior chamber depth (mean 0.07 +/- 0.08 mm); the difference was not significant for the IOL-crystalline lens change (mean -0.05 +/- 0.13 mm).

CONCLUSION

The angle-supported foldable hydrophobic pIOL maintained adequate central clearance distances to the corneal endothelium and the natural crystalline lens over 3 years.

FINANCIAL DISCLOSURE

Neither author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.

Late-onset nontraumatic dislocation of anterior chamber phakic intraocular lens

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

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

PURPOSE

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

DESIGN

Institutional, prospective, observational case series.

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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

PURPOSE

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

SETTING

Department of Ophthalmology, Academic Hospital Maastricht, The Netherlands.

METHODS

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

RESULTS

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

CONCLUSIONS

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