Outcome after treatment of ametropia with implantable contact lenses

Retinal complications post posterior chamber phakic intraocular lens implantation at a tertiary eye hospital in the Eastern Province of Saudi Arabia

PURPOSE

Phakic intraocular lenses treat higher degrees of myopia not possible previously with conventional refractive surgery. The aim of this study is to report the incidence and risk factors of retinal complications after posterior chamber PIOL implantation and assess the differences in biometric parameters between patients who developed such complications versus those who did not.

METHODS

This retrospective study recruited 514 patients who underwent ICL implantation to correct myopia at a tertiary eye hospital center in the Eastern province of Saudi Arabia. Follow up period was at least one year. Medical records of the patients were reviewed to obtain the required data. Associations between respondents' characteristics and retinal complications were evaluated using the Chi-squared test.

RESULTS

The mean (SD) age was 27.7 (± 6.5) years ranging from 18 to 47. Laser treatment was performed in 14 cases (2.7%). Retinal complications occurred in six cases (1.2%). The risk of retinal complication was significantly higher among patients with high axial length (OR = 1.3, 95% CI 1.2, 1.4) and patients with high pre-spherical equivalent before ICL (OR = 1.09, 95% CI 1.03, 1.4).

CONCLUSION

Patients with higher axial length and higher pre-spherical equivalent before ICL implantation are at high risk of retinal complications.

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.

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.

Intraoperative Versus Postoperative Vault Measurement After Implantable Collamer Lens Implantation in a Large Cohort of Patients

PURPOSE

To compare intraoperative and postoperative central vault measurement after implantable Collamer lens (ICL; STAAR Surgical) implantation using optical coherence tomography (OCT).

METHODS

A total of 574 eyes of 338 consecutive patients undergoing myopic ICL implantation were evaluated (mean age of 30.8 ± 5.7 years, 117 men and 221 women). Central ICL vault was measured both intraoperatively using the microscope-integrated iOCT (Optomedical Technologies GmbH) mounted on a standard surgical microscope (HS Hi-R NEO 900A; Haag-Streit Surgical GmbH), and postoperatively using the CASIA2 swept-source OCT (Tomey GmbH) at 4 and 24 hours.

RESULTS

Mean differences between intraoperative and postoperative vault values were 11.5 ± 29.0% of the mean value 4 hours postoperatively (P < .001) and 2.7 ± 33.5% of the mean value 24 hours postoperatively (P < .001). Correlation analysis shows significant agreement between vault values obtained intraoperatively and at the two postoperative times, 4 hours (Spearman Rho = 0.850, P < .001) and 24 hours (Spearman Rho = 0.745, P < .001). In 73% of cases, postoperative vault values 4 hours after the surgery could be predicted from intraoperative vault values, and so were 56% of vault values 1 day after surgery. Significant differences in vault were found at the different times, grouping cases by ICL size (Kruskal-Wallis, P = .028 for intraoperative vault, and P < .001 for both postoperative vault times), with smaller vault values for the smaller ICL size.

CONCLUSIONS

Intraoperative determination of ICL vault using iOCT is an effective method for predicting postoperative ICL vault and minimizing postoperative vault surprises that could require surgical retouching. [J Refract Surg. 2021;37(7):477-483.].

Phakic intraocular lens implantation for the correction of hyperopia

The prevalence of myopia is much higher than hyperopia. Hence, there are relatively few studies investigating phakic intraocular lens (pIOL) implantation for the correction of hyperopia. This review aimed to summarize the available relevant literature on the efficacy and safety of pIOL implantation for the correction of hyperopia and hyperopic astigmatism. At present, two types of pIOLs are used to correct hyperopia and hyperopic astigmatism: anterior chamber iris-fixated pIOLs and posterior chamber implantable collamer lenses. Both have been found to be safe and effective. No serious events (eg, retinal or choroidal detachment, endophthalmitis) were reported in the reviewed articles. Implantation of pIOLs might be the optimal refractive surgery for the correction of high hyperopia.

Implantable collamer lens with a central hole for residual refractive error correction after corneal refractive surgery

The present study aimed to assess the visual and refractive outcomes of an implantable collamer lens with a central hole (ICL V4c) for residual refractive error correction after corneal refractive surgery in individuals with myopia. A total of 16 eyes of eight consecutive patients with myopia undergoing ICL V4c implantation after corneal refractive surgery were investigated. The uncorrected visual acuity (VA) and best-corrected VA were examined prior to surgery and at 1, 3 and 6 months after surgery. The post-operative values of the modulation transfer function (MTF) cutoff frequency, Strehl ratio (SR), objective scattering index (OSI) and Optical Quality Analysis System (OQAS) values (OVs) were quantitatively assessed using an OQAS. At 6 months after surgery, the mean uncorrected LogMAR VA was 0.06±0.10 and the values had improved in 100% of the eyes. The mean MTF cutoff frequency, SR, OSI, OV 100%, OV 20% and OV 9%, were 31.294±4.321 cycles/degree, 0.187±0.039, 1.399±0.274, 1.066±0.261, 0.748±0.287 and 0.509±0.229, respectively. In conclusion, ICL V4c implantation for the correction of residual refractive error after corneal refractive surgery appeared feasible and safe and also had an excellent optical performance. However, long-term changes in visual quality require further investigation.

A novel ophthalmic viscosurgical device-free phakic intraocular lens implantation makes myopic surgery safer

Purpose

To assess the efficacy and safety of a novel ophthalmic viscosurgical device-free (OVD-free) method for posterior chamber phakic intraocular lens (PIOL) implantation in myopic eyes.

Methods

In this retrospective cohort study, the medical records of myopic eyes that underwent PIOL (Implantable Collamer Lens, ICL) implantation for myopia correction at the Eye Hospital of Wenzhou Medical University between May 2015 and March 2017 were reviewed. A total of 49 eyes with complete data that met follow up requirements (2 h, 1 day, 1 week, 3 months postoperatively) were recruited. Based on the surgical techniques used, the eyes were divided into the OVD-free method group and the standard method group. The clinical data, including intraocular pressure (IOP), corrected distance visual acuity (CDVA) and spherical equivalent (SE), at each follow-up were collected for comparison. Endothelial cell loss and complications were also investigated.

Results

Twenty-one eyes received the standard method, and 28 eyes received the OVD-free method. A rise in IOP > 22 mmHg at 2 h was noted in 14 eyes (66.7%) in the standard group and none (0%) in the OVD-free group (p < 0.001). The rise in IOP from baseline was significantly higher at 2 h in the standard group (10.5 ± 5.2 mmHg vs. 2.2 ± 3.3 mmHg, difference: 8.3, 95% CI 5.8 to 10.8; p < 0.001). There was a significant difference in the time course of LogMAR CDVA changes between the two groups (p = 0.047). The LogMAR CDVA was significantly better in the OVD-free method group compared to the standard group at 1 day (− 0.076, 95% CI − 0.134 to − 0.018; p = 0.012), 1 week (− 0.071, 95% CI − 0.135 to − 0.007; p = 0.03), but not at 3 months (− 0.046, 95% CI − 0.107 to 0.015; p = 0.134). There was no significant difference in the time course of SE changes between the two groups (p = 0.471; p = 0.705). In the OVD-free group, mean endothelial cell loss was 4.6% at 3 months (2522 ± 281 vs. 2407 ± 226 cells/mm², difference: -115, 95% CI − 295 to 65; p = 0.187). No complications were reported in both groups except for the early IOP elevation in the standard group during the observation period.

Conclusions

The OVD-free method is safe and efficient for ICL implantation. It can be a safer method of ICL implantation compared to the standard method in that it completely eliminates ophthalmic viscoelastic devices-related complications without causing additional complications.

Optical quality after posterior chamber Phakic implantation of an intraocular Lens with a central hole (V4c implantable Collamer Lens) under different lighting conditions

Background

The current study compared optical quality before and after implantation of a posterior chamber phakic intraocular lens with a central hole [V4c implantable collamer lens (ICL)] under bright and dark lighting conditions by means of the Optical Quality Analysis System™ (OQAS; Visiometrics, Terrassa, Spain).

Methods

This prospective study involved 91 eyes of 46 consecutive high myopia patients (15 males and 31 females, average spherical equivalent − 10.50 ± 0.33D) undergoing implantation of a V4c ICL. The modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI), and predicted visual acuities (PVAs; 100, 20, and 9%), under different lighting conditions, were measured before and 1 week, 1 month, and 3 months after surgery.

Results

All optical parameters showed significant improvements, at all time points, under dark condition after surgery. We observed no significant changes in PVA 9% at 1 week (mean value 0.539, P = 0.12) or 1 month after surgery (mean value 0.573, P = 0.08) under bright condition; but all other postoperative parameters improved significantly. Comparing the two lighting conditions, the OSI decreased more under dark conditions at 1 week (P = 0.02), 1 month (P = 0.004), and 3 months (P = 0.002), but there was no significant difference in any other parameter. In addition, patients were divided into super high myopia (group S, spherical equivalent greater than − 10 D) and high myopia (group H, spherical equivalent from − 6 D to − 10 D), the group S improved significantly more than group H in all parameters, under both bright and dark conditions.

Conclusions

V4c ICL implantation improved optical quality under both bright and dark lighting conditions, and had a better ability to reduce the extent of scattering in the dark. Furthermore, group S achieved greater improvement in visual quality, which should be considered by physicians before surgery.

Intraocular pressure fluctuations in patients implanted with an implantable collamer lens (ICL V4c). Three-month follow-up

INTRODUCTION

Fluctuating elevated intraocular pressure (IOP) is one of the complications of an implantable collamer lens (ICL), and its alteration is a predictive factor for the development of glaucoma.

MATERIAL AND METHODS

A prospective, cross-sectional analytic study was conducted on patients suitable for ICL implantation. Complete clinical and biometric work-ups were performed, as well as night-time IOP curve, in supine position, with 4 determinations, in order to assess fluctuation, considering abnormal with a value higher than 5 mmHg. Patients underwent surgery with conventional technique and three months after the work-ups were repeated, including a night-time IOP curve to assess any changes in IOP fluctuations.

RESULTS

A total of 31 eyes of 16 patients were studied. Mean IOP fluctuation in the preoperative assessment was 3.35 ± 2 mmHg, whereas the postoperative mean was 3.0 ± 2.2 mmHg, with the difference not being statistically significant. Visual acuity and capacity, as well as spheric equivalent did show a statistically significant improvement. There were 6 cases of complications, which were related to a higher vault and a greater ICL size. There was no relationship between these findings and the angle grade, pigment, and the level of training of the surgeon.

CONCLUSIONS

The effect of an ICL on IOP fluctuations, has been studied for the first time, which was found to be not statistically significant. As in previous publications, the procedure was safe and reproducible, adding the fact that the level of training of the surgeon is not a determining factor in these findings.

Artiflex foldable lens for myopia correction results of 10 years of follow-up

PURPOSE

The aim of this study was to evaluate the long-term efficacy and safety of the Artiflex® lens implant and to follow the evolution of the number of corneal endothelial cells over time.

DESIGN

It was a retrospective study of an observational case series of patients who underwent surgery at "The INVISION Ophthalmic Hospital" (Almería, Spain) in 2007 and who were followed for 10 years.

METHODS

Setting: Clinical practice. Study population included 53 eyes of 30 patients who underwent an Artiflex® lens implant for the correction of myopia from -4 to -14 D. Each patient included in this study had stable myopia for at least 2 years and a contraindication for corneal refractive surgery. The efficacy index was defined as the quotient between uncorrected distance visual acuity postoperative and best-corrected distance visual acuity (BCDVA) preoperative. The safety index was calculated as the quotient between BCDVA postop and BCDVA preop.

RESULTS

The average efficacy and safety indices of the lenses implanted were 1.1 (SD 0.30) and 1.06 (SD 0.2) at 10 years of follow-up. In this period of time there has been a loss of 12% of the corneal endothelial cells. The postoperative complications were pigment dispersion in four eyes (7%) of four patients and decentration of phakic intraocular lens in two eyes (4%) of another two patients.

CONCLUSIONS

The Artiflex® foldable phakic lens could be a safe and effective long-term alternative for myopic patients in whom laser surgery was contraindicated.

Visual performance after implantation of two types of phakic foldable intraocular lenses for correction of high myopia

AIM

To compare Visian lens (model V4c) and Artiflex lens regarding quality (contrast sensitivity) and quantity (efficacy, predictability, safety and stability) of vision in correcting high myopia with recording and analysis of complications.

METHODS

The comparative prospective study included 39 eyes of 23 patients with high myopia, 19 eyes had Visian lens implantation (model V4c) and 20 eyes had Artiflex lens implantation. The inclusion criteria were high myopia (higher than 6.0 D) and stable refraction (<0.5 D change over one year). Outcomes included assessment of safety and efficacy indices, predictability, stability, contrast sensitivity and analysis of complications at postoperative 1d, 1wk and 1, 3, 6 and 12mo. Selection of the type of phakic intraocular lens for patients was based on surgeons' preferences, which was no specific selection criteria.

RESULTS

After 12mo of follow up, difference in uncorrected and corrected distant visual acuity (CDVA) between both groups was statistically insignificant (UDVA for VisianV4c and Artiflex lens were 0.33±0.2 logMAR and 0.37±0.2 logMAR respectively, P=0.59, CDVA for VisianV4c and Artiflex lens were 0.155±0.1 logMAR and 0.147± 0.1 logMAR respectively, P=0.87). The efficacy index was 1.25 for VisianV4c lens and 0.8 for Artiflex lens, 78.9% of eyes were within one diopter spherical equivalent in Visian V4c lens group compared to 70% in the Artiflex lens group. No eye lost lines of CVDA proving a good safety index for both lenses (safety index was 1.67 for VisianV4c lens and 1.34 for Artiflex lens). Difference in contrast sensitivity between both groups was statistically insignificant (P=0.15, 0.88, 0.27, 0.32 and 0.82 at five spatial frequencies).

CONCLUSION

Both Visian ICL V4c and Artiflex lenses are safe and effective with stable and predictable refraction and they have comparable contrast sensitivity outcomes with no vision threatening complications.

Safety and Efficacy of a New Phakic Posterior Chamber IOL for Correction of Myopia: 3 Years of Follow-up

PURPOSE

To evaluate the outcomes of a new posterior chamber phakic intraocular lens (IPCL; Care Group, Baroda, India) to correct myopia.

METHODS

This prospective, observational case series included 30 eyes undergoing implantation of the IPCL for high myopia (> -8.00 diopters [D]). Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, vault, endothelial cell loss, and adverse events were evaluated 3 years after implantation of the IPCL for high myopia.

RESULTS

The mean spherical equivalent decreased from -16.50 ± 5.62 D preoperatively to -0.89 ± 1.27 D at 3 years. The mean UDVA and CDVA were 0.38 ± 0.21 and 0.24 ± 0.09 logMAR. No eye lost any lines and 49% of eyes gained one line or more of CDVA. One eye (3.3%) developed anterior subcapsular cataract, but did not require cataract surgery at 3 years of follow-up. Two eyes (6.6%) developed a mild transient increase in intraocular pressure, which required topical medication only for 3 months. The percentage of endothelial cell loss at 3 years was 9.73% ± 6.72%. The IPCL vault tended to reduce with time, from a mean of 626.66 ± 188.98 μm at 1 month to 540.22 ± 210.76 μm at 3 years. No vision-threatening complications occurred.

CONCLUSIONS

Implantation of the new posterior chamber phakic IOL is an effective alternative to correct high myopia, showing good outcomes at 3 years. [J Refract Surg. 2018;34(12):817-823.].

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 of Visian toric collamer lens and toric acrylic intraocular lens implantation for the treatment of myopia with astigmatism

Purpose

To compare the efficacy and outcome of phakic toric implantable collamer lens (TICL) and refractive clear lens extraction with AcrySof Toric intraocular lens (TIOL) implantation for the treatment of myopic astigmatism.

Patients and methods

This study assessed eyes with myopic astigmatism >−1 D and ≤−4 D with a spherical equivalent >10 D or <10 D if the patients were unsuitable for corneal refractive surgery. These eyes were divided into group A, in which Visian Toric ICL™ Phakic TICL was implanted, and group B, which involved clear lens extraction with implantation of an AcrySof IQ toric SN60T3-9™ IOL. The outcome and complications were evaluated.

Results

This study enrolled 63 eyes of 38 patients with a follow-up period of at least 6 months. The mean postoperative spherical equivalent was −0.19±0.31 D in group A and −0.21±0.28 D in group B (P=0.69). The mean postoperative cylinder value was −0.46±0.53 D in group A and −0.32±0.41 D in group B (P=0.35). Postoperative cylinder was <1 D in 76.47% and 79.31% of eyes in groups A and B, respectively. The mean endothelial cell count was reduced by 4.32% in group A and by 5.32% in group B (P=0.003). The mean postoperative intraocular pressure increased insignificantly in group A (P=0.22) and reduced significantly in group B (P=0.004). The complication rate was 11.76% in group A and 6.90% in group B.

Conclusion

Both procedures showed predictable results and good visual results. However, the loss of accommodation and risk of retinal complications in the TIOL group suggest that the use of TICL for myopic astigmatism is a better choice in younger patients.

Capacity of straylight and disk halo size to diagnose cataract

PURPOSE

To examine the capacity of straylight and disk halo size to diagnose cataract.

SETTING

Faculty of Optics and Optometry, Universidad Complutense de Madrid, Spain.

DESIGN

Prospective study.

METHODS

Straylight, disk halo radius, and high-contrast corrected distance visual acuity (CDVA) measurements were compared between patients with age-related cataract and age-matched normal-sighted control subjects by calculating the area under the curve (AUC) receiver operating characteristic.

RESULTS

Measurements were made in 53 eyes of 53 patients with a mean age of 67.94 years ± 7.11 (SD) and 31 eyes of 31 controls with a mean age 66.06 ± 5.43 years. Significantly worse (P < .001) mean straylight (1.38 ± 0.24 log[s]), mean disk halo radius (2.40 ± 0.18 log minutes of arc [arcmin]), and mean CDVA (0.17 ± 0.11 logMAR) were recorded in the cataract group than in the control group (1.17 ± 0.11 log[s], 2.10 ± 0.16 log arcmin, and 0.08 ± 0.08 logMAR). Significant differences in AUCs were observed for disk halo radius (0.89 ± 0.04) versus straylight (0.77 ± 0.05) (P = .03) and disk halo radius versus CDVA (0.72 ± 0.05) (P = .001). The comparison of disk halo radius versus the discriminant function with input from CDVA and straylight (0.80 ± 0.05) was at the limit of significance only (0.091 ± 0.05, P = .051).

CONCLUSION

Although all 3 variables discriminated well between normal eyes and eyes with cataract, the disk halo radius showed the best diagnostic capacity.

FINANCIAL DISCLOSURE

Neither author has a financial or proprietary interest in any material or method mentioned.

One Year Follow-Up After Veriflex Phakic Intraocular Lenses Implantation for Correction of Myopia

Objectives:

The aim of this study was to evaluate visual and refractive outcomes after Veriflex phakic intraocular lenses (pIOL) implantation in moderately myopic eyes as well as postoperative complications.

Methods:

This prospective clinical study included 40 eyes of 26 patients which underwent implantation of Veriflex for correction of myopia from -6.00 to -14.50 diopters (D) in the Eye Clinic Svjetlost Sarajevo, from January 2011 to January 2014. Uncorrected distance visual acuity (UDVA), manifest residual spherical equivalent (MRSE), intraocular pressure (IOP), endothelial cell (EC) density were evaluated at one, three, six and 12 months. Other complications in postoperative period were evaluated. For statistical analysis SPSS for Windows and Microsoft Excel were used.

Results:

Out of 26 patients 14 had binocular and 12 monocular procedure, with mean age of 29.8±6.5 years. After 12 months mean UDVA was 0.73±0.20. Mean MRSE was -0.39±0.31D and 90% of eyes had MRSE within ±1D. EC loss was 7.18±4.33%. There was no significant change of IOP by the end of 12 months follow up period. The only intraoperative complication was hyphema and occurred in one eye. Few postoperative complications were: subclinical inflammation in three eyes (7,5%), pigment dispersion in four eyes (10%), ovalisation of papilla in 2 eyes (5%) and decentration of pIOL in 2 eyes (5%).

Conclusion:

Implantation of iris-claw phakic lenses Veriflex for treating moderately high myopia is a procedure with good visual and refractive results and few postoperative complications.

Comparison of peripheral iridectomy methods for posterior chamber phakic intraocular lens implantation in patients with brown irides

Background

We explore and compare the advantages and disadvantages of different operating methods for a peripheral iridectomy (PI) for phakic posterior chamber implantable contact lens (ICL) implantation in patients with dark-brown irides.

Methods

Forty-six patients completed this prospective comparative study. Neodymium: yttrium-aluminum-garnet (Nd:YAG) PI was performed in 15 patients (30 eyes) 2 weeks prior to surgery (YAG PI group). Surgical PI was performed in 17 patients (34 eyes) 2 weeks prior to the ICL implantation (preoperative PI group), and intraoperative PI was performed during ICL implantation in 14 patients (28 eyes) (intraoperative PI group). The postoperative recovery of visual acuity, intraoperative complications, operation duration, and patients’ visual disturbances were compared.

Results

Compared with the preoperative BCVA, the uncorrected visual acuity (UCVA) at 1 week was markedly restored in the preoperative PI group (P = 0.004). UCVA in the three groups of patients had all recovered well at 1 and 3 months after ICL implantation and were significantly better than the preoperative BCVA (all P < 0.01). In the YAG PI group, iris bleeding occurred in nine eyes (30.0 %) and 14 eyes (46.7 %) had pigment dispersion; these values were significantly higher than those in the preoperative PI group (5.9 and 14.7 %, respectively, both P = 0.01). In the intraoperative PI group, elevated high intraocular pressure occurred in four eyes (14.3 %), and eight eyes (28.6 %) had varying degrees of pigment dispersion after ICL implantation.

Conclusions

For patients with dark-brown irides, surgical PI performed 2 weeks prior to the implantation facilitated better postoperative recovery of visual acuity.

Trial registration

Current Controlled Trials ISRCTN35178162. Retrospectively registered March 4th, 2013.

Long-term clinical results of posterior chamber phakic intraocular lens implantation to correct myopia

BACKGROUND

The aim of this study was to determine whether implantable collamer lens (ICL) implantation to correct myopia is an effective and safe surgical option even after long-term follow up.

DESIGN

A retrospective observational study was carried out.

PARTICIPANTS

A total of 281 eyes of 145 myopic patients were included in the study.

METHODS

Patients underwent ICL implantation and had the follow-up period of at least 5 years (87 ± 18.9 months).

MAIN OUTCOME MEASURES

Outcome measures included uncorrected and corrected distance visual acuities, refraction for the evaluation of efficacy, safety, stability and predictability, ICL vault and adverse events.

RESULTS

The final mean logMAR uncorrected and corrected distance visual acuities were 0.02 ± 0.19 and -0.12 ± 0.13, respectively. The mean efficacy and safety indices were 1.04 ± 0.32 and 1.20 ± 0.26. The mean spherical equivalent decreased from -8.74 ± 2.27 diopter (D) to -0.58 ± 0.72 D, and there was high predictability with 69.8% and 87.2% having a postoperative refraction within 0.5 D and 1.0 D, respectively. The mean postoperative vault was changed from 2.53 ± 0.6 to 2.00 ± 0.7. Six (2.1%) eyes developed cataract, and the mean endothelial cell loss was 7.8 ± 8.3%. Increased intraocular pressure was found in two (0.7%) eyes that required the exchange of lenses with different sizes.

CONCLUSIONS

Implantable collamer lens implantation to correct myopia was an effective and safe surgery with high predictability and stability during long-term follow up. Slight myopic shift and cataract formation related with change in vault should be further evaluated.

Posterior chamber collagen copolymer phakic intraocular lens with a central hole to correct myopia: One-year follow-up

PURPOSE

To assess the predictability, stability, efficacy, and safety of a newly developed posterior chamber phakic intraocular lens (pIOL) (model V4c Visian Implantable Collamer Lens) to correct moderate to high myopia.

SETTING

Fernández-Vega Ophthalmological Institute, Oviedo, Spain.

DESIGN

Prospective case series.

METHODS

This study evaluated eyes that had implantation of the new pIOL model with a central hole for myopia correction. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, intraocular pressure (IOP), endothelial cell density, pIOL vault, and adverse events were evaluated over 12 months.

RESULTS

The study comprised 147 eyes of 80 patients. Preoperatively, the mean spherical equivalent (SE) was -8.80 diopters (D) ± 2.60 (SD). At 12 months, the mean SE was -0.14 ± 0.26 D, with 93.9% of eyes within ±0.50 D of the target and 100% of eyes within ±1.00 D. The mean UDVA and CDVA were 0.028 ± 0.055 logMAR and 0.003 ± 0.013 logMAR, respectively. The efficacy and safety indices were 1.00 and 1.04, respectively. All eyes had unchanged CDVA or gained 1 or more lines during the follow-up. The IOP remained stable over time; no eye developed anterior subcapsular cataract. Twelve months postoperatively, the mean vault was 405.5 ± 184.7 μm (range 100 to 980 μm), and the mean endothelial cell loss was 1.7%.

CONCLUSION

The good refractive and visual acuity outcomes and the highly stable IOP values obtained over 12 months support the use of the new pIOL model with a central hole for the correction of moderate to high myopia.

FINANCIAL DISCLOSURE

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

Five-year functional outcomes and vault of -20 diopter myopic phakic intraocular lens implantation

PURPOSE

To evaluate refractive and visual outcomes and complications associated with phakic intraocular lens (pIOL) implantation to correct high myopia.

SETTINGS

Fernández-Vega Ophthalmological Institute, Oviedo, Spain.

DESIGN

Retrospective observational case series.

METHODS

Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), refraction, vault, and adverse effects were evaluated after 5 years with Visian ICMV4 pIOL.

RESULTS

Mean spherical equivalent (SE) dropped from -18.32 ± 2.37 diopters (D) preoperatively to -0.88 ± 0.52D 5 years postoperatively; 61% of eyes were within ±0.75 D of the target. The mean Snellen decimal CDVA and UDVA were 0.73 ± 0.23 and 0.55 ± 0.26, respectively. More than 50% of eyes achieved 20/25 or better CDVA postoperatively. Four eyes had lost 2 or 1 lines of CDVA, 10 eyes had not lost any lines from preoperatively, and 46 eyes had gained 1 or more lines of CDVA 5 years postoperatively. The safety index was 1.26 ± 0.32. Forty eyes had UDVA of 20/40 or better postoperatively. The efficacy index was 0.99 ± 0.42. At 5-year follow-up, the mean central vault was 475.28 ± 216.38 μm. No eyes showed central contact between the pIOL and crystalline lens. Nevertheless, 10 eyes showed peripheral contact with a central vault between 150 and 260 μm. Two eyes developed anterior subcapsular cataract, although only 1 eye required cataract surgery.

CONCLUSIONS

Predictability, safety and effective outcomes of posterior pIOL of (- were good, as well as postoperative complications over the long term. A central vault of 260 μm was enough to prevent the peripheral contact between the pIOL and crystalline lens in eyes with high myopia.

FINANCIAL DISCLOSURE

The authors have no proprietary interest in any of the materials mentioned in this article.

Effect of Myopic Defocus on Visual Acuity after Phakic Intraocular Lens Implantation and Wavefront-guided Laser in Situ Keratomileusis

This study aimed to investigate the effect of myopic defocus on visual acuity after phakic intraocular lens (IOL) implantation and wavefront-guided laser in situ keratomileusis (wfg-LASIK). Our prospective study comprised thirty eyes undergoing posterior chamber phakic IOL implantation and 30 eyes undergoing wfg-LASIK. We randomly measured visual acuity under myopic defocus after cycloplegic and non-cycloplegic correction. We also calculated the modulation transfer function by optical simulation and estimated visual acuity from Campbell &Green's retinal threshold curve. Visual acuity in the phakic IOL group was significantly better than that in the wfg-LASIK group at myopic defocus levels of 0, -1, and -2 D (p < 0.001, p < 0.001, and p = 0.02, Mann-Whitney U-test), but not at a defocus of -3 D (p = 0.30). Similar results were also obtained in a cycloplegic condition. Decimal visual acuity values at a myopic defocus of 0, -1, -2, and -3 D by optical simulation were estimated to be 1.95, 1.21, 0.97, and 0.75 in the phakic IOL group, and 1.39, 1.11, 0.94, and 0.71 in the wfg-LASIK group, respectively. From clinical and optical viewpoints, phakic IOL implantation was superior to wfg-LASIK in terms of the postoperative visual performance, even in the presence of low to moderate myopic regression.

Phakic intraocular lens explantation: causes in 240 cases

PURPOSE

To describe the main causes of explantation of phakic intraocular lenses (PIOLs) according to the anatomical site of implantation (angle supported, iris fixated, or posterior chamber).

METHODS

This multicentric, retrospective, and consecutive study sponsored by the Spanish Ministry of Health comprised a total of 240 eyes (226 patients) explanted due to PIOL complications. Clinical data of 144 angle-supported lenses, 24 iris-fixated lenses, and 72 posterior chamber lenses explanted were recorded preoperatively and postoperatively.

RESULTS

Mean age of the patients at explantation was 46.30 ± 11.84 years (range: 25 to 80 years). The mean time between implantation and explantation was 381.14 ± 293.55 weeks (range: 0.00 to 1,551.17 weeks). It was 422.33 ± 287.81 weeks for the angle-supported group, 488.03 ± 351.95 weeks for the iris-fixated group, and 234.11 ± 4,221.60 weeks for the posterior chamber group. It was 8.10 ± 5.52 years for the angle-supported group, 9.36 ± 6.75 years for the iris-fixated group, and 4.49 ± 4.25 years for the posterior chamber group. This period of time was significantly shorter in the posterior chamber group (P < .001). Overall, the main causes of explantation were cataract formation (132 eyes, 55%), endothelial cell loss (26 eyes, 10.83%), corneal decompensation (22 eyes, 9.17%), PIOL dislocation/decentration (16 eyes, 6.67%), inadequate PIOL size or power (12 eyes, 5%), and pupil ovalization (10 cases, 4.17%). Cataract development was the cause of explantation in 51.39% of angle-supported cases, 45.83% of iris-fixated cases, and 65.28% of posterior chamber cases. Endothelial cell loss was the cause of explantation in 15.97% of angle-supported PIOLs, 8.33% of iris-fixated PIOLs, and 1.39% of posterior chamber PIOLs.

CONCLUSIONS

Cataract is the main cause of PIOL explantation, especially in posterior chamber PIOLs. In the angle-supported group, endothelial cell loss was the second cause of explantation.

Factors influencing long-term regression after posterior chamber phakic intraocular lens implantation for moderate to high myopia

PURPOSE

To evaluate the factors affecting the long-term regression after posterior chamber phakic intraocular lens (Visian ICL; STAAR Surgical) implantation for myopia.

DESIGN

Retrospective observational case series.

METHODS

We retrospectively examined 60 eyes of 35 consecutive patients (age, 38.4 ± 9.3 years [mean ± standard deviation]) with myopic refractive errors of -4.00 to -15.25 diopters (D) undergoing ICL implantation. We assessed the amount of myopic regression from 1 month to 6 years after surgery. Stepwise multiple regression analysis was used to assess the factors affecting the amount of myopic regression.

RESULTS

The mean myopic regression from 1 month to 6 years after surgery was -0.33 ± 0.71 D (0.75 to -3.00 D). Explanatory variables relevant to the myopic regression were, in order of influence, patient age (partial regression coefficient B = -0.042, P < .0001) and preoperative axial length (B = -0.186, P = .013) (adjusted R(2) = 0.300). No significant correlation was seen with other clinical factors such as sex, preoperative refraction, intraocular pressure, white-to-white distance, anterior chamber depth, central corneal thickness, or mean keratometric readings.

CONCLUSIONS

Although the great majority of the variance remains unexplained, eyes of older patients and eyes with longer axial length are more predisposed to show greater myopic regression after ICL implantation. These results indicate that not only patient age but also axial length may play some role in predicting the long-term refractive outcomes of this surgical procedure.

Intraocular pressure during the early postoperative period after 100 consecutive implantations of posterior chamber phakic intraocular lenses with a central hole

PURPOSE

To study changes in intraocular pressure (IOP) during the early postoperative period in eyes having implantation of a posterior chamber phakic intraocular lens (pIOL) (Visian Implantable Collamer Lens V4c).

SETTING

Clínica Baviera, Instituto Oftalmológico Europeo, Madrid, Spain.

DESIGN

Case series.

METHODS

This retrospective review included the first consecutive eyes having implantation of a spherical or toric myopic pIOL with a central hole at Clínica Baviera from December 2011 to June 2012 by the same experienced surgeon. The IOP was evaluated preoperatively and 1 day, 1 week, and 1 month postoperatively.

RESULTS

The study comprised 100 eyes. The mean IOP changed from 14.6 mm Hg ± 3.4 (SD) (range 8 to 26 mm Hg) preoperatively to 14.5 ± 4.6 mm Hg (range 6 to 30 mm Hg) 1 day postoperatively, 14.2 ± 4.2 mm Hg (range 6 to 29 mm Hg) at 1 week, and 12.3 ± 3.4 mm Hg (range 9 to 24 mm Hg) at 1 month. No statistically significant changes were detected over time postoperatively (P>.2). No perioperative complications associated with the implantation of the pIOL were recorded. No pIOLs were explanted, no toric pIOL rotation was detected, and no pupillary block or acute angle closure was observed.

CONCLUSION

The short-term clinical data for the new pIOL model with the central hole (KS-Aquaport) suggest that it is a safe and effective means for controlling postoperative IOP.

Eight-year follow-up of posterior chamber phakic intraocular lens implantation for moderate to high myopia

PURPOSE

To assess the long-term clinical outcomes of Implantable Collamer Lens (Visian ICL; STAAR Surgical) implantation for moderate to high myopia.

DESIGN

Retrospective observational case series.

METHODS

This study evaluated 41 eyes of 41 patients with myopic refractive errors of -4.00 to -15.25 diopters (D) who underwent ICL implantation and routine postoperative examinations. Before surgery, and 1 and 6 months and 1, 4 and 8 years after surgery, we assessed the safety, efficacy, predictability, stability, and adverse events of the surgery.

RESULTS

The safety and efficacy indices were 1.13 ± 0.27 and 0.83 ± 0.36. At 8 years, 68.3% and 85.4% of the eyes were within 0.5 and 1.0 D, respectively, of the targeted correction. Manifest refraction changes of -0.32 ± 0.73 D occurred between 1 month and 8 years. The mean endothelial cell loss from preoperative levels was 6.2% at 8 years. Two eyes (4.9%) developed clinically significant symptomatic cataract during the follow-up period. Simultaneous lens extraction and phacoemulsification with IOL implantation was successfully performed in these 2 eyes.

CONCLUSIONS

According to our experience, ICL implantation was overall good in measures of safety, efficacy, predictability, and stability for the correction of moderate to high myopia during the 8-year observation period, suggesting its long-term viability as a surgical option for the treatment of such eyes.

Implantable Collamer Lens for Correction of Refractive Errors in Patients with Keratoconus following Collagen Cross-Linking: One Year Follow-up

Objective

The purpose of this study is to assess the predictability, safety, efficacy and stability of correction of refractive errors in patients with keratoconus using Visian implantable collamer lens (ICL) following collagen cross-linking.

Materials and methods

This prospective, non-comparative study evaluated 20 eyes of 14 patients with keratoconus subjected to implantation of intraocular collamer lens at least 1 year following collagen cross-linking and stable refraction. Mean preoperative myopia was −8.43 ± 5.13 Diopters (D) (–3.5 to −20.0D and mean cylinder was −2.19 ± 1.28D (0.0 to −4.5D). The preoperative spherical equivalent (SE) was −9.52 ± 5.33D (–3.75 to −21.25D). During the 12 months follow-up, uncorrected visual acuity, best corrected visual acuity, refraction, intraocular pressure and vaulting are measured.

Results

At 12 months postoperatively, 90% of eye had refractive cylinder of <1.0D with (p = 0.003) and 20 (100%) eyes was within ±0.75D of sphere at 1 year (r2 = 0.99) and (p = 0.0085). The mean postoperative BCVA in decimal was 0.498 ± 0.232, while the mean preoperative BCVA was 0.484 ± 0.285. The safety index at 12 months was 1.02. The mean postoperative UCVA in decimal was 0.498 ± 0.232 and the mean preoperative BCVA is 0.484 ± 0.29 and the efficacy index at 12 months was 1.01.

Conclusion

Implantation of Visian Intraocular collamer lens is predictable, safe and effective way to correct refractive error in patients with keratoconus following collagen cross-linking.

How to cite this article

Shuber HS. Implantable Collamer Lens for Correction of Refractive Errors in Patients with Keratoconus following Collagen Cross-Linking: One Year Follow-up. Int J Kerat Ect Cor Dis 2014;3(1):29-35.

Posterior chamber phakic intraocular lens implantation for high myopia

AIM

To evaluate the efficacy, safety and stability of posterior chamber phakic intraocular lens implantation for the correction of high myopia.

METHODS

Retrospective case review of 82 eyes (43 patients) undergoing implantable Collamer lens (ICL) placement by a single surgeon (Xiao-Wei Gao) to correct preoperative mean spherical equivalents between -9.00 diopter (D) and -23.00D. Main outcome measures included uncorrected visual acuity (UCVA), refraction, best spectacle-corrected visual acuity (BSCVA), endothelial cell density (ECD), intraocular pressure (IOP), lens transparency, postoperative uveitis. Visante anterior segment optical coherence tomography (AS-OCT) was used to measure anterior chamber depth (ACD) and the position of ICL.

RESULTS

Mean follow-up was 6.54±3.26 months (range 3-12 months). Predictability of the manifest spherical equivalent (SE) refraction to within ±1.00D was achieved in 88% of eyes and ±0.50D in 72.5% of eyes. The mean postoperative manifest SE refraction was -1.85±0.72D, with 96.34% of eyes maintaining or gaining ≥1 line(s) of BSCVA. The mean 3-month postoperative ECD decreased but had no statistically difference compared with the preoperative ECD. Of the 7 eyes (8.54%) with a mild transient increase in intraocular pressure (up to 30mmHg), none required a second surgical procedure or prolonged topical medication. There was no loss of lens transparency. Pigmented precipitates were observed in 5 eyes (6.09%). The mean preoperative ACD measured with AS-OCT was 3.28±0.14mm, three months after surgery, the mean ACD was 2.45±0.22mm. Anterior chamber depth showed a statistically significant reduction. One eye (1.22%) had ICL spontaneous rotation, 81 eyes (98.78%) of the lens remained correctly centered.

CONCLUSION

The implantation of ICL is an effective surgical option for the management of high myopia. But its long time effect and safety still need more time to prove.

Optical quality of hyperopic and myopic phakic intraocular lenses

AIMS

To assess and compare the optical quality of the myopic and hyperopic implantable collamer lens (ICL) from its wavefront aberrations for different powers and pupil diameters.

SETTINGS AND DESIGN

Prospective study.

MATERIAL AND METHODS

The wavefront aberrations of two myopic (-3 and -6 diopters (D)) and two hyperopic V4b ICLs (+3 and +6D) were measured in vitro. To assess and compare the optical quality of different powers of ICLs, we analyzed the root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration at 3- and 4.5-mm pupil. In addition, the point spread functions (PSFs) of each ICL evaluated were calculated from the wavefront aberrations at 3- and 4.5-mm pupil.

STATISTICAL ANALYSIS

A Student's t-test for unpaired data was used for comparison between myopic and hyperopic ICLs.

RESULTS

Myopic ICLs showed negative spherical aberration, in contrast hyperopic ICLs showed positive spherical aberration, which increases when the ICL power increases, due to the innate optical properties of the lens. All ICLs evaluated had negligible amounts of other aberrations. We did not find statistical significant differences in any Zernike coefficient RMS values analyzed between myopic and hyperopic ICLs at 3- and 4.5-mm pupil (P > 0.05).

CONCLUSIONS

Myopic and hyperopic ICLs provide good and comparable optical quality for low to moderate refractive error. The ICLs evaluated showed values of wavefront aberrations clinically negligible to affect the visual quality after implantation.

ICL versus Veriflex phakic IOL for treatment of moderately high myopia: randomized paired-eye comparison

PURPOSE

To compare the objective and subjective outcome of implantable collamer lenses (ICLs; Staar Surgical, Monrovia, CA) versus Veriflex lenses (AMO, Santa Ana, CA) for the correction of moderately high myopia.

METHODS

A prospective randomized comparative eye study was performed on 24 patients with bilateral myopia that ranged from -6 to -14.5 diopters (D). One eye was implanted with an ICL and the other eye was implanted with a Veriflex phakic intraocular lens (PIOL). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), higher-order aberrations (HOAs), contrast sensitivity, patient satisfaction, central endothelial cell count, and PIOL centration were determined 6 months after surgery

RESULTS

The logMAR UDVA and CDVA improved significantly in both groups (P < .001). There was no statistically significant difference in postoperative logMAR UDVA (P = .41) or logMAR CDVA (P = .36) between the two groups. Postoperative deviation from target refraction was -0.06 ± 0.41 D in the ICL group and -0.07 ± 0.49 D in the Veriflex group (P = .15). The difference in both induced and absolute postoperative HOAs between groups was not statistically significant. The area under the log contrast sensitivity function increased significantly in both groups postoperatively. The difference in patient satisfaction between both PIOLs was not statistically significant. A higher but statistically insignificant central endothelial cell count loss occurred in the Veriflex group (P = .11).

CONCLUSION

Both ICL and Veriflex PIOLs have equally satisfactory objective and subjective visual outcomes after surgery.

Outcome of posterior chamber phakic intraocular lens procedure to correct myopia

PURPOSE

To assess the safety and efficacy of the implantable contact lens (ICL™) to treat myopia.

DESIGN

Clinical, retrospective, single center, non-randomized case series.

PARTICIPANTS

Sixty-nine eyes of 46 patients with myopia ranging from -3.00 to 25.00 D were included in this study.

INTERVENTION

Implantation of the ICL™.

MAIN OUTCOME MEASURES

Uncorrected Visual Acuity (UCVA), refraction, best spectacle corrected visual acuity (BSCVA), adverse events, operative and postoperative complications, subjective assessment and symptoms.

RESULTS

The mean follow-up was 12.35 ± 6.13 (SD) months (range, 6 months-32 months). At the last visit, 49.20% of eyes had 20/20 or better UCVA compared to preoperative 20/20 or better BSCVA of 31.9% of eyes; 69.23% of eyes had postoperative UCVA better than or equal to preoperative BSCVA. The mean manifest refractive cylinder was 1.93 ± 1.21 D at baseline and 1.00 ± 0.92 D postoperatively. The mean manifest refraction spherical equivalent (MRSE) was -11.70 ± 4.24 D preoperatively and -0.69 ± 1.13 D postoperatively. A total of 69.8% of eyes were within ±0.5 D of the predicted MRSE; 84.1% were within ±1.0 D, and 88.90% were within ±2.0 D. BSCVA of 20/20 or better was achieved in 64.6% of eyes postoperatively, compared to 31.9% preoperatively. Mean improvement in BSCVA was 1line. One eye (1.5%) lost ⩾2 lines of BSCVA at the last visit, whereas 20% of eyes improved by ⩾2 lines. A total of 56.92% of cases gained ⩾1 line of BSCVA and 4.62% of cases lost ⩾1 line. Four ICL lenses were removed without significant loss of BSCVA, and 2 eyes with clinically significant lens opacities were observed. Four eyes (5.8%) developed a pupillary block the first day postoperatively. One eye (1.4%) developed a hypotony and AC shallowing.

CONCLUSION

Implantation of ICL for the correction of myopia was a safe procedure with good visual and refractive results from the early postoperative period to 1 year. Long-term follow-up is required to confirm the long-term safety of this implant.

Comparison of optical quality and intraocular scattering after posterior chamber phakic intraocular lens with and without a central hole (Hole ICL and Conventional ICL) implantation using the double-pass instrument

Purpose

To objectively compare the optical quality and the intraocular scattering after implantation of the posterior chamber phakic implantable collamer lens (Visian ICL™, STAAR Surgical) with and without a central artificial hole for moderate to high ametropia.

Methods

This retrospective study comprised 28 eyes of 28 consecutive patients undergoing Hole ICL implantation (mean age ± standard deviation, 30.3±5.8 years), and 24 age-matched eyes of 24 patients undergoing conventional ICL implantation (age, 30.4±6.1 years). We quantitatively assessed the postoperative values of MTF cutoff frequency, Strehl ratio, objective scattering index (OSI), and OQAS values (OVs), using an Optical Quality Analysis System™. We compared these postoperative variables between the two groups.

Results

The mean MTF cutoff frequency, Strehl ratio, OSI, OV100%, OV 20%, and OV9%, were 26.21±8.32 cycles/degree, 0.16±0.04, 1.16±0.57, 0.87±0.28, 0.80±0.35, and 0.80±0.33, respectively, 3 months after Hole ICL implantation. We found no significant differences in the MTF cutoff frequency (Mann Whitney U test, p = 0.59), the Strehl ratio (p = 0.82), the OSI (p = 0.63), or the OVs at contrasts of 100% (p = 0.58), 20% (p = 0.40), and 9% (p = 0.87), between the two groups.

Conclusions

Both Hole ICL and conventional ICL implantation provides an excellent optical performance including intraocular scattering. Newly developed Hole ICL implantation appears to be essentially equivalent in the optical quality variables to conventional ICL implantation, suggesting that the presence of the central artificial hole does not significantly affect the optical quality and the intraocular scattering after surgery.

Intraindividual comparison of visual performance after posterior chamber phakic intraocular lens with and without a central hole implantation for moderate to high myopia

PURPOSE

To compare postoperative visual performance after implantable Collamer lenses with and without a central hole (Hole ICL and conventional ICL) are implanted to correct moderate to high myopia.

DESIGN

Prospective intraindividual comparative study.

PATIENTS AND METHODS

This study evaluated 58 eyes of 29 patients with spherical equivalents of -7.55 ± 2.09 diopters (D) [mean ± standard deviation] who underwent Hole ICL implantation in one eye and conventional ICL implantation in the other eye by randomization assignment. Ocular higher-order aberrations (HOAs) and contrast sensitivity (CS) function were measured by Hartmann-Shack aberrometry and a contrast sensitivity unit before and 3 months after surgery, respectively. From the contrast sensitivity, the area under the log CS function was calculated.

RESULTS

For 4-mm and 6-mm pupils, the changes after Hole ICL implantation in coma-like aberrations, spherical-like aberrations, and total HOAs are similar to those after conventional ICL implantation (P > .05, Wilcoxon signed rank test). The postoperative area under the log CS function was significantly increased after Hole ICL implantation (P < .05), and was equivalent to that after conventional ICL implantation under photopic, mesopic, or mesopic with glare conditions. Subjective symptoms such as glare or halo were also essentially equivalent after Hole ICL and conventional ICL implantation.

CONCLUSIONS

A newly developed Hole ICL implantation appears to be equivalent in the induction of HOAs and CS function to conventional ICL implantation for the correction of moderate to high myopia, suggesting its viability as a surgical option for the treatment of such eyes, because it does not require additional peripheral iridotomies and may also reduce the risk of cataract formation.

Visual performance after posterior chamber phakic intraocular lens implantation and wavefront-guided laser in situ keratomileusis for low to moderate myopia

PURPOSE

To compare postoperative visual function after implantable collamer lens (ICL) implantation and after wavefront-guided laser in situ keratomileusis (LASIK) in eyes with low to moderate myopia.

DESIGN

Retrospective observational case study.

PATIENTS AND METHODS

We investigated 30 eyes of 20 patients undergoing ICL implantation and 64 eyes of 38 patients undergoing wavefront-guided LASIK for the correction of low to moderate myopia (manifest spherical equivalent: -3.00 to -5.88 diopters [D]). Ocular higher-order aberrations (HOAs) and contrast sensitivity (CS) function were measured by Hartmann-Shack aberrometry and a contrast sensitivity unit before and 3 months after surgery, respectively. From the contrast sensitivity, the area under the log contrast sensitivity function was calculated.

RESULTS

For 4-mm and 6-mm pupils, the changes in ocular third-order aberrations, fourth-order aberrations, and total HOAs after ICL implantation were significantly less than those after wavefront-guided LASIK (P < .05, Mann-Whitney U test). The postoperative area under the log contrast sensitivity function was significantly increased after ICL implantation (P < .001), whereas, after wavefront-guided LASIK, it was not significantly changed (P = .11).

CONCLUSIONS

ICL implantation induces significantly fewer ocular HOAs than wavefront-guided LASIK. Moreover, CS was significantly improved after ICL implantation but unchanged after wavefront-guided LASIK in eyes with low to moderate myopia. Thus, even in the correction of low to moderate myopia, ICL implantation appears to be superior in visual performance to wavefront-guided LASIK, suggesting that it may be a viable surgical option for the treatment of such eyes.

Retinal detachment after phakic intraocular lens implantation in severe myopic eyes

BACKGROUND

To report the incidence, clinical presentation, and surgical outcomes of retinal detachment in highly myopic patients corrected by implantation of phakic intraocular lenses (PIOLs).

METHODS

This is a retrospective interventional non-comparative case series. A total of 530 highly myopic eyes that underwent PIOLs implantation were included in the study. All patients completed at least a 2-year follow-up after PIOL implantation. The incidence of retinal detachment (RD) and subsequent treatments were reviewed. The refractive errors, axial lengths, time between refractive surgery and RD detection, vitreoretinal findings, rate of retinal reattachment, and the pre- and postoperative best-corrected visual acuity (BCVA) were analyzed.

RESULTS

The overall incidence of RD was 1.5 % (eight eyes of seven patients) with a mean time between PIOL implantation and detachment of 23.63 ± 18.12 months (range, 2 days-51 months). Mean spherical equivalent (SE) before PIOL implantation was -17.53 ± 3.86 diopters (D) (range, -11.5D to -23.5D). Six patients underwent bilateral PIOL implantation. Five eyes were implanted with anterior chamber PIOLs and the other three received posterior chamber PIOLs. A traumatic history was presented before RD detection in four cases. Horseshoe tears, atrophic holes, or giant retinal tears were found in four (50 %), two (25 %), and two (25 %) eyes, respectively. Two eyes (25 %) underwent scleral buckling surgery, five eyes (62.5 %) underwent pars plana vitrectomy surgery, and one eye (12.5 %) underwent both procedures. Anatomical retinal attachment was achieved after first RD surgery in seven eyes. Mean BCVA after PIOL implantation and before RD was 20/40 (decimal refraction, 0.51 ± 0.31) compared to that of 20/80 (decimal refraction, 0.26 ± 0.12) after the RD surgery. Mean follow-up after RD surgery was 20.63 ± 12.93 months (range, 8-42 months).

CONCLUSIONS

The incidence of RD after PIOLs implantation is low. Its characteristics do not differ significantly from the natural history of RD in high myopic eyes. PIOL implantation for surgical correction of severe myopia does not seem to increase the risk of RD. Good visual prognosis can be obtained with early surgical intervention.

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.

Implantable collamer posterior chamber intraocular lenses: a review of potential complications

PURPOSE

To review the peer-reviewed literature reporting postoperative complications of the most recent models of Visian Implantable Collamer posterior chamber intraocular lenses (ICL, STAAR Surgical Co).

METHODS

A literature search of the PubMed database was performed to identify all articles related to ICL complications. Articles were obtained and reviewed to identify those that reported complications using the latest ICL designs.

RESULTS

Cataract was the major postoperative complication reported: 136 (5.2%) in 2592 eyes. Of those, 43.4% (n=59) were reported within 1 year, 15.4% (n=21) between 1 and 3 years, and 35.3% (n=48) ≥ 3 years after ICL implantation. Twenty-one (15.4%) cataracts were reported as surgically induced, 46 (33.8%) eyes had poor vault (<200 μm), and cataract surgery was carried out in 27.9% (n=38) of eyes. Early acute intraocular pressure increase was also reported to be relatively frequent, whereas acute pupillary block was less frequent and mostly resolved with additional iridotomies. A total of 42 ICLs were explanted due to cataract and IOP. Reported endothelial cell loss varied from 9.9% at 2 years to 3.7% 4 years postoperatively. This loss was reported to be more pronounced within the first 1 to 2 years, with stability or lower progression after that time.

CONCLUSIONS

The majority of reported complications after ICL implantation are cataract formation. The improvements in lens geometry and more accurate nomograms applied to the selection of the lens to be implanted, in addition to the surgeon's learning curve, might be factors in the decreased occurrence of postoperative complications reported currently.

Toric phakic implantable collamer lens for correction of astigmatism: 1-year outcomes

Purpose:

The purpose of this study was to assess predictability, efficacy, safety and stability in patients who received a toric implantable collamer lens to correct moderate to high myopic astigmatism.

Methods:

Forty-three eyes of 23 patients underwent implantation of a toric implantable collamer lens (STAAR Surgical Inc) for astigmatism correction. Mean spherical refraction was −4. 98 ± 3.49 diopters (D) (range: 0 to −13 D), and mean cylinder was −2.62 ± 0.97 D (range: −1.00 to −5.00 D). Main outcomes measures evaluated during a 12-month follow-up included uncorrected visual acuity (UCVA), refraction, best-corrected visual acuity (BCVA), vault, and adverse events.

Results:

At 12 months the mean Snellen decimal UCVA was 0.87 ± 0.27 and mean BCVA was 0.94 ± 0.21, with an efficacy index of 1.05. More than 60% of the eyes gained ≥1 line of BCVA (17 eyes, safety index of 1.14). The treatment was highly predictable for spherical equivalent (r² = 0.99) and astigmatic components: J₀ (r² = 0.99) and J₄₅ (r² = 0.90). The mean spherical equivalent dropped from −7.29 ± 3.4 D to −0.17 ± 0.40 D at 12 months. Of the attempted spherical equivalent, 76.7% of the eyes were within ±0.50 D and 97.7% eyes were within ±1.00 D, respectively. For J₀ and J₄₅, 97.7% and 83.7% were within ±0.50 D, respectively.

Conclusion:

The results of the present study support the safety, efficacy, and predictability of toric implantable collamer lens implantation to treat moderate to high myopic astigmatism.