Phakic intraocular lenses

Clinical Observation of Posterior-Chamber Phakic Implantable Collamer Lens V4c Implantation in Myopic Patients with Shallow Anterior Chamber Depth: A Retrospective, Consecutive Observational Study

Purpose

The reference range for the preoperative anterior chamber angle width for ICL surgery is unclear. Our objective was to assess the clinical effect and the range of anterior chamber angle width of posterior-chamber implantable collamer lens V4c (ICL V4c) implantation in patients with anterior chamber depth (ACD) < 2.8 mm.

Methods

Patients who underwent ICL V4c implantation with shallow ACD were included in this retrospective study. The patients' uncorrected and corrected distance visual acuity, angle of trabecular-iris (TIA), angle-opening distance (AOD500), trabecular-iris space area (TISA500), corneal endothelial cell density, vault, retinal nerve fiber layer thickness, intraocular pressure, visual field, and complications were analyzed.

Results

Forty-one patients (68 eyes) completed at least 12 months of follow-up (median follow-up, 30 months). The effectiveness and safety indices were 1.09 ± 0.13 and 1.04 ± 0.21, respectively. The preoperative TIA values on the nasal and temporal sides were 39.78 ± 7.68 degree (range, 25.8-65.1 degree) and 41.54 ± 8.03 degree (range, 28.5-63.00 degree). Forty-seven eyes had uncorrected distance visual acuity ≥1.0, and 55 had corrected distance visual acuity ≥1.0 at the last follow-up visit. The TIA, AOD500, and TISA500 on the nasal and temporal sides were significantly reduced compared to those before surgery (all P < 0.01); no eye had an angle closure or elevated intraocular pressure. The ICL V4c vault was 290.88 ± 153.36 μm (range, 60.0-880.0 μm). No severe complications occurred in any patient.

Conclusions

In patients with myopia with shallow ACD (2.55-2.79 mm), a preoperative TIA >25.8° is safe and effective for a relatively long time after surgery; however, an extended long-term close follow-up is needed.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Endothelial Cell Loss in Patients with Phakic Intraocular Lenses

Although the safety of phakic intraocular lenses (pIOLs) has been continuously improved over 70-years of development, high endothelial cell losses can occur even with current pIOL models. Numerous studies have demonstrated that the distance of a pIOL to the corneal endothelium plays a crucial role in the extent of endothelial cell loss. For this reason alone, higher endothelial cell loss tends to be observed with anterior chamber lenses than with posterior chamber lenses. Adequate preoperative anterior chamber depth is essential, at least for iris-fixed pIOLs, in order to ensure a safe distance from the endothelium. However, the anterior chamber becomes shallower with age and therefore it may be useful to consider patient age in the safety criteria. Although endothelial cell loss is generally low with current pIOL models, regular monitoring of the endothelial cell density remains essential due to large interindividual differences in patients with pIOLs. If the endothelial cell loss is greater than expected and the follow-up visits confirm the trend, the pIOL should be explanted without delay. The endothelial reserve should be considered on an individual basis by taking into account patient age, physiological endothelial cell loss, and loss due to further surgery. With careful indication and long-term patient care, pIOLs remain a safe treatment option.

Phakic anterior chamber intraocular lens removal with simultaneous posterior chamber phakic intraocular lens implantation and Descemet membrane endothelial keratoplasty

The purpose of this study was to describe a case and clinical course of simultaneous anterior chamber phakic intraocular lens (AC-pIOL) removal, implantation of a posterior chamber phakic intraocular implantable collamer lens (ICL), and Descemet membrane endothelial keratoplasty (DMEK). This was a case report of a 44-year-old male with a unilateral decompensated cornea from a displaced Duet-Kelman lens on his left eye that underwent pIOL extraction and implantation of a posterior chamber phakic intraocular ICL and simultaneous DMEK. After 6 months, the cornea of the left eye had regained clarity, the Descemet membrane was graft stable, and the ICL implanted was centered with good vault. Postoperative anisometropia was avoided. There was no development of cataracts or other complications. The simultaneous pIOL extraction, ICL implantation, and DMEK in our case showed good results with full restoration of anterior segment anatomy and return of transparency of the cornea. The current case shows the feasibility of the simultaneous approach instead of sequential as an alternative for patients with endothelial disease associated with AC pIOLs, restoring vision and anatomy and also avoiding postoperative anisometropia.

The influence of pupil diameter upon and subjective quality of vision following implantable collamer lens (ICL V4c) implantation: An observational study

This study aimed to assess the change in pupil size and its influence on subjective quality of vision (QoV) in subjects with implanted collamer lenses (ICLs). This retrospective study assessed 53 participants (53 eyes) implanted with ICL (V4c) and categorized them into incremental groups according to pupil diameter. Preoperative and postoperative photopic and mesopic pupil diameter, uncorrected distance visual acuity (UDVA), and QoV questionnaire scores were assessed and compared. Postoperatively, at 3 months, UDVA was -0.10 ± 0.06 logarithm of the minimum angle of resolution (LogMAR), and mean QoV for day and night was 9.34 ± 0.76 and 8.58 ± 1.29, respectively. The mean mesopic and photopic pupil diameters were 6.59 ± 0.79 mm and 4.61 ± 0.74 mm, respectively. Photopic pupil diameter negatively correlated with "QoV day" (Rs = -0.413, P = .001), positively correlated with "haloes" (Rs = 0.568*, P < .001) and "blurred vision" (Rs = 0.243, P = .04) respectively. Mesopic pupil diameter negatively correlated with "QoV night" (Rs = -0.426, P = .001), positively correlated with "haloes" (Rs = 0.624*, P < .001), "starburst" (Rs = 0.233, P = .046) and "difficulty focusing" (Rs = 0.27, P = .025), respectively. Participants had excellent VA at 3-month follow-up. Photopic and mesonic pupil diameter negatively correlated with QoV day and QoV night scores, respectively. Pupil diameter was found to have a more significant effect on visual symptoms at night, and lower QoV due to larger pupil size was more noticeable at night. Further investigation is needed to explore the importance of pupil diameter and its impact on the QoV in ICL implanted patients.

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.

Predictability of the vault after implantable collamer lens implantation using OCT and artificial intelligence in White patient eyes

PURPOSE

To compare the predicted vault using machine learning with the achieved vault using the online manufacturer's nomogram in patients undergoing posterior chamber implantation with an implantable collamer lens (ICL).

SETTING

Centro Oculistico Bresciano, Brescia, Italy, and I.R.C.C.S.-Bietti Foundation, Rome, Italy.

DESIGN

Retrospective multicenter comparison study.

METHODS

561 eyes from 300 consecutive patients who underwent ICL placement surgery were included in this study. All preoperative and postoperative measurements were obtained by anterior segment optical coherence tomography (AS-OCT; MS-39). The actual vault was quantitatively measured and compared with the predicted vault using machine learning of AS-OCT metrics.

RESULTS

A strong correlation between model predictions and achieved vaulting was detected by random forest regression (RF; R2 = 0.36), extra tree regression (ET; R2 = 0.50), and extreme gradient boosting regression ( R2 = 0.39). Conversely, a high residual difference was observed between achieved vaulting values and those predicted by the multilinear regression ( R2 = 0.33) and ridge regression ( R2 = 0.33). ET and RF regressions showed significantly lower mean absolute errors and higher percentages of eyes within ±250 μm of the intended ICL vault compared with the conventional nomogram (94%, 90%, and 72%, respectively; P < .001). ET classifiers achieved an accuracy (percentage of vault in the range of 250 to 750 μm) of up to 98%.

CONCLUSIONS

Machine learning of preoperative AS-OCT metrics achieved excellent predictability of ICL vault and size, which was significantly higher than the accuracy of the online manufacturer's nomogram, providing the surgeon with a valuable aid for predicting the ICL vault.

Vault-Correlated Efficacy and Safety of Implantable Collamer Lens V4c Implantation for Myopia in Patients with Shallow Anterior Chamber Depth

INTRODUCTION

The aim of the study was to evaluate efficacy and safety outcomes after implantation of the Visian Implantable Collamer Lens (ICL V4c) in myopia patients with shallow anterior chamber depth (ACD).

METHODS

This retrospective study followed 163 eyes of 94 patients for at least 24 months. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity, intraocular pressure (IOP), manifest refraction, vault, endothelial cell density (ECD), anterior chamber angle (ACA), anterior chamber volume, and the distance from the corneal endothelium to the central ICL (C-ICL) were measured during follow-ups. Spearman's correlation and logistic regression were used to identify variables correlated with changes in ECD and potential risk factors for ineffective outcomes, respectively.

RESULTS

All surgeries were performed safely. High IOP of 9 eyes and anterior capsular opacity of 5 eyes were observed. The last follow-up ACA had a significant difference between the high and normal IOP groups (p = 0.0003). The mean ECD and vault were 2,855.76 ± 270.82 cells/mm2 and 388.01 ± 135.28 μm at the last follow-up, respectively. The vault and C-ICL were significantly associated with ΔECD (all p < 0.05). Furthermore, the vault was most responsible for the ECD loss. Twenty-two eyes had unsatisfactory postoperative UDVA, and the low vault at the last follow-up was a significant risk factor for this ineffective outcome (p < 0.001, OR = 14.739).

CONCLUSIONS

ICL V4c implantation in patients with shallow ACD achieved stable visual outcomes. The vault is related to postoperative visual acuity and ECD loss, which needs to be paid attention during follow-up.

Posterior-Chamber Phakic Implantable Collamer Lenses with and without a Central Hole: A Comparative Study

Purpose

 This study aimed to compare the short-term outcome of implanting the Visian implantable collamer lens V4 ICL versus the Visian V4c ICL in patients with moderate and high myopia.

Patients and Methods

 This is a retrospective that was conducted on patients with moderate or high myopia who were scheduled for ICL implantation at our institution, Patients who underwent V4 ICL implantation with peripheral iridectomy were assigned to group A, and those who underwent V4c ICL implantation without peripheral iridectomy were assigned to group B. In group A, a preoperative peripheral iridectomy was performed. In group B, the patients received cycloplegic and dilating agents. The patients underwent a complete ocular examination preoperatively and during the follow-up visits that were conducted at 3, 6, and 12 months postoperatively.

Results

This study included 214 eyes from 107 patients; group A included 110 eyes, and group B included 104 eyes. Postoperatively, the UCVA and BCVA showed statistically significant improvement across the follow-up time points (p<0.001), with no significant difference between the two groups. No statistically significant difference was found between the two groups in the mean achieved correction or the residual refraction. Both groups showed a strong correlation between the target and the achieved correction, with R2 = 0.99 in the two groups. No significant difference was found between the two groups in the IOP across all time measures. However, the intraocular pressure showed a statistically significant postoperative increase in group A (p=0.004), and no significant change in group B (p=0.817). There was a downward slope in the vaults of both groups across time, with significant variation in the last follow-up measure compared to the 3-month measure in the two groups (p<0.001). No significant difference was found between the two groups across all time measures.

Conclusion

The current study adds new evidence concerning the feasibility, safety, and efficacy of ICL V4c implantation for the treatment of moderate and high myopia, with safer postoperative IOP.

Intraocular Implantable Collamer Lens with a Central Hole Implantation: Safety, Efficacy, and Patient Outcomes

This review summarizes the available literature and provides updates on the efficacy, safety, and patient outcomes of phakic intraocular lens implantation using implantable collamer lens (ICL), with a focus on newer models with a central port (EVO/EVO+ Visian Implantable Collamer Lens, STAAR Surgical Inc.). All studies included in this review were identified from the PubMed database and were reviewed for relevancy of their topic. Data on hole-ICL implantation performed between October 2018 and October 2022 in 3399 eyes showed a weighted average efficacy index of 1.03 and a weighted average safety index of 1.19 within an average follow-up of 24.7 months. The incidence of complications such as elevated intraocular pressure, cataract, and corneal endothelial cell loss was low. Moreover, both quality of vision and quality of life improved after ICL implantation, confirming the benefits of this procedure. In conclusion, ICL implantation is a promising refractive surgery alternative to laser vision correction with excellent efficacy, safety, and patient outcomes.

Efficacy and safety after posterior chamber Implantable Collamer Lens implantation according to preoperative anterior chamber depth: Short-term comparative study

PURPOSE

To compare visual, refractive, and safety outcomes of posterior chamber Implantable Collamer Lens (ICL) implantation for the correction of myopia according to the preoperative anterior chamber depth (ACD).

METHODS

Retrospective, comparative study, patients submitted to implantation of myopic posterior-chamber phakic Implantable Collamer Lens (ICL), model V4C/V5, minimum follow-up of 12 months; two groups were created: Group 1 (ACD 2.80 to 2.99 mm) and Group 2 (ACD equal to or greater than 3.00 mm). The parameters evaluated were uncorrected and corrected visual acuity, subjective refraction, efficacy and safety index, predictability, endothelial cell density, central vault, anterior chamber angle and postoperative complications. A total of 558 eyes from 298 patients were evaluated: 111 eyes (19.9%) in group 1 and 447 eyes (80.1%) in group 2.

RESULTS

At 12 months, the efficacy index was similar in both groups (p = 0.264); the safety index was higher in group 1 (p = 0.031); the mean central Vault was significantly lower in group 1 (212.8 vs 410.6 μm; p < 0.001). Respectively, 93 (83.8%) and 366 (84.1%) eyes were within ±0.50 D of targeted refraction. Anterior chamber angle significantly decreased during follow-up in both groups (p < 0.001; p < 0.001). Intraocular pressure did not change significantly (p = 0.310 and p = 0.446, respectively). There were no significant differences in endothelial cell density loss (p = 0.278) or in the rate of complications observed (p = 0.733).

CONCLUSIONS

ICL implantation is an effective and safe procedure in eyes with shallow anterior chambers, with visual and refractive results and complication rates identical to those obtained in deeper anterior chambers.

Comparison of white-to-white measurements using four devices and their determination of ICL sizing

BACKGROUND

To compare the measurements obtained from the Orbscan II, IOLMaster 700, Pentacam AXL, and Castroviejo caliper and their effects on calculating the recommended implantable collamer lens (ICL) size and postoperative vault measurements.

METHODS

This is a retrospective cross-sectional study of patients who underwent ICL surgery by a single surgeon from March 1, 2018 to July 31, 2021. Records were reviewed for the anterior chamber depth (ACD) and white-to-white (WTW) measurements obtained from the Orbscan II, IOLMaster 700, Pentacam AXL, and Castroviejo caliper (WTW only). These were used to calculate the recommended ICL size. The actual ICL size implanted, and vault measurements obtained one month postoperatively were also collected.

RESULTS

One hundred seven eyes with a mean age of 27.9 ± 7.7 years were included in the study. Mean WTW measurements were significantly different between devices (P < 0.0001), with the IOLMaster 700 having the highest value (12.14 ± 0.04 mm) and the caliper having the lowest value (11.45 ± 0.04 mm). Mean ACD measurements were the lowest in Orbscan II (3.12 ± 0.25 mm) and the highest in Pentacam AXL (3.16 ± 0.24 mm). The Pentacam AXL produced an ICL size similar to the Orbscan in 69.2% of eyes. The IOLMaster yielded an ICL measurement one size larger than Orbscan-based calculations in 64.5% of eyes. Using the Orbscan WTW and ACD, the desired vault of 0.25 to 0.75 mm and 0.25 to 1.00 mm was achieved in 70% and 91% of eyes, respectively. Substituting caliper WTW to IOLMaster 700 or Pentacam AXL WTW increases the percentage of achieving the desired vault to 80%, similar to the Orbscan.

CONCLUSIONS

The Orbscan II, IOLMaster 700, and Pentacam AXL cannot be used interchangeably for calculating ICL sizing. Combining the WTW from caliper measurement with the ACD of the IOLMaster 700 or Pentacam AXL could improve ICL sizing and achieve a higher percentage of eyes with the desired vault.

U.S. military implantable collamer lens surgical outcomes: 11-year retrospective review

PURPOSE

To examine the long-term efficacy and safety of myopic implantable collamer lens (ICL) implantation in active duty personnel of U.S. military.

SETTING

Hospital practice.

DESIGN

Retrospective longitudinal observational study.

METHODS

1485 patients (median age 25, interquartile range 22 to 29) underwent ICL surgery. Patients received a preoperative examination including uncorrected distance visual acuity (UDVA), intraocular pressure (IOP), manifest refraction measuring corrected distance visual acuity (CDVA), corneal topography and tomography, qualitative grading of perceived ectatic risk, ophthalmic biometry, and baseline endothelial cell counts (ECCs). Outcome measures included UDVA, IOP, vault size, manifest refraction, CDVA, and ECCs. The long-term follow-up data ware drawn from the U.S. military medical record system.

RESULTS

A total of 3105 eyes were evaluated. Patients received ICLs because of either abnormal topography (2111 eyes [68%]) or high myopia (994 eyes [32%]). 94 eyes (80%) maintained UDVA of 20/25 or better up to 8 years postoperatively. The rate of achieving the desired refractive correction was 97% (503 eyes) at 1 year and 90% (81 eyes) at 8 years. Stability of these outcomes was also shown by minimal change in manifest refraction. Documented mean ECC loss was 22% at postoperative year 5. The overall rate of adverse events was 1.2% (36 eyes) including visually significant cataract formation, glaucoma, retinal detachment, and traumatic incision opening. A removal or replacement rate of 4.5% (135 eyes) was observed.

CONCLUSIONS

ICL implantation was found to be effective and safe. Vault sizes decreased over time, suggesting an increased risk of cataract formation after 7 years. Further study is necessary to assess long-term clinical significance of ECC decline.

Efficacy and Safety After Toric Posterior Chamber Implantable Collamer Lens and Toric Iris-Fixated Foldable Phakic Intraocular Lens for Myopic Astigmatism

PURPOSE

To compare visual, refractive, and safety outcomes of toric posterior chamber Implantable Collamer Lens (T-ICL) (STAAR Surgical) and toric iris-fixated foldable phakic intraocular lens (IOL) (T-Artiflex; Ophtec BV) implantation for the correction of myopic astigmatism.

METHODS

This retrospective cohort study included 312 eyes of 312 patients who had phakic IOL implantation for myopic astigmatism. Two groups were defined: 205 eyes that underwent T-ICL implantation and 107 eyes that underwent T-Artiflex implantation. Safety, efficacy, and predictability outcomes were evaluated preoperatively and at 12 months postoperatively. Refractive and corneal astigmatic vector analysis were performed using the Alpins method.

RESULTS

One year postoperatively, uncorrected distance visual acuity was 0.05 ± 0.18 (T-ICL) and 0.10 ± 0.16 (T-Artiflex) logMAR, with efficacy indexes of 1.16 ± 0.27 and 1.05 ± 0.31, respectively (P < .001). Safety indexes were 1.28 ± 0.30 and 1.21 ± 0.31, respectively (P = .04). Spherical equivalent was within ±0.50 diopters (D) of emmetropia in 165 (80.5%) and 88 (82.2%) eyes, respectively. Refractive astigmatic analysis showed an index of success of 0.28 ± 0.33 (T-ICL) and 0.31 ± 0.26 (T-Artiflex) (P = .07). Surgically induced corneal astigmatism was 0.48 ± 0.74 and 0.81 ± 0.61 D, respectively (P < .001). Mean endothelial loss was 1.11% and 2.05%, respectively (P = .42). Six (2.9%) eyes in the T-ICL group and 1 (0.9%) eye in the T-Artiflex group had phakic IOL repositioning due to significant misalignment. No vision-threatening complications occurred.

CONCLUSIONS

Both the T-ICL and T-Artiflex groups showed high visual and refractive efficacy with a good safety profile for the correction of myopic astigmatism. T-ICL implantation demonstrated significantly better efficacy and safety indexes after 12 months. Vector analysis showed similar refractive astigmatic correction in both groups, but T-Artiflex implantation revealed higher surgically induced corneal astigmatism. [J Refract Surg. 2022;38(6):339-347.].

Five Years Follow-Up of Acrysof Cachet® Angle-Supported Phakic Intraocular Lens Implantation for Myopia Correction

Purpose

The Acrysof Cachet® angle-supported phakic intraocular lens (pIOL) (Alcon Laboratories, Inc., Fort Worth, TX) is designed to correct high refractive errors in human eyes. The aim of this study was to evaluate the outcome of AcrySof Cachet® angle-supported pIOL implantation with particular regard to efficacy and safety of the implant over a 60-month follow-up period.

Design

Retrospective consecutive clinical case study.

Methods

Prior to pIOL implantation, patients had a complete ophthalmologic examination including objective and subjective refraction, uncorrected visual acuity (UCVA) and corrected distance visual acuity (CDVA), endothelial cells density (ECD), slit lamp photography, optical coherence tomography (OCT), Scheimpflug digital videokeratoscopy, optical biometry, slit lamp examination, intraocular pressure (IOP) measurement, and pupillometry. Postoperatively, patients received yearly a complete eye examination.

Results

Thirty-one eyes of 16 patients were included in this study. The mean age was 36.2 ± 8.1 years. UCVA (logMAR) improved from 1.33 ± 0.20 before surgery to 0.08 ± 0.14 one year after surgery and was 0.20 ± 0.20 five years after surgery. CDVA (logMAR) improved from 0.10 ± 0.10 before surgery to 0.05 ± 0.13 one year after surgery and was 0.04 ± 0.14 five years postoperatively. The mean percentage of endothelial cells loss (ECL) was 11.51% over the first year and 15.95% five years after surgery. There were no intraoperative complications in any of the eyes.

Conclusions

Our results up to five years after implantation of the AcrySof Cachet® angle-supported pIOL demonstrated very good outcomes in all above shown measurements, including CDVA, UCVA, and ECD. However, since major endothelial cell loss may occur in some patients with this type of pIOL, regular follow-up visits are required.

Global Tendency and Frontiers of Research on Myopia From 1900 to 2020: A Bibliometrics Analysis

Background:

Myopia is one of the most common causes of vision impairment in children and adults and has become a public health priority with its growing prevalence worldwide. This study aims to identify and evaluate the global trends in myopia research of the past century and visualize the frontiers using bibliometric analysis.

Methods

The literature search was conducted on the Web of Science for myopia studies published between 1900 and 2020. Retrieved publications were analyzed in-depth by the annual publication number, prolific countries and institutions, core author and journal, and the number of citations through descriptive statistics. Collaboration networks and keywords burst were visualized by VOSviewer and CiteSpace. Myopia citation network was visualized using CitNetExplorer.

Results

In total, 11,172 publications on myopia were retrieved from 1900 to 2020, with most published by the United States. Saw SM, from the National University of Singapore, contributed the most publications and citations. Investigative Ophthalmology &amp; Visual Science was the journal with highest number of citations. Journal of Cataract and Refractive Surgery with the maximum number of publications. The top 10 cited papers mainly focused on the epidemiology of myopia. Previous research emphasized myopia-associated experimental animal models, while recent keywords include “SMILE” and “myopia control” with the stronger burst, indicating a shift of concern from etiology to therapy and coincided with the global increment of incidence. Document citation network was clustered into six groups: “prevalence and risk factors of myopia,” “surgical control of myopia,” “pathogenesis of myopia,” “optical interventions of myopia,” “myopia and glaucoma,” and “pathological myopia.”

Conclusions

Bibliometrics analysis in this study could help scholars comprehend global trends of myopia research frontiers better. Hundred years of myopia research were clustered into six groups, among which “prevalence and risk factors of myopia” and “surgical control of myopia” were the largest groups. With the increasing prevalence of myopia, interventions of myopia control are a potential research hotspot and pressing public health issue.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

PURPOSE

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

DESIGN

Single-center retrospective cohort study.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of Horizontal Corneal Diameter Measurements Using Orbscan IIz, OPD Scan III, and IOLMaster 700

PURPOSE

To compare three automated devices for measuring the horizontal corneal diameter (white to white [WTW]).

METHODS

In 65 eyes of 38 patients, the WTW distance was measured independently by three examiners using the following techniques: Orbscan IIz tomography system (Bausch & Lomb), IOLMaster 700 (Carl Zeiss Meditec), and OPD Scan III (NIDEK). We tested for systematic differences in measurements and estimated the limits of agreement (LoA) using linear mixed-effects models.

RESULTS

The mean WTW distance was 11.8±0.40 mm with Orbscan IIz, 12.1±0.5 mm with IOLMaster 700 and 12.0±0.4 mm with OPD Scan III. The mean difference between IOLMaster 700 and Orbscan IIz was 0.33 (95% CI, 0.28 to 0.38; P<0.001), between OPD Scan III and Orbscan IIz was 0.24 mm (95% CI, 0.21 to 0.28; P<0.001), and between IOL Master 700 and OPD Scan III was 0.09 (95% CI, 0.05 to 0.12; P<0.001). The 95% LoA for Orbscan IIz versus IOLMaster 700 was -0.69 to 0.03 mm, Orbscan IIz versus OPD Scan III was -0.52 to -0.03 mm, and OPD versus IOLMaster 700 was -0.39 to 0.22 mm.

CONCLUSIONS

The data suggest that these devices are not interchangeable for usual clinical practice. Adjustments based on mean differences were not enough to compensate for interinstrument discrepancy in WTW measurements.

Short-Term Efficacy and Safety of Cataract Surgery Combined with Iris-Fixated Phakic Intraocular Lens Explantation: A Multicentre Study

The purpose of this study was to evaluate the short-term efficacy and safety of cataract surgery for patients with iris-fixated phakic intraocular lenses (pIOLs). This study included 96 eyes of 91 patients. The changes in the logMAR uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), subjective spherical equivalent (SE), astigmatism, and endothelial cell density (ECD) were collected retrospectively. The intraoperative and postoperative complications also were investigated to assess the surgical safety. The preoperative UCVA and BCVA improved significantly at month 1 postoperatively, respectively (p < 0.001 for both comparisons). The efficacy and safety index at month 1 postoperatively were 1.02 ± 0.56 and 1.31 ± 0.64, respectively. The SE at month 1 postoperatively was significantly (p < 0.001) higher compared to preoperatively, whereas the subjective astigmatism did not differ significantly (p = 0.078). The ECD significantly decreased at month 1 (p < 0.001). The most common postoperative complication was intraocular pressure elevation exceeding 25 mmHg in 10.4% of eyes, which was controlled with medications in all cases until month 1 postoperatively. No intraoperative complications developed. Cataract surgeries for patients with iris-fixated pIOLs were performed safely with good visual outcomes.

In vivo optical quality of posterior-chamber phakic implantable collamer lenses with a central port

BACKGROUND

The aim of this review is to summarize the optical quality results in patients following the implantation of the V4c implantable collamer lens with a central port (ICL, STAAR Surgical Inc.).

MAIN TEXT

A literature search in several databases was carried out to identify those publications, both prospective, retrospective and/or comparative with other refractive surgery procedures, reporting optical outcomes of patients who were implanted with the V4c ICL model. A total of 17 clinical studies published between 2012 and 2021 were included in this review. A detailed analysis of the available data was performed including number of eyes, follow-up and preoperative spherical equivalent. Specifically, the review focused on several optical parameters including higher-order aberrations (HOAs), modulation transfer function (MTF) cut-off frequency and Strehl ratio. This review encompassed a total of 817 eyes measured using different optical devices based on Hartmann-Shack, retinal image quality measurement and ray-tracing technologies at different follow-ups.

CONCLUSIONS

The outcomes found in this review lead us to conclude that the ICL V4c model provides good optical quality, by means of different metrics, when implanted.

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.

Long-term efficacy and safety results after iris-fixated foldable phakic intraocular lens for myopia and astigmatism: 6-year follow-up

PURPOSE

To evaluate the long-term efficacy and safety of iris-fixated foldable phakic intraocular lenses (pIOLs) for the management of myopia and astigmatism after 6-year follow-up.

SETTING

Ophthalmology Department, Hospital Braga, Portugal.

DESIGN

Retrospective cohort study.

METHODS

Patients included underwent iris-fixated foldable Artiflex pIOL implantation between January 2010 and December 2013. Follow-up evaluations were performed 6 months postoperatively and every 12 months until 72 months. Preoperative and follow-up data on uncorrected and corrected distance visual acuity (CDVA), manifest refraction, endothelial cell density (ECD), and anterior chamber depth (ACD) were analyzed.

RESULTS

A total of 177 eyes of 98 patients with a mean age of 32.33 ± 7.13 years were analyzed. There was a statistically significant improvement in CDVA from 0.09 ± 0.02 logMAR preoperatively to 0.04 ± 0.02 logMAR (P < .0001) at 6 years postoperatively. The spherical equivalent demonstrated a statistically significant improvement from -9.50 ± 2.93 diopters (D) to -0.41 ± 0.45 D at 6 years. At 72 months, the efficacy and safety indexes were 0.94 and 1.15, respectively. A mean loss of 31.77 cells/mm2 (1.19%) was observed each year until the sixth year. The overall mean ECD loss after correction for the physiological loss was 3.02% after 6 years. No correlations were observed between the mean ECD loss and the preoperative ACD.

CONCLUSIONS

The Artiflex pIOL was a safe, effective, and a stable option to correct myopia. A mean ECD loss of 3.02% was observed over 6 years. No pIOL was explanted due to corneal decompensation.

Posterior-chamber phakic implantable collamer lenses with a central port: a review

We aimed to summarize the outcomes reported following the implantation of the V4c implantable collamer lens with a central port (ICL, STAAR Surgical Inc) for myopia correction. A literature search in PubMed, Web of Science and Scopus was carried out to identify publications reporting clinical outcomes of patients who were implanted with the V4c ICL model and had a follow‐up period of at least 6 months. A total of 35 clinical studies published between 2012 and 2020 were included in the present review. A comprehensive analysis of the available data was performed, focusing on visual and refractive outcomes at different time‐points post‐surgery. In addition, adverse events and other parameters such as endothelial cell density, intraocular pressure and vault measurements—which were evaluated in some of the studies—were also compared. This review encompassed a total of 2904 eyes. The outcomes reported in this review lead us to conclude that ICL V4c implantation for myopia correction is a safe and efficient procedure, with stable visual and refractive outcomes and low adverse event rates. The patient’s anterior segment should be thoroughly characterized, and the ICL parameters should be carefully selected so as to achieve good outcomes and avoid complications.

Comparison of Subjective and Objective Methods of Corneoscleral Limbus Identification from Anterior Segment Optical Coherence Tomography Images

SIGNIFICANCE

This study evaluates the reliability and validity of an automatic method of the external and internal limbal points identification from anterior segment optical coherence tomography (OCT) images in comparison with manual delineation.

PURPOSE

The purpose of this work was to evaluate the repeatability and precision of a previously proposed automatic method of external and internal limbal points identification and to compare them with the manual delineation by experienced clinicians in terms of limbus diameter.

METHODS

Optical coherence tomography tomograms obtained for 12 healthy volunteers without a history of eye diseases were analyzed. Fifteen OCT tomograms were captured for each patient. For all the images, the external and internal limbal points were determined using both the automatic and manual methods. The external and internal limbus diameters were used as the comparative parameter between the methods under consideration. The statistical analysis included mean, standard deviation, the Passing-Bablok regression, and the Pearson correlation coefficient.

RESULTS

A strong linear dependence between the automatic and manual methods was identified. While compared with the subjective estimates from clinicians, the automatic technique overestimated the external limbus diameter (bias equals 0.21 mm for optometrist and 0.23 mm for ophthalmologist) and slightly underestimated the internal limbus diameter (bias equals 0.13 mm for optometrist and 0.04 mm for ophthalmologist). The automatic method showed significantly better repeatability than the manual method in the case of external limbal points identification and comparably high repeatability for internal limbal points recognition.

CONCLUSIONS

Because of high precision and excellent repeatability, the automatic method of limbal points identification may be successfully used for estimation of the dynamic changes in the geometry of the anterior segment of the eye, where the large number of captured OCT images needs to be processed automatically with high precision.

Myopia

Myopia, also known as short-sightedness or near-sightedness, is a very common condition that typically starts in childhood. Severe forms of myopia (pathologic myopia) are associated with a risk of other associated ophthalmic problems. This disorder affects all populations and is reaching epidemic proportions in East Asia, although there are differences in prevalence between countries. Myopia is caused by both environmental and genetic risk factors. A range of myopia management and control strategies are available that can treat this condition, but it is clear that understanding the factors involved in delaying myopia onset and slowing its progression will be key to reducing the rapid rise in its global prevalence. To achieve this goal, improved data collection using wearable technology, in combination with collection and assessment of data on demographic, genetic and environmental risk factors and with artificial intelligence are needed. Improved public health strategies focusing on early detection or prevention combined with additional effective therapeutic interventions to limit myopia progression are also needed.

Phakic intraocular lenses: An overview

Phakic intraocular lenses (pIOLs) are a common solution for the surgical correction of high myopia and myopia in thin corneas. Global trends result in increasing rates of patients with high myopia which will result in increased rates of pIOL implantation. Three types of lenses can be distinguished: anterior chamber angle-supported, anterior chamber iris-fixated, and posterior chamber phakic IOLs. The efficacy of phakic intraocular lenses is generally very good, but pIOLs have undergone many changes over the years to improve the safety profile and decrease pIOL-related complications such as endothelial cell loss, corneal decompensation and cataract formation. This article describes the efficacy and safety profiles of the most recent pIOLs, as well as suggests gaps of knowledge that are deserve additional research to optimize the results of pIOLs.

Review of current status of refractive lens exchange and role of dysfunctional lens index as its new indication

Advances in phacodynamics and intraocular lenses (IOLs) has given second life to clear lens extraction (CLE) or refractive lens exchange (RLE) in recent years for the treatment of patients with high degrees of myopia, hyperopia, and astigmatism who are unsuitable for laser surgery. Furthermore, presbyopia treatment with RLE supplemented with multifocal or accommodating IOLs gives the dual benefit of correcting refractive errors with eliminating the need for cataract surgery. RLE should be consistent and effective for a good refractive outcome along with safety during the surgical procedure and in the postoperative period. Therefore, proper patient selection and accurate preoperative protocols for IOL power calculations and selection are important along with an appropriate choice of surgical procedure. Dysfunctional lens index is a new objective tool that helps surgeon to aid in diagnosing, counseling, and educating patients with dysfunctional clear lens. In this article, we give a brief overview about the application of RLE for individuals with presbyopia and refractive errors like myopia, hyperopia, and astigmatism who are not suitable for laser correction.

Comparison of Toric Implantable Collamer Lens and Toric Artiflex Phakic IOLs in Terms of Visual Outcome: a Paired Contralateral Eye Study

PURPOSE

This study sought to compare the postoperative visual outcomes of toric implantable collamer lens (T-ICL) with toric Artiflex (T-Artiflex) lenses.

DESIGN

Alternating treatment, contralateral eye matched clinical study.

METHODS

This study compared 82 eyes of 41 patients with T-ICL lenses in one eye and toric Artiflex implantation in the contralateral eye to correct myopic astigmatism. Safety, efficacy, predictability, astigmatic vector changes, contrast sensitivity, endothelial cell count, and possible adverse events were assessed at least 12 months postoperatively.

RESULTS

After a mean follow-up of 12 months, the safety index was mean 1.40 ± 0.70 in the T-ICL group and 1.20 ± 0.21 in the T-Artiflex group. Furthermore, their mean efficacy indexes were 1.24 ± 0.42 and 1.08 ± 0.23, respectively (P = .029). A total of 39 eyes (95%) in the T-ICL group and 41 eyes (100%) in the T-Artiflex group were within ±1.00 diopter (D) of emmetropia and 33 eyes (80%) and 34 eyes (83%) were within ±0.5 D of emmetropia, respectively. Vector analysis revealed mean index of success as large as 0.25 ± 0.22 in the T-ICL group and 0.24 ± 0.15 in the T-Artiflex group. Postoperative contrast sensitivities were equal in both groups under mesopic conditions for any given spatial frequency. There was an endothelial loss of 2.18% and 1.95% in the T-ICL and T-Artiflex groups, respectively. There were no significant complications in any of the groups.

CONCLUSIONS

Both lenses showed promising results in terms of safety, efficacy, and predictability for correction of myopic astigmatism. As shown in this paired-eye study, most outcomes were almost identical, and neither of these lenses were clinically superior to the other.

Explantation of phakic intraocular lenses: causes and outcomes

PURPOSE

To describe reasons for explantation of anterior and posterior chamber phakic intraocular lenses (pIOLs), as well as outcomes of the surgery.

METHODS

The medical files of patients who underwent pIOL explantation due to complications were reviewed. All patients were divided into three groups based on the type of explanted pIOL: anterior chamber angle-supported (AS pIOL), anterior chamber iris-fixated (IF pIOL), and posterior chamber (PC pIOL).

RESULTS

Sixty-two eyes of 41 patients were evaluated. There were 26 (41.9%), 16 (25.8%), and 20 (32.2%) eyes in the AS pIOL, IF pIOL, and PC pIOL groups, respectively. The mean interval between the implantation and removal of the pIOL (i.e., survival time) was 13.6 ± 8.1 years (range 0.01-21.22 years). The mean follow-up after the explantation was 22.5 ± 4.0 months (range 11.3-28.7 months). The main causes of explantation were cataract in the PC pIOL group (60%) and chronic endothelial cell loss in the AS pIOL group (53.8%) and IF pIOL group (56.2%). Overall, the procedure most often combined with pIOL explantation was phacoemulsification and implantation of a posterior chamber IOL (40.3%), followed by keratoplasty (9.6%). Intraoperative complications were significantly more common in the AS pIOL group than the other groups (p < 0.001).

CONCLUSIONS

Explantation of anterior chamber pIOLs due to severe endothelial cell loss and the proportion of keratoplasty was more common in patients with a relatively long survival time. Therefore, patients with pIOL implantation should be monitored regularly after surgery.

Safety and visual outcomes following Iris-claw phakic intraocular lens bilensectomy

PURPOSE

To evaluate the visual outcomes, safety, efficacy, and causes of bilensectomy for iris fixated phakic intraocular lenses (pIOLs).

METHODS

This was a two center consecutive retrospective study that included 43 eyes that underwent iris-claw pIOL bilensectomy. Patients with follow up less than 4 months were excluded from the study. Uncorrected, corrected visual acuity (UCVA, CDVA), refractive outcomes, efficacy, safety (number of eyes in which the postoperative CDVA was worse than the preoperative CDVA), endothelial cell density (ECD), causes of bilensectomy, the time between the implantation of the pIOL and bilensectomy, intra and postoperative complications were analyzed.

RESULTS

There was a statistically significant improvement in UCVA and CDVA after surgery (p = 0.001). The efficacy index was 0.7, four eyes had a postoperative CDVA worse than the preoperative CDVA. The mean spherical equivalent 1 year after bilensectomy was -0.78 ± 1.70 D. There was a statistically significant endothelial cell loss after iris claw lens bilensectomy (p = .003). Cataract development and endothelial cell loss were the only reasons for bilensectomy. The mean time between pIOL implantation and bilensectomy was 12.2 ± 5.5 years. One patient had corneal edema 8 months after surgery and one had a retinal detachment 11 months after surgery.

CONCLUSION

Bilensectomy was successful in improving UCVA and CDVA with an acceptable refractive outcome. Significant loss of ECD was found after surgery. The results recommend a larger ACD as selection criteria when choosing to implant an Artisan lens, and a close postoperative monitoring of the endothelial cell count.

Intraoperative optical coherence tomography in anterior segment surgery

Intraoperative optical coherence tomography (iOCT) enables real-time visualization of ocular structures during surgery and enhances our understanding of intraoperative dynamics. iOCT aids in decision-making during various anterior segment surgeries, and its efficacy and feasibility in anterior lamellar keratoplasty and endothelial keratoplasty is well established. The landmark DISCOVER study observed that iOCT altered the surgeon decision in 38% of cases undergoing lamellar keratoplasty and provided guidance regarding the need for secondary surgical intervention. iOCT also finds an application in phacoemulsification wherein it helps to assess corneal incisions, intralenticular pressure, and posterior capsule integrity during nuclear emulsification. iOCT aids in the visualization of angle structures during placement of tubes and shunts in glaucoma surgeries and allows precise creation of partial thickness scleral flaps. In addition, iOCT helps in establishing a diagnosis, as well as provide intraoperative guidance, in pediatric patients who are not cooperative for examination. The role of iOCT in refractive surgeries and ocular surface disorders is increasingly being evaluated. The limitations of present-day iOCT systems are related to instrument compatibility, automated tracking of the surgical field, and on-table volumetric analysis of the real-time images. Technological advances may facilitate complete integration of OCT in the surgical microscopes for all surgical procedures.

Iris-fixated phakic intraocular lens explantation

BACKGROUND/AIMS

To evaluate the visual outcomes and indication for surgery in a series of patients who underwent explantation of a phakic intraocular lens (PIOL).

METHODS

A retrospective case series of patients who underwent PIOL explantation in our institution was performed. The indication for explantation and visual and refractive outcomes were examined. The method of explantation is described.

RESULTS

Twenty-two eyes of 16 patients underwent PIOL explantation with a mean time to explantation of 7 ± 3 years (range 3-11.4). The mean age at explantation was 50.3 ± 9.3 years. Sixteen Artisan PIOLs and six Artiflex PIOLs were explanted. The indications for explanation were cataract development (17/22), endothelial cell loss (4/22) and synechiae formation (1/22). All patients with cataract underwent a combined procedure with explantation and phacoemulsification and the placement of a posterior chamber IOL. Mean corrected vision after explantation was 0.22 ± 0.10 logMAR (range 0.1-0.3 logMAR). One patient with endothelial cell loss required a Descemet's Stripping Endothelial Keratoplasty (DSEK).

CONCLUSION

Removal of PIOLs was necessitated most frequently by cataract followed by endothelial cell loss. Both explantation alone and explantation with concurrent phacoemulsification are safe procedures with good visual outcomes and will become more frequent in the future as more patients with PIOLs reach cataractous age.

Descemet Membrane Endothelial Keratoplasty for Corneal Decompensation Secondary to Phakic Intraocular Lenses

Purpose

To describe the surgical technique and clinical outcomes of bilensectomy (pIOL explant and phacoemulsification), followed by DMEK performed for bullous keratopathy secondary to pIOL.

Methods

Seven eyes of seven patients, who developed corneal decompensation after pIOL implantation, underwent bilensectomy followed by DMEK in a two-step procedure. Main outcome measures included uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), refraction, endothelial cell density (ECD) at 1, 3, 6, and 12 months, and intraoperative and postoperative complications.

Results

DMEK was performed at a mean time of 9.83 ± 8.23 months after bilensectomy. BCVA (log MAR) improved in all eyes, increasing from 1.11 ± 0.78 preoperatively to 0.54 ± 0.21, 0.28 ± 0.23, 0.21 ± 0.21, and 0.17 ± 0.17 at 1, 3, 6, and 12 months after DMEK. One year after surgery, mean spherical equivalent and cylinder were −0.70 ± 0.92 D and −1.50 ± 0.54 D, respectively. ECD decreased by 62 ± 4%, 69 ± 4%, 74 ± 4%, and 77 ± 3% at 1, 3, 6, and 12 months after DMEK. There was one case of primary graft failure and no other postoperative complications.

Conclusions

The two-step technique bilensectomy followed by DMEK is a feasible technique for the management of bullous keratopathy secondary to pIOL, providing a fast visual recovery with good visual and refractive results.

[Intraocular pressure after implantation of an ICL with aquaport : Development of intraocular pressure after implantation of an ICL (model V4c) with aquaport without iridotomy]

BACKGROUND AND OBJECTIVE

The latest version of the intraocular lens (ICL V4c) has a central hole (aquaport) that avoids a pupillary block. Due to this laser iridotomy or intraoperative surgical peripheral iridectomy are no longer required. In this study, we examined the intraocular pressure (IOP) after implantation of the ICL with aquaport, with special reference to the development of a possible pupillary block glaucoma.

MATERIAL AND METHODS

This retrospective non-randomized study included 87 eyes from 46 patients (consecutive case series). These patients had the ICL model V4c (without a laser iridotomy or peripheral iridectomy) implanted between January 2013 and October 2014. The preoperative IOP values were compared with the postoperative values 1-2 h, 1 day, 1 week and 1 month after implantation.

RESULTS

The median intraocular pressure was 14 ± 2 mm Hg before implantation of the ICL, palpatory normotensive 1-2 h after implantation, 13 ± 3 mm Hg 1 day after implantation, 15 ± 3 mm Hg 1 week after implantation and 16 ± 4 mm Hg 1 month after implantation (a slight statistically significant increase of the intraocular pressure, p < 0.05). In 2 patients there was a steroid response in both eyes with IOP reaching up to a maximum of 28 mm Hg. There were no peaks of intraocular pressure due to a pupillary block.

CONCLUSION

It is possible to implant the latest ICL V4c with a central hole (Aquaport) without a laser iridotomy or peripheral iridectomy or development of a pupillary block.

Changes in Endothelial Cell Count Up to Three Years After Implantation of Toric Implantable Collamer Lenses

PURPOSE

To determine the temporal effect of toric implantable collamer lens (TICL) implantation and location on corneal endothelial cell density (ECD) over a period of 36 months after surgery.

METHODS

ECD [number of cells per square millimeter estimated using the Specular Microscope SP-1P (Topcon Europe Medical B.V., Netherlands)] data were collected from cases deemed suitable for the TICL (VTICMO, VTICM5; STAAR Surgical, Nidau, Switzerland). The preoperative refractive error (sphere and cylinder) ranged from -1.00 to -22.25 diopter sphere and from -0.50 to -5.50 diopter cylinder. ECD was evaluated at preoperative and all postoperative sessions.

RESULTS

Key findings were as follows: the mean ECD (±SD, 95% confidence interval) was 2720 cells/mm (±272, 2620-2820 cells/mm) preoperatively, which was reduced to 2372 cells/mm (±325, 2250-2490 cells/mm) at 36 months postoperatively (P < 0.001). Linear regression revealed the following significant correlations between the (1) log of the change in ECD (y1) and log of preoperative ECD (x1) at 2 years postoperatively, y1 = 2.513x1-6.2816 (n = 62, r= 0.3503, P = 0.005); (2) mean ECD (y2) and log time (in months, x2), y2= 2543.7-36.997x2-38.99x2 (r=-0.9654, n = 7, P = 0.0004); and (3) mean axial distance between the front surface of the crystalline lens and the TICL back surface (y3) and time postoperatively (in months, x3), y3 = 0.1035x3-5.2808x3 +473.18 (r = 0.8512, n = 7, P = 0.015).

CONCLUSIONS

Expected ECD loss after TICL implantation by 2 years postoperatively is predictable. On average, over 3 years after implantation, there is (1) an initial rapid decline in ECD, followed by a gradual fall in the rate of cell loss, and (2) a gradual fall in the distance between the TICL and the crystalline lens by 2 years postoperatively, followed by a reversal by the third year.

Visual outcomes of Visian ICL implantation for high myopia in patients with shallow anterior chamber depth

Background

High myopia with shallow anterior chamber depth (ACD less than 2.8 mm) is not rare. This observational study aims to evaluate visual outcomes after implantation of the Visian Implantable Collamer Lens with a central hole (ICL V4c) in these patients.

Methods

A prospective cohort of consecutive 51 eyes of 31 patients (20 to 42 years old) was followed for at least 12 months (average 15.35 ± 4.90 months, rangers from 12 to 25 months). The preoperative ACD was 2.74 ± 0.04 mm (2.65 to 2.79 mm). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), intraocular pressure (IOP), manifest refraction, vault, and endothelial cell density (ECD) were measured during the follow-ups after surgery.

Results

All surgeries were performed safely and no complication was observed during the follow-ups. At the last follow-up, the safety index (postoperative CDVA / preoperative CDVA) was 1.33 ± 0.60 and the efficacy index (postoperative UDVA / preoperative CDVA) was 1.14 ± 0.54. After the surgery, no eye had decreased CDVA and 59% (30 eyes) of the eyes gained at least one line. Forty-seven eyes (92%) were within ±1.0 D and 35 eyes (69%) were within ±0.5 D of the attempted refraction. The mean postoperative vault was 380.00 ± 152.84 μm (90 to 700 μm). The ECD was reduced by 8.38 ± 0.06% as compared to the preoperative value (p < 0.001). No significant change was observed in IOP (p = 0.061) at the last follow-up. Ultrasound Biomicroscopy (UBM) showed none of the eyes had trabecular-iris angle closed.

Conclusions

In this prospective observational study, ICL V4c implantation in patients with high myopia and shallow ACD achieved satisfying and stable visual outcomes. Its long-term safety and stability require further investigation.

Trial registration

This trial was retrospectively registered on 05/08/2018 under the number (ChiCTR1800017594).

Refractive surgery

Refractive surgery has evolved beyond laser refractive techniques over the past decade. Laser refractive surgery procedures (such as laser in-situ keratomileusis), surface ablation techniques (such as laser epithelial keratomileusis), and photorefractive keratectomy have now been established as fairly safe procedures that produce excellent visual outcomes for patients with low-to-moderate amounts of ametropia. Additionally, a broader selection of options are now available to treat a wider range of refractive errors. Small incision lenticule extraction uses a femtosecond laser to shape a refractive lenticule, which is removed through a small wound. The potential advantages of this procedure include greater tectonic strength and less dry eye. In the future, intracorneal implants could be used to treat hyperopia or presbyopia. Phakic intraocular implants and refractive lens exchange might be useful options in carefully selected patients for correcting high degrees of ametropia. Thus, physicians are now able to provide patients with the appropriate refractive corrective option based on the individual's risk-benefit profile.

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.

Off-Label Use of Phakic Intraocular Lens with a "Piggyback" Technique

Purpose

We report a case of a highly myopic pseudophakic patient who received off-label placement of a phakic intraocular lens (pIOL) via a “piggyback” technique, allowing the placement of an intraocular lens (IOL) in his fellow eye, resulting in improved visual acuity and emmetropia.

Case Report

A 66-year-old, highly myopic, pseudophakic male with an IOL implant in his left eye was referred for second opinion for surgical options for his phakic right eye. Given the severe myopic status of both eyes, he received off-label placement of a posterior chamber pIOL with a piggyback technique for the pseudophakic left eye followed by standard cataract surgery and intraocular lens implantation in the right eye. For the left eye, uncorrected best visual acuity improved from 20/70 to 20/25.

Conclusion

This case demonstrates the successful off-label use of a phakic IOL in a pseudophakic, highly myopic patient with a piggyback technique, resulting in improved visual acuity and ultimately allowing IOL placement in the fellow eye for emmetropia. This off-label use of pIOL can offer ophthalmologists an alternative option for pseudophakic patents with severe refractive error.

Verisyse versus Veriflex Phakic Intraocular Lenses: Refractive Outcomes and Endothelial Cell Density 5 Years after Surgery

Purpose

To compare refractive stability, central endothelial cell density (ECD), and complications between Verisyse (Abbott Medical Optics, Netherlands) and Veriflex (Abbott Medical Optics, Netherlands) phakic intraocular lenses (pIOL) over five years.

Methods

We retrospectively reviewed the medical records of patients who underwent Verisyse or Veriflex pIOL implantation for surgical correction of myopia. Patients with a 5-year follow-up period were included in the study. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent of manifest refraction (SE), and ECD were compared between the groups preoperatively and 1, 3, and 5 years postoperatively.

Results

The study included 47 eyes in the Verisyse group and 50 eyes in the Veriflex group. There was no significant difference in mean SE, UDVA, CDVA, and ECD preoperatively or postoperatively. In both groups, there was a statistically significant myopic shift between 1-year and 5-year visits (−0.25 ± 0.30 D and −0.23 ± 0.48 D in the Verisyse and Veriflex groups, respectively). There was no significant difference between the groups in terms of efficacy and safety indexes at 5 years. ECD loss was highest during the first year (3.9% loss in the Verisyse group and 3.9% loss in the Veriflex group, p=0.670). At 5 years, the mean cumulative ECD losses in the Verisyse and Veriflex groups were 7.42% and 7.64%, respectively (p=0.709). Cataracts developed in 2.1% of the eyes in the Verisyse group and in 2.0% of those in the Veriflex group. No sight-threatening complications were observed.

Conclusion

Verisyse and Veriflex pIOLs are highly effective for treating high myopia up to 5 years after surgery. Longitudinal studies with longer follow-up periods are necessary to determine the endothelial safety profile.

Implantable collamer lens with central hole: 3-year follow-up

Purpose

To evaluate the long-term predictability, stability, safety, and efficacy of the V4c Visian implantable collamer lens (ICL) with central hole to correct myopia.

Patients and methods

One hundred and eighty-four eyes of 92 patients were evaluated during 3 years after implantation of the V4c ICL. The refraction, uncorrected distance visual acuity, best-corrected distance visual acuity, IOP, endothelial cell count, vault, and adverse effects were evaluated every 12 months during the whole follow-up.

Results

The mean spherical equivalent dropped from -8.30±2.98 D preoperatively to −0.37±0.47 D at 36 months post-surgery, with 91.8% eyes being within ±1.00 D of emmetropia. With respect to the astigmatic components J0 and J45, 98.4% and 99.5% of eyes, respectively, were within ±0.50 D of the desired refraction. At 36 months, 78.8% of eyes had no change in the Snellen lines of best-corrected distance visual acuity, while 8.7% gained one line and 6.5% gained two or more lines; mean safety and efficacy indexes were 1.03 and 0.90, respectively. Mean endothelial cell count was 2,742±340 cells/mm² before and 2,663±366 cells/mm² at 36 months post-surgery. Mean IOP reduced from 13.7±1.9 mmHg preoperatively to 12.8±1.7 mmHg at 36 months post-surgery. Mean vault varied from 409±196 µm at 12 months to 349±165 µm at 36 months.

Conclusion

The visual and refractive outcomes were very good and highly stable throughout the follow-up period, indicating that this ICL model may be predictable, stable, safe, and effective to correct myopia in the long term.