Surface properties of commercially available hydrophobic acrylic intraocular lenses: Comparative study

Biopolymeric Innovations in Ophthalmic Surgery: Enhancing Devices and Drug Delivery Systems

The interface between material science and ophthalmic medicine is witnessing significant advances with the introduction of biopolymers in medical device fabrication. This review discusses the impact of biopolymers on the development of ophthalmic devices, such as intraocular lenses, stents, and various prosthetics. Biopolymers are emerging as superior alternatives due to their biocompatibility, mechanical robustness, and biodegradability, presenting an advance over traditional materials with respect to patient comfort and environmental considerations. We explore the spectrum of biopolymers used in ophthalmic devices and evaluate their physical properties, compatibility with biological tissues, and clinical performances. Specific applications in oculoplastic and orbital surgeries, hydrogel applications in ocular therapeutics, and polymeric drug delivery systems for a range of ophthalmic conditions were reviewed. We also anticipate future directions and identify challenges in the field, advocating for a collaborative approach between material science and ophthalmic practice to foster innovative, patient-focused treatments. This synthesis aims to reinforce the potential of biopolymers to improve ophthalmic device technology and enhance clinical outcomes.

Quantification of Straylight Induced by Silicone Oil Adherent to Intraocular Lenses of Different Materials

PURPOSE

A complication of using silicone oil as an intraocular endotamponade is its adhesion to intraocular lenses (IOLs). Forward light scattering is a measure to quantify the optical disturbance caused by adherent oil droplets. We tested the straylight caused by silicone oil adhesion to different IOLs and examined whether an approved cleaning solution, F4H5, reverses the induced straylight.

DESIGN

An experimental study.

METHODS

Two hydrophobic acrylic IOL models and 1 hydrophilic model with a hydrophobic surface (n = 8 per model: 24 lenses) had straylight measured before contact with silicone oils, providing a baseline for subsequent testing: 12 lenses with lighter-than-water silicone oil (Siluron 2000) and 12 with heavier-than-water oil (Densiron 68). The final measurement was performed after cleansing with F4H5 when we used scanning electron and light microscopy to detect surface changes.

RESULTS

Straylight was majorly increased in IOLs with adherent silicone oil (baseline vs adherent oil median 3.1 [2.1, 3.9] and 39.7 [22.7, 87.8] deg2/sr, respectively; P < .001). No difference was seen between heavier- and lighter-than-water silicone oils. Between IOL types, induced straylight varied significantly, with 1 hydrophobic model reaching the highest average straylight. F4H5 significantly reduced straylight values in all IOL types (median 9.4 [5.4, 13.8] deg2/sr). The microscopy revealed surface changes on the IOLs even after cleaning.

CONCLUSIONS

Silicone oil adhesion to IOLs can induce amounts of straylight known to cause severe optical disturbance. F4H5 cleansing solution reversed straylight values to only slightly increased values. We found no difference in straylight formation between the lighter- and heavier-than-water silicone oils.

Clinical Outcomes of a Monofocal, Optimized, Aspheric, Hydrophobic Acrylic Intraocular Lens Implant

Purpose

To evaluate the refractive and visual outcomes of eyes implanted with monofocal, optimized, aspheric, hydrophobic acrylic intraocular lenses (IOL) following cataract surgery.

Methods

The study assessed 55 eyes implanted with CT LUCIA® 621P IOLs (Carl Zeiss Meditec AG, Jena, Germany) at 3-months postsurgery. The main outcome measures were refractive error, monocular corrected distance visual acuity (CDVA), monocular uncorrected distance visual acuity (UDVA), photopic and mesopic contrast sensitivity, and wavefront aberrations. Patients were asked to complete the Catquest-9SF questionnaire.

Results

At 3 months, the cumulative Snellen visual acuity was 20/20 in 94.55% of eyes and 20/25 or better in 100%. The difference between the UDVA and CDVA was either the same (70.91%) or better (29.09%) in all eyes. The mean Snellen decimal UDVA and DCVA were 1.07 ± 0.15 and 1.13 ± 0.11, respectively. The safety and efficacy indexes were 1.48 and 1.40, respectively. 47.27% of eyes showed a spherical equivalent ±0.13 D, with 92.73% of the eyes were within ±0.50 D and all eyes were within ±1.00 D. The mean spherical equivalent was -0.03 ± 0.30 D and the mean refractive cylinder -0.36 ± 0.34 D. The log photopic and mesopic contrast sensitivity functions were good and similar for all spatial frequencies. All patients reported being either fairly satisfied (score 3) or very satisfied (score 4) with their vision (mean = 3.64 ± 0.49). No intra- and postoperative complications were reported during the 3 months of follow-up.

Conclusion

The current study demonstrates that excellent visual and refractive outcomes, as well as patient satisfaction, can be achieved after cataract surgery with optimized, aspheric CT LUCIA 621P monofocal IOLs.

Current State of the Art and Next Generation of Materials for a Customized IntraOcular Lens according to a Patient-Specific Eye Power

Intraocular lenses (IOLs) are commonly implanted after surgical removal of a cataractous lens. A variety of IOL materials are currently available, including collamer, hydrophobic acrylic, hydrophilic acrylic, PHEMA copolymer, polymethylmethacrylate (PMMA), and silicone. High-quality polymers with distinct physical and optical properties for IOL manufacturing and in line with the highest quality standards on the market have evolved to encompass medical needs. Each of them and their packaging show unique advantages and disadvantages. Here, we highlight the evolution of polymeric materials and mainly the current state of the art of the unique properties of some polymeric systems used for IOL design, identifying current limitations for future improvements. We investigate the characteristics of the next generation of IOL materials, which must satisfy biocompatibility requirements and have tuneable refractive index to create patient-specific eye power, preventing formation of posterior capsular opacification.

Twelve-Months Follow-Up Postmarket Study of a Hydrophobic Intraocular Lens Using a Preloaded Automated Injector in an Indian Population

Purpose

To assess real-world clinical outcomes and safety of the Clareon^® intraocular lens (IOL) and AutonoMe^® automated preloaded delivery system in an Indian population.

Patients and methods

This was a prospective, single-arm, multicenter, 12-month clinical study in patients aged ≥20 years with unilateral or bilateral cataracts. Surgery was performed by phacoemulsification followed by implantation of the Clareon monofocal IOL (CNA0T0). Monocular best-corrected distance visual acuity (BCDVA) and uncorrected distance visual acuity (UCDVA) were assessed at 1 week and 1, 6, and 12 months after implantation. Posterior capsular opacification (PCO), surface haze, and glistenings were evaluated at all visits. Surgeons' satisfaction with automated injector system was also evaluated using a questionnaire. Safety was assessed by monitoring adverse events (AEs).

Results

A total of 151 eyes received the CNA0T0 IOL. Mean ± SD monocular BCDVA improved from 0.53±0.44 logMAR preoperatively to 0.00±0.08 logMAR at week 1 and -0.03±0.08 logMAR at 12 months after implantation. At 12 months, 137/137 (100%) of eyes achieved BCDVA of 0.3 logMAR or better. Mean ± SD monocular UCDVA was 0.78±0.40 logMAR preoperatively, 0.11±0.15 logMAR at week 1, and 0.08±0.13 logMAR at 12 months after implantation. At 12 months, 132/137 (96%) eyes achieved UCDVA of 0.3 logMAR or better. Serious intraoperative AEs were posterior capsule rupture (n=1) and ciliary zonular dehiscence (n=1). Surgeons reported that the automated preloaded device was more intuitive compared with other push- or screw-style preloaded injector systems. None of the eyes in this study presented surface haze; all were graded as 0 glistenings at all visits. No clinically significant PCO or neodymium-doped yttrium aluminum garnet (Nd:YAG) capsulotomies were reported.

Conclusion

The hydrophobic IOL preloaded in an automated injector system provided good visual and refractive outcomes, as well as no surface haze and grade 0 glistenings. None of the patients required Nd:YAG capsulotomy.

Refractive and Visual Outcomes of a Monofocal Non-Constant Aberration Aspheric Intraocular Lens

Purpose

To evaluate the refractive and visual outcomes following cataract surgery and implantation of a new monofocal non-constant aberration aspheric intraocular lens (IOL).

Methods

Ninety eyes of 86 patients who underwent implantation the CT LUCIA 621P IOL (Carl Zeiss Meditec AG) were retrospectively analyzed in this study. Main outcome measures were refractive error and monocular corrected distance visual acuity (CDVA) and monocular uncorrected distance visual acuity (UDVA) values. Patients were evaluated at 1-month post-surgery and intra- and post-operative complications were recorded.

Results

Eighty percent of the eyes showed a CDVA of 20/25 or better before surgery. The postoperative mean values of monocular distance Snellen decimal UDVA and CDVA were 0.64±0.22 and 0.89±0.13, respectively. All eyes showed the same or better difference between UDVA and CDVA. In relation to the postoperative spherical equivalent, the highest percentage of eyes, 31.11%, was for the range between −0.50 and −0.14D followed by 22.22% for the ±0.13D range. Ninety percent of the eyes were within ±1.00 D and 73.33% of eyes within ±0.50 D. The mean postoperative spherical equivalent was −0.18±0.55D. 37.78% and 76.67% of the eyes showed a value ≤0.50 D and ≤1.00D, respectively, being the mean postoperative refractive cylinder −0.81±0.50D. No adverse events were reported in whole sample intra and postoperatively.

Conclusion

The present study shows that cataract surgery with an monofocal non-constant aberration aspheric IOL implantation resulted in good visual performance and refractive outcomes. This lens may be considered as a valid choice for patients in a standard-routine cataract surgery practice.

Predictive accuracy of an intraoperative aberrometry device for a new monofocal intraocular lens

PURPOSE

To evaluate refractive outcomes for the Clareon monofocal intraocular lens (IOL) in terms of achieved target refraction for the ORA (ALCON) intraoperative wavefront aberrometry device and preoperative noncontact biometry.

SETTING

University Eye Clinic Maastricht, Maastricht University Medical Center+, the Netherlands.

DESIGN

Prospective observational clinical trial.

METHODS

Patients with bilateral age-related cataracts undergoing phacoemulsification, either by delayed sequential surgery or on the same day, were included in the study. Exclusion criteria were an increased risk for refractive surprise or complicated surgery. Implanted IOL power was based on noncontact optical biometry data using the Barrett Universal II (BU-II) formula, optimized for the Clareon IOL. Postoperative subjective refraction was measured 4 to 6 weeks after surgery. Catquest-9SF questionnaires were completed preoperatively and 3 months after surgery.

RESULTS

100 eyes (51 patients) were included. The percentages of eyes within 1.0 diopters (D), 0.75 D, 0.50 D, and 0.25 D of target for ORA vs BU-II were 84% (84 eyes), 72% (72 eyes), 57% (57 eyes), and 21% (21 eyes) vs 97% (97 eyes), 88% (88 eyes), 77% (77 eyes), and 53% (53 eyes), respectively. Mean absolute prediction error was significantly higher for ORA vs preoperative biometry (P < .001). After global optimization, the prediction accuracy of ORA improved significantly (P < .001). Catquest-9SF questionnaires showed improved levels of ability at 3 months after surgery (P < .001).

CONCLUSIONS

This study showed lower percentages of eyes within target refraction for ORA (prior to lens constant optimization) compared with the BU-II formula when implanting the Clareon IOL. However, prediction accuracy of ORA improved significantly after global optimization. Therefore, further intraoperative measurements, postoperative measurements, and optimization are needed to improve the ORA prediction for this IOL.

Automatic segmentation of intraocular lens, the retrolental space and Berger's space using deep learning

PURPOSE

To develop and validate a deep learning model to automatically segment three structures using an anterior segment optical coherence tomography (AS-OCT): The intraocular lens (IOL), the retrolental space (IOL to the posterior lens capsule) and Berger's space (BS; posterior capsule to the anterior hyaloid membrane).

METHODS

An artificial intelligence (AI) approach based on a deep learning model to automatically segment the IOL, the retrolental space, and BS in AS-OCT, was trained using annotations from an experienced clinician. The training, validation and test set consisted of 92 cross-sectional OCT slices, acquired in 47 visits from 41 eyes. Annotations from a second experienced clinician in the test set were additionally evaluated to conduct an inter-reader variability analysis.

RESULTS

The AI model achieved a Precision/Recall/Dice score of 0.97/0.90/0.93 for IOL, 0.54/0.65/0.55 for retrolental space, and 0.72/0.58/0.59 for BS. For inter-reader variability, Precision/Recall/Dice values were 0.98/0.98/0.98 for IOL, 0.74/0.59/0.62 for retrolental space, and 0.58/0.57/0.57 for BS. No statistical differences were observed between the automated algorithm and the inter-reader variability for BS segmentation.

CONCLUSION

The deep learning model allows for fully automatic segmentation of all investigated structures, achieving human-level performance in BS segmentation. We, therefore, expect promising applications of the algorithm with particular interest in BS in automated big data analysis and real-time intra-operative support in ophthalmology, particularly in conjunction with primary posterior capsulotomy in femtosecond laser-assisted cataract surgery.

Atomic force microscopy comparative analysis of the surface roughness of two posterior chamber phakic intraocular lens models: ICL versus IPCL

BACKGROUND

To compare the anterior surface roughness of two commercially available posterior chamber phakic intraocular lenses (IOLs) using atomic force microscopy (AFM).

METHODS

Four phakic IOLs were used for this prospective, experimental study: two Visian ICL EVO+ V5 lenses and two iPCL 2.0 lenses. All of them were brand new, were not previously implanted in humans, were monofocal and had a dioptric power of - 12 diopters (D). The anterior surface roughness was assessed using a JPK NanoWizard II® atomic force microscope in contact mode immersed in liquid. Olympus OMCL-RC800PSA commercial silicon nitride cantilever tips were used. Anterior surface roughness measurements were made in 7 areas of 10 × 10 μm at 512 × 512 point resolution. The roughness was measured using the root-mean-square (RMS) value within the given regions.

RESULTS

The mean of all anterior surface roughness measurements was 6.09 ± 1.33 nm (nm) in the Visian ICL EVO+ V5 and 3.49 ± 0.41 nm in the iPCL 2.0 (p = 0.001).

CONCLUSION

In the current study, we found a statistically significant smoother anterior surface in the iPCL 2.0 phakic intraocular lenses compared with the VISIAN ICL EVO+ V5 lenses when studied with atomic force microscopy.

Analysis of opacification patterns in intraocular lenses (IOL)

Objective

Intraocular lens (IOL) opacification may cause severe visual impairment. The pathogenesis remains unclear. The aim of this study was to analyse opacification patterns in different IOLs. Therefore, this multicentre, retrospective, observational study was conducted at Ludwig-Maximilians-University, Munich, Germany and University-Hospital Basel, Switzerland.

Methods and analysis

In this study, 75 opacified IOLs were identified and classified after extraction. Macroscopical photo documentation, light and electron microscopic analysis were done.

Results

68 acrylic-hydrophilic single-piece-IOLs, 1 acrylic-hydrophilic 3-piece-IOL, 6 acrylic-hydrophobic 3-piece-IOLs were extracted. The dataset comprised IOLs known for opacification and IOLs not having been reported yet. 67 IOLs showed a fine-granular and 8 IOLs a crust-like opacification pattern. According to literature, 62 of the fine-granular opacified IOLs were graded into type 1 (processing/packaging-induced primary opacification) and 13 into type 2 (secondary opacification of unknown aetiology). The anterior surface of the IOLs was affected in all 75 IOLs, the posterior surface only in 23 cases. Of all 67 fine-granular IOLs, 43 had a central defect and 21 had a zone without opacification (clear islet).

Conclusion

In our series, the morphology of IOL opacification did not follow the existing pathogenetic classification that strictly discriminates between primary and secondary causes. Fine-granular IOL opacification occurs with similar patterns in both type 1 and type 2 IOL opacification, while a crust-like pattern was only detected in type 2 IOL opacifications. Consequently, susceptibility of an IOL to opacification is caused by a multifactorial combination of material and processing properties as well as individual (pathological) conditions of the patient.

Comparison of posterior capsule opacification between Clareon CNA0T0 and Tecnis ZCB00 intraocular lenses

INTRODUCTION

The purpose is to compare posterior capsule opacification (PCO) and its impact on vision between Clareon CNA0T0 (Alcon) and Tecnis ZCB00 intraocular lenses (IOLs) (Johnson&Johnson) 1, 6, and 12 months after implantation.

METHODS

A prospective observational study was performed at the Nuestra Señora de Gracia Hospital (Zaragoza, Spain). Fifty eyes (50 patients) with Tecnis IOL (group 1) and 60 eyes (60 patients) with Clareon IOL (group 2) were enrolled. One, 6, and 12 months after age-related cataract surgery by five different surgeons, the following tests were performed: mesopic corrected distance visual acuity (CDVA), CSV1000-E test, KR-1W wavefront analyzer, OQAS II, Catquest-9SF questionnaire and mydriatic slit-lamp pictures. PCO intensity was quantified and the area of opacification was measured using ImageJ (NIH).

RESULTS

Mean age was 71.20 ± 6.79 years in group 1, and 71.73 ± 8.17 years in group 2 (p = 0.72); mean axial length was 23.46 ± 1.14 and 23.53 ± 0.91 mm, respectively (p = 0.72); mean IOL power was 21.69 ± 2.26 D and 21.28 ± 2.44 D, respectively (p = 0.37). One month after surgery there were differences in intensity of PCO (0.73 ± 0.60 and 1.05 ± 0.71, respectively, p = 0.02). Six months after surgery statistical differences were found in VA with 20% CS in mydriatic conditions (0.26 ± 0.21 logMAR (20/36) and 0.18 ± 0.17 logMAR (20/30), respectively, p = 0.04). Twelve months after surgery, no differences were detected between groups. As for the evolution of PCO within the Clareon group, high order aberrations (p < 0.05) and the Strehl ratio (p = 0.02) decreased.

CONCLUSION

There are no differences in slit-lamp pictures or visual function between both IOLs during the first 12 months after implantation.

Refractive stability of a new single-piece hydrophobic acrylic intraocular lens and corneal wound repair after implantation using a new automated intraocular lens delivery system

PURPOSE

To investigate refractive stability and characterize corneal incision repair up to 3 months after implantation of a new hydrophobic acrylic intraocular lens (IOL) with hydroxyethylmethacrylate using a new automated IOL delivery system.

METHODS

This prospective case series included 50 eyes of 50 patients undergoing phacoemulsification and implantation of the Clareon® CNA0T0 IOL using the AutonoMe® automated delivery system in the Department of Ophthalmology, Keio University School of Medicine. The clinical data were collected from 46 eyes of 46 patients preoperatively and 1 day, 1 week, and 1 and 3 months postoperatively. Endothelial-side incision gaping, posterior incision retraction, and Descemet's membrane detachment were recorded as present or absent using anterior-segment optical coherence tomography postoperatively.

RESULTS

The uncorrected distance and corrected distance visual acuities improved and stabilized 1 week postoperatively. The anterior chamber depth was stable from 1 week postoperatively. The subjective refraction was stable from 1 day postoperatively. Descemet's membrane detachments and endothelial-side wound gaping were seen in 19 (41.3%) eyes and 34 (73.9%) eyes 1 day postoperatively and decreased gradually. Posterior incision retraction was seen in eight eyes (17.4%) on day 1 and increased to 19 eyes (41.3%) 3 months postoperatively.

CONCLUSIONS

The Clareon IOL had excellent refractive stability from day 1 postoperatively. The AutonoMe automated delivery system enables safe IOL implantation through a 2.4-mm corneal incision, although the wound required longer than 1 month to heal postoperatively.

Posterior Capsule Opacification With Two Hydrophobic Acrylic Intraocular Lenses: 3-Year Results of a Randomized Trial

PURPOSE

To compare the incidence and intensity of posterior capsule opacification (PCO) and neodymium-yttrium-aluminum-garnet (Nd:YAG) capsulotomy rates between 2 similar open-loop single-piece hydrophobic acrylic intraocular lenses (IOLs) that differ in the proprietary material characteristics and design features, over a period of 3 years.

DESIGN

Randomized, prospective, patient- and examiner-masked clinical trial with intraindividual comparison.

METHODS

Setting: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

PATIENT POPULATION

Eighty patients (160 eyes) had bilateral cataract surgery and received a Vivinex XY1 IOL in 1 eye and an AcrySof SN60WF IOL in the other eye.

OBSERVATION PROCEDURES

Follow-up examinations were performed 3 years after surgery. Digital retroillumination images were taken of each eye. The amount of PCO (score: 0-10) was assessed subjectively at the slit lamp and objectively using automated image analysis software (AQUA).

MAIN OUTCOME MEASURE

PCO score (scale, 0-10).

RESULTS

The mean objective PCO score of the Vivinex XY1 IOLs was 0.9 ± 0.8 compared to the PCO score of 1.4 ± 1.1 for the AcrySof SN60WF IOLs (P < .001). Three years postoperatively, 11.4% of patients had an Nd:YAG capsulotomy in the Vivinex XY1 eye and 18.6% had a capsulotomy in the AcrySof SN60WF eye (P = .23).

CONCLUSION

The new hydrophobic acrylic Vivinex XY1 IOL showed significantly lower PCO rates and lower YAG rates compared to the AcrySof SN60WF IOL. The interaction of various factors such as hydrophobic material, smooth optic surface, and sharp posterior optic edge plays a key role in PCO development.

Visual and refractive outcomes and glistenings occurrence after implantation of 2 hydrophobic acrylic aspheric monofocal IOLs

PURPOSE

To compare the Clareon IOL with the Tecnis PCB00 IOL in terms of visual performance, refractive outcomes, glistenings occurrence, and quality-of-life outcomes.

SETTING

Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom.

DESIGN

Single-center, single-masked, prospective, randomized controlled trial.

METHODS

One hundred thirty-nine patients with bilateral cataracts were randomized to receive the Clareon (C IOL) or Tecnis (T IOL) IOL. Visual acuity, refraction, central corneal thickness (CCT), endothelial cell loss, contrast sensitivity, mesopic gap acuity, evaluation of glistenings, and rates of perioperative and postoperative complications were recorded. Quality-of-life outcomes were measured with the EuroQOL-5 dimensions questionnaire and the patient-reported outcome measures (PROMs) questionnaire. Optimized A-constants were available for the T IOL but not for the C IOL.

RESULTS

Seventy-one patients (140 eyes) received the C IOLs and 68 patients (134 eyes) received the T IOLs. Data were analyzed for the first implanted eye. At 12 months, mean uncorrected distance visual acuity (logarithm of the minimum angle of resolution) was 0.02 ± 0.10 and 0.01 ± 0.08 (mean ± SD; P = .49; 95% CI, -0.02 to 0.04) in the C IOL and T IOL groups, respectively. Corrected distance visual acuity was -0.02 ± 0.09 and -0.03 ± 0.06, respectively (P = .45; 95% CI, -0.02 to 0.04). The increase in CCT was 14 ± 19 and 16 ± 28 μm, respectively (P = .63; 95% CI, -10.16 to 6.16). Mean absolute refraction spherical equivalent error from target refraction was 0.41 ± 0.28 for the C IOL and 0.25 ± 0.2 for the T IOL groups (P = .002; 95% CI, 0.08 to 0.24). Glistenings were minimal (median grade 0), with no difference in grades between groups (P = .2). PROMs improved postoperatively and were similar in both groups.

CONCLUSIONS

There were no differences in visual outcomes between the Clareon IOL and Tecnis PCB00 IOL. Glistenings were rarely observed in either IOL with no difference in grades. There was no difference in perioperative or postoperative complications. Surgeon optimization of the A-constant for the Clareon IOL is recommended.