Effect of Nd:YAG laser posterior capsulotomy on intraocular pressure, refraction, anterior chamber depth, and macular thickness

Knowledge mapping of posterior capsular opacification from 2011 to 2023: A bibliometric analysis

This bibliometric analysis explores the current status and trends of global research on posterior capsular opacification (PCO). A search of the Web of Science Core Collection (WoSCC) database was conducted to identify publications on PCO from 2011 to 2023. Bibliometric analysis was used to explore publication trends in PCO-related research. VOSviewer v.1.6.20 was used to visualize country, institution and author productivity and collaborations, as well as research hotspots. CiteSpace 6.3.R1 was applied to extract the burst references and keywords. A total of 988 PCO-related documents were included. The largest number of publications (283) and citations (3538) were from China. Of these, the largest number of publications (41) and citations (655) were from Wenzhou Medical University. Quankui Lin published 31 articles and was the most productive author. The journal with the highest productivity (121 publications) was the Journal of Cataract and Refractive Surgery. The top 3 cited references mainly presented intraocular lens (IOL) optic material/design and surgical technique on the development of PCO; the mechanism of PCO formation. The keywords mainly formed 5 clusters: the prevalence and risk factors for PCO; the mechanism of PCO formation; the material and design of IOLs and their application in the prevention of PCO; the application of IOLs surface modification and drug delivery in the prevention of PCO; and complications associated with Nd:YAG laser capsulotomy. Based on the raw data from WoSCC, analyzing research hotspots can offer valuable insights into PCO studies.

Clinical evaluation of Nd:YAG capsulotomy on the light-adjustable intraocular lens

PURPOSE

To investigate the safety and refractive outcomes of Nd:YAG capsulotomy in pseudophakic eyes with the light-adjustable intraocular lens (LAL) both before and after completing the light delivery device lock-in treatments.

SETTING

Private practice in Orange, California.

DESIGN

Retrospective, comparative study.

METHODS

Patients were divided into 2 groups according to the timing of their YAG capsulotomy (Group I underwent YAG capsulotomy before lock-in treatments and Group II underwent YAG capsulotomy on completion of lock-in treatments). Sphere, cylinder, axis, spherical equivalent (SE), uncorrected distance visual acuity (UDVA), and corrected distance visual acuity (CDVA) were compared preoperatively and postoperatively using 2-tailed paired t tests. Postoperative data were measured 1 month after Nd:YAG capsulotomy. The α level (type I error) was set at 0.05.

RESULTS

The LAL was successfully implanted in 485 eyes from January 2020 to March 2023. 10 eyes (0.02%) needed YAG capsulotomy before the completion of lock-in treatments (Group I), and 28 eyes (5.77%) needed YAG capsulotomy after the lock-in was completed (Group II). Postoperative CDVA significantly improved compared with preoperative values in both groups. Changes in sphere, cylinder, axis, SE, and UDVA preoperative and postoperative measurements were not statistically significant ( P > .05) in both groups.

CONCLUSIONS

YAG capsulotomy can be safe and effective for patients with the LAL who develop posterior capsular opacification during the adjustment period. There were no significant changes in sphere, cylinder, axis, or spherical equivalence after YAG capsulotomy in both groups.

Evaluation of Intraocular Pressure, Refraction, Anterior Chamber Depth, Macular Thickness, and Specular Microscopy Post-Neodymium-Doped Yttrium-Aluminum-Garnet Laser in Patients With Posterior Capsular Opacification

Background Cataract is the leading cause of blindness globally, particularly in India. Despite advancements in surgical techniques, postoperative complications remain common, with posterior capsular opacification (PCO) being the most frequent issue. Although neodymium-doped yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy is recommended for managing PCO, it is associated with various side effects. This study aimed to evaluate the effects of Nd:YAG laser capsulotomy on intraocular pressure (IOP), visual acuity, anterior chamber depth (ACD), macular thickness, and corneal endothelium in Indian patients. Methodology This prospective, hospital-based study was conducted in the ophthalmology department at a tertiary care center in western Maharashtra from September 2022 to June 2024. Approval from the Institutional Scientific and Ethics Committee was obtained before commencing the research. In the study, 72 eyes from 72 patients with PCO following uncomplicated cataract surgery who were undergoing Nd:YAG laser capsulotomy were included, whereas patients with corneal pathology, retinal pathology, complicated cataract surgery, or trauma were excluded. Patients with active uveitis, non-compliant patients, and those unwilling to undergo the procedure were also excluded. Written informed consent was obtained from each patient. Data were managed in Microsoft Excel, and statistical analysis was conducted using the SPSS 26.0 software. As the continuous variables exhibited skewed distribution, the Wilcoxon test was employed to assess categorical variables such as the significance of IOP and endothelial cell differences over time. A significance level of 5% was assumed, with a p-value below 0.05 considered significant. Results The mean age of patients who underwent Nd:YAG capsulotomy was 64 years, with a female predominance of 37 (51.4%). In the study, 37 (51.4%) patients had their left eye treated, while 35 (48.6%) had their right eye treated. Overall, 45 (62.5%) patients had a baseline best-corrected visual acuity (BCVA) of 6/24-6/12. At one hour post-procedure, 46 (63.9%) patients in Group II had a BCVA of 6/24-6/12, and by one week after treatment, 53 (73.6%) patients had a BCVA of >6/12-6/6. ACD was normal in all patients before and after the procedure. Two patients developed macular edema at one hour and one week after the procedure. The mean IOP at baseline, one hour, and one week were 13.5, 13.86, and 13.69 mmHg, respectively. A significant increase in IOP was observed at one hour post-procedure, along with a significant decrease in endothelial cell count compared to baseline, which also persisted at one week. Conclusions Patients undergoing Nd:YAG capsulotomy experienced an initial rise in IOP, followed by a subsequent decline. Improved visual acuity was noted in most patients at one hour and by one week. A significant decline in endothelial cell count was observed following the procedure, and macular edema was noted in two patients. Anterior chamber reaction was observed in nearly all patients, which decreased by one week. With no change in ACD following the procedure up to one week, ocular refraction was not significantly impacted in the short term. Therefore, further large-scale intervention studies are needed to evaluate the effects of Nd:YAG laser capsulotomy size and the energy used on refractive error and post-procedure complications, as well as to explore the long-term effects on IOP.

Neodymium-doped yttrium aluminum garnet (Nd: YAG) laser treatment in ophthalmology: a review of the most common procedures Capsulotomy and Iridotomy

Nowadays, lasers are used in various medical fields. Ophthalmology was the first medical specialty to utilize lasers in patient treatment and still remains the leading medical field that uses laser energy for both therapeutic and diagnostic purposes. The neodymium: yttrium-aluminum-garnet (Nd: YAG) laser is one of the most common lasers used in ophthalmology. It is a solid-state laser with a wavelength of 1064 nm that works on the principle of photodisruption. Since its introduction in ophthalmology over 40 years ago, it has found various applications, mainly for procedures where cutting or disruption of ocular tissue is required. Compared to surgical alternatives, the use of Nd: YAG lasers on ocular tissue is minimally invasive. In this review, we focus on the two most common ophthalmic applications of Nd: YAG laser - laser peripheral iridotomy and posterior capsulotomy. The history of the techniques, current trends, potential complications, and the prognosis for future use is discussed.

Self-assembled coating with a metal-polyphenolic network for intraocular lens modification to prevent posterior capsule opacification

Posterior capsule opacification (PCO) is a main complication after cataract surgery and intraocular lens (IOLs) implantation and is attributed to residual lens epithelial cells (LECs) migrating to the IOL surface and posterior capsules. IOL surface modification has been a newly-developing research filed in recent years; however, the applicability and economical acquisition of modified materials remain unsolved. In this study, we first applied a metal-polyphenolic network coating with a self-assembly technique on the IOL surface by using tannic acid (TA) combined with AlCl3, which are easily acquire and applying on the IOL surface to solve the IOL transmittance affair. Using wound healing and Transwell assay to verify AZD0364 inhibits cell migration (P< 0.05), the lipopolysaccharide-induced macrophage inflammation model to verify pterostilbene (PTE) inhibits the inflammatory reaction (P< 0.01). By optimizes its self-assembly coating parameters and calculating its drug release kinetics, we successfully loaded these two drugs on the coating, named TA (AZD0364/PTE) IOL. Its surface morphology characteristics were analyzed by scanning electron microscope, x-ray photoelectron spectrometer and water contact angle. The optical performance was carefully investigated by optical instruments and equipment (n= 3). Thein vitroresults showed that TA (AZD0364/PTE) IOL can significantly inhibit cell adhesion and acute inflammation (n= 3,P< 0.0001). Importantly, afterin vivoimplantation for 28 d with eight rabbits PCO models in two groups, the TA (AZD0364/PTE) IOL group maintained clear refracting media and decreased the inflammatory reaction compared with the original IOL group (P< 0.05). This study provides a new applicable and economical strategy for preventing PCO and offers a reference for the next generation of IOLs that benefit cataract patients.

Intraocular pressure increase after Nd:YAG laser capsulotomy and anterior segment optical coherence tomography analysis

This study is to determine whether post-procedure intraocular pressure (IOP) increase is associated with the anterior chamber angle in cases of Neodymium: yttrium-aluminum garnet (Nd: YAG) laser capsulotomy. The study included 51 eyes with posterior capsule opacification. Initial IOP values of the patients were compared with IOP values without intraocular pressure-lowering administration at the end of the 1st hour, 1st day, 3rd day, and 7th day after Nd:YAG laser capsulotomy. The anterior segment angle configuration was evaluated using anterior segment optical coherence tomography analysis without dilatation before the procedure. The anterior chamber angle (ACA) and angle opening distances of 500 and 750 μm (AOD500 and AOD750) in the nasal and temporal quadrants were examined. The mean pre-laser IOP value only increased significantly at 1st hour post-laser (13.02 ± 3.02 mmHg vs 14.16 ± 4.07 mmHg, p = 0.016). In eyes with ACA below 40° in both the nasal and temporal quadrants, mean IOP increased significantly at 1st hour post-laser (p = 0.025 and p = 0.032, respectively), while it was not significant in eyes with ACA above 40° (p > 0.05). No correlation was found between ACA, AOD500, and AOD750 values and IOP changes at the first hour (p > 0.05). Except for the first hour after Nd:YAG laser capsulotomy, no significant increase in IOP was observed. This elevation was higher in eyes with ACA less than 40°. In patients with a narrow ACA, first-hour follow-up may be beneficial in terms of susceptibility to increased IOP.

Nd:YAG Laser Capsulotomy: Efficacy and Outcomes Performed by Optometrists

SIGNIFICANCE

An increasing number of optometrists are performing Nd:YAG laser capsulotomy procedures; however, there is limited published information on the outcomes of these procedures.

PURPOSE

This study aimed to assess the efficacy and safety of capsulotomy procedures performed by optometrists.

METHODS

Subjects diagnosed with posterior capsule opacification causing reduced vision and subjective visual complaints were recruited for this study. A baseline examination was performed to ensure that the subjects met all the necessary criteria. The procedure was performed by a licensed doctor of optometry at six different clinics, and each subject was monitored for visual outcome and any potential complications.

RESULTS

Subjects' Snellen visual acuity improved from an average of 20/40 to 20/23 ( P < .001) with no complications of increased intraocular pressure, inflammation, visually significant lens pitting, macular edema, or retinal detachment. Of 78 subjects who responded to a post-procedure survey, 77 (99%) reported subjective improvement in vision after capsulotomy.

CONCLUSIONS

Based on the outcomes of this study, YAG laser capsulotomies are effective treatments to improve patient vision that can be safely and effectively performed by optometrists.

The effect of Nd:YAG Laser applied in the posterior capsule opacification on retinal and choroidal structures

PURPOSE

To assess the effect of neodymium:yttrium-aluminum-garnet (Nd-YAG) laser procedure on the choroid and retina in patients who developed posterior capsular opacification (PCO) after cataract surgery.

METHODS

In this study, 32 eyes of 30 patients who underwent Nd:YAG laser treatment for PCO were evaluated. Visual acuity (VA), intraocular pressure (IOP), central macular thickness (CMT) with optical coherence tomography device (OCT), ganglion cell layer (GCL), inner plexiform layer (IPL), retinal nerve fiber layer (RNFL) and subfoveal choroidal thickness (SCT) were measured. Choroidal vascular index (CVI) was calculated from HD line images obtained by spectral domain OCT with the software Image J.

RESULTS

The mean age of the patients participating in the study was 60.1 ± 8.9 years. There was no significant difference in IOP, CMT, RNFL, GCL, IPL and SCT values ​​in all comparisons before and after laser (p>0.05 for all values). While Nd:YAG laser pretreatment CVI was 63.2 ± 3.2%, it was 66.8 ± 2.9% at 1 week and 67.1 ± 2.6% at 1 month after laser treatment. A significant difference was detected in the comparison of pre-laser CVI and post-laser 1 week and 1 month CVI (p<0.05 for all values).

DISCUSSION

CVI was found to be significantly higher in the post-laser period in patients who underwent Nd:YAG laser. As far as the author knows, this study is the first research in the literature to evaluate this relationship. CVI can be used to evaluate choroidal vascular changes after Nd:YAG laser.

The evaluation of the effect of Nd-YAG capsulotomy on posterior ocular vascular structures by Optical coherence tomography angiography

BACKGROUND

We aimed to examine the changes in retinal, choroidal and optic nerve head vascular structures after Nd-YAG laser application due to posterior capsule opacification after cataract surgery by Optical coherence tomography angiography (OCTA).

METHODS

Fifteen eyes of 15 patients who have posterior capsule opasification and underwent Nd-YAG laser capsulotomy were included in the study. OCTA imagings of patients were made before and one hour, one week and one month later after the laser procedure.

RESULTS

No significant change was determined before and after capsulotomy in macular thickness measurements, flow areas and vessel densities (all p > 0.05). Optic nerve head vessel densities and flow areas didn't differ preoperatively and postoperatively (p > 0.05).

CONCLUSIONS

Nd-YAG laser capsulotomy for posterior capsule opacification has no detectable effect on macular and optic nerve flows and vessel densities.

Evaluation of Nd:YAG laser capsulotomy results in patients who underwent cataract extraction and intraocular lens implantation with the endocapsular phacoemulsification method

Background/Aim: Posterior capsular opacification (PCO) is a common complication that develops after cataract surgery, and it can be treated neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy. In this study, we aimed to investigate the effects of different intraocular lenses (IOLs) on the development of posterior capsule opacification (PCO), to determine the time between surgery and Nd:YAG laser capsulotomy, and to evaluate the efficacy, effectiveness, and complications of capsulotomy in patients who underwent cataract surgery with the phacoemulsification method and subsequently developed PCO. Methods: The cohort study included one eye of each of 153 cases (63 males, 90 females) who underwent cataract surgery with the phacoemulsification method in our clinic from August 1, 2006, through August 1, 2008, and subsequently developed PCO. According to the type of IOL implanted, the cases were divided into three groups: polymethylmethacrylate IOL (Group 1), hydrophilic acrylic IOL (Group 2), and hydrophobic acrylic IOL (Group 3). The control examinations of the patients who underwent Nd:YAG laser capsulotomy were undertaken before capsulotomy and at the first week, first month, and third month after capsulotomy. Results: Visual acuity improvement was detected in 96.7% of the 153 cases. It was determined that 9.1% of the cases had an intraocular pressure (IOP) increase of more than 5 mmHg at the third hour after capsulotomy and approached baseline values at the end of 1 week. The mean   total energy used in all the cases was 37.20 (14.70) mjl. The mean total energy used in 14 patients with an IOP elevation of above 5 mmHg was 71.07 (10.59) mjl. Nd:YAG laser capsulotomy was performed at an average of 6.29 (4.91) months in Group 1, 7.81 (4.35) months in Group 2, and 17.7 (12.35) months in Group 3. After capsulotomy, clinically significant cystoid macular edema was observed in 1.9% of the cases, IOL damage in 3.9%, and vitreous hemorrhage in 0.6%. Conclusion: In this study, the incidence of PCO development was found to be lower in the patients who underwent hydrophobic acrylic IOL implantation; therefore, this type of lens should be preferred for implantation. Although Nd:YAG laser capsulotomy is an outpatient treatment method that can be applied quickly and can increase visual acuity, it can also lead to complications. To eliminate most of these complications, it would be beneficial to minimize the energy used during the laser procedure.

Refractive Changes After Nd:YAG Capsulotomy in Pseudophakic Eyes

Purpose

To analyze refractive changes after neodymium: yttrium-aluminum-garnet (Nd:YAG) posterior capsulotomy in pseudophakic eyes.

Patients and Methods

Patients who underwent Nd:YAG capsulotomy after cataract surgery from January 2013 to April 2022 were included in this retrospective study. Sphere, cylinder, spherical equivalent (SE), axis, and corrected distance visual acuity (CDVA) were compared pre- and postoperatively in 683 eyes of 548 patients at one month (n = 605 eyes) and one year (n = 211 eyes). Patients with both one-month and one-year follow-ups (n = 133) were also compared. Eyes were stratified into single-piece (n = 330), three-piece (n = 30), and light adjustable lenses (LALs) (n = 16). Pre- and postoperative measurements were analyzed within each group.

Results

Cylinder was significantly decreased at one-month (difference: 0.042±0.448 D, p = 0.006) and one-year (difference: 0.101±0.455 D, p = 0.003) compared to preoperative measurements. No significant change in sphere or axis was observed at follow-up visits (p > 0.05). CDVA significantly improved at both time points (p < 0.05). No significant change in any parameters between the one-month and one-year groups was observed (p > 0.05). There was significant improvement in CDVA in the single and three-piece lens groups (p < 0.0001 and p = 0.026, respectively), with no change in the LAL group (p > 0.05).

Conclusion

There were no changes in sphere, axis, or spherical equivalent after Nd:YAG capsulotomy. However, cylindrical error and CDVA were significantly better after the procedure. Lens type did not impact refractive parameters postoperatively.

Spin-Coating-Based Facile Annular Photodynamic Intraocular Lens Fabrication for Efficient and Safer Posterior Capsular Opacification Prevention

Posterior capsular opacification (PCO) is the most common complication after cataract surgery, which is primarily caused by the proliferation of the residual lens epithelial cells (LECs) in the lens capsule. Previous studies have demonstrated that a drug-eluting intraocular lens (IOL), aimed to in situ eliminate LECs, are an effective and promising way to prevent PCO. However, because of the potential toxicities of the antiproliferative drugs to the adjacent tissues, the safety of such drug-eluting IOLs is still a highly important issue to be solved. In this investigation, a facile photodynamic coating-modified IOL was developed for effective and safer PCO prevention. An annular poly(lactide-co-glycolic acid) (PLGA) coating loaded with photosensitizer chlorin e6 (Ce6) was prepared by a spin-coating technique. The optical property investigations showed that the Ce6@PLGA coating was particularly suitable for the IOL surface modification. The in vitro cell culture investigation showed that Ce6@PLGA coating-modified IOLs effectively eliminated LECs when treated with light illumination, whereas it appeared to have good cytocompatibility without irradiation. The investigation of the cell elimination mechanism showed that the apoptosis of HLECs may be associated with the cytomembrane disruption induced by ROS, which is generated by the photodynamic coating during light illumination. The in vivo implantation experiments confirmed the desired PCO prevention effect, as well as the safety to and biocompatibility with the surrounding tissues. Thus, the facile Ce6@PLGA coating will provide an effective yet safe alternative of IOL surface modification for PCO prevention.

Refraction Shift After Nd:YAG Posterior Capsulotomy in Pseudophakic Eyes: A Systematic Review and Meta-analysis

PURPOSE

To explore ocular refraction shift after Neodymium: yttrium aluminum garnet (Nd:YAG) posterior capsulotomy in pseudophakic eyes.

METHODS

A systematic literature search was performed in the PubMed, Embase, and Cochrane Library databases until November 10, 2021. Studies on the evaluation of changes in spherical equivalent (SE), cylindrical error (CE), or anterior chamber depth (ACD) after Nd:YAG laser capsulotomy were included in the meta-analysis. The review was registered in the international platform of registered systematic review and meta-analysis protocols (INPLASY202120059).

RESULTS

A total of 805 eyes from 18 studies were included in the final analysis. The pooled mean differences in SE from baseline to postoperative follow-up points were not significant (1 hour: 0.04 diopters [D], 95% CI: -0.13 to 0.21, P = .644; 1 week: 0.04 D, 95% CI: -0.12 to 0.20, P = .640; 1 month: 0.05 D, 95% CI: -0.06 to 0.16, P = .349). There was no significant difference between baseline CE and any subsequent visit (1 week: 0.14 D, 95% CI: -0.06 to 0.33, P = .172; 1 month: 0.17 D, 95% CI: -0.04 to 0.38, P = .108). No statistical difference in ACD from baseline was observed either (1 hour: 0.01 mm, 95% CI: -0.07 to 0.09, P = .846; 1 week: -0.12 mm, 95% CI: -0.24 to 0.01, P = .079; 1 month: -0.06, 95% CI: -0.14 to 0.01, P = .110).

CONCLUSIONS

Neither ocular refraction nor ACD changed within 1 month after laser capsulotomy, suggesting laser capsulotomy did not affect ocular refraction in short-term observation. [J Refract Surg. 2022;38(7):465-473.].

Sustained Release of Antibody-Conjugated DNA Nanocarriers from a Novel Injectable Hydrogel for Targeted Cell Depletion to Treat Cataract Posterior Capsule Opacification

Purpose: To compare a novel, sustained release formulation and a bolus injection of a targeted nanocarrier for the ability to specifically deplete cells responsible for the development of posterior capsule opacification (PCO) in week-long, dynamic cell cultures. Methods: A novel, injectable, thermosensitive poly(D,L-lactic-co-glycolic acid)-b-poly(ethylene glycol)-b-poly(D,L-lactic-co-glycolic acid) (PLGA-PEG-PLGA) triblock copolymer hydrogel was engineered for the sustained release of targeted, nucleic acid nanocarriers loaded with cytotoxic doxorubicin (G8:3DNA:Dox). Human rhabdomyosarcoma (RD) cells were used due to their expression of brain-specific angiogenesis inhibitor 1 (BAI1), a specific marker for the myofibroblasts responsible for PCO. Under constant media flow, nanocarriers were injected into cell cultures as either a bolus or within the hydrogel. Cells were fixed and stained every other day for 7 days to compare targeted depletion of BAI1⁺ cells. Results: The formulation transitions to a gel at physiological temperatures, is optically clear, noncytotoxic, and can release G8:3DNA:Dox nanocarriers for up to 4 weeks. In RD cell cultures, G8:3DNA:Dox nanocarriers specifically eliminated BAI1⁺ cells. The bolus nanocarrier dose showed significantly reduced cell depletion overtime, while the sustained release of nanocarriers showed increased cell depletion over time. By day 7, <2% of BAI1⁺ cells were depleted by the bolus injection and 74.2% BAI1⁺ cells were targeted by the sustained release of nanocarriers. Conclusions: The sustained release of nanocarriers from the hydrogel allows for improved therapeutic delivery in a dynamic system. This method can offer a more effective and efficient method of prophylactically treating PCO after cataract surgery.

Refractive Changes Following Premature Posterior Capsulotomy Using Neodymium:Yttrium–Aluminum–Garnet Laser

We aimed to determine the timing of neodymium:yttrium–aluminum–garnet (Nd:YAG) laser capsulotomy on corrected-distance visual acuity (CDVA), intraocular pressure (IOP), and spherical equivalent (SE) in patients with posterior capsular opacification (PCO). There were 59 patients with unilateral PCO and a history of Nd:YAG laser capsulotomy enrolled and further divided into the early Nd:YAG group (timing < 12 months, n = 25) and late Nd:YAG group (timing > 12 months, n = 34) depending on the elapsed months from phacoemulsification to Nd:YAG laser capsulotomy. The primary outcomes were CDVA, IOP, and SE before (immediately before Nd:YAG laser capsulotomy) and after (weeks one and four after the laser treatment). The independent t test was applied to analyze the difference in CDVA, IOP, and SE between the two groups, while the generalized estimating equation with Bonferroni adjustment was conducted to evaluate the effect of all the parameters on the change in SE with adjusted odds ratio (aOR) and 95% confidence interval (CI). The CDVA showed significant improvement in both the early Nd:YAG group (p = 0.005) and the late Nd:YAG group (p = 0.001), and hyperopic change occurred in both the early Nd:YAG group (p = 0.003) and the late Nd:YAG group (p = 0.017). The early Nd:YAG group revealed more significant hyperopic change compared with the late Nd:YAG group four weeks after Nd:YAG treatment (p < 0.001), which was still significant after multivariable analysis (aOR: 0.899, 95% CI: 0.868–0.930, p = 0.011). In addition, a deeper ACD (aOR: 0.764, 95% CI: 0.671–0.869, p = 0.019) was significantly correlated with hyperopic change. In conclusion, Nd:YAG laser capsulotomy performed within one year after cataract surgery may lead to significant hyperopic change, in which the ACD alteration affects the hyperopic shift significantly.

Centrifugally concentric ring-patterned drug-loaded polymeric coating as an intraocular lens surface modification for efficient prevention of posterior capsular opacification

Posterior capsular opacification (PCO) is the main postoperative complication after intraocular lens (IOL) implantation in cataract surgery, because of the proliferation of the residual lens epithelial cells (LECs) in the lens capsule. Drug-eluting IOLs, aimed to develop an in situ drug delivery device, are the promising concept in recent years. As IOLs are optical devices other than implants, the feasibility and applicability remain a challenge for drug-eluting coatings. In this investigation, a centrifugally concentric ring-patterned drug-loaded poly(lactide-co-glycolic acid) (PLGA) coating was designed and fabricated by the spin coating technique. The concentric ring-patterned morphologies and the drug loading and release properties were carefully investigated, and the spin coating parameters were optimized. A concentric annular coating with a thin center and thick periphery was obtained, which was particularly suitable for the surface modification of IOLs, as the visual pathway of the intraocular light transmission greatly requires good light transmittance of the IOLs. IOLs with the immunosuppressant cyclosporin A (CsA)-loaded coating (CsA @ PLGA) modification were then fabricated for PCO prevention. The in vitro LECs culture results showed that the CsA @ PLGA coating-modified IOLs significantly inhibited cell proliferation and induced cell death. Western blot analysis showed that the efficient cell inhibition behavior of CsA was due to the autophagy-mediated cell death pathway. The in vivo intraocular implantation results confirmed the desired PCO inhibition effect. Thus, the centrifugally concentric ring-patterned drug-loaded PLGA coating obtained by the spin coating technique provides a simple yet effective alternative of IOL modification for PCO prevention. STATEMENT OF SIGNIFICANCE: • Concentric ring-patterned polymer coating, specifically for drug-eluting IOL fabrication, was developed by the spin coating technique. • The immunosuppressant CsA inhibited LEC proliferation through the autophagy-mediated cell death pathway. • Concentric ring-patterned CsA-eluting IOLs exhibited reliable in vivo PCO prevention. • The drug-eluting IOLs fabricated by the simple and economical spin coating technique have a great potential in clinical translation.

Intraocular Lens Position and Anterior Chamber Parameters Evaluation After Nd:YAG Laser Posterior Capsulotomy for Posterior Capsular Opacification Using Anterior Segment Swept-Source Optical Coherence Tomography

Purpose

Patients and Methods

Results

Conclusion

Effect of misalignment at different orientations associated with angle κ on optical performance of aspheric intraocular lenses with different surface designs

Intraocular lens (IOL) misalignment and angle κ have had significant negative impact on post-operative quality of vision. ZEMAX software has been used to imitate the optical performance of pseudophakic eyes with different IOL surface designs at different orientations of IOL misalignment (decentration of 0.4 mm and tilt of 7°, and with the existence of 0.5 mm angle κ). We found that an aspheric balanced curve optic surface maintained better optical performance via inducing less coma aberration. Coma aberration played an unexpectedly important role in the optical performance. With angle κ, the impact of IOL misalignment on visual quality was associated with the orientation of decentration and tilt, indicating that the coma compensation also took effect in pseudophakic eyes. Due to the high incidence of post-operative IOL misalignment, our results provide evidence of the importance of considering personalized angle κ before cataract surgery for patients.

Impact of Neodymium-Doped Yttrium Aluminum Garnet (ND-YAG) Posterior Capsulotomy Laser Treatment on Central Macular Thickness: A Prospective, Observational Study From a Tertiary Care Center

Introduction

Opacification of the posterior capsule is labeled as a secondary cataract. The objective of the current study was to assess central macular thickness (CMT) changes following neodymium-doped yttrium aluminum garnet (ND-YAG) posterior capsulotomy and to find out the correlation between CMT with the age, energy, and total shots utilized during the procedure.

Methodology

In this single-centered prospective observational study, 137 patients with a mean age of 57 ± 12.61 years, who had cataract surgery previously and were candidates for ND-YAG posterior capsulotomy were recruited through consecutive sampling. The study was conducted at Layton Rahmatulla Benevolent Trust (LRBT) Free Eye Hospital, Township, Lahore, Pakistan, between April 2020 to April 2021. The CMT, total energy, and sum total of shots used were recorded. The thickness of the central macula was measured preoperatively and postoperatively after two weeks. The paired sample t-test was used to find out any significant changes in CMT pre and two weeks postoperatively. The comparison of changes in CMT to age, energy, and the total number of shots was made through Pearson correlation. Means of CMT were compared using an independent sample t-test, at two weeks postoperatively among two energy groups.

Results

No statistically significant differences were found between preoperative and two weeks postoperative values of the CMT (P-value= 0.209). No significant difference was found in CMT statistically among the two energy groups (p=0.11). The patient's age, sum total of laser shots, and aggregate of laser energy did not have any significant correlation with CMT changes. The time period between cataract surgery and ND-YAG surgery showed a moderately positive correlation with a p-value of 0.01.

Conclusion

The current study revealed that ND-YAG capsulotomy does not affect the CMT significantly postoperatively. The patient's age, total energy applied, and the total number of laser shots used do not influence the macular thickness. However, the length of duration from the last cataract surgery to the current surgery was significantly associated with a change in the CMT.

Posterior capsular opacification evaluation through contrast sensitivity defocus curves with two multifocal intraocular lenses of similar material

PURPOSE

To assess the degree of posterior capsular opacification (PCO) and its influence on contrast sensitivity defocus curve (CSDC) after implantation of two trifocal intraocular lenses (IOLs), Alsafit (AT) and Liberty (L), during a 12-month follow-up. A secondary aim was to evaluate the Nd:YAG capsulotomy rate in a long time.

METHODS

Data from 63 subjects, 34 implanted with AT and 29 with L, were retrospectively analyzed for this pilot study. In those eyes without capsulotomy during the first year (n = 58), CSDC at 3 and 12 months after surgery and PCO grading were measured, with additional answering of a visual function questionnaire (VF-14) and a question of general satisfaction. The period after surgery up to capsulotomy or last on-demand visit without Nd:YAG was recorded for survival analysis beyond the 12-month follow-up.

RESULTS

Total area under CSDC (TAUC) between 3 and 12 months decreased from 2.96 to 1.71 for AT (p < 0.05) and from 2.73 to 2.21 (p > 0.05) for L. Of eyes, 51.6, 19.3, and 29% with AT were graded as level 0, 1, and 2 of PCO, while 85.1, 11.1, and 3.7% of eyes with L were graded as level 0, 1, and 2 (p < 0.05). PCO grading was correlated with a decrease of TAUC (ρ =  - 0.27, p = 0.04). Median time to require capsulotomy was 22 months with AT and 30 months with L (p < 0.05).

CONCLUSIONS

PCO decreases CSDC in patients with trifocal lenses. Despite using the same hydrophilic material, PCO grading and Nd:YAG capsulotomy rate was higher for AT than for L.

Changes of intraocular lens position induced by Nd:YAG capsulotomy

AIMS

The aim of this study was to evaluate the changes in IOL position (axial shift, tilt and decentration) in the capsular bag after Nd:YAG laser capsulotomy and to create a user-friendly software that is optimized for the output of available imaging technology, then verify the relationship between the biometric parameters of the eye and the extent of changes in the IOL position.

PATIENTS AND METHODS

The study included 35 artephakic eyes that underwent laser capsulotomy. Before and at least one hour after capsulotomy, all patients underwent the following assessments: optical biometry (Lenstar LS900), OCT with anterior segment module (Optovue Avanti) and IOL photography in infrared mode using reference unit (Verion). The original software solution was designed for the graphical evaluation of the differences between centering, axial displacement and tilt of IOL. Changes in IOL position were evaluated as simple differences before and after the laser procedure and as differences in absolute values (abs).

RESULTS

The following results show the average differences in IOL position: ACD=0.02±0.23 mm (abs=0.11±0.20 mm), IOL decentration in x-axis = -0.001±0.091 mm (abs=0.065±0.063 mm), IOL decentration in y-axis =0.012±0.119 mm (abs=0.048±0.53 mm), tilt in horizontal plane TILT-H=0.11±0.83° (abs=0.51±0.66°) and tilt in vertical plane TILT-V = -0.14±0.49° (abs=0.26±0.44°). All changes were insignificant (P>>0.05). In total, 74.29% of IOLs showed a hypermetropic shift. A moderate positive correlation was found between the absolute differences in horizontal tilt and keratometry (r=0.45). Relationship with other changes and parameters were weak.

CONCLUSION

In conclusion, the use of the original software solution developed by the authors showed that changes in IOL centering, axial displacement and tilt occur after Nd:YAG capsulotomy, but average differences were insignificant. In almost 3/4 cases, there was a hypermetropic axial displacement of the IOL.

Study of Intraocular Pressure following Neodynium Yttrium Aluminium Garnet Laser Capsulotomy with the Use of Brimonidine: A Descriptive Cross-sectional Study

Introduction:

Posterior capsular opacification is a common complication after cataract surgery. Neodynium Yttrium Aluminium Garnet laser capsulotomy is still the preferred treatment for posterior capsular opacification. This study was done to determine the use of Brimonidine eye drop in preventing the rise of intraocular pressure post-Neodynium Yttrium Aluminium Garnet laser capsulotomy.

Methods:

A descriptive cross-sectional study was conducted in Lumbini eye institute and research center, Bhairahawa, Nepal, in 200 eyes with posterior capsular opacification using Brimonidine from Feb 1, 2019, to July 30, 2019. The Institutional Review Committee approved the study with approval number 0237. A convenient sampling method was used. Pre-capsulotomy best-corrected visual acuity, slit-lamp examination of the anterior segment, and dilated fundus examination were done. Intraocular pressure was measured with Goldmann Applanation Tonometer. Post capsulotomy patients were evaluated after one hour, two hours, and two weeks for intraocular pressure and any complications. The statistical analysis was done using Statistical Package of Social Sciences version 20.0 statistical analysis software. The descriptive statistical analysis of the study was done after the collection of the data.

Results:

Mean age of patients at presentation was 61.61 ±SD 1.09. The mean intraocular pressure following Neodynium Yttrium aluminum garnet laser capsulotomy using brimonidine at 1 hour was 12.73±3.3 mmHg. and two hours was 11.98±3.2 mmHg. The mean energy per pulse was 2.3 ±SD 0.3 mJ. The mean duration of posterior capsular opacification from cataract surgery was 22.28 weeks.

Conclusions:

Neodynium Yttrium Aluminium Garnet laser capsulotomy had lower intraocular pressure after the Brimonidine eye drop procedure. The maximum mean reduction in intraocular pressure was observed after two hours.

Supercritical fluid technology for the development of innovative ophthalmic medical devices: Drug loaded intraocular lenses to mitigate posterior capsule opacification

Supercritical impregnation technology was applied to load acrylic intraocular lenses (IOLs) with methotrexate to produce a sustained drug delivery device to mitigate posterior capsule opacification. Drug release kinetics were studied in vitro and used to determine the drug loading. Loaded IOLs and control IOLs treated under the same operating conditions, but without drug, were implanted ex vivo in human donor capsular bags. The typical cell growth was observed and immunofluorescence staining of three common fibrosis markers, fibronectin, F-actin and α-smooth muscle actin was carried out. Transparent IOLs presenting a sustained release of methotrexate for more than 80 days were produced. Drug loading varying between 0.43 and 0.75 ± 0.03 µg_drug·mg^-1_IOL were obtained when varying the supercritical impregnation pressure (8 and 25 MPa) and duration (30 and 240 min) at 308 K. The use of ethanol (5 mol%) as a co-solvent did not influence the impregnation efficiency and was even unfavorable at certain conditions. Even if the implantation of methotrexate loaded IOLs did not lead to a statistically significant variation in the duration required for a full cell coverage of the posterior capsule in the human capsular bag model, it was shown to reduce fibrosis by inhibiting epithelial-mesenchymal transformation. The innovative application presented has the potential to gain clinical relevance.