The Effect of ND:YAG Laser Posterior Capsulotomy Size on Refraction, Intraocular Pressure, and Macular Thickness

Evaluation of Methods for Detection and Semantic Segmentation of the Anterior Capsulotomy in Cataract Surgery Video

Background

The capsulorhexis is one of the most important and challenging maneuvers in cataract surgery. Automated analysis of the anterior capsulotomy could aid surgical training through the provision of objective feedback and guidance to trainees.

Purpose

To develop and evaluate a deep learning-based system for the automated identification and semantic segmentation of the anterior capsulotomy in cataract surgery video.

Methods

In this study, we established a BigCat-Capsulotomy dataset comprising 1556 video frames extracted from 190 recorded cataract surgery videos for developing and validating the capsulotomy recognition system. The proposed system involves three primary stages: video preprocessing, capsulotomy video frame classification, and capsulotomy segmentation. To thoroughly evaluate its efficacy, we examined the performance of a total of eight deep learning-based classification models and eleven segmentation models, assessing both accuracy and time consumption. Furthermore, we delved into the factors influencing system performance by deploying it across various surgical phases.

Results

The ResNet-152 model employed in the classification step of the proposed capsulotomy recognition system attained strong performance with an overall Dice coefficient of 92.21%. Similarly, the UNet model with the DenseNet-169 backbone emerged as the most effective segmentation model among those investigated, achieving an overall Dice coefficient of 92.12%. Moreover, the time consumption of the system was low at 103.37 milliseconds per frame, facilitating its application in real-time scenarios. Phase-wise analysis indicated that the Phacoemulsification phase (nuclear disassembly) was the most challenging to segment (Dice coefficient of 86.02%).

Conclusion

The experimental results showed that the proposed system is highly effective in intraoperative capsulotomy recognition during cataract surgery and demonstrates both high accuracy and real-time capabilities. This system holds significant potential for applications in surgical performance analysis, education, and intraoperative guidance systems.

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.

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.

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.

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.].

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.

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.

Influence of the "Inverted U Method" Nd: YAG Laser Posterior Capsulotomy on Anterior Segment Parameters, Decentration and Tilt of Intraocular Lens in Patients after Phaco-vitrectomy

PURPOSE

To investigate the effects of the "inverted U method" Nd:YAG laser posterior capsulotomy on anterior segment parameters, decentration and tilt of intraocular lens (IOLs) and visual acuity in posterior capsular opacification (PCO) patients after combined phaco-vitrectomy.

METHODS

Seventy-six patients (76 eyes) were enrolled in this study, who were diagnosed as PCO and underwent "inverted U method" Nd:YAG laser posterior capsulotomy. All patients had undergone previous combined phaco-vitrectomy for rhegmatogenous retinal detachment. The parameters including IOL decentration, angle of IOL tilt, anterior chamber angle (ACA), anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness (CCT), keratometry, pupil size, axial length (AL), intraocular pressure (IOP), refractive status, corrected distance visual acuity (CDVA), objective scattering index (OSI) and Chinese version of Visual Function 14 (VF-14) index were obtained before and 3 months after capsulotomy.

RESULTS

After capsulotomy, the tilt angle and decentration of the IOLs at both vertical (tilt: p = .004, decentration: p = .029) and horizontal meridian (tilt: p = .001, decentration: p = .017) were significantly decreased, ACA increased (p = .015), CDVA (p = .000), VF-14 score (p = .000) and OSI (p = .000) were significantly improved. There were a significant decrease in cylindrical error (p = .001) and a myopic shift in spherical error (p = .001) after the capsulotomy. No significant differences in ACD, ACV, CCT, keratometry, pupil size, AL and IOP were detected (p > .05 for all).

CONCLUSION

The "inverted U method" Nd: YAG laser posterior capsulotomy decreases tilt and decentration of the IOL, increases ACA and causes no change in ACD, ACV, CCT and IOP in patients after phaco-vitrectomy. These changes make a decrease in cylindrical error and a myopic shift in spherical error. Laser capsulotomy significantly improves visual acuity.

Budget impact analysis of lens material on the posterior capsule opacification (PCO) as a complication after the cataract surgery

Background

Over 300,000 cataract operations are performed in Poland every year, and the most common, late complication of cataract removal surgery is posterior capsule opacification (PCO). The risk of PCO depends on the lens material. Hydrophobic acrylic lenses cause PCO less frequently as lymphatic endothelial cells show lower affinity for the surface of the lens made of silicone. The objective of this study is to assess the economic impact of using hydrophobic acrylic lenses compared to using hydrophilic acrylic lenses for cataract treatment in the Polish inpatient and outpatient settings.

Methods

A budget impact analysis (BIA) compared the economic outcomes associated with using hydrophobic acrylic lenses versus using hydrophilic lenses for patients undergoing cataract surgery. The BIA predicted annual expenses in the following scenarios: performing Nd:YAG to treat PCO within 2 and 3 years after implantation of hydrophobic or hydrophilic acrylic lenses for different lens structure. Data used to assess the frequency of PCO was determined in systematic literature review. Costs of current and predicted interventions were estimated based on average data from 19 Polish hospitals. Prices of health services were taken from official public tariff lists.

Results

The use of a hydrophobic lens significantly limits the number of complications after cataract surgery relative to a hydrophilic lens. As hydrophobic lenses have a higher unit price their use increases the cost of treatment which currently is not reflected by adequate difference in price of the service. Total annual National Health Fund (NHF) expenses for 3-year follow-up model range from 139.1 million EUR to 143.1 million EUR depending on the lens structure, due to the cost of complications.

Conclusions

BIA indicates the possibility of introducing surcharge for the use of hydrophobic lenses, which could increase the frequency of their use and reduce the number of complications after cataract surgery. It was estimated that total NHF expenses reach the minimum value for the surcharge at the level of 9 EUR. The surcharge of 14 EUR is the maximum value that does not increase the initial NHF expenses.

[Combined vitrectomy-lensectomy surgery with bag-in-the-lens or lens in the bag implantation: comparison of final visual acuity]

INTRODUCTION

Combined vitrectomy-lensectomy surgery is a safe and effective procedure. Nevertheless, it is frequently complicated by posterior capsule opacification and the formation of posterior synechiae. These complications can be avoided by placing a "bag in the lens" (BIL) implant. The objective of this study is to compare the visual acuity gain (VA) after combined vitrectomy-lensectomy surgery between a group implanted with the BIL technique and a group with implantation in the bag (LIB).

MATERIAL AND METHODS

We included in the study all vitrectomy-lensectomy procedures for epiretinal membrane and vitreomacular traction performed between May 2013 and July 2016 at the Hospital and University Center of Caen. We compared the VA gain between the BIL group and the LIB group six months after surgery.

RESULTS

A total of 33 patients were included in the study, consisting of 28 eyes in the BIL group and 8 eyes in the LIB group. The mean VA gain in the BIL group was -0.52 LogMAR (P<0.0001) and -0.56 LogMAR (P=0.0047) for the LIB group. The difference between the two groups was not significant (P=0.74).

CONCLUSION

The use of the BIL technique during vitrectomy-lensectomy allows visual recovery as good as implantation within the capsular bag. In addition, this implant has the advantage of significantly reducing the occurrence of posterior synechiae and preventing anterior and posterior capsular proliferation.

[Retinal changes after laser interventions on anterior segment of the eyeball]

Laser surgery of the cornea, iris, angle of the anterior chamber and other parts of anterior segment of the eye sees wide application in clinical practice. The adverse effects it can cause in the anterior segment are well known and understood. At the same time, changes the treatment method can cause in the posterior segment of the eye - primarily, in macular area of the cornea, which is of great importance, have not been studied sufficiently. Purpose of the review - to consolidate previously published data on changes in the retina after laser intervention on the anterior segment of the eye.

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

Purpose: To see the effect of Nd:YAG laser capsulotomy on intraocular pressure (IOP), refraction, best-corrected visual acuity (BCVA), anterior chamber depth (ACD), and macular thickness.

Methodology: The authors conducted a prospective, descriptive study on pseudophakic eyes with posterior capsule opacification who underwent Nd:YAG laser capsulotomy. BCVA, IOP, spherical equivalent (SE), macular thickness, and ACD were noted preoperatively, at 1 hr postoperatively and at 1-month follow-up. Patients were divided into two groups based on energy used (Group I ≤50 mJ, Group II >50 mJ). None of the patients received prophylactic antiglaucoma medications either before or after the procedure.

Results: There were 96 eyes of 83 patients. Mean total energy levels were 26.64±12.92 mJ in Group I and 81.96±32.10 mJ in Group II. BCVA at 1 hr and 1 month postoperatively improved significantly in both the groups compared to preoperative BCVA (P<0.001). There was no significant change in SE compared to preoperative values in both the groups. The ACD continued to increase significantly in both the groups at both 1 hr and 1-month follow-up. In Group I, IOP increased at 1 hr postoperatively (P=0.023) and declined to preoperative levels at 1 month. In Group II, IOP increased at 1 hr postoperatively (P<0.001) and did not return to preoperative levels at 1-month follow-up (P=0.003). Likewise, macular thickness increased at 1 hr in both groups (P<0.001). In Group I, macular thickness decreased significantly to preoperative level at 1 month whereas in Group II, it remained significantly high at 1-month follow-up (P=0.006). There was no case with serious rise in IOP or cystoid macular edema.

Conclusion: Statistically significant increment in IOP and macular thickness occurs after Nd:YAG laser capsulotomy which however may not necessitate the use of any medications.

FREQUENCY OF ACUTE RISE OF INTRAOCULAR PRESSURE FOLLOWING YAG LASER POSTERIOR CAPSULOTOMY

Background: Posterior capsular opacification (PCO) is the most frequent complication of cataract surgery. The objective of this study was to determine the frequency of acute rise of intraocular pressure (IOP) following Neodymium-Yttrium Aluminum Garnet (Nd:Yag) laser posterior capsulotomy. Materials & Methods: This cross-sectional study was conducted in the Department of Ophthalmology, HMC, Peshawar, Pakistan, from July-December 2016. Sample size was 325 selected by consecutive sampling technique. Inclusion criteria were all patients having significant PCO after uneventful cataract surgery with intra ocular lens implant. Demographic variables were sex, age groups and age in years. Research variable was presence of acute rise of IOP following Yag laser capsulotomy. Pre-laser assessment included slit lamp examination and recording of IOP with Goldmann applanation tonometer by a single ophthalmologist. IOP was measured 3 hours after Nd: Yag laser capsulotomy. Rise in IOP was labeled when IOP was ≥5 mmhg from baseline. Mean ±SD was used to express quantitative variables like age. Categorical variables were analyzed as frequency and percentage. Goodness-of-fit was applied to compare the frequency of acute rise in IOP between sample and population. SPSS-20 was used for data entry and its analysis. Results: Out of 325 patients, 170(52.3%) were men and 155(47.7%) were women. The mean age of the sample was 44.92 ±23.843 years. A total of 107(32.9%) patients were 20-39 years old whereas 218(67.1%) were 40-70 years. IOP was raised in 61 (18.8%) patients while in 264(81.2%) patients it was not raised. The frequency of acute rise in IOP after Yag laser capsulotomy was significantly different in sample compared to population. Conclusion: Men were more than women, especially of old age. The frequency of acute rise in IOP after Yag laser capsulotomy was significantly different in sample compared to population.

Long-term effectiveness and safety of a three-piece acrylic hydrophobic intraocular lens modified with hydroxyethyl-methacrylate: an open-label, 3-year follow-up study

Background

Clareon^® is a new hydrophobic acrylic optic biomaterial designed for enhanced clarity and greater resistance to glistening. The present study evaluated the effectiveness and safety of a three-piece hydrophobic, monofocal intraocular lens (IOL) Model MA60NM, made of this new optic material.

Methods

In this prospective, multicenter, open-label study, eligible patients aged ≥60 years, underwent a unilateral implantation with IOL Model MA60NM following phacoemulsification. Patients were followed-up for up to 3 years after implantation. Visual outcome and serious adverse events (SAEs, cumulative and persistent) were compared to ISO grid rates (BS EN ISO 11979-7:2006). The primary effectiveness variable was Best Spectacle-Corrected Visual Acuity (BSCVA) at 1-year postoperative follow-up. In addition, posterior capsular opacification (PCO) was assessed qualitatively and graded by slit lamp exam on a 5-point scale at all visits.

Results

Overall, 179 and 138 patients completed the 1-year and 3-year postoperative follow-up, respectively. The BSCVA outcomes were better with IOL Model MA60NM than the ISO grid rates with 95.5% of patients at 1 year and 94.2% of patients at 3 years having achieved a BSCVA of 20/40 or better vs 92.5% in ISO grid. The incidence of cumulative or persistent SAEs was lower after Model MA60NM implantation than the ISO grid reference. The incidence of clinically significant PCO was 1.1% at the 1-year and 2.2% at the 3-year visit. Posterior capsulotomy rate was 1.1% at 1 year and 1.4% at 3 years.

Conclusion

The three-piece hydrophobic, monofocal IOL Model MA60NM was effective for the visual correction of aphakia and successfully met all the safety parameters as defined by the ISO criteria. PCO and posterior capsulotomy rates were low over the 3-year follow-up period. This study provides evidence and supports the long-term safety and effectiveness of the new optic biomaterial Clareon^®.

Comparative study of induced changes in effective lens position and refraction after Nd:YAG laser capsulotomy according to intraocular lens design

Purpose

To evaluate and compare the changes in refraction and effective intraocular lens (IOL) position between a plate-haptic IOL and a c-loop single-piece IOL after neodymium-doped yttrium aluminium garnet (YAG) laser posterior capsulotomy.

Methods

In a prospective study, anterior chamber depth and subjective refraction were measured in 110 pseudophakic eyes from 110 patients, before and 1 month after YAG laser capsulotomy. Patients were divided into 2 groups according to the IOL design: group 1 (plate-haptic acrylic hydrophilic AT LISA tri 839MP^®) and group 2 (c-loop acrylic hydrophobic single-piece AcrySof^® SA60AT). Lens position was obtained through optical coherence biometry (Biograph WaveLight OB820^®).

Results

YAG laser capsulotomy was performed 37.8±9.8 months after surgery in group 1 and 40.6±8.6 months in group 2 (p=0.125). Significant changes were found in the lens effective position after treatment in the 2 groups. The YAG posterior capsulotomy led to a change of anterior chamber depth in group 1 from 4.03±0.32 mm to 3.86±0.34 mm (p=0.02) and in group 2 from 4.03±0.37 mm to 4.14±0.45 mm (p=0.025). After YAG laser posterior capsulotomy, no significant changes were observed in mean spherical equivalent, sphere or cylinder for both groups (p>0.05).

Conclusion

YAG laser posterior capsulotomy can induce a significant change in the IOL position according to the IOL type; however, the refractive change after treatment is clinically insignificant.

Comparison of two Nd:YAG laser posterior capsulotomy: cruciate pattern vs circular pattern with vitreous strand cutting

AIM

To investigate the effects and safety of neodymium: yttrium-aluminium-garnet (Nd:YAG) laser posterior capsulotomy with vitreous strand cutting.

METHODS

A total of 40 eyes of 37 patients with symptomatic posterior capsular opacity (PCO) were included in this prospective randomized study and were randomly subjected to either cruciate pattern or round pattern Nd:YAG posterior capsulotomy with vitreous strand cutting (modified round pattern). The best corrected visual acuity (BCVA), intraocular pressure (IOP), refractive error, endothelial cell count (ECC), anterior segment parameters, including anterior chamber depth (ACD) and anterior chamber angle (ACA) were measured before and 1mo after the laser posterior capsulotomy.

RESULTS

In both groups, the BCVA improved significantly (P<0.001 for the modified round pattern group, P=0.001 for the cruciate pattern group); the IOP and ECC did not significantly change. The ACD significantly decreased (P<0.001 for both) and the ACA significantly increased (P=0.001 for the modified round pattern group and P=0.034 for the cruciate group). The extent of changes in these parameters was not significantly different between the groups.

CONCLUSION

Modified round pattern Nd:YAG laser posterior capsulotomy is an effective and safe method for the treatment of PCO. This method significantly changes the ACD and ACA, but the change in refraction is not significant. Modified round pattern Nd:YAG laser posterior capsulotomy can be considered a good alternative procedure in patients with symptomatic PCO.

German claims data analysis to assess impact of different intraocular lenses on posterior capsule opacification and related healthcare costs

Aim

Cataract extraction is one of the most frequent surgeries in Germany. In most cases, the clouded natural lens is replaced by a hydrophobic or hydrophilic acrylic intraocular lens (IOL) implant. The most common long-term complication after cataract surgery is the development of a posterior capsule opacification (PCO). Although no precise real world data are available, published evidence suggests a lower risk for PCO development for hydrophobic acrylic IOLs compared to hydrophilic acrylic IOLs. Therefore, in the present study we assessed real world data on the impact of different IOL material types on the incidence of post-operative PCO treatment.

Subject and methods

In this retrospective study, we included 3,025 patients who underwent cataract extraction and implantation of either an acrylic hydrophobic or hydrophilic IOL in 2010. We assessed clinical outcomes and direct costs in a 4-year follow-up period after cataract surgery from a statutory health insurance (SHI) perspective in Germany.

Results

PCO that required capsulotomies occurred significantly (p < 0.0001) less frequent in patients who had received a hydrophobic IOL (31.57% of 2,078 patients) compared to the group with hydrophilic IOL implants (56.6% of 947 patients) and costs per patient for postoperative treatment in a 4-year follow-up were 50.03 € vs. 87.81 € (i.e. 75% higher in the latter group, p < 0.0001).

Conclusion

Considering the high prevalence of cataract, the economic burden associated with adverse effects of cataract extraction is of great relevance for the German SHI. Hydrophobic lenses seem to be superior regarding both medical and economic results.

Resident-performed neodymium:YAG laser posterior capsulotomy

OBJECTIVE

To investigate the outcomes of resident-performed Nd:YAG laser posterior capsulotomy.

DESIGN

Combined retrospective and prospective study.

PARTICIPANTS

Patients (N = 301) who underwent Nd:YAG capsulotomy by ophthalmology residents at Rassoul Akram Hospital, Tehran, Iran.

METHODS

Assessment of visual outcomes and complications and the results of second- and third-year residents.

RESULTS

In the retrospective arm, 131 eyes of 129 patients were enrolled. Mean best-corrected visual acuity (BCVA) improved significantly from 1.15 ± 0.26 to 0.54 ± 0.39 logMAR (p < 0.001). Mean intraocular pressure (IOP) before capsulotomy and at the final visit was 13.1 ± 2.34 mm Hg and 13.6 ± 2.17 mm Hg, respectively (P = 0.30). Retinal detachment occurred in 2 eyes (1.5%). No case of intraocular lens decentration or endophthalmitis was detected. In the prospective arm on 173 eyes of 172 patients, mean pre-YAG BCVA was 1.14 ± 0.25 logMAR and increased to 0.51 ± 0.37 logMAR after surgery (p < 0.001). There was no significant difference between pre-laser IOP measurements compared with the 1-month IOP measurements (P = 0.32). The postoperative changes in mean BCVA and IOP between the second- and third-year residents were not significant; however, the applied laser power, the number of laser spots, rate of incomplete capsulotomies, and the amount of total and central laser-induced IOL pits were significantly higher among the second-year residents.

CONCLUSIONS

Resident-performed capsulotomy appears to be effective with a low complication profile. Despite the lower levels of surgical skills, second-year residents could achieve good visual outcomes. The laser parameters and IOL-related complications improved with increasing surgical experience.

Study of Variation in Intraocular Pressure Spike (IOP) Following Nd- YAG Laser Capsulotomy

INTRODUCTION

Posterior Capsular Opacifications (PCO) is a frequent complication of cataract surgery following posterior chamber intraocular lens implantation. Nd -Yag laser capsulotomy is the treatment of choice for PCO and is known to be associated with complications like Raised Intraocular Pressure (IOP), Intraocular lens pitting, intraocular lens cracks, cystoid macular oedema, retinal detachment, corneal burns. Raised IOP is the most common complication and prescribing anti-glaucoma drugs post capsulotomy is a common practise. Our study helps us to anticipate the post procedural IOP rise in specific patients and treat only selected group of patients with anti- glaucoma medications.

AIM

To study and correlate the effect of energy used and number of shots with post procedural IOP spike following Nd-YAG laser capsulotomy cases.

MATERIALS AND METHODS

All patients with PCO presenting to Ophthalmology Out Patient Department at Sri Siddhartha Medical College between November 2014 to November 2015 were included. All the patients with glaucoma, uveitis and high myopia were excluded from the study. Data relevant to history, ocular examination and IOP were recorded.

RESULTS

Significant correlation of IOP spike with the number of Nd- YAG Laser shots delivered was found by One-way ANOVA Post-Hoc Tukeys Test. The p-value was significant for shots more than 40, provided the energy was restricted to 20 mJ and below. Correlation of energy with IOP spike was not significant as found by One-way ANOVA, Post-Hoc Tukey test. Predictability of 2 hours post-procedure IOP regarding persistent IOP rise was significant.

CONCLUSION

It was observed that all pseudophakic patients may not require anti-glaucoma medication pre, or post Nd YAG laser capsulotomy. Only patients who required more than 40 shots during the procedure would need a close observation and if persistent rise is documented, ocular hypotensives may be advised.

Neovascular glaucoma following Nd:YAG laser capsulotomy in a patient with diabetes and syphilitic uveitis

A diabetic woman had been suffering from progressively blurry vision in the right eye for 1 year after cataract surgery. Slit lamp examination revealed bilateral band keratopathy with quiescent anteriorchamber reaction, an intumescent cataract in the left eye, and dense posterior capsular opacity in the right eye. Capsulotomy was performed, but this led to neovascular glaucoma. Because of a refractory elevation in intraocular pressure, trabeculectomy with mitomycin C treatment, vitrectomy with panretinal photocoagulation, and intravitreal injection of bevacizumab were performed. A positive rapid plasma reagin test and a positive Treponema pallidum hemagglutination assay led to the impression of syphilitic uveitis, and the patient was treated with intravenous penicillin for 2 weeks. The visual acuity of the right eye was 0.1 at the 12^th-month follow up. This case shows that neovascular glaucoma may present as a complication of capsulotomy in uveitic/diabetic eyes.

Neodymium-yttrium aluminium garnet laser capsulotomy energy levels for posterior capsule opacification

Purpose:

To study factors affecting laser energy levels required for neodymium: yttrium aluminium garnet (Nd: YAG) laser capsulotomy and to evaluate whether any correlation exists between applied laser energy levels and complications.

Methods:

The present study examined 474 consecutive patients for a number of factors including age, type of posterior capsule opacification (PCO), material and fixation of intraocular lens (IOL) and complication rates, versus energy levels used for Nd: YAG laser capsulotomy.

Results:

Mean patient age was 55.6 ± 8.7 years and mean follow up period was 22.9 ± 4.5 months. IOL biomaterial (KW ANOVA; P = 0.173) and patient's age (P = 0.246) did not significantly influence total laser energy requirement for capsulotomy. However, total laser energy levels were significantly higher (KW ANOVA; P < 0.001) with fibro-membranous and fibrous subtypes of PCO. Complications such as IOL pitting, intraocular pressure (IOP) elevation, uveitis, retinal detachment (RD) and cystoid macular edema (CME) were significantly more common when higher energy levels was used. The mean total energy in patients with RD was 77.7 ± 17.7 mJ as compared to 43.4 ± 26.9 mJ in the rest of the cohort. RD was more common in patients with higher axial length [n = 7 (63%)] (P < 0.001).

Conclusion:

Type of PCO significantly influenced laser energy levels required for capsulotomy, whereas IOL biomaterial and fixation did not. Complications such as IOL pitting, uveitis, IOP elevation, RD and CME was significantly more common when total laser energy was higher. It is recommended that the lowest possible single pulse laser energy be used for capsulotomy to minimize complications.

The assessment of changes in macular thickness in diabetic and non-diabetic patients: the effect of topical ketorolac on macular thickness change after ND:YAG laser capsulotomy

PURPOSE

The purpose of our study is to assess the changes in macular thickness (MT) in diabetic and non-diabetic patients and to research effects of topical ketorolac (Acular®, Allergan, Irvine, CA) on MT change after neodymium:yttrium aluminum garnet (Nd:YAG) laser capsulotomy.

MATERIAL AND METHODS

This study involved 88 eyes of 88 patients diagnosed as posterior capsule opacification (PCO). Patients were divided into four groups according to presence of diabetes mellitus (DM) and drugs used after capsulotomy. Group 1: Patients with DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy (22 patients). Group 2: Patients with DM using 0.5% ketorolac (Acular®) and 0.1 Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy (20 patients). Group 3: Patients without DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) (22 patients). Group 4: Patients without DM using 0.5% ketorolac (Acular®) and 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) (24 patients). A plus-shaped capsulotomy was performed using VISULAS® YAGIII (Carl Zeiss) laser microscope. MT measurement with Cirrus SD-OCT (Carl Zeiss Opthalmic System Inc., Model 400, Dublin, CA, Software 5) were done. Measurements were done before laser, and on the first day, first week, first month, third month and sixth month after laser capsulotomy. We compared the four groups for MT change during 6 months.

RESULTS

Group 1 involving patients with DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy had increased MT at the first week, and the first, third, and sixth month after laser (p < 0.001). Group 3 involving patients without DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) had increased MT at the first week, and at the first and third month, there was no statistically significant difference at the sixth month (p > 0.05). There was no statistically significant increase in MT during the follow-up period in group 2 involving patients with DM using 0.5% ketorolac (Acular®) and 0.1 Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy and group 4 involving patients without DM using 0.5% ketorolac (Acular®) and 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) (p > 0.05).

CONCLUSION

An increase in MT can be observed after Nd:YAG laser capsulotomy, especially in diabetic patients. Adding topical ketorolac (Acular®, Allergan, Irvine, CA) to topical Fluorometholon (FML®, Allergan, Irvine, CA) therapy after YAG laser capsulotomy can prevent this increase.

An Overview of Nd:YAG Laser Capsulotomy

It has been revealed that posterior capsule opacification (PCO) is the most common delayed complication of cataract surgery. On the other hand, Nd:YAG laser capsulotomy is accepted as standard treatment for PCO. Although, Nd:YAG laser capsulotomy is a noninvasive and safe treatment it carries risk of some complications. Using less total energy and performing smaller capsulotomies are effective choices to decrease complications after Nd:YAG capsulotomy. The purpose of this review is to look through the complications associated with Nd:YAG laser capsulotomy, and the effect of capsulotomy size and used total energy on such complications.