The effect of single-piece hydrophobic acrylic intraocular lenses on the development of posterior capsule opacification

Effectiveness of prophylactic capsular tension ring implantation during cataract surgery in highly myopic eyes

PURPOSE

To assess the effectiveness of prophylactic capsular tension ring (CTR) implantation during cataract surgery in highly myopic eyes.

SETTING

Eye and Ear, Nose, and Throat Hospital of Fudan University, Shanghai, China.

DESIGN

Prospective cohort study.

METHODS

Consecutive highly myopic patients treated with cataract surgery were recruited and randomized to undergo CTR implantation or not. The outcomes compared between the 2 groups included axial lens position (ALP), intraocular lens (IOL) decentration and tilt, area of anterior capsule opening, severity of anterior capsular opacification (ACO), and posterior capsular opacification (PCO) at 1 year postoperatively.

RESULTS

A total of 55 highly myopic eyes with CTRs implanted and 55 without were included in the analysis. At 1 year postoperatively, no significant differences were detected between the CTR and non-CTR groups for the mean ALP, IOL decentration, or tilt (all P > .05). However, the CTR group had a significantly larger area of anterior capsule opening (23.62 ± 3.30 mm2 vs 21.85 ± 2.30 mm2, P = .003), and less severe ACO (P = .033) and PCO (PCO-3 mm: 0.06 ± 0.13 vs 0.13 ± 0.20, P = .038; PCO-C: 0.15 ± 0.18 vs 0.25 ± 0.26, P = .026) than the non-CTR group. The corrected distance visual acuity, prediction error, and higher-order aberrations did not differ between the 2 groups (all P > .05).

CONCLUSIONS

In highly myopic eyes, although prophylactic CTR implantation can reduce the severity of capsular contraction and opacification, it does not significantly affect postoperative IOL stability or visual outcomes.

Long-Term Outcomes of Posterior Capsular Opacification in Highly Myopic Eyes and Its Influencing Factors

INTRODUCTION

The purpose of this study was to evaluate the long-term outcomes of posterior capsular opacification (PCO) in highly myopic eyes and its influencing factors.

METHODS

Patients undergoing phacoemulsification with intraocular lens implantation and followed up for 1-5 years were included in this prospective cohort study. The severity of PCO was evaluated using EPCO2000 software system, with the area of central 3.0 mm (PCO-3 mm) and within the capsulorhexis (PCO-C) both being analyzed. Percentage of eyes after Nd:YAG capsulotomy, as well as clinically significant PCO (defined as eyes with visual-impairing PCO or after capsulotomy), were also included as outcome variables.

RESULTS

A total of 673 highly myopic eyes [axial length (AL) ≥ 26 mm] and 224 control eyes (AL < 26 mm) were analyzed. The mean follow-up time was 34.0 ± 9.0 months. PCO was more severe in highly myopic eyes compared with controls with regard to higher EPCO scores (P < 0.001 for both PCO-3 mm and PCO-C), higher capsulotomy rate (P = 0.001), higher clinically significant PCO rate (P < 0.001) and shorter PCO-free survival time (P < 0.001). Extreme myopia (AL ≥ 28 mm) would further aggravate PCO in terms of higher EPCO scores (PCO-3 mm: P = 0.017; PCO-C: P = 0.013) and higher clinically significant PCO rate (P = 0.024) compared with other myopic eyes. In highly myopic eyes, AL [odds ratio (OR) 1.124, P = 0.004] and follow-up duration (OR 1.082, P < 0.001) were independent risk factors for clinically significant PCO after cataract surgery.

CONCLUSION

Highly myopic eyes had more severe PCO in the long term. Longer AL and follow-up duration were associated with higher risk of PCO.

CLINICAL TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov (NCT03062085).

Development and Validation of a Prediction Model for Nd:YAG Laser Capsulotomy: A Retrospective Cohort Study of 9768 eyes

INTRODUCTION

Posterior capsular opacification (PCO) is the most common complication of cataract surgery. In this study, we develop a model to quantitatively predict the probability of Nd:YAG laser capsulotomy for vision-threatening PCO to improve the life quality of postoperative patients.

METHODS

A registry analysis of cataract procedures performed between the years 2010 and 2021. Following the screening of 16,802 patients (25,883 eyes), 9768 patients (eyes) were enrolled. The cohort was randomly divided into two groups: training (n = 6838) and validation (n = 2930). To identify relevant risk factors, univariate, multivariate, and Least Absolute Shrinkage and Selection Operator (LASSO) algorithm Cox regression analysis were employed, and a nomogram was created to demonstrate the prediction result.

RESULTS

At 5 years, the overall cumulative incidence of Nd:YAG laser capsulotomy was 12.0% (1169/9768). The following variables were included in the prediction model: sex [hazard ratio (HR) = 1.53, 95% CI 1.32-1.76], age (HR = 0.71, 95% CI 0.56-0.88), intraocular lens (IOL) material (HR = 2.65, 95% CI 2.17-3.24), high myopia (HR = 2.28, 95% CI 1.90-2.75), and fibrinogen (HR = 0.79, 95% CI 0.72-0.88). In the validation cohort, the area under the curve (AUC) of 1-, 3-, and 5-year predictions for Nd:YAG laser capsulotomy were 0.702, 0.691, and 0.688, respectively. For a subgroup of patients with high myopia, the protective effect of hydrophobic IOL disappeared (HR = 0.68, 95% CI 0.51-1.12, P = 0.127).

CONCLUSION

This model could predict the probability of Nd:YAG laser capsulotomy for vision-threatening PCO after cataract surgery by taking into account factors such as age, gender, IOL material, high myopia, and fibrinogen. Meanwhile, implantation of a hydrophobic IOL in individuals with high myopia did not demonstrate a protective impact against vision-threatening PCO.

The Technique of Phacoemulsification and Intraocular Lens Implantation in Subluxated Cataract Surgery

The purpose of this study was to investigate the effectiveness and practicability of phacoemulsification and intraocular lens implantation for subluxated cataracts. A retrospective review of subluxated cataract surgeries of 19 eyes performed in Kunhua Hospital Affiliated with Kunming University of Science and Technology between January 2017 and June 2021 was conducted. We choose to use the rotate-and-chop phacoemulsification techniques described when the crystal nucleus is rotated out of the capsular bag and simultaneously perform horizontal chops over the capsule. The viscoelastic agent was the important material that filled the capsule to support the capsular bag, and capsular hooks were used in 10 eyes necessarily. Anterior vitrectomy was undergone in 15 eyes. Single-piece intraocular lenses (IOL) were implanted in the capsular bag in 12 eyes including 8 capsular tension ring (CTR) implantation. Three-piece IOLs were fixed scleral layer in 7 eyes. Follow-up was 6 months to 2 years, and all eyes were successfully implanted with centered IOL. The best corrected visual acuity (BCVA) increased from 0.06 ± 0.04 to 0.62 ± 0.15. The cornea of all patients was clear, the intraocular lens was centered, the pupil was round, and the intraocular pressure was normal. Subluxated cataracts are a challenging surgery. The technique of phacoemulsification in subluxated cataract surgery is a key procedure to rotate and remove the lens from the capsule and at the same time horizontal chops and emulsification over the capsular bag to be performed. Viscoelastic agents and capsular hooks were important choices to support the capsule to reduce the incidence of complications related to the vitreous and retina and prevent the range enlarging of the zonular dialysis. A capsular tension ring was also an effective device to maintain capsular stability. Double-needle-guided scleral interlamellar fixation is an effective and practical method for IOL. Overall, the incision technique explored in this study and the surgical technique to support capsular stabilization provide a safe approach and satisfactory results in cataract surgery for subluxation.

Long-Term Clinically Significant Posterior Capsular Opacification Development Pattern in Eyes Implanted with an Aspheric Monofocal Intraocular Lens with a Square Optic Edge

Purpose

To analyse the posterior capsular opacification (PCO) development pattern in the long term in eyes implanted with a monofocal intraocular lens (IOL) with a square edge all around the optic.

Methods

Longitudinal retrospective study is data analyzed from a total of 7059 eyes from 4764 patients (mean age: 75.8 years) undergoing cataract surgery with implantation of an aspheric monofocal IOL (Bi-Flex HL 677AB/677P, Medicontur, Budapest, Hungary). These data were retrospectively collected using the electronic medical record of the hospitals involved. Nd : YAG capsulotomy rates were calculated per year during a follow-up of more than 10 years. The Kaplan–Meier analysis was used to establish the transparent capsule survival rate.

Results

The Nd : YAG capsulotomy rate increased from 1.1% at 1 year postoperatively to 17.2% at 5 years after surgery. No significant differences were found between eyes with and without capsulotomy in terms of age (p = 0.202), gender (p = 0.061), type of anaesthesia used (p = 0.128), and presence of conditions such as hard cataract (p = 0.111) or pseudoexfoliation (p = 0.137). IOL power was significantly lower in those eyes of patients requiring Nd : YAG capsulotomy during the follow-up (p < 0.001). Significantly more eyes implanted with the preloaded model of the IOL required capsulotomy (p < 0.001). Mean survival time and rate were 9.38 years and 85.9%, respectively.

Conclusions

Most eyes undergoing cataract with implantation of the Bi-Flex IOL do not develop a clinically significant PCO requiring Nd : YAG capsulotomy in the long term. IOL material and design may be the main factors accounting for this finding.

Anterior capsule coverage and rotational stability of an acrylic toric intraocular lens

PURPOSE

To investigate factors related to the rotational stability of an acrylic toric intraocular lens (IOL).

SETTING

Four ophthalmic surgical sites in Japan.

DESIGN

Prospective case series.

METHODS

The study included 120 eyes of 120 patients undergoing phacoemulsification and implantation of a toric IOL (AcrySof IQ, Alcon Laboratories, Inc.). At 1 hour postoperatively, the area of continuous curvilinear capsulorhexis (CCC) was measured, and the state of anterior capsule coverage on the IOL optic (total on or partial on) was recorded. The toric IOL axis orientation was assessed at the end of surgery and at 1 hour, 1 week, 1 month, and 6 months postoperatively. Multiple regression analysis was performed to explore any clinical factors relevant to IOL rotation from the end of surgery to 6 months postoperatively. The explanatory variables included age, anterior chamber depth preoperatively, axial length, type of corneal astigmatism (with-the-rule, against-the-rule, or oblique astigmatism), area of CCC, state of anterior capsule overlap on IOL optic (total coverage vs partial coverage), and surgical sites (surgeons).

RESULTS

The multiple regression analysis in 110 eyes of 110 patients indicated that anterior capsule overlap on the IOL optic was the only variable associated with IOL rotation at 6 months postoperatively (P = .0482). The mean absolute rotation at 6 months was 1.96 ± 1.81 degrees in the total on group and 3.79 ± 3.12 degrees in the partial on group (P = .0004).

CONCLUSIONS

Rotational stability of a single-piece, acrylic toric IOL was better in eyes with total anterior capsule coverage than that in those with partial anterior capsule coverage on the IOL optic.

[Influence of models of hydrophobic acrylic intraocular lenses on the development of posterior lens capsule opacifications (preliminary results)]

The search for optimal design and material of the intraocular lens (IOL) that would prevent posterior capsule opacification (PCO) is still a relevant problem.

PURPOSE

To compare the influence of three models of hydrophobic acrylic IOLs on the development of PCO within one year after phaco surgery.

MATERIAL AND METHODS

The study included 72 patients (91 eyes) who were followed up for 12 months after implantation of one of three models of posterior chamber hydrophobic acrylic IOLs: MIOL-2 (Reper-NN, Russia, 24 eyes, 1^st group), SA60AT and US60MP (Alcon, USA, 41 and 26 eyes, 2^nd and 3^rd groups, respectively). Posterior capsule images were taken and then processed with the EPCO 2000 (Evaluation of Posterior Capsular Opacification) software. The area of posterior capsule adjacent to the center of IOL's optic of 4.0 mm in diameter was estimated. PCO score was calculated as the weighted sum of opacification areas multiplied by the degree (from 0 to 4).

RESULTS

Within 1 year of the follow-up, mean visual acuity was at least 1.0 (20/20). Significant PCO progression was observed as early as 3 months after surgery. Despite that, opacification density in all three groups at every follow-up visit did not exceed grade 2; maximal PCO score (0.0315, median) was seen 12 month after surgery in the 1^st group. At the same time, differences in PCO score between the groups were not significant. Nd:YAG laser posterior capsulotomy was performed only in one patient from the 1^st group 12 month after surgery. Difference in the percentage of clear posterior capsules was significant only 12 month after surgery between the 1^st and 3^rd groups (p=0.024).

CONCLUSION

All three models of hydrophobic acrylic IOLs showed comparably high vision outcomess during 12 months of the follow-up with somewhat better PCO score and percentage of clear posterior capsules in eyes with US60MP.

Intraindividual comparison of capsule behavior of 2 hydrophobic acrylic intraocular lenses during a 5-year follow-up

PURPOSE

To evaluate and compare the 5-year postoperative anterior (ACO) and posterior capsule opacification (PCO), the occurrence of glistenings, and the level of anterior capsule retraction after implantation of 2 designs of 1-piece hydrophobic acrylic IOLs.

SETTING

Hospital St. John, Vienna, Austria.

DESIGN

Randomized controlled prospective case series.

METHODS

Patients had an Acrysof SA60AT IOL (Group A) implanted in 1 eye and a Tecnis ZCB00 IOL (Group B) implanted in the fellow eye. At 1, 3, and 5 years, the PCO level was evaluated with the Evaluation of Posterior Capsule Opacification software. The level of ACO and capsule retraction was graded subjectively. Glistenings were scored as present or not present.

RESULTS

Fifty eyes of 25 patients were evaluated after 5 years. No significant differences in PCO scores were found between the 2 groups at all follow-up visits (1 year: 0.06 ± 0.12 [SD] versus 0.07 ± 0.13, P = .35; 3 years: 0.23 ± 0.36 versus 0.22 ± 0.32, P = .66; 5 years: 0.36 ± 0.41 versus 0.36 ± 0.54, P = .98). A significant increase in PCO score was found between 3 and 5 years (P < .01). Anterior capsule opacification was present in Group A and Group B in 18.0% and 2.7% of eyes (P = .03), in 92.0% and 24.0% of eyes, and in 100% and 52% of eyes (P < .01) at 1, 3, and 5 years, respectively. Glistenings (5 years 100%) were observed in Group A.

CONCLUSION

Both IOLs had a comparable PCO rate 5 years after surgery, although more ACO and retraction as well as glistenings were observed in Group A.