Comparison of posterior capsule opacification at 360-degree square edge hydrophilic and sharp edge hydrophobic acrylic intraocular lens in diabetic patients

Factors Affecting Posterior Capsule Opacification in the Development of Intraocular Lens Materials

Posterior capsule opacification (PCO) is the most common complication arising from the corrective surgery used to treat cataract patients. PCO arises when lens epithelial cells (LEC) residing in the capsular bag post-surgery undergo hyper-proliferation and transdifferentiation into myofibroblasts, migrating from the posterior capsule over the visual axis of the newly implanted intraocular lens (IOL). The developmental pathways underlying PCO are yet to be fully understood and the current literature is contradictory regarding the impact of the recognised risk factors of PCO. The aim of this review is firstly to collate the known biochemical pathways that lead to PCO development, providing an up-to-date chronological overview from surgery to established PCO formation. Secondly, the risk factors of PCO are evaluated, focussing on the impact of IOLs’ properties. Finally, the latest experimental model designs used in PCO research are discussed to demonstrate the ongoing development of clinical PCO models, the efficacy of newly developed IOL technology, and potential therapeutic interventions. This review will contribute to current PCO literature by presenting an updated overview of the known developmental pathways of PCO, an evaluation of the impact of the risk factors underlying its development, and the latest experimental models used to investigate PCO. Furthermore, the review should provide developmental routes for research into the investigation of potential therapeutic interventions and improvements in IOL design in the aid of preventing PCO for new and existing patients.

Novel Technique of Pneumatic Posterior Capsulorhexis for Treatment and Prevention of Posterior Capsular Opacification

PURPOSE

To evaluate a new technique of posterior capsulorhexis using air support to treat primary posterior capsular opacification (PCO) during cataract extraction surgery or to prevent postoperative PCO.

SETTING

(1) Ophthalmology department, Faculty of Medicine, Minia University, 61519, El-Minia, Egypt. (2) Security Forces Hospital, Ophthalmology Department, Riyadh, Kingdom of Saudi Arabia.

DESIGN

Prospective, randomized, consecutive case comparative non controlled study.

METHODS

One hundred eyes of 100 patients with a mean age of 63.3 years with dense cataract were enrolled in the study. Fifty of them (group (1)) were with primary PCO (discovered during the operations) and fifty (group (2)) with clear posterior capsule. All of the patients underwent phacoemulsification and posterior capsulorhexis using the air to support the posterior capsule. Then, IOL implantations were done between the anterior and posterior capsular rims. Postoperatively, each patient was evaluated for the following: visual acuity (UCVA and BCVA), manifest refractive spherical equivalent (MRSE), intraocular pressure, intraocular lens (IOL) stability, visual axis opacification, and posterior segment complications as retinal breaks, retinal detachment, or cystoid macular edema (CME).

RESULTS

There were no significant differences in UCVA, BCVA, and MRSE. All cases had a clear visual axis, with stable IOL and normal IOP during the follow-up period without posterior segment complications. The VA improved significantly throughout the follow-up periods in both groups without significant clinical difference.

CONCLUSION

Pneumatic posterior capsulorhexis is a new effective technique for the treatment of primary PCO in dense cataract and for prevention of postoperative PCO with the good visual outcomes and minimal complications. This trial is registered with NCT04007965.

A comparison of posterior capsular opacification after implantation of three different hydrophobic square edge intraocular lenses

Purpose

To compare the posterior capsular opacification (PCO) after implantation of three types of hydrophobic square edge intraocular lenses (IOLs).

Methods

A single-center, hospital-based, cross-sectional, observational study was conducted wherein patients with senile cataract who had undergone phacoemulsification by a single surgeon, with the implantation of three different types of square edge, hydrophobic IOLs [Group 1: enVista, Bausch and Lomb; Group 2: Tecnis 1 ZCBOO, AMO and Group 3: Acrysof IQ SN60WF, Alcon], and followed up for 12 months were included. The PCO was graded clinically and scored using the EPCO 2000 software.

Results

90 eyes of 90 patients were included. There was no significant difference in the PCO with respect to age, gender, or associated presence of systemic disease. The median PCO score was 0.035, 0.045 and 0.085 in groups 1, 2 and 3, respectively. The PCO grade and score differences between the groups were statistically significant with P < 0.001.

Conclusion

The hydrophobic nature and posterior square edge design in the IOLs probably contributed to the minimal visually-significant PCO in all the groups, in our study. However, PCO scores were lesser in the square edge IOLs having a continuous 360 degrees posterior enhanced barrier, than those without this feature.

Retrospective Analyses of Potential Risk Factors for Posterior Capsule Opacification after Cataract Surgery

PURPOSE

To evaluate the potential risk factors of posterior capsule opacification (PCO) after cataract surgery.

METHODS

Data on PCO patients diagnosed from September 2015 to May 2017 were obtained from the Department of Ophthalmology at Qingdao Municipal Hospital, Qingdao, China. The factors associated with PCO were assessed using Pearson's χ2 test for univariate analyses and logistic regression for multivariate analyses.

RESULTS

Eyes (652) from 550 patients were enrolled in this study. All patients were diagnosed with PCO/non-PCO and had <3 years of follow-up after surgery. The numbers of PCO and non-PCO were 108 eyes and 544 eyes, respectively. Statistically significant associations with PCO were found for age at the time of surgery (χ2 = 78.504; p < 0.001), diabetes (χ2 = 4.829; p=0.028), immune diseases (χ2 = 4.234; p=0.004), high myopia (χ2 = 5.753; p=0.016), lens nucleus hardness (χ2 = 11.046; p=0.026), surgery type (χ2 = 11.354; p=0.001), a history of vitrectomy (χ2 = 4.212; p=0.004), ocular inflammation (χ2 = 6.01; p=0.009), and the intraocular lens (IOL) type (χ2 = 8.696; p=0.003). Multivariable data analyses using logistic regression analyses of the variables showed that age at the time of surgery <60 years, diabetes, lens nucleus hardness of III-V, extracapsular cataract extraction (ECCE), postvitrectomy, and hydrophilic IOLs were significant independent risk factors associated with PCO.

CONCLUSIONS

Age <60 years, diabetes, lens nucleus hardness of III-V, ECCE, postvitrectomy, and a hydrophilic IOL were significantly associated with the formation of PCO. Estimation of the incidence of and risk factors for PCO should help in patients counseling and in the design of treatment protocols to reduce or prevent its development.

Postoperative posterior capsular striae and the posterior capsular opacification in patients implanted with two types of intraocular lens material

AIM

To evaluate the incidence of postoperative posterior capsular striae (PCS) and its influence on posterior capsular opacification (PCO) in patients implanted with two types of lens material.

SETTING

Tertiary eye care center in central rural India.

STUDY DESIGN

A prospective, observational, nonrandomized study.

MATERIALS AND METHODS

The study included 1247 patients having age-related cataract scheduled for removal by phacoemulsification technique and implantation of hydrophilic or hydrophobic intraocular lens (IOL). Demographic profile, nuclear grading, axial length, and IOL power were noted. Details of PCS were noted on the 1st postoperative day in patients with clear cornea. Postoperative follow-up was ensured to study the status of PCS and development of PCO.

RESULTS

The overall incidence of PCS was 19.8% (247 out of 1247 eyes). Out of 1247 patients, 641 patients (51.4%) had hydrophilic IOL implantation and 201 eyes had PCS (31.4%) and 606 patients (48.6%) had hydrophobic IOL implantation and 46 eyes had PCS (7.6%), P = 0.04. Three and more striae were seen in 119 eyes (119/641, 18.6%) in hydrophilic group and 4 eyes (4/606, 0.66%) in hydrophobic group. Sixty-two eyes (62/201, 30.9%) in hydrophilic group with multiple PCS were reported with persistent striae after 6 months of surgery. Two eyes in hydrophobic group had persistent striae even after 3 years of follow-up. Evaluation of PCO score of the hydrophilic group was 0.6 whereas of the hydrophobic group was 0.1 (P = 0.04). Ten patients of the hydrophilic group only required neodymium-doped yttrium aluminum garnet (ND: YAG) laser capsulotomy.

CONCLUSION

The incidence of PCS was higher in hydrophilic than hydrophobic IOLs. Multiple PCS persisting in patients beyond 6 months after operation should be followed up for early development of PCO, particularly in patients implanted with hydrophilic IOL.