Intraocular lens optic capture in pediatric cataract surgery

ErbBs in Lens Cell Fibrosis and Secondary Cataract

Purpose

TGFβ-induced epithelial-to-myofibroblast transition (EMyT) of lens cells has been linked to the most common vision-disrupting complication of cataract surgery-namely, posterior capsule opacification (PCO; secondary cataract). Although inhibitors of the ErbB family of receptor tyrosine kinases have been shown to block some PCO-associated processes in model systems, our knowledge of ErbB signaling in the lens is very limited. Here, we investigate the expression of ErbBs and their ligands in primary cultures of chick lens epithelial cells (dissociated cell-derived monolayer cultures [DCDMLs]) and how TGFβ affects ErbB function.

Methods

DCDMLs were analyzed by immunofluorescence microscopy and Western blotting under basal and profibrotic conditions.

Results

Small-molecule ErbB kinase blockers, including the human therapeutic lapatinib, selectively inhibit TGFβ-induced EMyT of DCDMLs. Lens cells constitutively express ErbB1 (EGFR), ErbB2, and ErbB4 protein on the plasma membrane and release into the medium ErbB-activating ligand. Culturing DCDMLs with TGFβ increases soluble bioactive ErbB ligand and markedly alters ErbBs, reducing total and cell surface ErbB2 and ErbB4 while increasing ErbB1 expression and homodimer formation. Similar, TGFβ-dependent changes in relative ErbB expression are induced when lens cells are exposed to the profibrotic substrate fibronectin. A single, 1-hour treatment with lapatinib inhibits EMyT in DCDMLs assessed 6 days later. Short-term exposure to lower doses of lapatinib is also capable of eliciting a durable response when combined with suboptimal levels of a mechanistically distinct multikinase inhibitor.

Conclusions

Our findings support ErbB1 as a therapeutic target for fibrotic PCO, which could be leveraged to pharmaceutically preserve the vision of millions of patients with cataracts.

Review of primary posterior capsulorhexis in cataract surgery

This article reviews the history and technique of primary posterior capsulorhexis with emphasis on anterior hyaloid membrane preservation and combined posterior optic capture of intraocular lenses into Berger's space for the purpose of lens stability and secondary cataract elimination among other potential advantages. Applications, variations, efficacy, and safety of the procedure are reviewed.

Drug-eluting intraocular lens with sustained bromfenac release for conquering posterior capsular opacification

Cataract is the leading cause of visual impairment, and posterior capsular opacification (PCO) is the most common long-term complication of modern cataract surgery, which can cause severe visual impairment after surgery. The proliferation, migration, and epithelial-mesenchymal transition (EMT) of residual lens epithelial cells (LECs) stimulated by growth factors and cytokines, are the key pathological mechanisms involved in the development of PCO. This study demonstrated that non-steroidal anti-inflammatory drug (NSAID), bromfenac, was capable of effectively inhibiting cell migration, overexpression of EMT markers, such as fibronectin (FN), matrix metalloproteinase 2 (MMP2), α-smooth muscle actin (α-SMA), and transcription factor Snail, and extracellular signal-regulated kinase (ERK)/glycogen synthase kinase-3β (GSK-3β) signaling induced by transforming growth factor-β2 (TGF-β2) in vitro. The inhibitory effect of bromfenac on TGF-β2-induced EMT was also verified on a primary lens epithelial cell model using human anterior capsules. Furthermore, based on ultrasonic spray technology, we developed a drug-eluting intraocular lens (IOL) using poly (lactic-co-glycolic acid) (PLGA) with sustained bromfenac release ability for the prevention of PCO development. In the rabbit models of cataract surgery, bromfenac-eluting IOL exhibited remarkable PCO prevention and inflammation suppression effects with excellent biocompatibility. In conclusion, bromfenac can inhibit TGF-β2-induced cell migration and the EMT of LECs via ERK/GSK-3β/Snail signaling. The present study offers a novel approach for preventing PCO through PLGA-based drug sustained-release IOLs.

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Bromfenac inhibited TGF-β2-induced migration and EMT of LECs through ERK/GSK-3β/Snail signaling.

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Drug-eluting IOLs with sustained bromfenac release were developed based on ultrasonic spray technology.

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Bromfenac-eluting IOLs exhibited remarkable PCO prevention and inflammation suppression effects in vivo.

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Bromfenac-eluting IOLs hold great potential for clinical application of PCO prevention.

Comparison of posterior optic capture of intraocular lens without vitrectomy vs endocapsular implantation with anterior vitrectomy in congenital cataract surgery: A randomized prospective study

Purpose:

To compare surgical outcome of two procedures in pediatric cataract surgery.

Methods:

Prospective randomised interventional study. Consecutive patients with bilateral congenital cataract who were operated during January 2016 to October 2016 at a tertiary care referral institute were included. One eye of all patients underwent Intraocular lens (IOL) implantation with optic capture through a primary posterior continuous curvilinear capsulorhexis (PPC) without vitrectomy while in the other eye endocapsular IOL implantation was performed along with PPC and anterior vitrectomy. Intraoperative challenges and postoperative complications were noted.

Results:

15/18 children who fulfilled the inclusion criteria were included for follow up analysis. Mean age at the time of surgery was 21 ± 14.7 months. At a mean follow up of 25.69 ± 1.06 months; all eyes in both groups maintained a clinically centred IOL with clear visual axis. One patient with endocapsular IOL implantation developed anterior capsular phimosis. The rate of fibrinous complications (IOL deposits and synechiae) were more in the eyes with IOL in the bag (6 eyes) vs eyes where posterior optic capture was done (1 eye); P = 0.039.

Conclusion:

Posterior optic capture is a safer alternative to conventional pediatric cataract surgery in terms of inflammatory sequelae and lens epithelial cell proliferation. However the two methods work equally well in preventing visual axis obscuration over a long follow-up.