Elevated TGF-β2 level in aqueous humor of cataract patients with high myopia: Potential risk factor for capsule contraction syndrome

Purpose To evaluate the level of transforming growth factor-β2 (TGF-β2) in the aqueous humor of highly myopic cataract patients and its correlation with capsule contraction syndrome. Setting Eye and ENT Hospital of Fudan University, Shanghai, China. Design Prospective comparative case series. Methods The highly myopic cataract patients were divided into the following 2 groups according to the Lens Opacity Classification System III: nuclear color (NC) 2 to 3 and NC 5 to 6. Aqueous humor TGF-β2 concentrations were assayed in the highly myopic cataract and age-related cataract groups. The TGF-β2, TGF-βRII (the type II receptor for TGF-β2), and α-smooth muscle actin (α-SMA) expressions in lens epithelial cells (LECs) were detected by real-time polymerase chain reaction and immunofluorescent staining. Results The study comprised 40 highly myopic cataract patients (40 eyes) and 20 patients (20 eyes) with age-related cataract as the control group. Compared with the control group, the highly myopic cataract group had significantly higher TGF-β2 concentration in the aqueous humor and increased TGF-βRII expression in LECs, especially in NC 5 to 6 cases. Expression of α-SMA was barely detectable in both groups. Conclusion In highly myopic cataract patients, especially those with dark nuclei, elevated aqueous humor TGF-β2 levels and the upregulated TGF-βRII expression in LECs might contribute to the pathogenesis of capsule contraction syndrome through transdifferentiation of LECs into myofibroblasts. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.