Injected Versus Sponge-Applied Mitomycin C (MMC) During Modified Trabeculectomy in New Zealand White Rabbit Model

Long-term outcomes of Mitomycin-C augmented trabeculectomy using subconjunctival injections versus soaked sponges: a randomised controlled trial

PURPOSE

To compare the safety and efficacy of subconjunctival injection of Mitomycin C(MMC) with sponge-applied MMC during trabeculectomy.

METHODS

This prospective, randomised, interventional study was conducted on consecutive patients with uncontrolled glaucoma. 137 patients were randomised into an Injection group (Group 1, n = 66) and a sponge group (Group 2, n = 71). Trabeculectomy was performed in all patients who were followed up on days 1, 15, 30, 3 months, 6 months, 1 year, 2 years & 3 years postoperatively. Baseline & follow-up visits were compared to find out difference in the number of antiglaucoma medications (AGM), Intraocular pressure (IOP), and Best Corrected Visual Acuity (BCVA). In Group 1, the surgeon used MMC 0.2 mg/ml as subconjunctival injection and two separate semicircular surgical sponges soaked with MMC solution of 0.2 mg/mL were inserted subconjunctivally in Group 2.

RESULTS

Mean preop IOP was 34.21 ± 13.3 mmHg & 34.17 ± 10.6 mmHg in group 1 & 2 respectively, which reduced to 11.34 ± 3.7& 12.57 ± 4.7 mmHg(6 months),11.97 ± 4.2 & 13.60 ± 5.3 mmHg(1 year),12.42 ± 4.4 & 11.77 ± 2.8 mmHg (2 years) &11.25 ± 3.2 & 11.81 ± 3.2 mmHg at final visit(P < 0.001 in both groups)with no significant difference between the groups. The mean number of preoperative AGM was 2.32 ± 0.7 & 2.32 ± 0.8 in group1 & 2 respectively which reduced to 0.78 ± 0.9 (P < 0.001) & 1.13 ± 1.1(P = 0.930) at 3 years. Overall success rates were 75.3% in group 1 and 70.7% in group 2 at 3 years(p = 0.512). Postoperative complications and the final post-operative visual outcomes were similar between the groups.

CONCLUSION

Subconjunctival Injection of MMC is as safe and effective as sponge application with comparable surgical outcomes and complications in the long term.

LINC01605 knockdown induces apoptosis in human Tenon's capsule fibroblasts by inhibiting autophagy

Glaucoma is an irreversible disease that causes blindness. Formation of a hypertrophic scar (HS) is the main cause of failure of glaucoma surgery. The long non-coding RNA LINC01605 is closely associated with the formation of HS; however, the function of LINC01605 in the formation and development of HS remains unclear. For this study, firstly, human Tenon's capsule fibroblasts (HTFs) and corneal epithelial cells (control cells) were collected from patients (n=5) with POAG who underwent glaucoma filtration surgery at Fuyang People's Hospital. Immunofluorescence analysis was performed to detect the expression levels of vimentin (one of the main components of medium fiber and plays an important role in the cytoskeleton and motility), keratin (the main component of cytoskeletal proteins) and LC3 (an autophagy marker). In addition, reverse transcription-quantitative PCR analysis was performed to detect LINC01605 expression. Besides, the Cell Counting Kit-8 assay was performed to assess the viability of human Tenon's capsule fibroblasts (HTFs). Next, flow cytometry was performed to detect HTF apoptosis. Furthermore, western blot analysis was performed for Bax, Bcl-2, Pro-caspase-3, cleaved caspase-3, phosphorylated (p-)Smad2, Smad2, α-SMA, MMP9, ATG7, p62, beclin 1, p-AMPK and AMPK in HTFs to determine the mechanism by which LINC01605 regulates the formation and development of HS. Moreover, a Transwell assay was performed to detect the migratory ability of HTFs. The results demonstrated that LINC01605 was significantly upregulated in HS tissues compared with that in normal (control/healthy) tissues. In addition, vimentin was highly expressed in HTFs, whereas keratin was expressed at a low level. Also, in HTFs, LINC01605 knockdown inhibited cell viability by inducing apoptosis, decreasing Smad2 activation and inhibiting autophagy. Furthermore, LINC01605 knockdown significantly inhibited the migratory ability of HTFs. Transfection with LINC01605 small interference RNAs significantly downregulated the expression levels of p-Smad2, α-SMA and MMP9 in HTFs. Furthermore, LINC01605 knockdown notably inhibited the viability and migration, and induced the apoptosis of HTFs, the effects of which were reversed following treatment with TGF-β. Taken together, the results of the present study suggested that LINC01605 knockdown may inhibit the viability of HTFs by inducing the apoptotic pathway. These findings may provide novel directions for the treatment of HS.

Knockdown of FAM225B inhibits the progression of the hypertrophic scar following glaucoma surgery by inhibiting autophagy

The formation of a hypertrophic scar (HS) may lead to failure of glaucoma surgery. Long non-coding RNAs (lncRNAs) are involved in the formation of HSs. Moreover, family with sequence similarity 225 member B (FAM225B) is upregulated in HS. However, the role of the lncRNA FAM225B in HS remains unknown. Thus, the present study aimed to investigate the function of FAM225B in HS. Scar fibroblasts were isolated from patients who had undergone glaucoma surgery. Western blotting was used to detect the expressions of Bax, Bcl-2, cleaved caspase 3, p62, ATG7 and Beclin 1, and reverse transcription-quantitative PCR (RT-qPCR) were conducted to determine the level of FAM225B in scar fibroblasts. Microtubule associated protein 1 light chain 3 α staining was performed to examine autophagosomes in scar fibroblasts. Furthermore, cell proliferation was evaluated via 5-ethynyl-2′-deoxyuridine staining. Flow cytometry was conducted to determine cell apoptosis and the levels of reactive oxygen species (ROS) in scar fibroblasts. The cell migratory ability was assessed using a Transwell assay. The results demonstrated that FAM225B knockdown significantly attenuated scar fibroblast proliferation and induced apoptosis. Additionally, transfection of scar fibroblasts with FAM225B small interfering RNA (siRNA) significantly increased the ROS levels and significantly decreased the migration of scar fibroblasts. The FAM225B overexpression-induced increase of scar fibroblast proliferation and migration was significantly reversed by 3-methyladenine administration. The results suggested that knockdown of FAM225B significantly inhibited the proliferation of scar fibroblasts by inhibiting autophagy. Therefore, knockdown of FAM225B could inhibit scar fibroblast proliferation after glaucoma surgery by inhibiting autophagy. These findings may provide a novel perspective of developing treatment strategy for the patients with HSs after glaucoma surgery.