Kentaro Iwasaki

The effect of triamcinolone acetonide or bevacizumab on the levels of proinflammatory cytokines after retinal laser photocoagulation in pigmented rabbits.

Although laser photocoagulation is a gold standard for the treatment of retinal ischemic diseases, thermal burn induces the inflammation and the progression of macular edema. To prevent this complication, combination therapy using anti-vascular endothelial growth factor (VEGF) drugs or steroids is clinically utilized, however the mechanisms are still unclear. In this study, we aimed to evaluate the changes in inflammatory and angiogenic cytokine levels in aqueous humor and vitreous body after intravitreal injection of bevacizumab (IVB) or triamcinolone (IVTA), as well as sub-Tenon injection of triamcinolone (STTA) after retinal laser photocoagulation in rabbits. Pigmented rabbits were treated with retinal laser photocoagulation and divided into 4 groups, namely Control (no additional treatment), IVB, IVTA or STTA accordingly. Samples of vitreous and aqueous humor were collected on post-treatment days 0, 1, 7 and 14. The levels of intraocular VEGF, interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1) and monocyte chemotactic protein-1 (MCP-1) were measured using an immunoassay. The levels of VEGF, IL-6, ICAM-1 and MCP-1 were significantly elevated 1 day after laser treatment. IVTA and STTA significantly reduced the increase in the levels of VEGF, IL-6, ICAM-1 and MCP-1, while IVB reduced that of VEGF only in aqueous humor and vitreous body. The protein amount in the aqueous humor transiently increased 1 day after laser, and was significantly prevented by IVTA or STTA but not IVB. Data showed that bevacizumab only reduced intraocular VEGF after laser, while triamcinolone suppressed both the expression of VEGF and proinflammatory cytokines. We propose that these cytokine profiles may play an important role in the pathogenesis of inflammation after photocoagulation and the underlying mechanism of treatment with anti-VEGF drug and steroids.

Panretinal Photocoagulation Using Short-Pulse Laser Induces Less Inflammation and Macular Thickening in Patients with Diabetic Retinopathy

We compared the effect of panretinal photocoagulation (PRP) using short-pulse laser (SPL) and conventional laser, regardless of the number of spots, in terms of their effect on the progression of diabetic macular edema (DME) and anterior flare intensity (AFI) in patients with high-risk nonproliferative diabetic retinopathy (non-PDR). Forty-two eyes of 42 patients were subjected to PRP using the conventional argon laser (Conv group) or SPL (SPL group). CRT and AFI levels in the SPL group were significantly lower than those in the Conv group (CRT at 4, 6, and 10 weeks; AFI at 6, 10, and 18 weeks). Eyes of rabbits were photocoagulated using conventional laser with 500 spots (Conv 500s), SPL with 500 spots (SPL 500s), or 1000 spots (SPL 1000s). Vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), and monocyte chemotactic protein-1 (MCP-1) levels in vitreous humor were measured using an immunoassay. Compared to conventional laser, VEGF, IL-6, and MCP-1 levels were significantly lower in the SPL 1000s and SPL 500s groups. In patients with high-risk non-PDR, SPL has a greater preventive effect on the progression of DME and AFI and produces less inflammatory cytokines than conventional lasers.

Comparison of subconjunctival scarring after microincision vitrectomy surgery using 20-, 23-, 25- and 27-gauge systems in rabbits

To compare subconjunctival scarring after vitrectomy in rabbit eyes using different gauge systems by analysing anterior segment optical coherence tomography (AS‐OCT) images and histological sections.

Randomized Clinical Trial for Early Postoperative Complications of Ex-PRESS Implantation versus Trabeculectomy: Complications Postoperatively of Ex-PRESS versus Trabeculectomy Study (CPETS).

We compared early postoperative complications between trabeculectomy and Ex-PRESS implantation. Enrolled patients with 39 primary open-angle or 25 exfoliative glaucoma were randomly assigned to receive trabeculectomy (trabeculectomy group) or Ex-PRESS implantation (Ex-PRESS group). Primary outcomes were early postoperative complications, including postoperative anterior chamber inflammation, frequencies of hyphema, flat anterior chamber, choroidal detachment, hypotonic maculopathy, and the change of visual acuity. The postoperative flare values in trabeculectomy group were higher than those in the Ex-PRESS group (overall, P = 0.004; and 10 days, P = 0.02). Hyphema occurred significantly more frequently in the trabeculectomy group (P = 0.0025). There were no significant differences of the other primary outcomes between the two groups. Additionally, duration of anterior chamber opening was significantly shorter in the Ex-PRESS group (P = 0.0002) and the eyes that had iris contact with Ex-PRESS tube had significantly shallower anterior chambers than did the eyes without the iris contact (P = 0.013). The Ex-PRESS implantation prevented early postoperative inflammation and hyphema in the anterior chamber and shortened the duration of anterior chamber opening. Iris contact with the Ex-PRESS tube occurred more frequently in eyes with open-angle glaucoma and shallow anterior chambers.

Comparing trabeculectomy outcomes between first and second operated eyes: A multicenter study

Objective To compare surgical outcomes between the first and second operated eyes in patients who underwent trabeculectomy in both eyes. Methods This retrospective clinical cohort study at five clinical centers in Japan included 84 patients with open-angle glaucoma who underwent primary trabeculectomy in both eyes. The primary outcome was surgical success or failure, with failure being defined according to three criteria: <20% reduction of the preoperative intraocular pressure (IOP), or Criterion A, IOP >21 mmHg; Criterion B, IOP >18 mmHg; or Criterion C, IOP >15 mmHg. Cases of reoperation, a loss of light perception vision, or hypotony were also considered as “failures”. Results There were no significant differences in success rate for any of the three criteria between the first and second operated eyes. For patients whose first trabeculectomy was successful, when the second trabeculectomy was performed ≥2 months after the first, the survival curves for all three criteria for the second trabeculectomy were significantly worse than those for patients waiting a shorter interval between trabeculectomies (Criterion A, 52.0% vs 83.6%, P = 0.0031; Criterion B, 51.5% vs 80.4%, P = 0.026; Criterion C, 51.1% vs 80.4%, P = 0.048). In multivariable analyses, a longer interval between trabeculectomies was a significant prognostic factor for surgical failure (Criterion A, P = 0.0055; Criterion B, P = 0.0023; Criterion C, P = 0.027). However, no dependency on the interval between trabeculectomies was found among patients whose first trabeculectomy failed. Conclusions If the first trabeculectomy is successful, a long interval before the second trabeculectomy increases the risk of surgical failure in the second eye. This result has clinical implications for developing surgical strategies for patients with bilateral glaucoma.

Randomised Clinical Trial for Postoperative Complications after Ex-PRESS Implantation versus Trabeculectomy with 2-Year Follow-Up

We compared complications between Ex-PRESS implantation and trabeculectomy for 2 years after surgery. Sixty-four open-angle glaucoma eyes were randomly assigned to treatment with trabeculectomy (n = 32) or Ex-PRESS implantation (n = 32). The primary outcomes were postoperative complications, including reduction of the endothelial cell density (ECD) of the cornea, cataract progression and the frequency of other late postoperative complications. The Ex-PRESS group had significantly greater reduction of postoperative corneal ECD than the trabeculectomy group did at 2 years after surgery (P = 0.026). Among the corneal areas measured using specular microscopy, the superior area, where the Ex-PRESS tube was inserted, had significantly more severe corneal ECD reduction than the inferior area after 2 years (−17.6% in superior area and −11.7% in inferior area, P = 0.04). More cataract progression occurred in the trabeculectomy group than in the Ex-PRESS group (P = 0.04). Twelve eyes (37.5%) in the trabeculectomy group and 4 eyes (12.5%) in the Ex-PRESS group underwent cataract surgery (P = 0.019). The total number of other postoperative complications between 3 months and 2 years was significantly higher in the trabeculectomy group than in the Ex-PRESS group (P = 0.02). Although Ex-PRESS implantation might be associated with an increased rate of corneal endothelial cell loss compared with trabeculectomy, it is beneficial for preventing cataract progression after filtering surgery.

Prospective cohort study of corneal endothelial cell loss after Baerveldt glaucoma implantation

Purpose To evaluate corneal endothelial cell loss after Baerveldt glaucoma implantation. Methods We prospectively evaluated changes in endothelial cell density (ECD) in the cornea of 59 patients (59 eyes) who underwent Baerveldt glaucoma implantation. Tubes were inserted into the anterior chamber in 45 eyes and pars plana in 14 eyes. The primary outcome measure was the change in corneal ECD after Baerveldt glaucoma implantation. Secondary outcome measures included relationships between corneal ECD and optical coherence tomography images of tube parameters (tube–cornea distance and tube–cornea angle) and prognostic factors for corneal ECD loss. Results Corneal ECD decreased significantly by 9.2% at 12 months after surgery (P = 0.001). In the anterior chamber Baerveldt glaucoma implantation group, corneal ECD at the tube insertion quadrant decreased significantly by 9.6% at 3 months (P = <0.001), 10.7% at 6 months (P = <0.001), and 13.1% at 12 months (P = <0.001). Corneal ECD at the center decreased significantly at 6 months after surgery (7.2% loss; P = 0.012) and at 12 months after surgery (12.1% loss; P = 0.001). Corneal ECD at the contralateral quadrant decreased significantly at 12 months after surgery only (10.3% loss; P = 0.004). In the pars plana Baerveldt glaucoma implantation group, no significant loss of corneal ECD was found in any corneal areas at any post-surgery follow-up visits. Tube-cornea angle was negatively correlated with the rate of corneal ECD loss at the tube insertion quadrant; r = −0.55 (P = 0.0013). In multivariable analyses, exfoliation glaucoma and narrower tube–cornea angle were significant prognostic factors for severe corneal ECD loss (P = 0.0068 and P = 0.046, respectively). Conclusions Anterior chamber Baerveldt glaucoma implantation causes corneal endothelial cell loss. Corneal endothelial cell loss starts at the tube insertion quadrant. Exfoliation glaucoma and narrower tube-corneal angle are associated with severe loss of corneal endothelial cells.

Evaluation of Bleb Fluid After Baerveldt Glaucoma Implantation Using Magnetic Resonance Imaging

We evaluated bleb fluid images taken after Baerveldt glaucoma implantation. T2-weighted images of bleb fluid were scanned with 3 Tesla magnetic resonance imaging in 52 patients who had undergone tube-shunt surgery using the 350-mm2 endplate Baerveldt glaucoma implant; three-dimensional images were constructed from these images. Bleb fluid images were classified into either a layer of bleb fluid on either side of the endplate (double bleb layer group; n = 24) or one layer outside the endplate (single bleb layer group; n = 28). Despite there being no correlation between the bleb volume and the postoperative IOP (r = −0.080; P = 0.57), the double bleb layer group had significantly lower postoperative IOPs than the single bleb layer group (12.3 ± 3.8 mmHg vs. 14.7 ± 4.1 mmHg, respectively; P = 0.033). The single bleb layer was significantly related to higher numbers of prior intraocular surgeries (relative risk = 2.85; P = 0.0014). Formation of a layer of bleb fluid on either side of the endplate may have resulted in the lower postoperative IOPs after Baerveldt glaucoma implantation. Repeated intraocular surgery adversely affects formation of the double bleb layer.