Shogo Arimura

The Effect of Photocoagulation in Ischemic Areas to Prevent Recurrence of Diabetic Macular Edema After Intravitreal Bevacizumab Injection

PURPOSE This study aimed to investigate whether targeted retinal photocoagulation (TRP) for nonperfused areas (NPAs) could have a preventive effect on the recurrence of diabetic macular edema (DME) after intravitreal injection of bevacizumab (IVB). METHODS Eyes in the IVB group received 1.25 mg IVB, and eyes in the IVB+TRP group received 1.25 mg IVB combined with TRP of NPAs. Two weeks before IVB administration, grid/focal photocoagulation (PC) had been performed in both groups. After IVB treatment, the best corrected visual acuity (BCVA) and central retinal thickness (CRT), determined by optical coherence tomography, were measured every month for 6 months. RESULTS Fifty-two patients with DME were enrolled and randomized to an IVB group (n = 26) and an IVB+TRP group (n = 26). After IVB, the CRT decreased temporally, and the CRT significantly increased at 2 months and thereafter in the IVB group but did not increase significantly in the IVB+TRP group. Maximum increase in CRT after IVB was significantly correlated with the width of NPAs in the IVB group (P = 0.0368), but not in the IVB+TRP group. Best corrected visual acuity in the IVB+TRP group was significantly better than that in the IVB group 5 and 6 months after treatment (P < 0.05). CONCLUSIONS Targeted retinal photocoagulation for NPAs was effective to maintain the reduced CRT after grid/focal PC and IVB for patients with DME. These results suggest that retinal ischemia is associated with the pathogenesis of recurrence of DME after IVB. ( www.umin.ac.jp/ctr number, UMIN000007566.).

Comparison of the Inverted Internal Limiting Membrane Flap Technique and the Internal Limiting Membrane Peeling for Macular Hole with Retinal Detachment

Purpose To evaluate the efficacy of the inverted internal limiting membrane (ILM) flap technique in vitrectomy for macular hole (MH) with retinal detachment (RD) compared with vitrectomy using ILM peeling. Methods A retrospective case series study was performed. Twenty-two eyes of 22 patients who underwent vitrectomy for MH with RD and followed-up more than 12 months after the surgery were included in this study. We retrospectively reviewed the medical records of patients who underwent vitrectomy with inverted ILM flap technique or vitrectomy with ILM peeling. Ten patients who had been treated vitrectomy with inverted ILM flap technique, and 12 patients who had been treated vitrectomy with ILM peeling were analyzed. We evaluated changes in best-corrected visual acuity (BCVA) before and after surgery, closing rates of MH, and retinal reattachment rates and compared between both groups. Results MH was closed and RD was reattached postoperatively in 9 eyes (90%) in the inverted ILM flap group. In the ILM peeling group, the MH was closed in 4 eyes (33.3%) and the retinas were reattached in 6 eyes (50%) after surgery. Significant improvement in BCVA after surgery (P = 0.0017) was only found in the inverted ILM flap group. Conclusions Higher rates of closed MH and retinal reattachment, and small but significant improvement in BCVA were found in the inverted ILM flap group. Based on our data, the inverted ILM flap technique may be useful in vitrectomy for MH with RD.

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.

Comparative study of combined bevacizumab/targeted photocoagulation vs bevacizumab alone for macular oedema in ischaemic branch retinal vein occlusions

To investigate whether targeted retinal photocoagulation (TRP) of peripheral non‐perfused areas (NPAs) could prevent the recurrence of macular oedema (ME) due to branch retinal vein occlusion (BRVO) after intravitreal bevacizumab injection (IVB).

Anterior capsule contraction and flare intensity in the early stages after cataract surgery in eyes with diabetic retinopathy

Purpose To evaluate the changes and relationship in the area of the anterior capsule opening (ACO) and anterior inflammation during the early stages after cataract surgery in diabetic patients with or without diabetic retinopathy (DR). Setting Department of Ophthalmology, University of Fukui, Fukui, Japan. Design Case‐control study. Methods This study comprised diabetic patients without DR (non‐DR group), diabetic patients with nonproliferative DR (DR group), and patients without diabetes mellitus (DM) (non‐DM group) who had cataract surgery. The ACO area and aqueous flare intensity were measured using the EAS‐1000 device and a laser flare–cell meter, respectively, 1 day, 1 week, and 1 and 3 months after surgery. Results The percentage of anterior capsule contraction (ACC) was significantly higher in the DR group than in the non‐DR and non‐DM groups 1 week and 1 and 3 months postoperatively (P<.01, Turkey‐Kramer test). The aqueous flare intensity was significantly greater in the DR group than in the non‐DR and non‐DM groups 1 day, 1 week, and 1 and 3 months postoperatively (P<.01). Ordinary least‐squares regression analysis showed a significant positive correlation between aqueous flare intensity at 1 week and ACC 3 months after surgery in the non‐DR group (P=.0178, R2 = 0.173) and the DR group (P=.0018, R2 = 0.308). Conclusion Greater anterior flare levels 1 week after cataract surgery contributed to the extensive postoperative contraction of the ACO in diabetic patients, particularly those with DR. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Altered Transport Velocity of Axonal Mitochondria in Retinal Ganglion Cells After Laser-Induced Axonal Injury In Vitro.

PURPOSE Axonal damage precedes retinal ganglion cell (RGC) apoptosis in glaucomatous optic neuropathy. Because mitochondria in RGC axons are damaged before cell death, we examined axonal mitochondrial transport dynamics after axonal injury. METHODS Mitochondria in rat-cultivated RGCs were stained with rhodamine 123. After axonal injury induced using a laser microdissection system, axonal transport was evaluated by time-lapse imaging. The RGC apoptosis was detected using ethidium homodimer-1 on day 3 after axonal injury. RESULTS The rate of stationary mitochondria in RGC axons significantly increased from 37.6% before axonal injury to 70.6% at 5 minutes (P < 0.001) and 63.6% at 18 hours (P < 0.001) after axonal injury. The mean axonal mitochondrial transport velocity in RGCs transiently deteriorated from 0.48 ± 0.01 μm/s before axonal injury to 0.37 ± 0.02 μm/s at 5 minutes after axonal injury (P < 0.001). However, 23.5% of RGCs showed recovered axonal transport velocity at 18 hours after injury. On day 3 after axonal injury, RGCs with the recovery of axonal transport did not undergo apoptosis, whereas 69.2% of RGCs without the recovery of axonal transport underwent apoptosis (P = 0.029). CONCLUSIONS Axonal injury disrupts mitochondrial transport in RGC axons. Irreversible decreased axonal mitochondrial transport velocity may be useful to predict RGC apoptosis after axonal injury.

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.

Changes in Matrix Metalloproteinases in Diabetes Patients' Tears After Vitrectomy and the Relationship With Corneal Epithelial Disorder.

PURPOSE Previous studies indicate involvement of matrix metalloproteinases (MMPs) in the pathogenesis of diabetic keratopathy. To evaluate MMP levels in the tears of patients with diabetes, we investigated changes in MMP levels during perioperative periods and clarify the relationship with corneal epithelial disorders following vitrectomy. METHODS Matrix metalloproteinase levels in tears were measured by multiplex bead array in patients with or without diabetes who were scheduled for vitrectomy. Twenty-two patients with diabetes and proliferative diabetic retinopathy, and 20 patients with epiretinal membrane or macular hole (control group), were recruited. Changes in MMP levels during perioperative periods and the relationship with corneal epithelial disorders after vitrectomy were analyzed. RESULTS The levels of MMP-2, -9, and -10 at 1 day after surgery in the diabetic group were significantly higher than in the control group. At 1 week after surgery, MMP-10 levels in the diabetic group were significantly higher than in the control group. After vitrectomy, corneal epithelial disorders occurred in six patients in the diabetic group but not in the control group. In the diabetic group, MMP-10 levels in tears of patients with corneal epithelial disorders were significantly higher than those in patients without corneal epithelial disorders. CONCLUSIONS The MMP concentration in tears of patients with diabetes was higher than in nondiabetic patients after vitrectomy. High MMP-10 levels were observed in patients with diabetes and corneal epithelial disorders after vitrectomy. Aberrant levels of MMP-10 may cause corneal epithelial disorder after vitrectomy.

Relationship between lenticular power and refractive error in children with hyperopia

Objectives To evaluate the contribution of axial length, and lenticular and corneal power to the spherical equivalent refractive error in children with hyperopia between 3 and 13 years of age, using noncontact optical biometry. Methods There were 62 children between 3 and 13 years of age with hyperopia (+2 diopters [D] or more) who underwent automated refraction measurement with cycloplegia, to measure spherical equivalent refractive error and corneal power. Axial length was measured using an optic biometer that does not require contact with the cornea. The refractive power of the lens was calculated using the Sanders-Retzlaff-Kraff formula. Single regression analysis was used to evaluate the correlation among the optical parameters. Results There was a significant positive correlation between age and axial length (P = 0.0014); however, the degree of hyperopia did not decrease with aging (P = 0.59). There was a significant negative correlation between age and the refractive power of the lens (P = 0.0001) but not that of the cornea (P = 0.43). A significant negative correlation was observed between the degree of hyperopia and lenticular power (P < 0.0001). Conclusion Although this study is small scale and cross sectional, the analysis, using noncontact biometry, showed that lenticular power was negatively correlated with refractive error and age, indicating that lower lens power may contribute to the degree of hyperopia.