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

Biodegradable Poly(d,l-lactide-co-ε-caprolactone) Electrospun Scaffolds Outperform Antifibrotic-Loaded Meshes in an in Vivo Tissue Regeneration Model

Wound healing is a complex and dynamic process of replacing missing cellular structures and tissue layers. Clinical practice includes the application of a sterile bandage to promote healing and to restrain infection, like the commercial nonbiodegradable meshes. However, while inert, nontoxic, and nonimmunogenic, they can cause calcification, fibrosis, and inflammation, potentially hindering the healing process in the long term. To address this challenge and enhance wound healing, we developed a totally biodegradable electrospun poly(d,l-lactide-co-ε-caprolactone) (PDLLCL) drug delivery system that incorporates two already FDA-approved antifibrotics, pirfenidone (PIRF) and triamcinolone acetonide (TA). The PDLLCL meshes, fabricated via electrospinning, exhibited homogeneity and complete degradation after 120 days, consistent with the wound healing process. In vitro, functional analysis on RAW 264.7 macrophages revealed no cytotoxicity and an immunomodulatory effect of PIRF and TA compared with the positive control (lipopolysaccharides, LPS) and the PDLLCL meshes alone. Lastly, subcutaneous in vivo assessment on a rabbit model, following the ISO 10993-6 standard, showed that our tailored made PDLLCL meshes were able to lower both irritation and fibrosis indexes from 2 weeks to 4 weeks of implantation, highlighting the beneficial effect of biodegradable polymers. However, we saw no significant positive effect on the incorporation of antifibrotics in vivo for irritation and fibrosis indexes. This underscores the potential of PDLLCL meshes as a possible alternative for wound healing, reducing the use of intermittent antifibrotic agents during the healing process.

Long-term longitudinal retinal changes after conventional and pattern scan laser panretinal photocoagulation in diabetic retinopathy

PURPOSE

Comparison the effect of conventional and pattern scan laser (PASCAL) panretinal photocoagulation (PRP) on macula and optic disk in diabetic retinopathy (DR).

METHODS

This retrospective study included 57 patients. In the conventional laser group, PRP was completed using the LightMed LightLas 532 laser device in accordance with the ETDRS protocol. In the pattern laser group, it was completed in a single session using PASCAL device with 20 ms pulse duration and multispot pattern. Central macular thickness (CMT) and retinal nerve fiber layer (RNFL) thickness were evaluated before laser treatment and at 1, 6 and 12 months after treatment.

RESULTS

There were 30 eyes in the conventional laser group and 27 eyes in the PASCAL group. There was no significant difference between the groups in terms of age (p = 0.560), sex (p = 0.866), duration (p = 0.498) and stage (p = 0.503) of diabetes, visual acuity (p = 0.104) and intraocular pressure (p = 0.963).In both groups, CMT increased significantly (p ˂0.001), while RNFL thickness decreased significantly (p ˂0.001) at 12 months. While CMT and mean RNFL thickness increased in the first month in both groups, it decreased progressively until the 12th month.

CONCLUSION

Conventional and pattern laser systems used in the treatment of DR................ cause an increase in CMT and thinning of RNFL thickness in the long term. This change is more in the conventional laser group compared to the pattern laser.

Nuclear Receptor Atlases of Choroidal Tissues Reveal Candidate Receptors Associated with Age-Related Macular Degeneration

The choroid is a vulnerable tissue site in the eye, impacted in several blinding diseases including age related macular degeneration (AMD), which is the leading cause of central vision loss in the aging population. Choroidal thinning and choriocapillary dropout are features of the early form of AMD, and endothelial dysfunction and vascular changes are primary characteristics of the neovascular clinical sub-type of AMD. Given the importance, the choroidal endothelium and outer vasculature play in supporting visual function, a better understanding of baseline choroidal signaling pathways engaged in tissue and cellular homeostasis is needed. Nuclear receptors are a large family of transcription factors responsible for maintaining various cellular processes during development, aging and disease. Herein we developed a comprehensive nuclear receptor atlas of human choroidal endothelial cells and freshly isolated choroidal tissue by examining the expression levels of all members of this transcription family using quantitative real time PCR. Given the close relationship between the choroid and retinal pigment epithelium (RPE), this data was cross-referenced with the expression profile of nuclear receptors in human RPE cells, to discover potential overlap versus cell-specific nuclear receptor expression. Finally, to identify candidate receptors that may participate in the pathobiology of AMD, we cataloged nuclear receptor expression in a murine model of wet AMD, from which we discovered a subset of nuclear receptors differentially regulated following neovascularization. Overall, these databases serve as useful resources establishing the influence of nuclear receptor signaling pathways on the outer vascular tissue of the eye, while providing a list of receptors, for more focused investigations in the future, to determine their suitability as potential therapeutic targets for diseases, in which the choroid is affected.

Synergistic Effect of Combined Sub-Tenon Triamcinolone and Intravitreal Anti-VEGF Therapy for Uveitic Macular Edema

Purpose

To investigate effects of intravitreal anti-VEGF in combination therapy with sub-Tenon triamcinolone acetonide (STA) injection for uveitic macular edema (UME).

Design

A single-center, retrospective cohort study.

Methods

The medical records were obtained for 65 eyes of 65 patients with UME. Of which, 32 eyes received combined anti-VEGF with STA injection, and 33 eyes received 40 mg of STA injection alone. The primary outcome was the reduction of central macular thickness (CMT) measured with optical coherence tomography (OCT). Resolution rate of clinical UME and changes of best corrected visual acuity (BCVA) over 24 weeks were secondary outcomes.

Results

There was a significantly greater reduction of CMT with the combination treatment than with STA alone at 1-week (β = −157.9, P < 0.001) and 1-month (β = −53.1, P = 0.019) after injection. The cumulative incidence of macular edema resolution of all eyes was 87.7%, with 90.6% (29/32) in the combined group and 84.8% (28/33) in the STA group, respectively. More incidence of UME resolution was observed in the combined group than the STA group after 1 week (71.9% vs 15.2%, P < 0.001) and 4 weeks (84.4% vs 54.5%, P = 0.009), respectively. BCVA was better for the combination treatment than STA alone at 1-week (β = −0.085, P = 0.070) and 1-month (β = −0.108, P = 0.019) after injection, respectively. Increased intraocular pressure (>25 mmHg) was observed in 4 eyes (12.5%) in the combined group and 5 eyes (15.2%) in the STA group, respectively.

Conclusion

Combined intravitreal anti-VEGF and STA is superior to STA alone for reduction of UME and visual restoration. Addition of anti-VEGF did not increase risk for steroid-induced elevation of intraocular pressure over 6 months.

Protection against light-induced retinal degeneration via dual anti-inflammatory and anti-angiogenic functions of thrombospondin-1

BACKGROUND AND PURPOSE

Retinal photodamage is a high-risk factor for age-related macular degeneration (AMD), the leading cause of irreversible blindness worldwide. However, both the pathogenesis and effective therapies for retinal photodamage are still unclear and debated.

EXPERIMENTAL APPROACH

The anti-inflammatory effects of thrombospondin-1 on blue light-induced inflammation in ARPE-19 cells and in retinal inflammation were evaluated. Furthermore, the anti-angiogenic effects of thrombospondin-1 on human microvascular endothelial cells (hMEC-1 cells) and a laser-induced choroidal neovascularisation (CNV) mouse model were evaluated. in vitro experiments, including western blotting, immunocytochemistry, migration assays and tube formation assays, as well as in vivo experiments, including immunofluorescence, visual electrophysiology, spectral-domain optical coherence tomography, and fluorescein angiography, were employed to evaluate the anti-inflammatory and anti-angiogenic effects of thrombospondin-1.

KEY RESULTS

Specific effects of blue light-induced retinal inflammation and pathological angiogenesis were reflected by up-regulation of pro-inflammatory factors and activation of angiogenic responses, predominantly regulated by the NF-κB and VEGFR2 pathways respectively. During the blue light-induced pathological progress, THBS-1 derived from retinal pigment epithelium down-regulated proteomics and biological assays. Thrombospondin-1 treatment also suppressed inflammatory infiltration and neovascular leakage. The protective effect of Thrombospondin-1 was additionally demonstrated by a substantial rescue of visual function. Mechanistically, thrombospondin-1 reversed blue light-induced retinal inflammation and angiogenesis by blocking the activated NF-κB and VEGFR2 pathways, respectively.

CONCLUSION AND IMPLICATIONS

Thrombospondin-1, with dual anti-inflammatory and anti-neovascularisation properties, is a promising agent for protection against blue light-induced retinal damage and retinal degenerative disorders which are pathologically associated with inflammatory and angiogenic progress.

Clinical factors contributing to postoperative aqueous flare intensity after 27-gauge pars plana vitrectomy for the primary rhegmatogenous retinal detachment

PURPOSE

To investigate the perioperative clinical factors, which contribute to the postsurgical aqueous flare intensity (AFI) following 27-gauge pars plana vitrectomy (27GPPV) for primary rhegmatogenous retinal detachment (RRD).

STUDY DESIGN

Retrospective clinical study.

METHODS

We performed retrospective analyses of the medical records of 47 eyes of 47 patients with primary RRD who had undergone 27GPPV with a wide-angle viewing system. AFI was measured preoperatively and 1 week, 1 month, 3 months, 6 months, and 12 months after the surgery.

RESULTS

AFI was significantly increased 1 week after the surgery (p<0.01) and then decreased overtime. At 6 months after surgery it was still statistically significantly higher than preoperative AFI (p=0.03). There was no statistical difference between preoperative AFI and that at 12 months following surgery. Multiple regression analyses revealed that the number of retinal photocoagulations and the performance of scleral indentation had significant positive correlation with AFI at 1 week, 1 month, 3 months, and 6 months, and at 1 month and 3 months after the surgery, respectively.

CONCLUSION

Intraoperative retinal photocoagulation and scleral indentation are probable causes of increased AFI after 27G PPV for RRD.

Effect of intravitreal or sub-tenon triamcinolone acetonide injection at completion of vitrectomy on peripheral retinochoroidal thickness in eyes with proliferative diabetic retinopathy

The effect of triamcinolone acetonide (TA) on the peripheral retinochoroidal thickness was determined after pars plana vitrectomy (PPV) with scatter photocoagulation in eyes with proliferative diabetic retinopathy. The peripheral retinochoroidal thickness was measured at 5 mm from the limbus in the four quadrants using anterior segment optical coherence tomography before, and 3 days, and 1 and 2 weeks after the surgery. The total peripheral thickness was significantly thicker than the baseline thickness after PPV alone (P < 0.001; 18 eyes), PPV combined with intravitreal TA injection (IVTA; P = 0.011; 19 eyes), and PPV combined with sub-tenon TA injection (STTA; P = 0001; 23 eyes). The total peripheral thickness in the PPV group at 3 days after surgery was significantly thicker than that of the PPV + IVTA (P = 0.015) and of the PPV + STTA groups (P = 0.016). Multiple linear regression analyses showed that the injection of TA by the two routes and the number of photocoagulation burns were significantly correlated with the total peripheral thicknesses at 3 days after the surgery. The results indicate that the PPV with large number of intraoperative scatter photocoagulation burns caused an increase in the total peripheral thickness and an administration of either IVTA and STTA can reduced the degree of thickening.

Posterior subtenon infusion of triamcinolone acetonide as adjunctive treatment to panretinal photocoagulation using pattern scan laser for diabetic retinopathy

PURPOSE

To estimate the effect of sub-Tenon's capsule triamcinolone acetonide injection (STTA) combined with panretinal photocoagulation (PRP) using pattern scan laser (PSL) for high risk non-proliferative diabetic retinopathy (NPDR), in terms of the inflammation and the progression of diabetic macular edema (DME).

STUDY DESIGN

Retrospective comparative analysis.

METHODS

NPDR patients who underwent PRP using PSL with (STTA+PSL group, n=24) or without (PSL group, n=19) pretreatment of STTA were enrolled. We measured anterior flare intensity (AFI) and central retinal thickness (CRT) at day of STTA (day 0), and at 1, 3, 7, 11 and 15 weeks.

RESULTS

The CRT of the STTA+PSL group was significantly lower than that of the PSL group at 7 (308.15±69.16 μm versus 340.21±77.91 μm, p = 0.04), 11 (283.8±60.75 μm versus 335.7±67.70 μm, p = 0.01) and 15 weeks (281.13±35.29 μm versus 316.58±54.89 μm, p = 0.02). AFI levels in the STTA+PSL group were significantly lower than those in the PSL group at 11 (10.47±3.40 versus 15.85±8.38, p = 0.007) and 15 weeks (11.38±3.31 versus 14.37±3.85, p = 0.009). The significant improvement in CRT from baseline was noticed through the observational periods in STTA+PSL group, but not in the PSL group.

CONCLUSION

Pretreatment of STTA has the potential to not only prevent the worsening of DME, but also reduce the CRT and AFI of eyes with NPDR after PRP using PSL.

Effect of 0.05% Difluprednate Ophthalmic Emulsion on Proinflammatory Cytokine Levels After Retinal Laser Photocoagulation in Rabbits

PURPOSE

We aimed to evaluate the effect of the topical application of a strong corticosteroid, difluprednate, on the levels of inflammatory and angiogenic cytokine in the vitreous and aqueous humor after laser photocoagulation.

METHODS

Pigmented rabbits were treated with retinal laser photocoagulation and divided into 4 groups, namely control (no additional treatment), topical application of difluprednate 0.05%, betamethasone sodium phosphate 0.1%, and sub-Tenon injection of triamcinolone acetonide (STTA). Samples of vitreous and aqueous humor were collected on posttreatment days 0, 1, 7, and 14. The levels of intraocular vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), and monocyte chemotactic protein-1 (MCP-1) were measured using an immunoassay. Intraocular pressure (IOP) was monitored in each group.

RESULTS

VEGF, IL-6, ICAM-1, and MCP-1 were significantly elevated on day 1 and were reduced in both the vitreous and aqueous humor following topical application of difluprednate and STTA. Topical betamethasone reduced their levels in the aqueous humor but not in the vitreous. A significant increase of IOP induced by difluprednate returned to control levels after withdrawal of administration.

CONCLUSION

Although the elevation of IOP was an expected, manageable side effect, topical application of difluprednate was more effective than STTA and betamethasone for reducing inflammatory cytokine levels after laser treatment.

Glucocorticoid receptor signaling in the eye

Glucocorticoids (GCs) are essential steroid hormones that regulate numerous metabolic and homeostatic functions in almost all physiological systems. Synthetic glucocorticoids are among the most commonly prescribed drugs for the treatment of various conditions including autoimmune, allergic and inflammatory diseases. Glucocorticoids are mainly used for their potent anti-inflammatory and immunosuppressive activities mediated through signal transduction by their nuclear receptor, the glucocorticoid receptor (GR). Emerging evidence showing that diverse physiological and therapeutic actions of glucocorticoids are tissue-, cell-, and sex-specific, suggests more complex actions of glucocorticoids than previously anticipated. While several synthetic glucocorticoids are widely used in the ophthalmology clinic for the treatment of several ocular diseases, little is yet known about the mechanism of glucocorticoid signaling in different layers of the eye. GR has been shown to be expressed in different cell types of the eye such as cornea, lens, and retina, suggesting an important role of GR signaling in the physiology of these ocular tissues. In this review, we provide an update on the recent findings from in vitro and in vivo studies reported in the last 5 years that aim at understanding the role of GR signaling specifically in the eye. Advances in studying the physiological effects of glucocorticoids in the eye are vital for the elaboration of optimized and targeted GC therapies with potent anti-inflammatory potential while minimizing adverse effects.

Effect of intravitreal triamcinolone acetonide injection at the end of vitrectomy for vitreous haemorrhage related to proliferative diabetic retinopathy

Background/Aims

To investigate whether intravitreal injection of triamcinolone acetonide (IVTA) combined with vitrectomy prevents postoperative inflammation in patients with vitreous haemorrhage (VH) due to proliferative diabetic retinopathy (PDR).

Methods

This prospective, multicentre, randomised study conducted at seven sites in Japan enrolled patients diagnosed as having VH following PDR. Patients underwent vitrectomy with (IVTA+VIT group) or without (VIT group) IVTA at the end of the surgery. Anterior flare intensity (AFI), central retinal thickness (CRT), best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were measured before and at 3 days, 1 week, 1, 3 and 6 months after surgery and compared.

Results

Number of patients who completed 6 months of follow-up was 40 and 41 in VIT group and IVTA+VIT group, respectively. AFI was significantly higher in the VIT group than in the IVTA+VIT group at 3 days (P=0.033), 1 week (P=0.019) and 1 month (P=0.037). There were no significant differences in CRT, BCVA and IOP between the groups through the observational periods. In the cases with macular oedema >350 µm of CRT at 3 days, CRT was significantly lower in the IVTA+VIT group than in the VIT group at 1 month (P=0.041).

Conclusions

IVTA combined with vitrectomy and cataract surgery contributed to inhibit the postoperative inflammation in patients with VH due to PDR. The effect of IVTA in the reduction of diabetic macular oedema may be limited to the early stage after surgery.

Trial registration number

UMIN000020376, Post-results.

New model of proliferative vitreoretinopathy in rabbit for drug delivery and pharmacodynamic studies

Blinding retinal diseases become more epidemic as the population ages. These diseases, such as diabetic retinopathy and macular edema, are of chronic nature and require protracted drug presence at the disease site. A sustained intravitreal porous silicon delivery system with dexamethasone (pSiO₂-COO-DEX) was evaluated in a new rabbit model of proliferative vitreoretinopathy (PVR) in a real treatment design. In contrast to the pretreatment design model, pSiO₂-COO-DEX was intravitreally injected into the eyes with active inflammation. Subretinal injection of vascular endothelial growth factor (VEGF) and Matrigel induced a late-onset vitreoretinal inflammation that gradually developed into PVR. This method mimics the human disease better than PVR induced by either intravitreal cell injection or trauma. The pSiO₂-COO-DEX intervened eyes had minimal PVR, while balanced saline solution or free dexamethasone intervened eyes had significantly more PVR formation. In addition, adding VEGF to the Matrigel for subretinal injection induced greater inflammation and retinal neovascularization in comparison to only Matrigel injected under the medullary ray. Clinical and pathological examinations, including fundus fluorescein angiography and optical coherence tomography, confirmed these changes. In the current study, neither subretinal injection of Matrigel or subretinal injection of VEGF and Matrigel induced choroidal neovascularization. However, the current PVR model demonstrates a chronic course with moderate severity, which may be useful for drug screening studies.

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.

Influence of baseline diabetic retinopathy status on initial anatomical response of intravitreal ranibizumab therapy for diabetic macular oedema

PurposeIntraocular vascular endothelial growth factor (VEGF) levels increases with the severity of diabetic retinopathy. Response of diabetic macular oedema (DMO) to ranibizumab is driven by VEGF suppression. We hypothesised that the initial reduction of central macular thickness by ranibizumab should be maximum in severe diabetic retinopathy until the levels of VEGF decreases to the levels observed in eyes with mild retinopathy.MethodsConsecutive patients with centre-involving DMO (central subfield thickness (CSFT)>300 μm) who had three consecutive monthly ranibizumab injections followed by as needed therapy were included. Retinopathy status was graded as mild non-proliferative diabetic retinopathy (NPDR) (G1), moderate to severe NPDR with no prior panretinal photocoagulation (G2), and treated PDR (G3).ResultsTwo hundred and thirty-nine eyes from 204 patients with a mean age of 64.9 years were included. The distribution was 31.4 G1, 32.2 G2, and 36.4% G3. Mean baseline CSFT for all eyes was 458.5±110.8 μm. Baseline CSFT for G1, G2, and G3, respectively, were 437.6±90.9, 472.3±109.8, and 464.7±124.9 μm (P=0.2155). Mean change in CSFT after three consecutive injections was 128.5±116.6 μm. The mean changes were 95.8±101.4 μm for G1, 137.2±112.9 μm for G2, and 148.9±126.9 μm for G3. The changes in CSFT between groups adjusted for baseline CSFT were statistically significant (P=0.0473). At 6 and 12 months after a mean of 4.5 and 7.7 injections, the changes between groups were no longer significant, P=0.4783 and P=0.8271, respectively.ConclusionsThe initial anatomical response of DMO with intravitreal ranibizumab injections was maximum in eyes with treated PDR, suggesting that the higher the VEGF levels, the better the response with ranibizumab.