Triple therapy for neovascular age-related macular degeneration using single-session photodynamic therapy combined with intravitreal bevacizumab and triamcinolone

Combinations of Photodynamic Therapy with Other Minimally Invasive Therapeutic Technologies against Cancer and Microbial Infections

The rapid rise in research and development following the discovery of photodynamic therapy to establish novel photosensitizers and overcome the limitations of the technology soon after its clinical translation has given rise to a few significant milestones. These include several novel generations of photosensitizers, the widening of the scope of applications, leveraging of the offerings of nanotechnology for greater efficacy, selectivity for the disease over host tissue and cells, the advent of combination therapies with other similarly minimally invasive therapeutic technologies, the use of stimulus-responsive delivery and disease targeting, and greater penetration depth of the activation energy. Brought together, all these milestones have contributed to the significant enhancement of what is still arguably a novel technology. Yet the major applications of photodynamic therapy still remain firmly located in neoplasms, from where most of the new innovations appear to launch to other areas, such as microbial, fungal, viral, acne, wet age-related macular degeneration, atherosclerosis, psoriasis, environmental sanitization, pest control, and dermatology. Three main value propositions of combinations of photodynamic therapy include the synergistic and additive enhancement of efficacy, the relatively low emergence of resistance and its rapid development as a targeted and high-precision therapy. Combinations with established methods such as chemotherapy and radiotherapy and demonstrated applications in mop-up surgery promise to enhance these top three clinical tools. From published in vitro and preclinical studies, clinical trials and applications, and postclinical case studies, seven combinations with photodynamic therapy have become prominent research interests because they are potentially easily applied, showing enhanced efficacy, and are rapidly translating to the clinic. These include combinations with chemotherapy, photothermal therapy, magnetic hyperthermia, cold plasma therapy, sonodynamic therapy, immunotherapy, and radiotherapy. Photochemical internalization is a critical mechanism for some combinations.

Two-year clinical outcomes of triple therapy with photodynamic therapy, anti-vascular endothelial growth factor agent, and triamcinolone acetonide for neovascular age-related macular degeneration

PURPOSE

To analyze the 2-year treatment outcomes of triple therapy with standard-fluence photodynamic therapy (PDT), intravitreal injection of ranibizumab (IVR)/aflibercept (IVA), and sub-tenon injection of triamcinolone acetonide (STTA) for neovascular age-related macular degeneration (nAMD) in Japanese patients.

STUDY DESIGN

A retrospective, clinical case-series study.

METHODS

Forty-four eyes of 44 patients with treatment-naïve nAMD followed for more than 24 months were evaluated. Initial treatment was given with triple therapy and retreatment with IVR/IVA as a pro re nata regimen. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), the number of treatments, and intraocular pressure elevation were analyzed.

RESULTS

The mean age was 73.3 ± 10.0 years. The mean BCVA significantly improved from 0.61 ± 0.30 at baseline to 0.50 ± 0.46 at 24 months (p = 0.034). CRT significantly improved from 373 ± 162 μm at baseline to 200 ± 107 μm at 24 months (p < 0.001). The number of treatments given during the 2-year treatment period was 2.7 ± 1.8. No retreatments were necessary in 18 of 44 eyes (40.9%), with no significant difference between IVR (46.4%) or IVA (31.3%) used during the 2-year follow-up of triple therapy (p = 0.51). Four eyes (9.1%) temporarily required glaucoma eye drop treatments.

CONCLUSION

In nAMD patients, induction treatment with triple therapy resulted in approximately 40% of the patients requiring no retreatment for 2 years. The type of anti-VEGF agents used made no difference in the results.

Hyaluronic Acid-PEG-Based Diels-Alder In Situ Forming Hydrogels for Sustained Intraocular Delivery of Bevacizumab

Retinal diseases are the leading cause of visual impairment worldwide. The effectiveness of antibodies for the treatment of retinal diseases has been demonstrated. Despite the clinical success, achieving sufficiently high concentrations of these protein therapeutics at the target tissue for an extended period is challenging. Patients suffering from macular degeneration often receive injections once per month. Therefore, there is a growing need for suitable systems that can help reduce the number of injections and adverse effects while improving patient complacency. This study systematically characterized degradable "in situ" forming hydrogels that can be easily injected into the vitreous cavity using a small needle (29G). After intravitreal injection, the formulation is designed to undergo a sol-gel phase transition at the administration site to obtain an intraocular depot system for long-term sustained release of bioactives. A Diels-Alder reaction was exploited to crosslink hyaluronic acid-bearing furan groups (HAFU) with 4 arm-PEG10K-maleimide (4APM), yielding stable hydrogels. Here, a systematic investigation of the effects of polymer composition and the ratio between functional groups on the physicochemical properties of hydrogels was performed to select the most suitable formulation for protein delivery. Rheological analysis showed rapid hydrogel formation, with the fastest gel formation within 5 min after mixing the hydrogel precursors. In this study, the mechanical properties of an ex vivo intravitreally formed hydrogel were investigated and compared to the in vitro fabricated samples. Swelling and degradation studies showed that the hydrogels are biodegradable by the retro-Diels-Alder reaction under physiological conditions. The 4APM-HAFU (ratio 1:5) hydrogel formulation showed sustained release of bevacizumab > 400 days by a combination of diffusion, swelling, and degradation. A bioassay showed that the released bevacizumab remained bioactive. The hydrogel platform described in this study offers high potential for the sustained release of therapeutic antibodies to treat ocular diseases.

Nanosuspension-loaded dissolving bilayer microneedles for hydrophobic drug delivery to the posterior segment of the eye

Intravitreal injections (IVT) are regarded as the gold standard for effective delivery of hydrophobic drugs to the back of the eye. However, as a highly invasive procedure, the injection itself may lead to poor patient compliance and severe complications. In this research work, a hybrid system of nanosuspensions (NS) and dissolving microneedles (MNs) was developed as an alternative to conventional hypodermic needles used in IVT for minimally invasive transscleral delivery of hydrophobic drugs. NS of a hydrophobic drug, triamcinolone acetonide (TA), were fabricated using a wet milling technique. TA NS optimised by central composite factorial design had a proven diameter of 246.65 ± 8.55 nm. After optimisation, TA NS were incorporated into MN arrays to form a bilayer structure by high-speed centrifugation. TA NS-loaded MNs were robust enough to pierce excised porcine sclera with insertion depth higher than 80% of the needle height and showed rapid dissolution (<3 min). In contrast, the plain TA-loaded MNs exhibited poor mechanical and insertion performances and took more than 8 min to be fully dissolved in the scleral tissue. Importantly, transscleral deposition studies showed that 56.46 ± 7.76 μg/mm² of TA was deposited into the sclera after 5 min of NS-loaded MN application, which was 4.5-fold higher than plain drug-loaded MNs (12.56 ± 2.59 μg/mm²). An ex vivo distribution study revealed that MN arrays could promote the transscleral penetration of hydrophobic molecules with higher drug concentrations observed in the deep layer of the sclera. Moreover, the developed TA NS-loaded MN array was biocompatible with ocular tissues, as demonstrated using the hens egg-chorioallantoic membrane assay and cytotoxicity test. The results presented here demonstrate that the hybrid system of NS and dissolving MNs can provide a novel and promising technology to alleviate retinal diseases in a therapeutically effective and minimally invasive manner.

Effects of Novel Anti-VEGF Agents with Intravitreal Conbercept in Diabetic Retinopathy: A Systematic Review and Meta-Analysis

To evaluate the efficacy and safety of intravitreal conbercept (IVC) for diabetic retinopathy (DR) compared with intravitreal triamcinolone acetonide (IVTA). PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, VIP database, and Wanfang database were searched from their earliest records to January 2020. We included randomized controlled trials (RCTs) evaluating the efficacy and safety of conbercept in DR patients compared with ITVA. Outcomes included the mean changes from the baseline in best corrected visual acuity (BCVA) score, central macular thickness (CMT), quality of life (QoL) over time, and the incidence of adverse events (AEs). A total of 19 RCTs involving 1,811 eyes were included in this meta-analysis. IVC might improve BCVA (WMD = 0.10, 95% CI (0.07, 0.12), P < 0.001) and reduce CMT (WMD = -102.5, 95% CI (-148.48, -56.53), P < 0.001) compared to IVTA. The incidence of AEs in patients receiving IVC was significantly lower than those receiving IVTA (RR = 0.29, 95% CI (0.21, 0.40), P < 0.001). Patients with IVC treatments acquired better self-care, mobility, social, and mental scores compared with IVTA (P < 0.001). Current evidence shows that IVC has better effects and safety than IVTA in treating DR, and it can significantly enhance the QoL of patients with DR.

Protective Effect of a Bispecific Fc-Fusion Protein on the Barrier of Human Retinal Pigment Epithelial Cells

INTRODUCTION

The aim of the study was to evaluate the protective effects of IBI302, a bispecific Fc-fusion protein that theoretically can bind vascular endothelial growth factor (VEGF), complement C3b, and C4b in the barrier of the cultured human retinal pigment epithelial (hRPE) cells.

METHODS

Primary hRPE cells were isolated and cultured to monolayer barrier. hRPE monolayers were divided into the PBS control group, VEGF-Trap group, complement receptor 1 (CR1) group, and IBI302 group. Identification of hRPE cells, barrier function, inflammation factors, and immune response products was tested by immunofluorescent staining, transepithelial resistance (TER), and ELISA.

RESULTS

IBI302 treatment significantly improved the TER of the barrier of hRPE cells after complement-activated oxidative stress compared with the PBS control group, VEGF-Trap group, and CR1 group. The maximum effect of IBI302 on protecting hRPE cell viability was observed at the concentration of 1 μg/mL. The elevated expression of VEGF, chemokine (C-C Motif) ligand 2, C3a, C5a, and membrane attack complex was reduced by IBI302.

CONCLUSION

IBI302 could protect the barrier function of hRPE cells. IBI302 might be a potentially effective drug for the RPE barrier-associated ocular diseases.

Systemic steroids for the management of choroidal neovascular membrane with pigment epithelial tear and recalcitrant subretinal fluid

A 67-year-old man was diagnosed to have dry age related macular degeneration in the right eye and a choroidalneovascular membrane (CNVM) with a large pigment epithelial detachment in the left eye, confirmed with clinical examination, angiography and optical coherence tomography scans. He received an intravitreal injection of bevacizumab in the right eye and developed a retinal pigment epithelial (RPE) tear 3 weeks later. 3 consecutive ranibizumab injections failed to clear the subretinal fluid (SRF). A course of systemic steroids was administered and this improved the vision. Subsequently, the patient received one more ranibizumab injection and the disease process resolved. The left eye corrected distance visual acuity (LE CDVA) was 20/30 at the final visit (1 year after the last injection). Systemic steroids may be a management option in patients with CNVM and RPE tear with recalcitrant SRF if there is no contraindication to their use.

Clinical observations on the use of new anti-VEGF drug, conbercept, in age-related macular degeneration therapy: a meta-analysis

PURPOSE

Conbercept is a new anti-vascular endothelial growth factor (VEGF) drug approved for the treatment of age-related macular degeneration (AMD). Although this novel drug has been widely used in clinic, unlike other anti-VEGF drugs, validation and consensus on its method of clinical application and clinical safety have not yet been achieved.

METHODS

Relevant literature was searched on PubMed, Web of Science, China National Knowledge Internet, and Wanfang Data. Stata 12.0 was used for data analysis. Random- and fixed-effect models were employed to evaluate heterogeneity. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were utilized to measure the improvement of AMD patients.

RESULTS

In this study, we analyzed conbercept administration and compared its application with other control clinical methods for AMD treatment. Ranibizumab, triamcinolone, and traditional transpupillary thermotherapy (TTT) were administered in the control group. No differences were found in the BCVA and CRT improvement between the groups treated with conbercept and ranibizumab. However, the conbercept group had a lower serum VEGF level. After 3 months of treatment, conbercept led to a more significant BCVA and CRT improvement than triamcinolone. A more considerable BCVA improvement was observed in the group treated with conbercept than in the group treated with TTT. Moreover, even 6 months after the treatment, the effect of conbercept on CRT improvement was still more pronounced than that of TTT.

CONCLUSION

In AMD patients, conbercept exerts considerably more positive effects on the long-term BCVA and CRT improvement than triamcinolone and TTT. The serum VEGF level in the conbercept group was lower than that in the ranibizumab group.

Combination verteporfin photodynamic therapy ranibizumab-dexamethasone in choroidal neovascularization due to age-related macular degeneration: results of a phase II randomized trial

PURPOSE

To assess whether combination therapy (CT) reduces retreatments when compared to ranibizumab monotherapy (RM), while safely maintaining similar vision outcomes.

METHODS

In this 24-month trial, patients with age-related macular degeneration (AMD) were randomized to 1) quarter-fluence or 2) half-fluence triple therapy (verteporfin photodynamic therapy [vPDT] + ranibizumab + dexamethasone), 3) half-fluence double therapy (vPDT + ranibizumab), or 4) RM. The primary outcomes were number of retreatment visits and change from baseline in visual acuity (VA) at 12 months.

RESULTS

One hundred sixty-two subjects enrolled. There were 4.0 (P=0.02), 3.2 (P<0.001), 4.1 (P=0.03), and 5.7 retreatment visits through month 12, and 5.9 (P=0.03), 4.3 (P<0.001), 5.9 (P=0.02) and 8.7 through month 24, in groups 1, 2, 3, and 4, respectively (P-value comparing with RM). Month 12 VA score change from baseline (95% confidence interval) was +3.6 (-0.9 to +8.1), +6.8 (+2.4 to +11.1), +5.0 (+0.6 to +9.3), and +6.5 (+1.7 to +11.4), respectively.

CONCLUSION

CT resulted in significantly fewer retreatment visits than a RM regimen at months 12 and 24. VA results appeared similar although wide confidence intervals preclude conclusions regarding vision outcomes.

Photodynamic Therapy and Intravitreal Bevacizumab with Versus without Triamcinolone for Neovascular Age-related Macular Degeneration; a Randomized Clinical Trial

PURPOSE

To compare the outcomes of photodynamic therapy (PDT) combined with intravitreal bevacizumab (IVB) with versus without intravitreal triamcinolone (IVT) in neovascular age-related macular degeneration (AMD).

METHODS

Eighty-four eyes with active CNV secondary to AMD with no prior treatment were enrolled and followed for 1-year. Eligible eyes were randomly assigned to either PDT/IVB or PDT/IVB/IVT. The main outcome measure was change in best-corrected visual acuity (BCVA).

RESULTS

Mean patient age was 71 ± 9 years. BCVA changes from baseline were statistically significant in both study arms at all follow-up intervals, however no significant difference was observed between the two groups regarding BCVA changes at week 12 (95% CI:-0.11-0.12 LogMAR) and other time points (all P > 0.6). Mixed model analysis revealed a significant effect from age (P < 0.001), pigment epithelial detachment (P = 0.009) and baseline BCVA (P < 0.001) on visual improvement. Significant central macular thickness (CMT) reduction occurred at all-time points as compared to baseline in both groups which was comparable between the study arms. There was no significant difference between the study arms in terms of retreatment rate (P = 0.1) and survival to the first repeat IVB injection (P = 0.065).

CONCLUSION

Additional low-dose IVT to a PDT/IVB regimen for neovascular AMD provided no beneficial effects in terms BCVA or CMT, yet demonstrated a trend toward extending the injection-free period.

Future therapies of wet age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly population, and the prevalence of the disease increases exponentially with every decade after the age of 50 years. While VEGF inhibitors are promising drugs for treating patients with ocular neovascularization, there are limitations to their potential for improving vision in AMD patients. Thus, future therapies are required to have the potential to improve visual outcomes. This paper will summarize the future strategies and therapeutic targets that are aimed at enhancing the efficacy and duration of effect of antiangiogenic strategies.

Targeted radiotherapy with gold nanoparticles: current status and future perspectives

Radiation therapy (RT) is the treatment of cancer and other diseases with ionizing radiation. The ultimate goal of RT is to destroy all the disease cells while sparing healthy tissue. Towards this goal, RT has advanced significantly over the past few decades in part due to new technologies including: multileaf collimator-assisted modulation of radiation beams, improved computer-assisted inverse treatment planning, image guidance, robotics with more precision, better motion management strategies, stereotactic treatments and hypofractionation. With recent advances in nanotechnology, targeted RT with gold nanoparticles (GNPs) is actively being investigated as a means to further increase the RT therapeutic ratio. In this review, we summarize the current status of research and development towards the use of GNPs to enhance RT. We highlight the promising emerging modalities for targeted RT with GNPs and the corresponding preclinical evidence supporting such promise towards potential clinical translation. Future prospects and perspectives are discussed.

Management of recurrent inflammatory choroidal neovascular membrane secondary to Vogt-Koyanagi-Harada syndrome, using combined intravitreal injection of bevacizumab and triamcinolone acetate

The purpose of this report is to evaluate the efficacy and safety of combined intravitreal injection of bevacizumab and intravitreal triamcinolone acetonide (IVTA) for recurrent inflammatory choroidal neovascular membrane (CNVM). It was a prospective interventional study of a young female, who was a known case of Vogt-Koyanagi-Harada syndrome. She presented with an inflammatory choroidal neovascualar membrane and signs of panuveitis in the right eye. She underwent a complete ophthalmic examination. She was given intravitreal injection of bevacizumab and IVTA at different sites. There was complete regression of CNVM and ocular inflammation within a week. After six months, she had recurrence of CNVM in the same eye, which was treated similarly. There was a complete resolution of CNVM and ocular inflammation after the combination therapy and systemic steroids, until one year of follow-up. No serious systemic or ocular adverse events were noted. Combination therapy appears to be an effective and safe method in the management of recurrent inflammatory CNVM.

Acute glaucoma in a patient with an Artisan® due to trabecular blockage after combined intravitreal treatment for macular oedema

CASE REPORT

We present a 71-year-old patient with an Artisan(®) implant and macular oedema associated with unsatisfactory response to repeated intravitreal corticosteroids. An intravitreal Trigon(®) and Avastin(®) combined injection was given, and acute glaucoma developed. Anterior chamber washout was performed to resolve the rise in intraocular pressure. In spite of an excellent macular response, this was only temporary, and the corneal endothelium, which had remained competent so far, suffered irreversible damage.

DISCUSSION

The combination of both treatments, along with the particular anatomic features in these patients, may have been precipitating factors in this unfortunate outcome.

Choroidal infarction after photodynamic therapy combined with bevacizumab and triamcinolone reversed by tissue plasminogen activator: case report

PURPOSE

To present a case of choroidal infarction after combined therapy of photodynamic therapy, intravitreal bevacizumab, and sub-Tenon triamcinolone injection salvaged by tissue plasminogen activator administration.

METHODS

Interventional case report.

RESULTS

Combined therapy of full-fluence photodynamic therapy, intravitreal bevacizumab, and sub-Tenon triamcinolone injection was given on the same day to treat neovascular age-related macular degeneration in an 82-year-old patient. Subsequent acute visual loss and marked macular edema as a result of choroidal infarction were noted. Intravitreal and sub-Tenon administration of tissue plasminogen activator were performed 9 days later to salvage the choroidal infarction, and visual improvement was noted. Fundoscopy and optical coherent tomography showed almost complete resolution of macular edema. Indocyanine green angiography revealed reperfusion of the choroidal vessels.

CONCLUSION

Choroidal infarction may happen after combined therapy. Tissue plasminogen activator administration may reverse the infarction and help visual recovery.

Photodynamic therapy combined with intravitreal bevacizumab in a patient with choroidal neovascularization secondary to choroidal osteoma

Choroidal osteoma is a benign ossified tumor that is found predominantly in healthy young women during their second and third decades of life. The lesions are white-to-cream or orange in color, are located in the peripapillary and macular areas, and are unilateral in most patients. The symptoms of choroidal osteoma include decreased visual acuity and metamorphopsia or scotoma corresponding to the location of the osteoma, but some patients have no symptoms. Prognosis of vision varies according to tumor location, retinal pigment epithelial and sensory retinal degeneration, subretinal fluid and hemorrhage, and development of a subretinal neovascular membrane.

A prospective study on different methods for the treatment of choroidal neovascularization. The efficacy of verteporfin photodynamic therapy, intravitreal bevacizumab and transpupillary thermotherapy in patients with neovascular age-related macular degeneration

Background

The aim of this study was to compare the efficacy of verteporfin photodynamic therapy (PDT), intravitreal injections of bevacizumab (IVB) and transpupillary thermotherapy (TTT) in patients with neovascular age-related macular degeneration (AMD).

Material/Methods

The study design was a prospective, interventional, comparative case series. Between December 2006 and March 2009, 426 eyes of 426 consecutive patients presenting with neovascular AMD were included into the study. Patients presented with subfoveal CNV predominantly classic, minimally classic, and occult with no classic component; lesion size less than 5000 μm in the greatest linear dimension, and the area of hemorrhages ≤1/3 were randomized to receive either PDT (group I) or IVB (group II) in a 1:1 ratio. Other patients with CNV were included into the group III and received TTT.

Results

One hundred eyes were treated with PDT. Mean baseline logMAR BCVA was 0.62 and final visual acuity decreased to 0.74 (p<0.05, Wilcoxon test); 104 eyes were treated with IVB. Mean baseline BCVA was 0.82 and final visual acuity increased to 0.79 (p>0.05, Wilcoxon test); 222 patients were treated with TTT. Mean baseline BCVA was 1.10 and final visual acuity decreased to 1.15 (p>0.05, Wilcoxon test). Among all eyes the average number of treatment sessions was 2.34 (SD 1.17).

Conclusions

Our study shows that IVB injections had the best efficacy in the improvement of final BCVA. However, both IVB and TTT demonstrated good stabilization of vision. Although after PDT final BCVA was significantly worse from baseline, it may also be beneficial for some patients with neovascular age-related macular degeneration.

Gold nanoparticle enhancement of stereotactic radiosurgery for neovascular age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries for people over the age of 50. In this work, the dosimetric feasibility of using gold nanoparticles (AuNP) as radiosensitizers to enhance kilovoltage stereotactic radiosurgery for neovascular AMD is investigated. Microdosimetry calculations at the sub-cellular level were carried out to estimate the radiation dose enhancement to individual nuclei in neovascular AMD endothelial cells (nDEF) due to photon-induced photo-/Auger electrons from x-ray-irradiated AuNP. The nDEF represents the ratio of radiation doses to the endothelial cell nuclei with and without AuNP. The calculations were carried out for a range of feasible AuNP local concentrations using the clinically applicable 100 kVp x-ray beam parameters employed by a commercially available x-ray therapy system. The results revealed nDEF values of 1.30-3.26 for the investigated concentration range of 1-7 mg g(-1), respectively. In comparison, for the same concentration range, nDEF values of 1.32-3.40, 1.31-3.33, 1.29-3.19, 1.28-3.12 were calculated for 80, 90, 110 and 120 kVp x-rays, respectively. Meanwhile, calculations as a function of distance from the AuNP showed that the dose enhancement, for 100 kVp, is markedly confined to the targeted neovascular AMD endothelial cells where AuNP are localized. These findings provide impetus for considering the application of AuNP to enhance therapeutic efficacy during stereotactic radiosurgery for neovascular AMD.

A prospective pilot study comparing combined intravitreal ranibizumab and half-fluence photodynamic therapy with ranibizumab monotherapy in the treatment of neovascular age-related macular degeneration

Purpose

This prospective multi-center pilot study compares the use of half-fluence photodynamic therapy combined with ranibizumab with ranibizumab monotherapy for the treatment of neovascular age-related macular degeneration.

Methods

All patients presenting with untreated subfoveal neovascular age-related macular degeneration were considered for inclusion. Patients were randomized to receive either ranibizumab with half-fluence photodynamic therapy or ranibizumab alone. Patients in the ranibizumab alone group were given three consecutive monthly ranibizumab injections and were followed monthly. They were treated with ranibizumab as needed, based on clinical discretion, using vision and optical coherence tomography. Patients in the combined group were given one same-day combined ranibizumab and half-fluence (25 j/cm²) photodynamic therapy treatment and were treated monthly as needed. Outcomes included changes in standardized visual acuity, optical coherence tomography foveal thickness, and percentage of as-needed injections to maintenance examinations.

Results

Fifty-six out of 60 enrolled patients completed the twelve month primary outcome visit; this consisted of 27 patients receiving ranibizumab alone and 29 receiving combined treatment. The average age was 79.1 for the ranibizumab alone group and 79.3 for the combined group. The mean visual acuity in the ranibizumab alone group improved from 52.9 Early Treatment of Diabetic Retinopathy letters initially to 62.8 letters at twelve months. The mean visual acuity in the combined group improved from 49.2 letters to 51.8 letters at twelve months. The differences in visual acuity improvements were not statistically significant based on a two-tailed t-test (P = 0.2). Due to the presence of outliers in each group, a Mann–Whitney U test was performed to confirm the results (U = 325; P = 0.28). The mean optical coherence tomography foveal thickness improved 92.5 microns and 106.7 microns in the ranibizumab alone and the combined group, respectively. The difference was not significant based on a two-tailed t-test (P = 0.6). The ranibizumab alone group received an average of 6.8 injections, while the combined group received an average of three injections. This difference was not significant based on a chi-square test (P = 0.11).

Conclusion

The groups appeared similar based on statistical analysis, but larger studies are needed to determine possible small differences between combination therapy and monotherapy.

Two-year outcome of photodynamic therapy combined with intravitreal injection of bevacizumab and triamcinolone acetonide for polypoidal choroidal vasculopathy

PURPOSE

To compare the 2-year results after photodynamic therapy (PDT) alone and PDT combined with intravitreal injections of bevacizumab and triamcinolone acetonide (triple therapy) for polypoidal choroidal vasculopathy (PCV).

METHODS

We retrospectively reviewed the medical records of 40 consecutive patients (40 eyes) with subfoveal PCV. Of these 40 eyes, 16 were treated with PDT alone and 24 were treated with triple therapy.

RESULTS

The change in visual acuity in the triple therapy group was significantly better than that in the PDT group (P < 0.001). At 24 months, improvement in visual acuity was seen in only two eyes (12.5 %) of the PDT group, while it was seen in ten eyes (41.7 %) of the triple therapy group. Retreatment was given to 12 eyes (75.0 %) in the PDT group and to nine eyes (37.5 %) in the triple therapy group, although the retreatment-free period was significantly longer in the triple therapy group than in the PDT group (P < 0.001). Post-treatment vitreous hemorrhage was seen in only two eyes (12.5 %), all of which were in the PDT group.

CONCLUSION

Compared with PDT alone, triple therapy appears to reduce the postoperative hemorrhagic complications and recurrences of PCV and to improve the 2-year visual outcomes of PCV.

VEGF gene polymorphism and response to intravitreal bevacizumab and triple therapy in age-related macular degeneration

PURPOSE

To investigate the association between the vascular endothelial growth factor (VEGF) gene and response to either intravitreal bevacizumab (IVB) or photodynamic therapy with intravitreal triamcinolone acetonide and IVB (triple therapy) for neovascular age-related macular degeneration (AMD).

METHODS

The study consisted of 94 patients with neovascular AMD who underwent IVB and 79 patients with neovascular AMD who underwent triple therapy. Genotypes were determined for four selected tagging single-nucleotide polymorphism (SNP)s of the VEGF gene.

RESULTS

Of the four SNPs studied, one SNP (rs699946) was associated significantly with visual acuity (VA) changes 12 months after treatment-irrespective of whether they received IVB alone (P = 0.044) or triple therapy 0.010). Baseline VA was not significantly different among the three genotypes of rs699946 in either treatment group. There were no significant differences in the number of treatments, incidence of recurrence, or the period until the recurrence according to VEGF rs699946 genetic variant.

CONCLUSIONS

The VEGF gene SNP rs699946 was associated with response to IVB alone and to triple therapy in this study. The G allele in SNP rs699946 can thus be applied as a marker for better visual prognosis in patients with neovascular AMD who receive either IVB or triple therapy.

Oscillatory photodynamic therapy for choroidal neovascularization and central serous retinopathy; a pilot study

PURPOSE

To report the preliminary results of oscillatory photodynamic therapy (OPDT) for choroidal neovascularization (CNV) and central serous retinopathy (CSR).

METHODS

This study included 7 eyes of 6 patients with CSR (2 eyes), idiopathic CNV (2 eyes), CNV due to age-related macular degeneration (AMD) (2 eyes), and peripapillary CNV secondary to presumed ocular histoplasmosis syndrome (1 eye). Intravenous verteporfin (6 mg/m(2) body surface area) was infused over 10 minutes followed by oscillating laser (wavelength 689 nm) covering slightly beyond the entire lesion. An Area Centralis lens was applied and laser was delivered (600 mW/cm(2) fluence rate and 50 J/cm(2) dose). Intravitreal bevacizumab and dexamethasone combination therapy was used with OPDT in 4 eyes with CNV; intravitreal dexamethasone and triamcinolone acetonide were injected in the other eye with CNV. Clinical examination, funduscopy, fluorescein angiography, and optical coherence tomography (OCT) were performed at baseline and after treatment.

RESULTS

After mean follow-up of 7.1±5.1 months, visual acuity improved from 0.87±0.69 logMAR (20/160) to 0.60±0.65 logMAR (20/80) (P = 0.027); central foveal thickness decreased from 322±62.1 to 240.7±34.8 microns as measured by OCT (P = 0.018). Fluorescein angiography and OCT demonstrated cessation of vascular leakage, and resolution of hemorrhage and subretinal fluid in all eyes. No adverse events or recurrence were noted.

CONCLUSION

OPDT was effective in treating CNV lesions and CSR. OPDT may be an improvement on standard PDT due to reduced side effects, thermal damage and scarring.

The role of anti-inflammatory agents in age-related macular degeneration (AMD) treatment

Although age-related macular degeneration (AMD) is not a classic inflammatory disease like uveitis, inflammation has been found to have an important role in disease pathogenesis and progression. Innate immunity and autoimmune components, such as complement factors, chemokines, cytokines, macrophages, and ocular microglia, are believed to be heavily involved in AMD development. Targeting these specific inflammatory molecules has recently been explored in an attempt to better understand and treat AMD. Although antivascular endothelial growth factor therapy is the first line of defence against neovascular AMD, anti-inflammatory agents such as corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), immunosuppressive agents (eg, methotrexate and rapamycin), and biologics (eg, infliximab, daclizumab, and complement inhibitors) may provide an adjunct or alternative mechanism to suppress the inflammatory processes driving AMD progression. Further investigation is required to evaluate the long-term safety and efficacy of these drugs for both neovascular and non-neovascular AMD.

Current status of vascular endothelial growth factor inhibition in age-related macular degeneration

Angiogenesis, the process by which new vessels are created from pre-existing vasculature, has become the subject of intense research in recent years. Increased rates of angiogenesis are associated with several disease states, including cancer, age-related macular degeneration (AMD), psoriasis, rheumatoid arthritis, and diabetic retinopathy. Vascular endothelial growth factor (VEGF) is an important modulator of angiogenesis, and has been implicated in the pathology of a number of conditions, including AMD, diabetic retinopathy, and cancer. AMD is a progressive disease of the macula and the third major cause of blindness worldwide. If not treated appropriately, AMD can progress to involve both eyes. Until recently, the treatment options for AMD have been limited, with photodynamic therapy (PDT) the mainstay of treatment. Although PDT is effective at slowing disease progression, it rarely results in improved vision. Several therapies have been or are now being developed for neovascular AMD, with the goal of inhibiting VEGF. These VEGF inhibitors include the RNA aptamer pegaptanib, partial and full-length antibodies ranibizumab and bevacizumab, the VEGF receptor decoy aflibercept, small interfering RNA-based therapies bevasiranib and AGN 211745, sirolimus, and tyrosine kinase inhibitors, including vatalanib, pazopanib, TG 100801, TG 101095, AG 013958, and AL 39324. At present, established therapies have met with great success in reducing the vision loss associated with neovascular AMD, whereas those still under investigation offer the potential for further advances. In AMD patients, these therapies slow the rate of vision loss and in some cases increase visual acuity. Although VEGF-inhibitor therapies are a milestone in the treatment of these disease states, several concerns need to be addressed before their impact can be fully realized.

The use of intraocular corticosteroids

BACKGROUND

Diabetic macular edema (DME), cystoid macular edema (CME), age-related macular degeneration (AMD), retinal vascular occlusion (RVO) and uveitis are responsible for severe visual impairment worldwide. In some patients with these conditions, treatment with intraocular corticosteroids may be beneficial. Although off-label use of these agents has occurred for many years, novel agents including preservative-free and sustained-release intravitreal implants are currently being studied in clinical trials (CTs).

OBJECTIVE

To review the use of intraocular corticosteroids.

METHODS

Literature review.

RESULTS

Used alone, intravitreal corticosteroids may benefit disorders such as DME, RVO and uveitis compared with standard therapy or observation. Patients with AMD may benefit more from combination treatment with photodynamic therapy, intravitreal corticosteroid and intravitreal anti-VEGF injections. Intraoperative use of these agents may assist in visualization and manipulation of fine retinal structures. Sustained-release intraocular implants have been approved for severe posterior uveitis, and have shown benefits in ongoing CTs.

CONCLUSION

Although intraocular corticosteroid injections have a limited duration of action requiring frequent re-treatment, and significant side effects including cataract and glaucoma development, intraocular injections may be of benefit in certain ocular disorders. Corticosteroid implants are emerging as potential treatments for macular edema due to uveitis, DME or RVO.