Effect of vitrectomy on aqueous VEGF concentration and pharmacokinetics of bevacizumab in macaque monkeys

Comparison of the cytokines levels in aqueous humor in vitrectomized eyes versus non-vitrectomized eyes with diabetic macular edema

BACKGROUND

This study was conducted to compare concentrations of VEGF family growth factors, inflammation-related factors, and adhesion molecules in the aqueous humor of eyes with diabetic macular edema (DME), with and without prior vitrectomy.

METHODS

A total of 31 eyes were included, 11 with DME that had undergone vitrectomy, 9 with DME but without vitrectomy, and 11 from age-related cataract patients as controls. The concentrations of cytokines including TNF-α, IL-6, IL-8, IP-10, MCP-1, IFN-γ, MIP-1 α, MIP-1 β, PECAM-1, MIF, VCAM-1, ICAM-1, PIGF were quantified using Luminex Human Discovery Assay. Central macular thickness (CMT) values of all eyes were measured using optical coherence tomography (OCT).

RESULTS

(1) Vitrectomized DME eyes exhibited significantly higher levels of IL-6 and IL-8 compared to non-vitrectomized eyes (P < 0.05). (2) In vitrectomized group, after Benjamini-Hochberg correction, there was a significant positive correlation between the levels of VEGF and PlGF (rs = 0.855, P < 0.05), as well as the levels of TNF-α and IFN-γ (rs = 0.858, P < 0.05). In non-vitrectomized group, significant positive correlations were found between VEGF and PlGF levels after correcting for multiple comparisons (rs = 0.9, P < 0.05). (3) In non-vitrectomized group, the concentrations of VEGF and PlGF in aqueous humor were significantly positively correlated with CMT values (rs = 0.95, P < 0.05; rs = 0.9, P < 0.05, respectively).

CONCLUSIONS

The concentrations of IL-6 and IL-8 in the aqueous humor were significantly higher in vitrectomized DME eyes compared to nonvitrectomized DME eyes and the levels of VEGF were similar in the two groups, suggesting that inflammation after vitrectomy may be a key factor in the occurrence and development of DME.

Duration of Vascular Endothelial Growth Factor Suppression After Intravitreal Injection of Brolucizumab and Aflibercept in Macaque Eyes

Purpose: To compare the duration of vascular endothelial growth factor (VEGF) suppression in the aqueous humor of macaque eyes after intravitreal injection of brolucizumab and aflibercept. Methods: Clinical dose of intravitreal brolucizumab (IVBr; 6.0 mg/50 μL) or intravitreal aflibercept (IVA; 2 mg/50 μL) was injected into the right eye of each of 8 macaques. Aqueous humor samples (150 μL) from both eyes were obtained just before injection and on days 1, 3, 7, 14, 21, 28, 42, 56, 84, and 112 after IVBr injection or IVA injection. VEGF concentrations were measured using enzyme-linked immunosorbent assays. Results: In the injected eyes, the mean VEGF suppression durations (range) were 4.9 (3-8) weeks for IVBr injection and 6.8 (6-8) weeks for IVA injection (P = 0.04). The VEGF concentrations returned to the preinjection level in the aqueous humor at 12 weeks both after IVBr and IVA injection. In the noninjected fellow eyes, the aqueous VEGF concentrations had decreased least at 1 day after IVBr injection and at 3 days after IVA injection, but were still detectable. The VEGF concentrations in the fellow eyes returned to the preinjection level in the aqueous humor at 1 week after IVBr injection and at 2 weeks after IVA injection. Conclusions: The duration of VEGF suppression in the aqueous humor after IVBr injection may be shorter than that after IVA injection, which may be related with clinical usage.

Persistent diabetic macular edema: Definition, incidence, biomarkers, and treatment methods

Intravitreal antivascular endothelial growth factor (anti-VEGF) treatment has drastically improved the visual and anatomical outcomes in patients with diabetic macular edema (DME); however, success is not always guaranteed, and a proportion of these eyes demonstrate persistent DME (pDME) despite intensive treatment. While standardized criteria to define these treatment-resistant eyes have not yet been established, many studies refer to eyes with no clinical response or an unsatisfactory partial response as having pDME. A patient is considered to have pDME if the retinal thickness improves less than 10-25% after 6 months of treatment. A range of treatment options have been recommended for eyes with pDME, including switching anti-VEGF agents, using corticosteroids and/or antioxidant drugs in adjunct with anti-VEGF therapy, and vitrectomy. In addition, multimodal imaging of DME eyes may be advantageous in predicting the responsiveness to treatment; this is beneficial when initiating alternative therapies. We explore the literature on persistent DME regarding its defining criteria, incidence, the baseline biological markers that may be useful in anticipating the response to treatment, and the available treatment options.

Impact of the COVID-19 Pandemic on Anti-Vascular Endothelial Growth Factor Therapy for Diabetic Macular Edema in Japan

Anti-vascular endothelial growth factor (VEGF) therapy for diabetic macular edema (DME) improves visual acuity. However, repeated injections during routine outpatient visits are required to maintain this effect. The recent sudden global outbreak of coronavirus disease 2019 (COVID-19) had a major impact on daily life, including medical care, such as the provision of VEGF therapy. We retrospectively investigated the relationship between the number of anti-VEGF injections for DME and the number of new COVID-19-positive patients at 23 centers in Japan. We also surveyed ophthalmologists regarding the impact of the COVID-19 pandemic on anti-VEGF therapy. In the third and fourth waves of the pandemic, when the number of infected patients increased, the number of injections significantly decreased. In the first, third, and fourth waves, the number of injections increased significantly during the last month of each wave. Approximately 60.9% of ophthalmologists reported that the number of injections decreased after the pandemic. Of the facilities, 52.2% extended the clinic visit intervals; however, there was no significant difference in the actual number of injections given between before and after the pandemic. Although the number of injections temporarily decreased, Japanese ophthalmologists maintained the total annual number of anti-VEGF injections for DME during the pandemic.

Differences in clinical characteristics and treatment outcomes of submacular hemorrhage caused by age-related macular degeneration and retinal macroaneurysms: A multicenter survey from the Japan Clinical Retina Study (J-CREST) group

Purpose

To evaluate the clinical characteristics, treatment trends, and visual prognosis of submacular hemorrhage (SMH) secondary to neovascular age-related macular degeneration (nAMD) and retinal arterial macroaneurysm (RAM).

Methods

This retrospective study enrolled 187 Japanese patients with SMH at 10 institutions from 2015 to 2018. Medical records including SMH etiology, best-corrected visual acuity (BCVA), fundus photographs, optical coherence tomography images, and selected treatments were analyzed.

Results

Major causes of SMH were typical nAMD (tnAMD) (18%), polypoidal choroidal vasculopathy (PCV) (50%) and RAM (29%). Age, male/female ratio, baseline BCVA, central retinal thickness, and involved retinal layers were significantly different between etiologies (all P<0.0001). Treatment with anti-vascular endothelial growth factor drugs with and without intravitreal gas injection was chosen for half of eyes in the tnAMD and PCV groups, whereas vitrectomy was performed in 83.7% of eyes with RAM. The final BCVA improved significantly from baseline in the PCV and RAM groups (P = 0.0009, P<0.0001) and final BCVA was significantly better in the PCV group at a level similar to the other groups (P = 0.0007, P = 0.0008). BCVA improvement from baseline was significantly greater in the RAM group compared with the tnAMD (P = 0.0152) and PCV (P = 0.017) groups. Multivariate analysis revealed better final BCVA was significantly associated with younger age (P = 0.0054), better baseline BCVA (P = 0.0021), RAM subtype (P = 0.0446), and no tnAMD (P = 0.001).

Conclusions

The characteristics of, and treatment strategy for, SMH were different between the underlying diseases. Anti-vascular endothelial growth factor treatment with or without expansile gas was mainly chosen for SMH in tnAMD and PCV, whereas vitrectomy with gas was the most common treatment for RAM, and the higher rate for vitrectomy might result in the greater BCVA improvement in the RAM group than in the other groups. Final BCVA was better in PCV, RAM, and tnAMD, in that order, because patients with PCV were younger and had better baseline BCVA.

Prospective Comparison of Surgery Outcome Between Preoperative and Intraoperative Intravitreal Injection of Ranibizumab for Vitrectomy in Proliferative Diabetic Retinopathy Patients

INTRODUCTION

To compare the efficacy and safety of intravitreal injections of ranibizumab (IVR) before and at the end of vitrectomy in proliferative diabetic retinopathy (PDR) patients.

METHODS

A prospective comparative study was performed on 60 eyes of 52 PDR patients who received ranibizumab injection (0.5 mg/0.05 ml) 3-5 days before vitrectomy (preoperative group) and 55 eyes of 50 PDR patients who received ranibizumab injection (0.5 mg/0.05 ml) at the end of vitrectomy (intraoperative group). Intra- and postoperative indices were collected for further comparison.

RESULTS

Postoperative best-corrected visual acuity (BCVA) in preoperative group was better than in intraoperative group at 1 week after surgery (P < 0.05) but comparable at 1- and 3-month follow-up (P = 0.20 and P = 0.37, respectively). Central retinal thickness (CRT) in preoperative group was lower than in intraoperative group at 1 week postoperatively (P < 0.05), but comparable at 1- and 3-month follow-up (P = 0.39 and P = 0.77, respectively). The average surgery time was significantly shorter in preoperative group than in intraoperative group (61.50 ± 11.44 min vs. 74.49 ± 12.01 min, P < 0.01). The incidence of intraoperative bleeding was significant lower in preoperative group than in intraoperative group (21.7% vs. 40.0%, P < 0.05). Moreover, the incidence of intraocular electrocoagulation use, iatrogenic retinal breaks, relaxing retinotomy and silicone oil tamponade were all significantly lower in preoperative group than that in intraoperative group (P < 0.05, respectively). The incidences of postoperative vitreous hemorrhage (VH), neovascular glaucoma (NVG), recurrent retinal detachment, postoperative fibrovascular proliferation progression and reoperation showed no statistical differences between the two groups (P > 0.05, respectively). Both groups had no ocular or system adverse events during observation period.

CONCLUSION

In vitrectomy for PDR, preoperative IVR can significantly reduce surgery time and lower the incidence of intraoperative bleeding, intraocular electrocoagulation use, iatrogenic retinal breaks, relaxing retinotomy and silicone oil tamponade during surgery and gain short-term better postoperative BCVA and thinner CRT.

TRIAL REGISTRATION

ClinicalTrials.gov (identifier, NCT05408416).

Epimacular brachytherapy for previously treated neovascular age-related macular degeneration: month 36 results of the MERLOT randomised controlled trial

BACKGROUND/AIM

To assess the long-term safety and efficacy of epimacular brachytherapy (EMB) for chronic, active, neovascular age-related macular degeneration (nAMD).

METHODS

This pivotal, randomised, controlled surgical device trial recruited patients with chronic nAMD receiving intravitreal ranibizumab from 24 UK hospitals. Participants were randomised to either pars plana vitrectomy with 24 Gray EMB and pro re nata (PRN) ranibizumab (n=224) or PRN ranibizumab monotherapy (n=119). Although masking was not possible, masked clinicians assessed best-corrected visual acuity (BCVA) and imaging. After month 24, participants reverted to standard care, with either ranibizumab or aflibercept, returning for a month 36 study visit.

RESULTS

Of 363 participants, 309 (85.1%) completed month 36. The number of injections was 12.1±8.1 in the EMB group versus 11.4±6.1 in the ranibizumab group (difference 0.7, 95% CI of difference -0.9 to 2.3, p=0.41) between months 1 and 36, and 3.6±3.3 (n=200) versus 3.9±2.7 (n=102) (difference -0.3, 95% CI of difference -1.0 to 0.4, p=0.43) between months 25 and 36 (standard care). Over 36 months, BCVA change was -19.7±18.5 letters in the EMB group and -4.8±12.5 in the ranibizumab group (difference -14.9, 95% CI of difference -18.5 to -11.2, p<0.0001). The month 36 BCVA of 20 EMB-treated participants with microvascular abnormalities (MVAs) at month 24 was similar to EMB-treated participants without MVAs (-21.8 vs -19.4 letters, p=0.65).

CONCLUSION

EMB does not reduce the number of anti-vascular endothelial growth factor (VEGF) injections, either within or outside of a trial setting, and is associated with worse BCVA than anti-VEGF monotherapy.

TRIAL REGISTRATION NUMBER

NCT01006538.

Determining vitreous viscosity using fluorescence recovery after photobleaching

PURPOSE

Vitreous humor is a complex biofluid whose composition determines its structure and function. Vitreous viscosity will affect the delivery, distribution, and half-life of intraocular drugs, and key physiological molecules. The central pig vitreous is thought to closely match human vitreous viscosity. Diffusion is inversely related to viscosity, and diffusion is of fundamental importance for all biochemical reactions. Fluorescence Recovery After Photobleaching (FRAP) may provide a novel means of measuring intravitreal diffusion that could be applied to drugs and physiological macromolecules. It would also provide information about vitreous viscosity, which is relevant to drug elimination, and delivery.

METHODS

Vitreous viscosity and intravitreal macromolecular diffusion of fluorescently labelled macromolecules were investigated in porcine eyes using fluorescence recovery after photobleaching (FRAP). Fluorescein isothiocyanate conjugated (FITC) dextrans and ficolls of varying molecular weights (MWs), and FITC-bovine serum albumin (BSA) were employed using FRAP bleach areas of different diameters.

RESULTS

The mean (±standard deviation) viscosity of porcine vitreous using dextran, ficoll and BSA were 3.54 ± 1.40, 2.86 ± 1.13 and 4.54 ± 0.13 cP respectively, with an average of 3.65 ± 0.60 cP.

CONCLUSIONS

FRAP is a feasible and practical optical method to quantify the diffusion of macromolecules through vitreous.

Aqueous Humor Analyses in Patients with Diabetic Retinopathy Who Had Undergone Panretinal Photocoagulation

PURPOSE

To determine the associations between aqueous humor cytokine levels and the severity of diabetic retinopathy and the prior panretinal photocoagulation (PRP) status of patients with diabetic macular edema (DME).

METHODS

We divided 98 DME patients into those with nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), and PRP patients. We compared the concentrations of interleukin- (IL-) 1β, IL-6, IL-8, IL-10, and IL-17; placental growth factor (PlGF); and vascular endothelial growth factor (VEGF) in the aqueous humors. We subclassified PRP patients by the interval between PRP and aqueous sampling and analyzed the associations between aqueous cytokine levels and this interval.

RESULTS

The aqueous humor levels of IL-6, IL-8, VEGF, and PlGF were significantly higher in the PDR group than in the NPDR group. The PlGF and VEGF levels in the PDR group were significantly higher than those in the PRP group. On PRP subgroup analyses, patients who had undergone PRP within 6 months prior exhibited higher levels of VEGF, PlGF, and TNF-α than did those who had undergone PRP more than 12 months prior. The TNF-α level of the PRP subgroup treated within 6 months prior was significantly higher than that of the PDR group. Regression analyses showed that the levels of VEGF, PlGF, and TNF-α decreased significantly as the interval between PRP and aqueous sampling became longer.

CONCLUSIONS

PDR patients exhibited higher concentrations of VEGF and certain inflammatory cytokines than did NPDR and PRP patients. In the latter patients, the intraocular VEGF and inflammatory cytokine levels fell gradually over time.

The Impact of Interval between Recurrence and Reinjection in Anti-VEGF Therapy for Diabetic Macular Edema in Pro Re Nata Regimen

Background: Pro re nata (PRN) regimen using anti-vascular endothelial growth factor (VEGF) agent is popular for the treatment of diabetic macular edema (DME). We investigated the influence of waiting time (WT) and interval between the date of recurrence of edema and re-injection on treatment efficacy. Methods: This retrospective study conducted at 7 sites in Japan enrolled patients who received intravitreal injection of ranibizumab (IVR) and aflibercept (IVA) in 1+PRN regimen. Enrolled patients were divided into 2 groups: prompt group (less than 1 week) and deferred group (3 weeks or more). Central retinal thickness (CRT) and best corrected visual acuity (BCVA) were measured every month for 1 year. Results: CRT in the deferred group was significantly higher than that in the prompt group at 2, 5, 6, 7, and 12 months (p < 0.05). BCVA in the prompt group was significantly better than that in the deferred group at 7, 10, and 12 months (p < 0.05). Conclusion: The prompt group was superior in anatomical and functional improvement of DME in anti-VEGF therapy than the deferred group. Our data suggests that shorter WT is recommended for better visual prognosis in the treatment for DME.

Impact of silicone oil tamponade on intravitreally injected vancomycin pharmacokinetics in cynomolgus monkey eyes

Intravitreal injections of vancomycin (VCM) and ceftazidime (CAZ) are commonly used to treat infectious endophthalmitis. When patient cases require retinal detachment with silicone oil (SO) tamponade, the antibiotic doses are empirically reduced to 25 %. Currently, there is no scientific evidence for these empirical dose reductions. The purpose of the present study is to determine the quantitative impact that SO tamponades have on intraocular VCM pharmacokinetics. Because of high invasiveness of frequent sampling of intraocular VCM concentrations in human, this pharmacokinetic study was performed in cynomolgus monkey's eyes. Population pharmacokinetic modeling and simulation were performed using 75 different intraocular VCM concentrations obtained from 8 male cynomolgus monkeys. A one-compartment model with a first-order diffusion rate was used as a structural pharmacokinetic model. From the covariate analysis, SO tamponade significantly decreased the volume of distribution while pars plana vitrectomy with lensectomy (PPV) significantly increased the clearance and diffusion rate constants. From the Monte Carlo simulation (n = 1,000), the median time above minimum inhibitory concentration (T_>MIC, a therapeutic effect index) durations of SO and normal eyes at clinical doses of 1,000 µg were 2.6 and 11.0 days, respectively. Using intravitreal injections of VCM with SO tamponade or PPV may reduce the therapeutic effect.

B-SCAN ULTRASONOGRAPHY OF VITREOUS DYNAMICS DURING INTRAVITREAL ADMINISTRATION OF ANTIANGIOGENICS

PURPOSE

To study the distribution of angiogenesis inhibitors (anti-Vascular Endothelial Growth Factor) injected into the vitreous cavity by means of simultaneous ultrasonography.

METHODS

Three hundred and thirty-two B-scan ultrasound sequences of 121 eyes from 95 patients were recorded simultaneously to the intravitreal anti-Vascular Endothelial Growth Factor administration. The dynamics of the injected substance and the presence of reflux were studied, associating them with the presence/absence of total posterior vitreous detachment.

RESULTS

Three well-defined patterns were distinguished. Pattern A: the medication penetrates the vitreous in a linear manner until reaching the retina (3.6%, n = 12). Pattern B: the medication adopts a globular shape and then moves down reaching the retrohyaloid space (37%, n = 123). Pattern C: the medication remains in a globular form (54%, n = 180). The pattern was not identified in 17 (5.1%) injections. Pattern A was only observed in vitrectomized eyes. The reflux (7.8%) was exclusive in eyes showing a C pattern. A relationship (P < 0.001) was observed between the presence/absence of total posterior vitreous detachment, the patterns, and the presence of reflux.

CONCLUSION

This study document for the first time the behavior of antiangiogenic medication injected into the vitreous cavity and how its distribution and the presence of reflux is conditioned by the previous state of the vitreous body.

Comparison of Intravitreal Dexamethasone Implant and Ranibizumab in Vitrectomized Eyes with Diabetic Macular Edema

Purpose

This retrospective study aimed to compare the efficacy of intravitreal ranibizumab (IVR) and intravitreal dexamethasone implant (IDI) for pseudophakic vitrectomized eyes with diabetic macular edema (DME) in a single institution.

Methods

Pseudophakic vitrectomized eyes with treatment-naïve center-involved DME were enrolled, with one eye in each patient. They were divided into two groups: one group receiving IDI every 3 to 4 months and another group receiving IVR using 3 monthly plus treat-and-extend injections, all with monthly follow-up for 6 months. Switch of intravitreal drugs or deferred macular laser was not allowed. Primary outcome measures included change in central foveal thickness (CFT) in 1 mm by spectral-domain optical coherence tomography and best-corrected visual acuity (BCVA) at Month 6.

Results

Twenty-two eyes were included in the IDI group and 26 eyes in the IVR group. The baseline demographics, glycosylated hemoglobin level, intraocular pressure (IOP), BCVA, and CFT did not significantly differ (p > 0.05). Compared to baseline data, CFT decreased and BCVA improved significantly after either IDI or IVR at Month 6 (p < 0.05). Significantly better mean final BCVA (0.38 logMAR vs. 0.62 logMAR, p=0.04), more mean visual gain (−0.30 logMAR vs. −0.15 logMAR, p=0.02), lower mean final CFT (310.9 μm vs. 384.2 μm, p=0.04), and larger mean CFT decrease (−150.0 μm vs. −60.1 μm, p=0.03) were found in the IDI group compared to those in the IVR group. A smaller mean treatment number (2.6 vs. 5.6, p < 0.001) and higher rate of postinjection ocular hypertension requiring topical hypotensive agent therapy (27.3% vs. 0%, p=0.0002) were demonstrated in the IDI group than those in the IVR group.

Conclusion

We concluded that IDI and IVR can both effectively treat vitrectomized eyes with DME. Dexamethasone implants had significantly better visual/anatomical improvement, smaller treatment number, and higher rate of elevated IOP after injection than IVR in pseudophakic vitrectomized eyes with DME in a 6-month period.

Self-sealing hyaluronic acid-coated 30-gauge intravitreal injection needles for preventing vitreous and drug reflux through needle passage

Self-sealing hyaluronic acid (HA)-coated self-sealing 30-gauge needles exhibiting instant leakage prevention of intravitreal humor and injected drug were developed in this study. Ninety New Zealand rabbits were used in this study. We assessed dye regurgitation in intravitreal ICG dye injections using HA-coated needles (HA needle group) and conventional needles (control group). Vitreous humor levels of anti-vascular endothelial growth factor (VEGF) were compared between groups one, three, and seven days after intravitreal bevacizumab (0.016 mL) injections. Expression levels of inflammatory cytokines in the aqueous humor and vitreous humor, including prostaglandin E₂ (PGE₂), interferon-γ, tumor necrosis factor-α, interleukin (IL)-1β, IL-4, IL-6, IL-17, and IL-8, were compared between HA needle, control, and normal (in which intravitreal injection was not performed) groups following 12 intravitreal injections over a period of one week. In the HA needle group, HA remained at the injection site and blocked the hole after intravitreal injection. Dye regurgitation occurred significantly less frequently in the HA needle group (16.7%) than the control group (55.6%) after intravitreal ICG dye injection. Meanwhile, vitreous anti-VEGF levels were markedly higher in the HA needle group than the control group one and three days after intravitreal bevacizumab injections. After 12 intravitreal injections, expression levels of aqueous and vitreous IL-8 significantly increased in the control group compared to the HA needle and normal groups. Conversely, there were no significant differences in the expression of the other seven cytokines among the three groups. Intravitreal injections using HA-coated self-sealing 30-gauge needles can block the outflow of vitreous humor and drugs through the needle passage.

Pharmacokinetics of Intravitreal Vancomycin and Ceftazidime in Silicone Oil-Filled Macaque Eyes

Purpose

This study evaluated the pharmacokinetics of intravitreal vancomycin and ceftazidime in the aqueous humor of macaque eyes filled with silicone oil in the vitreous cavity.

Methods

Intravitreal vancomycin (1 mg/0.1 mL) and ceftazidime (2 mg/0.1 mL) were injected into four normal macaque eyes, four vitrectomized aphakic macaque eyes, and four previously vitrectomized aphakic macaque eyes filled with silicone oil (silicone oil-filled eyes). Aqueous humor samples (0.1 mL) were obtained just before injection and at 2 and 5 hours and 1, 2, 3, 5, 7, and 10 days after injection. In each group, corneal endothelial cell density (ECD) measurements and electroretinogram (ERG) recordings were obtained before injection and after 1 month.

Results

The half-lives of vancomycin in the aqueous humor of normal, vitrectomized, and silicone oil-filled eyes were 29.4, 21.1, and 6.8 hours, respectively, and those of ceftazidime were 20.4, 5.2, and 3.1 hours, respectively. The maximum vancomycin aqueous humor concentrations of normal, vitrectomized, and silicone oil-filled eyes were 151.4, 205.6, and 543.5 µg/mL, respectively, and the maximum ceftazidime aqueous humor concentrations are 64.6, 260.0, and 1176.3 µg/mL, respectively. There was no change in ECD, and ERG was not declined after intravitreal injection in all groups.

Conclusions

The half-lives of vancomycin and ceftazidime in the aqueous humor were shorter in silicone oil-filled eyes than in normal and vitrectomized eyes. High antibiotic concentrations in silicone oil-filled eyes seemed to be well tolerated.

Translational Relevance

This study aids in estimating how often an antibiotic should be intravitreally injected for endophthalmitis of silicone oil-filled eyes.

Efficacy of anti-vascular endothelial growth factor agents for treating neovascular age-related macular degeneration in vitrectomized eyes

PURPOSE

To evaluate the efficacy of intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents for treatment of neovascular age-related macular degeneration (nAMD) in vitrectomized eyes.

METHODS

The medical records were reviewed of nAMD patients treated with anti-VEGF agents who previously underwent pars plana vitrectomy (PPV). PPV was performed with complete posterior vitreous detachment induction.

RESULTS

A total of 44 eyes from 44 patients were included. The mean central foveal thickness (CFT) was 478.50 ± 156.93 μm at baseline, 414.25 ± 143.55 μm (86.6% of baseline) at 1 month after first injection (P < 0.001), and 386.75 ± 141.45 μm (80.8% of baseline) after monthly multiple injections (2.30 ± 1.07; range, 1-5) (P < 0.001). The mean logarithm of the minimum angle of resolution best-corrected visual acuity visual acuity (BCVA) was 0.85 ± 0.57 at baseline, 0.86 ± 0.63 after the first injection, and 0.84 ± 0.64 after monthly multiple injections. BCVA improved in 39.5% at 1 month after first injection and 45.2% at 1 month after monthly multiple injections. In the subgroup analysis, CFT of eyes with the posterior capsule decreased significantly to 85.8% and 79.8% of baseline values at 1 month after the first injection and after monthly multiple injections, respectively. CFT of eyes without the posterior capsule decreased to 91.6% and 87.4% of baseline values at 1 month after the first injection and after monthly multiple injections, respectively, without statistical significance.

CONCLUSION

Monthly injections of Intravitreal anti-VEGF agents induced favorable anatomical improvement and vision maintenance in vitrectomized eyes with nAMD.

One-Year Outcome of Aflibercept Intravitreal Injection in Vitrectomized Eyes with Diabetic Macular Edema

Aim

To evaluate the efficacy of intravitreal Aflibercept injection (IAI) for vitrectomized eyes with diabetic macular edema (DME) at one year.

Methods

This is a prospective, non-comparative, multicenter observational study including diabetic patients whose HbA1c is < 9%, with visual acuity between 20/400 to 20/40 due to DME, who have undergone vitrectomy since at least 3 months before the first aflibercept injection. Treatment protocol included 5 monthly aflibercept injection followed by a ProReNata regimen during the first year. Visual acuity, OCT findings and number of IAI were assessed at 6 months and one year.

Results

Forty-six eyes were included. Indications for vitrectomy were epiretinal membrane (58.7%), intravitreal hemorrhage (26.1%), and vitreomacular traction (8.7%), retinal detachment (4.3%), and other cause (4.3%). Median duration of macular edema was 3 years. Median interval between vitrectomy and first visit was 9 months. Thirty eyes were non-naïve and received previously thermal laser (44.3%), intravitreal injection of triamcinolone (26.7%), of ranibizumab (70%), of dexamethasone implant (36.7%), or bevacizumab (6.7%). Data was available for 35 eyes at 1 year. Visual gain was significant, +6 letters (p <0.001) and central subfield thickness (CST) decreased significantly (−108μm, p < 0.001) at 1 year. Mean number of injections was 9.3 and mean interval injection was 5.8 weeks.

Conclusion

These results suggest that IAI may be beneficial in vitrectomized eyes with refractory DME which require frequent injections to obtain visual and anatomical improvement.

Clinical Trial Registration

http://www.clinicaltrials.gov, registration Number NCT02874859.

Comparison of the intraocular pressure following an intravitreal triamcinolone acetonide injection for diabetic macula oedema in vitrectomised and non-vitrectomised eyes

Purpose

To compare the intraocular pressure (IOP) after an intravitreal triamcinolone acetonide (IVTA) between vitrectomised and non-vitrectomised eyes in patients with diabetes and diabetic macular oedema (DME).

Design

Retrospective comparative study

Methods

Medical records of 157 patients (157 eyes) with type 2 diabetes who received IVTA for DME were reviewed, and the best-corrected visual acuity, IOP and optical central retinal thickness (CRT) were compared preoperatively, at 1, 4, 12 and 24 weeks after IVTA between the vitrectomised and non-vitrectomised groups.

Results

IOP significantly increased at 1 (p<0.0001), 4 (p<0.0001), 8 (p<0.0001), 12 (p=0.0019), 16 (p=0.0006) and 20 weeks (p=0.0191) in the non-vitrectomised group, whereas a significant increase was only observed at 1 (p=0.0003) and 4 weeks (p=0.0006) in the vitrectomised group. ΔIOP, IOP changes from baseline, in the non-vitrectomised group was significantly higher than that in the vitrectomised group at 4 (p=0.0014), 8 (p=0.0081), 12 (p=0.0032) and 16 weeks (p=0.0038). No significant difference was observed in logMAR and CRT at any time point after IVTA between the two groups.

Conclusions

After an initial IVTA, increased IOP and ΔIOP from the baseline IOP were significantly more frequently observed in the non-vitrectomised than that in the vitrectomised group. IVTA is a safer and more effective treatment option for DME in vitrectomised than that in non-vitrectomised eyes.

Evaluation of Month-24 Efficacy and Safety of Epimacular Brachytherapy for Previously Treated Neovascular Age-Related Macular Degeneration: The MERLOT Randomized Clinical Trial

Importance

Although anti-vascular endothelial growth factor (VEGF) treatment offers better outcomes than the natural history of neovascular age-related macular degeneration (ARMD), a less burdensome, less expensive, and more durable treatment is needed.

Objective

To assess the efficacy and safety of epimacular brachytherapy (EMB) for chronic, active, neovascular ARMD.

Design, Setting, and Participants

The Macular Epiretinal Brachytherapy vs Ranibizumab (Lucentis) Only Treatment (MERLOT) pivotal device trial was conducted at 24 National Health Service hospitals across the UK. Patients who had neovascular ARMD and received intravitreal ranibizumab were enrolled between November 10, 2009, and January 30, 2012. Eligible patients were randomized 2:1 and were stratified by lens status and angiographic lesion type to receive either EMB plus as-needed ranibizumab or as-needed ranibizumab monotherapy. Participants were followed up monthly for 24 months and then assessed at a final visit at month 36. Masking of participants and clinicians was not possible, but best-corrected visual acuity (BCVA) and imaging were analyzed by masked assessors. Analysis followed the intent-to-treat approach.

Interventions

Pars plana vitrectomy with 24 Gy EMB plus as-needed ranibizumab vs as-needed ranibizumab monotherapy.

Main Outcomes and Measures

Coprimary outcomes were the number of as-needed ranibizumab injections and the mean change in Early Treatment Diabetic Retinopathy Study (ETDRS) BCVA with a noninferiority margin of -5 ETDRS letters. Secondary outcomes were the percentage of participants losing fewer than 15 ETDRS letters and gaining 0 or more or 15 or more ETDRS letters and the mean change in angiographic total lesion size, choroidal neovascularization size, and foveal thickness on optical coherence tomography.

Results

Of 363 participants, 329 (90.6%) completed 24 months of follow-up (222 participants in the EMB group and 107 in the ranibizumab group). The mean (SD) age of the combined groups was 76.5 (7.4) years. The mean (SD) number of ranibizumab injections was 9.3 (6.7) in the EMB group and 8.3 (4.5) in the ranibizumab group, with a difference of 1.0 injection (95% CI, -0.3 to 2.3; P = .13). The mean (SD) BCVA change was -11.2 (15.7) ETDRS letters in the EMB group and -1.4 (10.9) ETDRS letters in the ranibizumab group, with a difference of 9.8 ETDRS letters (95% CI, -6.7 to -12.9). In the EMB group, 65.6% of participants (160 of 244) lost fewer than 15 ETDRS letters vs 86.6% (103 of 119) in the ranibizumab group, with a difference of 21% (95% CI, 12.4%-29.5%; P < .001). Microvascular abnormalities occurred in 20 of 207 eyes (9.7%) in the EMB group and 1 of 97 eyes (1.0%) in the ranibizumab group. These abnormalities occurred outside the foveal center, and there were no unexpected safety concerns.

Conclusions and Relevance

The MERLOT trial found that despite the acceptable safety of EMB, it did not reduce the number of ranibizumab injections and was associated with worse visual acuity than anti-VEGF treatment alone; these results do not support EMB use as an adjunct treatment for chronic, active neovascular ARMD.

Trial Registration

ClinicalTrials.gov Identifier: NCT01006538.

Effect of dexamethasone intravitreal implant in vitrectomized and nonvitrectomized eyes of Taiwanese patients with treatment-naïve diabetic macular edema

BACKGROUND/PURPOSE

Vitrectomy may affect intravitreal drug clearance and efficacy for treating diabetic macular edema (DME). This study aimed to evaluate functional and anatomical outcomes of intravitreal dexamethasone (DEX) implant for vitrectomized and nonvitrectomized eyes with treatment-naïve DME in Taiwanese patients.

METHODS

In this retrospective single-center study, we reviewed treatment-naïve patients who received DEX implant monotherapy for center-involved DME from January 2015 to May 2017. Retreatments were provided at least 4 months apart as needed. The primary outcomes included changes from baseline in best-corrected visual acuity (BCVA) and central foveal thickness (CFT) at Month 6. Adverse events were recorded.

RESULTS

Twenty-seven eyes in 27 patients had prior vitrectomy and 43 eyes in 41 patients without vitrectomy. Baseline data were comparable. Overall, the improvements in BCVA and CFT were significant by 1 month post-treatment and sustained throughout the study (all p < 0.05). At Month 6, BCVA improved by 16.5 and 12.1 letters, and CFT reduced by 138.0 and 121.9 μm in vitrectomized and nonvitrectomized eyes, respectively, with a mean of 1.5 DEX implant injection. No significant differences in clinical outcomes were seen between the two groups (all p > 0.05). DEX implant injection was well tolerated. About 30% of patients had post-injection intraocular pressure value > 20 mmHg, and all were manageable with topical hypotensive agents, and no serious ocular complication was observed.

CONCLUSION

In this 6-month retrospective study, intravitreal DEX implant was effective in Taiwanese patients with treatment-naïve DME regardless of vitrectomy status.

Drug Delivery to the Posterior Segment of the Eye: Biopharmaceutic and Pharmacokinetic Considerations

The treatment of the posterior-segment ocular diseases, such as age-related eye diseases (AMD) or diabetic retinopathy (DR), present a challenge for ophthalmologists due to the complex anatomy and physiology of the eye. This specialized organ is composed of various static and dynamic barriers that restrict drug delivery into the target site of action. Despite numerous efforts, effective intraocular drug delivery remains unresolved and, therefore, it is highly desirable to improve the current treatments of diseases affecting the posterior cavity. This review article gives an overview of pharmacokinetic and biopharmaceutics aspects for the most commonly-used ocular administration routes (intravitreal, topical, systemic, and periocular), including information of the absorption, distribution, and elimination, as well as the benefits and limitations of each one. This article also encompasses different conventional and novel drug delivery systems designed and developed to improve drug pharmacokinetics intended for the posterior ocular segment treatment.

Ocular Half-Life of Intravitreal Biologics in Humans and Other Species: Meta-Analysis and Model-Based Prediction

Therapeutic antibodies administered intravitreally are the current standard of care to treat retinal diseases. The ocular half-life (t_1/2) is a key determinant of the duration of target suppression. To support the development of novel, longer-acting drugs, a reliable determination of t_1/2 is needed together with an improved understanding of the factors that influence it. A model-based meta-analysis was conducted in humans and nonclinical species (rat, rabbit, monkey, and pig) to determine consensus values for the ocular t_1/2 of IgG antibodies and Fab fragments. Results from multiple literature and in-house pharmacokinetic studies are presented within a mechanistic framework that assumes diffusion-controlled drug elimination from the vitreous. Our analysis shows, both theoretically and experimentally, that the ocular t_1/2 increases in direct proportion to the product of the hydrodynamic radius of the macromolecule (3.0 nm for Fab and 5.0 nm for IgG) and the square of the radius of the vitreous globe, which varies approximately 24-fold from the rat to the human. Interspecies differences in the proportionality factors are observed and discussed in mechanistic terms. In addition, mathematical formulae are presented that allow prediction of the ocular t_1/2 for molecules of interest. The utility of these formulae is successfully demonstrated in case studies of aflibercept, brolucizumab, and PEGylated Fabs, where the predicted ocular t_1/2 values are found to be in reasonable agreement with the experimental data available for these molecules.

Effectiveness of Intravitreal Dexamethasone Implant Treatment for Diabetic Macular Edema in Vitrectomized Eyes

Objectives:

To report the effectiveness and long-term outcomes of intravitreal dexamethasone implantation for diabetic macular edema (DME) in vitrectomized eyes

Materials and Methods:

Medical records of patients were retrospectively reviewed. Time of pars plana vitrectomy (PPV), PPV indications, interval between DEX injection and PPV, other intravitreal treatment prior to DEX application, best corrected visual acuity (BCVA), intraocular pressure (IOP), and central retinal thickness (CRT) measured by optical coherence tomography were recorded.

Results:

Seventeen eyes of 17 patients were included in the study. The mean follow-up after DEX injection was 21±2.4 months (12-43 months). The female/male ratio was 11/6. Mean age was 60.7 years (46-70 years). Sixteen eyes (94.1%) were pseudophakic at the time of DEX treatment. The most common indication for PPV was tractional retinal detachment (8 eyes, 47.1%). Ten eyes (58.8%) received a single injection and a total of 30 DEX implantations were performed. Mean BCVA was 0.77 logarithm of the minimum angle of resolution (logMAR) units before the first injection and improved to 0.64, 0.68 and 0.66 logMAR after 1, 3 and 6 months, respectively (p<0.01). CRT decreased significantly from 452 µm at baseline to 310, 368±34 and 375 µm after 1, 3 and 6 months, respectively (p<0.04). Mean IOP was 16±1.2 mmHg at baseline and 18.2, 18.8 and 18.5 mmHg after 1, 3, and 6 months (p>0.05). Two eyes (%8) received topical anti-glaucoma medication (IOP≥25 mmHg). Similar results were observed in eyes receiving repeated DEX injections.

Conclusion:

Intravitreal DEX injection treatment seems to be effective for improving BCVA and decreasing CRT in vitrectomized eyes with DME. This effect seemed to last for 6 months in most eyes, but maximized at 3 months. Patients with repeated injections often require injection before 6 months.

Change of Vascular Endothelial Growth Factor Levels following Vitrectomy in Eyes with Proliferative Diabetic Retinopathy

Purpose

To study the change of concentrations of vascular endothelial growth factor (VEGF) in vitreous cavity after vitrectomy in eyes with proliferative diabetic retinopathy (PDR).

Methods

In this retrospective study, intravitreal fluid samples were taken at baseline (beginning of the vitrectomy) and postoperatively (several days later after vitrectomy) at the time of prophylactic injection of bevacizumab in forty-eight eyes of forty-eight patients with PDR. Postvitrectomy fluid samples were divided into four groups according to the time interval between the vitrectomy and the injection (group 1, 3–5 days; group 2, 6–10 days; group 3, 11–15 days; group 4, 16–21 days; twelve eyes in each group). Postvitrectomy fluid sample was paired with baseline sample for each eye. VEGF concentrations in the samples were determined by enzyme-linked immunosorbent assay. Recurrent vitreous hemorrhage and neovascular glaucoma within six months postvitrectomy were also analyzed.

Results

Overall, the intravitreal VEGF level after vitrectomy (median, 36.95 pg/ml; range, 3.2–1,299.4 pg/ml) was significantly less than the VEGF level at baseline (median, 704.5 pg/ml; range, 30.6–1,981.1 pg/ml). Postoperative and baseline VEGF levels were significantly correlated (r = 0.499, p < 0.01). Both the absolute value of postoperative VEGF concentrations and the postop/baseline VEGF ratios declined with time and dramatically decreased in groups 3 and 4. In only two eyes, the postoperative VEGF level was even higher than the baseline VEGF level (postop/baseline VEGF ratio >1), and recurrent vitreous hemorrhage developed within six months in these two eyes.

Conclusions

After vitrectomy for PDR, intravitreal VEGF levels decreased substantially in the majority of patients, while persistent high-VEGF level occurred in a few individuals. Postoperative VEGF levels and postop/baseline VEGF ratio declined with time. The postop/preop VEGF ratio may serve as a predictor for late complications.

Intravitreal anti-VEGF drug delivery systems for age-related macular degeneration

Age-related macular degeneration is the most common cause of vision loss in elderly people in developed countries. Nowadays, in clinical practice, three anti-VEGF drugs are commonly used (bevacizumab, aflibercept and ranibizumab), requiring repeated intravitreal injections. In order to minimise the number of injections, research on intravitreal drug delivery systems (DDSs) is needed. In this review, the DDSs developed up to date regarding intravitreal anti-VEGF drugs have been summarised, which include systems as hydrogels, liposomes, microparticles, nanoparticles or implants. Most of the studies have focused on the extended in vitro release behaviour of the developed DDSs, but data as antibody bioactivity, biocompatibility or in vivo stability is sometimes scarce. Moreover, as DDS development relies on in vivo pharmacokinetic analyses to evaluate the extended drug release, all the information regarding anti-VEGF intravitreal pharmacokinetics in different animal species have been compiled.

Hydrodynamics of Intravitreal Injections into Liquid Vitreous Substitutes

Intravitreal injections have become the cornerstone of retinal care and one of the most commonly performed procedures across all medical specialties. The impact of hydrodynamic forces of intravitreal solutions when injected into vitreous or vitreous substitutes has not been well described. While computational models do exist, they tend to underestimate the starting surface area of an injected bolus of a drug. Here, we report the dispersion profile of a dye bolus (50 µL) injected into different vitreous substitutes of varying viscosities, surface tensions, and volumetric densities. A novel 3D printed in vitro model of the vitreous cavity of the eye was designed to visualize the dispersion profile of solutions when injected into the following vitreous substitutes—balanced salt solution (BSS), sodium hyaluronate (HA), and silicone oils (SO)—using a 30G needle with a Reynolds number (Re) for injection ranging from approximately 189 to 677. Larger bolus surface areas were associated with faster injection speeds, lower viscosity of vitreous substitutes, and smaller difference in interfacial surface tensions. Boluses exhibited buoyancy when injected into standard S1000. The hydrodynamic properties of liquid vitreous substitutes influence the initial injected bolus dispersion profile and should be taken into account when simulating drug dispersion following intravitreal injection at a preclinical stage of development, to better inform formulations and performance.

Pharmacokinetics of Intravitreal Anti-VEGF Drugs in Age-Related Macular Degeneration

Intravitreal administration of anti-vascular endothelial growth factor (VEGF) antibodies has become the standard treatment for Age-Related Macular Degeneration; however, the knowledge of their pharmacokinetics is limited. A comprehensive review of the preclinical and clinical pharmacokinetic data that were obtained in different studies with intravitreal bevacizumab, ranibizumab, and aflibercept has been conducted. Moreover, the factors that can influence the vitreous pharmacokinetics of these drugs, as well as the methods that were used in the studies for analytical determination, have been exposed. These anti-VEGF drugs present different charge and molecular weights, which play an important role in vitreous distribution and elimination. The pharmacokinetic parameters that were collected differ depending on the species that were involved in the studies and on physiological and pathological conditions, such as vitrectomy and lensectomy. Knowledge of the intravitreal pharmacokinetics of the anti-VEGF drugs that were used in clinical practice is of vital importance.

Outcomes of vitrectomy combined with subretinal tissue plasminogen activator injection for submacular hemorrhage associated with polypoidal choroidal vasculopathy

PURPOSE

To examine the outcomes of vitrectomy with subretinal tissue plasminogen activator (tPA) injection and postoperative intravitreal antivascular endothelial growth factor (VEGF) injection for submacular hemorrhage (SMH) associated with polypoidal choroidal vasculopathy (PCV).

STUDY DESIGN

Retrospective, consecutive case series.

METHODS

Patients who underwent vitrectomy for SMH associated with PCV and who were followed up for at least 12 months were included. Surgery consisted of vitrectomy with subretinal tPA and air tamponade. Postoperative intravitreal anti-VEGF was administered pro re nata. The following were examined: best-corrected visual acuity (BCVA) at baseline, at 1 month, and at the final visit; the percentage of patients requiring anti-VEGF postoperatively; and the number of injections administered.

RESULTS

This study included 23 eyes of 23 patients (21 men, 2 women) with a mean age of 72.5 ± 9.0 years. The mean duration from disease onset to surgery was 9.0 ± 6.6 days. The mean maximum SMH size was 5.8 ± 4.8 disc diameters. The mean follow-up period was 33 ± 14 months. The BCVA was significantly improved when compared with baseline 1 month after surgery and at the final visit. Postoperative anti-VEGF was required for 91% of the eyes. In eyes that underwent anti-VEGF therapy until the final visit, the mean injection number was 4.1/year.

CONCLUSIONS

Vitrectomy with subretinal tPA and air tamponade improved visual acuity in patients with SMH associated with PCV. Postoperative intravitreal anti-VEGF injection maintained the improved BCVA throughout a mean period of 33 months.

Novel Triamcinolone Acetonide-Loaded Liposomes Topical Formulation for the Treatment of Cystoid Macular Edema After Cataract Surgery: A Pilot Study

Purpose: To report tolerability, safety, and efficacy of a topical triamcinolone acetonide-loaded liposomes formulation (TA-LF) in targeting the macular area in patients with refractory pseudophakic cystoid macular edema (PCME).

Methods: For tolerability, safety and efficacy evaluation, 12 eyes of 12 patients with refractory PCME were exposed to one drop of TA-LF (TA at 0.2%) every 2 h for 90 days or until best-corrected visual acuity (BCVA) was achieved. Intraocular pressure (IOP), slit lamp examination, and central foveal thickness (CFT) were analyzed at every visit.

Results: Patients with refractory PCME under TA-LF therapy showed a significant improvement in BVCA and CFT without significant IOP modification (P = 0.94). On average CFT decreased to 206.75 ± 135.72 μm and BCVA improved to 20.08 ± 10.35 letters (P < 0.0005). BCVA was achieved at 10.58 ± 6.70 weeks (range 2–18). TA-LF was well tolerated in all cases. Neither ocular surface abnormalities nor adverse events were recorded.

Conclusion: TA-LF was well tolerated and improved BCVA and CFT on patients with refractory PCME.

Iluvien™ (Fluocinolone Acetonide 0.19 mg Intravitreal Implant) in the Treatment of Diabetic Macular Edema: A Review

Diabetic macular edema (DMO) is a leading cause of blindness in the working age population. Although anti-vascular endothelial growth factor (VEGF) therapy provided a major advance in treatment of DMO for many patients, there is a significant proportion of patients who maintain persistent DMO and have minimal response to anti-VEGF treatment. Iluvien (fluocinolone acetonide 0.19 mg [FAc]) is an important additional treatment option for DMO. In this review we describe the clinical context and the evidence for the use of the FAc implant in treating DMO, from pilot to randomized controlled studies, to later phase real world data. These studies indicate that the FAc implant is effective, well tolerated and a cost-effective option in the treatment of insufficiently responsive DMO.

Effects of kallidinogenase in patients undergoing vitrectomy for diabetic macular edema

PURPOSE

To evaluate the effectiveness of the combination of vitrectomy with kallidinogenase for diabetic macular edema (DME).

METHODS

This study was designed as a prospective, randomized, multicenter study comparing 19 eyes of 19 patients who received 150 units of kallidinogenase administered a day for 52 weeks from the day after vitrectomy (study group) with 20 eyes of 20 patients who received no kallidinogenase (control group). The main outcome measurements included logMAR visual acuity and central foveal thickness (CFT) before surgery and at 3, 6, 9, and 12 months after vitrectomy.

RESULTS

During follow-up, 11 patients dropped out (six in the study group and five in the control group), leaving 28 eyes in 28 patients for analysis (13 in the study group and 15 in the control group). Visual acuity improved significantly at 12 months in both groups compared with before surgery. The degree of improvement did not differ significantly between the groups. At 12 months, the mean CFT decreased significantly in both groups, with no significant difference in the rate of change between the two groups. In the study group, the visual acuity and CFT significantly improved from 3 to 12 months and from 6 to 12 months, whereas these parameters did not continue to improve in the control group after 6 months (for visual acuity) or 3 months (for CFT).

CONCLUSION

After vitrectomy for DME, visual acuity and CFT improved significantly in both groups, but only patients treated with kallidinogenase continued to have significant improvement throughout the study period.

Cost Evaluation of Early Vitrectomy versus Panretinal Photocoagulation and Intravitreal Ranibizumab for Proliferative Diabetic Retinopathy

PURPOSE

To evaluate costs and cost-utility of early vitrectomy (pars plana vitrectomy [PPV]) compared with panretinal photocoagulation (PRP) and intravitreal ranibizumab (IVR) for proliferative diabetic retinopathy (PDR) without diabetic macular edema.

DESIGN

A decision analysis model of cost-utility.

PARTICIPANTS

There were no participants.

METHODS

A decision analysis was based on results from the Diabetic Retinopathy Clinical Research Network Protocol S comparing treatment of PRP with IVR (0.3 mg) in PDR without incident macular edema to model the total 2-year costs and outcomes for each treatment scenario. These values were compared with the 2-year hypothetical costs of early PPV for PDR. Centers for Medicare and Medicaid Services data were used to calculate associated modeled costs in a hospital/facility-based and nonfacility setting. Cost-utility was calculated on the basis of the preserved visual utility and estimated life years remaining. In addition, costs for lifetime treatment were modeled for all scenarios and used to calculate lifetime quality-adjusted life years (QALY) costs for each scenario. Sensitivity analyses were performed to evaluate the impact of the model's assumptions.

MAIN OUTCOME MEASURES

Cost of treatment, utility, and cost per QALY.

RESULTS

The modeled cost per QALY of treatment for PDR for 2 years of utility in the facility (nonfacility) setting was $163 988 ($102 559) in the PRP group, $436 992 ($326 424) in the IVR group, and $181 144 ($107 965) in the PPV group. Sensitivity analysis showed that both IVR and PPV groups would have equivalent costs per QALY over the first 2 years if 78% (facility) and 80% (nonfacility) of patients in the PPV group required additional treatment with IVR (at the dose of 10.1 injections as in Protocol S). Beyond 2 years, the cost per QALY in the facility (nonfacility) setting was calculated as $61 695 ($21 752) in the PRP group, $338 348 ($239 741) in the IVR group, and $63 942 ($22 261) in the PPV group.

CONCLUSIONS

Early PPV as a strategy for treatment of PDR without macular edema demonstrates cost-utility similar to management with PRP and more favorable cost-utility compared with IVR in the short term. This advantage over IVR continues when lifetime costs are factored.

Retinal sensitivity after displacement of submacular hemorrhage due to polypoidal choroidal vasculopathy: effectiveness and safety of subretinal tissue plasminogen activator

PURPOSE

To investigate the effectiveness of displacement of submacular hemorrhage (SMH) caused by polypoidal choroidal vasculopathy (PCV) by assessing retinal sensitivity using microperimetry.

METHODS

We retrospectively reviewed the medical records of 11 consecutive PCV patients with SMH. All patients underwent vitrectomy, subretinal injection of tissue plasminogen activator, and fluid-air exchange, followed by antivascular endothelial growth factor therapy using a pro re nata regimen. The retinal sensitivity was measured by use of microperimetry before and after surgery.

RESULTS

The mean (SD) age of the patients was 74.1 ± 9.4 years. The mean SMH diameter was 6.8 ± 5.2 disc diameters. The best-corrected visual acuity (BCVA), mean retinal sensitivity, and mean number of measure points with a sensitivity ≥10 dB before the surgery were 0.94 ± 0.49, 4.2 ± 4.5 dB, and 15.6 ± 15.1 points, respectively. These had significantly improved 6 months after surgery (0.39 ± 0.37, 15.6 ± 7.3 dB, and 50.9 ± 22.2 points, respectively; P < 0.05 for all outcome measures). The mean number of measure points with an absolute scotoma before surgery had decreased significantly 6 months after surgery (from 40.5 ± 15.0 to 9.4 ± 16.0 points; P < 0.001).

CONCLUSIONS

Displacement of SMH effectively improves retinal sensitivity as well as BCVA.

Intravitreal Aflibercept for Patients With Diabetic Macular Edema Refractory to Bevacizumab or Ranibizumab: Analysis of Response to Aflibercept

PURPOSE

To investigate the short-term efficacy and safety of intravitreal aflibercept in a case series of patients with diabetic macular edema (DME) refractory to ranibizumab or bevacizumab.

DESIGN

A retrospective chart review.

METHODS

From September 2013 to March 2016, we identified patients with DME who developed resistance to bevacizumab or ranibizumab. Three monthly intravitreal aflibercept injections were administered in refractory cases. Nonresponse to aflibercept was defined as a paradoxical increase in central foveal thickness (CFT) and gain in best-corrected visual acuity (BCVA) of less than 1 line at 1 month after treatment compared with before aflibercept administration.

RESULTS

Out of a total of 72 eyes in 72 refractory patients, 42 eyes (58.3%) responded to aflibercept injections. The BCVA and CFT were 0.65 ± 0.32 logMAR and 438.5 ± 80.1 μm, respectively, before aflibercept treatment and significantly improved to 0.31 ± 0.17 logMAR (P = 0.0008) and 297.9 ± 19.1 μm (P = 0.0004), respectively, 1 month after 3 aflibercept injections in responders. No differences in baseline characteristics, including age, sex, glycosylated hemoglobin, serum creatinine, total cholesterol, lens status, grades of diabetic retinopathy, and CFT/BCVA before aflibercept management (P > 0.05), were observed between responders and nonresponders. There were 17 vitrectomized eyes in 30 nonresponders (56.7%), a significantly higher rate than among the 42 responders (0%; P = 0.00001).

CONCLUSIONS

Three monthly intravitreal aflibercept injections had benefit in nearly two thirds of cases with DME resistant to bevacizumab or ranibizumab over short-term follow-up. Vitrectomized eyes responded poorly to aflibercept treatment.

RECALCITRANT CYSTOID MACULAR EDEMA AFTER PARS PLANA VITRECTOMY

PURPOSE

To evaluate the outcomes of different types of treatment of chronic cystoid macular edema (CME) after pars plana vitrectomy.

METHODS

Retrospective review of eyes that developed chronic CME after pars plana vitrectomy treated with intravitreal triamcinolone acetonide (TCA) with or without the addition of anti-vascular endothelial growth factor.

RESULTS

Thirty-nine eyes of 37 patients were included, with a median duration between pars plana vitrectomy and onset of CME of 5 months (interquartile range, 3-12). In most eyes (66.7%), the main indication for surgery was for vitreomacular interface disorders, such as epiretinal membrane, vitreomacular traction, and macular hole. With intravitreal TCA, there was a significant decrease in central foveal thickness at 3, 6, and 12 months, compared with baseline (P = 0.0171, 0.0401, and 0.0024, respectively). A significant gain in vision was noted at 1 month compared with baseline (P = 0.0169), but this was not sustained at 3, 6, and 12 months (P = 0.4862, 0.9098, and 0.4312, respectively). The addition of bevacizumab to TCA did not provide any additional benefit for central foveal thickness and visual acuity. Thirty-two eyes (82.1%) were started on prophylactic antiglaucoma drops 2 weeks after a TCA injection, and no eye needed laser or surgery to control intraocular pressure.

CONCLUSION

Chronic CME after pars plana vitrectomy is recurrent and difficult to treat. Intravitreal TCA is effective in reducing CME, but there was only short-term visual acuity improvement even with continued reduction of central foveal thickness. Intraocular pressure did not significantly rise with the use of prophylactic antiglaucoma drops even with repeated injections.

Twelve-Month Follow-Up of Dexamethasone Implants for Macular Edema from Various Diseases in Vitrectomized and Nonvitrectomized Eyes

Purpose. To evaluate the best-corrected visual acuity (BCVA), central retinal thickness (CRT), and the number of dexamethasone implants needed to treat cystoid macular edema (CME) from various etiologies over 12 months in vitrectomized and nonvitrectomized eyes. Methods. This multicenter retrospective cohort study included 112 patients with CME secondary to retinal diseases treated pro re nata (PRN) with a 0.7 mg intravitreal dexamethasone implant for 12 months. The BCVA, CRT, adverse events, safety data, and number of implants were recorded. Results. Vitrectomized and nonvitrectomized eyes received means of three implants and one implant, respectively, over 12 months (P < 0.001). The mean BCVA of all patients improved from 0.13 at baseline to 0.33 (P < 0.001) 12 months after one (P = 0.001), two (P = 0.041), and three (P < 0.001) implants but not four implants (P = 0.068). The mean baseline CRT decreased significantly (P < 0.001) from 463 to 254 microns after 12 months with one (P < 0.001), two (P = 0.002), and three (P = 0.001) implants but not with four implants (P = 0.114). The anatomic and functional outcomes were not significantly different between vitrectomized and nonvitrectomized eyes. Increased IOP was the most common adverse event (23.2%). Conclusions. Dexamethasone implant administered PRN improved VA and decreased CRT in CME, with possible long-term clinically relevant benefits for treating CME from various etiologies. Vitrectomized eyes needed more implants compared with nonvitrectomized eyes.

Diabetic macular oedema: pathophysiology, management challenges and treatment resistance

Diabetic macular oedema (DMO) is the leading cause of vision loss in patients living with diabetes. DMO results from hyperglycaemia-induced activation of pathways that lead to oxidative stress and release of cytokines, impairing the inner and outer blood-retinal barriers. Improved understanding of the pathophysiological mechanisms leading to DMO have led to the development of effective therapies, including vitreoretinal surgery, laser photocoagulation, intravitreal anti-vascular endothelial growth factor drugs and corticosteroids. Advances in imaging, including fluorescein angiography and optical coherence tomography, have also enhanced diagnosis and management of the condition. Despite these advances, there remain patients who do not respond completely to therapy, reflecting the complex pathophysiology of DMO. These patients may be considered treatment-resistant. In this review, we summarise the pathophysiology of DMO, as well as the available treatments and their mechanism of action. Additionally, we focus on treatment-resistant disease and review the literature on potential options for managing this complication of diabetes.

Comparison of the Effectiveness of Intravitreal Ranibizumab for Diabetic Macular Edema in Vitrectomized and Nonvitrectomized Eyes

PURPOSE

To compare the effectiveness of intravitreal ranibizumab (IVR) for diabetic macular edema (DME) between eyes with and without previous vitrectomy.

PROCEDURES

We prospectively assessed the best-corrected visual acuity (BCVA) and central macular thickness (CMT) after IVR for 6 months.

RESULTS

There were no significant differences in the baseline BCVA and CMT between both groups. In the nonvitrectomized group (n = 15), the mean changes of BCVA and CMT from baseline to month 6 were significant (p < 0.01). In the vitrectomized group (n = 10), the improvement appeared to be slower, and the mean BCVA improvement was not significant (p = 0.5), although the mean CMT decrease was significant (p < 0.05). There were no significant differences in the mean changes of BCVA and CMT between both groups at 6 months.

CONCLUSIONS

The difference in the effectiveness of IVR between both groups was not significant. IVR can be a treatment option even for vitrectomized DME eyes.

Epimacular Brachytherapy for Previously Treated Neovascular Age-Related Macular Degeneration (MERLOT): A Phase 3 Randomized Controlled Trial

PURPOSE

To assess the safety and efficacy of epimacular brachytherapy (EMB) for patients with chronic, active, neovascular age-related macular degeneration (AMD).

DESIGN

Phase 3 randomized controlled trial.

PARTICIPANTS

Patients (n = 363) with neovascular AMD already receiving intravitreal ranibizumab injections.

INTERVENTION

Either pars plana vitrectomy with 24-gray EMB and ongoing pro re nata (PRN) ranibizumab (n = 224) or ongoing PRN ranibizumab monotherapy (n = 119).

MAIN OUTCOME MEASURES

The coprimary outcomes, at 12 months, were the number of PRN ranibizumab injections and Early Treatment of Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (VA). Secondary outcomes included the proportion of participants losing fewer than 15 ETDRS letters, angiographic total lesion size, choroidal neovascularization (CNV) size, and optical coherence tomography (OCT) foveal thickness. A predefined subgroup analysis tested the influence of baseline ocular characteristics on the response to EMB.

RESULTS

The mean number of PRN ranibizumab injections was 4.8 in the EMB arm and 4.1 in the ranibizumab monotherapy arm (P = 0.068). The mean VA change was -4.8 letters in the EMB arm and -0.9 letters in the ranibizumab arm (95% confidence interval of difference between groups, -6.6 to -1.8 letters). The proportion of participants losing fewer than 15 letters was 84% in the EMB arm and 92% in the ranibizumab arm (P = 0.007). In the EMB arm, the mean total lesion size increased by 1.2 mm(2) versus 0.4 mm(2) in the ranibizumab arm (P = 0.27). The CNV size decreased by 0.5 mm(2) in the EMB arm and by 1.3 mm(2) in the ranibizumab arm (P = 0.27). The OCT foveal thickness decreased by 1.0 μm in the EMB arm and by 15.7 μm in the ranibizumab arm (P = 0.43). Most subgroups favored ranibizumab monotherapy, some significantly so. One participant showed retinal vascular abnormality attributed to radiation, but otherwise safety was acceptable.

CONCLUSIONS

These results do not support the use of EMB for chronic, active, neovascular AMD. Safety is acceptable out to 12 months, but radiation retinopathy can occur later, so further follow-up is planned.

Pars plana vitrectomy combined with internal limiting membrane peeling for recurrent macular edema due to branch retinal vein occlusion after antivascular endothelial growth factor treatments

PURPOSE

To evaluate the anatomic and functional outcomes of pars plana vitrectomy combined with internal limiting membrane peeling for recurrent macular edema (ME) due to branch retinal vein occlusion (BRVO) after intravitreal injections of antivascular endothelial growth factor (anti-VEGF) agents.

METHODS

Twenty-four eyes of 24 patients with treatment-naive ME from BRVO were treated with intravitreal injections of anti-VEGF agents. Recurred ME was treated with pars plana vitrectomy combined with internal limiting membrane peeling.

RESULTS

After the surgery, ME was significantly reduced at 1 month (P=0.031) and the reduction increased with time (P=0.007 at the final visit). With the reduction in ME, treated eyes showed a slow improvement in visual acuity (VA). At the final visit, improvement in VA was statistically significant compared with baseline (P=0.048). The initial presence of cystoid spaces, serous retinal detachment, or subretinal hemorrhage under the fovea, as well as retinal perfusion status, showed no association with VA improvement. However, the presence of epiretinal membrane showed a significant association with the visual recovery. Although eyes without epiretinal membrane showed visual improvement (-0.10±0.32 in logarithm of the minimum angle of resolution [logMAR]), eyes with epiretinal membrane showed greater visual improvement (-0.38±0.12 in logMAR, P=0.012).

CONCLUSION

For recurrent ME due to BRVO after anti-VEGF treatment, particularly when accompanied by epiretinal membrane, pars plana vitrectomy combined with internal limiting membrane peeling might be a possible treatment option.