Effect of intravitreal bevacizumab on retrobulbar blood flow in injected and uninjected fellow eyes of patients with neovascular age-related macular degeneration

Retinal oxygen saturation, vessel diameter and flicker response in eyes with specific subtypes of neovascular age-related macular degeneration during aflibercept treatment

Purpose

To evaluate the effect of intravitreal aflibercept monotherapy on arterial and venous oxygen saturation, retinal vessel diameter and flicker response in patients with newly diagnosed specific subtypes of exudative maculopathy.

Methods

This prospective study included forty-four eyes of 44 patients with treatment-naïve polypoidal choroidal vasculopathy (PCV, n = 12), hemorrhagic choroidal neovascularization (hCNV, n = 12), pigment epithelium detachment (PED, n = 9) and type 3 MNV (RAP, n = 11). All patients received three initial aflibercept 2mg/0.05ml injections (Eylea^®) in monthly intervals (loading phase) and were subsequently treated until month 12. Measurements of arterial and venous oxygen saturation, vessel diameters and flicker response were performed using the Dynamic Vessel Analyzer (DVA; IMEDOS, Jena, Germany). Statistical analysis was performed on the total population at baseline, after loading dose and at the last follow-up visit.

Results

The arterial oxygen saturation was 94.01±2.14% and showed no change after loading dose (93.94±2.88%, p = 0.4; estimated difference [confidence interval] -0.38 [-1.24; 0.48]) and at the last visit (95.48±1.90%; p = 0.1; -1.29 [-0.34; 2.91]). The venous oxygenation during treatment was 78.49±6.93% at baseline, 80.94±7.71% after 3-monthly injections (p = 0.7; -0.43 [-2.72; 1.86]) and 80.56±7.33% at month 12 (p = 0.5; 1.07 [-2.10; 4.24). The arterial and venous vessel diameters were 94±22μm and 131±19μm at baseline, and remained unchanged following aflibercept loading dose and at the last follow-up visit (p-value: p = 0.5; 2.30 [-5.00; 9.59] p = 0.8; 0.59 [-3.17; 4.34]). During stimulation with flicker light, arterial diameter changed by +1.24±4.93% at baseline and remained stable at month 3 (+2.70±5.95%; p = 0.5; 1.43 [-2.54; 5.41]) while the change in venous diameter during flicker stimulation was +4.52±4.45% at baseline and +4.13±3.65% after loading dose (p = 0.4, 5.18 [1.73; 8.63]).

Conclusion

During intravitreal aflibercept treatment oxygen saturation, vessel diameter and flicker response did not change in the total population of patients with specific subtypes of exudative maculopathy.

Retrobulbar blood flow velocity in systemic lupus erythematosus assessed by color Doppler imaging

OBJECTIVE

To analyze the blood flow in retrobulbar vessels in systemic lupus erythematosus (SLE) by color Doppler imaging (CDI) and to investigate the associations between immunological markers, retinal abnormalities, disease activity, and vascular parameters.

METHODS

We examined 30 patients with SLE who were aged 32.1 ± 11.6 years with a disease duration of 68.0 ± 55.6 months and 30 participants in a control group. The peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI), and resistive index (RI) of the ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary arteries (PCAs) were determined. Physical and ophthalmic examinations with assessments of immunological markers were performed. All parameters were compared between SLE patients and normal controls while the correlations among parameters were analyzed.

RESULTS

In the SLE group, CDI confirmed blood flow abnormalities in the CRA and PCAs, with significantly lower blood flow velocities and increased RI and PI (p < 0.05). There was a significantly negative correlation between disease duration and EDV in the CRA, PCA, and OA (p = 0.0423, 0.0453, 0.0448). There was also a significant relationship between the SLE Disease Activity Index and the PI of the OA (p = 0.0367). The patients who had received biological agents (Rituximab) had lower EDV in the CRA and PCA (p = 0.0026, 0.028). SLE patients with kidney or CNS involvement had a significant increase in the PI in the OA (p = 0.0287). The PSV and EDV in the CRA were significantly related to creatinine (p = 0.0007 and 0.0418). We also noted a significant decreased EDV in the CRA and an increased RI in the OA among participants positive for anti-dsDNA antibodies (p = 0.0331 and 0.0228).

CONCLUSIONS

Retrobulbar circulatory disturbances were detected in SLE patients by CDI. These findings seem likely to affect smaller vessels like the CRA and PCA. However, the presence of measurable changes in the OA is generally indicative of a coexistent nephropathy or central nervous system (CNS) vasculitis. Creatinine, the disease activity index, being positive for anti-dsDNA, and receiving biological agents were associated with measurable changes on the retrobulbar blood flow.

Short-term changes in retinal and choroidal relative flow volume after anti-VEGF treatment for neovascular age-related macular degeneration

The effects of anti-vascular endothelial growth factor (anti-VEGF) agents on the native ocular vasculature are poorly understood. This pilot study aimed to assess short-term changes in retinal and choroidal perfusion after anti-VEGF treatment for neovascular exudative age-related macular degeneration (nAMD) using the relative flow volume (RFV) parameter derived from laser speckle flowgraphy. Ten treatment-naïve nAMD patients underwent measurements of mean, maximum, minimum, and differential RFV within a retinal arteriolar segment and a choroidal vessel segment outside the neovascular area. Measurement of retinal RFV (rRFV), choroidal RFV (cRFV), and subfoveal choroidal thickness (SCT) was repeated 9 and 35 days after a single anti-VEGF injection. The treatment caused a statistically significant decrease in the mean rRFV, mean cRFV, and SCT during the follow-up (p < 0.05). At the intermediate visit, the mean cRFV and SCT were − 17.6% and − 6.4% compared to baseline, respectively. However, at the final measurement, the mean cRFV was not different from the baseline value, which indicated waning of the anti-VEGF effect. In conclusion, a single anti-VEGF injection in treatment-naïve nAMD resulted in a decrease in retinal arteriolar and choroidal perfusion, according to the RFV parameter, which is a promising tool to simultaneously assess retinal and choroidal perfusion changes in response to anti-VEGF therapy.

Role of the choroidal vascularity index in branch retinal vein occlusion (BRVO) with macular edema

Purpose

To assess choroidal vasculature changes in eyes with branch retinal vein occlusion (BRVO) and macular edema (ME) using the choroidal vascularity index (CVI) and evaluate the effectiveness of CVI as a prognostic biomarker.

Methods

35 patients with monocular BRVO and ME were analyzed retrospectively. Luminal and stromal areas in choroids of swept-source optical coherence tomography were calculated using the image binarization technique. The CVI was calculated as the ratio of the luminal to total choroidal area. The CVI of BRVO and ME eyes were compared with that of the unaffected fellow and post anti-vascular endothelial growth factor (VEGF) injected eyes. A regression analysis was performed on the choroidal parameters, logMAR visual acuity (VA) two years post disease onset and central macula thickness (CMT).

Results

The CVI of BRVO and ME eyes was significantly lower than the fellow and post-injected eyes (p<0.05). The regression analysis showed a strong association between two years after logMAR VA and the CVI of fellow eyes (R² = 0.433, p<0.001). Remarkable correlations were observed in the CVI and subfoveal choroidal thickness of BRVO and ME eyes (R² = 0.189, 0.155, respectively, p<0.05). The CMT of diseased eyes were also significantly associated with the CVI of unaffected fellow eyes (R² = 0.113, p<0.05).

Conclusions

The alteration of CVI in BRVO and ME suggests that choroidal vasculature might be affected by extracellular fluid shift and VEGF changes. The fellow eye CVI could be a useful supplementary prognostic biomarker.

Color Doppler Flow Imaging of Retrobulbar Ocular Blood Flow Changes in Retinal Artery Occlusions Caused by Cosmetic Facial Filler Injections

PURPOSE

This study aimed to evaluate the effects of retinal artery occlusions caused by cosmetic facial filler injections on the retrobulbar blood flow parameters.

METHODS

This was a retrospective, noncomparative case series. Ten consecutive patients with fundus artery occlusions caused by facial filler injections were evaluated using color Doppler flow imaging (CDFI). The peak systolic velocity and end diastolic velocity of the ophthalmic artery, central retinal artery, and posterior ciliary arteries were determined. The clinical features, including the filler material, injection site, best-corrected visual acuity, fundus fluorescein angiography, and associated ocular and systemic manifestations were also collected.

RESULTS

Injected materials included autologous fat (7 cases) and hyaluronic acid (3 cases). In 6 of the patients with ophthalmic artery occlusions, the CDFI showed no or drastic declines in the retrobulbar blood flow in the ophthalmic artery, central retinal artery, and posterior ciliary arteries. In 3 of the patients with central retinal artery occlusions, the CDFI showed no or a grossly decreased retrobulbar blood flow in the central retinal artery. In one patient with anterior ischemic optic neuropathy, the CDFI showed decreased end diastolic velocities and increased pulsatility and resistance indices in the central retinal artery, posterior ciliary arteries, and ophthalmic artery. During the follow-up period, the retrobulbar blood flow recovered to some degree. Overall, ophthalmic artery occlusion patients receiving autologous fat may have neurologic complications.

CONCLUSIONS

The results suggest that the retrobulbar ocular blood flows measured with CDFI were distinctly different in the different types of ophthalmic artery occlusion. Color Doppler flow imaging could provide a practicable and convenient method for the diagnosis and follow up of retinal artery occlusions caused by cosmetic facial filler injections.

Choroidal blood flow after the first intravitreal ranibizumab injection in neovascular age-related macular degeneration patients

PURPOSE

To analyse choroidal blood flow (ChBF) changes after the first intravitreal ranibizumab injection in naïve, age-related macular degeneration (ARMD) patients.

METHODS

Subfoveal ChBF was assessed by laser Doppler flowmetry (LDF) in newly diagnosed ARMD patients. Both treated and untreated eyes were assessed in each subject at each visit before the first intravitreal ranibizumab injection as well as 24 hr (day 1) and 7 days after (day 7). Central macular thickness (CMT), best-corrected visual acuity (BVCA), systemic haemodynamic parameters and LDF parameters were evaluated at each visit. Nonparametric tests were used to compare data between visits and between treated and untreated eyes.

RESULTS

Seventeen ARMD patients were included (12 women and five men, 78 ± 8 years old). At day 7 postintravitreal ranibizumab injection, the normalized choroidal blood velocity (ChBVel) change in the treated eye group was significant (-10.2%; p = 0.006). The choroidal blood volume (ChBVol) did not change significantly after intravitreal injection of ranibizumab. There was a trend for a reduction in ChBF at day 7 (-9.1%, p = 0.08). The sensitivity of the experiment was 12% for ChBVel, 16% for ChBVol and 9% for ChBF.

CONCLUSION

In conclusion, the laser Doppler technique provides feasible and noninvasive measurements of blood flow parameters before and after intravitreal injection of antivascular endothelial growth factor (anti-VEGF) in patients with exudative ARMD. Choroidal blood velocity decreased as early as 7 days after intravitreal ranibizumab injection, suggesting a vasoconstriction effect of anti-VEGF in large choroidal vessels in front of choriocapillaris (the site of LDF measurement).

Mortality after a cerebrovascular event in age-related macular degeneration patients treated with bevacizumab ocular injections

PURPOSE

To analyse the mortality associated with intravitreal injections of bevacizumab for age-related macular degeneration (AMD) in patients previously diagnosed with stroke or transient ischaemic attack (TIA).

METHODS

We reviewed bevacizumab-treated AMD patients with a diagnosis of stroke or TIA prior to their first bevacizumab injection (n = 948). Those patients, naïve to any anti-vascular endothelial growth factor (anti-VEGF) at the time of stroke/TIA, were then compared to age- and gender-matched patients who had a stroke/TIA at the same time and had never been exposed to anti-VEGF. Survival analysis was performed using adjusted Cox regression. The main outcome measure was survival. Adjusted variables were age, smoking, alcohol abuse, hypertension, diabetes mellitus, obesity, ischaemic heart disease, congestive heart failure and liver cancer.

RESULTS

Age and gender distribution of bevacizumab-treated patients and controls were similar (mean age: 83.4 versus 83.7 years, p = 0.3; 51.7% males versus 52.5% males, p = 0.7). The adjusted mortality in patients who received bevacizumab within 3 months after stroke/TIA was significantly different than in patients non-exposed to bevacizumab (OR = 6.92, 95%, CI 1.88-25.43, p < 0.01). Within 6 months after stroke/TIA, the difference in adjusted mortality showed a strong trend (OR = 2.00, 95%, CI 0.96-4.16, p = 0.064). Within 12 months, it was insignificant (OR = 1.30, 95%, CI 0.75-2.26, p = 0.348).

CONCLUSION

We found increased mortality within three months after a cerebrovascular event in patients treated with bevacizumab for AMD compared to patients for whom there was no record of a prescription to any anti-VEGF agent.

Mortality associated with bevacizumab intravitreal injections in age-related macular degeneration patients after acute myocardial infarct: a retrospective population-based survival analysis

BACKGROUND

Intraocular injections of antivascular endothelial growth factor (VEGF) agents are currently the main therapy in age-related macular degeneration (AMD). The safety of bevacizumab, an anti-VEGF compound frequently delivered off label, is debated, particularly for high-group risks. We aim to analyze the mortality associated with intravitreal injections of bevacizumab for AMD in patients previously diagnosed with acute myocardial infarct (MI).

METHODS

In a national database, we identified bevacizumab-treated AMD patients with a diagnosis of MI prior to their first bevacizumab injection, delivered between September 2008 and October 2014 (n = 2100). We then generated sub-groups of patients treated within 3 months (n = 11), 6 months (n = 24), 12 months (n = 52), and 24 months (n = 124) after MI. Those patients were compared to age- and gender-matched members that had a MI at the same time and had never been exposed to anti-VEGF. Survival analysis was performed using propensity score-adjusted Cox regression.

RESULTS

Bevacizumab-treated patients were slightly and insignificantly older than controls (mean age 83.25 vs 83.19 year, P = .75). Gender distribution was similar. In a Cox regression adjusted with propensity score, the following differences in mortality were found: within 3 months between MI and initiation of bevacizumab treatment, OR = 6.22 (95% C.I 1.08-35.97, P < .05); within 6 months, OR = 2.37 (95% C.I 0.93-6.02, P = .071); within 12 months, OR = 3.00 (95% C.I 1.44-6.28, P < .01); within 24 months after MI, OR = 2.24 (95% C.I 1.35-3.70, P < .01); and MI any time prior to first bevacizumab injection, OR = 1.71 (95% C.I 1.53-1.92, P < .001).

CONCLUSIONS

We report increased mortality associated with the use of intravitreal bevacizumab in AMD patients after MI, compared to age- and gender-matched post-MI patients with no exposure to any anti-VEGF agent. Caution should be taken while offering bevacizumab to AMD patients after MI.

En Face Doppler Optical Coherence Tomography Measurement of Total Retinal Blood Flow in Diabetic Retinopathy and Diabetic Macular Edema

Importance

Alterations in ocular blood flow play an important role in the pathogenesis and progression of diabetic retinopathy (DR). However, the measurement of retinal blood flow in clinical studies has been challenging. En face Doppler optical coherence tomography (OCT) provides an effective method for measuring total retinal blood flow (TRBF) in the clinic.

Objective

To investigate TRBF in eyes with DR of varying severity, with or without diabetic macular edema (DME), using en face Doppler OCT.

Design, Setting, and Participants

This was a cross-sectional study conducted from May 23, 2014, to January 11, 2016, which analyzed 41 eyes with DR from 31 diabetic patients, 20 eyes without DR from 11 diabetic patients, and 16 eyes from 12 healthy age-matched controls, all at the New England Eye Center in Boston, Massachusetts.

Main Outcomes and Measures

Participants were imaged with a high-speed, swept-source OCT prototype at 1050-nm wavelength using repeated en face Doppler OCT raster scans, comprising 600 × 80 axial scans and covering a 1.5 × 2-mm2 area centered at the optic disc. The TRBF was automatically calculated using custom Matlab software.

Results

This study included 41 eyes with DR from 31 diabetic patients (mean [SD] age, 62.8 [13.4] years; 12 were female patients), 20 eyes without DR from 11 diabetic patients (mean [SD] age, 58.8 [10.1] years; 5 were female patients), and 16 eyes from 12 healthy age-matched controls (mean [SD] age, 57.9 [8.1] years; 8 were female participants). The mean (SD) TRBF was 28.0 (8.5) µL/min in the eyes with DME, 48.8 (13.4) µL/min in the eyes with DR but without DME, 40.1 (7.7) µL/min in the diabetic eyes without retinopathy, and 44.4 (8.3) µL/min in age-matched healthy eyes. A difference in TRBF between the eyes with DME that were treated and the eyes with DME that were not treated was not identified. The TRBF was consistently low in the eyes with DME regardless of DR severity. The eyes with moderate nonproliferative DR but without DME exhibited a wide range of TRBF from 31.1 to 75.0 µL/min, with the distribution being highly skewed.

Conclusions and Relevance

High-speed en face Doppler OCT can measure TRBF in healthy and diabetic eyes. Diabetic eyes with DME exhibited lower TRBF than healthy eyes (P ≤ .001). Further longitudinal studies of TRBF in eyes with DR would be helpful to determine whether reduced TRBF is a risk factor for DME.

Effect of intravitreal aflibercept (Eylea®) on retrobulbar hemodynamics in patients with neovascular age-related macular degeneration

PURPOSE

To investigate the short-term effect of single intravitreal aflibercept injection on retrobulbar blood flow in patients with neovascular age-related macular degeneration (nAMD).

METHODS

Twenty eyes of 20 patients with nAMD scheduled for single intravitreal aflibercept (Eylea^®) injection and 20 fellow eyes (uninjected) were enrolled in this prospective interventional study. The hemodynamic parameters of the ophthalmic artery (OA), central retinal artery (CRA) and posterior ciliary artery (PCA) comprising peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) were measured by using color Doppler ultrasonography (CDU) in both injected and uninjected fellow eyes at baseline and 1 week after the injection.

RESULTS

The measured first-week values of PSV and EDV in the CRA, OA and PCA showed a statistically significant reduction when comparing baseline values in both injected and uninjected fellow eyes (p = 0.0001). Also, it was found a significant increase in the post-injection RI values of all the CRA, OA, PCA in injected eye and OA in the uninjected eye (p = 0.0001). There was any significant difference between pre- and post-injection RI values of the CRA and PCA in the fellow eyes (p = 0.137, p = 0.736, respectively).

CONCLUSION

Single intravitreal administration of aflibercept alters retrobulbar blood flow velocities (BFVs) in both injected and uninjected fellow eyes in the short-term period.

Ocular Pulse Amplitude and Retinal Vessel Caliber Changes after Intravitreal Dexamethasone Implant

Purpose:

The purpose of this study is to evaluate possible changes in ocular pulse amplitude (OPA), retinal arteriole caliber (RAC), and retinal venule caliber (RVC), following the intravitreal injection of dexamethasone implants (DIs).

Methods:

Thirty-four eyes of 34 patients with macular edema were included. All participants received a full ophthalmologic examination at baseline. RAC and RVC were measured via optical coherence tomography; OPA and intraocular pressure (IOP) were measured via dynamic contour tonometry at baseline, month 1, and month 3. Statistical analysis was performed for before-after comparison of OPA, IOP, RAC, and RVC measurements.

Results:

The mean OPA (in order to baseline, month 1, month 3) was 2.8 ± 0.8, 2.9 ± 1.0, 2.9 ± 0.9. The mean IOP was 16.8 ± 2.9, 17.3 ± 2.7, 18.4 ± 2.9 mmHg. The mean RAC was 97.8 ± 9.2, 97.2 ± 9.0, 97.6 ± 9.4. The mean RVC was 124.4 ± 8.2, 124.8 ± 8.8, 123.8 ± 8.2. There were no statistically significant changes in RAC (P = 0.688), RVC (P = 0.714), OPA (P = 0.348), and IOP (P = 0.115). There was also no correlation between RAC and OPA (r = 0.12, P = 0.62) or RVC and OPA (r = 0.16, P = 0.68) at the last visit.

Conclusion:

The intravitreal injection of DI does not significantly affect RAC, RVC, or OPA, which indicates that the treatment does not alter overall retinal-choroidal vasculature or hemodynamics.

Effects of intravitreal ranibizumab on the untreated eye and systemic gene expression profile in age-related macular degeneration

The purpose of this study was to evaluate the systemic effects of intravitreal ranibizumab (Lucentis) treatment in patients with neovascular age-related macular degeneration (AMD). The impact of intravitreal ranibizumab injections on central retinal thickness (CRT) of treated and contralateral untreated eyes, and differences in gene expression patterns in the peripheral blood mononuclear cells were analyzed. The study included 29 patients aged 50 years old and over with diagnosed neovascular AMD. The treatment was defined as 0.5 mg of ranibizumab injected intravitreally in the form of one injection every month during the period of 3 months. CRT was measured by optical coherence tomography. The gene expression profile was assigned using oligonucleotide microarrays of Affymetrix HG-U133A. Studies have shown that there was a change of CRT between treated and untreated eyes, and there were differences in CRT at baseline and after 1, 2, and 3 months of ranibizumab treatment. Three months after intravitreal injection, mean CRT was reduced in the treated eyes from 331.97±123.62 to 254.31±58.75 μm, while mean CRT in the untreated fellow eyes reduced from 251.07±40.29 to 235.45±36.21 μm at the same time. Furthermore, the research has shown that among all transcripts, 3,097 expresses change after the ranibizumab treatment in relation to controls. Among these transcripts, 1,339 were up-regulated, whereas 1,758 were down-regulated. Our results show the potential systemic effects of anti-VEGF therapy for AMD. Moreover, our study indicated different gene expression in peripheral blood mononuclear cells before and after intravitreal ranibizumab treatment.

The effect of intravitreal vascular endothelial growth factor on inner retinal oxygen delivery and metabolism in rats

Vascular endothelial growth factor (VEGF) is stimulated by hypoxia and plays an important role in pathologic vascular leakage and neovascularization. Increased VEGF may affect inner retinal oxygen delivery (DO2) and oxygen metabolism (MO2), however, quantitative information is lacking. We tested the hypotheses that VEGF increases DO2, but does not alter MO2. In 10 rats, VEGF was injected intravitreally into one eye, whereas balanced salt solution (BSS) was injected into the fellow eye, 24 h prior to imaging. Vessel diameters and blood velocities were determined by red-free and fluorescent microsphere imaging, respectively. Vascular PO2 values were derived by phosphorescence lifetime imaging of an intravascular oxyphor. Retinal blood flow, vascular oxygen content, DO2 and MO2 were calculated. Retinal arterial and venous diameters were larger in VEGF-injected eyes compared to control eyes (P < 0.03), however no significant difference was observed in blood velocity (P = 0.21). Thus, retinal blood flow was greater in VEGF-injected eyes (P = 0.007). Retinal vascular PO2 and oxygen content were similar between control and VEGF-injected eyes (P > 0.11), while the arteriovenous oxygen content difference was marginally lower in VEGF-injected eyes (P = 0.05). DO2 was 950 ± 340 and 1380 ± 650 nL O2/min in control and VEGF-injected eyes, respectively (P = 0.005). MO2 was 440 ± 150 and 490 ± 190 nL O2/min in control and VEGF-injected eyes, respectively (P = 0.31). Intravitreally administered VEGF did not alter MO2 but increased DO2, suggesting VEGF may play an offsetting role in conditions characterized by retinal hypoxia.

Effect of intravitreal bevacizumab on retrobulbar blood flow of patients with diabetic macular edema

PURPOSE

To determine the effect of intravitreal bevacizumab on retrobulbar blood flow of patients with diabetic macular edema.

METHODS

Peak systolic velocity, end-diastolic velocity, resistance, and pulsatility indices of central retinal artery (CRA), nasal posterior ciliary artery (NPCA), temporal posterior ciliary artery (TPCA), and ophthalmic artery (OA) were assessed by color Doppler ultrasonography in injected and uninjected eyes of 37 patients at baseline and at day 1 and day 7 after the injection.

RESULTS

At day 1 after the injection, peak systolic and end diastolic velocities of the CRA and NPCA in the injected eyes and peak systolic velocity of NPCA in the uninjected eyes decreased significantly (p&lt;0.05, p = 0.025, respectively). Peak systolic and end diastolic velocities were not significantly different in the injected and uninjected eyes at day 7 after the injection (p&gt;0.05). In the injected eyes, there was no significant change in resistance and pulsatility indices (p&gt;0.05), but a decrease in resistance index of NPCA and resistance and pulsatility indices of TPCA occurred in uninjected eyes at day 7 after the injection (p = 0.016, p = 0.023, and p = 0.025, respectively).

CONCLUSIONS

Intravitreal bevacizumab affects retrobulbar blood flow in injected and uninjected eyes of patients with diabetic macular edema.

Changes in retinal blood flow in patients with macular edema secondary to branch retinal vein occlusion before and after intravitreal injection of bevacizumab

PURPOSE

To investigate the effect of intravitreal bevacizumab (IVB) injections for macular edema secondary to acute branch retinal vein occlusion on the retinal microcirculation.

METHODS

The study was a prospective, interventional case series. Central macular thickness using spectral-domain optical coherence tomography and retinal blood flow (RBF) in untreated eyes with macular edema secondary to acute branch retinal vein occlusion in occluded (V1) and opposite venules in affected eyes (V2) and the equivalent venules in contralateral eyes (V3), using laser Doppler velocimetry during follow-up and after IVB injection, were measured.

RESULTS

In 33 eyes with acute branch retinal vein occlusion of <2 months of duration at the first visit, changes in the retinal microcirculation for 1 month was observed; the macular edema improved spontaneously, and the RBF was unchanged in 15 of 33 eyes, and the RBF increased by 23.3% in 18 eyes with persistent macular edema. Twenty-four eyes received an IVB injection (1.25 mg per 0.05 mL). The RBF did not change significantly during follow-up. In 8 of 24 eyes (33%) with improved macular edema 3 months after the treatment, the average RBF values before injection were significantly higher compared with that of eyes with recurrent edema.

CONCLUSION

One IVB injection might have little effect on the retinal microcirculation in patients with macular edema secondary to acute branch retinal vein occlusion at least 3 months after the injection. However, the increased RBF in the occluded venules before injection might be associated with improved macular edema after the IVB injection.

Ocular pulse amplitude and retinal vessel caliber changes after intravitreal ranibizumab

The purpose of the present study was to examine the effects of intravitreal ranibizumab on ocular pulse amplitude (OPA) and retinal vessel caliber (RVC) in wet age-related macular degeneration (AMD). Thirty-two eyes of 32 wet AMD patients were included in this case series. Three consecutive monthly injections of ranibizumab were performed. The OPA was measured with the Pascal dynamic contour tonometer. RVC measurements were taken with spectral-domain optical coherence tomography. Pre-injection mean OPA value was 2.55 ± 0.76 mmHg and post-injections mean OPA value was 2.79 ± 0.88 mmHg at the last visit (p = 0.10). Pre-injection mean arteriole and venule RVC were 96.7 ± 9.4 and 125.9 ± 8.4 µm; while post-injections arteriole and venule RVC were 96.0 ± 8.7 and 125.6 ± 8.9 µm, respectively (p > 0.05). OPA and RVC are unchanged after triple intravitreal ranibizumab injections, indicating that this treatment does not significantly alter gross retina-choroidal vasculature and hemodynamics.

The effect of intravitreal bevacizumab on ocular blood flow in diabetic retinopathy and branch retinal vein occlusion as measured by laser speckle flowgraphy

Background

This study evaluated the effect of intravitreal injection of bevacizumab (IVB) on macular edema associated with diabetic retinopathy (DME) or branch retinal vein occlusion (BRVOME) using laser speckle flowgraphy.

Methods

A comparative interventional study of 25 eyes from 22 patients with macular edema (DME group: 12 eyes; BRVOME group: 13 eyes) who underwent IVB. Mean blur rate (MBR) was measured in the retinal artery, retinal vein, optic nerve head (ONH), and choroid before and after IVB.

Results

In the BRVOME group, there was no significant change in MBR in the retinal artery, retinal vein or ONH, but choroidal MBR decreased significantly (P=0.04). In the DME group, the MBR in the retinal artery, retinal vein, ONH, and choroid decreased significantly (P=0.02, P=0.04, P<0.001, and P=0.04, respectively). In the DME group, pre-IVB MBR in the ONH was significantly correlated with post-IVB foveal thickness (R= −0.71, P=0.002). There was no such correlation in the BRVOME group in the ONH.

Conclusion

IVB had a suppressive effect on circulation in eyes with DME but not in those with BRVOME. This suggests that this noninvasive and objective biomarker may be a useful part of pre-IVB evaluations and decision-making in DME.

Fellow eye effect of unilateral intravitreal bevacizumab injection in eyes with diabetic macular edema

AIMS

Anti-vascular endothelial growth factor compounds are routinely used for the treatment of diabetic macular edema (DME). We aim to evaluate for the existence and magnitude of treatment effect on fellow un-injected eyes.

METHODS

A consecutive group of patients with bilateral DME who received unilateral bevacizumab injections was retrospectively evaluated. Data collected included demographics, ophthalmic and systemic findings, and optical coherence tomography (OCT) measurements of macular thickness.

RESULTS

Thirty-five patients were evaluated. Mean follow-up was 245 days (range: 30-800), and the mean number of bevacizumab injections was 3.6 (range: 1-11). At end of follow-up, the mean (SD) OCT central subfield thickness reduced by 72 ± 112 micron in the injected eye (from 469 ± 139 to 397 ± 120 micron; P=0.001), while in the non-injected eye it reduced by 49 ± 75 micron (from 380 ± 130 to 331 ± 106 micron; P<0.001). Sixteen injected eyes (45.7%) showed central subfield thickness reduction of ≥50 micron while 10 (28.6%) non-injected eyes showed such thickness reduction. Improved VA following treatment was detected in 14 (40%) injected eyes and in 15 (43%) non-injected eyes.

CONCLUSIONS

Unilateral bevacizumab injections in patients with bilateral DME are often associated with bilateral response.

SUMMARY STATEMENT

Anti-vascular endothelial growth factor compounds are routinely used for the treatment of diabetic macular edema (DME). In this retrospective study, we show that unilateral bevacizumab injections often result in reduction of the macular thickness in the fellow un-injected eye.

Serum concentration of vascular endothelial growth factor after bilateral intravitreal injection of bevacizumab

Purpose

This study compared serum vascular endothelial growth factor (VEGF) concentration between patients given the bilateral and unilateral intravitreal injections of bevacizumab.

Methods

In a prospective manner, serum VEGF levels in treatment-naive patients with age-related macular degeneration who underwent bilateral or unilateral intravitreal injections of bevacizumab were investigated. After informed consent, peripheral blood was collected from in patients who underwent bilateral or unilateral intravitreal injection of bevacizumab before and 1 month after the injection. Serum VEGF levels were measured by enzyme-linked immunosorbent assay after centrifugation. In addition, best-corrected visual acuity (BCVA) and central retinal thickness (CRT) before and 1 month after the injection were compared between each group.

Results

Twenty patients received bilateral injections (40 eyes) and 20 patients received unilateral injections. The VEGF concentrations (pg/mL) before the bilateral injection were 235.75 ± 183.16 and 252.53 ± 233.52 for the unilateral injection. They were significantly reduced to 153.88 ± 113.26 and 189.42 ± 251.72 after 1 month, respectively (p = 0.037 and 0.019), which are showing no significant difference between the two groups (p = 0.771). And there were no significant intergroup difference in pre- and postoperative BCVA and CRT.

Conclusions

The bilateral simultaneous intravitreal injection of bevacizumab did not differ greatly from unilateral intravitreal injection in the influence on serum VEGF levels and the therapeutic outcome.

Can intravitreal ranibizumab alter retrobulbar circulation in eyes with age-related macular degeneration?

PURPOSE

To determine the effect of a single intravitreal ranibizumab injection on retrobulbar circulation in cases with neovascular age-related macular degeneration (AMD).

METHODS

In this prospective and interventional study, 32 patients with neovascular AMD were enrolled. A single intravitreal ranibizumab dose was in only 1 eye per patient. Peak systolic velocity, end-diastolic velocity, resistive index and pulsatility index values in the common carotid artery, ophthalmic artery, central retinal artery, nasal posterior ciliary artery, and temporal posterior ciliary artery in both injected and uninjected healthy fellow eyes were measured using color Doppler ultrasonography at baseline and 1 week and 1 month after the injection of ranibizumab.

RESULTS

All measurements revealed no statistically significant difference among baseline, first week, and first month after injection measurements for all parameters measured in all arteries in both the injected and uninjected healthy fellow eyes.

CONCLUSION

A single intravitreal injection of ranibizumab does not significantly affect on retrobulbar circulation of either the injected or the uninjected healthy fellow eyes with neovascular AMD.

Effects of bevacizumab in retina and choroid after intravitreal injection into monkey eyes

OBJECTIVE

Due to its low price, bevacizumab, which binds vascular endothelial growth factor, is currently used off-label for the treatment of over 50 different eye diseases and has been adopted worldwide despite the absence of serious preclinical data. This study examines the effects of intravitreal bevacizumab on monkey eyes with particular focus on choroidal and retinal vessels.

METHODS

Cynomolgus monkeys received an intravitreal injection of 1.25 mg bevacizumab with or without (125)I labeling. The eyes were enucleated between 1 and 14 days after injection and were investigated by electron microscopy, immunocytochemistry, histochemistry or autoradiography. Untreated and phosphate buffered saline (PBS)-injected monkeys were used as controls.

RESULTS

Bevacizumab locally accumulated at high concentration within individual blood vessels. It formed electron-dense deposits inside retinal veins and between red and white blood cells, activated thrombocytes and induced retinal vein thrombosis. Retinal cells like Müller cells, astrocytes and microglia were also activated. High amounts of bevacizumab were found in retinal and choroidal vessels which may interfere with blood flow.

CONCLUSIONS

The deposits on the retinal vein walls may provide a mechanistic basis for the observed retinal blood flow alterations after bevacizumab treatment in patients.