Hemodynamic response to intravitreal triamcinolone in eyes with macular edema

The short-term effects of intravitreal aflibercept injections and dexamethasone implant on ocular hemodynamics in retinal vein occlusions

Purpose

To determine the early effects of intravitreal anti-VEGF and dexamethasone application on blood flow velocities in patients with retinal vein occlusions.

Methods

The ophthalmic (OA) and the central retinal arteries (CRAs) of the affected and unaffected eyes of 21 patients with central retinal vein occlusion (CRVO), and 26 patients with branch retinal vein occlusion (BRVO) were investigated by Color Doppler imaging (CDI). Peak systolic volume (PSV), end diastolic volume (EDV), and average blood velocity (Vmean) of the CRA and OA were measured and resistive indexes (RI) were calculated at pre-injection and the 1st week and 1st month post-injection.

Results

There was no statistically significant difference between the OA values for affected and unaffected eyes in the CRVO group before treatment. The CRA, EDV, and Vmean values were significantly lower in affected eyes. Blood flow velocities of both CRA and OA were not significantly different than in the fellow unaffected eyes in the BRVO group. The differences between PSV, EDV, and Vmean measurements of OA and CRA at different times pre- and post-injection in response to anti-VEGF and dexamethasone treatment in the CRVO group were significant; but there was no difference in RI value. OA blood flow velocity measurements were not statistically different post-injection in the BRVO group; however, the values of PSV and EDV of CRA decreased post-injection.

Conclusion

Intravitreal anti-VEGF and dexamethasone implant may induce retinal arteriolar vasoconstriction in patients with retinal vein occlusion.

The impact of intravitreal dexamethasone implant (Ozurdex®) on retrobulbar hemodynamics in patients with diabetic macular edema and retinal vein occlusions

Objective: To evaluate the effect of single intravitreal dexamethasone implant (Ozurdex^®) on ocular blood flow velocities in patients with diabetic macular oedema (DME) and retinal vein occlusions (RVO). Methods: This prospective non-randomized interventional study included injected and fellow eyes of 12 patients with DME and of 16 patients with RVO treated with intravitreal Ozurdex^®. Colour Doppler Ultrasonography (CDU) measures of the central retinal artery (CRA), posterior ciliary artery (PCA), ophthalmic artery (OA) those are peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) were performed in both injected and uninjected eyes before injection, at one week, one month after injection, and prior to re-injection. Results: Inter-eye comparison of all the measured CDU data (baseline, first week, first month, reinjection) showed no statistically significant difference in both DME and RVO group. PSV and EDV values of the CRA, OA, and PCA showed a decreasing trend in the first week and first-month visits and then increased at reinjection time. RI and PI measures of the CRA, OA, and PCA measures showed minimal alterations in the follow-up. But all these differences were not statistically significant. Significant visual gain and anatomic recovery were obtained by the intravitreal dex-implant both in the DME and RVO group. Conclusions: Single intravitreal dex-implant did not alter ocular blood flow in the treatment of macular oedema due to RVO and diabetes.

Vessel diameter study: intravitreal vs posterior subtenon triamcinolone acetonide injection for diabetic macular edema

PurposeTo detect and compare the vessel diameter effect of intravitreal vs subtenon injection of triamcinolone for diabetic macular edema (DME).MethodsSixty patients with DME who underwent triamcinolone injection either intravitreally (N=30) or under the tenon capsule (N=30) were included. Non-injected fellow eyes served as control. The main outcome measures were central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and artery-vein ratio (AVR).ResultsIn the intravitreal group, pre-injection mean CRAE (147.07 μ) decreased to 141.03 μ at 1 week and to 139.43 μ at 1 month (P<0.001) while baseline CRVE (209.61 μ) decreased initially to 198.85 μ at 1 week then to 198.49 μ at 1 month (P<0.001). In the subtenon group, pre-injection CRAE (152.18 μ) decreased to 149.49 μ at 1 week and to 147.47 μ at 1 month (P=0.017), while baseline CRVE (215.60 μ) decreased initially to 208.69 μ at 1 week then to 207.25 μ at 1 month (P=0.003). Pre-injection AVR values did not change at 1 week and at 1 month in both injection groups (P=0.66 and P=0.196, respectively). In the control group, none of the 3 parameters changed throughout the study period compared to the baseline (P>0.28).ConclusionIn eyes with DME, both intravitreal and subtenon triamcinolone injection led to a significant constriction of retinal arteries and veins.

Short-term effects of intravitreal triamcinolone acetonide injection on ocular blood flow evaluated with color Doppler ultrasonography

AIM

To evaluate the changes in ocular blood flow with color Doppler ultrasonography (CDU) after intravitreal triamcinolone acetonide (IVTA) injection.

METHODS

A total of 46 patients who underwent IVTA (4 mg/0.1 mL) injection for diabetic macular edema (DME) (n=22), central retinal vein occlusion (CRVO) (n=12) and choroidal neovascular membrane (CNVM) (n=12) were included in the study. Peak systolic velocity (PSV), end diastolic velocity (EDV) and resistivity index (RI) were measured from the ophthalmic artery (OA), the central retinal artery (CRA) and the posterior ciliary artery (PCA) of each patient with CDU before, at the end of the first week and at the end of the first month following IVTA injection.

RESULTS

In the DME group, PSV of OA at the first of the first month (mean±SD) (37.48±10.87 cm/s) increased compared to pre-injection value (31.39±10.84 cm/s) (P=0.048). There was a statistically significant decrease (P=0.049) in PSV of CRA at the end of the first month (7.97±2.67 cm/s) compared to the pre-injection (9.47±3.37 cm/s). There was not any statistically significant difference on the other parameters in the DME group. Also, there was not any statistically significant difference on the ocular blood flow values in the CRVO and CNVM groups.

CONCLUSION

We observed that 4 mg/0.1 mL IVTA increased PSV of OA and decreased PSV of CRA in DME patients and did not have any effect on ocular blood flow values of CRVO and CNVM patients.

Impact of intravitreal triamcinolone acetonide versus intravitreal bevacizumab on retrobulbar hemodynamic in patients with diabetic macular edema

PURPOSE

To evaluate and compare retrobulbar hemodynamic changes measured with color Doppler imaging (CDI) in diabetic patients receiving intravitreal triamcinolone acetonide (IVTA) versus bevacizumab.

METHODS

Patients with diffuse diabetic macular edema were assessed prospectively by CDI following intravitreal injection of triamcinolone acetonide (group I, 12 eyes) versus bevacizumab (group II, 14 eyes). CDI was used to measure the peak systolic velocity (PSV), end diastolic velocity (EDV) and the resistive index (RI) of the central retinal artery (CRA), ophthalmic artery (OA) and posterior ciliary arteries (PCA) one day preoperatively and one week postoperatively.

RESULTS

In group I, EDV of OA and CRA decreased significantly (p = 0.007 and 0.018, respectively). The PSV and RI of PCA decreased significantly (p = 0.035 and 0.002, respectively). In group II, both the PSV and EDV of the CRA decreased significantly (p = 0.000). Comparing the percentage of change in both groups, PSV of the CRA decreased significantly in group II (p = 0.034), while IVTA has more significant effect on the ophthalmic artery hemodynamic parameters as EDV decreased and RI increased significantly (p = 0.045 and 0.043, respectively)

CONCLUSION

Intravitreal injections of triamcinolone acetonide and bevacizumab have a significant effect on the ocular hemodynamic. The effect of bevacizumab is statistically significant on the PSV of CRA compared to IVTA.

Evaluation of retrobulbar blood flow by color doppler ultrasonography after intravitreal ranibizumab injection in patients with neovascular age-related macular degeneration

PURPOSE

This study aimed to evaluate the changes in retrobulbar blood flow by using color Doppler sonography in patients who had undergone intravitreal ranibizumab injection for neovascular age-related macular degeneration (AMD).

METHODS

The study comprised 37 AMD patients who had undergone intravitreal 0.5 mg ranibizumab injection. The ophthalmic artery, central retinal artery, and short lateral posterior ciliary artery of both eyes of patients were evaluated by color Doppler sonography. Peak systolic velocity, end-diastolic velocity, and resistance index were calculated before injection, and after injection on day 7 and day 30. The pre- and postinjection values were compared using Wilcoxon signed rank test.

RESULTS

In a comparison with the preinjection values of peak systolic velocity, end-diastolic velocity, and resistance index, the postinjection values at both day 7 and day 30 showed no statistically significant difference in ophthalmic artery, lateral posterior ciliary artery, and central retinal artery (p > 0.05). Similarly, for the same parameters, pre- and postinjection values in the uninjected fellow eye showed no statistically significant difference (P > 0.05).

CONCLUSIONS

Intravitreal ranibizumab injection for neovascular AMD does not cause a significant change in the retrobulbar blood flow in either the injected eye or the fellow eye.

Use of colour Doppler imaging in ocular blood flow research

The main objective of this report is to encourage consistent quality of testing and reporting within and between centres that use colour Doppler imaging (CDI) for assessment of retrobulbar blood flow. The intention of this review is to standardize methods in CDI assessment that are used widely, but not to exclude other approaches or additional tests that individual laboratories may choose or continue to use.

Does ranibizumab (Lucentis®) change retrobulbar blood flow in patients with neovascular age-related macular degeneration?

PURPOSE

To investigate the effects of intravitreal ranibizumab on retrobulbar blood flow in patients with neovascular age-related macular degeneration (AMD).

METHODS

Thirty-one eyes of 30 patients with neovascular AMD were examined prospectively by both color Doppler imaging and fundus fluorescein angiography. Color Doppler imaging was used to measure the maximum and minimum velocities of the central retinal vein, peak systolic/end-diastolic velocities of blood flows, and pulsatility index and resistivity index values in the central retinal artery, nasal/temporal posterior ciliary arteries (NPCA/TPCA) and ophthalmic artery. The t test for paired samples was used for comparing retrobulbar blood flow values before and after intravitreal ranibizumab (Lucentis®) injection in the study and control groups.

RESULTS

There was a statistically significant (p < 0.05) difference between the pre-injection and post-injection end-diastolic velocities of the NPCA and TPCA and resistivity index values of TPCA. The other parameters showed no statistically significant difference.

CONCLUSION

Our results show that intravitreal ranibizumab injection increases retrobulbar blood flow.

Pharmacokinetics of triamcinolone acetonide for the treatment of macular edema

INTRODUCTION

The use of intravitreal triamcinolone acetonide (TA) for the treatment of various types of macular edema has been widespread, particularly for the last decade. Currently, there is a scant amount of evidence-based literature evaluating the pharmacokinetic profile of TA despite clinical data showing the efficacy of intravitreal TA for multiple forms of macular edema.

AREAS COVERED

This paper is an extensive review of human and experimental studies published on the pharmacokinetics of TA for the treatment of macular edema. The literature search was conducted via OVID, TRIP Database and EMBASE, up to April 2011.

EXPERT OPINION

The pharmacokinetic profile of TA is unpredictable and the agent has a time-limited therapeutic action due to its relatively short half-life. This has led to the need for repeated injections. Future research should investigate the pharmacokinetic profiles of TA when administered intravitreally, as well as through alternate routes in more robust studies.

A comparison of three different intravitreal treatment modalities of macular edema due to branch retinal vein occlusion

PURPOSE

To compare the efficacy of intravitreal injection of triamcinolone, bevacizumab, and a combination of triamcinolone-bevacizumab for the management of macular edema due to branch retinal vein occlusion.

METHODS

Fifty-two eyes of 52 patients (29 male, 23 female) with branch retinal vein occlusion and macular edema were included. Patients received one of the following intravitreal treatments: 4 mg triamcinolone acetonide monotherapy (n=17), 1.25 mg bevacizumab monotherapy (n=14) or a combination of 2 mg triamcinolone acetonide and 1.25 mg bevacizumab (n=21). Measurements of Snellen visual acuity and central macular thickness with optical coherence tomography were done at baseline, and at months one, three, and six.

RESULTS

At baseline, the three groups did not differ in age (P=0.12), duration of macular edema (P=0.24), visual acuity (P=0.62), central macular thickness (P=0.16), and intraocular pressure (P=0.15). All study groups showed significant reduction of central macular thickness (P=0.02, P=0.02, and P=0.001, respectively) and improvement in visual acuity (P=0.02, P= 0.02 and P=0.02, respectively) one month after injection. At six months, there was a significant reduction in central macular thickness (P=0.02, P=0.02, and P=0.04, respectively) while only bevacizumab monotherapy group demonstrated significant improvement in visual acuity (P=0.01).

CONCLUSION

Intravitreal injection of triamcinolone, bevacizumab or combination of triamcinolone-bevacizumab appears to have similar therapeutic effects on macular edema due to branch retinal vein occlusion at one month. Intravitreal injection of bevacizumab yielded better results of visual acuity than the others at six months.

Effects of intravitreal bevacizumab (Avastin) therapy on retrobulbar blood flow parameters in patients with neovascular age-related macular degeneration

BACKGROUND

To investigate the effects of intravitreal bevacizumab on retrobulbar circulation in patients with neovascular age-related macular degeneration (AMD).

METHOD

Thirty patients with neovascular age-related macular degeneration were assessed prospectively by both color Doppler imaging and fundus fluorescein angiography. Spectral Doppler analysis allowed the measurement of the maximum velocity (Vmax) and minimum velocity (Vmin) of the central retinal vein (CRV), and peak systolic (PSV), end-diastolic (EDV) velocities of blood flows, and pulsatility index (PI) and resistance index (RI) values in the central retinal artery (CRA), nasal and temporal posterior ciliary arteries (NPCA, TPCA), and ophthalmic artery (OA). The t test for paired samples was used to compare retrobulbar blood flow values before and after intravitreal bevacizumab injection.

RESULT

PSV and EDV of the NPCA and PSV of the TPCA were significantly decreased after intravitreal bevacizumab injection (p < 0.05). There was no statistically significant difference in the other parameters.

CONCLUSION

Our results suggest that intravitreal bevacizumab therapy has a measurable effect on retrobulbar blood flow.

Effect of triamcinolone acetonide on vascular endothelial growth factor and occludin levels in branch retinal vein occlusion

PURPOSE

To investigate the molecular mechanism by which triamcinolone acetonide (TA) may reduce edema in a porcine model of branch retinal vein occlusion (BRVO).

DESIGN

Animal study.

METHOD

After baseline ophthalmoscopic examination and fundus photography, a BRVO was created photothrombotically in each eye of 6 pigs, using argon green photocoagulation and intravenous Rose Bengal. Following this, the left eye was injected intravitreally with 4 mg/0.1 ml TA. After 11 weeks, the eyes were re-examined. Fluorescein angiography, in addition to ophthalmoscopy and fundus photography, was performed. Following sacrifice of the animals, the eyes were enucleated and processed. The distribution of vascular endothelial growth factor (VEGF), occludin, and glial fibrillary acidic protein (GFAP) were localized by immunofluorescence cytochemistry on 10 microm frozen retinal sections of TA-treated and untreated eyes.

RESULTS

Retinal VEGF levels were significantly lower in the TA-treated eyes as compared with the untreated eye (P = .002). Conversely occludin levels were significantly higher in the treated eye (P = .026). There was also a significant reduction in GFAP immunoreactivity in the Muller cells of the treated eyes (P = .015) with no statistical significance in the astrocytes (P = .065).

CONCLUSION

Intravitreal TA down regulates VEGF, which may prevent a decrease in occludin and also inhibits an increase in GFAP expression in Muller cells. These events may contribute to a reduction in the blood retinal barrier breakdown that occurs in BRVO and promote resolution of the associated retinal edema.