Retinal venular calibre dilatation after intravitreal ranibizumab treatment for neovascular age-related macular degeneration

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.

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).

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.

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 effects of ranibizumab injections on fluorescein angiographic findings and visual acuity recovery in age-related macular degeneration

Aim

The objective of the study reported here was to evaluate the effect of ranibizumab on retinal circulation times and vessel caliber and to analyze the correlation of these factors with visual acuity (VA) prognosis in patients with age-related macular degeneration (AMD).

Subjects and methods

This prospective cohort study included 52 eyes of 46 patients (mean age 73.5 years [standard deviation 7.7]; 28 males, 18 females). The study parameters were best-corrected visual acuity (BCVA), central macular thickness (CMT) (pre- and posttreatment: for 3 months after the last injection), retinal circulation times, diameter of retinal arteriole (DRA), and diameter of retinal vein (DRV) (pre- and posttreatment: after a loading dose of three consecutive injections of ranibizumab with a 4-week interval in the initial phase). The pretreatment, posttreatment measurements, and their differences were recorded for analyses. The injections were repeated when needed. Eyes were grouped into one of two groups according to VA recovery: Group 1, cases showing significant recovery of VA (n=21, 37%), and Group 2, cases showing preservation of VA (n=22, 42%) and deterioration of VA (n=11, 21%). Differences were compared statistically in and between groups. Logistic regression analysis was undertaken to determine the correlation of these parameters with VA recovery.

Results

There was a significant reduction in DRA (P=0.007) and CMT levels (P<0.001) in both study groups after treatment. When the two groups were compared, the differences in pretreatment values of DRA (P=0.001), DRV (P=0.017), CMT (P=0.039), and mean BCVA (P=0.00) were found to be statistically significant. Posttreatment changes in DRA (P=0.013) and mean CMT (P=0.010) were found to be factors related to VA recovery by logistic regression analysis.

Conclusion

Our findings reveal that ranibizumab treatment is associated with decrease in DRA, CMT, and significant improvement in VA recovery. Further, taking into account the cases in which VA was preserved, when needed, ranibizumab should be re-injected after the loading dose.

VEGF-A polymorphisms predict short-term functional response to intravitreal ranibizumab in exudative age-related macular degeneration

AIM

To investigate the association between VEGF gene SNPs and early response to intravitreal ranibizumab for exudative age-related macular degeneration.

MATERIALS & METHODS

Sixty-four patients (64 eyes) were prospectively enrolled and treated for neovascular age-related macular degeneration with ranibizumab monotherapy. Visual acuity was measured using the ETDRS chart. A loading phase of 3 monthly intravitreal injections of ranibizumab 0.5 mg/0.05 ml was performed. The analyzed VEGF-A gene SNPs were rs699947 (-2578A/C) and rs1570360 (-1154G/A); the allelic discrimination was performed in real-time PCR platform. The difference of best corrected visual acuity (ETDRS letters) read before and after treatment was considered as functional outcome.

RESULTS

Ranibizumab was significantly more effective as measured by best corrected visual acuity in patients harboring the VEGF-A -2578C allele (from +6.26 to +7.44 ETDRS letters), whereas patients carrying the VEGF-A -2578AA genotype revealed an absence of early functional response to ranibizumab (-1.78 ETDRS letters; p = 0.0192).

CONCLUSION

This study suggests that the VEGF-A -2578A/C SNP may represent an important molecular determinant of the early functional outcome of ranibizumab. Original submitted 3 December 2012; Revision submitted 18 February 2013.