Lack of Therapeutic Effect of Ranibizumab in Fellow Eyes After Intravitreal Administration

Factors affecting prognosis and need for anti-vascular endothelial growth factor injections in wet age-related macular degeneration

PURPOSE

To understand factors affecting visual prognosis and the number of intravitreal antivascular endothelial growth factor (anti-VEGF) injections needed to stabilize wet age-related macular degeneration (AMD).

METHODS

In this retrospective cohort, 119 treatment-naïve wet AMD patients were followed for two years. In patients with bilateral disease, the eye with worse best-corrected visual acuity (BCVA) or that received more intravitreal injections was recruited as the study eye. In all visits, BCVA was recorded, ophthalmological examination was performed including macular optical coherence tomography imaging. Twenty health status/lifestyle questions were asked to the patients via phone as potential risk factors. All patients received 3 loading doses of intravitreal bevacizumab injections and received repeat injections of aflibercept or ranibizumab when the eye had a new, active neovascular lesion.

RESULTS

Patients who took regular micronutrition had similar visual outcome and injection numbers compared to the ones who did not. Patients with bilateral disease needed less intravitreal injections compared to unilateral AMD patients (p = 0.016) and women on hormone replacement therapy (HRT) required less injections compared to the women who were not (p = 0.024). Female patients had a mean gain of 2.7 letters while male patients lost 3.8 letters (p = 0.038). Wet AMD started at an earlier age in smokers (p = 0.002). Patients with a better education level presented earlier with better BCVA (p = 0.037).

CONCLUSION

HRT and anti-VEGF injections to the fellow eye improved the prognosis of wet AMD, while male patients had slightly worse prognosis. Estrogen's protective effects and potential contribution in wet AMD needs further attention. Retrospectively registered: 2020/0622.

Effect of intravitreal injection of bevacizumab in treated and untreated eyes of Black African patients with polypoidal choroidal vasculopathy

OBJECTIVE

To evaluate the response of polypoidal choroidal vasculopathy (PCV) in eyes treated with intravitreal bevacizumab (BVZ) and untreated fellow eyes in black Africans.

METHODS

We studied 22 eyes (12 patients) divided into 12 treated and 10 untreated eyes from January 2017 to January 2020. Treated eyes received 1 monthly injection of BVZ 2.5mg for 3 months, with optional additional injections depending on the patient's course. Both groups of eyes were evaluated at presentation and then at 3, 6, 9, and 12 months after treatment. Outcome measures were visual acuity (VA) and ophthalmoscopic and OCT findings.

RESULTS

The mean age of the patients was 66.3±5.6 years. In treated eyes, VA remained stable from 0.10±0.12 at baseline to 0.20±0.30 at month 12, P=0.84. VA was stable in 83.3% and improved in 16.7% of eyes. On OCT, 41.7% of eyes showed decreased and another 41.7% disappearance of subretinal fluid (SRF) at 12 months. Pigment epithelial detachment (PED) height decreased in 9 eyes (75.0%) but remained unchanged in 3 eyes (25%). In untreated eyes, no difference was observed between the baseline (0.53±0.42) and 12-month VA (0.58±0.40), P=0.82. VA improved in 2 eyes, decreased in one eye, and remained unchanged in 7 eyes. OCT lesions remained stable in 6 eyes. The PED enlarged in one eye but remained stable in 3 other eyes.

CONCLUSION

Intravitreal injection of BVZ 2.5mg led to stabilization of VA, resorption of SRF, and reduction in the size of the PED in the majority of eyes with PCV but was ineffective on the polyps. The one-year prognosis in untreated eyes with PCV was favorable and marked by functional and structural stability.

Incidence and risk factors for neovascular age-related macular degeneration in the fellow eye

PURPOSE

The epidemiology, risk factors, and the effect of anti-VEGF treatment on neovascular age-related macular degeneration (nAMD) have primarily been studied in the first eye developing the disease. The understanding of pathophysiology and planning of follow-up examinations can be improved by knowledge of incidence and risk factors for development of the disease in the fellow eye.

METHODS

In a prospective observational cohort study, epidemiological and clinical risk factors for the development of nAMD in the fellow eye among 2516 patients consecutively diagnosed with the disease from a population of 0.9 million citizens during a period of more than 10 years were studied.

RESULTS

nAMD had been diagnosed in the fellow eye of 541 (21.5%) of the patients. The incidence of fellow-eye involvement increased from approximately 5% in patients initially presenting with bilateral disease to approximately 28% more than 6 years after the diagnosis in the first eye. Visual acuity (VA) was higher and central retinal thickness (CRT) was lower in fellow eyes with nAMD diagnosed later than the first eye. Male gender, increasing leakage area, and peripapillary location of the subretinal neovascular membrane in the first eye reduced the risk of developing disease in the fellow eye.

CONCLUSIONS

The planning of follow-up examinations of patients diagnosed with nAMD in one eye should consider that the risk of fellow-eye involvement is higher within the first 6 years, in women, and when the leakage area in the first eye is small and not located peripapillary.

Therapeutic Effect of Anti-VEGF for Age-Related Macular Degeneration in the Untreated Fellow Eye

Intravitreal injections of antivascular endothelial growth factor (anti-VEGF) agents have been reported to occasionally produce a therapeutic effect in the uninjected fellow eye. Here, three patients with bilateral neovascular age-related macular degeneration are presented. In all three patients, unilateral anti-VEGF injection resulted in bilateral reduction of macular thickness as measured by spectral domain optical coherence tomography.

Assessment of Corneal Sensation, Innervation and Retinal Nerve Fiber Layer in Patients Treated with Multiple Intravitreal Ranibizumab Injections

PURPOSE

To evaluate the effects of repeated intravitreal ranibizumab injections on corneal sensitivity, corneal sub-basal nerve plexus (SBNP) and peripapillary retinal nerve fiber layer (RNFL) thickness in patients with neovascular age-related macular degeneration (AMD).

METHODS

Sixty-six eyes of 33 patients who had received unilateral repeated intravitreal ranibizumab injections (0.5 mg/0.05 ml) for the treatment of AMD and 25 eyes of 25 healthy subjects were included in the study. Central corneal sensation was measured using the contact Cochet-Bonnet esthesiometer. The laser scanning in vivo corneal confocal microscope was used to determine corneal SBNP parameters. The peripapillary RNFL thickness was assessed with spectral-domain optical coherence tomography. Data obtained from the ranibizumab-injected eyes were compared with those of the fellow non-treated eyes and the eyes of the healthy control subjects.

RESULTS

The mean number of ranibizumab injections per eye was 8.9±5.0 (range 3-20). There were no statistically significant differences in the central corneal sensitivity threshold and corneal SBNP parameters between the ranibizumab-injected eyes and the fellow untreated eyes or between those with neovascular AMD and the healthy control group (P>0.05 for all). The average peripapillary RNFL thickness of the treated eyes did not differ significantly to the fellow eyes (P = 0.237), and the eyes of healthy control subjects (P = 0.918). There were no significant correlations between the number of ranibizumab injections and any of the study parameters.

CONCLUSIONS

Multiple intravitreal injections of ranibizumab seem to have no harmful effects on corneal sensitivity, innervation and peripapillary RNFL thickness in patients with AMD.

Predictors of Outcome in Patients with Neovascular Age-Related Macular Degeneration Switched from Ranibizumab to 8-Weekly Aflibercept

PURPOSE

The purpose of this study was to evaluate the outcomes over 12 months in patients with neovascular age-related macular degeneration (nAMD) with insufficient response to ranibizumab who were switched directly to 8-weekly fixed dosing of aflibercept without a loading phase.

DESIGN

Retrospective interventional study.

PARTICIPANTS

Consecutive patients with nAMD who were switched from pro re nata (PRN) intravitreal ranibizumab to 8-weekly fixed aflibercept because of persistent disease activity from November 1, 2013, to September 30, 2014, were included.

METHODS

Demographic data, visual acuity (VA), and spectral-domain optical coherence tomography characteristics over time were evaluated to determine the prognostic indicators of final visual outcome at 12 months.

MAIN OUTCOME MEASURES

The VA, central subfield thickness (CST), presence of macular fluid at month 12 compared with baseline, and the definition of prognostic indicators of final visual outcome at month 12.

RESULTS

A total of 431 patients (447 eyes) were included in this study. There was no statistically significant difference in VA between baseline and month 12 (P = 0.79), whereas the CST significantly decreased at month 12 compared with baseline (P < 0.001). At the 12-month follow-up, 48.3% of eyes had no macular fluid compared with 8.5% at baseline. The mean number of injections at month 12 was 6.8±1.75. Poor prognostic indicators included increasing age, increasing CST, the presence of intraretinal fluid, pigment epithelial detachment, and subfoveal thickening.

CONCLUSIONS

Patients who have not yet "responded" to PRN ranibizumab seem to exhibit retinal dehydration after switching to aflibercept, whereas there was no demonstration of VA benefit. Baseline features at the point of switching can independently predict outcomes.

The effect of intravitreal bevacizumab and ranibizumab on macular edema of the contralateral eye: A comparative study of two anti-VEGFs

Purpose:

To compare the effects of bevacizumab and ranibizumab on the visual function and macular thickness in the contralateral (untreated) eye of patients with bilateral diabetic macular edema (DME).

Materials and Methods:

Thirty-nine patients with bilateral DME, who had been treated with both bevacizumab and ranibizumab in the same eye, were considered retrospectively for this study. Recorded outcome measurements included the best-corrected visual acuity (BCVA) assessment with the Early Treatment Diabetic Retinopathy Study (ETDRS) chart and the central subfield macular thickness (CSMT) measurement of the contralateral, uninjected eye before and at 4 weeks after the injections.

Results:

The median BCVA of the uninjected eye was 50 ETDRS letters and the median CSMT was 459 μm preceding the bevacizumab injection whereas at the control appointment, 4 weeks after the injection, the median BCVA had increased to 52 letters (P = 0.098), and the median CSMT had decreased to 390 μm (P = 0.036). The mean interval between the bevacizumab and ranibizumab treatments was 4.79 ΁ 1.52 months. The measurements of the untreated eye after the ranibizumab treatment showed that the median BCVA decreased from 55 to 52 letters, and the median CSMT increased from 361 μm to 418 μm (P = 0.148 and P = 0.109, respectively).

Conclusions:

In contrast to ranibizumab, the intravitreal administration of bevacizumab resulted in a statistically significant decrease in macular thickness in the untreated eye in patients with bilateral 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.

Pharmacokinetics, pharmacodynamics and pre-clinical characteristics of ophthalmic drugs that bind VEGF

Drugs that prevent the binding of VEGF to its trans-membrane cognate receptors have revolutionized the treatment of the most important chorioretinal vascular disorders: exudative age-related macular degeneration, diabetic macular edema, and retinal vein occlusions. Pegaptanib, which binds to VEGF165 and longer isoforms, ranibizumab and bevacizumab, which bind all VEGF-A isoforms, and aflibercept, which binds VEGF-A, VEGF-B, and placental growth factor, all bind VEGF165 with high affinity. The drugs have relatively long half-lives (7 to 10 days) after intravitreal depot injections and clinical durations of action that usually exceed 4 weeks. Plasma VEGF concentrations decrease after intravitreal injections of bevacizumab and aflibercept because their systemic half-lives are extended by their Fc fragments. Extensive in vitro and in vivo testing shows that the drugs prevent VEGF-mediated activation of endothelial cells while exhibiting little evidence of toxicity. Further anti-VEGF drug development is on-going.

Biological, preclinical and clinical characteristics of inhibitors of vascular endothelial growth factors

Vascular endothelial growth factor (VEGF) plays an important role in the pathophysiology of several sight-threatening retinal disorders such as age-related macular degeneration, diabetic macular edema and proliferative diabetic retinopathy. The discovery of anti-VEGF agents has revolutionized our treatment of these conditions. There are 4 anti-VEGF agents that are either approved or in common use in ophthalmology, namely pegaptanib (Macugen, Pfizer), ranibizumab (Lucentis, Novartis), aflibercept or VEGF Trap-Eye (EYLEA, Bayer) and bevacizumab (Avastin, Roche). There are differences between them. In this review, the differences are discussed in detail. Furthermore, an attempt is made to explain some of the clinical trial data based on their differences in ocular efficacy, duration of action, and local and systemic safety concerns.

Effectiveness of ketorolac tromethamine in prevention of severe retinopathy of prematurity

PURPOSE

This study assessed the effectiveness of the use of ketorolac tromethamine to reduce retinopathy of prematurity (ROP) incidence and its progression to more severe forms.

METHODS

Forty-seven preterm newborn infants with a birth weight (BW) of 1,000 grams or less and/or a gestational age (GA) of 29 weeks or less were enrolled in the study when avascular retina zone I or ROP any stage were diagnosed at screening. Studied infants were randomized to receive ketorolac tromethamine ophthalmic solution in one eye and a drop of placebo in the other eye, until ROP requiring treatment or full retinal vascularization was diagnosed.

RESULTS

Only 2 newborn infants did not develop ROP. Among 45 newborn infants who developed ROP, 6 showed different ROP staging between the two eyes, 4 of which had a better outcome in the eye receiving ketorolac tromethamine. The differences between ROP stagings were not significant even when analyzed by GA and BW subgroups. No significant treatment-related side effects occurred.

CONCLUSION

This report suggests that ketorolac tromethamine ophthalmic solution cannot reduce the risk of developing severe ROP in preterm infants.

Preclinical aspects of anti-VEGF agents for the treatment of wet AMD: ranibizumab and bevacizumab

Three anti-vascular endothelial growth factor (VEGF) therapies are currently used for the treatment of patients with wet age-related macular degeneration (AMD): pegaptanib, ranibizumab, and bevacizumab. Ranibizumab is an antibody fragment approved for the treatment of wet AMD. Bevacizumab is a full-length antibody registered for use in oncology but unlicensed for wet AMD. However, it is used off-label worldwide not only for wet AMD but also for various other ocular diseases associated with macular edema and abnormal vessel growth. We consider aspects of ranibizumab and bevacizumab in relation to their molecular characteristics, in vitro and in vivo properties, and preclinical safety data. Before 2009, most studies described the short-term toxicity of bevacizumab in multiple cell types of the eye. Since 2009, an increasing number of studies have compared the properties of ranibizumab and bevacizumab and investigated their impact on retinal cell functioning. Compared with bevacizumab, ranibizumab neutralizes VEGF better at low concentrations, maintains efficacy for longer, and has a higher retinal penetration and potency. Studies in animals demonstrate ranibizumab to be better localized to the injected eye, whereas bevacizumab appears to have a greater effect in the fellow eye. In humans, a localized and systemic effect has been reported for both molecules. In conclusion, overlapping yet distinct pharmacological properties of ranibizumab and bevacizumab indicate that safety or efficacy data from one cannot be extrapolated to the other.