Analysis of Outcomes for Intravitreal Bevacizumab in the Treatment of Choroidal Neovascularization Secondary to Ocular Histoplasmosis

INTRAVITREAL ANTIVASCULAR ENDOTHELIAL GROWTH FACTOR FOR THE TREATMENT OF CHOROIDAL NEOVASCULARIZATION SECONDARY TO OCULAR HISTOPLASMOSIS: Ten-Year Follow-Up

PURPOSE

To assess the long-term efficacy of intravitreal antivascular endothelial growth factor injections (IVI), alone or in combination with verteporfin photodynamic therapy (IVI/PDT), for management of choroidal neovascularization secondary to presumed ocular histoplasmosis syndrome (POHS).

METHODS

Retrospective, comparative, interventional case series analyzing 82 eyes in 74 patients treated with either IVI or IVI/PDT for presumed ocular histoplasmosis syndrome choroidal neovascularization from January 2006 to January 2021.

RESULTS

The average logarithm of the minimum angle of resolution VA in year 5 was 0.40 (20/50) and 0.52 (20/67) for IVI versus IVI/PDT groups, respectively ( P = 0.33), and in year 10 was 0.53 (20/58) and 0.64 (20/86), respectively ( P = 0.50). The average number of annual injections over the first 5 years of follow-up was 3.3 versus 1.7 for IVI versus IVI/PDT groups, respectively ( P < 0.001), and over 10 years was 3.3 versus 1.6, respectively ( P < 0.001). Treatment-free interval of 5 years was reached by 39% versus 60% in IVI versus IVI/PDT groups, respectively ( P = 0.95).

CONCLUSION

Our study found both IVI and IVI/PDT to be effective in long-term management of presumed ocular histoplasmosis syndrome choroidal neovascularization, with a fewer number of annual injections and longer treatment-free interval in the combination group. However, given the limitations of a retrospective study, a prospective randomized study is necessary to determine whether the addition of PDT significantly decreases treatment burden.

A Review of Local Therapy for the Management of Cystoid Macular Edema in Uveitis

ABSTRACT

Uveitic macular edema is a significant cause of visual impairment in most uveitis types. Treatment options of uveitis have advanced remarkably in recent years. Up to now, corticosteroids remain the mainstay of treatment. Nonsteroidal immunomodulators, and recently the biologic agents, which can reinforce efficacy and enable discontinuation or reduction of steroids to maintenance doses, are becoming increasingly popular in the management of uveitic macular edema. Several medications can be used in intraocular delivery and more and more sustained releasing implants are being developed. This review will briefly focus on the review of local therapy for the management of cystoid macular edema in uveitis, as many of these novel approaches are currently being evaluated in clinical trials.

Pathogenesis of ocular toxoplasmosis

Ocular toxoplasmosis is a retinitis -almost always accompanied by vitritis and choroiditis- caused by intraocular infection with Toxoplasma gondii. Depending on retinal location, this condition may cause substantial vision impairment. T. gondii is an obligate intracellular protozoan parasite, with both sexual and asexual life cycles, and infection is typically contracted orally by consuming encysted bradyzoites in undercooked meat, or oocysts on unwashed garden produce or in contaminated water. Presently available anti-parasitic drugs cannot eliminate T. gondii from the body. In vitro studies using T. gondii tachyzoites, and human retinal cells and tissue have provided important insights into the pathogenesis of ocular toxoplasmosis. T. gondii may cross the vascular endothelium to access human retina by at least three routes: in leukocyte taxis; as a transmigrating tachyzoite; and after infecting endothelial cells. The parasite is capable of navigating the human neuroretina, gaining access to a range of cell populations. Retinal Müller glial cells are preferred initial host cells. T. gondii infection of the retinal pigment epithelial cells alters the secretion of growth factors and induces proliferation of adjacent uninfected epithelial cells. This increases susceptibility of the cells to parasite infection, and may be the basis of the characteristic hyperpigmented toxoplasmic retinal lesion. Infected epithelial cells also generate a vigorous immunologic response, and influence the activity of leukocytes that infiltrate the retina. A range of T. gondii genotypes are associated with human ocular toxoplasmosis, and individual immunogenetics -including polymorphisms in genes encoding innate immune receptors, human leukocyte antigens and cytokines- impacts the clinical manifestations. Research into basic pathogenic mechanisms of ocular toxoplasmosis highlights the importance of prevention and suggests new biological drug targets for established disease.

MANAGEMENT OF NEOVASCULAR OCULAR HISTOPLASMOSIS: Past and Present

PURPOSE

To review the wide variety of treatment modalities available for choroidal neovascularization secondary to the presumed ocular histoplasmosis syndrome.

METHODS

A literature search was performed to review the multitude of studies conducted to investigate the efficacy and safety of treatment modalities available for choroidal neovascularization secondary to the presumed ocular histoplasmosis syndrome.

RESULTS

Each treatment modality is reviewed, with the studies summarized and presented to support or refute the method of treatment. Two case reports are presented to demonstrate the treatment regimens.

CONCLUSION

This is a comprehensive review of the treatment modalities available to address choroidal neovascularization secondary to the presumed ocular histoplasmosis syndrome. Investigators will continue to strive toward higher efficacy and safety with future innovations in the field.

Treatment of CNV secondary to presumed ocular histoplasmosis with intravitreal aflibercept 2.0 mg injection

OBJECTIVE

To assess the efficacy and safety of intravitreal aflibercept injection in the treatment of CNV secondary to presumed ocular histoplasmosis syndrome (POHS).

PURPOSE

To assess safety of intravitreal aflibercept for the treatment of CNV secondary to presumed ocular histoplasmosis syndrome.

METHODS

Masked, open-label, prospective study. Five subjects will receive 2.0 mg aflibercept injection every 8 weeks with 3 initial monthly doses over a 12 month period.

RESULTS

No adverse systemic or ocular were reported. At month six, the mean visual acuity improved by 7.8 ETDRS letters, mean central subfoveal thickness decreased by 38.8 microns and mean OCT volume decreased by 0.076 mm3 . At month twelve, the mean visual acuity improved by 12.4 ETDRS letters, mean central subfoveal thickness decreased by 34.6 microns and mean OCT volume decreased by 0.576 mm3.

CONCLUSION

The use of intravitreal 2.0 mg aflibercept injection for the treatment of CNV secondary to presumed ocular histoplasmosis syndrome yielded no systemic or ocular adverse events and produced improvement in visual acuity and reduction of OCT thickness and volume.

Intravitreal anti-vascular endothelial growth factor for choroidal neovascularization in ocular histoplasmosis

PURPOSE

To report eight cases of long-term successful treatment of choroidal neovascularization because of ocular histoplasmosis syndrome with intravitreal anti-vascular endothelial growth factor agents.

METHODS

Retrospective case series. This article reviewed the course of eight eyes in seven patients who underwent intravitreal injection of bevacizumab and/or ranibizumab for treatment of choroidal neovascularization secondary to ocular histoplasmosis syndrome. Outcomes were assessed using pre- and post-anti-vascular endothelial growth factor visual acuities.

RESULTS

Eight eyes in seven patients were found to have new ocular histoplasmosis syndrome-associated subfoveal choroidal neovascularization lesions, as evidenced on clinical examination, fluorescein angiography, and optical coherence tomography. Intravitreal anti-vascular endothelial growth factor injections were used as initial or early treatment with successful resolution of the choroidal neovascularization lesions in most cases. Mean visual acuity improved from 20/60 to 20/47 over an average of 121.4 weeks. Either bevacizumab or ranibizumab was administered with an average of 2.6 injections per year of follow-up. Three eyes (37.5%) experienced a gain in visual acuity with a mean increase of 7.7 lines, 1 eye (12.5%) experienced no change, and 2 eyes (25%) experienced a loss of visual acuity of 2 or more lines. Six eyes (75%) were able to avoid mild visual loss (2 lines or less).

CONCLUSIONS

Intravitreal anti-vascular endothelial growth factor agents may successfully treat or at least stabilize neovascular complications of ocular histoplasmosis syndrome when used as a first-line treatment.

Anti-VEGF therapies in the treatment of choroidal neovascularisation secondary to non-age-related macular degeneration: a systematic review

OBJECTIVES

The aim of this study is to systematically review the evidence for anti-vascular endothelial growth factor (VEGF) therapy in choroidal neovascularisation secondary to conditions other than age-related macular degeneration.

DATA SOURCES

MEDLINE, MEDLINE in-process, EMBASE and CENTRAL databases and conference abstracts were searched (from inception to Jan 2014).

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS

Randomised and non-randomised comparative studies with follow-up of at least 6 months were included and were used to assess clinical effectiveness.

STUDY APPRAISAL AND SYNTHESIS METHOD

Risk of bias was assessed using the Cochrane risk of bias tool and modified Newcastle-Ottawa Scale. Meta-analysis was not possible due to methodological heterogeneity.

RESULTS

16 studies met the inclusion criteria (1091 eyes; 963 pathological myopia, 74 other conditions). There was large variation in risk of bias across studies. An improvement in best-corrected visual acuity in anti-VEGF arms over comparators was reported in all studies. The proportion of patients improving by at least 15 letters in anti-VEGF arms ranged from 27.3% to 70%. There were no significant differences between bevacizumab and ranibizumab.

LIMITATIONS

Owing to the rarity of choroidal neovascularisation secondary to conditions other than age-related macular degeneration or pathological myopia, there are unlikely to ever be sufficiently powered trials in these populations.

CONCLUSIONS

Bevacizumab and ranibizumab appear to be effective in improving visual acuity for patients with choroidal neovascularisation secondary to conditions other than age-related macular degeneration. The evidence base is strongest for choroidal neovascularisation secondary to pathological myopia, however, based on current evidence and likely pharmacological pathways, clinicians should consider treatment with either bevacizumab or ranibizumab for rarer causes.

Albuminated PLGA nanoparticles containing bevacizumab intended for ocular neovascularization treatment

Bevacizumab, an anti-VEGF antibody, has demonstrated trustworthy effects in treatment of retinal and choroidal neovascularization that both are crucial sight threatening conditions. However, the weak point is the short half-life of the drug in vitreous which necessitates frequent intravitreal injections. Accordingly employing controlled-release drug delivery systems such as polymeric nanoparticles (NPs) has been suggested. In this study albuminated-PLGA-NPs containing bevacizumab were prepared and studied intended for reducing the number of injections. NPs were formulated by double-emulsion method and a single dose of NPs was intravitreally injected to rabbits. The drug concentrations in vitreous and aqueous humor were assayed in different time intervals using ELISA and intraocular pharmacokinetic parameters were calculated. Moreover, coumarin-6 loaded albuminated-PLGA-NPs were employed to evaluate the distribution and persistence of the NPs in the posterior segment. Results revealed that the bevacizumab vitreous concentration maintained above 500 ng mL(-1) for about 8 weeks and 3.3 times elevation was observed in the drug vitreous MRT compared with the control. According to coumarin-6 NP tests, fluorescence emissions in posterior tissues were observed for 56 days which confirmed the nanoparticles persistence in ocular tissues during the test span. Therefore our prepared formulation may offer improvements in treatment of eye posterior segment neovascularization.

Gender differences in birdshot chorioretinopathy and the white dot syndromes: do they exist?

Inflammatory conditions that affect the posterior pole are diverse. Specifically, birdshot chorioretinopathy and the white dot syndromes present with multiple white dots in the fundus. These diseases appear to affect similar age groups but there is question as to whether or not a difference exists between the genders. This review summarizes the current studies on birdshot chorioretinopathy and the white dot syndromes as they are related to gender, exploring the differences, if any, which may exist between prevalence, clinical presentation, and treatment response for these diseases. Though the specific etiology of these diseases remains unclear, future treatments may be guided as to how these diseases affect the sexes differently.

Lentivirus vector-mediated knockdown of erythropoietin-producing hepatocellular carcinoma receptors B4 inhibits laser-induced choroidal neovascularization

PURPOSE

To evaluate the efficacy of erythropoietin-producing hepatocellular carcinoma receptors B4 (EphB4) knockdown on the development of laser-induced choroidal neovascularization (CNV) in vivo.

METHODS

We constructed recombinant lentiviral vectors (Lv) Lv-shRNA-EphB4 to specifically knock down the expression of EphB4. The mRNA and protein expression of EphB4 was investigated by real-time reverse transcription-polymerase chain reaction (RT-PCR) and western blot. CNV was induced by laser photocoagulation in C57BL/6 mice. The mice were then randomly assigned to be intravitreally injected with phosphate-buffered saline (PBS), Lv-shRNA-EphB4 recombinant lentivirus, or an unrelated shRNA recombinant lentivirus (pFU LV-shRNA-NC). An uninjected group was used as the control. Fundus fluorescein angiography (FFA), histologic analysis, and choroidal flat mounts analysis were applied to evaluate the inhibition of CNV after an intravitreal injection.

RESULTS

Transfection of Lv-shRNA-EphB4 led to the knockdown of EphB4, and EphB4 mRNA was down-regulated by about 80%. FFA and histologic analysis revealed that the leakage areas and the mean thickness of CNV were much smaller in the Lv-shRNA-EphB4 group than in the PBS-treated, pFU Lv-shRNA-NC group and the non-injection group. Choroidal flat mounts showed significantly less leakage and smaller leakage areas in the Lv-shRNA-EphB4 group than those in other groups.

CONCLUSION

Knocking down the expression of EphB4 exerts an inhibitory effect on CNV in vivo. It may provide a potential strategy for the treatment of CNV.