Comparison of foveal-sparing with foveal-involving photodynamic therapy for myopic choroidal neovascularization

Recent Advances in Photodynamic Therapy for Vascular Abnormalities

Abstract Background: Photodynamic therapy (PDT) is a minimally invasive therapy that was gradually established as a first-line treatment for vascular abnormalities. Its action depends on the appropriate wavelength of light and photosensitizer to produce toxic oxygen species and cause cell death. Objective: Several new clinical improvements and trends in PDT have been described in recent years. The aim of this review is to provide an overview of the current data from clinical trials. Methods: In this review, we introduce and generalize the wavelength, duration, dose, strength, and photosensitizer of PDT for the treatment of vascular abnormalities, such as circumscribed choroidal hemangiomas (CCH), choroidal neovascularization (CNV) and capillary malformation (CM). Results: The systematic review findings indicate that the application of PDT is a safe effective method to treat CCH, CNV and CM. However, PDT also has early onset side effects and late onset side effects. Conclusions: Based on the discussion of the effectiveness of PDT, we conclude that PDT has great potential for clinical use, although PDT has possible side effects.

Pilot study of ziv-aflibercept in myopic choroidal neovascularisation patients

Background

Myopic choroidal neovascularization (CNV) is the most common sight-threatening complication associated with high myopia. The present study evaluated the efficacy and safety of the intravitreal injection of ziv-aflibercept in patients with myopic CNV.

Methods

This prospective interventional study was conducted on 20 eyes of 20 patients with active myopic CNV. Twelve patients were 40 years or older. This study was performed in the Ophthalmology Department of Tanta University Eye Hospital, Tanta University, Egypt. Optical coherence tomography (OCT) was performed for all patients at baseline and monthly after injection during the 6-month follow up period. The main outcome measures were changes in BCVA and CMT. The exploratory outcome measures were CNV size, IOP and the number of injections needed in each age group during the study period.

Results

Patients with myopic CNV younger than 40 years needed fewer injections (2.00 ± 0.76) than patients older than 40 years (2.50 ± 1.00), with no statistical significance detected between the two groups (p-value 0.246). CNV was smaller in the younger age group (p-value 0.209), best corrected visual acuity (BCVA) improved significantly in the younger and older age groups (p-values 0.001 and 0.028, respectively), and central macular thickness (CMT) decreased significantly after 6 months, from 242.88 ± 23.83 μm to 191.13 ± 13.83 μm in the younger age group and from 251.33 ± 26.60 μm to 197.08 ± 17.64 μm in the older age group (p = 0.001). No significant correlation was found between the final BCVA and either the spherical equivalent or central macular thickness after 6 months, with p-values of 0.135 and 0.145, respectively. No significant changes in IOP were detected in either group after the intravitreal injection.

Conclusion

Ziv-aflibercept is a highly effective and safe drug in cases of active myopic CNV; however, a larger number of patients and a longer follow-up period are needed to confirm our results.

This study was retrospectively registered at clinicaltrials.gov (ID: NCT04290195) on 26-2-2020.

Pharmacotherapy of Myopic Choroidal Neovascularization

BACKGROUND

Myopic choroidal neovascularization (CNV) is a common cause of central visual loss in patients with high myopia, and the most common form of CNV in younger individuals. Pharmacologic therapy is the current mainstay of treatment of these patients.

METHODS

Review of pharmacological treatment options for myopic CNV, which primarily involves intravitreal administration of anti-vascular endothelial growth factor (anti-VEGF) agents.

RESULTS

At this time, anti-VEGF therapy agents are the first-line therapy in these patients. Comparative trials have not identified any major differences in treatment outcomes between aflibercept, bevacizumab, and ranibizumab. Only ranibizumab is approved for this indication in the US. Best visual outcomes are associated with younger age, smaller lesion size, and absence of chorioretinal atrophy.

CONCLUSION

Anti-VEGF therapy is generally very effective in the treatment of myopic CNV.

Anti-vascular endothelial growth factor therapy for the treatment of myopic choroidal neovascularization

Myopic choroidal neovascularization (CNV) is a sight-threatening condition which occurs in eyes with myopia, particularly in those with pathologic myopia. It is the most common cause of CNV among patients younger than 50 years. Hemorrhage and exudation from the CNV lesion may eventually result in scarring or chorioretinal atrophy. While myopic CNV was previously treated with focal laser photocoagulation or photodynamic therapy (PDT), the current treatment of choice is anti-vascular endothelial growth factor (VEGF) agents. Many studies have demonstrated the efficacy of intravitreal anti-VEGF agents in the treatment of myopic CNV. The RADIANCE study reported that intravitreal ranibizumab was superior to PDT in eyes with myopic CNV (at 3 months, both groups receiving intravitreal ranibizumab gained 10.5 and 10.6 letters vs 2.2 letters among patients receiving PDT). In addition, the study demonstrated similar visual outcomes in eyes treated on the basis of visual acuity stabilization or disease activity criteria. Other clinical studies have provided evidence for the efficacy of ranibizumab and aflibercept in the treatment of myopic CNV. This review addresses the epidemiology, pathophysiology, and imaging characteristics of myopic CNV, and discusses the evidence for the efficacy of anti-VEGF agents as compared to laser photocoagulation and PDT.

Comparability of retinal thickness measurements using different scanning protocols on spectral-domain optical coherence tomography

Retinal thickness measurements obtained using optical coherence tomography (OCT) play an essential role both in multi-center clinical trials and in normal clinical practice. Different scanning protocols are available on most OCT devices, and it is important to ascertain whether the retinal thickness measurements obtained from these are comparable. This study aimed to compare retinal thickness measurements between raster and radial scanning protocols using spectral-domain OCT (SD-OCT). In a prospective study, 32 healthy subjects were scanned sequentially using raster and radial protocols from a SD-OCT device. For both the raster and radial OCT scans, retinal thicknesses were measured manually subfoveally and at 12 other points at 0.5 mm intervals temporally and nasally on the horizontal OCT B-scan passing through the fovea. The retinal thickness measurements were compared using intraclass correlation (ICC) and Bland-Altman plots. Subfoveal retinal thickness was 227.0 µm when measured on the raster scan and 229.2 µm on the radial scan, with a mean difference of 2.2 µm (P = 0.141).The ICC for agreement was 0.889 (95 % confidence interval 0.818-0.933). Similar results were observed for retinal thickness measurements at all other points, with mean differences ranging from -3.37 to 2.59 µm, and ICC values ranging from 0.837 to 0.972. The retinal thickness measurements obtained by the raster and radial scans of the same SD-OCT device are comparable, with differences of less than 4 µm. This is of relevance when measurements made using different OCT scan protocols are compared.

The role of anti-VEGF agents in myopic choroidal neovascularization: Current standards and future outlook

INTRODUCTION

The global prevalence of pathologic myopia is 0.9-3.1%, and visual impairment is found in 0.1-0.5% of European and 0.2-1.4% of Asian studies. Myopic choroidal neovascularization (mCNV) affects 5.2-11.3% of pathologic myopia patients and is a leading cause of vision impairment in the working-age population. Characteristic morphological changes and visual-acuity decrease are diagnostic features. Vascular-Endothelial-Growth-Factor (VEGF) has been identified as a trigger for pathologic neovascularization in these highly myopic patients.

AREAS COVERED

We cover the epidemiology, pathology and diagnostic aspects of mCNV. The history of therapeutic interventions is described, followed by an overview of current standard-of-care (SOC)-blocking VEGF using bevacizumab (off-label), ranibizumab or aflibercept and improving vision up to 13.5-14.4 letters. Despite good efficacy, an unmet medical need remains. We summarize ongoing and future developments of new drugs to treat or potentially cure mCNV.

EXPERT OPINION

mCNV is a major global health concern. Early detection and treatment is key for a satisfying outcome. The current SOC, VEGF inhibitors, affords good therapeutic efficacy and reasonable disease stabilization with few intravitreal treatments per year. However, the long-term prognosis is still unsatisfactory, and side-effects like chorioretinal atrophy development are of concern. Therefore, efforts should be intensified to develop more effective therapies.