Intra- and subretinal neovascularization following radiation therapy: Contribution of OCT-angiography

[Radiation-induced retinopathy: actual knowledge and new concepts]

Radiation retinopathy is an occlusive vascular pathology following radiotherapy, generally targeted on the eye or peri-ocular structures. Despite increasingly precise techniques (stereotactic radiosurgery, proton therapy, etc.), the inclusion of the retina in the radiation field is sometimes unavoidable. This can lead to a severe pathology, which can ultimately cause blindness or even the anatomical loss of the eye when neovascular glaucoma occurs, due to the abnormal proliferation of neovessels. Radiation retinopathy have been described for more than a century, but it has recently seen great advances in both diagnosis and treatment. The advances of efficient and less invasive examinations in our clinical practice, such as OCT-angiography, allows for easier screening and diagnosis at earlier stages. Thus a new approach to the pathology is necessary, first of all through new definitions and classifications including previously undetected minimal forms. Furthermore, the recent appearance of intravitreal therapies by injection of anti-VEGF or dexamethasone implants has drastically changed the visual prognosis of these patients, who were previously treated only by retinal photocoagulation of the ischaemic areas. Recent studies have even shown the effectiveness of these new molecules in preventing the development of radiation retinopathy. This review of the literature provides an update on this disease and details how these recent diagnostic and therapeutic developments may play a role in the management of this complication.

Non-Cancer Effects following Ionizing Irradiation Involving the Eye and Orbit

Simple Summary

The irradiation of tumors involving the eye or orbit represents a complex therapeutic challenge due to the proximity between the tumor and organs that are susceptible to radiation. The challenges include tumor control, as it is often a surrogate for survival; organ (usually the eyeball) preservation; and the minimization of damage of sensitive tissues surrounding the tumor in order to preserve vision. Anticipation of the spectrum and severity of radiation-induced complications is crucial to the decision of which technique to use for a given tumor. The aim of the present review is to report the non-cancer effects that may occur following ionizing irradiation involving the eye and orbit and their specific patterns of toxicity for a given radiotherapy modality. The pros and cons of conventional and advanced forms of radiation techniques and their clinical implementation are provided with a clinical perspective.

Abstract

The eye is an exemplarily challenging organ to treat when considering ocular tumors. It is at the crossroads of several major aims in oncology: tumor control, organ preservation, and functional outcomes including vision and quality of life. The proximity between the tumor and organs that are susceptible to radiation damage explain these challenges. Given a high enough dose of radiation, virtually any cancer will be destroyed with radiotherapy. Yet, the doses inevitably absorbed by normal tissues may lead to complications, the likelihood of which increases with the radiation dose and volume of normal tissues irradiated. Precision radiotherapy allows personalized decision-making algorithms based on patient and tumor characteristics by exploiting the full knowledge of the physics, radiobiology, and the modifications made to the radiotherapy equipment to adapt to the various ocular tumors. Anticipation of the spectrum and severity of radiation-induced complications is crucial to the decision of which technique to use for a given tumor. Radiation can damage the lacrimal gland, eyelashes/eyelids, cornea, lens, macula/retina, optic nerves and chiasma, each having specific dose–response characteristics. The present review is a report of non-cancer effects that may occur following ionizing irradiation involving the eye and orbit and their specific patterns of toxicity for a given radiotherapy modality.

[Indications for fluorescein angiography and optical coherence tomography angiography (OCTA) in medical retina: Changes from 2015 and 2018]

INTRODUCTION

Non-invasive multimodal imaging, including optical coherence tomography angiography (OCTA), has demonstrated high sensitivity and specificity for the management of retinal diseases. Since the availability of OCTA in 2015, we have developed a policy of "as little fluorescein angiography as possible". In this study, we describe the rate of OCTA and fluorescein angiography (FA) performed and their indications.

METHODS

Retrospective descriptive single-centre study. Chart review of patients examined for retinal disorders by one medical retina specialist between January 2015 and June 2018.

RESULTS

3487 patients were examined for a retinal disease. The charts of 651 of these patients (1170 eyes) were randomly selected for analysis (study group). The mean age in the study group was 72 years (60% female). Overall, OCTA and FA were performed in 49.4% and 6.5% of the studied eyes respectively. After the first year, the rate of FA decreased to 2%. The main indications for OCTA were age-related macular degeneration (AMD): 50%, central serous chorioretinopathy (CSC): 12% and retinal vascular occlusion: 10%. The most frequent indications for FA were AMD: 49%, diabetic retinopathy (DR): 18% and CSC: 14%. FA was performed in 16%, 11% and 10% of eyes diagnosed with DR, CSC and AMD respectively (P<0.05).

CONCLUSION

In routine practice, OCTA was performed in half of the eyes examined for a retinal disorder. The overall rate of FA was 6.5% and dropped to 2% after the first year of OCTA use. DR was the main disorder still requiring FA.