Mouse model of radiation retinopathy reveals vascular and neuronal injury

PURPOSE

To characterize the neuronal and vascular pathology in vivo and in vitro in a mouse model of radiation retinopathy.

METHODS

C57Bl/6J mice underwent cranial irradiation with 12 Gy and in vivo imaging by optical coherence tomography and of relative blood flow velocity by laser speckle flowgraphy for up to 3-6 months after irradiation. Retinal architecture, vascular density and leakage and apoptosis were analyzed by histology and immunohistochemistry before irradiation or at 10, 30, 240, and 365 days after treatment.

RESULTS

The vascular density decreased in the plexiform layers starting at 30 days after irradiation. No impairment in retinal flow velocity was seen. Subtle perivascular leakage was present at 10 days, in particular in the outer plexiform layer. This corresponded to increased width of this layer. However, no significant change in the retinal thickness was detected by OCT-B scans. At 365 days after irradiation, the nuclear density was significantly reduced compared to baseline. Apoptosis was detected at 30 days and less prominent at 365 days.

CONCLUSIONS

By histology, vascular leakage at 10 days was followed by increased neuronal apoptosis and loss of neuronal and vascular density. However, in vivo imaging approaches that are commonly used in human patients did not detect pathology in mice.

Radiation-induced ophthalmic risks of long duration spaceflight: Current investigations and interventions

PURPOSE

As the average duration of space missions increases, astronauts will experience longer periods of exposure to risks of long duration space flight including microgravity and radiation. The risks from long-term exposure to space radiation remains ill-defined. We review the current literature on the possible and known risks of radiation on the eye (including radiation retinopathy) after long duration spaceflight.

METHODS

A PubMed and Google Scholar search of the English language ophthalmic literature was performed from inception to July 11, 2022. The following search terms were utilized independently or in conjunction to build this manuscript: "Radiation Retinopathy", "Spaceflight", "Space Radiation", "Spaceflight Associated Neuro-Ocular Syndrome", "Microgravity", "Hypercapnia", "Radiation Shield", "Cataract", and "SANS". A concise and selective approach of references was conducted in including relevant original studies and reviews.

RESULTS

A total of 65 papers were reviewed and 47 papers were included in our review.

CONCLUSION

We discuss the potential and developing countermeasures to mitigate these radiation risks in preparation for future space exploration. Given the complex nature of space radiation, no single approach will fully reduce the risks of developing radiation maculopathy in long-duration spaceflight. Understanding and appropriately overcoming the risks of space radiation is key to becoming a multi-planetary species.

OCT-A evaluation of the retinal and choroidal structures of patients with a history of radiotherapy due to nasopharyngeal carcinoma

BACKGROUND

To perform the optical coherence tomography angiography (OCT-A) evaluation of the microvascular structures of the retina and choroidal tissue in asymptomatic patients who received radiotherapy for nasopharyngeal carcinoma and to compare the results to those of healthy individuals.

METHODS

Ophthalmological examinations were performed in all asymptomatic patients without vascular or systemic diseases, or fundus findings who had received radiotherapy at least two years earlier. Then, OCT-A scans were obtained. Foveal, parafoveal, and whole retinal thicknesses, vessel densities in the superficial and deep capillary plexuses, subfoveal choroidal thickness, the non-flow area in the superficial capillary plexus, and the choriocapillaris flow area were measured and compared to the values of the healthy control group.

RESULTS

The radiotherapy group had significantly lower deep capillary plexus vascular density and subfoveal choroidal thickness values and significantly higher choriocapillaris flow area values compared to the control group.

CONCLUSIONS

We consider that OCT-A is useful in the early diagnosis of radiation retinopathy that may develop during follow-up in patients with nasopharyngeal carcinoma who have received radiotherapy.

Case Report: Optical coherence tomography angiography findings in radiation retinopathy

We reported the observation of a 31-year-old female followed for a nasopharyngeal carcinoma since 2009, treated by locoregional radiotherapy, with a cumulative dose of 75 Gray. The patient presented with a progressive decline in bilateral vision. Ophthalmologic examination revealed bilateral dry eye, posterior subcapsular cataract, radiation retinopathy, and optic neuropathy. The patient presented all ocular complications of radiotherapy. The most severe was radiation retinopathy. Performing optic coherence tomography angiography (OCT-A) earlier could have speeded up the diagnosis and led to a better prognosis. The OCT-A showed more pronounced macular edema in the right eye, and revealed enlargement of the central avascular zone and loss of the deep and superficial retinal vascular network. The patient received three consecutive monthly intravitreal injections of anti-vascular endothelial growth factor. Yet, we noted a non-improved visual acuity. The aim of this case report was to present the contribution of OCT-A in the diagnosis of radiation maculopathy and attribute these changes to ischemia at the level of the retinal vascular network.

Outcomes of Second-Line Intravitreal Anti-VEGF Switch Therapy in Radiation Retinopathy Secondary to Uveal Melanoma: Moving from Bevacizumab to Aflibercept

Introduction

Radiation retinopathy is a dose-dependent complication of the retina following exposure to ionizing radiation. The objective of this prospective case series is to determine the clinical efficacy of intravitreal aflibercept for radiation retinopathy secondary to radiotherapy for uveal melanoma in those that failed intravitreal bevacizumab treatment.

Methods

A case series of 30 patients with a mean age of 57 ± 15 years with radiation retinopathy were enrolled. Visual acuity (VA) and central foveal thickness (CFT) responses to therapy were assessed with regression analyses at 1 month, 3 months, and 6 months following the switch to aflibercept.

Results

Regression analyses showed a statistically significant reduction in CFT and improvements in VA following the switch to treatment by aflibercept at 1 month, 3 months, and 6 months. The mean CFT improved from 476 μm ± 170 to 386 μm ± 139 and the mean VA improved minimally from 20/115 ± 20/63 to 20/112 ± 20/54 over 6 months. After 6 months of aflibercept, 46% of patients displayed a CFT improvement of 100 μm or greater and 23% of patients showed improvement in VA of 1 line or better.

Conclusion

This pilot study suggests that patients with radiation retinopathy who have failed monthly intravitreal bevacizumab may respond to aflibercept.

Reduced blood flow by laser speckle flowgraphy after 125I-plaque brachytherapy for uveal melanoma

BACKGROUND

To determine whether reductions in retinal and choroidal blood flow measured by laser speckle flowgraphy are detected after 125I-plaque brachytherapy for uveal melanoma.

METHODS

In a cross-sectional study, retinal and choroidal blood flow were measured using laser speckle flowgraphy in 25 patients after treatment with 125I-plaque brachytherapy for uveal melanoma. Flow was analyzed in the peripapillary region by mean blur rate as well as in the entire image area with a novel superpixel-based method. Relationships between measures were determined by Spearman correlation.

RESULTS

Significant decreases in laser speckle blood flow were observed in both the retinal and choroidal vascular beds of irradiated, but not fellow, eyes. Overall, 24 of 25 patients had decreased blood flow compared to their fellow eye, including 5 of the 6 patients imaged within the first 6 months following brachytherapy. A significant negative correlation between blood flow and time from therapy was present.

CONCLUSIONS

Decreases in retinal and choroidal blood flow by laser speckle flowgraphy were detected within the first 6 months following brachytherapy. Reduced retinal and choroidal blood flow may be an early indicator of microangiographic response to radiation therapy.

Longitudinal optical coherence tomography angiography (OCT-A) in a patient with radiation retinopathy following plaque brachytherapy for uveal melanoma

Purpose

Patients with choroidal melanoma treated with brachytherapy lose vision over time due to radiation retinopathy and optic neuropathy. Newer imaging modalities such as optical coherence tomography angiography (OCT-A) may provide further insight into the ultrastructural vascular changes that occur over time. We studied the progressive OCT-A derived reduction in capillary density that occurred in the macula and juxtapapillary region of a patient treated with plaque brachytherapy for posterior uveal melanoma.

Methods

A patient with medium-sized choroidal melanoma in the inferonasal mid-periphery of the right eye was followed with OCT-A imaging in addition to standard imaging (color fundus photography, standardized echography, OCT) over a four-year time period following brachytherapy. Images were analyzed to measure vascular density in nine discrete areas of the macula at each time point as a function of region-specific radiation dose.

Results

OCT-A over time showed focal capillary loss and enlargement of the foveal avascular zone in addition to vascular re-modeling. These changes progressed over time despite improvement in the clinical markers of radiation retinopathy (cotton wool spots, retinal hemorrhages). Radiation dose significantly correlated with rate of reduction in vascular density assessed within 9 square sectors of the macula, and was greatest in sectors closest to the plaque, which had received the highest radiation dose. There was no change in the choriocapillaris flow area over time. The patient developed cystoid macular edema, but maintained 20/30 vision.

Conclusions and Importance

Longitudinal OCT-A demonstrates the microvascular changes that occur in response to radiation over time. Identification of these features may help define therapeutic windows to prevent vision loss associated with radiation retinopathy and optic neuropathy. Ongoing studies will describe a larger cohort of patients followed with this modality over time.

Radiotherapy and Radiosurgery in the Management of Optic Nerve Sheath Meningiomas: An International Systematic Review and Meta-Analysis of Twenty Studies

BACKGROUND

Optic nerve sheath meningiomas (ONMs) are often managed with radiotherapy (RT) with the goal of achieving radiographic local control (LC) and preventing deterioration of visual acuity (VA). We aimed to perform a systematic review and meta-analysis of outcomes for patients with ONM treated with RT.

METHODS

The PICOS/PRISMA/MOOSE selection criteria were used to identify studies. Primary outcomes were stable or improved VA and radiographic LC at last follow-up. The secondary outcomes were incidences of radiation-induced retinopathy and xerophthalmia and stable or improved visual fields (VFs). Weighted random-effects meta-analyses using the DerSimonian and Laird methods were conducted to characterize effect sizes. Mixed-effects regression models were used to examine potential correlations between gross tumor volume (GTV) and outcomes.

RESULTS

In total, 444 patients with ONM across 20 published studies were included. The estimated LC rate was 99.8% (95% confidence interval [CI], 98.3%-100%), and the estimated proportion of patients with stable or improved VA or VF was 89.7% (95% CI, 86.2%-92.4%) and 93.3% (95% CI, 89.5%-95.8%), respectively. Estimated incidences of radiation-induced retinopathy and xerophthalmia were 7.2% and 10.1%, respectively. GTV was significantly associated with VA (P = 0.014) with estimated VA rates of 96.4%, 91.4%, and 80.5% for GTVs of 2.0, 3.0, and 4.0 cm³, respectively.

CONCLUSIONS

RT was well tolerated, with excellent LC achieved. Nearly 90% of patients noted either stability or improvement in VA and VF. Larger ONMs were associated with poorer VA.

Radiation retinopathy intricacies and advances in management

Background: Radiation retinopathy is a chronic, progressive, vision-threatening complication from exposure to various radiation sources. While several treatment modalities are available, proper management for this disease is a continuing challenge with no consensus on the most efficacious.Objective: The aim of this article is to provide an updated review of the published literature on the course of the disease, available treatments and their efficacies, frequency of regimen, core issues in patient management, and additional newer treatment modalities, including possible prophylactic approaches.Value: We also highlighted the challenges encountered with managing chronically treated patients through an analysis of a clinical case report on a patient who was treated for several years with different modalities after a diagnosis of radiation retinopathy.

Evaluation of radiation maculopathy after treatment of choroidal melanoma with ruthenium-106 using optical coherence tomography angiography

BACKGROUND

To assess the impact of brachytherapy on macular microvasculature utilizing optical coherence tomography angiography (OCTA) in treated choroidal melanoma.

METHODS

In this retrospective observational case series, we reviewed the recorded data of the patients with unilateral extramacular choroidal melanoma treated with ruthenium - 106 (¹⁰⁶Ru) plaque radiotherapy with a follow-up period of more than 6 months. Automatically measured OCTA retinal parameters were analysed after image processing.

RESULTS

Thirty-one eyes of 31 patients with the mean age of 51.1 years were recruited. Six eyes had no radiation maculopathy (RM). From 25 eyes with RM, nine eyes (36%) revealed a burnout macular microvasculature with imperceptible vascular details. Twenty-one non-irradiated fellow eyes from the enrolled patients were considered as the control group. Foveal and optic disc radiation dose had the highest value to predict the burnout pattern (ROC, AUC: 0.763, 0.727). Superficial and deep foveal avascular zone (FAZ) were larger in irradiated eyes in comparison to non-irradiated fellow eyes (1629 μm² vs. 428 μm², P = 0.005; 1837 μm² vs 268 μm², P = 0.021; respectively). Foveal and parafoveal vascular area density (VAD) and vascular skeleton density (VSD) in both superficial and deep capillary plexus (SCP and DCP) were decreased in all irradiated eyes in comparison with non-irradiated fellow eyes (P < 0.001). Compared with non-irradiated fellow eyes, irradiated eyes without RM had significantly lower VAD and VSD at foveal and parafoveal DCP (all P < 0.02). However, these differences at SCP were not statistically significant.

CONCLUSION

The OCTA is a valuable tool for evaluating RM. Initial subclinical microvascular insult after ¹⁰⁶Ru brachytherapy is more likely to occur in DCP. The deep FAZ area was identified as a more critical biomarker of BCVA than superficial FAZ in these patients.

Two-year results for ranibizumab for radiation retinopathy (RRR): a randomized, prospective trial

PURPOSE

To assess the efficacy of a treat-and-extend strategy with intravitreal ranibizumab for radiation-related macular edema.

METHODS

Forty eyes with radiation-induced macular edema and decreased visual acuity were enrolled in the phase IIb, prospective clinical trial and randomized into 3 cohorts: (A) monthly ranibizumab, (B) monthly ranibizumab with targeted retinal photocoagulation (TRP), or (C) as-needed ranibizumab and TRP. In year 2, all subjects entered a treat-and-extend protocol for ranibizumab. The primary outcome measure was mean change in early treatment diabetic retinopathy study (ETDRS) best-corrected visual acuity (BCVA) from baseline.

RESULTS

Through year 1, the mean change in ETDRS BCVA was significantly different between the three cohorts (p < 0.001); cohort A saw the largest gain with + 4.0 letters. Significant anatomic improvements were also seen in all cohorts. Comparatively, through year 2, cohorts A, B, and C had a mean change in ETDRS BCVA of - 1.9, - 3.9, and + 1.3 letters, respectively; additionally, no significant differences were found in absolute ETDRS BCVA across time (ANOVA, p = 0.123). Overall, 90% of eyes maintained VA 20/200 or better and 33.3% of subjects gained at least one line of vision. There were no significant differences in mean central macular thickness for any cohort compared to baseline (p = 0.09). The presence of retinal hemorrhage and intraretinal exudates stayed consistent from year 1 to year 2 for all cohorts.

CONCLUSIONS

Among eyes with radiation-related macular edema, a treat-and-extend regimen with ranibizumab may not result in as many visual and anatomic improvements as monthly injections. However, treat-and-extend still may prevent serious visual complications compared to historical controls.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02222610.

Radiation-Induced Ocular Surface Disorders and Retinopathy: Ocular Structures and Radiation Dose-Volume Effect

Purpose

This study aimed to evaluate the radiation-induced adverse effects on ocular structures in head and neck cancer patients and investigate the radiation dose-volume effects on the cornea, lacrimal gland, retina, optic nerve and chiasm.

Materials and Methods

A total of 38 eyes of 19 patients were included in this prospective, cohort study. All patients underwent complete ophthalmological examination in addition to contrast sensitivity, visual field and visual evoked potentials (VEP) tests. Ophthalmological examinations and psychophysical tests were performed in 6th, 12th, 18th, 24th months and in the last visit. The relationship between the ophthalmologic findings, and the radiation doses below and above the cut-off values was evaluated.

Results

Contrast sensitivity decrease and visual field deterioration were observed in 42% of the patients in the last visit (median 26 months) whereas a prolonged latency and decreased amplitude of P100 wave in VEP was observed in 58% and 33% of the eyes, respectively at 24th month. Totally 16 patients (84.2%) developed dry eye disease and eight of them received radiotherapy below tolerance doses and had mild to moderate dry eye findings. Radiation-induced retinopathy was observed in three of the eyes in eight patients who received radiation above tolerance dose.

Conclusion

Head and neck cancers treated with radiotherapy, resulted in various ophthalmic complications. All patients who are treating with radiotherapy should be evaluated by an ophthalmologist in terms of anterior and posterior segment damage, even if the radiation dose is below the tolerance limit.

PAMM and the ischemic cascade associated with radiation retinopathy

Purpose

To report a case of paracentral acute middle maculopathy (PAMM) and evidence of the ischemic cascade documented with spectral domain optical coherence tomography (SD-OCT) following radiation treatment of a choroidal melanoma.

Observations

A healthy young patient was evaluated for an asymptomatic choroidal nevus in the left eye. Fundus examination was remarkable for a choroidal melanocytic lesion that measured 1.8 mm in thickness by initial B-scan ultrasound. Clinical examination 6 months later showed growth of the tumor at several margins with new subretinal fluid, and a B-scan measured thickness of 1.9 mm. The lesion was diagnosed as a small choroidal melanoma and treated with gamma knife radiation with a dose of 3000 cGy. Sixteen months later, examination showed signs of radiation retinopathy including cotton wool spots and PAMM via SD-OCT and OCT angiography and evidence of the ischemic cascade (i.e., alternating zones of middle and combined middle and inner retinal layer infarction).

Conclusions

Radiation retinopathy can include signs of microvascular damage and ischemia including lesions such as cotton wool spots and PAMM. A case is presented in this report of radiation retinopathy with OCT evidence of PAMM and the ischemic cascade.

Influence of Ranibizumab versus laser photocoagulation on radiation retinopathy (RadiRet) - a prospective randomized controlled trial

Purpose

To demonstrate superiority of intravitreal ranibizumab 0.5 mg compared to focal and peripheral laser treatment in patients with radiation retinopathy for choroidal melanoma.

Methods

Inclusion criteria were as follows: patients with radiation retinopathy and visual acuity impairment due to radiation maculopathy accessible for laser therapy, age ≥ 18 years, and BCVA less than 20/32. The main objective was to study the change in best-corrected visual acuity (BCVA) over 6 months from ranibizumab 0.5 mg (experimental) compared to focal laser of the macula and panretinal laser treatment of the ischemic retina (control) in patients with radiation retinopathy in choroidal melanoma. The secondary objectives of the radiation retinopathy study were to compare functional and anatomical results between ranibizumab and laser group over 12 months and to measure the frequency of vitreous hemorrhage and rubeosis iridis.

Results

The intention-to-treat analysis included 31 patients assigned to ranibizumab (n = 15) or laser treatment (n = 16). In terms of BCVA at month 6, ranibizumab was superior to laser treatment, with an advantage of 0.14 logMAR, 95% CI 0.01 to 0.25, p = 0.030. The positive effect of ranibizumab disappeared after treatment was discontinued. Similar results without statistically significant difference were found with respect to macular thickness. In both groups, no change was observed at month 6 in the size of ischemia in the macula or periphery compared to baseline. There was 1 case of vitreous hemorrhage in the laser group and no case of rubeosis iridis over time.

Conclusions

This study showed a statistically significant improvement in visual acuity and clear superiority of ranibizumab compared to laser treatment up to 26 weeks, but this effect disappeared at week 52 after completion of intravitreal treatment. Ranibizumab and PRP are considered equivalent in terms of the non-appearance of proliferative radiation retinopathy during the study.

Trial registration

EudraCT Number: 2011-004463-69

Electronic supplementary material

The online version of this article (10.1007/s00417-020-04618-7) contains supplementary material, which is available to authorized users.

Gamma Knife Radiosurgery for Uveal Melanoma: A Retrospective Review of Clinical Complications in a Tertiary Referral Center

Introduction

Gamma knife radiosurgery (GKR) has shown promising results in the treatment of intraocular uveal melanoma (UM) in terms of local tumor control. However, GKR is not free from potentially sight-threatening side effects, including cataract, dry eye disease, vitreous hemorrhage, radiation retinopathy (RR), radiation maculopathy (RM), optic neuropathy, and neovascular glaucoma. The aim of this paper is to report our 20-year experience in UM management with GKR focusing on the rate of clinical treatment-induced complications.

Methods

Single-center, retrospective, observational study, including all patients with UM treated at the Ocular Oncology and Uveitis Service, in the Department of Ophthalmology of the San Raffaele Scientific Institute, Milan from September 1993 to September 2018. Clinical charts comprised complete ophthalmological examination with measurement of best-corrected visual acuity, slit-lamp biomicroscopy, intraocular pressure measurement, gonioscopy, and indirect ophthalmoscopy at each visit. B-scan ultrasound (Aviso S, 10 MHz probe; Paris, France), optical coherence tomography (Heidelberg Spectralis; Heidelberg Engineering, Heidelberg, Germany), retinography, and fundus fluorescein angiography (standard or ultra-widefield [UWF; California, Optos, Dunfermline, Scotland, UK]) were performed aiding in the diagnosis of complications.

Results

Overall, 194 patients (100 males, 51.6%) were reviewed. The median age at the time of the treatment was 65 years (range 27-89) and all participants were Caucasian. In 185 eyes (95.4%), the tumor was primarily located at the choroid. The median follow-up was 57.6 months; radiation-induced complications were found in 145 eyes (74.7%). Radiation-induced cataract and RR were the most frequent events, with a relative incidence of 41.2 and 34.5%, respectively, followed by neovascular glaucoma (27.3%), optic neuropathy (18.6%), RM (11.4%), vitreous hemorrhage (14.4%), phthisis bulbi (7.7%), hyphema (0.5%), and corneal melting (0.5%). The shorter onset of side effects involved the optic nerve (median 14.9 months) and the macula (median 13.7 months).

Conclusion

Despite modern and advanced strategies introduced to limit GKR side effects, cataract and RR still represent a serious limitation of this treatment. Incidence of RR was higher in our cohort compared to other reports, probably due to increased diagnosis rate permitted by UWF retinal imaging.

Evaluation of early changes of macular function and morphology by multifocal electroretinograms in patients with nasopharyngeal carcinoma after radiotherapy

OBJECTIVE

To assess the role of multifocal electroretinograms (mfERGs) and optical coherence tomography (OCT) for detecting early changes in macular functions of patients with nasopharyngeal carcinoma (NPC) after radiotherapy.

METHODS

mfERGs and OCT were used to examine a NPC group (36 NPC patients after radiotherapy without clinically visible radiation retinopathy, 36 eyes) and a normal control group (25 healthy individuals, 25 eyes) with the same procedure and parameters. The two groups of mfERG were summarized by calculating ring averages, response density, N1 amplitude and P1 and N1 latencies were analysed. OCT scan thickness was summarized into ETDRS regions for comparison.

RESULTS

Compared with controls, the NPC group had significantly decreased P1 response densities in 1-4 ring regions and N1 amplitudes in 1-3 rings (P < 0.01). P1 latencies were obviously prolonged in rings 1 (P < 0.01). In four quadrants (inferonasal, superonasal, inferotemporal and superotemporal) of the mfERG response waveforms, the NPC group had significantly decreased P1 response densities and N1 amplitudes mainly in the inferonasal and inferotemporal quadrants, showing statistically significant differences from the control group (P < 0.0125). But for the OCT results, there is no statistically significant difference between the NPC group and the control group.

CONCLUSIONS

In NPC patients after radiotherapy, there may be changes in the mfERGs before any visible fundus lesions appeared as radiation macular oedema. Since the global OCT macular thickness analysis cannot reveal early changes, the mfERGs can objectively and quantitatively assess the earlier changes in macular function in NPC patients.

Outcomes of choroidal melanomas treated with eye physics plaques: A 25-year review

PURPOSE

To review long-term outcomes of the University of Southern California Plaque Simulator (PS) software and Eye Physics (EP) plaques. We hypothesize that the PS/EP system delivers lower doses to critical ocular structures, resulting in lower rates of radiation toxicity and favorable visual outcomes compared to Collaborative Ocular Melanoma Study plaques, while maintaining adequate local tumor control.

METHODS AND MATERIALS

Retrospective review of 133 patients treated for choroidal melanoma with ¹²⁵I brachytherapy, using PS software and EP plaques, from 1990 through 2015. A dose of 85 Gy at a rate of 0.6 Gy/h was prescribed to the tumor apex (with a typical margin of 2 mm) over 7 days. Primary outcomes were local tumor recurrence, globe salvage, and metastasis. Secondary outcomes were changes in visual acuity and radiation complications.

RESULTS

With median followup of 42 months, 5-year Kaplan-Meier estimated rates for tumor control, globe salvage, and metastatic-free survival were 98.3%, 96.4%, and 88.2%, respectively. Median doses to the macula and optic nerve were 39.9 Gy and 30.0 Gy, respectively. Forty-three percent of patients developed radiation retinopathy, and 20% developed optic neuropathy; 39% lost ≥6 Snellen lines of vision.

CONCLUSIONS

The PS/EP system is designed to improve the accuracy and conformality of the radiation dose, creating a steep dose gradient outside the melanoma to decrease radiation to surrounding ocular structures. We report favorable rates of local tumor control, globe salvage, metastases, and radiation complications when compared to the Collaborative Ocular Melanoma Study and other studies. Overall, the PS/EP system results in excellent tumor control and appears to optimize long-term visual and radiation-related outcomes after brachytherapy.

Quantification of radiation retinopathy after beam proton irradiation in centrally located choroidal melanoma

PURPOSE

To localize and quantify ischemic changes induced by proton beam irradiation of central choroidal melanoma and to identify baseline predictors correlated with the extent of ischemic changes.

METHODS

Retrospective chart review of patients with central choroidal melanoma treated by proton beam irradiation and conducted widefield fluorescein angiography (≥ 20 months after radiation therapy). Quantification and location of ischemic areas and correlation to baseline predictors. Multiple linear regression model was performed for analyses.

RESULTS

Twenty-five eyes from 25 patients were included in final analysis. Mean largest basal tumor area was 56.6 ± 40.0 mm² and mean maximal tumor prominence 2.5 ± 1.4 mm. Mean total radiated area was 339.1 ± 68.3 mm². All patients showed ischemic changes. Mean ischemic area was 387.6 ± 123.3 mm² and mean ischemic index (ischemic area/total visible area) was 0.53 ± 0.23. Twenty-two patients (88%) presented ischemic changes outside of the irradiation field, which comprised of 23% of total ischemic area. Mean angular distance between lateral border of irradiation field and ischemic area outside of the radiated area was 44.8 ± 36.5°. Multivariable analysis revealed a positive correlation of total ischemic area with total radiated area (p = 0.02) and initial sonographic tumor prominence (p = 0.02).

CONCLUSIONS

Ischemic changes induced by proton beam irradiation of central choroidal melanoma were localized and quantified. Ischemic changes exceed the tumor area distinctly and are found also outside of the irradiation field in the majority of patients. Size of irradiation area and tumor prominence are positively correlated with extent of ischemic area.

Radiation Retinopathy 47 Years following Brachytherapy for Retinoblastoma

A 50-year-old female who had undergone enucleation in the left eye and brachytherapy in the right eye for retinoblastoma at the age of 2 years was diagnosed with nonproliferation radiation retinopathy 47 years following the initial treatment. The patient had noticed black spots in her vision (scotomas) that interfered with reading. New onset of microaneurysms and lipid exudation threatening the foveola was noted on examination of the right eye. Initial visual acuity (VA) was 20/25. Optical coherence tomography showed no evidence of macular edema, but parafoveal lipid exudation was present. On fluorescein angiography, no sign of neovascularization or macular ischemia was observed. Direct focal treatment of microaneurysms was performed to prevent progression of the radiation retinopathy and vision loss. At 18 months' follow-up following focal laser, VA remained stable at 20/25 and there was a regression of the retinopathy.

[Adjuvant radiotherapy during anti-VEGF in neovascular age-related macular degeneration]

Single adjuvant radiotherapy during anti-VEGF therapy could be in certain indications an alternative to the gold standard of sole intravitreal anti-VEGF drug injection in neovascular age-related macular degeneration. First clinical trials showed efficacy due to reduction of anti-VEGF injection numbers by 100 kV collimated beam radiotherapy. After consideration and performance of adjuvant radiotherapy, results of the course should be centrally registered in order to carry out further analysis.

Exposing primary rat retina cell cultures to γ-rays: An in vitro model for evaluating radiation responses

Retinal tissue can receive incidental γ-rays exposure during radiotherapy either of tumors of the eye and optic nerve or of head-and-neck tumors, and during medical diagnostic procedures. Healthy retina is therefore at risk of suffering radiation-related side effects and the knowledge of pathophysiological response of retinal cells to ionizing radiations could be useful to design possible strategies of prevention and management of radiotoxicity. In this study, we have exploited an in vitro model (primary rat retinal cell culture) to study an array of biological effects induced on retinal neurons by γ-rays. Most of the different cell types present in retinal tissue - either of the neuronal or glial lineages - are preserved in primary rat retinal cultures. Similar to the retina in situ, neuronal cells undergo in vitro a maturational development shown by the formation of polarized neuritic trees and operating synapses. Since 2 Gy is the incidental dose received by the healthy retina per fraction when the standard treatment is delivered to the brain, retina cell cultures have been exposed to 1 or 2 Gy of γ-rays at different level of neuronal differentiation in vitro: days in vitro (DIV)2 or DIV8. At DIV9, retinal cultures were analyzed in terms of viability, apoptosis and characterized by immunocytochemistry to identify alterations in neuronal differentiation. After irradiation at DIV2, MTT assay revealed an evident loss of cell viability and βIII-tubulin immunostaining highlighted a marked neuritic damage, indicating that survived neurons showed an impaired differentiation. Differentiated cultures (DIV8) appeared to be more resistant with respect to undifferentiated, DIV2 cultures, both in terms of cell viability and differentiation. Apoptosis evaluated with TUNEL assay showed that irradiation at both DIV2 and DIV8 induced a significant increase in the apoptotic rate. To further investigate the effects of γ-rays on retinal neurons, we evaluated the expression of synaptic proteins, such as SNAP25 and synaptophysin. WB and immunofluorescence analysis showed an altered expression of these proteins in particular when cultures were irradiated at DIV2. To evaluate the effect of γ-rays on photoreceptors, we studied the expression of rhodopsin in WB analysis and immunofluorescence. Our results confirm data from the literature that differentiated photoreceptors appear to be more resistant to irradiation respect to other retinal cell types present in cultures. The results obtained suggest that γ-rays exposure of primary retinal cultures may contribute to shed further light on the mechanisms involved in γ-radiation-induced neurodegeneration.

Yellow Pattern 577-nm Micropulse Laser: Treatment of Macular Edema from Radiation Retinopathy - A Case Report

We report a case of a 60-year-old Asian male who developed radiation retinopathy 23 years after initial radiotherapy for nasopharyngeal carcinoma and was successfully treated with yellow pattern 577-nm micropulse laser. Secondary macular edema and visual acuity improved following a single treatment session with minimal scarring. Yellow pattern micropulse laser is a safe and effective treatment for macular edema secondary to radiation retinopathy.

Radiation retinopathy secondary to treatment of maxillary sinus carcinoma: a dramatic case

CLINICAL CASE

A 53-year old male presented with visual impairment in right eye after irradiation of right maxillary sinus carcinoma. Funduscopy shows radiation retinopathy: haemorrhages, exudates, macular oedema, and peripheral retinal ischaemia. A poor outcome was achieved despite laser treatment and intravitreal injections of bevacizumab, resulting in evisceration of the affected eye.

DISCUSSION

Radiation retinopathy must be considered in any loss of vision after head and neck irradiation. Ophthalmological long-term follow-up of these patients is essential for an early diagnosis.

Radiation maculopathy treated with intravitreal bevacizumab

CASE REPORT

A 47 year-old woman with a choroidal melanoma developed a macular oedema secondary to radiation therapy 75 months after brachytherapy plaque. The patient received 3 intravitreal Bevacizumab injections.

DISCUSSION

The patient had a good response to bevacizumab treatment. In fact, there was a reduction in the macular oedema measured by optical coherence tomography (OCT) scan, as well as an improvement in best corrected visual acuity. There was no recurrence of macular oedema, and visual acuity remained stable after 3-years follow-up.

23-mm iodine-125 plaque for uveal melanoma: benefit of vitrectomy and silicone oil on visual acuity

PURPOSE

To review outcomes in mostly large uveal melanoma treated with a 23-mm-diameter iodine-125 plaque, the largest size available at our center, and the influence of vitrectomy and silicone oil 1000 centistokes for radiation attenuation.

METHODS

A one-to-one matched case-control comparison was performed. Case patients were treated with a 23-mm-diameter iodine-125 plaque and vitrectomy with silicone oil 1000-cSt placement. Control cases, treated with 23-mm plaque alone, were matched to cases with respect to tumor size and distance from tumor apex to optic nerve and fovea. Postoperative complications, visual acuity and metastasis were reviewed.

RESULTS

Twenty case patients with uveal melanoma treated with a 23-mm plaque were identified. The final logMAR vision was 0.83 in case patients and 2.06 in control patients (P = 0.0064); the change from pre-treatment to last follow-up logMAR vision was 0.70 in cases and 1.62 in controls (P = 0.019). Of good vision outcomes, 65 % of cases and 25 % of controls achieved vision ≥20/200 (P = 0.025). Of poor vision outcomes, 35 % of cases and 80 % of controls achieved vision <20/200 (P = 0.0053), and 5 % of cases and 35 % of controls achieved "light perception" or "no light perception" vision (P = 0.044). Thirty-nine of the 40 eyes (98 %) achieved local tumor control. Metastasis occurred in 15 % of cases and 45 % of controls (P = 0.082).

CONCLUSIONS

Iodine-125 brachytherapy for mostly large uveal melanoma is effective in achieving local tumor control. Furthermore, combining brachytherapy with vitrectomy and silicone oil 1000-cSt for radiation attenuation significantly improves vision over the use of plaque alone.

Predictive risk factors for radiation retinopathy and optic neuropathy after proton beam therapy for uveal melanoma

PURPOSE

This study was performed in order to evaluate the incidence of radiation retinopathy and optic neuropathy occurring after proton beam therapy for uveal melanoma.

METHODS

Included in this study were all patients who had been treated with primary proton beam therapy for uveal melanoma at the oncology service between May 1998 and June 2014 with a minimum follow-up of 12 months. Excluded were all patients who underwent re-irradiation, or vitrectomy due to exudative retinal detachment or for tumor-resection.

RESULTS

During this period, 1127 patients matched the inclusion criteria, of whom 768 (68.1 %) and 463 (41.0 %) developed radiation retinopathy and optic neuropathy after a median time of 18.9 months (2.0-99.84 months) and 19.8 months (0.2-170.4 months), respectively. Mean follow-up was 53.4 months (12-170.4 months). Included were 558 men (49.5 %) and 569 women (50.5 %). Mean age was 61 years (16-89 years). Visual acuity slightly decreased from initial levels of 0.3 logMAR-0.4 logMAR in patients without developing any radiation-induced complication but severely decreased to 1.0 logMAR or 1.5 logMAR in the case of developing radiation retinopathy only or optic neuropathy, respectively. Independent risk factors for radiation retinopathy were a centrally (<2.5 mm from sensitive structures) located tumor or a thick tumor located more than 2.5 mm from sensitive structures, while those for radiation optic neuropathy comprised a short distance and applied dose to the optic disk.

CONCLUSION

The risk for radiation retinopathy is higher in central uveal melanoma. Mid-/peripheral tumors are at high risk for radiation retinopathy and maculopathy if presenting with increased thickness.

A case of radiation retinopathy of left eye after radiation therapy of right brain metastasis

A 37-year-old female, who had received modified radical mastectomy for cancer of her right breast, presented with decreased visual acuity in the left eye after radiation therapy for the management of the metastasis to her right brain 14 months ago. After ocular examination, we diagnosed her as radiation retinopathy. At the time of the first visit, the corrected best visual acuity was 0.4 in the left eye, and fundus examination revealed cotton wool spots and cystoid macular edema (CME). The findings in the right eye were normal except for cotton wool spots in the superior major arch. Fluorescein angiography (FA) showed marked telangiectasia and microaneurysms in her left eye but tiny microaneurysms in her right eye. Subsequent optical coherent tomography (OCT) showed CME. We injected intravitreal triamcinolone acetonide (TA). Two weeks after treatment, the visual acuity was improved to 0.6 and the retinal thickness was decreased. Three months later, the visual acuity in the left eye was dropped to 0.3 due to the recurrence of CME, so we injected intravitreal TA again. Five months later, visual acuity was improved to 0.5 and OCT revealed the improvement of CME. The incidence of radiation retinopathy is higher in the side nearer to radiation, but careful radiation blocking is also required on the opposite side of irradiation site considering the possibility of radiation retinopathy and careful observation is required on both sides of the eyes when performing fundus examination.