Radiation retinopathy intricacies and advances in management

Efficacy and safety of robotic Cyberknife radiotherapy in uveal melanoma: a systematic review and meta-analysis

OBJECTIVES

This systematic review is aimed to evaluate the efficacy and safety of robotic Cyberknife radiotherapy (CKRT) in the treatment of uveal melanoma (UM).

METHODS

Clinical studies published in English that assessed the efficacy and safety of robotic CKRT in UM were systematically searched in PubMed, Web of Science, Cochrane and Embase from inception to July 2023. Studies reporting extraocular tumours or other radiosurgery approaches were excluded. Outcomes measured were tumour size, reflectivity, local tumour control rate, eye retention rate, survival rate, complication rate, recurrence rate, and metastasis rate.

RESULTS

Ten eligible articles involving 2370 patients with 2372 UMs were included in evidence synthesis. Meta-analysis showed 811 of 912 patients (0.89, 95% Cl: 0.86, 0.92) maintained local control for three years, and 1448 of 1724 patients (0.84, 95% Cl: 0.81, 0.88) preserved the eye in three years. During follow-up, 91% (0.91, 95% Cl: 0.85, 0.97) patients survived and 351 of 1720 patients (0.23, 95% Cl: 0.09, 0.37) involving 1722 eyes had tumour recurrence. In addition, 1376 patients (0.79, 95% Cl: 0.77, 0.82) preserved the eyeball in five years. Following treatment, approximately 20% of patients had radiation retinopathy (95% Cl: 0.13, 0.28), 19% developed glaucoma (95% Cl: 0.11, 0.28), and 22% experienced retinal detachment (95% Cl: 0.07, 0.36).

CONCLUSIONS

CKRT is a viable, noninvasive RT for UM. The rate of local tumour control following treatment is comparable to that of other RT approaches, providing additional options based on the patient's condition.

Elucidating postoperative dynamics in tractional retinal detachment: a systematic review and meta-analysis of structural and functional outcomes following diabetic vitrectomy, including an analysis of postoperative complications

This meta-analysis aims to evaluate the efficacy and safety of diabetic vitrectomy for treating tractional retinal detachment (TRD) by assessing visual acuity improvements, retinal reattachment success rates, and the frequency of postoperative complications. A comprehensive literature search identified 1,211 studies, 30 of which met the inclusion criteria and were analyzed. The meta-analyses were conducted via random effects models to account for heterogeneity. The primary outcomes were visual acuity improvement and retinal reattachment success, whereas postoperative complications were analyzed as secondary outcomes. Funnel plots, trim-and-fill methods, and Egger's regression tests were employed to assess and adjust for publication bias. The meta-analysis included data from 1,844 eyes across 30 studies. The pooled mean difference (MD) in visual acuity following diabetic vitrectomy was 0.80 logMAR (95% CI: 0.58-1.01, p < 0.0001), with significant heterogeneity (I² = 95%). The trim-and-fill method adjusted the MD to 1.15 (95% CI: 0.85-1.45), indicating potential publication bias. The pooled proportion of retinal reattachment success was 94.63% (95% CI: 90.88-96.89%), with substantial heterogeneity (I² = 82.2%). Egger's regression test confirmed publication bias in the retinal reattachment data (t = 6.07, df = 25, p < 0.0001). The most common postoperative complications were vitreous hemorrhage (8.2%, 0-41%), elevated intraocular pressure (7.3%, 0-25%), and cataract formation (10.3%, 0-43%). Diabetic vitrectomy significantly improves visual acuity and achieves high retinal reattachment success rates in patients with TRD despite considerable heterogeneity across studies. However, a critical limitation of the current literature is the lack of comprehensive reporting of essential markers of perfusion, such as the choroidal vascularity index and choriocapillaris flow area, which are crucial for a thorough understanding of the impact of vitrectomy on ocular perfusion and its correlation with structural and functional outcomes. These findings also highlight the need for vigilant postoperative management to mitigate common complications. Adjustments for publication bias via the trim-and-fill method suggest that the initial estimates of efficacy may be optimistic, but the overall benefits of the procedure remain substantial. Further research is warranted to standardize surgical techniques, include detailed perfusion outcomes, and enhance the reliability of future meta-analyses. Trial registration: Retrospectively registered.

Radiation retinopathy vs. ocular ischemic syndrome: how to reach the diagnosis?

We present a case of diagnostic interest; we present the differential diagnosis and the complementary tests necessary to reach it, in addition to highlighting the importance of a correct collection of background and clinical history. A 54-year-old woman with a history of carcinoma of the floor of the mouth treated with radiotherapy and chemotherapy develops ischemic retinopathy. It was necessary to perform a systemic study and differential diagnosis with entities such as ocular ischemic syndrome and radiation retinopathy, due to the similarity in the clinical findings found. Radiation retinopathy should be ruled out in any patient with visual impairment and a history of radiotherapy treatment. A broad differential diagnosis and systemic study are required to rule out entities such as ocular ischemic syndrome and diabetic retinopathy, in addition to early treatment to avoid possible complications.

Efficacy of Intravitreal Injections Anti-Vascular Endothelial Growth Factor Treatment for Radiation Retinopathy: A Systematic Review and Meta-analysis

PURPOSE

This study aims to appraise the therapeutic effectiveness of intravitreal injections anti-vascular endothelial growth factor (anti-VEGF) vs alternative therapies in managing radiation retinopathy (RR).

DESIGN

Systematic review and meta-analysis.

METHODS

We obtained comprehensive data retrieval using PubMed, Embase, Web of Science, Scopus, and the Cochrane Library from their inception until December 15, 2023. This review included randomized controlled trials (RCTs) and nonrandomized studies (NRSs) reporting on best-corrected visual acuity (BCVA) among RR patients treated with intravitreal anti-VEGF. Study selection and data extraction were meticulously performed by 2 independent reviewers. The Cochrane Risk of Bias Tool 2.0 (RoB 2.0) and Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) scales were utilized for bias risk assessment. Quantification of heterogeneity was executed using Q, H, and I2 statistics. The primary endpoint was the BCVA at the final observation point of each study. Secondary endpoints included central retinal thickness (CRT), foveal avascular zone (FAZ) area, and capillary density (CD) at the level of superficial capillary plexus. Subgroup analyses were undertaken to explore potential heterogeneity sources possibly due to treatment duration and study design. Sensitivity analyses were conducted to ascertain result stability.

RESULTS

This analysis incorporated 7 studies (including 3 RCTs) encompassing 922 patients afflicted with RR. Relative to other treatment modalities, intravitreal anti-VEGF therapy was associated with a statistically significant mean decrease in BCVA of -0.34 logMAR (95% CI, -0.39 to -0.30 logMAR; I2 = 87.70%; P < .001), and a substantial reduction in CRT of -34.65 µm (95% CI, -50.70 to -18.60 µm; I2 = 30.40%; P < .001). Additionally, a reduction in the FAZ area by -0.69 mm² (95% CI, -0.91 to -0.46 mm², I2 = 0%; P < .001) was observed. A positive tendency was noted in CD at the superficial capillary plexus between anti-VEGF and other therapeutic interventions.

CONCLUSIONS

Intravitreal anti-VEGF injections, in comparison to other treatments, demonstrate superior efficacy in enhancing BCVA and reducing CRT, thereby underscoring the potential of anti-VEGF in ameliorating radiation retinopathy outcomes. However, the conclusions are constrained by the incorporation of data from some NRSs and the small sample sizes.

Role of inflammation in a rat model of radiation retinopathy

Radiation retinopathy (RR) is a major side effect of ocular tumor treatment by plaque brachytherapy or proton beam therapy. RR manifests as delayed and progressive microvasculopathy, ischemia and macular edema, ultimately leading to vision loss, neovascular glaucoma, and, in extreme cases, secondary enucleation. Intravitreal anti-VEGF agents, steroids and laser photocoagulation have limited effects on RR. The role of retinal inflammation and its contribution to the microvascular damage occurring in RR remain incompletely understood. To explore cellular and vascular events after irradiation, we analyzed their time course at 1 week, 1 month and 6 months after rat eyes received 45 Gy X-beam photons. Müller glial cells, astrocytes and microglia were rapidly activated, and these markers of retinal inflammation persisted for 6 months after irradiation. This was accompanied by early cell death in the outer retina, which persisted at later time points, leading to retinal thinning. A delayed loss of small retinal capillaries and retinal hypoxia were observed after 6 months, indicating inner blood‒retinal barrier (BRB) alteration but without cell death in the inner retina. Moreover, activated microglial cells invaded the entire retina and surrounded retinal vessels, suggesting the role of inflammation in vascular alteration and in retinal cell death. Radiation also triggered early and persistent invasion of the retinal pigment epithelium by microglia and macrophages, contributing to outer BRB disruption. This study highlights the role of progressive and long-lasting inflammatory mechanisms in RR development and demonstrates the relevance of this rat model to investigate human pathology.

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.

[Exogenously induced retinopathies]

Exogenously induced retinopathies can be caused by consumation of stimulating substances, systemic or ocular medications, vaccinations, light or irradiation. Some of the effects are transient, whereas other effects induce irreversible toxic reactions. Retinal damage may develop either acutely with obvious relation to the damaging cause, but often may take a long duration of repeated use of a substance or medication. External stimulants (e.g. nicotine, alcohol, poppers, methanol) are the most frequent cause of exogenously induced retinal damage. Side effects from systemic drugs (e.g. hydroxychloroquine, ethambutol, MEK-, ERK-, FLT3-, checkpoint inhibitors, didanosin, pentosanpolysulfat sodium) or intravitreally applied drugs (e.g. antibiotics, VEGF-inhibitors) are less frequent. Ocular side effects associated with vaccinations are rare. Ambient light sources induce no damaging effects on the retina. Incorrect use of technical or medical light sources (e.g. laser pointers) without adherence to safety recommendations or unshielded observation of the sun might induce permanent retinal damage. Local or external irradiation might induce retinal vascular damage resulting in radiation retinopathy.

Exogen bedingte Retinopathien

Exogen bedingte Retinopathien werden am häufigsten durch externe Stimulanzien, seltener durch unerwünschte Arzneimittelwirkungen systemisch oder intravitreal eingesetzter Medikamente und noch seltener durch Impfungen oder die Einwirkung von Lichtstrahlung verursacht. Die Kenntnis exogener Ursachen und ihre mögliche Symptomatik ist zur Prophylaxe oder zur Früherkennung schädigender Wirkungen und zur adäquaten Beratung der Patienten wichtig.