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Introduction Uveal melanoma is most commonly treated with radiotherapy, destroying the tumour cells with adequate safety margins and limiting collateral damage to surrounding structures to preserve maximal vision. We used optical coherence tomography (OCT) to study the effects of radiotherapy on the retina. Methods Patients with posteriorly located choroidal melanoma treated with proton beam radiotherapy (PBR) and ruthenium-106 brachytherapy between January 2010 and June 2014 underwent spectral domain OCT. Results Images of 32 patients following ruthenium-106 brachytherapy and 44 patients following proton beam teletherapy were analysed. Following plaque brachytherapy, an early marked disruption of the outer retinal layers could be observed in 30 cases (94%) with retinal atrophy evident in 26 cases (81%). In contrast, the images from patients who underwent PBR showed subtle outer retinal layer change with 16 cases (36%) showing some inner-outer segment junction disruption by 6 months and 63% by 24 months with minimal atrophy. In cases with tumours Conclusion In comparison to ruthenium-106 plaque brachytherapy, PBR leads to more subtle and slower changes in the outer retinal layers enabling retention of visual function for longer. The difference in dosing regime and dose distribution across the tumour is likely to be causative for this structural differential.

To compare the retinal morphological characteristics of eyes with choroidal neovascularisation (CNV) secondary to pathological myopia versus eyes with CNV secondary to age-related macular degeneration (AMD), using quantitative optical coherence tomography (OCT) subanalysis.Twenty-one eyes of 21 patients newly diagnosed as having CNV secondary to pathological myopia, and 43 consecutive cases of eyes with newly diagnosed subfoveal CNV secondary to AMD were retrospectively collected. In all patients, StratusOCT images and fluorescein angiograms (FA) were available for analysis. StratusOCT images were analysed using custom software (termed "OCTOR"), which allowed calculation of the thickness/volume of the neurosensory retina, subretinal fluid (SRF), subretinal tissue (SRT) and pigment epithelial detachments (PEDs). FA images were used to calculate CNV leakage area and CNV lesion size for each eye.The total volume of neurosensory retina in the pathological myopia group was significantly less than in the AMD group (7.10 (SD 0.50) mm3 vs 7.76 (0.93) mm3, p = 0.004). The total volume of SRF in the pathological myopia group was less than in the AMD group, but the difference was not statistically significant (0.33 (1.38) mm3 vs 0.55 (0.82) mm3, p = 0.434). The total volume of SRT in the pathological myopia group was less than in the AMD group, but the difference was not statistically significant (0.16 (0.15) mm3 vs 0.36 (0.60) mm3, p = 0.144). The total volume of PED in the pathological myopia group was markedly less than in the AMD group (0.01 (0.03) mm3 vs 1.09 (1.89) mm3, p0.001). On FA, the total leakage of CNV in the AMD group was significantly greater than in the pathological myopia group (4.17 (3.29) DAs vs 0.53 (0.58) DAs, p0.001).CNV lesions in pathological myopia were associated with considerably less retinal oedema, SRF and SRT compared with CNV associated with AMD. PEDs were almost negligible in myopic lesions compared with AMD. These findings are consistent with previous clinical and angiographic descriptions of myopic CNV as relatively small lesions with modest exudation.