Real-world experience of using stereotactic radiotherapy combined with anti-vascular endothelial growth factor to treat neovascular AMD.

INTRODUCTION: Adjunctive treatment or longer-acting drugs are required to treat nAMD to help ease burdens for patients and hospital clinics alike. Stereotactic therapy is one such option, providing a reduction in the number of injections over time. OBJECTIVE: To determine the clinical outcomes in a cohort of patients with nAMD receiving a combination therapy of stereotactic radiotherapy (SRT) with intravitreal anti-VEGF injections (IVI). METHOD: A retrospective analysis of 74 patients with nAMD, who had received IVI and SRT (16 Gray maximum dose to the macula) at a large tertiary university eye hospital, between March 2018 and September 2019 was performed. The number of IVIs, visual acuity (VA), and central retinal thickness (CRT) were evaluated at 12, 24, and 36 months after patients received SRT and compared to the same time interval prior to SRT. RESULTS: Follow-up data at 12, 24, and 36 months following and prior to SRT was available for 74, 48, and 22 patients respectively. Overall there was a significant reduction in the number of injections post-SRT. Twelve months following SRT, the median number of IVI was reduced by 1 (p < 0.05). The reduction in the median number of IVI was significantly reduced by 3 and 6 injections at 24- and 36-month follow-up respectively (p < 0.05). The CRT was significantly reduced post-SRT compared to the baseline values at all time periods. There was no statistically significant difference in VA at 12-month follow-up compared to baseline. The VA, however, significantly decreased at 24- and 36-month follow-up (p < 0.05). CONCLUSION: A therapy combining SRT with IVI has shown an overall reduction in the number of injections required in nAMD patients at 12, 24, and 36 months following SRT compared to IVI treatment alone. These real-world outcomes are comparable to other studies while also confirming the maintenance of the reduced frequency of required IVI for patients with nAMD.

IMAGE ANALYSIS OF OPTICAL COHERENCE TOMOGRAPHY SCANS TO EXPLORE ESTABLISHED AND NOVEL CHOROIDAL FEATURES IN PATIENTS WITH CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: To explore the characteristics of choroidal tissue in patients with and without central serous chorioretinopathy (CSC) using an automated system of image analysis to determine known and novel metrics. METHODS: This was a retrospective case-control analysis of optical coherence tomography scans of patients seen at Manchester Royal Eye Hospital, UK, comparing patients with active CSC to an age-matched and gender-matched group with no CSC using a purpose-built automated system of image analysis. The expert system segments and measures established and novel features of choroid using a combination of thresholding, noise removal, and morphological techniques. RESULTS: A total of 72 patients were included in this study, with 40 included in the group with CSC and 32 patient controls with no CSC. There were significant increases from normal to CSC of median choroidal vascularity index, 54.7(median absolute deviation = 9.8) to 61.2(4.3), and all choroidal thickness indices including maximum depth, from 249.0(90.1) µm to 372.3(80.3) µm. For novel measures, there was a significant increase in tissue entropy from 6.68(0.28) to 6.95(0.17) and area of the largest five vessels from 6.28(3.04) mm2 to 9.10(3.49) mm2. The ratio of vessel lumen to stromal tissue intensity was conversely significantly reduced from 0.674(0.11) in normal patients to 0.59(0.06) in CSC. CONCLUSION: The automated system of choroidal analysis expands on the utility of known measures and introduces novel metrics. These findings contribute pathophysiological insights and metrics for further assessment and research on conditions affecting choroidal tissue.

Outcomes of screening for hydroxychloroquine retinopathy at the Manchester Royal Eye Hospital: 2 years' audit.

BACKGROUND: The Royal College of Ophthalmologists has produced guidelines for screening for hydroxychloroquine retinopathy. New imaging modalities had suggested an increased prevalence of retinopathy compared with previous reports. The aim of this study is to identify the real-life prevalence of hydroxychloroquine retinopathy in patients attending Manchester Royal Eye Hospital screening service over a 2-year period using The RCOphth diagnostic criteria. METHODS: Data were collected prospectively from all patients attending Manchester Royal Eye Hospital hydroxychloroquine screening service over the audit period. Results of Humphrey visual field tests, spectral-domain optical coherence tomography and fundus autofluorescence were collected as well as data on dose, indication, duration of treatment, and additional risk factors. Cases were identified as having definite, possible, or no retinopathy based on the 2018 RCOphth criteria. The data are not publicly available due to information that could compromise research participant privacy and confidentiality but are available upon request from the corresponding author. RESULTS: 910 patients attended for screening. 566 were identified as being at risk of retinopathy (543 had been on treatment >5 years, 10 had renal impairment, 12 were on doses of >5 mg/kg/day, and one was concurrently on tamoxifen). The prevalence of HCQ retinopathy was 10/910 (1.09%) of all those screened, and 1.76% of those at risk (10/566). Six patients of those deemed at risk were identified as having definite hydroxychloroquine retinopathy, while four had possible retinopathy. CONCLUSIONS: Our results show a prevalence of retinopathy largely consistent with reports from regional audits yet reveal a far lower estimate compared to previously reported figures.

Standardization of choroidal thickness measurements using enhanced depth imaging optical coherence tomography.

AIM: To describe and evaluate a standardized protocol for measuring the choroidal thickness (ChT) using enhanced depth imaging optical coherence tomography (EDI OCT). METHODS: Single 9 mm EDI OCT line scans across the fovea were used for this study. The protocol used in this study classified the EDI OCT images into four groups based on the appearance of the choroidal-scleral interface and suprachoroidal space. Two evaluation iterations of experiments were performed: first, the protocol was validated in a pilot study of 12 healthy eyes. Afterwards, the applicability of the protocol was tested in 82 eyes of patients with diabetes. Inter-observer and intra-observer agreements on image classifications were performed using Cohen's kappa coefficient (κ). Intraclass correlation coefficient (ICC) and Bland-Altman's methodology were used for the measurement of the ChT. RESULTS: There was a moderate (κ=0.42) and perfect (κ=1) inter- and intra-observer agreements on image classifications from healthy eyes images and substantial (κ=0.66) and almost perfect (κ=0.86) agreements from diabetic eyes images. The proposed protocol showed excellent inter- and intra-observer agreements for the ChT measurements on both, healthy eyes and diabetic eyes (ICC>0.90 in all image categories). The Bland-Altman plot showed a relatively large ChT measurement agreement in the scans that contained less visible choroidal outer boundary. CONCLUSIONS: A protocol to standardize ChT measurements in EDI OCT images has been developed; the results obtained using this protocol show that the technique is accurate and reliable for routine clinical practice and research.

Automated segmentation of the choroid in retinal optical coherence tomography images.

The choroid is a tissue layer at the back of the eye, which can be imaged by optical coherence tomography (OCT). Choroidal thickness has been proven to be correlated to several ophthalmic diseases in several studies. In this paper we proposed a novel segmentation technique to address this challenge. This technique firstly automatically segments the inner boundary of the choroid using a two-stage fast active contour model. It secondly allows a real-time human-supervised automated segmentation on the outer boundary of the choroid. Dice similarity coefficient (DSC) was used to evaluate the agreement between manual annotation and our automated measurements on 30 images captured from patients diagnosed with diabetes. The mean DSC value is 92.7% (standard deviation 3.6%) in the range of 85.5% to 98.1%. Results show that this new technique can achieve choroid segmentation with high accuracy.