Konstantinos Balaskas

Analysis of significant factors influencing visual acuity in ocular syphilis

Background The aim of this study is to determine whether statistical associations can be demonstrated in ocular syphilis between baseline clinical and laboratory parameters with visual acuity at presentation and with any change in visual acuity after treatment. Methods Charts of 26 patients (42 eyes) with ocular syphilis presenting to the Uveitis clinic of the Jules-Gonin Eye Hospital were reviewed. A baseline cross-sectional analysis was performed in order to identify any association between visual acuity at presentation and demographic, clinical or laboratory parameters. After treatment, any analogy between these parameters and a change in visual acuity was subsequently assessed in a series of univariate comparisons. Results The following factors were associated with worse initial visual acuity: severity of visual field impairment at presentation (p=0.012), macular oedema (p=0.004) and optic neuropathy (p=0.031). There was a borderline association with the presence of vasculitis on fluroangiography (p=0.072). Improvement in best corrected visual acuity after treatment was significantly associated with the presence of vasculitis on fluroangiography (p=0.005), neurosyphilis, according to lumbar puncture findings (p=0.037) and marginally with anterior uveitis (p=0.070). Inflammation relapse was associated with the coexistence of pain as presenting sign (p<0.001) and with a longer duration of symptoms prior to the initial visit (p=0.023). Conclusions Severe ocular inflammation associated with vasculitis, vitritis or anterior uveitis in ocular syphilis would appear to be a reversible phenomenon that responds well to appropriate antibiotic treatment, resulting in improvement in visual acuity. Prompt treatment enables a good visual prognosis, while any delay in therapy increases the risk of subsequent relapse.

Ranibizumab for the management of Sorsby fundus dystrophy

Sir, Sorsby fundus dystrophy is a rare retinal dystrophy of autosomal-dominant inheritance characterized by central vision loss before the fifth decade of life, secondary to choroidal neovascularization (CNV) and/or pigment epithelium atrophy. The natural history of the condition involves early development of lesion fibrosis.1 The genetic background of the disease resides in a mutation in the tissue inhibitor of metalloproteinase 3 (TIMP3) gene.2 We report here a case of Sorsby fundus dystrophy successfully treated with repeated injections of ranibizumab.

Use of a Neural Net to Model the Impact of Optical Coherence Tomography Abnormalities on Vision in Age-related Macular Degeneration

PURPOSE To develop a neural network for the estimation of visual acuity from optical coherence tomography (OCT) images of patients with neovascular age-related macular degeneration (AMD) and to demonstrate its use to model the impact of specific controlled OCT changes on vision. DESIGN Artificial intelligence (neural network) study. METHODS We assessed 1400 OCT scans of patients with neovascular AMD. Fifteen physical features for each eligible OCT, as well as patient age, were used as input data and corresponding recorded visual acuity as the target data to train, validate, and test a supervised neural network. We then applied this network to model the impact on acuity of defined OCT changes in subretinal fluid, subretinal hyperreflective material, and loss of external limiting membrane (ELM) integrity. RESULTS A total of 1210 eligible OCT scans were analyzed, resulting in 1210 data points, which were each 16-dimensional. A 10-layer feed-forward neural network with 1 hidden layer of 10 neurons was trained to predict acuity and demonstrated a root mean square error of 8.2 letters for predicted compared to actual visual acuity and a mean regression coefficient of 0.85. A virtual model using this network demonstrated the relationship of visual acuity to specific, programmed changes in OCT characteristics. When ELM is intact, there is a shallow decline in acuity with increasing subretinal fluid but a much steeper decline with equivalent increasing subretinal hyperreflective material. When ELM is not intact, all visual acuities are reduced. Increasing subretinal hyperreflective material or subretinal fluid in this circumstance reduces vision further still, but with a smaller gradient than when ELM is intact. CONCLUSIONS The supervised machine learning neural network developed is able to generate an estimated visual acuity value from OCT images in a population of patients with AMD. These findings should be of clinical and research interest in macular degeneration, for example in estimating visual prognosis or highlighting the importance of developing treatments targeting more visually destructive pathologies.

Quantitative Analysis Of Pigment Epithelial Detachment Response To Different Anti–vascular Endothelial Growth Factor Agents In Wet Age-related Macular Degeneration

Purpose: To assess whether best-corrected visual acuity and pigment epithelial detachment (PED) height, volume, and reflectivity in patients with wet age-related macular degeneration are influenced by baseline anatomical and functional parameters, including quantifiable metrics of PED morphology and choice of treatment. Methods: One hundred two consecutive, treatment-naive wet age-related macular degeneration patients with PED (>50 &mgr;m) treated with aflibercept (52) or ranibizumab (50) were retrospectively included. Pigment epithelial detachment height, horizontal and vertical dimensions, and volume were recorded at baseline, 3 months, and 1 year, respectively. Bespoke image analysis software provided a quantifiable measure of reflectivity. Results: Best-corrected visual acuity at 3 months was influenced by baseline best-corrected visual acuity (P = 0.006). Pigment epithelial detachment height was influenced by baseline height (P = 0.009), subretinal fluid (P = 0.008), central macular thickness (P = 0.006), and use of aflibercept (P = 0.003) at 3 months and by baseline height (P = 0.018), volume (P = 0.017), vertical dimension (P = 0.0004), and aflibercept (P = 0.015) at 1 year. Pigment epithelial detachment reflectivity increased from 43.59 to 55.86 (3 months) and 57.35 (1 year) (P < 0.001) and was influenced by its baseline values and, interestingly, use of aflibercept at 3 months (P = 0.013). Conclusion: Quantifiable metrics of PED morphology improve with treatment, and PED content becomes hyperreflective, more so on aflibercept. Pigment epithelial detachments respond better in the context of more active disease. More hyporeflective PED content may predispose to better treatment response, especially with aflibercept.

Management of choroidal naevomelanocytic lesions: feasibility and safety of a virtual clinic model

Background Choroidal naevomelanocytic lesions are often identified as an incidental finding by community optometrists and referred for expert evaluation in hospital eye units or specialist ocular oncology centres. Optimal management strategy is undecided and most centres err on the side of caution. Our aim was to test a virtual model of service delivery relying on interpretation of imaging test results by non-medically trained graders. Methods Patients with naevomelanocytic lesions referred to Manchester Royal Eye Hospital and Moorfields Eye Hospital were retrospectively included in this study. All patients underwent imaging tests including optical coherence tomography and ultrasound and management was subsequently decided clinically. Images were anonymised and transferred to the Moorfields Eye Hospital Reading Centre and were reviewed by a trained, masked grader who reached a management decision on the basis of a specific grading protocol. Agreement between decisions made on the basis of clinical examination and imaging (‘gold standard’) by an expert ophthalmologist in the clinic was compared with the decisions made by a masked ophthalmologist and a masked non-medical grader based on imaging tests alone. Results There were 102 consecutive patients included in this study. Agreement between gold-standard clinical management and decisions made by masked, non-medical grader and masked ophthalmologist on the basis of imaging test results alone was 96.1% (κ=0.97) and 100%, respectively. Conclusions In this pilot study, a streamlined, dedicated, virtual service for rapid assessment (within 2 weeks of referral) of choroidal naevomelanocytic lesions was shown to be feasible and safe. Such a model of service delivery may prove cost-efficient while optimising patient experience. Further prospective studies are required for formal validation of the proposed service model.

Is indocyanine green angiography useful for the diagnosis of macular telangiectasia type 2

Macular telangiectasia (MacTel) type 2 is a bilateral disease of unknown origin exhibiting characteristic changes of the macular deep capillary network and neurosensory retina.1–3 Originally considered a predominantly vascular disorder, the introduction of novel imaging techniques has altered prevailing impressions of its underlying pathophysiology, suggesting a significant role of structural changes to the neurosensory retina. The MacTel study, a major multicenter observational study, attempts to shed light on the natural history of the disease and to identify optimal surrogates of disease progression that could be used as end points in interventional clinical trials. In view of the exploratory nature of the study, various imaging modalities were used at baseline and on annual follow-up visits to investigate their contribution to disease diagnosis and their role in offering clues on disease progression. These modalities included colour fundus imaging (CFI), fundus fluorescein angiography (FFA), autofluorescence imaging (AF), optical coherence tomography (OCT) and indocyanine green angiography (ICGA). All obtained images were sent to the Reading Centre at Moorfields Eye Hospital, UK, where the diagnosis was confirmed. During the MacTel study, it has been established that there are characteristic changes on CFI, AF, FFA and OCT that uniquely identify the disease.4 ,5 The primary aim of this project is to determine whether ICGA is helpful in establishing the diagnosis of MacTel and, therefore, whether its inclusion in the MacTel imaging protocol was justified. The secondary aim was to identify any changes specific to MacTel on ICGA over the course of …

Implementation of medical retina virtual clinics in a tertiary eye care referral centre

Background The increasing incidence of medical retinal diseases has created capacity issues across UK. In this study, we describe the implementation and outcomes of virtual medical retina clinics (VMRCs) at Moorfields Eye Hospital, South Division, London. It represents a promising solution to ensure that patients are seen and treated in a timely fashion Methods First attendances in the VMRC (September 2016–May 2017) were included. It was open to non-urgent external referrals and to existing patients in a face-to-face clinic (F2FC). All patients received visual acuity testing, dilated fundus photography and optical coherence tomography scans. Grading was performed by consultants, fellows and allied healthcare professionals. Outcomes of these virtual consultations and reasons for F2FC referrals were assessed. Results A total number of 1729 patients were included (1543 were internal and 186 external referrals). The majority were diagnosed with diabetic retinopathy (75.1% of internal and 46.8% of external referrals). Of the internal referrals, 14.6% were discharged, 54.5% continued in VMRC and 30.9% were brought to a F2FC. Of the external referrals, 45.5% were discharged, 37.1% continued in VMRC and 17.4% were brought to a F2FC. The main reason for F2FC referrals was image quality (34.7%), followed by detection of potentially treatable disease (20.2%). Conclusion VMRC can be implemented successfully using existing resources within a hospital eye service. It may also serve as a first-line rapid-access clinic for low-risk referrals. This would enable medical retinal services to cope with increasing demand and efficiently allocate resources to those who require treatment.

Associations between autofluorescence abnormalities and visual acuity in idiopathic macular telangiectasia type 2: MacTel project report number 5.

Purpose: The aim of this study was to determine whether typical abnormalities seen on autofluorescence (AF) imaging in patients with macular telangiectasia (MacTel) type 2 are correlated with visual acuity at presentation and with progression of visual loss over a 2-year follow-up period. Methods: A subgroup of 218 patients (413 eyes) enrolled in the MacTel study that underwent AF imaging was included in the present study. Images were graded at the Moorfields Eye Hospital Reading Center. Recorded AF abnormalities at baseline and at 2 years included the presence of increased AF because of loss of masking at the central macula, localized decreased AF at the end of a retinal vessel, and large area of decreased AF. Best-corrected visual acuity was measured using the Early Treatment for Diabetic Retinopathy chart at baseline and after 2 years. Statistical associations were sought by means of a generalized linear model. Results: Presence of increased macular AF (P = 0.004), a large area of decreased AF (P < 0.001), or decreased AF at the end of a retinal vessel (P < 0.001) at baseline were significantly associated with worse best-corrected visual acuity. Presence of increased macular AF (P < 0.001) or of localized decreased AF at the end of a retinal vessel (P < 0.001) and the absence of a large area of decreased AF (P < 0.001) were predictive of a subtle but significant drop in best-corrected visual acuity at 2 years. Conclusions: Increased central AF at baseline heralds worse best-corrected visual acuity and predicts further subtle visual loss in a period of 2 years, which, however, does not stand out from the overall slowly progressive natural history of the disease.

Differences in spectral absorption properties between active neovascular macular degeneration and mild age related maculopathy

This study examines the differences in spectral absorption properties between the maculae of patients with active neovascular macular degeneration and those with early age related maculopathy (ARM). Patients attending for management of neovascular age related macular degeneration (AMD) underwent multispectral imaging with a system comprising of a modified digital fundus camera coupled with a 250-W tungsten-halogen lamp and a liquid crystal fast-tuneable filter. Images were obtained at 8 wavelengths between 496 and 700 nm. Aligned images were used to generate a DLA (differential light absorption, a measure of spectral absorption properties) map of the macular area. DLA maps were generated for both eyes of 10 sequential patients attending for anti-vascular endothelial growth factor injections. Each of these patients had active leaking neovascular AMD in one eye and early ARM or milder disease in the fellow eye. Eyes with neovascular AMD demonstrated lower average levels of DLA compared with their fellow eyes with early ARM (p=0.037, t test). The significant difference in DLA demonstrates the potential of multispectral imaging for differentiating the two pathologies non-invasively.

Swept-Source Optical Coherence Tomography Angiography Findings in Torpedo Maculopathy

Torpedo maculopathy is a rare congenital anomaly of the retinal pigment epithelium (RPE). Various imaging modalities have been used to assess cases of torpedo maculopathy, including optical coherence tomography (OCT) and fundus autofluorescence (FAF). OCT angiography (OCTA) offers combined structural and flow characteristics of imaged lesions. The authors present OCTA findings in two cases of torpedo maculopathy. Common features include loss of RPE and choriocapillaris allowing greater visualization of larger vessels in the outer choroid. This confirms the potential of OCTA to provide greater detail of retinal and choroidal architecture and elucidate the histopathology of retino-choridal lesions. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:932-935.].